What do you need to do to bring a 737 Max back in service after 6 months in storage?

Bringing any plane back into service will involve more or less the same things but vary in scope and scale depending on the size of the aircraft. It looks like Southwest is moving their 737's to their long term storage facility. Since its in the desert they may wrap/plug the engine inlets to prevent any debris/dust from getting in. This will need to be removed before the aircraft are brought back into service.

Aside from consumables like fuel, oil and hydraulic fluid, etc which are checked before every flight they will need to check all calendar-related maintenance items. Most aircraft maintenance items are tied to hours or cycles which don't really matter when the airplane sits, but some things are tied to the calendar and a sitting plane may lapse on checks and updates it needs. Off the cuff a plane sitting for a while may lapse or need replacement on:

Bi-annual Transponder Checks
Navigation/Terrain Database updates
Fire extinguishers past check/expiration
Expired Oxygen generation canisters
Expired slides/lifejackets (mostly the chemical inflator systems)
Batteries may need tending/replacement if run dead (or allowed to be run dead)

From a non-hardware standpoint, crew currency or type proficiency due to lack of flying hours on the airframe may land a chunk of pilots and FO's in the sim before the planes come back into service.

Jet fuel can grow bacteria in the tanks and a tank flush/purge may be done on aircraft that have been sitting for a long time depending on what they find when they get to the aircraft.

-----EDIT------

Since more information has been released since the original answer was posted. It now appears most airlines are expecting 100 - 150 hours of work to bring the current resting 737's back in to service after the software update gets approved. This only applies to the mechanical aspect, pilot training is still under debate:

  each aircraft will likely require between 100 and 150 hours of preparation before flying

  ....

  The preparations were discussed at a meeting between Boeing and MAX
  customers in Miami earlier this week, and include a list of items
  ranging from fluid changes and engine checks to uploading new 737 MAX
  software. The estimated time frame does not include pilot training,
  they said.


Why do cruise missiles look different than subsonic jet aircraft?

They are designed to fly at one Mach-altitude combination only. Regular aircraft have to take off and land (low Mach, low altitude) and cruise (high Mach, high altitude). Cruise missiles are launched either from aircraft or accelerated by a booster rocket so their flight starts at a high Mach number already. Next, their nap-of-the-earth flight means they never go high, but stay low for the whole duration of the flight.

To minimize wing surface and, consequently, drag, the cruise missile has a higher wing loading than any aircraft. The published data only gives mass and wing span, so I needed to guess the wing area:

BGM-109 Tomahawk: 1192.5 kg, 2.67 m wing span. If I assume an aspect ratio of 6, the wing area is 1.188 m² for a wing loading of 1004 kg/m².
Boeing AGM-86: 1430 kg, 3.7 m wing span. This one has an aspect ratio of maybe 10, so the wing area is around 1.37 m² for a wing loading of 1044 kg/m².

For comparison, a typical airliner wing loading is around 600 kg/m², which is also the maximum wing loading of the B-52. Using Wikipedia data, the maximum wing loading of the B-1B is even almost 1200 kg/m², but the published area is for the outer wing only, linearly extended to the center. If the large delta is added, the wing loading drops below 1000.

At the other end of the scale, typical glider wing loadings range from 30 kg/m² (without water ballast) to 55 kg/m² (with full water ballast). A typical GA airplane with a stall speed below 61 knots has 60 kg/m² to 70 kg/m², a TBM-700 can reach up to 180 kg/m² while jet fighters range between 300 kg/m² and 500 kg/m².

Next, the cruise missile needs to be stored, so it must be compact. In case of the Tomahawk, it is designed for the 21 inch torpedo diameter standard. The AGM-86 is mounted on a rotary launcher, and the trapezoidal fuselage cross section makes most use of the available space. Since it never needs a runway, the foldable fins can be arranged symmetrically for best control effectivity and to avoid cross coupling between yaw and roll. For maximum range the cruise missile stays out of the transsonic speed regime, so little to no wing sweep is needed. In the end, cruise missiles have a very straightforward and functional design.

AGM-86 on rotary launcher (picture source)


Does it make sense to do an emergency landing without nose gear in order to reduce stopping distance?

(Source)

That was the case on July 23, 1983 (but not quite).

It was luck the manual gravity-extension didn't lock the nose gear in position. That has been attributed to the shortening of the landing roll/slide.

  Two factors helped avert a potential disaster: the failure of the front landing gear to lock into position during the gravity drop, and the presence of a guardrail that had been installed along the centre of the decommissioned runway to facilitate its use as a racetrack.

However, no commercial aircraft is certified for it, because it can do more harm than good. And depending on the aircraft type, separate controls for each landing gear in manual-extension mode may not exist.

A hard landing without the nose-landing gear may rupture the fuselage, center fuel tank, or hydraulic lines. And with the added sparks from the sliding, that's a recipe for disaster.

Instead, a system such as the engineered materials arrestor system (EMAS) may help:

(Source) EMAS.


How can a modified ramjet produce static thrust without a turbine?

Well the Pratt & Whitney J58 engines which powered the SR-71 worked in a similar fashion, using a bypass system which allows the engine to operate as a ramjet at high speeds and a turbojet engine at lower speeds.

By the very nature of a ramjet, it relies of stagnation pressure at the intake and inlet throat to pressurize the airflow prior to combustion.  It is just not possible to achieve these kinds of stagnation pressures at speeds under Mach 2 or so.  There was an article in Air & Space magazine a while back about two enterprising Canadian teenagers who tried to fashion a homemade ramjet from iron sewer pipes to power a sled.  They couldn’t get the design to work for this reason.

As such, you would unfortunately need another type of engine to accelerate an aircraft to these fast speeds where a ramjet could work.  Turbojets work well for this application.  So do rocket boosters.  Injecting oxidizer would not be very useful here as airflow through the engine is not fast enough to ensure sustained combustion.


What usually happens is the crew doing the walkaround spots something that looks like damage, calls airline maintenance, and techs come look at it.  For a ding, they will consult the Structural Repair Manual guidance on allowable limits on dents.  Based on the SRM it may be ok to leave as is, or require repair, or require further evaluation.

If the SRM doesn't cover it, or not all the eventualities, they will call the OEM's product support organization for an assessment, repair scheme, and a temporary "fly-by" (a fix deadline) if feasible.  A really big airline may have its own internal structural engineering team with its own design approval authority up to some level of severity, in which case it's all done in-house.  Smaller airlines will call the OEM and pay the OEM for its engineering services.

In any case if it's outside the SRM limits, somebody somewhere with authority has to review the dent and decide what to do.

We don't really know what was done in the case you saw, so I'll speculate that the "ball of steel wool" you saw was actually the dent but looking like a bump due to lighting, and the area was probably roughened with Scotchbrite or something similar during the inspection, creating a steel wool look.  There could have been a Non-destructive Test done (usually dye penetrant) to look for cracks in the surface where the metal was bent, which would make the surface look different from the surrounding area with the treatment process.  Also if there were sharp defects like a gouge, there was probably some "blending" of the local material to minimize the stress riser effect of the gouge and the blending with emery cloth (sandpaper) would certainly leave a steel wool look to the area.


What does "leave clear on its left" mean in UK regulations relating to collision avoidance on non-runway landings?

Seems understandable to me.
It may be more clear with commas...
"(a) when landing, a flying machine or glider must leave clear, on its left, any aircraft which has landed, is already landing or is about to take off;"

Basically leave enough room between you and any aircraft which may be on your left as you pass them.

The grammar may be a little dated but still perfectly accurate.


What are the approximate glide angles for modern passenger jets?

It must be in the region between 1/5 (11.3°) and 1/10 (5.7°), and closer to the shallower angle. I guess you want the value at 1.3 times stall speed - without a speed an answer would be impossible.

Once the glide ratio drops below 1/5, the energy dissipation is too quick to allow rotation for a soft touchdown with idle thrust. On the other hand, a glide ratio much in excess of 1/10 will make the aircraft float along the runway in ground effect, which makes the precise selection of the touchdown point (at the correct touchdown speed) hard. Spoilers help to adjust the glide path angle to steeper values, so the aircraft with flaps and gear fully deployed but the spoilers in should have a glide angle around 5° to 7°.


Is there a best number of wheels per bogie?

The answer depends on who you ask. The structural engineer would prefer a single wheel, and as few legs as possible, while the aerodynamicist would vote for 8 or 12 wheels, because then the bogie has less frontal area and can be accommodated even in thin wings.

Generally, less than two wheels would compromise redundancy, and more are needed to reduce local ground pressure. Remember that the A-300B was initially not allowed on some US airports because of a slightly higher ground pressure. See this answer for more.

Modern designs use two wheels per strut for redundancy when the aircraft is light enough and replace them with a bogie with as many wheels as necessary to carry higher aircraft masses. The A-340-200 has gained a central strut with two wheels (A-340-200/300) rsp. a 4-wheel bogie (A-340-500/600), while the equally large, but lighter A-330 uses just the two 4-wheel main gears without the central gear. Airbus could have used two six-wheel bogies, but preferred to keep commonality with the A-330 gear.

More than 6 wheels per bogie is very unusual, but there are exceptions: Since the Tu-144 had no thrust reversers, all braking had to be done by the wheel brakes. Additionally, the bogies needed to fit between the intake ducts inside the nacelles, so the final design used 8 wheels with the large housings of the disc brakes sticking out towards the center of the bogie. As @Zeus points out in the comments, these were more precisely 4 dual-tire wheels per bogie: The two tires on each side were mechanically linked.

Tupolev Tu-144 landing gear (picture source). This particular aircraft is parked in the back yard of the Aviation Institute in Kazan. If you want to know how this 8-wheeled monster would fit inside a supersonic airliner, read the answers to this question.

XB-36 (first prototype of the B-36) taking off (picture source)

Convair experimented with different tire sizes for the B-36 and even a tracked version. The initial single wheel design resulted in the biggest aircraft tire ever produced, but in the end the conventional (but novel at this time) 4-wheel bogie was preferred because the single wheel had too much ground pressure for most US airbases. Earlier airplanes had used 2-wheel bogies (Tupolev TB-3, Junkers G-38) or a pair of wheels left and right of the strut (Douglas DC-4). Very early large aircraft had to use what was available, so the Caproni 42 bomber of 1918 below had as many main wheels as the TU-144 half a century later (picture source). The Zeppelin Staaken giant aircraft of WW I used the same number of main wheels on a single axle for soft field operations.

