What uses for flight did early aviation pioneers envision?

"Airship" originally meant any large aircraft, whether lighter or heavier than air. Ballooning was already a popular sport among the rich when aeroplanes first flew. Most pioneers seem to have taken it for granted that aircraft - both airships and planes - would be used for private and commercial travel as well as warfare. Airmail was perhaps the most discussed niche role. A few might have had other niche purposes in mind but on the whole they were content just to get the thing flying and find a buyer or sponsor. A V Roe built the first plane with an enclosed passenger cabin in 1912, the first year a mail package was delivered by air.

J W Dunne was one of the few influential pioneer aviators from a military background and argued for a variety of specialist types for different military roles. He was also a friend of writer H G Wells. Together they envisaged total war with vast airship fleets capable of wrecking whole civilizations and hoped that the threat of this would put an end to ground warfare as such. When Wells wrote "The War in the Air" (around 1908?), Dunne sent him some of his research materials which found their way into the story.

Rudyard Kipling (of Jungle Book fame), though not an aviator himself, wrote a novel about a commercial transatlantic mail airship, "With the Night Mail" in 1905.


Can an intercepting fighter jet force a small propeller aircraft down without completely destroying it?

An interceptor can gain cooperation from an intercepted aircraft by means of a show of force ie forming up on the target’s 6 and 9 o clock position and attempting to contact them on the emergency radio channel.  If the target remains unresponsive or refuses to comply, a fighter will often cut in front of its flight path in afterburner, causing the target aircraft to be rocked and buffeted in the jet wash.  This is usually enough to get a response from the target aircraft and compliance with the lead fighter’s or ATC’s instruction.

Any kind of intentional damage to the intercepted aircraft would not be done unless deadly force were authorized against the target.  In which case full force ie employment of weapons against the target aircraft to shoot it down would be used.

The video below is a good report on interception procedures against a civilian aircraft.  It was a joint exercise between the civil air patrol and an F-16 ANG unit.


Does a runway have to be closed for not having markings due to resealing work?

Not Necessarily

While some regulations or guidance material may call for some or most runways to be closed during maintenance or construction work, such as marking removal for asphalt reseal, this is certainly not always the case.

If markings are non-standard, faded, or removed, for any reason, the condition should be documented in a Notice to Airman (NOTAM) so that pilots and other interested parties will be aware of the condition and prepared for the non-standard situation.

An example of such a NOTAM includes this one from Randolph AFB (KRND), where some markings on runway 14L/32R are missing dues to removal and repaint during maintenance or construction work.

  RWY 14L/32R SURFACE MARKINGS NON STD ; SOME MARKINGS MISSING DUE  TO
  REMOVAL AND REPAINT.

Note that runway 14L/32R is not closed during this work. However, the parallel runway, 14R/32L, is closed:

  RWY 14R/32L CLOSED


What distinct challenges are faced in taxi operations that aren't found in other phases of flight?

Well in air you don't have to worry about kangaroos in your path or a wheel falling off unnoticed, or people beside a taxiway mistakenly indicating you won't hit a golf cart.  Heaven forbid you accidentally retract the landing gear.

Jokes aisde, taxiing can be a major challenge even for experienced pilots. First off, your traditional warning systems don't work.  You can't check your route using a low or mid-range GPS because they don't have airport taxiway information.  You won't get a "terrain!" warning when you're about to head off the end of a taxiway.

Steering is difficult because the control surfaces are used differently on the ground, especially in a crosswind.  You don't use your ailerons or elevator to control your path; you use them to keep the wings from lifting and to keep you on the ground.  You use the rudder and steerable nose wheel/tail-wheel (if present) to keep you on the right path, with help from the brakes only when necessary.   Those brakes definitely will be necessary in a tail-wheel aircraft with a strong enough crosswind.  If you fail to control the ground path in a tail-wheel aircraft, an unstable and difficult ground loop can develop.

Did wbeard52 mention low visibility? You can technically land a plane in zero visibility if your plane and the airport are properly equipped, but good luck naviagting the taxiways afterwards. A pilot once remarked that "Taxiing at ORD the first time in low visibility conditions is impossible," and another remarked that he was so confused by low visibility he had to have a follow-me truck guide him. [source]

Taxiing can also be confusing in good weather, especially at night.  Sometimes the taxiway letters jump randomly around the alphabet, sometimes markings are obstructed, sometimes there's construction (you don't see construction much in the air!).   The FAA has an entire handbook appendix devoted to avoiding runway incursions that explains these navigational issues.

You also have to be vigilant for obstacles around you (like those kangaroos I mentioned earlier).  In a tail-wheel aircraft with a high nose, for example, it's recommended to zig-zag a little so you can see what's right in front of you.   In aircraft like the B777-300 they actually have camera systems to augment visibility.  (see this question and the FAA's Airplane Flying Handbook ).

You can also look up a list of recent taxiing incidents here


How to calculate the velocity gradient at the wall normal to the wall (Boundary layers)?

In page 72 you'll find the value of µ at standard sea-level temperature...


Is it possible to get access to flight logs of USAAC trainer planes from the 1930s?

For serial number 31-35
 - Pilot seems to be Brookley, Wendell H
 - Homebase seems to have been Wright Field, Dayton, OH

See Link

For serial number 31-85
 - Pilot seems to be Larkin, James D.
 - Homebase seems to have been Boeing Field, Seattle, WA

See Link

It seems that you can order any of these Reports.


Phoenix Area Helicopter ATC: What is "Hee-lah" (Gila?) One, and what is the 101 transition?

The Gila is a river that runs through Arizona, so that may be a visual reporting point for incoming aircraft.


Is there a required check before selling an airliner?

I'm not aware of any such time limit or window requirement related to maintenance programs that apply to the legality of sale transfers, and couldn't find anything myself, so I'll proceed based on the assumption the answer is "no" but would be very pleased if someone who knows can correct the record.

Airliners or aircraft in general are not required to be sold "mechanically fit" like a, car, as a condition of sale, or fit with the last x months or years.  Regardless of who owns it or when it's transferred, it's airworthy and can be flown, or it's not, and can't (except for temporary permit to fly when you want to ferry an airplane from point A to point B, which you would do if you bought an un-airworthy but mechanically fit aircraft and wanted to get it to your own base).

So if an airliner is sold with a D coming up, there's nothing stopping the transfer from one owner to the other, even if it's at its D check interval limit and is grounded until the check is performed.  The new owner can purchase it and apply for a ferry permit, or a short term extension to the D interval (there is usually some latitude allowed for special situations).

If I was buying an airliner that was only a thousand cycles short of a D, well that is maybe 6 months or 8 months of flying or whatever, and I might specify that the seller complete a D check as a condition of sale (as well as incorporation of all outstanding Service Bulletins), or, I allow for the risks in taking it with the unknowns of a major structural inspection coming up with this risk factored into the price (this can be evaluated by analysing how the airplanes of that type are holding up at D check across the fleet - some airplanes already have pretty onerous structural patching requirements by then, imposed by surprise results during fatigue testing).


Well how many people get airsick during each flight and how many of those really vomit? And of those, how many actually use the provided sick bags? I'm not familiar with getting air sick but I'm sure there are not a lot people really using these bags. There is also no legal requirement for having sick bags. It is an item for 'additional passenger comfort'. Ryanair probably thought this way and so they saved some more money.

They also don't hand out sick bags when they are encountering chops but I'm sure they will have one for you if you ask them.


Is there a way to get the original data used to create performance charts?

As others have stated, the data certainly exists but the manufacturers are under no obligation to provide anything more than what's in the manual.

That said, the performance equations are straightforward and with some effort you could build the tables.  What you are proposing exists for most air transport aircraft for their Flight Management Systems.

As a reference, you might check out Getting to Grips with Aircraft Performance.  It's written by Airbus but provides a very good explanation including much of the math.


Why should the ball be centered during steep turns?

Coordinated flight, even in turns, will minimize drag.

Therefore, there is no efficiency gain by uncoordinated flight, in turns or not.

Therefore, rudder input should be as required to center the ball.


Why does this plane have vapor trails coming out of wings?

This are indeed the vortices a wing sheds where lift suddenly drops. That they occur at mid-span and not at the tips is due to flap deflection. They do indeed start at the outer edge of the Fowler flaps. @NilsNielsen explains well why you see a white line at the core of the vortex.

See this photo (source): This is the same thing happening. It is not specific to the 737-800, but to any aircraft with powerful flaps which end at mid-span to make space for the ailerons.


Is there any mechanism in engine mount to prevent shock loads on engine while landing?

"Shock" loads on landing can be transmitted to engine components.  The original poster appears to be asking about turbine engines specifically.  The significance of a hard landing on the engine spools themselves will be shaft flex and case flex, and the possibility of blade rubbing (and erosion).  This is a concern with a hard landing, and something that must be considered.  There are not "shock absorbing" features or capabilities built into bearings in engine spools; these are intended to have minimal friction in rotation, but no concentric movement about their axis.  It is possible in severe turbulence, and in a hard landing, to experience case or blade damage or wear, and there are inspections prescribed for certain components in certain engines to address this.


What is the structure of the crew documentation used in flight for a commercial aircraft?

The documents legally required on-board differ by jurisdiction. I can only speak to the case here in the US which falls under the FAA. If the flight is between two jurisdictions there may be local regulations to comply with at your destination as well. For example if leaving the US all onboard must have their passports as well as any pertinent custom forms.

  What are they used for?

Generally these documents are all used for reference. Here in the US its generally forbidden to read personal material in the cockpit however the pilots are free to read documentation relating to the aircraft and operations. They may chose to use time in flight to read up on things.

These documents also include emergency procedures that the crew may need to use in the event of a failure.

  What are the other major documents necessary to fly?

Aside from what the plane needs the crew must also have current medical certificates and pilots license on their persons.

If we take a look at FAR 121.135

  (a) Except as provided in paragraph (c) of this section, no
  certificate holder may operate an aircraft unless that aircraft—

    (1)
    Is registered as a civil aircraft of the United States and carries an
    appropriate current airworthiness certificate issued under this
    chapter; and

    (2) Is in an airworthy condition and meets the applicable
    airworthiness requirements of this chapter, including those relating
    to identification and equipment.

