Does holding an MEI entitle you to instruct in ASEL/ASES as well?

No. See FAR 61.195 (b):

Aircraft Ratings. A flight instructor may not conduct flight training in any aircraft for which the flight instructor does not hold:
(1) A pilot certificate and flight instructor certificate with the applicable category and class rating...

Without an Airplane - Single Engine rating on the flight instructor certificate, an instructor may not conduct flight training in a single-engine airplane.
As an aside, a CFI/I/MEI needs only a third class medical. See FAR 61.23(a)(3)(iv):

(3) [A person] must hold at least a third-class medical certificate— ...
(iv) When exercising the privileges of a flight instructor certificate and acting as the pilot in command;
(v) When exercising the privileges of a flight certificate and serving as a required pilot flight crewmember

In addition, note that these requirements are for an instructor also acting as a PIC or required pilot. When the student is the only required crewmember for a given flight, the instructor is not required to hold a medical certificate at all.


I’ve done one of these before (not with that company). It literally used the Microsoft FSX game engine but with an A320 cockpit. You have an instructor guiding you and I got to fly around my local airport, land at Kai Tak at night (nailed my first attempt), and because I was in real-world training at the time I shot an ILS approach in zero visibility (definitely did not nail that one).

These simulators are usually aimed at people with little to no piloting experience who want some fun (and they are, I enjoyed mine and my dad has done it 3 or 4 times). If you’ve used FSX you know that you can adjust the realism settings to make it easier to fly so, with help from the instructor a novice can probably land it. At the very least you will learn about basic procedures, flaps etc, and what the cockpit looks like.

It will definitely not make you ready to land the real thing though. These things are designed for fun, not realism.


Why is this F/A-18 flying through a hailstorm of sparkles?

The sparks in the video come from the F-18's Vulcan cannon being fired at night.
During daytime you'd only see muzzle flash accompanied by a pretty puff of smoke. Low light conditions bring out the sparks, or rather, residual gunpowder still burning (or glowing) as it exits the barrel.


What are the benefits of mounting an engine above the fuselage?

It's strictly to stay clear of spray in seaplanes, or because the engine was tacked on as an afterthought for some reason (like a motorglider conversion) and that was the only place to put it.
There aren't any aerodynamic benefits, or you would see the configuration on landplanes.
You've increased the frontal area by having a big pod sticking out.  The high thrust line wants to pitch the airplane over, increasing tail trimming forces required to compensate, and hence drag. There there are the undesirable handling qualities, mainly a strong pitch down tendency when you add power quickly, and worse, a pitch up tendency when you remove power quickly, which can get the unawares into quite a lot of trouble.
So to summarize, sticking an engine there is only done when there's nowhere else to put it.


Are modern fighter jets allowed to fly with an inoperative ejection seat?

Summary
If the ejection seat is inoperable on a US military aircraft, the aircraft will be grounded 100% of the time.  I'm sure you could come up with some weird hypothetical "end-of-the-world" scenario where you'd still take off, but that isn't reality today.
F/A 18 E/F Checklist Procedures
Interior Checklist
After strapping into the jet, the ejection seat is the first thing you check:

Leads, leg restraints, and harness - SECURE/ADJUST
Ejection control handle - CLEAR
Ejection control handle pin - VERIFY REMOVED

There's no point in removing the pin and checking the handle if you do not intend to arm the seats.  This is further confirmed later in the checklist.
Before Takeoff Checklist

[...]
Harness - ATTACHED 8 POINTS
[...]
Seats - ARMED IN THE FRONT
(2 seater) EJECT SEL - ARMED, AFT INITIATE

If the seats aren't armed, then the jet is never leaving the ground.  It is potentially suicidal for fighter aircraft to takeoff without ejection seats.  Fighters don't glide well (they fly to the scene of the crash), they can't fly in a total electrical failure, some can't fly without computer guidance, they can't fly with hydraulic failures, and they fly in very adverse flight conditions.  There are a lot of things, that if totally failed, would turn a fighter into a flying coffin, sans ejection seat.  Fortunately these systems are very redundant, but its usually not worth staking your life on it.


How are NATs connected to European Airways?

There is no equivalent in Europe to the North Atlantic Routes, you simply file direct from point to point.
This is the routing for a flight on Wednesday 18th of January, 2017 (DAL4).

KJFK
MERIT HFD PUT WITCH ALLEX N263A JOOPY NATS RESNO NATS NETKI NIBOG REMSI UL603 SOGPO UT149 OTSOP T149 LIPMI T150 ROLIS
EDDF

You see that the route terminates NAT S at NETKI NIBOG REMSI which are directs, until the flight joins the upper airway UL603 at REMSI.

Here is the routing in SkyVector.

And here is the screenshot from the FlightAware flight.

(Image Source: FlightAware)


Which languages are EASA exams and other documents available in?

This post is an answer to the original question:

  Which is EASA official language? English or all European Union Languages?

EASA communicates in English. They facilitate the translation of regulations to all member languages, but ultimately these translations are not within their domain of responsibility.

Therefore the official language appears to be English only.

See https://www.easa.europa.eu/the-agency/faqs/regulations:

  Implementing Rules are available in all of the national languages of the EASA Member States. How is the quality of these translations assured? Who is responsible for the translations?

  EASA is committed to facilitating the production of good quality translations. To ensure this and, where necessary, to improve, EASA has set up a Translation Working Group in 2008. This Working Group is made up of members of the National Aviation Authorities (NAAs), the Translation Centre of the EU Bodies (CdT), as well as EASA staff members. Also, EASA in cooperation with NAAs and CdT, is developing glossaries in the different aviation domains, such as Air Operations or Air Traffic Management, to enhance the quality of translations. The Member States also contribute to this project in order to capitalise on existing material and experience.

  The final responsibility for translations lies with the EU Commission. The correction of translation mistakes of the Implementing Rules follows the same formal procedure as for their adoption: 1. preparation of the proposal, 2. interservice consultation, 3. committee, 4. scrutiny of European Parliament and of European Council, and 5. adoption. For minor mistakes, the procedure may be shorter. In any case, the linguistic changes will have to be agreed by the Commission’s translation services. These linguistic services will check that no substantial change is introduced, that the term used is acceptable according to an internal translation code or that the same change is included in all linguistic versions.

And here https://www.easa.europa.eu/the-agency/faqs/recruitment:

  What language should I use in my application for a post at the Agency?

  Applicants may use any of the official languages of the European Union when applying for a post advertised by the Agency. However, in order to speed up the selection process and to reduce the amount of the translations needed, applicants are invited to use English. Nevertheless, applicants will not be disadvantaged in any way even if they use other official languages of the European Union.

  [...]

  What language should I use in my application for a traineeship/study placement at the Agency?

  A very good knowledge of the English language is an essential requirement to do a traineeship/study placement at EASA. Applications must therefore be submitted in English. For the same reason, the documents concerning traineeships and study placements at EASA are only available in English.


How are forward and aft CG limits calculated?

You have done half of the way. Since you have computed the CG variations in all loading scenario, you know approximate limits. This limits are the ideal limit from loading and unloading point-of-view. But in real application, the design of the aircraft does not allow such broad limits.