When Air India ordered their first A320s, they were afraid the main wheel pressure would be too much for some Indian airfields. Airbus produced a version with a four-wheel bogie instead of the usual two-wheel main gear of the regular A320. When they later ordered the A321, India seemed to have improved their airfields, because the newer planes use the regular two-wheel gear which is mechanically simpler and needs less maintenance.

Air India A320 (picture source)


You might have been seeing a general aviation aircraft from an orientation similar to the one pictured.

You'd see the left navigation light which would be red.

The rotating beacon would also be red, but if the airplane was positioned like this and the beacon was the rotating, not blinking type, you might just see two mostly constant red lights. Being that it was dark you might mistake the second red light for the navigation light on the other wing.

It is becoming more common on general aviation aircraft to have a pulse option on the landing lights. I flew for a 135 operation for a while under which our contract required this to be installed and operational for all our aircraft.

This seems to be the simplest explanation for what you are describing. If we consider Occam'z Razor it is likely to be what you saw on the occasion you described.


What is the validity duration of FAA Medical for international flights?

I believe the ICAO regulation you are thinking of is this one:

  Excerpts from ICAO Annex 1- Personnel Licensing

  “1.2.5.2 Except as provided in 1.2.5.2.1, 1.2.5.2.2, 1.2.5.2.3,
  1.2.5.2.4 and 1.2.5.2.5, a Medical Assessment issued in accordance with 1.2.4.5 and 1.2.4.6 shall be valid from the date of the medical
  examination for a period not greater than:

  60 months for the private pilot licence — aeroplane;  12 months for
  the commercial pilot licence — aeroplane;  12 months for the airline
  transport pilot licence — aeroplane;”

  It also indicates the following in a note:

  “Note 2 — When calculated in accordance with 1.2.5.2 and its
  sub-paragraphs, the period of validity will, for the last month
  counted, include the day that has the same calendar number as the date
  of the medical examination or, if that month has no day with that
  number, the last day of that month.”

  In ICAO Annex 1, 2.4.1.6, the medical requirement for a commercial
  pilot is prescribed. It states:

  “2.4.1.6 Medical fitness

  The applicant shall hold a current Class 1 Medical Assessment.”

  In ICAO Annex 1, 2.5.1.6, the medical requirement for an airline
  transport pilot is prescribed. It states:

  “2.5.1.6 Medical fitness

  The applicant shall hold a current Class 1 Medical Assessment.”

  “6.1.1 Classes of Medical Assessment

  Three classes of Medical Assessment shall be established as follows:

  a) Class 1 Medical Assessment; applies to applicants for, and holders
  of:  — commercial pilot licences — aeroplane and helicopter  — airline
  transport pilot licences — aeroplane and helicopter  — flight
  navigator licences  — flight engineer licences

  b) Class 2 Medical Assessment; applies to applicants for, and holders
  of:  — private pilot licences — aeroplane and helicopter  — glider
  pilot licences  — free balloon pilot licences

  c) Class 3 Medical Assessment; applies to applicants for, and holders
  of:  — air traffic controller licences.”

However, ICAO is not involved in enforcement but rather coming up with standards, which would then be enforced (if adopted) by the member country's aviation authority.

From the FAA:

  There are many differences to be aware of when flying outside the
  United States (U.S.). International Civil Aviation Organization (ICAO)
  rules prevail. Member states follow ICAO guidelines as published, with
  differences noted, in their official Aeronautical Information
  Publication (AIP).
  http://www.faa.gov/air_traffic/publications/ifim/intl_overview/

For example, the EASA (European Aviation Safety Agency) has rules very similar to the FAA:

  MED.A.055  Validity, revalidation and renewal of medical certificates
  (a)  Validity  (1)
  Class 1 medical certificates shall be valid for a period of 12 months.
  (2)
  Notwithstanding to paragraph (1) the period of validity shall be reduced to 6 months for pilots
  who:  (i)
  are engaged in singlepilot commercial air transport operations carrying passengers and
  have reached the age of 40  (ii)  have reached the age of 60
  (http://easa.europa.eu/rulemaking/docs/npa/2008/2008-17/NPA%202008-17c.pdf)

However, according to this report: http://dspace.mit.edu/bitstream/handle/1721.1/35725/FlightOpsICATfinal2.pdf,

  Air carrier operations are generally regulated by the country of
  registration and the sovereignty in which the operation is conducted,
  including the Federal Aviation Administration (FAA) in the USA and the
  Joint Aviation Authority (JAA) in Europe. International flights may
  also fall under the jurisdiction of ICAO (International Civil Aviation
  Organization) when operating abroad (U.S.-based carriers are governed
  by both FAA  and ICAO regulations when conducting international
  operations.)

So you might be legal until you hit the international waters.  At the very most you might be able to go abroad, but then not be legal to fly back.

The National Business Aviation Association (NBAA) recommends that pilots comply with the strictest interpretation of the law (so in this case, have the appropriate compliance with ICAO standards) to avoid having to explain the nuances between the two sets of regulations.
(http://www.nbaa.org/admin/personnel/medical/medical-certificates.php)


I think most people would say the answer is no. Consider the dictionary.com definition as it relates to Aeronautics:

  9. Aeronautics .
  a. one of a pair of airfoils attached transversely to the fuselage of an aircraft and providing lift.
  b. both airfoils, taken collectively.

The wings are the big airfoils which are responsible for generating most of the vertical lift.

A colloquial test of this definition would be to grab a CFI and ask him/her to "point out the wings on this airplane to me." They won't point out the propeller. (Not a scientific experiment)

However, both wings and propellers are airfoils (and so are the other wing-like surfaces such as the vertical and horizontal stabilizers). You might get some disagreement about whether those other surfaces are wings, but I believe the answer is still no. There is nothing to be gained by calling them wings, and only leads to ambiguity. We already have a word which describes lifting surfaces in-general, and again, it's airfoil.


What's the difference between a Sole Means Navigation System and a Primary Means Navigation System?

Sole means it is the only system, primary implies there is a secondary or even tertiary system, and supplemental means it supplements another system.


What is the requirement of a higher glidepath/approach angle and is this a flight safety issue?

The most important sources of noise in an aircraft (especially during landing) are the engines, the slats/flaps and the gear. An aircraft’s angle of descent has an effect on the noise experienced by people below. Steeper the angle, the less time an aircraft spends at low altitudes, which means that fewer people should be affected by higher levels of noise.

The reduction in noise (as experienced in Frankfurt airport) due to steeper (3.2$^{\circ}$) landing approaches are due to the following:

The aircraft is higher (compared to the 3$^{\circ}$ landing angle), and as a result, less noise is heard by the people below.
The deployment of flaps before intercept may also be 0.7 nm closer to the airport as the ILS intercept occurs 0.7 nm closer to the airport.
Thrust increase for a/c stabilization 0.3 nm closer to the airport; this results in lower noise. The thrust required was also reportedly lower.
Landing gear deployment is 0.4 nm closer to the airport (at the same height of 2000 ft)

The differences due to changing the glideslope to 3.2$^{\circ}$from the present 3$^{\circ}$ is shown in the following image:

Image from Experience with the steeper approach angle of 3.2 degrees - Presentation by DLR

As for safety, this system is expected to pose no problems as most aircraft and pilots are easily capable of doing this. As an added measure, the trial is only being carried out when visibility is good (Cat I) and the trial is optional (for aircraft using ILS anyway).

Some airports (like London City) have very steep landing approaches for clearing obstructions and may require special certifications and aircraft modifications.


What effect does a direct crosswind have on takeoff performance?

The effects of a constant crosswind up to the demonstrated value are insignificant (at least for airliners), as ymb1's answer already says. I checked some Boeing FCOMs and crosswind is never mentioned for takeoff performance calculation. It can therefore not have a significant impact. Boeing recommends this technique:

Any deviation from the centerline
during thrust application should be countered with immediate smooth and positive
control inputs. Smooth rudder control inputs combined with small control wheel
inputs result in a normal takeoff with no overcontrolling. [...]
Note: Excessive control wheel displacement during rotation and liftoff increases
spoiler deployment. As spoiler deployment increases, drag increases and
lift is reduced which results in reduced tail clearance, a longer takeoff roll,
and slower airplane acceleration.
[emphasis mine]

A gusty crosswind may however require larger control wheel inputs, which result in spoiler deployment. This will impact takeoff performance. Boeing therefore recommends to use more than the minimum required thrust in these situations:

For takeoff in gusty or strong crosswind conditions, use of a higher thrust setting
than the minimum required is recommended. When the prevailing wind is at or
near 90° to the runway, the possibility of wind shifts resulting in gusty tailwind
components during rotation or liftoff increases. During this condition, consider the
use of thrust settings close to or at maximum takeoff thrust.

Source: Boeing 737 NG FCTM 3.15 - Takeoff and Initial Climb - Crosswind Takeoff


Do aerodynamic forces depend on the materials of the wing surfaces?

Surface roughness has a minor impact, except in a range of Reynolds numbers mostly encountered in General Aviation. Only when you use an airfoil that has been designed for laminar flow but experiences an early transition will the performance be impacted significantly.

The book you quote assumes a certain minimum standard of build quality: Flush riveting, smooth surface and a solid, stiff structure. Once you move to more advanced topics, more variables will need to be added, such as elastic deformation in flight or substandard surface quality. At the introduction level some simplifications are justified. The lessons derived from this reasoning are valid and valuable. When you progress, they will be expanded with more complex concepts. Trust me.


Who is legally responsible for tiedown ropes?

I read this as "there is a place to park your plane for a while and tie it down if you are so inclined."  I do not expect the airport to provide the chains or ropes.  Some will, but small town or village airports are barely maintained and nobody is thinking about how to make life better for transient airplane owners.  If you intend to park and leave the plane for any length of time you should be carrying your own means of physically securing the airplane to the ground.
It's the pilot's responsibility to ensure the plane is safe.


Does the B787 (Dreamliner) operate with higher cabin pressure?