  (b) A certificate holder may use an
  approved weight and balance control system based on average, assumed,
  or estimated weight to comply with applicable airworthiness
  requirements and operating limitations.

  (c) A certificate holder may
  operate in common carriage, and for the carriage of mail, a civil
  aircraft which is leased or chartered to it without crew and is
  registered in a country which is a party to the Convention on
  International Civil Aviation if—

    (1) The aircraft carries an
    appropriate airworthiness certificate issued by the country of
    registration and meets the registration and identification
    requirements of that country;
    (2) The aircraft is of a type design
    which is approved under a U.S. type certificate and complies with all
    of the requirements of this chapter (14 CFR Chapter 1) that would be
    applicable to that aircraft were it registered in the United States,
    including the requirements which must be met for issuance of a U.S.
    standard airworthiness certificate (including type design conformity,
    condition for safe operation, and the noise, fuel venting, and engine
    emission requirements of this chapter), except that a U.S.
    registration certificate and a U.S. standard airworthiness certificate
    will not be issued for the aircraft;
    (3) The aircraft is operated by
    U.S.-certificated airmen employed by the certificate holder; and (4)
    The certificate holder files a copy of the aircraft lease or charter
    agreement with the FAA Aircraft Registry, Department of
    Transportation, 6400 South MacArthur Boulevard, Oklahoma City, OK
    (Mailing address: P.O. Box 25504, Oklahoma City, OK 73125).

  Do they differ with manufacturers or airlines?

Airlines may publish excess documentation and checklists that meet or exceed the manufacture specifications this some airlines may have slightly varying procedures. Aircraft makers must publish documentation for the aircraft that includes its operational limitations you can find a good chunk of the regulations in the FAR's here. Specifically,

  §23.1581   General.

  (a) Furnishing information. An Airplane Flight Manual must be
  furnished with each airplane, and it must contain the following:

  (1) Information required by §§23.1583 through 23.1589.

  (2) Other information that is necessary for safe operation because of
  design, operating, or handling characteristics.

  (3) Further information necessary to comply with the relevant
  operating rules.

  (b) Approved information. (1) Except as provided in paragraph (b)(2)
  of this section, each part of the Airplane Flight Manual containing
  information prescribed in §§23.1583 through 23.1589 must be approved,
  segregated, identified and clearly distinguished from each unapproved
  part of that Airplane Flight Manual.

  (2) The requirements of paragraph (b)(1) of this section do not apply
  to reciprocating engine-powered airplanes of 6,000 pounds or less
  maximum weight, if the following is met:

  (i) Each part of the Airplane Flight Manual containing information
  prescribed in §23.1583 must be limited to such information, and must
  be approved, identified, and clearly distinguished from each other
  part of the Airplane Flight Manual.

  (ii) The information prescribed in §§23.1585 through 23.1589 must be
  determined in accordance with the applicable requirements of this part
  and presented in its entirety in a manner acceptable to the
  Administrator.

  (3) Each page of the Airplane Flight Manual containing information
  prescribed in this section must be of a type that is not easily
  erased, disfigured, or misplaced, and is capable of being inserted in
  a manual provided by the applicant, or in a folder, or in any other
  permanent binder.

  (c) The units used in the Airplane Flight Manual must be the same as
  those marked on the appropriate instruments and placards.

  (d) All Airplane Flight Manual operational airspeeds, unless otherwise
  specified, must be presented as indicated airspeeds.

  (e) Provision must be made for stowing the Airplane Flight Manual in a
  suitable fixed container which is readily accessible to the pilot.

  (f) Revisions and amendments. Each Airplane Flight Manual (AFM) must
  contain a means for recording the incorporation of revisions and
  amendments.

  Are they available on paper or display?

Depends on the carrier, a great deal of movement to iPads and the such has seen the digitization of many things.


How common is it in current British usage for the angle between the chord line of a wing and the flight path to be called the "angle of incidence"?

From A.C. Kermode; Mechanics of Flight, London, Pitman, 8th Edn, 1972, p.75 (his bold):

"We call the angle between the chord of the aerofoil and the direction of the airflow the angle of attack.
"This angle is often known as the angle of incidence; the term was avoided in early editions of this book because it was apt to be confused with the riggers' angle of incidence, i.e. the angle between the chord of the aerofoil and some fixed datum line in the aeroplane. Now that aircraft are no longer "rigged" (in the old sense) there is no objection to the term angle of incidence; but by the same token there is no objection either to angle of attack, many pilots and others have become accustomed to it; it is almost universally used in America, and so we shall continue to use it in this edition."

And from L.J. Clancy; Aerodynamics, London, Pitman, 1975, p.56:

"The attitude of the aerofoil, as expressed by the angle between the chord line and the free stream velocity vector ... , denoted by $\alpha$, is called the incidence, or angle of attack."

In contrast to Kermode, Clancy goes on to use "incidence" throughout. Note that this contrast appears in technical books from the same publisher, just three years apart. It was, and is, no big deal.
In my experience, anybody with the slightest technical interest in flight is familiar with both usages and they both still get used interchangeably in the UK.
I have not seen a standard symbol for the rigging angle, presumably because it is of irrelevance to the aerodynamicist. It was once, and occasionally still is, alternatively referred to by its French name of décalage.


How to set frequency and distance in ARINC 429?

The first thing you need to understand is that DMEs are not tuned by their actual frequency but by the frequency of the paired VOR/VHF Com, ILS, or MLS frequency.  For the vast majority of operations, this means a VOR or ILS frequency. This frequency as well as mode settings are coded in the Label 035 as shown below:

And the text from reference to Section 4.1.2:

So you wouldn't attempt to tune 1105.5 MHz. First, it's not a valid DME frequency, as DME channels are assigned to whole MHz.  1105 MHz is valid, but would be tuned by the paired frequency of 113.40 or 113.45 MHz (VOR) or 5067.6 or 5067.9 MHz (MLS). You don't need to know the actual DME frequency as the DME knows the pairing and the DME ground stations are charted using the paired frequency. The snapshot above includes an example of coding to different frequencies.

The unit you mention in the comments is a two channel DME.  DMEs are available with up to 5 channels. Tuning of a specific channel is done using bits 11-13 (DIR FREQ 1-5).  Labels are sent sequentially. The DME expects a minimum of 5 labels per second and any one channel label must be received at least once per second.

The DME distance is output on label 202 as an unsigned twos complement fraction as shown in the following from ARINC 709:

There are 16 significant bits. Bit 28 is equal to 256 NM and each successive bit is half the value the previous. (e.g., bit 27 = 128 NM) The LSB is Bit 14 and is approximate 0.008 NM.

The distance and frequency labels are output from the unit in blocks so you can correlate distances to stations.


What dictates the A320's 'emergency ram air inlet' operation?

(wikimedia.org)

You have misinterpreted the text. Given that the DITCHING pb is not pushed, the RAM AIR pb opens the emergency ram inlet.

The differential pressure (DP) being above or below 1 psi is for the outflow valve (not the inlet). If the DP < 1 psi, the outflow valve opens—this is the opposite to the former title (now the first line) of the question.

This serves two purposes:

Clear smoke from the airplane
Bring in fresh air if the packs fail.

When the system operates in this mode, there is no fine tuning for the outflow valve. By testing, they would have figured out with the fixed ~50% open position, any DP above 1 psi results in rapid decompression.

Note: the protection is via a check valve, so no system logic is involved. It's mechanical.


What are the main differences between Flares and Chaff?

Both chaff and flares are defensive countermeasures deployed by military aircraft. The purpose is to confuse radar-guided or infrared-guided anti-aircraft missiles fired so that they can divert.
A good definition about them is here:

Chaff is composed of millions of tiny aluminum or zinc coated fibers stored on-board the aircraft in tubes. When an aircraft is
threatened by radar tracking missiles, chaff is ejected into the
turbulent wake of air behind the plane.
Flares are used to distract heat-seeking missiles. Most are magnesium pellets ejected from tubes to ignite in the wake behind the
aircraft. These flares burn at temperatures above 2,000 degrees
Fahrenheit, hotter than the jet engine nozzles or exhaust and exhibit
large amounts of infrared light.


Why there is no wake turbulence right after touch down or before rotation?

Well there may be vortex formation on the ground under certain conditions, but it doesn't stick around long enough to really be measured or cause trouble.

Any time a wing is producing lift it will generate a wake. This happens even if the wing generates just enough lift to make the aircraft "lighter" but not enough to get it off the ground: Vortices will still start to form at the wingtips, but as they begin their rotation (downward and outward) they will quickly hit the ground and be dispersed.
If the runway were a narrow strip with the wingtips hanging out in free air you would still see vortex formation in these edge cases, but pilots generally don't like to take off on a tightrope.

Airplanes also usually don't stay in that kind of edge case situation where the wing is generating lift but the wheels are still on the ground for very long: Either they're taking off (soon after the wing starts producing some lift it's producing enough lift and the airplane begins flying), or they're landing (within a few seconds after you touch down you've slowed to a point where the wing's lift production, and thus vortex formation, is negligible). Thus for practical purposes of wake turbulence avoidance the wake begins when the airplane rotates, and ends where it touches down.

It's also worth noting that if you happen to be following close enough for the incipient wingtip vortices to cause trouble on the ground you'll probably be experiencing other issues (jet blast, prop blast, etc.) which will remind you that it's prudent to maintain a safe separation distance from other aircraft on the ground.


Why is there a strip of uncontrolled airspace between Russia and Norway?

Details of the No FIR area

The area extends on 175,000 square kilometers:

From ≈70°N (Bodø FIR) to the North Pole.
From 30°E to ≈32°05'E, and to 35°E for a portion east of Svalbard archipelago.

VATSIM Murmansk sectors (ATC simulation). Source

Border dispute

This Barents Sea strip is of major importance, and has been subject to a dispute between Norway and Russia for 44 years. The reasons include:

This area has been the maritime border between East and West blocks during Cold War (the country is neutral, but still a founding member of the NATO).
Norway is a country with many resources coming from the sea (fish, oil, gas), the sea area controlled by the State is six times its land area.
The Barents Sea is a location with multiple oil and gas fields to be exploited. The large Shtokman gas field (label "5" below) discovered in 1988 happens to be in the vicinity, an agreement was signed between Norway and Russian Federation for the development of the field, but only in 2005:

Oil and Gas in the Barents Sea (red dots are gas fields). Source
The area encompasses the most direct potential route between Europe and the Pacific after the ice floe has melt down.