There are many factors that limits the aircraft aft CG movement:

MLG load: The loads on MLG increases as the aircraft weight is increased or the CG is moved aft. Since in most of cases, the MLG's are designed for touch down loads at maximum landing weight, which is lower that the maximum ramp/take-off weight, the static loads at maximum ramp weight may exceed the dynamics load at touch down. So, a limitation may be imposed on aft CG location regarding this issue.
Take-off Tip-Up: At the take-off conditions, the engines are producing their maximum thrust. If the engines are located below the CG, which is the case for under-wing mounted engines, this thrust produces pitch-up moment. This pitch-up moment reduces the load on the NLG. From the other hand, as the aircraft weight decreases combined with aft cg movements, the load on the NLG will be further decreased. At light enough NLG loads, steering effectiveness is reduced, and eventually, the NLG load can become negative causing the airplane to tip up. So an aft CG limits may be imposed to maintain enough loads on the NLG.
Static Stability: Too far aft CG may cause neutral or negative stability, so a margin (normally 10% of MAC) should be provided between the CG and the aerodynamic center.
Go-Around: At go-around condition, the engines are producing the maximum thrust, and a huge pitch-up moment. Elevator deflection are required to counter this moment with pitch down moment. This moment is proportional to amount of upward acting load on the tail a the arm of this acting load. The distance between the tail and the CG is the arm. As the cg moves aft, if the tail reaches its maximum lift the aircraft can not maintain its path. So a limit may be imposed to prevent pitch-up at go-around.

By combining the above limits, and other limits that may arise from that specific configuration, an aft CG limit can be estimated.


How can an aircraft travel faster than speed of sound without breaking the sound barrier?

The sound barrier is a function of airspeed and air density. If you have a strong enough tailwind, your ground speed would be above what most lay people would consider the speed of sound without breaking the actual sound barrier.

Aircraft (or any object moving through the air alone) are governed by airspeed. Ground speed is only relevant when traveling on the ground or transitioning to that state (approach to landing).


Circa 1942 Republic of Ecuador - Can someone identify the aircraft in the background?

Looks like a Fairchild PT-19...
https://en.wikipedia.org/wiki/Fairchild_PT-19


Why would a C150's tachometer fluctuate?

It has a little internal generator that creates a voltage to drive the needle.  The generator, and a gearbox that runs the hour meter, is spun by a flex shaft from the engine.  You can have problems stemming from the flexshaft binding and winding up/releasing, but there is probably an electrical issue with the internal generator or the circuit that drives the pointer.  A mechanic might swap out the flex shaft and see if it still does it, and if yes, swap out the tach.  Or vise versa (If I had an other tach handy, I'd disconnect the flexshaft at the tach and work it out from under the panel and connect it to my spare tach and try it out).

In any case, if it's a Cessna 150, and the tach's hour meter shows the airplane's original hours, no doubt it's 43 or more years old and is toast.


What were the J47's turbine blades made of?

It's very likely the J47 turbine blades used wrought iron, with alloying elements of aluminium and titanium. The General Electric J47 turbojet is a very very old design - it first flew in May 1948, only 11 years after Frank Whittle's first prototype gas turbine ran. It was the first axial-flow turbojet approved for commercial use in the United States, and was used in many types of aircraft. More than 30,000 were manufactured before production ceased in 1956.

This 1970 report gives a good summary of the materials used in early gas turbine engines.

It states that early turbine blade materials were either iron, nickel, or cobalt based alloy, both cast and forged. (i.e., there we're a mixture of materials, but the largest percentage of any one material was either one of those three).

Nickel based alloys are the ones that are mentioned the most. They are predominantly used today, and there are quite a lot of them (see table 5 in the 1970 report). But, the J47 is so old, it most probably only used an iron based alloy. This comprehensive report covering material development says, in the section on turbine blades:

  ....steadily increasing operating-temperature requirements for the aircraft engines resulted in development of wrought alloys with increasing levels of aluminum plus titanium. [But] component forgeability problems led to this direction of development not going beyond a certain extent. The composition of the wrought alloys became restricted by the hot workability requirements. This situation led to the development of cast nickel-base alloys.

So, Ni alloys were not used in very early engines. From above then, it is very likely the J47 used a wrought iron alloy, mixed with aluminium and titanium. This is also supported by Fig 1 from the Rolls Royce document mentioned below (the PDF download is free), which shows only wrought alloys used from 1940 to 1955:

A similar figure, from the TBC report mentioned below, shows Ni based "superalloys" have been used since at least the mid 60's (which is a decade after the J47 production ended!).

While the main constituent of the material hasn't changed since then what has changed is the method of manufacture, from wrought and forged with no crystal or grain orientation, to cast with crystals orientated along the axis of the blade (i.e. hub to tip, called uniaxial), to blades with single crystals. Also, air cooling now exits, with internal passages, and holes on the blade to provide a thin film of cooling air over its surface. The blades also have a thermal barrier coating, that is a ceramic material which basically insulates them from the hot gasses. Originally TBCs were used to gain extra life compared to the life required in the design specifications (i.e. the TBC wasn't necessary to met the base life requirement, but helped give more life). Now days the gases are so hot in some engines, the TBC is necessary just to meet the design specification minimum life. In this case, the TBC is known as prime reliant. See this article for detailed discussion of TBCs.

This article gives a very good summary of the development of turbine blade cooling technologies by Rolls Royce.


Is it possible for a plane to use cameras and screens instead of a clear windshield?

It's entirely possible to do this now, it's simply not a good idea. The drawbacks to safety outweigh the benefits of doing so. If you have no cockpit windows an electrical or systems failure would leave pilots totally blind, without any references whatsoever. The "mark I eyeball" works in a wide variety of conditions and does not require electrical power of any kind. Plus, there's usually 4 of them in the cockpit, and chances are at least one of them will work.


What is the reason aircraft are as long as they are wide?

By curious coincidence it is simply what the optimal aspect ratio for speeds around 250–280 knots indicated results in. Aircraft designed for different cruise speeds have different ratios.

The wing span is governed by desired cruise speed. There are two main forms of drag—induced and parasite. Induced drag decreases with wing span and with speed, while parasite drag increases with them. So at lower speed, you need long wings to keep the induced drag at bay, while parasite drag is low simply because of the low speed. And at higher speed, you need shorter wings to avoid too much parasite drag.

Jet aircraft are most efficient at transsonic speeds (Mach number 0.75–0.85) and altitudes around 10-12 km (33,000–40,000 ft) and it so happens that the wing span and cabin length to contain corresponding payload are similar. Turboprop aircraft are most efficient at somewhat lower speeds and altitudes and consequently their wings are a bit longer. And yet slower piston-powered aircraft have even longer wings relatively to fuselage.

(update, as suggested in comments): The extremes are on one side gliders that achieve low drag by having very long slender wings and flying slow and on the other side supersonic aircraft that have short wings with long chord to keep the frontal cross-section low, the very extreme being the very fastest aircraft like X-15 or SR-71.