According to this document by Boeing:

Altitude: How High Is Just Right?
Today's airplanes are pressurized to a typical cabin altitude of 6,500
to 7,000 feet (1,981 – 2,133 m), with a maximum certification altitude
of 8,000 feet (2,438 m). Because the advanced composite materials that
make up the 787’s fuselage do not fatigue, the 787 can be pressurized
more, which allows for lower cabin altitude levels.
Studies at Oklahoma State University explored the effect of altitude
on passengers to determine optimum levels. After testing at various
altitudes, it became clear that lowering the cabin altitude to 6,000
feet (1,830 m) provided meaningful improvements. Lowering the cabin
altitude further, however, provided almost no additional benefit.
Based on that knowledge, Boeing designed the 787 to be pressurized to
a maximum cabin altitude of 6,000 feet.

So if we assume a constant altitude of 43,000 (the 787's service ceiling1), we would get a maximum differential of:

6,000 ft Cabin Altitude = 9.06 psi
8,000 ft Cabin Altitude = 8.11 psi

This would indeed be a higher cabin pressure than what Boeing considers "typical" at maximum altitudes.

1 It is probably actually an even bigger difference since the ceiling of a lot of airplanes isn't this high so the max differential would be even lower.


How are naval jets moved around below the deck of a carrier?

As Simon pointed out, they use tugs. Obviously the engines are not started below the deck as it would have potentially deadly consequences.

The tugs are either electric or powered by a diesel/JP-5 engine. For example, the USN uses the A/S32A-32 towing tractor (also called spotting dolly SD-2), among others.

Image from zone-five.net

This tug is powered by a diesel engine and controlled using a joystick. In order to be useful in the confines of the deck, the tug can rotate with a zero turning radius. The operation is pretty much similar to the other tugs- the tug is moved so that it lifts up the nosewheel, facilitating the aircraft movement.

The French, on the other hand use remotely controlled mototk tugs on board de Gaulle.

Image from mototok.com


Where can I get test samples for Assistant Air Traffic Controller Officer exam?

Based on the country you are looking for the certification, rules may be slightly changed. For India following syllabus is applicable (Source: atcguild.com)

At present it is a year-long ab-initio training (Under revision to make it in two sections of six months each)
Modules:

Air Traffic Services
Aerodromes and Ground Aids
Air Legislation
Meteorology
Communication Procedures
Technical
Search and Rescue
Air Navigation

The selection shall be made on the basis of a

Written test
50% questions on subjects relating to educational qualifications
prescribed
50% on General Knowledge, General Intelligence, General Aptitude,
English etc. Voice test
Personal Interview
Medical fitness as per ICAO Annex-1

I Googled for the subject, but didn't find much information on the paper patterns or example papers.


According to this website, which directly quotes an internal memorandum of the FAA, the class E airspace can be categorized as below:

E1 – Class E Airspace at and above 14,500 feet MSL
E2 – Class E
airspace areas designated as a surface area for an airport
E3 – Class
E Airspace Areas Designated As An Extension To A Class C Surface Area
E4 – Class E Airspace Areas Designated as an Extension to a Class D
or Class E Surface Area
E5 – Class E Airspace Areas Extending Upward
From 700 Feet Or More Above The Surface of The Earth
E6 – En route
Domestic Airspace Areas
E7 – Offshore Airspace Areas
E8 – Class E
Airspace Areas Designated As Federal Airways

The memorandum is also available as PDF.

Apart from this reference to the FAA internal memo, I could not find any official FAA documents explaining the categories.

For pilots and controllers there seems to be not many differences, but for operators of small unmanned aircraft (i.e. drones) there are.


Can I fly a glider in Europe on a Canadian Glider License?

In general, it is difficult to convert to EASA. You can find more information here however I suspect the easiest method will simply be for you to phone them up.

I think the bureaucracy will probably be more hassle than it's worth. It's not like Transport Canada where you can just get a FLVC (Foreign Licence Validation Certificate) or whatever (that was a pleasent suprise after our CAA in the UK!).


Why are KACV and KTLV depicted differently on sectional charts than KSGU, KBIH, and KTPL, even though each is E2 w/ E4 extensions?

It looks like the answer is "it's a mistake or inconsistency in the sectional charts".  Whether or not it's an outright mistake is debatable, but it certainly appears to be an inconsistency, and one can argue that the depiction used for KACV and KTLV provides some useful information that the depiction used for KSGU, KBIH, and KTPL does not.

It is the case that at KTLV-- but not at KACV or the other 3 airports mentioned here-- the description of the E4 airspace in the "Airspace Designations and Reporting Points" document has a note to see the A/FD for effective hours, while the E2 airspace has no such note.  The sectional chart has a similar notation, with an arrow pointing specifically to the E4 airspace.  (It also is the case that the current A/FD entry for KTLV simply reads "Airspace: Class E".)  It seems possible that the policy of the charting agency is to depict the adjoined E2 and E4 Class-E-to-surface areas as two distinct areas in any case where there is a possibility why their effective hours may be different.  If this is true, it doesn't explain why that style of depiction was also used for KACV.


How is GPS RAIM availability calculated?

The website that Ralgha points out is indeed the one to look at for the US. They also provide a SOAP interface should you want to create your own app for the IPAD.

For RAIM to be available, you need to check firstly that at least 5 satellites (Space Vehicles in GPS language) are visible from you position, or 4 if your RAIM algorithm uses Baro-aiding. They have to be well above the horizon. How much depends on your satellite receiver, the FAA uses 5 degrees on their website. There are some receivers that use a masking angle of only 3 degrees.

Orbital equations can be taken from the GPS interface control document, section 30.3.3.1.3. They take almanac data as input. Apart from the Space Vehicle orbits, you also need to take into account their health from the NANU's.

With the satellites available, you need to calculate the RAIM containment bound. This is the maximum size that a position error can grow due to a faulty satellite signal without the RAIM algorithm noticing it within 10 seconds (with a 99.9% probability). If that containment bound is more than 1 nautical mile, RAIM is said to be unavailable for terminal procedures. For NPA a 0.3 nautical mile radius is used.

The containment bound depends very much on the geometry of the satellites, more that on the number of satellites available.

The problem with the RAIM algorithms is that they aren't standardized. There are several ways to perform RAIM and because GPS manufacturers use proprietary solutions there is little information available to the public. So calculating the containment bound is where you will get stuck.

So there is no easy way to implement RAIM prediction on an IPad, apart from using the FAA website.

Europe has also a RAIM prediction website; AUGUR.


Is lift force less than weight during a descent?

The content reproduced in the question is basically exploring what happens if we suddenly bring the wing to the angle-of-attack required to produce some given G-load, while flying at some given airspeed.  The value of lift given in both cases -- 4166 pounds -- is undoubtedly NOT the weight of the microlight aircraft.  It is undoubtedly much higher than the weight of the microlight aircraft.  We are NOT looking at a situation here where net force and net acceleration are zero, so this content really doesn't shed light on the questions being asked.

On the content reproduced in the question, it's not clear why the asker believes that that the red arrow points to a climbing situation and the blue arrow points to a diving situation.  At any rate, the content reproduced in the question has nothing to do with the forces in a steady-state climb or descent.

As to the questions asked--

"Is lift force not supposed to be lesser than weight during a descent?"

Yes, both in a steady-state climb, and a steady-state descent, lift is less than weight.  To understand this better, keep in mind that in the context of winged flight, lift is defined to act perpendicular to the aircraft's flight path through the airmass, not vertically.  Similarly, the drag vector is defined to act parallel to the aircraft's flight path through the airmass, and to a first approximation, the thrust vector can often be considered to also act parallel to the aircraft's flight path through the airmass.  As a result, thrust supports part of the aircraft weight in a steady-state climb, and drag supports part of the aircraft weight in a steady-state descent, and in both cases the wing's lift vector is reduced.  To see the force vector diagrams illustrating these situations, visit these related answers to related questions:

What produces Thrust along the line of flight in a glider?

Does lift equal weight in a climb?

(Note-- to apply the vector diagrams shown in the first link above to the case of a powered glide or powered dive, simply replace the label "drag" with the label "drag minus thrust" –- much as the label "thrust minus drag" appears in the diagrams in the second link above.)

"Is descending at an airspeed much lower than the dive velocity (Vd) of the airplane affect the rate of descent of plane?"

Yes, for a given throttle position or a given thrust force or a given power output, if we change the airspeed, we'll change the rate of descent.  In general the slowest descent rate is obtained flying just a little faster than stall speed.


Can a sonic boom arrive before the source?

Assuming the aircraft you saw was traveling in a straight line, then the sonic boom you heard (assuming it was a sonic boom) could not have been generated from that same aircraft.  This is because the sonic boom is experienced at an angle back from the flight path of the aircraft.

Many aircraft which are capable of generating sonic booms also happen to fly in groups.  Fighter jets are a good example of this.  Fighter jets often train in groups of more than one aircraft.

It's possible you may have heard a sonic boom from another aircraft at a higher altitude which you did not see, then you later saw a new aircraft.  This is actually very likely, because sonic booms are much more common at high altitude.  The atmospheric conditions for creating sonic booms are favorable at high altitude.  This is because the speed of sound is much lower at high altitude compered to the speed of sound at low altitude.  It is difficult to see military aircraft at high altitude against a blue sky background because the military intentionally paints the skin of the aircraft in a grey color to make it difficult to see against a blue sky.  So without a con trail you likely did not see the fighter jet which was flying at high altitude.

Other commenters asserted supersonic flight is not allowed inside the US, but this is not entirely correct.  Many restricted airspaces in the US allow supersonic flight.  The restrictions on supersonic flight are generally put in place to balance the concern of noise pollution for the population.  Some MOA (military operating area) also allow supersonic flight, although usually only at high altitude.  Some areas of the eastern US which allow supersonic flight require the pilots to fill out a log stating supersonic flight occurred.  However, supersonic flight is easy to do accidentally in many fighter aircraft.  The pilot may not realize he was supersonic until reviewing the tapes after the flight.  Most airspaces allowing supersonic flight are over sparsely populated deserts of the western US.

Picture credit to Wikipedia


What does the Boeing 777 autopilot do after reaching the last programmed waypoint?

The first point I would stress on is that you don't program the autopilot. You program the FMS (Flight Management System), which looks like a very large calculator. In this picture it is the device under then first officer's hand.