This dispute was closed when a new treaty entered in force on July 2011 with the border crossing the 175,000 square kilometers disputed region in the middle.

(Source: BBC)

While the border is now settled, responsibilities for air traffic control are still to be formally defined by international bodies.

Currently transiting flights have to be authorized by respective authorities before operating in this area, e.g. London-Tokyo flights using Arctica 1 route, noted B483 on first picture. In addition of commercial flights, the Arctic region is highly monitored by manned and unmanned aircraft.

ICAO and Eurocontrol status

ICAO wants to resolve this issue of missing FIR:

  8.1 IATA brought the attention of the Group to a portion of airspace of unassigned responsibility, extending from the North Pole over the
  High Seas between Bodo Oceanic FIR, Sondrestrom FIR and Murmansk
  Oceanic FIR (Appendix E refers). Considering the increase d interest
  of establishing new ATS routes through that airspace, the Group agreed
  on the following Conclusion:

  TRASAS Conclusion 2/4 – Airspace of Unassigned Responsibility over the
  Arctic Ocean
  That the ICAO Secretariat be invited to take the
  necessary actions to resolve the pending issues regarding the portions
  of airspace of unassigned responsibility extending over the High Seas
  between Bodo Oceanic FIR, Sondrestrom FIR and Murmansk Oceanic FIR

Source:
Report of the Second Meeting of the Trans-Regional Airspace and Supporting ATM Systems Steering Group (TRASAS/2) (Bangkok, Thailand, 18-19 March 2008)

There is a proposal under Eurocontrol auspices (proposal 95.012) to close the topic by Summer 2021:

  FIR border realignment Murmansk FIR / Bodø FIR / Norway FIR:

  Objective: To resolve the long-standing issue of the unallocated
  airspace (NO-FIR area) between Murmansk FIR and Bodø FIR / Norway FIR.

Source: European Route Network Improvement Plan 2019-2024

No aeronautical services

Flying in a no FIR area (when such territory is not forbidden to aircraft) means there is no information service provided from the ground. Flight information service consists on informing aircraft about meteorological events, known other aircraft position and intentions and aids availability. Other services are not available either: No alerting (search and rescue) and no ATC. The related airspace belongs to none of A, B, C, ..., G classes.

For those who want to know more about FIR and Oceanic Control Area, see Who manages International Airspace Traffic?

No FIR areas in general

Regarding the existence of "No FIR" areas:

  3) FIRs have not been established for a few areas in the world.
  These are commonly called uncontrolled information regions or “no
  man’s land.” The largest of these areas is in the South Atlantic
  Ocean, annotated as “No FIR.” Flight Information Services (FIS) also
  do not exist in the high altitude structure in other large areas
  (above the top of controlled airspace). Within no man’s land, aircraft
  separation (prevention of collision) is entirely the responsibility of
  the PIC. Advice and information for the safe and efficient conduct of
  flights is not provided from an ATS unit. An ATS unit does not provide
  alerting services related to search and rescue.

Source: FAA 8900.1 - Flight Standards Information Management System - FSIMS (Vol 4-105-C-3)


What's the greatest height at which a bird has collided with an aircraft?

On November, 29 1973 a bird strike occurred at an altitude of 11,300 m over Abidjan. The engine was shutdown during the collision, and was not restarted.

Altitude

  The altitude is that recorded by the pilot shortly after the impact,
  which damaged one of the aircraft’s engines and caused it to be shut
  down. The plane landed safely at Abijan without further incident.

Source

Species

It was determined the bird was a vulture:

  The remains of the vulture consisted of five complete and 15 partial
  feathers from the wings (secondaries, lesser, and underwing coverts),
  tail, neck, and breast. Sufficient details arc apparent in these
  feathers to allow their certain identification as G. rueppellii, using
  comparative material in the U.S. National Museum of Natural History.

Source

Rüppell's vulture is a specie weighting 7 to 9 kg and living 40 to 50 years:

Source.

Record

Wikipedia confirms this is the highest collision recorded in the history of aviation:

  An aircraft over the Ivory Coast collided with a
  Rüppell's vulture at the altitude of 11,300 m (37,100 ft), the current
  record avian height.

Source

Why such altitude for a bird?

This is well above Everest height, why does this bird flies so high, where there are not so many preys, pressure is only 25% of the pressure at ground level and temperature is about -57°C?

  The reason suggested is that thinner air allows faster flight without much
  effort and saves precious energy. Flying at such a great height,
  vultures face almost no physiological problems with regard to
  breathing; they have much more efficient breathing system than other
  living beings, including humans.

  Their flow of blood enables oxygen to be extracted from air, with far
  greater efficiency than any other living being. If the flight is in
  cloudless condition, low temperature at great heights too does not
  bother them.

Source

Birds at high altitude

  The previous record altitude for a bird-aircraft collision was of a
  Mallard (Anus platyrhynchos) at 21,000 ft (Manville, Wilson Bull.,
  75:92, 1963), based on feathers that I identified from the strike.
  That collision occurred between Battle Mountain and Elko, Nevada, on 9
  July 1962.

  Other high-altitude records of birds include:

  sightings of migrating geese at 29,000 ft, over the Himalayas (Griffin,
  Bird Migration, Natural History Press, Garden City, N.Y., 1964), and

  soaring Bearded Vultures (Gypaetus barbatus) at over 24,000 ft.

Source

Vultures are a known threat to aviation, as are other birds flying high:

Images and data taken from Science Focus article

In 2010, in Scotland, a Rüppell's vulture participating to a display was caught in a wind and was lost. Aviation operators had to be notified, in case the vulture was still in the vicinity.

  With a wingspan of 10ft, it could do a lot of damage to a large
  aircraft. But it's also half the size of some of our small training
  aircraft and it could take one of them, or even a helicopter, right
  out.

Source

Damaged compressor after a bird strike (not the involved aircraft):

Source.


What is the correct name for this ILS Indicator?

That image is a basic representation of a course deviation indicator, as mentioned by Steve H. An actual gauge would look like this:

Image Source

In your image, it shows that the aircraft needs to correct to the left and a little upwards, so that it will be on the glideslope as shown here.


Do safety-critical avionics systems run Linux?

None of the avionics systems I've worked on have used Linux or any consumer-type operating system. There are a few main issues.

First is the practical. Most safety-critical avionics involve a control loop and thus have a real-time requirement. That means it's not just important to run a process and get an answer, you need to get the answer within a tightly-controlled time constraint.  Every critical software process on an aircraft is scheduled to ensure that you have a stable control loop.  To do that, you need a real-time OS and Linux isn't one.

Second is the need for certification.  Software used on an aircraft has to be developed to meet the appropriate development assurance level (DAL) for the associated hazard level.  Safety critical systems are required to meet DAL level "A". Any OS you use has to meet the same DAL as the function running on it.  These requirements are defined in RTCA DO-178C. Linux wasn't developed to this standard. There are only a few OS/software development platforms that are capable of being certified. Green Hills, Wind River, and LynxOS are the few systems I'm familiar with that meet the requirements.

There is also one other constraint in that certification requires very stringent version control.  Avionics will exist in the field for many years and any changes to it have to be certified as well.  Generally, there's no valid reason to update the OS on an old unit, and in many cases you couldn't without upgrading hardware (which is a bigger expense no one wants). So in updating an old unit I have to build the 'new' software to run on the whatever version of OS currently exists in the product. That could be a 15 or 20 years old (or older) platform. A rapidly evolving OS such as Linux would have a negative impact on long term product support.


The clearest definition I could find is from an AOPA quiz (of all places):

  The airplane is pitched up into a vertical or near-vertical climb. It
  then pauses, slips downward momentarily (tail first), and then whips
  into a steep, nose-down attitude.

The tail-first slip backwards seems to be the defining characteristic of a whip stall. Interestingly, Whip Stall and Tumble Awareness is included in the FAA's Powered Parachute and Weight Shift Control PTS, but they aren't defined there either.


How does an airline decide on an engine?

I think you are answering your own question. It all boils down to money. Every factor of the aircraft buying process will be driven by money. They are, after all, a business. Some decision driving factors may include:

The acquisition cost.
The operating cost.
Fuel efficiency. Fuel costs the airline money
The reliability. Down time for the aircraft loses the airline money.
The liability. Is it going to breakdown midflight and cause death and lawsuits?
Manufacturer support. Will they get help if problems arise?
Is their an adequate supply chain of parts?
Airline’s specific history with that engine.
Does the airline already have mechanics certified and experienced for that engine?
Do they already have parts and spares of that engine?
It is easier to maintain only one type/model of engine across their fleet than several.
Tax incentives.
National loyalty for some airlines.
Brand loyalty for other airlines.
Kickbacks
TBO. Maintenance costs money.
Core resale value.
Possible advertisement opportunity.
Contractual agreements.
Politics (both internal and external)
Etc.


Are there examples of taildragger autoland systems?

There aren't any tailwheel airplanes with the level of sophistication that would make it even worthwhile doing.

It could be done in theory but would require a much more sophisticated system because taildraggers are considerably more demanding to land and to control on the ground (they are dynamically unstable while rolling on the ground and want to switch ends - try pushing a shopping cart backwards really fast).  There just isn't a market that would even take an interest in developing it.


Why does the NASA GL-10 Greased Lightning run on diesel?

There is a bit of a misnomer here, although the plane runs diesel engines it most likely does not run traditional diesel fuel as you would find at a gas station. Diesel engines can be run on Jet-A which is available far more widely than 100LL at airports outside the US which Ron mentions.

There are even some applications for diesel engines in GA as noted in your linked question the diamond twin star and now the Piper Archer DX have successfully been running diesel engines for some time now.

According to this paper the Cosworth AG engine was considered which the Navy has already been bench testing with JP-5 and JP-8 jet fuel. Presumably the GS motor they chose runs similarly.