Where can I find standard aviation abbreviations for the "unit of measure"?

This is defined in ICAO Annex 5 - Units of Measurement to be Used in Air and Ground Operations


Did the Soviet Union build any commercial jetliners?

Of course. Probably more than any other single country except the US.

Tupolev Tu-104, one of the first jetliners. For a short time, when the Comet was grounded, it was the only jet airliner flying in the world.

Tu-124, its development, the world's first jetliner with turbofan engines.

Tu-134, further development; claimed to be the world's most produced twin jet of this class (80-pax).

Tu-154, a trijet, USSR's most popular airliner. (Similar to B727 or Trident).

Tu-204 was developed in the 1980s and is essentially 'Soviet', but never saw service in the USSR.

Tu-144, of course. Although it first flew a few months before Concorde, it had extremely limited commercial (or better say, 'civil') service.

Ilyushin Il-62, a long-range jet, a relatively rare example of a quad-jet with all engines on the back (similar to Vickers VC10).

Il-86, USSR's first commercial widebody, and its later development Il-96.

Yakovlev Yak-40, a small (30-40 pax) regional trijet, the world's first in its class.

Yak-42, the first Soviet jet with high-bypass turbofan; a trijet smaller than Tu-154.

All these jets (except Tu-144 and 204) were in wide use in the USSR, and most were exported at least to the Eastern Bloc countries and beyond. Of them, only Il-96 and Yak-42 remain in limited commercial use, although more are operated by air forces and government bodies.


What would happen if a pilot tried to land with a tailwind?

Your landing rollout will be longer, your groundspeed will be faster and you will stress the brakes more than a landing with less tailwind.  The same can be said for choosing calm winds over a headwind.

The jet I flew and many others have a limitation for maximum tailwind of 10 kts and it isn't unheard of to request an opposite direction landing (e.g. with a tailwind) if the tailwind is acceptable, the runway is long, and there is no conflicting traffic when it is convenient for the operation.

If you were forced to make a landing with a tailwind exceeding your limitations then the situation is probably an emergency and you'll want a longer than normal runway.  There is an increased threat of a brake fire, but in an emergency ARFF will be following you down the runway and they'll take care of it.  The tailwind landing only really becomes a problem if the runway isn't long enough (overrun) or if the tailwind is so strong that the maximum wheel speed is exceeded (loss of directional control or worse).


What is this object on the tail of an F-16?

Source: primeportal.net; cropped

That's the cooling-air outlet that is aft of the cooling inlet. In between is a power amplifier for the radar-warning system.

  Source: amazon.co.uk (one of the product images); cropped

  118: Cooling-air ram air intake
  124: Radar-warning system power amplifier

Related: What is the device at the tail of the F-16 Block 60?


What are those thin magenta lines on the Sectional / Terminal Area Chart near Death Valley?

Those lines denote areas of the MOA which have altitude exclusions different from what is listed on the chart's MOA table. In this case:

  MOA Excludes Airspace 3000' AGL & Below

Notice the same style magenta lines are drawn in circles around airports in the MOA which also have the same style remark excluding a specific portion of the airspace.


How did night fighter aircraft manage to shoot down their foes in World War II?

The night fighting in WWII was mainly between the RAF and Luftwaffe, with the Luftwaffe fielding most of the night fighters due to necessity (the others too had some fine night fighters, though none had their need as much as the Germans).
The first stage in (trying to) shoot down enemy aircraft is to find them. This was mainly done by the ground based radars. The second one is fixing them- this is where the aircraft based radars came into being.
Initially, the fixing of aircraft location was done using ground based search lights, which were sometimes controlled by radar after which the fighters attacked the illuminated target- but this was of little use as was the aircraft based searchlights. It was only in the middle of the war did the development of night fighters gained pace.

A Messerschmidt  Bf 110 G-4 night fighter with FuG 202/220 Lichtenstein radar; By Max Smith - Own workMoved from en:Image:ME-110G-2_at_RAF_Hendon.jpg, Public Domain, Link
The night fighters were usually twin engined aircraft fitted with radars, though there some single engined ones too. The fighters were still vectored into the bomber locations using the ground radar controller. An RAF report on PoW interrogation notes:

...The crews fly by D.R., and the loose formation is simultaneously tracked on a map at Gruppe headquarters. If, in the light of the movements of the bomber force a change of course is necessary, a new bearing will be given to all aircraft simultaneously through the Gruppe commentary.
All crews are given strict orders to navigate by D.R., and to
accept the Gruppe orders if these differ from their own calculations ...

Once the fighters were near the bomber stream (as the RAF usually bombed in strength to overwhelm the defences), they were given a new bearing to intercept the bombers.

... the string of night fighters should be brought up to the bomber stream on a parallel or nearly parallel track. At the correct moment, and in accordance with D.R. tracking at headquarters, the night fighters will be given a new bearing which turns the whole line on to the bomber stream in a broadside.

The enemy aircraft (bombers) were identified by their silhouette (against moon or the burning cities below) or by their exhaust flames.

Recognition of the target aircraft is usually by the silhouette in light conditions or moonlight, and by the four exhaust flames in darkness.

The actual firing of the guns depended on the pilot and different ones opted for different methods- some simply did as in dogfights during day- get into the rear and shoot up, though the rear gunners made this difficult. Others moved towards the aircraft from the sides and a little low, after which they pulled up near the aircraft and aimed for the wing fuel tanks.

The range at which the night fighter opens fire with its forward
armament is determined by the pilot himself; whilst some will close in
as near as 50/60 metres, the more cautious will open up at a range of
200/250 metres. P/W considered, however, that the normal range might be
taken as l00/150 metres.

One of the effective methods used by Germans was the upward firing cannon called the Schräge Musik, which was quite effective with its 20 and 30 mm cannon.

By Source, Fair use, Link
Basically, the pilots flew under the bomber and fired the Schräge Musik. This was quite effective as the bomber crews had little warning of the threat below and the bullets usually tore through the fuel tanks near wing roots.

[These P/W] ... they stated that once this armament (Schräge
Musik) could be brought to bear it was extremely effective; one officer had claimed a kill with two rounds from the 20 mm. cannon.

The night attacks were quite short affairs as it was quite difficult to keep the bomber in crosshairs for any amount of time (and there were enemy night fighters to contend with). Shooting down enemy aircraft took more luck than skill in WWII. According to this site, each enemy aircraft shot down required more than 10,000 rounds fired (the values are more or less equal for both sides), with night attacks probably requiring more ammunition. Also, this infographic has some good details on this subject.


Is it plausible to forget the cockpit unlocking code?

The code would also be shared among the purser and/ or the other flight attendants, so the answer is no. I believe however that they tend to keep the same code for a few days within the same crew to make remembering it easier.


According to the discussion here it seems a "cruise captain" is the captain who flies only during the cruise stage of flight. You can find a job listing for a "cruise captain" here but it does not elaborate much on the duties. To act as the pilot in command (at least by FAA regs) they would have to be current, and type certified in the aircraft in question. It seems the term is more a turn of phrase and the regulations are not any different for a cruise captain. On very long haul flights that may require 3 full crews, there will be a crew in the middle section of the flight that never sees takeoff or landing from the cockpit.