On top of the PFD (Primary Flight Display) you see the MCP (Mode Control Panel). This is what controls the modes that the autopilot system will follow, here is another image of it:

Typically the entire flight plan is programmed into the FMC and then during various stages of flight, the autopilot is engaged to help with navigation.

This flight plan includes the departure, enroute waypoints or tracks, and then generally the arrival at the destination; but that is it - it does not include the runway information, etc (as this may be subject to change).

The FMC takes this information and other data (weight, fuel, temperature, weather, etc.) to calculate a flight plan which is then displayed; and the pilot will then select and activate a flight plan.

In most commercial flights however, the flight plan is already loaded in the FMC from the flight operations department and the pilots simply select the predefined flight plan. Punching in a large flight plan takes a significant amount of time so many times this is already downloaded from the flight ops center.

At any stage of flight, the autopilot may be armed and engaged to do one of many things - either maintain thurst, or heading, or control the climb/descent; or follow the flight plan. It may also be disarmed during any stage of flight.

If the autopilot is armed and it set to follow the FMC's flight plan; then after the last waypoint it will follow the waypoint heading.

So, if the last way point is a holding pattern, it will continue on that pattern. If the last waypoint was a marker it will reach that marker, and then continue at that heading and speed; even though there are no more commands coming to it from the FMC (since its at the end of the programmed flight plan).

Note that reaching the end of the flight plan from the FMC does not disengage the autopilot; there are many other things that might do that though.

All the above comes from my time in a 737 and 777 simulator.


May a student continue a discontinued checkride if the CFI who endorsed them voids that endorsement?

The test was discontinued. No reason the DPE would be looking in her logbook as a discontinuance is simply a pause in the testing process. She was eligible to test, she remains eligible to test. If she already told the DPE about this the smart DPE would make a note in her test records explaining what occurred. Once endorsed the applicant is endorsed. If the CFI wants to "revoke" her endorsement I believe it's too late.


How did Airbus A380 overcome corrosion issue in which aluminium wiring used?

The mechanisms by which aluminum corrodes are well-know and the measures needed to prevent it are similarly known to design engineers.

Aluminum corrosion via direct attack is an issue where the aluminum is exposed to air and the air contains moisture, and is made worse when salts are present in the environment and at certain pH ranges. It is prevented by encapsulating the aluminum in either an impervious coat of paint or plastic or a coating of intentionally-grown aluminum oxide. In an airplane, the insulation on the wire will prevent corrosion by direct attack.

Aluminum corrosion by galvanic action occurs when the aluminum is bonded directly to or in contact with a piece of metal that has a different position in the galvanic series, and the joint is wet or at least moist with water. You prevent it by excluding water from the joint by sealing the joint with glue or enclosing it in a housing that is airtight, and by coating the joint with a grease or oil that excludes water. In an airplane's wiring system, this would be done with a plastic plug-and-receptacle for the joint that keeps water out.

Electrical fires in wiring system connectors that contain aluminum wire joined with copper wire occur when the physical joint between them is vibrated or worked back and forth, which scrapes the native oxide off the aluminum in the joint, promoting more oxide growth which is scraped off, etc. which eventually leads to loading the joint with aluminum oxide and creating high contact resistance between the aluminum and the copper wire at the joint. I-squared-R heating at the degraded joint then sets the insulation on fire. This can also happen by temperature-cycling the joint which will cause the joint surfaces to be worked back and forth and once the joint begins to show resistance, then the heating occurs right inside the joint and the process accelerates itself.

In airplanes, houses, and cars where aluminum and copper wire must be joined, a special connector is used where the metals meet in which the crimp joint is exceptionally tight and the joint is loaded with a grease or chemical paste containing inhibitors that halt the oxidation of the aluminum.


Does anyone know if RHP (assumed to be rotor horse power) is equivalent to SHP (shaft HP)?

This answer is somewhat speculative, but I have strong grounds for the speculations, pls read through:
I've only ever seen bhp used as hp measured directly at engine output shaft, although by definition bhp can be measured at any location of the driveline:
Wikipedia: brake horsepower
In the particular case in question, I strongly believe the reason for the use of the obscure "Rhp" is the unusual way the powertransfer is arranged in this contraption: there is/seems to be no mechanical connection between the actual engine and the rotor. The rotor is actuated pneumatically by jets at the tips of the rotor blades.
There would be no point in measuring the brake horsepower or shaft horsepower of the actual engine due to "weird" power delivery.
It is therefore most likely the hp is measured at rotor hub, but since the rotor in this case sort of "is the engine itself", to avoid confusion, Rhp is used to declare power. The declared Rhp probably is shaft horsepower. Kinda confusing though :)
Note: several sources list rhp (with some variation in caps) to mean "rated horsepower, which according to Merriam Webster means "the maximum power an airplane engine can develop without failure when operated continuously or for a specified long period under specified conditions". Even with this definition, I think in this case it refers to hp measured at rotor shaft, produced by the tip jets.


Why is the horizontal stabilizer root interface designed this way?

It is a seal- to prevent entry of air into the stabilizer mounting area. For aircraft with trimmable horizontal stabilizers (THS), there is an opening to the rear of the aft bulkhead to allow for the movement of the THS. It can be seen in the following image for Boeing 787.

Boeing 787 aft fuselage structure; image from aero-news.net

Now, as the opening will be there while the THS moves, a seal has to be present to prevent entry of air (and FoD etc.). Boeing went ahead and put a hinge aperture sealing plate over that area, with only a small opening where the actuated area of the THS moves, with the seal inside the structure, as can be seen below.

777 THS area; image from deicinginnovations.com

Without cover, the are will look something like this:

Trimmable horizontal stabilizer region without cover, ; image from skysoftairlines.blogspot.in

Airbus, on the other hand went ahead and put a tailplane sealing plate outside the opening. This was used in the A330 and initial versions of A340 (which shared the fuselage with A330), before Airbus changed its mind and made the THS region similar to the other aircraft in A340-500 and -600 versions, where the horizontal stabilizer was redesigned.

Also, see these (1 & 2) patents and this discussion.


How long does a non-ETOPS flight need to be able to fly in an one-engine-out situation?

No, nothing addresses that case.

Let's say you're 20 minutes out from your destination, and because it's a clear VFR day you have minimum normal reserves -- roughly an hour of flying (on 2 engines, at medium-to-low altitude).  Those reserves are already prescribed for you by FAR's.  Now you lose the engine.  How long can you fly?  Until you run out of fuel or the other engine quits -- so in all probability, about that same hour, plus or minus.

Different case, you're over at Atlantic heading to Bermuda or the Azores or Iceland or NYC to the Caribbean, or over the Gulf of Mexico -- not ETOPS but a long ways from anywhere.  The fuel on board will be lots more, because you were planning for a much longer flight.  (And again, those fuel requirements are defined elsewhere.)  You now have the added twist of drifting down on one engine to a single-engine ceiling -- you set max continuous thrust on the good motor, and descend at a speed that gives you max range, which probably comes out to a few hundred feet per minute of descent.  Back in the flight planning, the check had to be performed that at the worst case, you could lose the motor, drift down, and continue to reach a suitable airfield without needing more gas than you'd have.  But in something like a 737, the gas you'll have on-board anyway is almost certainly more than sufficient.

But in this latter case, the time you can stay aloft is going to be hours -- way beyond what you had in the first case.

So no, the regulations don't prescribe a time that you have to be able to keep flying after losing one engine.  You DO have to be able to keep flying -- that's important -- and you have to have enough fuel to get to a destination with the one motor shut down.  But in terms of a prescribed time, that isn't given in the FAR's.


My guess is it is an urban legend. Ground based weather radar have been used track and analyse behaviour of birds. Part of this research was done with the radar in fixed beam mode to record individual wing beat frequencies for species identification, keeping the bird in the radar beam. If the birds would be scared away by the beam this research would be almost impossible (and invalid as well). Of course, that's no hard evidence that the birds aren't scared. Also the distance between the bird and radar plays a role of course.

The radar used for that research was operating in the C-band, which is also the frequency band that most aircraft weather radars operate in. Newer aircraft weather radars operate in the X-band, which is a higher frequency band. My gut feeling is that the higher frequency is even less likely to bother birds, but then again, I am not a bird so what do I know?

jwenting suggested in a comment that this myth might have been started because of incidents where animals and humans have been harmed and killed by high power radar transmissions.

The FAA has published an Advisory Circular on recommended practices and precautions for operating weather radar on the ground. While not concerned with birds, it provides an example calculations of the output power and safe distance of a weather radar. It the example, the safe distance is less than 4.5 meter. That is too close for a bird to avoid a mid air collision.


Why don't short-haul regional jets go for composites?

The C-Series has a carbon wing box.  The fuselage is aluminum but is a newer fairly exotic aluminum lithium alloy that is a bit lighter than 2024.  The decision to go with aluminum for the fuselage was mostly development and manufacturing cost (a fuselage requires a massive autoclave and it's development is fairly high risk the first time around) and ease of repair (the fuselage takes the brunt of vehicle damage on the ramp, especially on smaller aircraft) compared to carbon.

Cost is probably the number one driver.  They stuck with things like bleed air services, and wisely decided to avoid lithium ion batteries (Boeing had to use L-ion with the level of electric services).  The C-Series is overall a more conservative design than the 787, and it still almost broke the company, which was forced to give the airplane to Airbus for free or go under.

The E-jet is more or less the old 190 with a complete systems state of the art revamp (and I believe a new airfoil) that make it more or less a smaller C-series system wise without the risks of composites development.  An even cheaper choice, and a wise one on Embraer's part.


What are the pros and cons of a pulsejet?

The pulse jet engine works because it uses the dynamic pressure of air for compression. Consequently, it needs speed to work well. If the pulse jet is on the ground, it is not easy to start - it needs to be fed with compressed air, and once it runs (it can run even when not moving because the oscillating pressure wave inside the tube will compress the inflowing air), it develops litte thrust.

Thrust will go up with airspeed, so you need additional thrust sources for initial acceleration and take-off. In case of the V-1, this was done by a steam catapult or by air-launching the device. Note that the V-1 was accelerated to 370 km/h on a 45 m long catapult which means more than 100 m/s² (10g) average acceleration. Most of the development work went into making the airframe withstand this acceleration. A modern design would need additional engines as well, and once those are included, the rationale for pulse jets becomes very weak. They make sense if you have an air-launched, disposable application, such as long-range air-to-air missiles. This is a niche in which their higher-speed cousins, the ramjets, will still be used.