Can an instrument procedure be intercepted from the middle and how?

Answer is yes.

FAA

ATC Section 6. Vectoring:

  When vectoring or approving an aircraft to deviate off of a procedure that includes published altitude restrictions, advise the pilot if you intend on clearing the aircraft to resume the procedure.

  PHRASEOLOGY−

    FLY HEADING (degrees), MAINTAIN (altitude), EXPECT TO RESUME (SID, STAR, etc.).

    DEVIATION (restrictions if necessary) APPROVED, MAINTAIN (altitude) EXPECT TO RESUME (SID, STAR, etc.) AT (NAVAID, fix, waypoint).

  NOTE− After a Climb Via or Descend Via clearance has been issued, a vector/deviation off of a SID/STAR cancels the altitude restrictions on the procedure. The aircraft’s Flight Management System (FMS) may be unable to process crossing altitude restrictions once the aircraft leaves the SID/STAR lateral path. Without an assigned altitude, the aircraft’s FMS may revert to leveling off at the altitude set by the pilot, which may be the SID/STAR’s published top or bottom altitude.

    (Position with respect to course/fix along route), RESUME OWN NAVIGATION, FLY HEADING (degrees).

    WHEN ABLE, PROCEED DIRECT (name of fix), RESUME (SID/STAR/transition/procedure).

ICAO

eurocontrol.int quotes ICAO Doc4444, 15th edition 2007:

12.4.1.4

  RESUME OWN NAVIGATION [DIRECT] (significant point) [MAGNETIC TRACK (three digits) DISTANCE (number) KILOMETRES (or MILES)].

12.3.2.1

  JOIN (specify) AT (significant point) AT (level) [AT (time)].

  Example: LGL123 join upper golf 1 at GORLU at FL330 at time three two.


Are the "centerbody", "fan hub frame", and "intermediate case" all the same thing or separate parts?

On Boeing aircraft, the "centerbody" is part of the exhaust system.  It is the inner is the inner part of the exhaust as shown in the picture below (the outer part being called the primary nozzle).  The centerbody is also referred to informally as the "plug".  Since your question seems to be asking about fan and compressor cases, this doesn't seem to fit.  I'm not sure what Airbus or other airframers call this part, so maybe the word "centerbody" is used differently in different contexts.  But for a Boeing airframe, that's the centerbody.

For turbofans which use a "quick engine change" concept, the fan frame actually splits into two pieces.  The "fan hub frame" referred to the inner part.  Hence the word "hub" in the name. I've marked it up in the image below.  This photo also illustrates the concept pretty well.  This shows an engine being assembled.  The outer part of the fan frame (with fan case attached) is on the right, and the fan hub frame (with the rest of the engine core attached) is on the left.  The "fan hub frame" proper is the part just to the right of the yellow tape.

The term "intermediate case" is ambiguous to me.  I could think of two or three different things that that might refer to. On a two spool engine, that probably refers to the booster case, which is usually immediately forward of the fan frame.  But on a three spool engine, it probably refers to the intermediate compressor case, which is usually just aft of the fan frame. Do you have more context?


Can the FAA stop the municipality owned airport from closing down?

Frequently, municipal airports are created and/or operated with funds granted by the Federal Government that contain contractual obligations that the airport remain operating until a particular date or certain conditions.

I don't know about that particular airport.

Even if a municipality owns the airport free-and-clear without contractual obligations to operate it, the FAA does have a lengthy process for shutting down an airport.

Since you're in Wheeling, you may be familiar with Meigs Field, which was abruptly closed against FAA rules, leaving airplanes stranded, charts incorrect, and airplanes attempting to land at an airport that didn't even have a functional runway anymore!


Considering a piston engined aircraft, what resistance pressure would be generated within its engine bay against its cooling intake?

3 main points come to mind:

The space above the cylinders is a pressure plenum so that the air pressure and velocity flowing past the cylinders is the same everywhere.
The space below the cylinders is a low pressure zone and to achieve that the exhaust opening should be larger than the inlet opening(s) to get the highest differential at low speed, but can be reduced as ram pressure increases (hence a cowl flap).  The pressure balance has to take into account air bled off the high pressure plenum to pass through coolers or other services that need ram air.
The baffling that controls the flow between the high pressure plenum above to the low pressure exhaust zone below past the cylinders has be tight to the cylinders, actually touching the fins, so that the cooling air is forced between the fins.  Cooling air that passes beyond the edges of fins does no good.

As for details and numbers, you should probably obtain this book on piston cowling design.


Why does an aircraft use less fuel while landing as opposed to takeoff and climb?

Ground effect plays very little here.

When taking off and climbing you need to add kinetic energy and potential energy to the plane in terms of speed and height. Getting that energy requires burning fuel.

When landing you want to get rid of that energy. Easiest way is to turn down the engine (or off when something breaks) and let drag slow you down and trade height for speed.

When taking off the plane will also be heavier because it will have more fuel on board. So it takes more energy to speed it up and get it up high.

It's very similar to climbing a hill and descending a hill, going up takes energy and going down means you can coast.


When is compressibility a problem for a pitot tube?

In subsonic flow, a pitot tube measures the total pressure $P_{0}$, while a static port measures the static pressure $P$. For very small Mach numbers, we can use the incompressible form of Bernoulli's Equation for determining the speed.

As there is no energy due to compressibility, the density $\rho$ is constant. This means that along a streamline,

$\frac{P}{\rho} + \frac{1}{2} v^{2} + gh = constant$

Neglecting gravity, we have,

$\frac{P}{\rho} + \frac{1}{2} v^{2} = constant$

Using this, we can determine the velocity as

$v = \sqrt{2\frac{P_{0}-P}{\rho}}$

This equation, however does not take the effect of comprehensibility into account. While at low speeds this is not a problem, this causes an error as the Mach number increases above ~0.3. As the speed increases above this value, the term $\frac{1}{2}\rho v^{2}$ no longer gives the difference between the Total and static pressure.

In case of compressible flow, neglecting gravity we have,

$\int_{P_{0}}^{P}\frac{dP}{\rho} + \frac{1}{2} v^{2} = constant$

along the streamline as $\rho$ is no longer constant.

For adiabatically expanding gas, we have,

$\frac{P_{0}}{P} = (1 + \frac{\gamma-1}{2} M^{2})^{\frac{\gamma}{\gamma - 1}}$

where $\gamma$ is the specific heat constant and $M$ is the mach number. In this case, the velocity can be calculated as,

$v = \sqrt{\frac{2 \gamma}{\gamma - 1} \frac{P}{\rho} [\frac{P_{0}}{P}^{\frac{\gamma - 1}{\gamma}}-1]}$

This difference gives rise to the error, which is positive i.e. compressibility error produces ASI readings that are too high. In terms of the pressure ratio, the error is more than 8% as the aircraft approaches transonic speeds. The following image shows the difference in pressure ratio between readings using assumptions of incompressible and compressible flow.

Image from Mechanical Measurements and Metrology - Measurement of Fluid Velocity by S. P. Venkateshan

Basically, the issue is with the assumptions in the method use to calculate the velocity- for low speeds, we assume that the density is constant, which is clearly not the case as the speed increases. Usually, M = 0.3 is taken as the cutoff point.


Where to find historical locations of North Atlantic Tracks?

This guy has a 365 day history online.

You could contact him for older values.

You can also get some history using Archive.org.


How should one fly the entry procedure to an approach when the hold is not aligned with the outbound course?

I flew many of these types of approaches in northern Canada from 1980 to about 1990. In my opinion Option "2" is the best, followed by option 1, but all three are possible.

It is my understanding that when cleared for an approach, you own the airspace, and as long as you stay in the "protected" airspace, you can do almost anything you like.


What is the difference between "flight level" and "altitude"?

Flight levels use QNE or pressure altitude, while altitude references QNH or local pressure adjusted to sea level pressure.  Altitudes are used at low levels and flight levels at higher levels.  The transition between altitudes and flight levels differs by country and is generally just above the highest obstacle in that country.  In the US the transition altitude/level is 18,000' / FL180.  Some countries transition as low as 5000' / FL050 and the transition altitude/level may vary from airport to airport.

In the altitudes knowing accurate elevations relative to the ground and obstacles is important for collision avoidance and this is the reason QNH is used here.  Each airport will report QNH and controllers will issue the current QNH as needed.  You need to know the QNH for obstacle / terrain avoidance but you need to be using the same QNH as those around you for aircraft vertical separation.

Above all terrain/obstacles the only thing we care about is vertical separation, so we no longer need to know about the actual pressure and instead use a standard reference pressure, QNE / 1013.25 hPa / 29.92" Hg.

Note that flight levels drop the last two zeros of the corresponding altitude and so 30,000 is FL300, not FL30000.  When checking in with a controller, FL300 would be pronounced flight level tree zero zero.

It is also worth noting that an altimeter cannot actually determine altitude.  It can only determine pressure (technically local static pressure compared to a reference pressure).  It converts this pressure to an altitude using a calibrated non-linear scale.  To illustrate the point, look at this map of 500 mb heights:

500 mb correlates to 5500 m or 18,000 ft in a standard atmosphere.  In a real atmosphere this height varies and is not actually level.  An airplane flying "level" at FL180 from LAX to NYC last night will have actually descended almost 300 m while indicating a constant altitude.  These deviations in true altitude from indicated altitude are acceptable, however, since they effect everyone equally in the same locality and separation is maintained.


Why is an aircraft carrier's arresting cable made from steel?

The single most important thing for an arrestor cable is that it works reliably, compared to this incremental differences in weight or durability are fairly minor considerations.

One of the major advantages of kevlar is that it has a very high strength to weight ratio, however all this really achieves in this context is that the cable is thinner and lighter and I would guess that the weight of spare arrestor cables is vanishingly trivial in the context of the total payload of an aircraft carrier.

Another consideration is that Kevlar has much lower stiffness than steel, which will be further exacerbated by the differences between a fibre rope and a braided steel cable. This means that it will extend further under the same load. Not only does this mean that it allows the aircraft to travel further before it stops but you also need to fundamentally redesign the whole arrestor system to account for the very different material properties of the wire and then the new design would need to be tested, evaluated and certified.