The report you have linked in the comments defines cruise captain in the foot note on page 3.

  Cruise Captain in this report refers to a pilot certificated as cruise
  captain by the Malaysian Aviation Authority, and is qualified by the
  company to act as PIC during cruise only and who was engaged in the
  operation of the aircraft.

It sounds like "Cruise Captain" in this case is a Malaysian Aviation Authority term (although it may apply elsewhere as well). I am looking for the actual regulation that defines it but have not yet come across them.


Airbus A320 automatic speed mode protection in SRS vertical mode

High speed protection is still available (in normal law) in SRS (check FCOM DSC 27 20-10-20).

What you will not have is the reversion mode of the autothrust to Speed. You will get the protection  (THS freeze, spiral stability to 0deg, max 40 deg bank, nose up order) but thrust will remain in THR CLB.

I suspect the reasoning was that SRS mode implies you are pretty low on altitude, and you do not desire an automatic (and uncommanded) reduction of thrust on, say, a windshear.

Of course, in this particular case the high speed prot will activate at VMO/MMO so if you manage to get that fast while still in SRS you have bigger problems than the thrust

For your second question: mode reversion to Speed will occur at VMAX (which is lower of VMO, VLE or VFE), but for SRS there is no flap overspeed protection so only VMO will trigger it


What has been the maximum number of failed landing attempts for any commercial flight yet?

As far as I know, nobody actually maintains a register of go around. A go around is not a failure, nor a fault.

However each missed approach reduces the fuel quantity which may become insufficient. The crew will not continue to try to land at the same airport if the likelihood of better conditions at the alternate airport are high.


The FAA provides an online reporting tool here I would say it falls under "aviation concern". In your description if you include tail number and time they should be able to figure out who was flying (or in the cockpit if its a 2 man situation). You can also contact your local FSDO and report the tail number and time of incident. Aircraft owners/renters (the people the tail number will trace back to) will more than likely know who was flying a given tail number at a certain time so as long as you know when it happened you should be ok its not necessarily on you to know who was flying but the tail number and incident time is key.


What happens to US military demo teams following unexpected pilot turnover?

I can't answer for the Blue Angels or the Thunderbirds, but I can for the UK equivalent, the Red Arrows.

The Red Arrows have no spare pilots (or 'B team'). The nine pilots on the team fly every display in their 3 year tour. The explanation is that a spare pilot would not fly frequently enough to be current and safe. They do however have the capability to do an 8-plane display (rather than the usual 9) which they can use if a pilot is temporarily incapacitated. They also have a spare plane, something I know also applies to the Thunderbirds.

In the event of any kind of serious accident, it is likely that displays would be suspended for at least a while, in order to investigate and also out of respect. If all pilots are available when displays resume everything would be normal, using the spare plane if required. If a pilot was out for a short time they might fly the 8-plane display. The Arrows fly standard planes with minimal modifications, so presumably a new one could be readied fairly quickly.

In 2010 when Flt Lt. Ling was injured too badly to continue with display flying he was replaced by a pilot who had already flown with the team in a previous season.


What does the ASDE-X ground radar unit look like?

This page claims to show the Raetheon ASDE antenna at Boston Logan. However, Saab Sensis appears to be the prime contractor for the ASDE-X system. Boston does have an ASDE-X system, according to the FAA.

According to the above link, Saab provides the "Multi-Sensor Data Processor" that "fuses the surface movement radar, multilateration, ADS-B and terminal radar data into a single track that is correlated with flight plan information." So my guess is that Raetheon provides the radar antenna and Saab does the software integration, alerting, fusing, etc. Since the contract is in the US there may have been a requirement to use a US radar supplier.

As an interesting aside, Saab recently announced a third generation Surface Movement Detection antenna, the SR-3:


For an electric airplane are propellers the only option for propulsion?

Propellers in some form are really the only option. It is currently the only efficient way to generate thrust with air as a medium. Even jet engines are in some sense just a very elaborate system of propellers.
The reason for the turbine is to create an environment to efficiently burn fuel (suck, squeeze, bang, blow) to generate as much thrust as possible. Hence, in an electric aircraft this is irrelevant. You might be interested in the Airbus E-Fan, which uses ducted propellers increase efficiency. However, it is still 'just' a propeller with an electric motor in the middle.


Statistics - Does the majority of new pilot training occur at controlled or uncontrolled airports?

No one really tracks these stats and they would be tough to track on any note. The latter half of my training was out of an uncontrolled field but lots of touch and gos occurred at controlled fields so I had lots of experience talking to the tower even though I was not flying out of a towered field.

  I'm interested in this because it would likely give an indication of
  the relative level of comfort of new pilots operating in both
  controlled and uncontrolled airport environments.

As a pilot you are responsible (as per the ACS) for understanding the regulations and procedures for both situations and in todays day and age it would be foolish for an instructor to not at least present both situations in your training. That being said, you can technically get your PPL in an airplane that does not even have a radio but you are still responsible for understanding the regulations and may be asked to explain them on your check ride.

  I assume that it's likely that a Designated Pilot Examiner would be
  more likely to operate out of a controlled field just due to traffic

The DPE that I went to was at an uncontrolled field (as are the other 2 in my area). Im not sure this is an accurate generalization.

Keep in mind the DPE will go over your logbook and may look at the airports you landed at. If you dont have sufficient towered experience they may ask extra questions about that but you may not be required to demonstrate it on your check ride.


What is the data size of Hilton Software's WingX Pro 7 app and all of its databases?

The app itself only takes up about 15-20MB, according to the Google Play or iTunes app store, where as ForeFlight takes up 226MB (almost a quarter of a gigabyte) and Avare is less than 2MB and free. After downloading a good handful of charts, Avare is about 250MB. If you are very tight on space and running Android, you could try Avare. Otherwise if you need WingX Pro 7 or are on Apple, 5-6GB is what you should have free if you plan to use all the charts. If you're buying a new tablet, try to go for a 32GB model to be safe and have plenty of room for other apps additionally, otherwise 16GB should also work.


Calculate parasite drag coefficient from drag polar

Well, $C_D = C_{D,0} + k_1 C_L^2 + k_2 C_L$ according to Brandt et al's "Introduction to Aeronautics: A Design Perspective," so the parasite drag coefficient is $C_{D,0}$ or 0.038.

(Also, $k_1 = 0.0458$ and $k_2 = 0$.)


What exactly do "attempt" and "cycle" mean in these starter duty limitations?

Three start attempts are considered one "CYCLE" (we talk this in terms of starting the engine, that engine will get started in atleast these attempts).
A gap of 20sec or 35 sec after each attempt (failed /successful) is required.
And the cooling period of 15 min after 1 COMPLETE CYCLE (or 4 failed attempts) is required.
hope this helps.


Does the Lilium VTOL wings produces lift during takeoff?

The take off is aided purely from the mini fans which is pointed vertically at the aft of the wing to generate pure vertical thrust. The wings will generate only drag and zero lift because the airflow(aerodynamic force) is attacking perpendicular to the chord line. Hence the wings are used only to aid the flight in cruise.