Pros:

Very easy to build, very light.
Runs and produces some thrust when at rest (as opposed to ramjets).

Cons:

Thrust grows with flight speed. This can be seen as a pro, but normally requires additional means of acceleration. Therefore listed as contra here.
Low fuel efficiency. The fuel energy is converted to other forms of energy: Just listen to the videos of Colin Furze to get an idea.
High levels of vibration due to the intermittent operation. When the Heinkel 280 was tried out with Argus pulsejets, the aircraft experienced unacceptable vibration.
Need heat-resistant materials. The central part will get very hot in operation, so at least nickel-chrome stainless steel is needed if air cooling is insufficient.
Cannot go supersonic. For this, there are ramjets.

EDIT:

NACA tested the As 014 pulse jet and wrote a report, from which the performance data depicted below is taken:

It seems that Bruce Simpson over in New Zealand has improved the pulse jet design a lot: He needs no compressed air for starting and makes clever use of surrounding cold air to increase mass flow and keep material temperatures down.


Typical Designs
You're starting out from a fairly mistaken idea of how things normally work. In particular, you're showing the horizontal stabilizer lifting upwards.
At least in most normal designs, the horizontal stabilizer does not lift upward at all. In fact, it's normally flying at a negative angle of attack, so its "lift" is actually pushing downward on the tail.
We normally start by looking at the center of lift (CP) of the wing by itself. That'll typically be somewhere around 40-45% of mean aerodynamic chord (MAC).
The CG is at least somewhat forward of that (25% of MAC is a pretty common starting point).
Then you trim the downward lift from the horizontal stabilizer to maintain level flight. The CP acts as basically the fulcrum point. We put the horizontal stabilizer at the end of a long tail to give it a lot of "leverage", so it doesn't have to generate much downward pressure to maintain level flight.
This is what gives static stability. If you stall the wing, it will lose lift. As the wing loses lift, the CG being so far forward will cause the aircraft to pitch nose down. That, in turn, will (at least normally) reduce the wing's angle of attack, so it will recover from the stall.
If the CG were arranged where you've shown it, behind the CP, you wouldn't get that automatic stall recovery--if the wing or (especially) the horizontal stabilizer stalled, the CG would be far enough back that the aircraft would tend to pitch nose up, increasing the angle of attack, stalling the airfoil even more deeply (a "deep stall", which is usually unrecoverable).
Alternative Designs
Although it's fairly unusual, you could do a design where you kept the CG somewhat behind the CP, but loaded the wing more heavily than the horizontal stabilizer. In this case, both the wing and the stabilizer would be lifting upwards, but since the wing is more heavily loaded, at higher angles of attack, the wing would stall before the stabilizer, and when that happened, the nose would drop.
To achieve the front wing being more heavily loaded than the rear, you typically end up having to shrink the front wing, and (to maintain overall lift) expand the rear wing. And that gives a canard design, such as the Rutan Vari-EZ and Long-EZ, and the Quickie Q2. Thanks to their use of canards, the Rutan designs are extremely stall resistant. The Quickie claimed to be completely stall proof (and as far as I know, that was accurate).


How to decide the diameter of a propeller and number of propellers needed in a UAV I am designing?

There is an analytical process for selecting a propeller, but in the most straightforward cases it begins first with the selection of the engine. The propeller choice then can be made almost immediately.
Since you state that the plane will be driven by a turboprop, you have greatly narrowed down the propeller possibilities, and once you have selected a horsepower requirement for your turboprop engine, you have automatically narrowed down the propeller choice even further. Then, once you have selected a particular turboprop engine from a specific manufacturer, your propeller choices are narrowed down to just a couple of possibilities.
Just about the only design choice remaining after you select, for example, a PT-6 with a certain shaft horsepower output specification, will be the prop diameter needed to achieve the correct ground clearance for the engine installation, which may (for example) dictate four blades to absorb the engine power for a small diameter blade disc rather than three blades for a larger diameter disc.
Note also that no prop manufacturer is going to design for you a custom prop from scratch unless you can guarantee the purchase of tens of thousands of propellers of that custom design, and the design process will require years to go from an empty CAD file to a certificated prop being bolted onto an engine.
From an engineering practicality standpoint, your best bet would be to select the engine and then choose the most commonly-used prop in current manufacture with the longest production run and the greatest number of units in the installed base.


Are there any English speaking flight schools to get a PPL in continental Europe?

Some years ago there were a couple of flight schools on Malta, I'm not sure if they are still operating, DuckDuckGo could probably tell you

The most common way of getting a JAR (pre-EASA) PPL (for UK trainees) outside the UK used to be to go to a JAR accredited school in the USA. Florida was very popular.  I expect there are schools in the US that are allowed to train to the EASA syllabus these days.  I think you need to travel on a training visa to do this and I'm not sure what is involved in getting one

I think I'm right in saying your flight test can be taken by an EASA examiner anywhere, no need to come home to do it (and anyway you'd want to do it over familiar territory)

A big warning to anyone learning to fly is not to pay upfront.  Pay lesson by lesson.  Flying schools can go bust very quickly, many students have lost a lot of money this way

Personally, I would be wary of training outside the UK, the weather conditions and procedures will be very different from what you are used to, and a low-hours pilot could easily get caught out.  Marginal conditions can go bad on you very quickly.  If you do do this, try to get some supplementary lessons in poorish weather and get some time fly through UK CAS to get used to ATC procedures


What are the effects of dihedral on net lift of a wing?

The effect of dihedral on lift can be obtained applying high school trigonometry:

$$
L=L_0 \, cos \,\theta
$$

where $L_0$ is the lift of the original flat wing and $\theta$ is the dihedral angle. This holds true for negative values of $\theta$ as well.

Since the cosine can be approximated by unity for small angles, the net effect is negligible in most practical cases, e.g. $ cos(5^o)= 0.996$


For electric aircraft, is MTOW = Empty weight + Maximum payload?

A maximum payload may be specified to be less than tested MTOW minus empty weight in some cases, as a precaution against conditions that may reduce MTOW -- which depends on strip elevation, barometer, and temperature.

The thinner (higher and hotter) the air, the less a given amount of power can lift, in the case of a quad-copter or similar aircraft, or the longer it will take to reach takeoff speed and the slower climb will be, in the case of a conventional winged drone (electric or otherwise, though at least electric motors don't lose power with altitude).  Responsible drone manufacturers may (and should) specify a maximum payload spec that will keep gross weight below the least MTOW for foreseeable conditions.

There may also be cases where, for one reason or another, payload is based on testing conditions different from your flight configuration -- for instance, if you're using a heavier battery pack than the one used for testing, you'll have less margin below MTOW than the test condition.  Payload limits may also be specified below MTOW minus empty weight for reasons of center of mass location, payload restraint limitations, or other engineering reasons.


What's field excitation in an electrical system?

To my knowledge the M2 uses a Williams FJ-44 engine which has a starter generator on it.  My recollection is that it is a 200A 28VDC starter-generator (SG) which is directly connected to the accessory drive (along with the oil pump).  If 24-28VDC is applied to it, it will start turning the turbine, for starting the engine. At a certain point, once the engine starts, it is switched so that no power goes into it, and instead power is derived from it to charge the battery and provide gen power to the bus.

A typical engine starter configuration is shown above, and is common in smaller turbine engines. Note that the starter generator functions as an electric motor, and also as a power source. (Ignore the circuitry for ignition, throttle relays, etc.)

The SG is NOT an AC generator as is common on transport sized aircraft.  It is also NOT an alternator, as is common to piston engine aircraft.

You may find the descriptions in this manual http://content.aviation-safety-bureau.com/allmembers/faa-h-8083-32-amt-powerplant/sections/chapter-5.php#4. helpful in general understanding of SG operation.  Some of the terms vary from SG vendor to SG vendor, but in general, they are DC motors, and when electric power is removed from them, and they are spinning, they will produce power. Some are self excited with residual magnetism and others utilize an internal circuit to take the small power created by residual magnetism to create a stronger field to create a larger output power from the generator.

Having said all of this, normally a field excitation coil, is the name attributed to an alternator field, which is a magnetic field created by current (not residual magnetism, and not a permanent magnet).  An alternator creates AC internally (not DC like a SG) and is then rectified by diodes which are almost always integral to the alternator. The alternator is usually a three phase device and will have 3 or 6 diodes for rectification. Alternators tend to be less than 150 amps, where SGs are typically 200 to 300 amp devices.

If the SG model is provided, perhaps a refined response is possible.


Why so much ground time at Frankfurt Airport?

Why bus
The typical reason you use a bus to your low-cost carrier (LCC) or regional jet is the cheaper 'remote stands'. But this doesn't mean the stand is necessarily closer to the runway where the planes take off and land.
See: Who decides whether an airline docks at a jetbridge or parks at a remote stand?
Can't be too close
A big area around the runway needs to be clear of tall tail fins, light poles, equipment, etc., as it may affect the navigation equipment near the runway or pose a hazard to landing/departing aircraft.
Example: Why do some airports park the aircraft backwards at the gate?
Queue
An LCC plane won't get ahead in line just because it's parked closer to the runway. If a plane at the terminal pushed back and started its engines before the one at a remote stand, it will typically be ahead by the time the LCC one is ready to go.
Shorter flights also typically use a more congested airspace (they don't fly too high, the flight is short, and it's busy near airports), so there might be a delay in releasing that flight.
Remote stand analogy
I'm not sure which remote stand you typically use, but also in airport design it's fairly common to have the remote stand share the same taxiway (the road planes use to get to the runway) as the terminal.

(Google Earth - FRA)
Think of it like this, there's a road with a mall and its fancy parking on one side (1), and the cheap parking across the road (2). Regardless of where you park, when it's time to reach the highway, cars from the two parking lots will eventually merge (3).