Also, while kevlar is considered abrasion resistant by the standards of textiles it is nowhere near as resistant to abrasion as high strength steel cable. Consider that industrial steel cables may have a design life in the order of decades (think of suspension bridges) whereas high strength polymer climbing ropes are typically retired after a few years, mostly because of the cumulative effects  of abrasion, dirt and UV exposure. Also steel is almost entirely unaffected by contamination by spilled fuel, solvents, lubricants, hydraulic fluid etc.

Similarly the arrestor hooks on aircraft are made form high strength steel, which is much harder than Kevlar so even a small burr or sharp edge (as you miht get form landing or combat damage) could cut through a kevler rope like knife whereas a steel cable is much more resistant to sharp edged shearing.

125 loading cycles is nowhere near where metal fatigue would be an issue, especially in steel, so it seem more likely that the life of the cable is based on direct wear and local overloading from the arrestor hook. Steel being relatively hard while having reasonable ductility  is much better at tolerating this sort of wear and tear than most other materials.

It's also worth noting that overloading beyond the yield stress (but before total failure)  will often produce  a noticeable kink in a steel cable whcih is a warning sign that it shod be replaced. This gradual failure mode (ie damage is measurable before it becomes critical( is one of the major reasons why steel is preferred for safety critical structures ie you get some waring of impending failure.

However the most compelling answer is that steel cables are proven to work well for the job and so there is no compelling reason to redesign the whole system to use a new material for the sake of fairly marginal (if any) benefits in performance.

It's also worth noting that textiles are use for the arrestor nets for emergency landings where it is known or suspected that the landing gear on a particular aircraft is compromised. Here the light weight and greater stretch is a distinct advantage as it mitigates potential damage to the air-frame.


How does one differentiate a "fly by" from a "fly over" waypoint?

A flyover waypoint will have a circle drawn around it on a chart, whereas a fly-by waypoint will not. (Easy to remember: the circle looks like the O in Over)

The symbols for a fly-by and a flyover waypoint in aeronatutial maps and charts can be differenciated by the circle surrouning flyover waypoints.

https://www.skybrary.aero/index.php/Waypoint


Why there is no online radar coverage of Madagascar?

For services like FlightRadar24 they typically get data in two ways: via volunteers hosting ADS-B receiver stations on the ground, and directly from the ATC radar system in places where that data is readily available.

For the ADS-B equipped aircraft these services would need volunteers in the area of Ivato Airport (FMMI) to host ADS-B receivers. They would almost certainly be happy to have more receivers, and they even offer free "premium" services (and occasionally free receivers) to people who help provide data. If it's legal in your area, and you are willing to run a receiver station you may want to look into it, and this will get you aircraft which are broadcasting ADS-B data (Mode S+ES with GPS position information).

For the aircraft which are not broadcasting ADS-B information (because they lack an appropriate transponder or GPS system) the problem is a little more complicated - the organization that runs ATC in Madagascar would need to set up radar sites (which presumably exist), and make that information publicly available (which may or may not be the case). A system would then need to be developed to allow the online radar services to process that data and make the flight tracks available (subject to whatever delays may be imposed in that process).

As I don't know much (anything really) about the ATC system in Madagascar, so I'm not sure how robust the radar infrastructure is or how open they might be with their data, so I can't really comment on that half of the system.


Light business jets - how many are sold each year?

For the most recent data available, which is in 2017, GAMA reports that 676 business jets sold worldwide. You can see a breakdown by manufacturer here.

Unfortunately, not all manufacturers detail the models sold. Light business jets typically sell in higher volume, due to their lower cost point. A rough estimate of 60% of sales being light jets would give a rough number of ~405 light business jets sold in 2017. There is no way to ensure this is accurate, but it should give you a ballpark number.


Is the gas velocity of a jet engine relative to the engine speed or is it absolute?

The answer is NO, but it is important to understand why. I will explain the conditions, and answer your questions at the end one by one.

First point you are never testing the same engine:

Aircraft manufacturer usually introduces its inlet and its nozzle so both are not usually the same in a test and in the real conditions. (that will mean is partially installed)

You are not including the general effect of the A/C aerodynamics.
You are not including the air bleeding and oil and fuel pump (also, a partially installed engine)

Essentially you are asking about the effects between installed and uninstalled effects on an engine.

Answering your qeustions:

If we measure the absolute inlet and outlet velocities are the same as before or only the relative ones(aircraft velocity+gas velocity) are the same?

This question is not clear as an engine will have different outlet velocities (fan, main cowl...). Taking care about the right reference systems the speed will be of the same order but affected by my previous argument about installed/uninstalled engines

In the case of the engine attached to the aircraft all the fuel energy that can be used is transformed into changes of the kinetic energy of both the aircraft and the air passing through the engine.Right?

Now, some part is used for bleed air, electric systems, fuel and oil pumps. Not all energy is used to cover the drag of the airplane.

In the first case of the test, the kinetic energy of the engine isn't changing, so all the used fuel energy is changing the gas kinetic energy, so in this case the difference in the kinetic energy of the gas is greater. Does this makes sense since we talk for the same operation point?

Given that you establish the reference system fixed to the engine, you will as well not have a difference in speed produced by the engine. Actually you should used that reference system.


What exactly is VMO and how does it affect a plane when it is exceeded?

$V_{MO}$ is a “maximum operating speed”. It is one of many “V-speeds” defined for an aircraft that limit operation at various flight phases. All V-speeds are indicated airspeeds¹.

The $V_{MO}$ is the maximum permitted speed for the aircraft. This includes a safety margin, so pilots can reasonably fly near that speed. Exceeding it is not immediately dangerous, but as it reduces safety margins, is an incident that should be investigated.

There is another speed, $V_{NE}$, the “never exceed speed”, which is somewhat higher and which marks the point where things start to get dangerous. When the aircraft exceeds $V_{NE}$, aeroelastic flutter may develop that will destroy the aircraft and/or important parts may break off as the dynamic pressure becomes higher than what they are designed for.

Also these speeds have their Mach number counterparts², $M_{MO}$ and $M_{NE}$. At high altitude, the same indicated airspeed (IAS) corresponds to much higher true air-speed, since indicated airspeed decreases with pressure, while the same Mach number corresponds to slightly lower true air-speed, since speed of sound only depends on temperature. So at high altitudes, the Mach limits are reached first while at low altitudes the IAS limits are.

Exceeding the $M_{NE}$ has different effect, though also dangerous. Above that speed flow separation occurs above the wing due to supersonic speed of the flow. This leads to loss of lift and significant down-pitching moment (a.k.a mach tuck), which aircraft not designed for supersonic flight may not have enough elevator authority to compensate.

¹ The airspeeds are given as IAS, the speed measured by pitot probes, so they can be directly compared to the indication in cockpit (aircraft with EFIS (“glass cockpit”) usually correct those measurement errors that can be estimated, showing so called calibrated airspeed (CAS)). However it may not be just a simple number but may be tabulated depending on other parameters.

In particular $V_{NE}$ and $V_{MO}$ may depend on altitude, because flutter depends on true airspeed (TAS) and at lower density (due to lower pressure at altitude) the same TAS corresponds to lower EAS/CAS/IAS.

² Mach number is true airspeed as fraction of speed of sound. In this case the limiting factor is formation of shockwaves due to the flow speed locally exceeding speed of sound around some parts of the aircraft.


Where can I find details on the control surfaces of the F-15C?

Aileron: +/- 20 degs

Horz. tail: 26 deg up, 15 deg down

Rudder: +/- 30 degs

See: https://www.nasa.gov/centers/dryden/pdf/87906main_H-1073.pdf


Well I suppose the answer depends on whether or not the flight crew are good dancers: If my uncoordinated self was trying to bust a move in an airline cabin I'd probably wind up kicking someone in the face, but these folks seem to be doing OK.
I can only assume dance lessons are part of SpiceJet's crew training program :-)

Alright, in all seriousness - there is increased risk any time every person onboard isn't securely strapped into their seats. There have been incidents (recent ones) where flight crew walking about the cabin have been injured due to unexpected turbulence, and those same unrestrained people can essentially become human projectiles to injure others onboard.
That said I personally don't think the cabin crew doing a mid-flight dance routine poses a significant safety risk.

The fact that one of the pilots was out of the cockpit recording it is slightly more questionable, and may be what has the DGCA upset in this situation. While there are procedures for having one pilot off the flight deck those provisions are generally for necessary things (like a trip to the bathroom, or investigating a systems fault). The intent is for the cockpit to be manned by two qualified pilots at all times.
If an emergency were to have happened during this dance routine the pilot we see in the video would have had to get back to the cockpit, strap in, and put on a headset (& possibly an oxygen mask) before being of much use.


How can I customize my training to become a flight instructor?

First, if you haven't already go check out AOPA's Let's Go Flying site - specifically their page on how to pick a flight school/instructor. Some of the advice I'm going to give you is pretty much ripped right from them.

For my two cents, if you're going for a career move (even a part-time side job type career), you want to optimize your training path - you do not want to be like me where you're doing this whole aviation thing "just for kicks" and can be be a perpetual student pilot taking as long as you want to get each rating!

Generally speaking this means you want to follow the "traditional" path of certificates and ratings in your chosen aircraft category and class. For Airplanes that would be Private Pilot, Instrument Rating, Commercial Pilot, and CFI.
You probably don't want to "detour" to ratings like Sport Pilot (unless you want to become a sport pilot instructor and don't intend to ever become a "regular" CFI, in which case this path lets you skip the instrument and commercial ratings).

The private->Instrument->Commercial->CFI path is "typical" in my experience, and it generally seems to make sense because the skills you use in each phase naturally build on each other and will help you with the more difficult tasks the next rating will demand.

It's probably also worth spending a little time with the Part 61 requirements for each certificate and rating you intend to pick up and planning ahead -- for example, if you can economize by making sure your instrument rating cross-country flight time requirements also satisfy some or all of the requirements for the Commercial rating you can avoid having to do basically the same flying twice.