What is the format of the airport codes used in an ACARS OOOI message?

ACARS messages, unsurprisingly, use IATA airport codes.

See ARINC 618, 619, 620 etc.

- ACARS, Dr. Maarten Uijt de Haag, Ohio University


Why don't airplane piston engines have mufflers?

Today, most GA aircraft in Europe do have mufflers so they can pass the ever more stringent noise requirements. Here is one mounted to a Cessna 172 (picture source):

Historically, mufflers were considered as a disadvantage because they reduce engine performance by increasing back pressure. By partially blocking the exhaust flow, the muffler increases cylinder pressure on the last upstroke of the cycle (the exhaust stroke) so it faces more resistance against moving up. Also, more of the burnt gasses remain in the cylinder so less fresh fuel-air mixture can be ingested in the next cycle. At most, in aircraft with an open cockpit a tube was installed to duct the exhaust gasses away from the pilot. Below is a picture of a Mercedes D.IIIa in a Fokker D VII (source):

However, night flying would make aircraft easily detectable by their exhaust flames, so in WW II tubes were added to the exhaust stack in order to avoid optical detection. Below is a picture of an Avro Lancaster with Bristol Hercules engines (source):

Our much better understanding of piston engines now allows to design mufflers which do not cause much power loss and in case of a tuned resonance muffler you even get more power at the design speed because a reflected pressure wave will arrive from the muffler at the exhaust port just when the valves close and will increase cylinder pressure. However, given the low RPM speeds of our old-fashioned aviation piston engines, those mufflers need to be large and the equally old airframe designs have no space for them. So in aviation the mufflers are still causing a power loss.


How do electric carbon monoxide detectors work?

There are three major types of carbon monoxide senors.

Biomimetic: A gel changes color when it absorbs carbon
monoxide.
Metal oxide semiconductor: When the chip's circuit detects
carbon monoxide, electrical resistance decreases, and this
triggers an alarm.
Electrochemical: Electrodes immersed in a chemical solution
sense changes in current when they come into contact with carbon
monoxide, and this change triggers the alarm.


What is the time information on the G1000 MFD map during a hold?

It's most likely an Expect Further Clearance (EFC) timer. You didn't mention the aircraft type but there are several references to it online: Garmin service advisory; Seneca V impressions; Archer manual quoted in a forum. My G1000 experience is in a C172 and I've never seen it there (I can't find it in the manual either) but the features are different depending on the aircraft, so it's possible that EFC timing just isn't in the C172 version.


What are the certification requirements for software used at airports?

The short answer is yes, With larger airlines, they may own and manage their IT infrastructure at central hubs, so the airline will need to ensure their software works with their chosen peripherals. At smaller airports where this is not possible, many airports use a common use computer platform, managed by both the airport authority and commercial IT vendors. Ultra is one such example. Airline DCS software would need to undergo validation to ensure it will correctly interface with the various devices at the airport: bag tag, boarding pass, document printers, self-check-in kiosks, and gate scanners.

The Passenger and Airport Data Interchange Standards (PADIS) Board as well as the
Common Use Working Group (CUWG) provide direction to IATA for creating technical standards. CUPPS (Common Use Passenger Processing Systems), is the IATA standard recommended practice for such common use computer systems.

DCS systems also must be able to transmit advance passenger information to government agencies, for example TSA to verify the passenger is not on a terrorist watch lists. Requirements for transmitting such information is set by the UN EDIFACT PAXLST specification, but not all passenger information transmissions will be sent from a DCS system.

EASA and FAA are more focused on flight data (flight plans, ATC, and weather) and have specifications for receipt and transmission of that information, but the transmission is usually done by separate software.


Are directional instruments like an HSI or AHRS immune to magnetic compass error?

The short answer is yes, but for different reasons.

The analog HSI in most aircraft that have them either has an internal directional gyroscope, or it is slaved to the directional gyro (more often the former than the latter as the HSI often replaces the DG). An analog DG/HSI must still be periodically corrected for precession error by levelling off, letting both instruments stabilize and then adjusting the HSI's card to the magnetic compass.

AHRS systems that power glass cockpits use a solid-state directional gyro that is corrected by a magnetometer (an antenna device that directly senses the relative direction of the magnetic field) rather than a floating magnet. This makes them impervious to the types of error commonly seen in floating compasses such as acceleration bias (which causes all the behaviors you mentioned). They can still be sensitive to nearby ferrous metal structural members and to electrical currents, requiring a digital version of "spinning the compass" with corrections input into the software that uses the magnetometer readings, and magnetic declination must also be accounted for (either mentally by the pilot, manually based on declination charts or in more sophisticated systems by directly incorporating position data from the GPS).


Question about congestion of the 1090MHz frequency

Additionally, there will be more aircraft interrogating (on 1030MHz) and responding to interrogations on 1090MHz for transponder based systems (TCAS, SSR).

Actually, no. More Mode S (vs Mode A/C) aircraft means TCAS can use Selective interrogation instead of All-Call interrogation, which will reduce congestion from unnecessary replies.
Also, newer TCAS systems are ADSB-aware and will reduce (not stop, for safety reasons) even their selective interrogation rate for ADSB targets, further reducing congestion.
Also also, part of the goal of ADSB is to reduce the need for SSR overlap, which will greatly reduce congestion as well.

... bandwidth limitations of 1 megabit/second. What does this mean?

Remember that this is a spatially distributed system, so congestion observed varies for each receiver based on which subset of transmitters they can hear. How far you can hear depends mostly on how high your antenna is.
The bandwidth number is a theoretical maximum data rate based on the bits per message and number of messages per second, assuming no overlap and no gaps. It will never happen in practice; it’s only useful as a yardstick for the current data rate.

What is physically limiting bandwidth? Will there eventually just be too much interference between signals whilst using this frequency,

Yes, see above.

Are the solutions to increasing capacity about being more clever with how the packets are sent (more efficient packet sizes, fewer packets, better/cleaner transmission),

The protocol is already as clean and efficient as it can be while remaining compatible with older Mode S equipment.
Most of the congestion comes from frequently sending redundant data as a crude form of FEC. Turn that off and congestion would go away, but so would the ability to gracefully degrade.

improving ground or air hardware,

One vendor (Airspy) claims to be able to decode overlapping messages, which if true would drastically reduce data loss and raise the practical bandwidth above the theoretical maximum. But I don’t know how well it works in practice or whether anyone is pursuing this for certified hardware.

or is there a "add more lanes to the highway" solution? It seems 978MHz is equivalent to adding more lanes.

That is allegedly why the FAA pushed UAT978 for light GA aircraft in the US.

What is the consequence of congestion? Are packets corrupted as noise rises?

The only real problem is collisions, not noise. Unless you define unreadable-due-to-collision messages as noise, of course.
The consequence is simply that you miss any data whose message was unreadable. However, the protocol was specifically designed to be highly redundant to minimize the impact of low to moderate levels of loss. Exactly how much loss it can tolerate is not clear, but so far it doesn’t seem to be a problem in practice.