That being said, 15 minutes to taxi to the takeoff position on the runway (not including the time to start the engines and to get the taxi clearance) is actually really good for a major airport such as FRA. Jetliners typically take 90-degree turns at slower than 15 km/h, and 40 km/h is common for straight lines. With a taxi distance of 2.25 km (example shown above), we are looking at a delay of ~12 minutes. FRA handles ~74 movements per hour (takeoffs and landings), assuming they use 3 runways, it's a takeoff every 2.4 minutes on your runway, or like waiting behind 5 other planes.


Can a four-engine aircraft with limited fuel gain extra range by shutting down one of its engines?

Assuming the aircraft is always flying at its optimal Lift/Drag ratio (= optimal angle of attack = optimal speed for a given weight and altitude), then the question is:

Is it more efficient to generate a given amount of thrust T with 4 engines x T/4, or 3 engines x T/3?

I would think that in the general case, it is not the case. Specific Fuel Consumption tends to increase with thrust (at constant speed):

Note: the above diagram is for Turbofans (Source: Airplane Aerodynamics and Performance, Roskam). It would be interesting to have similar trends for other types of engines (turboprops, turbojets, piston engines), but I could not find any!

On the other hand, it is possible that, in this particular case, the engines were simply working too far off their design point, so increasing thrust was improving their SFC.

Also, there is a problem with cutting one engine: The pilot will need to counteract the thrust asymmetry with the rudder, and this will have a significant cost in drag. Of course, the pilot could just cut 2 engines instead of one! :-)


Is there a common template or mnemonic for a take-off briefing?

I have never used any checklist or Mnemonic for this, but I do use it as a sneaky way to make myself look professional to my passengers while really using it to remind myself what the hell I'm actually meant to be doing.

Typically it will contain the following

What will happen in the next 5 minutes ("We'll line up on the runway when told to.... we will begin rolling..... we will lift off at about [speed]")
What will happen immediately after take off ("We will climb until X, at which point I will turn [left|right] and head towards Y")
What the intention of the flight is ("We will continue via X & Y to Z")
Any quick emergency procedures which might be necessary (Much like your instructor demonstrated, along with briefly what the passenger should do in case of this emergency.)

I do this at the hold when with an instructor, or experienced pilot in the other seat. If its an inexperienced or nervous flyer I take longer about it, usually sitting in the aircraft prior to startup.


Are test pilots certified to fly all aircraft types?

Since you didn’t specify a jurisdiction, I’ll answer for the FAA. Others should be similar.
Pilots must be rated for the category, class and (if applicable) type of aircraft. Category is pretty broad, such as “Airplane”. Class is a bit more specific, such as “Multi-Engine Land”. Type is even more specific, such as “Boeing 737”.
A type rating is required for any type that:

has a Maximum Takeoff Weight (MTOW) of 12,500 pounds or greater, or
has one or more turbojet engines, or
has been designated by the FAA.

There is no limit to the number of ratings a pilot can have, aside from the time, money and skill required to pass a checkride for each one. However, type ratings are only available for certified aircraft.
For experimental (non-certified) aircraft, since no type ratings exist, the FAA can issue a Letter Of Authorization (LOA), which waives the type rating requirement for specific pilots in a specific plane for specific purposes, such as flight testing, training or demonstration.


Is there any limit by FAA on the age of aircraft to be operational?

It depends on the aircraft, but in general the answer is that there  are no regulatory age limitations, and indeed we have many aircraft flying that are 50+ years old.

A notable exception is the Robinson line of piston helicopters. The airframe on those helis is limited to 2200 hours or 12 years, whichever comes first, at which point the entire airframe must be completely overhauled. Some of the airframes are indeed rebuilt, but some are also scrapped, depending on level of wear and corrosion.

Since the airframe lifetime is in the LIMITATIONS section of the POH, it is governed by:

  § 91.9 Civil aircraft flight manual, marking, and placard
  requirements. (a) Except as provided in paragraph (d) of this section,
  no person may operate a civil aircraft without complying with the
  operating limitations specified in the approved Airplane or Rotorcraft
  Flight Manual, markings, and placards, or as otherwise prescribed by
  the certificating authority of the country of registry.


It's a device that makes the throttle harder to move. You need it to keep the engine vibrations from slowly moving the throttle away from where you left it during cruise.


Why are the wingtips of sailplanes painted red?

White is indeed chosen for thermal reasons. Gliders use epoxy resins which cure at room temperature and are then tempered at 60°C. This tempering shifts the glass transition temperature to something close to the tempering temperature, so the structure must not be heated under stress to more than this temperature. To limit heating by solar radiation, black surfaces should be avoided altogether and mostly red, blue or grey is used for markings.

The red wingtips were popular in the 1970s and were meant to improve visual identification when flying in hazy weather and close to clouds. They can be mostly found on gliders of this era. Since structural loads are lowest at the extremities, wing- and fuselage tips can be painted in high-visibility colors.

Schempp-Hirth Cirrus with red wingtips but no markings (picture source). This makes it obvious that this is a British glider.


What are the pros/cons of all-moving rudder?

All-moving control surfaces are like regular surfaces, only that the moveable part extends over 100% of the chord. Since the effectivity of a control surface grows with the square root of the chord fraction $\lambda$ of its moveable part, an all-moving (also called full-flying) control surface has twice the effectivity (defined as normal force change per degree of movement) of one with a 25% chord length of its moveable part.

Effectivity of a control surface over chord fraction $\lambda$

Hermann Glauert was the first to calculate the inviscid lift due to control deflection, and the result of his work is shown above. The truth (as defined by wind tunnel results) is somewhere between his curve and that of my simple approximation.

Control surface in subsonic flow

Deflecting a flap causes the camber of the control surface to change. This is a positive effect in subsonic flow and allows the resulting airfoil to create more lift in the desired direction. Also, the orientation of the leading edge is maintained, causing much smaller suction peaks there than when the full surface is deflected. Suction peaks require a long pressure rise, which promotes flow separation when its gradient is too steep.

Control surface in supersonic flow

In supersonic flow, camber increases wave drag, so the full-flying control surface is more effective. Pure supersonic flow has no suction peaks, and flow separation is less of a concern. Therefore, full-flying surfaces are better for supersonic flight, while hinged surfaces are the better choice in subsonic flow. Especially in transsonic flow, at least a moveable stabilizer is necessary to avoid control reversal due to the contour break of a hinged control surface.

Stealth aircraft

Stealth aircraft benefit from large, coherent surfaces, and the gap of a control hinge will increase their RCS. Even subsonic stealth aircraft like the Lockheed F-117 and the Northrop Tacit Blue use full-flying control surfaces for their ruddervators, as does the supersonic Northrop YF-23.

Why the SR-71 rudders are special

An intake unstart at Mach 3.2 is a violent event, and the SR-71 needed all the yaw control authority available to compensate for the sudden asymmetric loss of thrust. Its rudders were optimized for supersonic use, and the actuator could be driven to its extreme position by an explosive charge which was fired automatically when an intake unstart was detected. To ensure optimum intake operation, the engines were positioned at mid-span, and the yawing moment of thrust changes was much higher than that of conventional fighter aircraft which have their engines close to the centerline for better roll agility. In addition, they use their rudders mostly in subsonic flight; only the size of the vertical tail is determined by yaw stability at top speed.


What does "Last Call" mean on CTAF frequency?

It means they are changing frequency and will not be making any more CTAF calls. As far as I know its not required although something along those lines is pretty common place. Personally I call:

  Departing the pattern to the [north|east|south|west]

Its the self announce version of "frequency change approved"


How is the JFS manual hand pump operated on an F-16?

I used to be a crew chief on F-16s in the Air Force. Our pilots usually jump both bottles at once during a start up to ensure a proper start, if it fails it's most likely because there wasn't enough pressure accumulated. It's part of our launch procedures before they take off to check to see if it's within limits, if not you have to get the "T handle" and go manually pump it up to pressure. This is done in the left hand wheel well there's a big slot for the handle to be inserted and pinned into to keep it in there while you pump. There's a gauge on the opposite side under a quick access panel to check the gauge. Usually if we do have to pump it you'll pump for awhile and take a look at the gauge and keep going back and forth to check it. We rarely hook anything up to automatically charge it, it's manual 9/10. Actually, it usually takes 15 min to charge however some people are slower or even faster, it's more on the person to determine how fast it charges. It's very tiring to do it.


Why is it runway "1" instead of "01" in America?

Indeed USA deviates from ICAO:

5.2.2.4 Zeros are not used to precede single-digit runway markings. An optional configuration of the numeral 1 is available to designate a runway 1 and to prevent confusion with the runway centerline.

Source: USA AIP - GEN 1.7 Differences From ICAO SARPs
5.2.2.4 in ICAO SARPs Annex 14 (Aerodromes) is as follows (emphasis mine):

5.2.2.4 A runway designation marking shall consist of a two-digit number and on parallel runways shall be supplemented with a letter. On a single runway, dual parallel runways and triple parallel runways the two-digit number shall be the whole number nearest the one-tenth of the magnetic North when viewed from the direction of approach. On four or more parallel runways, one set of adjacent runways shall be numbered to the nearest one-tenth magnetic azimuth and the other set of adjacent runways numbered to the next nearest one-tenth of the magnetic azimuth. When the above rule would give a single digit number, it shall be preceded by a zero.

Shall in ICAO legalese denotes a standard.
The aforementioned optional configuration for "1" covers your concern regarding the centerline:

The numeral "1", when used alone, contains a horizontal stroke, as shown, to differentiate it from the runway centerline marking.

Source: FAA AC 150/5340-1
The rationale is not in the AIP; it's not always given. Deviations from SARPs are also very common, that's why there's an AIP section dedicated to them.


How do uncoordinated turns (skid, slip) affect a helicopter's turn radius?

Given your assumptions about bank angle and airspeed and my assumption that coordinated turn is determined by acceleration inside aircraft pointing downward "perpendicular to the floor" (if you mean anything else by coordinated turn, try to be more specific on it), then you have one exact radius for coordinated turn. That one where centrifugal force generated by airspeed and curvature summed with gravity gives vector matching the (fixed) bank angle. If you want local acceleration to point in other direction (making slip or skid), only free variable remaining is turn radius.

So yes, given airspeed and bank angle is constant, turn radius is the parameter determining if turn is coordinated or not.

In a slip the local acceleration in aircraft points toward that side you want to turn (or, in other words, aircraft's floor is banked too much outside the turn). To get this, centrifugal force has to be less compared to coordinated turn (centrifugal force is only quality you allowed to change), so turn radius have to be larger. To get a skid turn radius have to be smaller for the same reason.