As far as where you do your training, a lot of that depends on your personal situation (funding, schedule and personality).  The general rule here is "the more you fly the faster the training goes".  I was a weekend warrior for most of my private training, and between weather delays and extended gaps between lessons it took me a LONG time to get that first ticket - the instrument rating may end up taking just as long!

If you're a good student, can take a substantial block of vacation, and have the money to throw at your training an accelerated/immersive program is often the most cost-effective and shortest route to a given certificate or rating: You are effectively becoming a full-time flight student, flying and studying every day, and when you eat, breathe, and sleep aviation you generally pick things up a lot quicker.
As an added advantage these are often Part 141 programs, which reduces the hour requirements for the certificates and ratings (but even if the training is conducted under Part 61 you're still at an advantage because of the immersive nature of the program).

If becoming a full-time student is not an option for you a structured Part 141 program may still be: Some Part 141 schools have "weekend warrior" programs that follow the same syllabus, and have the same benefit of reducing the hour requirements. The drawback is they're not as "immersive", so information may not sink in as quickly and skills will probably take longer to develop - you'll take longer (and probably spend more money) as a weekend student than you would as a full-time student.

The last option is "regular" Part 61 training, which is what most of the folks I know with day jobs they can't escape from do. This is certainly the most flexible option as you're basically training on your own schedule and program. Good instructors will almost universally still be working from some kind of syllabus to keep your training on-track and moving forward, but there's more freedom to jump around and change up the order of lessons, which is nice if you're getting stuck, or bored, or need to really work on a specific maneuver/concept for a while.
The downside is the same as I already mentioned for "weekend warrior" 141 training: the time between lessons really puts a hurting on your mechanical skill development and knowledge retention, and you'll probably wind up taking longer to finish your training.
There is however no reason you couldn't finish up a Part 61 training program right around the bare minimums for each certificate/rating, assuming you fly frequently and don't hit too many personal stumbling blocks along the way.


Is there a clear or particular pattern in the mistake-making that leads to a landing at the wrong airport?

I've been in the cockpit three times in which we realized we were maneuvering to land at the wrong airport in time to avoid so. All three times were at night; all three in VFR conditions, all three with the incorrect runway having the same directional orientation as the correct runway, all three with those runways being separated by just a few miles, and all three being the first time the pilot flying had been into the intended airport.

If I had to characterize the root cause, I would describe it as tunnel vision so to speak, being so focused on what was seen as being where the pilot(s) wanted to go that they failed to take into account that the conditions warranted looking around to ensure that that was where they really wanted to go.

The first and only time I personally almost made the mistake was in the early 1970s ferrying a Grumman American Traveler from the factory in Savannah home to Oregon. Close to midnight, we were under a low but legal ceiling over Mississippi flat land along a Victor airway westbound, navigating by a VOR just beyond our intended airport. The aircraft did not have DME. The airway passed a bit south of our intended airport. It also passed a bit south of another airport 30 or so nautical east of the intended. Both airports had runway lights, both were north-south runways. I contacted the intended airport tower, reported the (wrong) airport in sight, and was given clearance to land. On final I realized that the lights of the town were in the wrong place in relation to the airport, looked on the sectional along the airway, and realized my mistake.

The second time was in the 1980s. I was the captain of a SA-227 Metroliner with a brand new first officer the flying pilot. The intended airport was an uncontrolled field, weather was clear. I called the airport in sight and asked the f.o. if he had it. He replied that he did. We typically made a right-base entry for the runway off our en route course. At the appropriate time, configured to land, he started to turn toward the runway. However, instead of turning right, he started a left turn. I realized that when he had said he had the airport in sight he was looking at the runway ahead and to our left rather the the correct runway ahead and to our right.

Finally, in the late 1990s I was jumpseating on a UPS 757 (as I remember) into Miami. It was around 04:30 or so, still dark, clear weather, no traffic. Neither the captain or the f.o. had been into Miami (or at least so they said later). The captain called the airport in sight and Miami Approach cleared them for the visual. My first clue that something was wrong was when the captain then told the f.o., who was the flying pilot, that he needed to get down, get configured. I figured, correctly, that they had made the mistake many, many others had made. They has mistaken the Opa Locka airport for the Miami Airport. Both have multiple runways, both the same pattern. As politely as I could I asked them if they could see a small smudge of blue neon around 10 miles in front of the nose. They said they could, and I told them that was the Miami Sofitel which was completely outlined at the time in blue neon and was alongside the runway they would be using.

Experience is the teacher, which is why when going into Hunter Army Airfield in Savannah for the first time and at night but in clear weather, when asked if I had the airport in sight, I asked for the ILS.


What is this helicopter type at a U.S. military base?

In addition to Peter Kämpf's comprehensive answer identifying the helicopter as part of the Mi-17 family, this aircraft is likely to be a Mi-171E, clandestinely operated by the United States government, specifically it is 15-5207. With respect to 15-5207, the pictured aircraft

is a similar colour to 15-5207
has a similar box in front of its engine intakes (possibly for infra-red reduction)
has the same black triangle design around its exhaust
and has a similar proliferation of aerials on its tail boom.

Mi-171E 15-5207 in Springerville AZ, 2016 (source)
15-5207 was photographed at Felker Army Airfield, Virginia USA in December 2017; the orignal picture from Google maps is also Felker (note the provided link does may not show the helicopter depending on where you are). Felker is part of Joint Base Langley–Eustis. This aircraft has been noted at -

Burbank, California 2016
Yuma 2016
Springerville, Arizona 2016
and in 2018 at Opa Locka, Florida.

Understandably, the American military and secret service use of Mi-171E is not widely publicised, although it's known that the CIA has used the Mi-17 in a number of theatres. This particular aircraft carries no identifying markings; it may be connected with the US Army's purchase of 30 Mi-17s in 2013.
The only comment I can find with regard to this particular aircraft is from the Dutch aviation Scramble magazine on social media -

There are rumors that the US Department of Defense are using Russian
build aircraft for Special Forces Operations in areas abroad where no
western type aircraft operate. Evidence of this is very hard to find.
...
It is known that the US Air Force has the 6th Special Operations
Squadron (SOS),based at Hurlburt Field (FL), which is specialized in
Foreign Internal Defense (FID) operations. The primary role of the 6th
SOS is to assess, train, advise and assist foreign aviation forces in
the use of their aircraft, but the squadron also carries out intra
theater support of special operations forces, flying clandestine
night-vision insertion and extraction, air land and air drop resupply
mission with the capability of operating from unimproved runways.

Mi-171E operated by the US Government (source)


How should simulator time be logged in a pilot logbook?

You log simulated instrument time in an FFS, Full Flight Simulator.
The relevant FAR's are 61.4, 61.1(b)6.


Why is there a white line on Russian fighter jets' instrument panel?

I believe it is exactly what your instructor has said - it helps when regaining control of the aircraft during a spin.

The correct procedure for recovering from such a maneuver is to apply rudder in the opposite direction. Then, keeping the control column centered, move it forward (for an upright spin) or backward (for an inverted spin).

The problem is, when you're in a spinning aircraft everything outside is a blur and the G-forces involved can throw off the pilot's perception - this is of course especially true of inexperienced pilots. The white line painted on the control column in your picture was one method for helping the pilot to keep the stick centered. Having something simple to concentrate on helps immensely, and is more intuitive than looking at the yaw indicator.

Source: Flying at the Edge: 20 Years of Front-Line and Display Flying in the Cold War Era,
by Tony Doyle.

Edit: This book is an autobiography of a Cold War era RAF pilot, and while it does directly mention the white line painted in the cockpit, it does so in reference to Vampire and Meteor aircraft. I cannot find any reference specifically to Russian aircraft anywhere in the book, and neither does there appear to be any picture evidence of the stripe in the cockpit of any British aircraft. Perhaps someone else can source more evidence.


What is the purpose of the winglets on the Socata TB-31 Omega vertical stabilizer?

What you observe here are VHF nav antennas for a VOR receiver.  This antenna design is lower drag than wire whip antennas.

The antenna serves no aerodynamic purpose except to minimize its own drag profile.


What is the maximum nose wheel deflection angle?

For the B787, the maximum steering angle is 70°. This information can be found in the Airport Planning Manual:

Source

For the A380, which has also a steerable main landing gear, the nose gear steering limit is the same:

Source

The center of the turn is off center, at the level of the main landing gear. With a multiple-boogie landing gear the main gear slips on the ground, which is not desirable.

This effect also occurs with a single bogie, unless the wheels are steerable. Limiting the steering angle also limits this slippage, and the wear going with it.


How many aircraft types are cabin crew qualified for?

I know very little about this, but in the US the regulations appear to say that cabin crew must be qualified by aircraft type and the details are part of the approved training program for each operator (airline).

In the US, 14 CFR Part 121 governs airline operations, and 121.392 says:

  (a) Any person identified by the certificate holder as a flight
  attendant on an aircraft in operations under this part must be trained
  and qualified in accordance with subparts N and O of this part.

Subparts N and O are far too long to quote here (you can always read them yourself), but 121.421 is probably the most relevant regulation to what you're asking:

  §121.421   Flight attendants: Initial and transition ground training.

  (a) Initial and transition ground training for flight attendants must
  include instruction in at least the following:

  (1) General subjects—

  (i) The authority of the pilot in command;

  (ii) Passenger handling, including the procedures to be followed in
  the case of deranged persons or other persons whose conduct might
  jeopardize safety; and

  (iii) Approved crew resource management initial training.

  (2) For each airplane type—

  (i) A general description of the airplane emphasizing physical
  characteristics that may have a bearing on ditching, evacuation, and
  inflight emergency procedures and on other related duties;

  (ii) The use of both the public address system and the means of
  communicating with other flight crewmembers, including emergency means
  in the case of attempted hijacking or other unusual situations; and

  (iii) Proper use of electrical galley equipment and the controls for
  cabin heat and ventilation.

  (b) Initial and transition ground training for flight attendants must
  include a competence check to determine ability to perform assigned
  duties and responsibilities.

  [...]

I couldn't see any limitation on the number of "airplane types" that a flight attendant can be qualified in, but the training is administered by the airline so if there is a limitation it may set by them rather than by the FAA. 121.427 requires recurrent training (but it doesn't say how often) and I assume that at some point a flight attendant who's qualified on multiple aircraft types could end up spending more time training than actually working on flights. That's unlikely to be something that the airline wants to happen.