Why is the clearance delivery frequency included on an approach plate?

The FAA Aeronautical Chart User’s Guide: Terminal Procedure Publications in section “Bottom Briefing Strip (Communications Information),” page 15 in the revision effective 29 March 2018, explains:

The communications briefing strip contains communication information when available, in separate boxes, listed from left to right in the order that they would be used during arrival …

Clearance Delivery (CLNC DEL) frequencies; where a Control Tower does not exist or is part-time, a remoted CLNC DEL may be listed …

Relevant to the briefing strip in the question, this section adds

Note: Part-time operations will be annotated with a star. Check Chart Supplement for times of operation.

According to the Chart Supplement for McClellan-Palomar, the tower is indeed part time.

AIRPORT REMARKS: Attended 1500–0600Z‡ …
COMMUNICATIONS: …
    TOWER 118.6 (1500–0600Z‡)

Other use cases when having the clearance delivery on the approach plate is convenient are obtaining a new clearance during a brief stop and closing an IFR flight plan through clearance delivery, either local or remote, when the tower is closed.


Can astronavigation be used during flight?

You sure can! It's not really done all too much any more in the days of GPS but it was done quite a bit in the early days of aviation. Historically, this was done by the "flight navigator" a position that no longer really exists. Some aircraft even had mounted sextants.

(source)

Here is a video of it being done in practice (fanta optional)

This was even automated on the SR-71's Inertial Astro-Navigation system which used the stars to align itself.


Does installing a PTZ dome camera outside the aircraft violate any FAA rules?

Aircraft out there already use external cameras for use during taxiing/landing. Airbus uses a system called external and taxiing aid camera system (Etacs) in A380 and A350, which uses three cameras:

One camera in nosewheel well gives a view towards the aircraft’s nose gear.
A second camera mounted on the vertical tail gives a high overview of the aircraft from the tail.
Another camera is situated on the belly of the aircraft for giving views of runway below.

Note that both of these are FAA certified and under operation.

Whether or the camera affects the aircraft performance depends on the aircraft and the camera used (and installation location), though in most cases it shouldn't. In that case, you may have to get a supplementary type certificate


Does the payload of an ICBM or regular airplane bomber explode if the ICBM or bomber is shot down?

Usually it won't set off the payload.

The payload is designed in a way to prevent it from going off prematurely - say it needs to be armed before it can go boom. Usually you would only arm the trigger mechanism in the end phase - directly before payload delivery since you want to hit your target and not your own installations.

Modern explosives are remarkably unwilling to go off without the correct primer. Some of them will not explode even when set on fire (and just burn in that case). However some others might go off if they just get heated enough.

For nuclear weapons, it's even more difficult to determine. If the conventional explosives go off in an unpredicted pattern, you might have a conventional explosion but not a nuclear. If these explosives do not go off in the right pattern, the bomb might never reach criticality and fission (and possibly fusion) stage of the weapon will never trigger. In any case, wherever it went of, the bomb might scatter plutonium, uranium and other radioactive material where it was shot down.

That said, an aircraft or missile crashing can cause ordnance to arm and there was at least one case where a US bomber with live nukes crashed, the bombs partially got armed on crash but didn't trigger in the end. https://en.wikipedia.org/wiki/1961_Goldsboro_B-52_crash


At a controlled airport, the tower will route you or other aircraft as needed for seperation. If IFR, you will have a clearance to follow if you have to go around, either from ATC for that area, or as published, and once following the clearance you will go back to ATC for further information.  At a non-controlled airport and IFR, the same will apply. If you land, you call and cancel the clearance, if airborne and you are talking to ATC and have visual to land, you may be able to cancel while airborne.

VFR is similar - either tower will direct you as needed, or you see and avoid when non-towered.   If you use flight following, you will be talking to ATC until you get near the airport, they will often advise you of any nearby traffic before cutting you loose for your own approach and landing, with their last direction being something like "Nxxxx, airport is at your 12:00 and 8 mile, you have traffic at 1:00 and 5 miles, squawk 1200, frequency change approved."


The regulations regarding the logging of time are specified in FAR Part 61.51 (Pilot Logbooks):

(a) Training time and aeronautical experience. Each person must document and record the following time in a manner acceptable to the Administrator:
(1) Training and aeronautical experience used to meet the requirements for a certificate, rating, or flight review of this part.
(2) The aeronautical experience required for meeting the recent flight experience requirements of this part.

Time other than (1) and (2) above does not need to be logged as it can't be used other than as specified in (1) and (2) above.
That being said, you can put/log what ever you want in your logbook in order to record the flight for historical purposes.  But as for "Total Time" to satisfy the requirements for a certificate, rating, or flight review OR the aeronautical experience required for meeting the recent flight experience requirements of Part 61, the time you are with your friend (as a tag along, and not giving instruction) cannot be used for any purpose specified under 61.51.
Further, since you are not performing the duties of a safety pilot, a required crew member or in any required capacity as a pilot, you can't, for the purposes of meeting any requirements/conditions specified under FAR 61.51, log and receive benefit of the time as "Actual Instrument" time.


Are paper charts required for flights outside the USA?

With virtually every major US air carrier today using EFB's, the use of paper charts in the flight deck has largely fallen to the wayside. Flight crews are still being provided with the exact same information, only now it is in digital form. Most, if not all US air carriers use navigational charts and plates published by Jeppesen. Unlike FAA NACO charts and plates, Jeppesen publishes charts for airports all across the world in a greatly standardized form. This allows information to generally remain similar across countries and helps to reduce some of the differences pilots operating international flights would otherwise face. Whether paper or digital, US based flight crews would likely receive charts from Jeppesen.

All of the EFB apps in use by airlines are designed to automatically provide pilots with current charts and plates needed for any given flight in the carrier's network, provided the area is covered in the chart subscription. Prior to operating an international flight, an airline (likely their dispatch department) will review their chart subscription package to ensure charts/plates are included to cover the routing, destination, and alternate(s) of any international flight. Any areas needed that are not currently included in their subscription would be added. Once added to the airline's subscription, the charts would then automatically populate to the EFBs issued to pilots. Pilots would then just need to make sure the new charts were downloaded and they would be good to go. Pilots would then be receiving the exact same information digitally that they would if they had been provided paper charts.

From a regulatory perspective, the FAA, EASA, and ICAO have all developed standards for EFBs and as a result pretty much all developed countries allow their use. As long as an airline has received the appropriate approvals and meets standards, the use of EFBs should be a non-issue. In the US, FAA EFB standards meet or exceed ICAO standards, and ICAO standards would likely be the minimum requirement while operating internationally. I am not currently aware of any country that disallows the use of EFBs for charts, but should such a scenario arise, then an airline could potentially be forced to use paper charts. However, the odds of that happening are slim to none.


Has a flight data recorder or cockpit voice recorder ever failed in an accident?

As mentioned in the comment above, there is lot of aviation accidents with unrecovered flight recorders. List from wikipedia:
https://en.wikipedia.org/wiki/List_of_unrecovered_flight_recorders


Does operation under ETOPS rules require additional procedures in flight during the ETOPS segment?