Inertial and gravity acceleration as seen and felt inside an aircraft during a turn with bank angle $\alpha$:

where $\vec{g}$ gravity acceleration and $\vec{a_c}$ centrifugal acceleration. Resulting $\vec{a}$ is total acceleration felt by pilot. From basic mechanics $a_c=v^2/r$ where $v$ and $r$ is speed (either TAS or GS, both are the same here) and turn radius respectively. Turn radius for coordinated turn is $\tan\alpha=a_c/g\Rightarrow r_{\rm coord}=v^2/(g\tan\alpha)$. Any smaller radius with the same bank and speed leads to higher $a_c$ and thus skid, larger radius results in slip. Note that this is true for any aircraft, not specific for helicopter.


I am licensed as a Private Pilot, Airplane Multiengine Land, what do I need to do to be able to fly as PIC in a Single Engine Land aircraft?

No, you cannot. Just like an ASEL doesn't give you the ability to fly an AMEL, if you have an AMEL that doesn't give you ASEL privileges.
Adding the ASEL shouldn't be that hard though, especially if you've done a majority of your training in one. You will still need to take a check ride.


Can an aircraft at 10,000 feet have sea level pressure in the cabin?

If you design the aircraft, shouldn't you be answering that question? If it is part of your aircraft's mission to fly at 10.000ft whilst maintaining sea level cabin pressure, then you should design it that way.

Why would it only be possible to pressurize the inside to 8000ft? Not to 9000ft, 7000 ft or any other arbitrary altitude?

Of course the construction of the aircraft needs to be able to withstand the forces caused by pressure difference between the inside of the cabin and the outside. And the pressurization system needs to be able to maintain the pressure at sea level, so compensating for any air leaks in the pressure vessel.

For an initial feasibility study you could look at the pressure difference on the hull when an aircraft is flying at FL430 whilst maintaining cabin pressure at 8.000ft. Note thate the Boeing 787 maintains the cabin altitude at 6.000ft, while operating at 43.000 ft.

Compare that to the pressure difference between 10.000ft and sea level.
Looking at those pressure differences should give you a feeling whether or not it is easy to achieve your objective.


Sorry to be the bearer of bad news. But, you have already asked this question on www.airport-data.com. A quick search in the FAA search database with the tail number or serial number (which can be found using the tail number) shows that it has not legally flown in the US in almost a decade. So, it is either sitting somewhere as a ramp queen, registered overseas, or not in existence any longer.
Try contacting the last person to register it. Otherwise, it would be like trying to find a salvaged car after it has been junked. It will only pop up if it is reregistered. However, you can pay a private firm like a law firm to research the aircraft’s certificate of title (or simply title). It would be like searching a deed.


Learn in-depth about airplane operations

I'm not aware of any official resources which present all that information in a concise way, but to get a general idea of the operation of a modern civil passenger aircraft you can refer to the manuals provided with flight simulation add-ons. As opposed to the standard aircraft contained in most flight simulators, these payware models are very accurate and highly complex.

Next to the complete manuals, each aircraft typically also contains a tutorial flight manual, where all the steps necessary for the operation are shown in detail (100+ pages each). Here are a few examples:

787: http://qualitywingssim.com/files/ultimate_787_collection/docs/QualityWings%20-%20Ultimate%20787%20Collection%20Tutorial.pdf
A320: https://www.aerosoft2.de/downloads/a318-a319/Aerosoft-Airbus-A318-A319-Vol6-StepbyStep-EN.pdf
Some other Boeing aircraft (PMDG): https://www.precisionmanuals.com/pages/downloads/documentation.html

If you're specifically interested in ATC communications, you can for instance refer to the IVAO documentation about IFR phraseology: https://www.ivao.aero/training/documentation/books/DOC_IFR_phraseology.pdf

Remember that these are NOT official documents, so they are not suitable for any real world use. But in my opinion they are the easiest way to get an idea of aircraft operations. At least that's how I learned it! It has helped me a lot in my Aerospace Engineering studies.


Why are some windows in cockpits made openable?

The opening cockpit windows do serve some purpose, like providing an additional means of evacuation during an emergency.* There have been instances where the crew had used the cockpit windows to escape during hijackings.
There are other purposes like assisting in crew inspection, signaling ground crew, additional ventilation, smoke egress etc (It can also be used for throwing things out, though it is not generally recommended). One main reason (atleast in the past) appears to be to improve the pilot visibility in case the windshield becomes opaque, for example.
The windows are not found in all aircraft (for eg. 787 doesn't have it) and are not very easy to open (note that it opens inwards). From USAToday Ask the Captain:

First there is a locking mechanism, then either a crank which moves the entire window assembly including the frame, or a lever with which to move the window assembly. When the window is closed and locked, it is sealed shut. When open, it does not separate from the frame as the window in your car does.

Actually, FAR 25 Section 773- Pilot Compartment View requires cockpit windows to be openable (or some other means to have clear windshield during precipitation) :

(b) Precipitation conditions. For precipitation conditions, the following apply:
(1) The airplane must have a means to maintain a clear portion of the windshield, during precipitation conditions, sufficient for both pilots to have a sufficiently extensive view along the flight path in normal flight attitudes of the airplane.
(3) The first pilot must have a window that—
(i) Is openable under the conditions prescribed in paragraph (b)(1) of this section when the cabin is not pressurized;
(4) The openable window specified in paragraph (b)(3) of this section need not be provided if it is shown that an area of the transparent surface will remain clear sufficient for at least one pilot to land the airplane safely in the event of—
(i) Any system failure or combination of failures which is not extremely improbable, in accordance with § 25.1309, under the precipitation conditions specified in paragraph (b)(1) of this section.
(ii) An encounter with severe hail, birds, or insects.

In a pressurized cabin, providing windows is not a great idea. (In addition to the increased weight), if anyone manages to open the window, it would be a recipe for disaster (depressurization -> oxygen masks -> land).

*Many aircraft have escape ropes mounted in a compartment above the window on each side of the cockpit as in this A320:

Photo source
And a video of it being used.


Why were the specifications of the Pipistrel Panthera downgraded?

This sounds like an overly optimistic marketing department which wanted to make the aircraft look better. Engineering would allow to predict top speed within a few percent, so I would blame neither the simulations nor the engine swap.

The web page for the Panthera lists 155 kts only for the maximum range condition, which makes sense. Propeller aircraft need to fly rather slowly to maximize range. The cruise speed with maximum power is still close to 200 kts.

Please consider that the required engine power of propeller aircraft grows with the third power of flight speed. To give you the 200 kts top speed, the plane would need to run the engine with 215% of the power setting (and fuel flow) needed for 155 kts.

Once you know the installed power, you get reasonably good results just with the zero-lift drag and the propeller efficiency when you use this formula:
$$v = \left(\frac{2\cdot P\cdot \eta_{Prop}}{\rho\cdot F_{ref}\cdot c_{D0}}\right)^{1/3}$$
Nomenclature:
$v\:\:\:\:\:\:\:\:\:\:$ speed in [m/s]
$P\:\:\:\:\:\:\:\:\:\:$installed Power [W]
$\eta_{Prop}\:\:$ Propeller efficiency; use 0.85 if not known
$\rho\:\:\:\:\:\:\:\:\:$ density of air [kg/m³]
$F_{ref}\:\:\:\:$ Reference area for coefficients, usually wing area [m²]
$c_{D0}\:\:\:\:\:$ zero-lift drag coefficient

The zero-lift drag coefficient for small propeller airplanes is around 0.02 to 0.025 if they have a retractable gear. A very well designed airplane might come down to 0.016, but that is already pushing it. To fly fast, a high wing loading is essential, and then the influence of all non-lifting components on the total drag is rather high. A well-designed airfoil might achieve a $c_{D0}$ of 0.0035, but the whole airplane will be closer to 0.02.

Things get even worse when you aim for higher flight Mach numbers. The Dornier 328 turboprop was initially calculated for 320 kts cruise speed, but Marketing felt the need to claim 340 kts. The difference does not sound substantial, but all engineers thought they must be crazy over in Marketing. In the end, the Do-328  needed 30% more installed power to fulfill the promises made by the (rather irresponsible) Marketing department. The increased engine power indirectly caused an accident in flight test when a propeller (with an unchanged, but now too weak propeller mount) broke off in sideslip and cut through 1/3 of the fuselage. Luckily, the aircraft landed without further incident after that ...

(Disclaimer: This is from the back of my head, and I think I remember the facts and figures correctly. If any of you know more, please edit the last paragraph!)


Why do you never see any other planes in the sky whilst flying?

If you're not seeing them, you're not looking.

I see planes all the time when flying commercial.  Obviously, I see them a lot more when close to a major center, and a lot less when in the sparse parts of the Pacific Northwest (Montana, Idaho, Oregon, Washington).

I think spotting them may take some practice. Visually, a plane 10+ miles away is a very small dot, and easily missed.   Try looking for contrails and be sure to look at altitudes above and below you.  Scan the sky in narrow, 10°  concentrated "fields of view" to scan from left-to-right all the way across the sky.


PPL is Private Pilot License

May fly for pleasure or personal business. Private pilots cannot be paid, compensated to fly, or hired by any operator.

CPL is Commercial Pilot License

Can be paid, compensated to fly, or hired by operators and are required to have higher training standards than private or sport pilots.

ATPL is Airline Transport Pilot License

ATPs, as they are called, typically qualify to fly the major airliners. ATPs must qualify with a range of experience and training to be considered for this certificate.
— Wikipedia


Are the details of flight control laws the same for every fly-by-wire Airbus aircraft or are they only the same within the specific family?

From a pilot point of view they are the same, for all families.

Technically, they are differently implemented, from a family to another one, but they are implemented the same way in the same family.

The basic principle for all Airbus FBW are as follows in normal law:

in pitch normal law the side stick send a «load factor» order that would become limited when protections are triggered such as AOA protection.
in roll the side stick gives a «roll rate» that would become limited when protections are triggered such as bank angle exceeding a threshold.
When sensors redundancy is degraded the laws become degraded and we enter alternate laws or direct law.
On ground we are in direct simulated relation ship between the side stick and the related surfaces.