Are flight attendants paid in the same way pilots are paid?

It mightn't be a bad idea to specify which country you are talking about, as practices can vary throughout the world, and potentially even amongst individual airlines within the same country.

Last year I looked into becoming a FA for a smaller Australian airline. The pay arrangements were:

A guaranteed minimum annual salary (which was about $45k)
On top of that,  flying wages based on scheduled flight times (4.20 per hour, a bit extra per hour for the hours worked above an agreed number of hours in a month). Note that even if a flight is delayed it is still issued with adjusted scheduled times. The 'padding' applied to regular scheduling works in favour for the employees here.

However, I believe the US  works completely differently. And as I said, this is an example from only one airline.


Diamond DA42 - Do you need the electric master on to extend landing gear?

In general you should always follow the emergency procedures described in your POH.
The emergency procedure for an Electrical Fire in Flight does not ask to extend the landing gear:

EMERGENCY SWITCH . . . . . . . . . . . . . . . . ON, if installed
AVIONIC MASTER . . . . . . . . . . . . . . . . . . . . OFF
ELECT. MASTER . . . . . . . . . . . . . . . . . . . . . OFF
Cabin heat & defrost . . . . . . . . . . . . . . . . . . . OFF
Emergency windows . . . . . . . . . . . . . . . . . . . open if required
Land at the next suitable airfield

CAUTION
Switching OFF the ELECTRIC MASTER will lead to total
failure of all electronic and electric equipment. [...]

(DA-42 POH - Emergency Procedures)
In case of a complete electrical failure, the electrical hydraulic pump will no longer function:

In case of a failure of the electrical pump, which is driving the
landing gear actuators, the landing gear can be extended
manually [...]

Even if there is still pressure left in the system, the gear lever will no longer open the valves without electrical power:

The hydraulic pressure for the landing gear operation is provided by an electrically powered
hydraulic pump, which is activated by a pressure switch, when the required pressure is
too low. Electrically actuated hydraulic valves, which are operated with the gear selector
switch, provide the required hydraulic pressure for the movement of the landing gear.

(DA-42 POH - 7.5 Landing Gear)
The checklist for Complete Failure of the Electrical System says:

NOTE
The landing gear uplock is no longer ensured. The landing
gear may slowly extend.
The landing gear can be extended manually according to
3.6.2 - MANUAL EXTENSION OF THE LANDING GEAR.

So it's possible that the gear will already extend without electrical power, but you can always follow the manual extension procedure.


Is a mode C transponder required underneath Class C airspace?

You are correct. You do not need a transponder to operate under Class C airspace if there are no other overlapping airspace areas where a transponder is required. In fact, if you read a little further in that reg, you'll see that is one of the places where aircraft built with no electrical system are allowed to fly at all!


Does adding flaps during ground roll perform better in short-field takeoff?

I found this answer is a good analysis.

13.3 - Obstructed-Field - Skimming versus Wheelbarrowing or Flap-Popping
"Another possible procedure (which is usually not recommended) is to keep the flaps retracted until you are ready to leave the runway. Less flaps means less incidence. A big disadvantage is that “popping” the flaps like this increases your workload at a time when there are lots of other things you should be attending to. Another disadvantage is that you run the risk of extending the flaps past the takeoff position to the landing position, creating lots of drag, which is really not what you want in this situation. If your POH calls for this procedure, go ahead, but be careful. Make sure you have some sort of detent to block inadvertent over-extension."
-- John S. Denker, See How It Flies


Why are Inline Engines more commonly used than Radial Engines?

The big advantage of radials at the beginning was their large frontal area, which meant they could be air cooled. An inline air cooled engine can run pretty hot on the rear cylinder. The bigger the engine, the more of an issue cooling becomes. There are some huge air cooled radials, in sizes that would be unthinkable for an air cooled inline engine.

As technology advanced, more complex water cooled engines became more popular. However air cooling was still a big advantage in military planes, due to the absence of a delicate cooling system that could be damaged, enabling radials to persist in this arena. Of course these days no-one would dream of putting a piston engine in a fighter.

Nowadays liquid cooling is almost universal for piston engines in general applications, with small aircraft being one of the few areas where air cooling has managed to hold out to some extent (see below.) In the absence of a military application that prefers air cooling, the large frontal area has become the radial engine's downfall, due to the large aerodynamic drag it produces. The other problem is that the valve gear is quite complicated, which means overhead camshafts and multiple inlet/exhaust valves per cylinder are impractical. This makes efficiency vs power to weight ratio a big issue as follows:

For an engine to have good power to weight ratio it must run at high RPM. To run at high RPM it must breathe effectively. To do this with just two valves they have to open wide. To stop them colliding with the piston, the compression ratio must be low, which limits efficiency. Hence most modern engines have more than two valves per cylinder to get around this problem.

Further reading

Pratt & Whitney R-2800: 46L displacement, over 2000hp from an air cooled engine, by no means the biggest!

Excellent animation of the valve gear, which also tends to illustrate the difficulty of putting more than 2 valves on a cylinder. Also, lots of history (obviously.)

In World War II both Double Wasps (46L air cooled radial) and Merlins (27L water cooled V, licensed from Rolls Royce in Britain and built locally by Packard) were used by the American military. I once read a very good authentic World War II discussion about the tactics of when to use air cooled radial fighters and when to use water cooled ones. Unfortunately I can't find it. Here's one of the many discussions on the subject. Note that the Merlin had overhead camshafts and 4 valves per cylinder, like modern engines, whereas the Double Wasp obviously did not.

Modern air cooled engines

I am more of an engine guy than a plane guy, but I've just been looking at modern air cooled aviation engines. They are only available in much smaller sizes than typical WWII fighter engines. Typically they have 4-6 cylinders, too few for a radial, but enough to cause cooling problems on the rear cylinder in an inline.

The compromise is a flat (boxer) engine with 2 or 3 cylinders on each side. This also overcomes two other problems with radials: upper cylinders obstructing pilot view and oil collecting in the lower cylinder when stopped. You also have at least one of these problems with an inline, depending if you mount it upright or inverted.

Small aero engines can be either water cooled or air cooled. The designer has to ask: given the issue of reliability in aviation, does the weekend pilot really want an engine as complicated as the one in his car, with water cooling, cambelts and engine management, all of which could go wrong?

The air cooled engines I've seen (Lycoming) do only have two valves per cylinder, all driven from a common camshaft. (A simpler choice than the cam ring on a radial) I haven't seen an air cooled flat engine with overhead cams and multiple valves per cylinder, but it would be easier achieve than doing the same thing on a radial.


Why do most single propellers have a clockwise rotation?

I wasn't able to find any good historical references, so this answer is pure opinion.  (sorry).  I'll break this down into two separate questions.

Is there any reason for single-engine propellers to turn the same way?

Yes.  When flying, the spin direction of the prop has several effects.  Helical prop wash, p-factor, gyroscopic precession, differing blade angles of attack all are due to the asymmetry of spinning in a single direction.  An experienced pilot will want to understand and compensate for these effects when necessary.  It is easy to see that once this is understood, a single configuration will be preferred within a community to minimize differences between aircraft.

Is there any reason to prefer CW rotation over CCW as a convention in a single engine plane?

None that I am aware of.  It appears to be simply an accident of choice.  I had wondered if the majority of engines available to early manufacturers was in that direction and made it preferable, but I couldn't find anything suggesting that.  Indeed today the majority of automobile engines rotate the opposite direction.  Making (piston) engines rotate the other direction is not a huge problem.  Twin-engined aircraft and watercraft often have counterrotating engines and propellers.


How do I mount an iPhone X in the cockpit to record flights, as a student pilot?

if you were using one aircraft you could get an adhesive mount and then buy a mount that has the adhesive side and a phone mount, but since that is not the case you could try using a suction cup. i have done it a few times, it worked out OK for me.


What are the most powerful airplanes that ever flew?

Most thrust overall?

Well the most powerful aviation gas turbine to date is the GE90-115B, producing a whopping 115,000 lbs of thrust per engine at maximum static thrust settings.

Overall the aircraft with the greatest thrust to date has been the StratoLaunch.  With 6 PW5406 engines, each rated at 56,000 lbs of thrust, this gives it the highest takeoff thrust at slightly over 340,000 lbs.  For production aircraft, it’s the A380.  With 4 84,000 lb thrust class Trent 900s, it gave the jet a massive 336,000 lbs of thrust on takeoff.  This beats out even the AN-225 Myria, with its 6 Progress 6DT engines rated at 51,600 lbs each.

The most powerful turboprop still goes to the old dog - The Tu95 Bear.  With four Kuznetsov NK-12 turboprop engines, each rated at 15,000 shp, no other turbopropeller came close.

The honor for the highest powered piston driven aircraft goes to the Hughes H-4 Hercules.  The ‘Spruce Goose’ was driven by 8 Pratt & Whitney R-4350 Wasp Major engines at 3000 bhp, giving it 24,000 bhp at full throttle.  This is also a sobering demonstration of the huge power to weight advantage of gas turbines over reciprocating engines.  Consider that the Tu-95 mentioned above has half the number of engines yet still packs 2.5x the power of the Spruce Goose at full throttle.

The gas turbine powered airplane with highest thrust to weight ratio that I ever heard of was a stripped down Su-27 used by the Soviets in the 1980s for setting time to climb records, similar to the F-15 Streak Eagle program.  The plane had a thrust to weight ratio of nearly 2:1 and had to be held back by steel cables during run up to full power as its own brakes were insufficient to restrain it.

But the X-15 beat them all.  With a gross weight of 27,000 lbs and a Reaction Motors XLR99 Rocket Engine to give it a push at 70,000 lbs of thrust, it claimed a thrust to weight ratio of nearly 2.6:1!

Who knows?  Maybe there’s an Aurora driver at Area 51 reading this right now who’s getting quite a chuckle out of it as he knows something I don’t!


Does ground speed represent the horizontal speed measured at sea level?