Most of the action for ETOPS flights takes place during planning and dispatch stages- the planning for alternate airports, gathering of weather reports for diversion cases etc. Before ETOPS entry point, the weather reports are updated and checks are made; after that there are no 'special' procedures to be followed during a (normal ETOPS) flight.

From Airbus ETOPS Guide:

  3- IN-FLIGHT ETOPS PROCEDURES

  b) Weather update

  − after ETOPS Entry Point:

  The crew should continue to update the weather forecasts and reports
  for en-route alternates.

  As for a normal flight, the crew must make every effort to keep
  themselves informed on the weather at the destination and the
  destination alternate.

  c) Fuel monitoring

  The procedures normally used as per airline policy is also applicable for
  ETOPS.

  This is true even for flights where ETOPS fuel planning is the limiting factor.

In case of diversion (say due to an engine failure), the PIC will take a decision like any other flight, though he/she cannot fly beyond the nearest suitable airport.

One way of looking at this is that the main purpose of ETOPS certification is to improve the robustness and reliability of the design and operator to a level that the ETOPS flight could be conducted like any other normal flight in the ETOPS segment.


When does the airline check if an airplane can reach its destination?

The spec-sheet range is not a fixed value—

The range of the RJ85 (BAe 146-200) is 1,570 NM with standard fuel capacity.
Range values are only valid for certain (marketable) payload/fuel levels.
If you have less payload and/or more fuel, you increase the range. Example here.
If there is tailwind, the [air] distance to destination is reduced (apparent range is increased). That's why marketed range circles are not circles, as shown below. Example here.

  The wind may provide a head- or tailwind component, which in turn will increase or decrease the fuel consumption by increasing or decreasing the air distance to be flown.— Wikipedia

Corrected distance (after the average-wind is taken into consideration) is checked in the flight planning phase, and the plane is loaded accordingly (fuel and payload). If the aircraft can't reduce the payload to reach its destination, then a technical stop to refuel is planned.

Google Flights shows all the airlines stopping at least once on the way.

(Source) Range circles take into account the trade winds.


First actual flight lesson, what to keep in mind?

Bring a camera. That's about it.
Unless you're training part 142 (you probably aren't) and were given homework (you probably weren't) your first flight is where you get to see what it's like to be in a small airplane, feel the controls, and get a sense of practices and procedures.
Nobody expects you to be good at anything at this point.

Instructor responsibilities during the first lesson:

Ensure the safety of the flight
Introduce you to the airplane and to basic flight operations, including straight and level, basic turns, climbs, and descents.
Answer your questions
Get your contact information and learn when and how you would like to be contacted.

Student responsibilities during the first lesson:

Be a sponge: look, listen, absorb.  You're not going to understand everything the first time, but start getting the general feel.
Ask good questions. Your instructor will be able to answer them, or if they're not relevant, she'll defer them to a later time when you have more foundational knowledge to build an answer on.
Ask stupid questions.  You're on day one.  How are you supposed to know a good question from a stupid question? If you're afraid to ask the stupid ones you'll miss out on asking the good ones.  Your instructor doesn't care about stupid questions. She'll either defer them or respectfully let you know that they're not relevant. If she's an excellent instructor she'll also file away the fact that you asked as a point of possible misunderstanding to touch on later when you have a better base of knowledge.
Get your instructor's contact information and learn when and how she would like you to contact her.
Take a bunch of pictures. It's your first flight lesson!

Only one of these requires advance preparation. Got a camera? Good. Go have fun.


Is there a fixed-wing aircraft that uses a scissor propeller configuration?

The tandem-engine Rumpler-Loutzkoy-Taube airplane.

Above is the closest thing to a scissor propeller I could find. As @PeterKämpf notes, unlike a tail-rotor, a tractor propeller is not in a rotor's downwash and its axis of rotation is aligned with the free stream.

The photo shows the world's first co-axial propeller. And it was non-contra-rotating, that is, both propellers rotated in the same direction, like the Apache's.

That, and not being co-planar, are the matching features. Each propeller was powered by a different engine, and they could run at different speeds. Long before variable pitch propellers, it was envisioned (and patented) that the second propeller could have a gearbox to reverse its direction for braking (aircraft at the time didn't have brakes).

Source: oldmachinepress.com


Limits on piston-engine power for a given airframe?

It really depends on how long you want to fly for. Big engines generally require a lot of fuel so dropping a huge power plant on a small airframe may burn through all the fuel you can practically carry fairly fast. But if we assume that you don't want to fly all that long then we run up against the next issue.

You can always try to bolt a merlin engine to a C-150 airframe if you are willing to get creative with your bracket fabrication and perhaps beef up the nose wheel. The issue you will run up against here is at least in part a CG issue. A 1600LB engine on the front of an 800 LB airframe is bound to get interesting. But lets say you move the wings around, and put some ballast in the aft areas to even it out a bit and get a workable CG. You now have nearly 1600 HP up front to have fun with. So what happens?

If you can get this beast to fly you will eventually hit aerodynamic issues depending on the airframe, like Mach Tuck and ultimately at some point you are just going to rip the airframe apart.

So you need to balance structural integrity, aerodynamic stability, CG, the ability to carry enough fuel to actually do something practical and the limits of actually building an aircraft mechanically. There are also practical limits on scaling piston engines in general.


Why hasn't the US military performed aftermarket modifications on certain aircraft?

I think the main reason is that many of these planes were produced before winglets were common
Look at a list of USAF planes and see what years each one were produced (I am not including every plane, but most of the common ones)

C-5: 1968–1973, 1985–1989
C-17: 1991-2015 (has winglets)
C-130: 1954-present
E-3: 1977-1992
KC-10: 1979–1987
KC-46A: 2013-present (does not appear to have winglets, even though recent)
KC-135: 1955–1965

But when you look at this story about winglets, there is the sentence

The first 747-400 was delivered to Northwest Airlines in 1989, the
first commercial aircraft with proper winglets.

So for the most part you are talking about adding winglets to an existing airframe, rather than aircraft with winglets as part of the design.  This increases the expense of adding winglets, which reduces their cost-effectiveness. Look at this article on modifiying the B-52 to use four modern engines and the problems with that (not all of these would apply to winglets).


For routes over oceans, are slide rafts fitted with first-aid items, food, water, radio, etc?

(Source) A Boeing 747 raft survival kit.

Typical content does include nonperishable food and bagged water—

Base kit:

  Survival Manual
  Flashlight, w/Lithium Batteries
  Knife Assy., Utility
  Signal Mirror Assy.
  Sea Dye Marker
  Raft Repair Kit
  Whistle Assy.
  Water Package Assy. (4.23 fl. oz. per pack)
  Bailing Bucket
  Sponge
  Lip Balm
  Adhesive Bandage, 1 in (16 per box)
  Bandage Compress, 2 in (4 per box)
  Bandage Compress, 4 in (1 per box)
  Triangle Bandage, 40 in
  Adhesive Tape (2 rolls per pack)

Renewal kit:

  Sea Sickness Pill Packs (12 tablets per pack)
  Day/Night Flare
  Water Purification Tablets (50 tablets per bottle)
  Antiseptic Swabs (10 swabs per box)
  Ammonia Inhalants (10 vials per box)
  Burn Compound (10 tubes per box)
  Eye Dressing Packet
  Candy (Sucrose) Rations (10 candies per pack)

It's the crew responsibility to gather the kits.