The differences:
They don’t affect the flying technique from the pilot point of view, they concern the protections mostly those that concern the structure of the aircraft for exemple
The Maneuver Load Alleviation function that distributes the loads on the huge wing of the 330, this protection is specific to the 330/340


Can the HAL Lca Tejas perform Pugachev's Cobra maneuver?

No.
With that delta wing shape it will have pitch control problems at higher angles of attack. The Cobra maneuver requires a small pitch-down moment over the post-stall region up to 110° angle of attack. I very much doubt that this wing planform will have such pitch characteristics, and without thrust vector control a docile pitch behavior is a prerequisite for the Cobra maneuver.
In the development of the LCA a high lift coefficient without leading edge devices was the main goal of the wing design. It should be able to operate in the vicinity of flocks of birds - birdstrike is a real risk on many Indian Air Force bases. At the same time, the small aircraft should be able to fly supersonically, which lead to the double-delta wing as the best way to achieve both goals, and poor post-stall pitch response had to be accepted.
When HAL switched from MBB to Dassault for technical support, leading edge devices were added in order to fulfil the take-off and landing requirements. Post-stall flight was not seriously considered at any point in the development.


How do aircraft carriers treat foreign Flight Information Regions?

Sovereign airspace begins at the 12-mile nautical limit.

In international airspace noone can legally interfere with a flight except the authorities of the country in which the aircraft is registered (see What restrictions apply in international airspace?).


Electric Airplane - Hybrid / dual type engines how would that work?

The B-36 Peacemaker had 6 radial engines, driving 6 propellers, AND 4 jet engines in 2 nacelles.  The jet engines were used for takeoff and for "dash" over a target.  The jets were turned off during cruise because they used considerably more fuel than the piston engines.

As such, they HAVE made propeller/jet hybrid aircraft in the past, though not electric.

To answer your questions:

You probably want to feather the propellers and kill the electric motors.  If the props can only drive you to 250 MPH, leaving them windmilling in the slipstream when the jets are running will add drag, which will only serve to hurt your cruise speed and/or increase your fuel consumption.
They only work in conjunction as speed BELOW what your props can drive (eg 250 MPH, in your example).  Beyond that, if it's speed you're after, you're better off without the props.
At speeds above what the props can deliver, they're essentially small windmills.  And not very efficient ones at that.
See 2.

Now, what WOULD be helpful as a "hybrid" aircraft would be a gasoline engine, turning a prop, with an electric motor added between the engine and the prop.  The electric motor could supply extra power during takeoff and function as a generator/dive brake on the prop during descent.  In the event the gasoline engine failed, the prop/electric motor assembly could be declutched from the gasoline engine, providing you with temporary power to maneuver around and land safely.  Gasoline engines in aircraft tend to be very reliable, but when they DO fail during take-off or landing, the most vulnerable parts of the flight, the results tend to be catastrophic.  As such, the gasoline/electric hybrid would be of no use during cruise but it MIGHT improve the safety factor during the most vulnerable parts of the flight.


Could a C-130 Hercules be built using WW2 technology?

It's possible to get something in the vicinity of the C130 during WW2. The C130's predecessor, the Fairchild C123, was powered with two WW2 era P&W R2800 radial engines, each producing 2000 hp. Presumably, the design and number of engines could have been scaled up.

Remember that a defining characteristic of the C130 isn't it's payload, it is the rough field landing capability, which includes STOL. I've been in a C130 when it was practicing short field landing and takeoff, and the experience was... dramatic. When it hit the runway, it really did hit the runway... with a bang.

A piston powered transport with somewhat the same capabilities of the C130 was produced in the 1950's, the Blackburn Beverly, used by the RAF. The Beverly was built with WW2 technology, and was powered by WW2 vintage Bristol Hercules and Centarus radial piston engines.

The Beverly was abandoned in favor of the turboprop Armstrong-Whitworth Argosy, when it became available, just as use of the C123 was phased out as the C130 became available in sufficient numbers. The greater power and substantially lower maintenance requirements of turboprops made them the logical choice when they became available.

Given that the C130 was initially produced with Allison T58 turboprops, at 3500shp, a four R2800 C130 would have had a power deficit. The larger P&W R4360 at 3000 hp could be used, although it was still having development problems during the war.

A WW2 vintage C130 would have had longer takeoff and landing, and a lower payload, due to the lower power available and the heavier weight of the power plants, but it was possible with the technology of that day.

Would it have been produced? Given that WW2 had its own unique requirements, probably not. Aircraft production was centered around warplanes and transports with long range, such as the Douglas C54. By the end of the war, the Allies had prepared field construction down to a fine art and the teams in place to build those fields quickly in both theaters, so the need for a large transport with rough field capability wasn't as evident.

Where the C130 really became valuable is in lower intensity conflicts that followed WW2, where expert runway construction teams aren't available on short notice, and the front lines of combat aren't nearly as well defined.

So, to a degree, the changing nature of armed conflict defined the need for the C130.


Why is stabilizer trim often controlled by electric motor while other surfaces are mostly hydraulically controlled?

Weight, cost, reliability and maintenance.

See ACTUATION SYSTEM DESIGN WITH ELECTRICALLY POWERED ACTUATORS

Safety

See THE A380 FLIGHT CONTROL ELECTROHYDROSTATIC ACTUATORS, ACHIEVEMENTS AND LESSONS LEARNT

  In terms of safety several aspects can be
  highlighted: As far as power source redundancy
  is concerned the number is increased from 3 to 4
  since 2 electrical systems replace 1 hydraulic
  system. Furthermore an additional margin of
  safety results from the introduction of the
  hydraulic/electric dissimilarity in the power
  sources: This provides further protection against
  common failures, such as maintenance errors,
  which may affect all the hydraulic systems,
  whatever their number. Moreover the electrical
  power provides flexibility in routing, resulting
  in an easier segregation of power distribution
  routes against engine burst and other “particular
  risks”, and an isolation and reconfiguration
  capability that hydraulic systems cannot offer.

  The reduction in the total number of hydraulic
  components results in improvements of the
  MTBF and dispatch reliability, by elimination
  of potential leakage sources.

  The elimination of the generation and
  distribution components associated to one of the
  hydraulic systems (pump, reservoir, filters,
  plumbing…) and the replacement of the
  associated hydraulic actuators by electrically
  powered actuators results in weight savings.


Do airline pilots identify failed engines in the same way as light aircraft pilots?

Yes, the dead foot, dead engine does apply (but not as much as you might think), and, yes, airline pilots need to rely on their engine instruments in order to figure out which engine has failed, especially when you're flying a 4-engine aircraft. Actually, and with obvious prejudice, I prefer to say that the Flight Engineer will use the engine instruments to tell the Captain which engine has failed. Couldn't resist that.

Sudden loss of power on 727-100s and 747-100s/-200s is not nearly as noticeable as, say, on a Cessna 310. If you lose the middle engine (#2) on a 727, all you're going to notice is the loss of 1/3 of your power. Even the loss of engines 1 or 3 will not produce much yaw because they're mounted close to the aircraft centerline.

On the transport-category aircraft I flew it was unlikely that your foot would notice an in-flight engine failure because you took your feet off the rudder pedals as soon as you lifted off and didn't put them back on until short final. Adverse yaw was taken care of by the yaw damper.

If the loss of an engine came during descent at flight idle, the pilots might not notice it unless there is an obvious alert of some kind. We had one quit on us descending into Miami once and neither I nor the f.o. noticed it. Our alert was the f.e. saying something like, "We just lost #3." My increased work load consisted of simply saying something like, "See if you can get it running again. If it doesn't light off, forget it."

If you deliberately shut down an engine, you of course know which engine it is. That happened to me once. Again another vote for f.e.s. This one informed me that the oil pressure was dropping and oil temp climbing on one of the engines. He recommended shutting it down, which we did.

Generally speaking, when you lose an engine suddenly without warning when climbing out, I think the thing to remember is to take your time, fly the airplane with the configuration you have, and work the checklist for the situation at hand. That checklist will have procedures to ensure you shut down the engine that has failed, not one that's still operating. In other words, just do what you do in the sim every 6 months.


Why do we not see propellers on swept wings or jet engines on straight wings?

You can find propellers on swept wing aircraft, such as the TU-95, or more recently, the Airbus A400M.

One turbofan powered aircraft that has straight wings is the Cessna Citation

No, it's not common, due largely to the speed at which the aircraft normally operates. Turboprops tend to operate at a lower speed than turbojets or turbofans, where the benefits of swept wings (better performance when approaching Mach 1) aren't evident, while the benefits of straight wings (better performance at lower speeds) comes in handy on the shorter airfields that smaller turboprops operate from. Bump the cruising speed up to Mach .8+, and the swept wing is the optimal design.

In the case of both the TU95 and A400M, they cruise at higher speeds than most turboprop aircraft, hence the employment of a  sweep to the wings.


There is no straight answer as it depends on the individual fastener and specific aircraft in question. Pressurized aircraft create a whole new set of issues.

In some cases you can lose a whole bunch of them and even lose a full panel without issue as was the case on Delta  2412. While in other cases single bolts or fasteners are far more critical. Fasteners on stationary parts wont create the same imbalance issues as say, losing a fastener from a prop spinner or the such. Fasteners coming loose and being ingested into engines or other critical components can be an issue which is similar to the issue with the Concorde incident.


Why is an elliptical wing planform so aerodynamically efficient in layman's terms?

I believe that you misunderstood the answer that was posted.  The local lift coefficient is different from total lift.  In fact the question itself states the lift and drag decrease from root to tip.  If you include the previous two lines by Peter you will get a better context:

  It is both the planform and the circulation distribution. Note that circulation is not lift coefficient but bound vortex intensity. You can interpret it as local lift coefficient times local chord.

The amount of circulation created is related to the total lift.  See the Kutta-Joukowski theorem.  Peter says the circulation distribution is elliptical along the span (decreasing towards the tip) so the lift is not constant along the span of the wing.

A more Layman's way of understanding this: The lift decreases at the tip since the chord length decreases but the local lift coefficient remains the same.  Since the local lift coefficient is related to the local drag coefficient this also means that the local drag coefficient remains the same along the span.  But again because the chord length decreases along the span the total drag actually reduces at the tip of the wing.