(Source)
Ground speed
Ground speed equipment on-board aircraft measure the speed against the ground. Except in the case shown above where distance information is derived from a ground station (DME station).
Curvature
Ground speed is not derived from true airspeed. When using GPS, or an inertial navigation system to measure the ground speed, it will be the speed across the ground. It is the rate of change of the latitude and longitude, so you don't need to include the curvature.
Once an aircraft (or crew) know the ground speed and TAS, the wind information is then known (how fast the mass of air the aircraft is in is moving).
True airspeed
True airspeed is the speed inside a mass of air. In a zoom climb in an F-15, TAS will be pointing almost the same direction as the [upward] nose of the F-15.
If the mass of air is moving due to head- or tail-wind, then this wind speed is subtracted from (or added to) the horizontal TAS to get the ground speed. (But again, this is not how ground speed is calculated, because there is no direct measurement for the horizontal TAS.)
Vertical speed is how fast the plane is climbing/descending. It's measured by sensing the rate of change of the static air pressure.
RE: edit

I'm simulating aircraft movement along a straight trajectory by constant speed.

This is not how airplanes fly in real life. But for the sake of your model, and if you don't have wind simulation, then the known green distance and the time it takes to move from A to B will do just fine to compute the ground speed.


What is the strange object on 737-800 exterior, on the aft right side?

It's the air inlet for the Auxiliary Power Unit (APU).

Slide 18 here has an image labelled "APU Air Inlet door with Vortex Generator". The inset image on the slide looks almost exactly like your posted image.

I found a much better image here, captioned "Boeing 737-800 with APU inlet".

There is some discussion about why the 737 has vortex generators for the APU on this thread on PPRuNe.


How is fuel drawn from drop tanks in WW2 airplanes?

Like the F-86, air is supplied into the tank so the fuel can be pushed up. On the P-51, the source of the air was the vacuum pump (the one used for the flight instruments), providing 5 psi of pressure.
Knowing this, the two connectors, pressure and fuel, can be seen in many photos.

Source: P-51 manual

And the two connectors:

Source: ww2aircraft.net


Is pilot alerted of any physical or structural failures?

At the risk of sounding like a smartass, the alert is generally in the form of a loud BANG! or CRACK! followed, at best by different handling characteristics and increased wind noise/vibration, at worse, departure from controlled flight.


Are radio channels used by airliners half-duplex channels?

They are half-duplex because all parties share the same frequency. Only one party can transmit at any time.

Full duplex would require two frequencies and therefore third parties would have to monitor both frequencies simultaneously in order to hear both sides of the conversation. Half-duplex operation on a single frequency is inherently 'open-channel' - everybody can hear everything transmitted by anybody else on that frequency. That's the way it's always been done in aviation and in many other fields.

(Answer taken from comments by https://aviation.stackexchange.com/users/13124/transistor and https://aviation.stackexchange.com/users/15152/fiddlesticks)


What is the major source of engine noise for non-propeller aircraft?

At full power it is the mixing process of the fast exhaust flow with the surrounding air. Note that noise increases with the sixth to eighth power of jet velocity, so the loudest engines are those with a low bypass ratio  and reheat on.

Diagram from a Stanford web page on noise. The jet velocity is in ft/s.

At idle the biggest noise source of the whole aircraft is the flow around the lowered landing gear, gear cavities and the slotted flaps that you asked us to disregard. The engine noise is a combination of intake noise, bearing noise and nozzle noise, and which of those contributes most to the engine noise depends on the individual engine and its installation into the aircraft.


Can some planes turn using just the rudder or without banking?

Yes it is possible to turn without ailerons. It is not recommended though.
I have tried it on Cessna 172 as practice many times. I started practicing this maneuver some years ago after I witnessed a disabled Cessna with its ailerons jammed at an angle keeping it in perpetual turn was safely flown back to Van Nuys airport by an experienced instructor on the right seat. when you apply say left rudder the plane will bank left and turn left but you have to control the turn rate by power and rudder. The rate at which one applies the rudder is important; also you should be aware and anticipate potential risk of rolling.
Again it is not recommended but in case of emergency it could save the day!


What is fuel consumption of an A330 during climb and descent?

Descent tables

Climb tables

These tables are for the A330-200 and A330-300: in the footer of the page you can see for which engine these are. What you missed to indicate is the thrust setting, atmospheric conditions and weight to be able to give a realistic answer.


What features are cursor controlled on the A380 Navigation Display?

This is what the KCCU looks like:

Source: A380-800 Flight Deck and Systems Briefing for Pilots

Each KCCU is connected to its FMS:

Source: A380-800 Flight Deck and Systems Briefing for Pilots

From the Airbus booklet cited above:

  The flight crew uses the KCCU to:
     • Navigate through the FMS pages on the MFD
     • Enter and modify data on the MFD
     • Perform some flight plan revisions on the lateral ND.

And:

  The KCCUs enable the flight crew to directly interact with the onside
  ND, MFD and the mailbox section of the SD.

The KCCU can be used, for instance:

  To select an airport
  To navigate throughout the Airport Moving Map (drag technique)
  To set some marks (flags and crosses) for drawing a path
  To activate the correct database.

(source: Getting to grip with surveillance

This figure shows what is reachable with the KCCU:

Source: A380-800 Flight Deck and Systems Briefing for Pilots

As there are two KCCU:

  Each KCCU displays a different cursor. If both cursors are displayed
  on the SD, only one can be active.

There is a functional redundancy between the keyboard and the cursor control unit.

The Onboard Airport Navigation System which displays a moving airport navigation map, is also accessible using the KCCU interactively.

You may also have a look at the book Introduction to Avionics Systems:

  The Multi-Function Display (MFD) displays textual data; over 50 FMS
  pages provide information on the flight plan, aircraft position and
  flight performance. The MFD is interactive; the flight crew can
  navigate through the pages and can consult, enter or modify the data
  via the Keyboard and Cursor Control Unit (KCCU).

  The Keyboard and
  Cursor Control Unit (KCCU) enables the flight crew to navigate through
  the FMS pages on the MFD and enter and modify data on the MFD, as
  mentioned above, and can also perform some flight plan revisions on
  the lateral Navigation Display (ND).


What does "stuff it in the back right corner" mean?

As far as I know, it isn't a standard aviation term, it's just a casual phrase that he's using to emphasize or remind himself about the stick movement he needs. It's like your instructor telling you to "get dancing" on the rudder pedals: it's not an aviation term as such, but it's a very clear, descriptive reminder.

In a three-point landing you pull the stick all the way back after touchdown to keep the tail down. That helps to prevent unwanted pitch movements and gets weight on the tailwheel to help with directional control on the ground (as airspeed decreases and the rudder loses authority). Deflecting the stick to the right would be because of a crosswind from the right. Put those two things together, and the required stick movement is back and to the right, which is one "corner" of the range of motion it has.


Is a trimmed flight not always an unstable system?

But assume, there comes a wind gust, and the angle of attack will
increase. This causes the center of pressure to move forward in front
of my gravity location. So the aircraft will become instable because
the angle of attack will further increase (nose up). The only thing
the pilot could do is to use the elevator to trim in pitch.

This is not accurate.  Are you familiar with "free-flight" model airplanes?  Some of them are stable enough to be flown in the middle of the afternoon when the atmosphere is full of thermal updrafts and downdrafts, with no input from a pilot whatsoever, and no automatic control system (autopilot etc).
You are correct that if some disturbance increases the angle-of-attack of the wing, with a conventional airfoil with no "reflex", the center of lift and center of pressure of the wing will move forward, which is destabilizing.
But the tail is also seeing an increase in angle-of-attack, or if the tail is set to fly at a negative angle-of-attack in normal flight, then the angle-of-attack of the tail becomes either less negative or somewhat positive due to the disturbance.  Regardless of which of these is the case in any given instance, the change in angle-of-attack of the tail, which is far from the CG and therefore exerts lots of leverage, causes the center of lift and center of pressure of the whole aircraft to move aft of the CG.  So the aircraft noses down to a lower angle-of-attack, where the center of lift and center of pressure are again co-located with the CG.  That's how pitch stability works.
For more, see this section of John Denker's "See How It Flies" website.
Note-- for simplicity, I'm assuming that the only forces we need to consider are the "upward" or "downward" ones.  I.e., that the "center of lift" and the "center of pressure" are one and the same.  This is not exactly true.  For example, if the thrust line were way above the CG, then it would still be true that the center of pressure (including the effect of the thrust vector) was co-located with the CG when the aircraft was at equilibrium, but the center of lift would have to be a bit ahead of the CG.  If you find this simplification to be objectionable, then just (mentally) strike out "center of lift" from my answer and just leave "center of pressure".
In my answer here, I'm assuming that some sort of disturbance, such as a sudden updraft, has increased the angle-of-attack of the aircraft.  However, there's actually an additional question embedded in your question, which is "will a purely horizontal gust of wind cause a change in the angle-of-attack of an aircraft that is flying horizontally?"  That's a whole other "can of worms" that we may not really need to get into right now, but let's at least "lift the lid" and take a peek.  The answer to that appears to be that the sequence of events is as follows:  gust of wind from front -> increased lift -> upward curvature of flight path (which may temporarily decrease the angle-of-attack slightly) -> nose-up change in pitch attitude to conform to new direction of flight path -> continued upward curvature of flight path and continued nose-up pitch rotation.  All assuming that the aircraft has not yet come to equilibrium with the new velocity of the surrounding airmass at any given point in the chain of events.  It's not obvious that the angle-of-attack is ever increased above the original angle-of-attack.


How is proper CG maintained in ultralight pusher aircraft?

Usually with suitably-placed counterweights. I used to fly a two-place pusher Chickinox kot-kot that, to be flown alone, needed a lead counterweight of about 15kg fastened on the extreme nose.


MD81: Why are there so many lights on the fuselage?

I think they are reflection from some light posts in the background environment (green line above the blue "horizon" light), and the reflection of the wingtip position light.


Are there (ideas for) GNSS based attitude indicators?

I suppose you could but what benefit wound a GNSS based system offer over traditional gyroscopic and AHARS based attitudes systems while offering better redundancy against a system reliant on outside radio sources and risks with system outages, etc?