They're located near the exits either in closets, ceiling compartments, attendant seat stowage, or overhead bins. Exact location varies by plane and airline.

Axes, first aid kits, ropes, fire extinguishers, megaphones, etc., are also stored in the same locations mentioned above.


Can drone with two propellers above one another fly vertically upward without spinning?

Yes, because spinning in the opposite direction produces counterbalancing torque. Those rotor over rotor models adjust yaw by small variations in the speed of the rotors, so that one produces a bit more torque than another.

There are a number of large helicopters that use two main rotors to the same effect, such as the CH47 Chinook (front and rear) and the Kamov KA31 which uses the same rotor over rotor configuration as the model you picture.


Can a US pilot fly a foreign registered aircraft in the US?

Yes. 14 CFR 61.3(b) covers this (my emphasis):

  (b) Required pilot certificate for operating a foreign-registered
  aircraft within the United States. No person may serve as a required
  pilot flight crewmember of a civil aircraft of foreign registry within
  the United States, unless—

  (1) That person's pilot certificate or document issued under §61.29(e)
  is in that person's physical possession or readily accessible in the
  aircraft when exercising the privileges of that pilot certificate; and

  (2) Has been issued in accordance with this part, or has been issued
  or validated by the country in which the aircraft is registered.

So a US license (i.e. one issued under part 61) is allowed as an alternative to a foreign license for operating the foreign aircraft. The other country could have rules on this too, but I have no idea if they would be enforceable (obviously, one country's laws are usually not valid in another one).


Is it possible to control a drone with a link mediated by the cellular phone network?

Possible: yes

Probable: no

The simple fact is that the cell network is not advantageous for drone control at least not the kind that people prefer. The architecture of the network by nature allows the signal to drop out bandwidth from tower to tower is not guaranteed. This would allow a situation where a drone flying along would get handed off to a tower that has no available bandwidth and the control signal drops out. Dedicated satellite networks allow point to point communication as well as assured bandwidth when its needed.


Did the Wright brothers discover the three-axis control system for airplanes/gliders and the adverse yaw?

The patent lawyer is explaining things quite correctly and this applies to modern aircraft.  The rudder does in fact have nothing to do with steering the airplane.  Its job is to keep the tail lined up behind the nose (or to move the tail out of alignment with the nose if you wish) mainly overcoming adverse yaw caused by warping (or later, ailerons).

The bolded text in the paragraph you quoted describes the wing warping being for roll control, and the rudder for controlling for the adverse yaw that results from the wing warping (same as aileron displacement in modern aircraft), just like any modern aircraft.  He is describing how a modern airplane flies in other words, and this was a pretty radical idea at the time so it didn't make sense to a lot of people.

The Wrights discovered adverse yaw as they were developing their totally new wing warping system concept, as it was abundantly obvious from the way the nose would slew the opposite direction to the wing warp input and a rudder control was the obvious solution.  They didn't get it from anybody else because nobody else had thought of the concept of differential lift to control bank in order to turn.   Lillienthal, from whom the Wrights based a lot of their work in the beginning, used weight shift to control his gliders.

I recall from books I read on the Wrights years ago that they proceeded originally from from Otto Lillienthal's aerodynamic theories, and as they tested their glider machines, they started to discover that Otto had a lot of things wrong, prompting them to build their home made wind tunnel and start development from scratch.

So I would say for (1) yes, they invented the 3 axis control system, that is, all 3 being used together to make coordinated banked turns, because they developed and patented wing warping (ailerons coming later and leading to a long patent legal battle with Glenn Curtiss).  Up until then, and for some time after, developers were controlling turns by skidding using rudders (helped by dihedral effect to achieve banking in some cases) or by weight shift, or in Bleriot's case trying to achive roll control with differential elevator movement like an F-15 to get around the Wrights' wing warp patent (which they defended furiously, leading to the long patent battle with Curtiss, who ironically ended up taking them over in later years and becoming Curtiss-Wright, a running concern to this day).

The proof of this is obvious if you read of the various accounts describing the Flyer's demonstrations through the mid 00s.  The Flyer's contemporaries, such as they were, would slither about the sky, whereas the Flyer flew around making coordinated banked turns like a modern aircraft.  This astounded observers, especially the French when the Wrights demonstrated the Flyer in France.  The French reaction to the Flyer was really something else, one of awe, admiration, and a bit of jealousy, that those two American yahoos brought a flying machine that could literally fly circles around machines like 14-bis.

So for (2) I would say the answer is also yes because they invented differential lift for roll control in order to turn, which quickly indicated the need for a rudder to counteract adverse yaw and which followed on naturally.


Linking equivalent airspeed with waypoints, altitude, time and speed

No, it is not possible to derive EAS from the data provided.

  p=Actual density

  p(o) = standard Sea Level Density

  TAS = True Airspeed.

You can get to actual density from the pressure altitude and temperature (ISA+ or raw).  Without temperature, it is impossible to derive air density from pressure altitude; only estimates are possible.  For a more in depth derivation, this is a good source.


How does altitude affect the speed of sound?

I read once that Mach speed decreases as altitude increases.

The speed of sound is solely dependant on temperature.

$$
M = \sqrt{\gamma RT}
$$

where $\gamma$ is the ratio of specific heats, $R$ is the molar gas constant and $T$ is the temprature in Kelvin. For Earth's athmosphere at 15° Celsius,

$$
M=\sqrt{1.4\times 287\times 288.15}=340\,\text{m}/\text{s}
$$

Does temprature decrease with altitude? Well, not always as can be seen by the international standard atmosphere:

(source: cam.ac.uk)

  ....are the pressure waves made at high altitude lesser than the ones at
  low altitude because of the difference in air pressure?

There is no simple answer to this. Here's NASA's opinion:

  Altitude determines the distance shock waves travel before reaching
  the ground, and this has the most significant effect on intensity. As
  the shock cone gets wider, and it moves outward and downward, its
  strength is reduced. Generally, the higher the aircraft, the greater
  the distance the shock wave must travel, reducing the intensity of the
  sonic boom. Of all the factors influencing sonic booms, increasing
  altitude is the most effective method of reducing sonic boom
  intensity.


I have really intense ear pain during descent in commercial flights. Would it be better or worse if I was flying a small non-pressurized plane?

Commercial airliners are generally pressurized to a cabin altitude of around 8000 feet when at high altitudes. So it depends a bit on where you live. If you live near sea level, you're feeling around 8000 feet of pressure change. If you live somewhere higher like Denver, you're only feeling around 3000.

Small unpressurized planes, especially ultralights, will tend to fly at lower altitudes, usually within a few thousand feet from the ground. If you live at a lower elevation, this will be much less pressure change than in an airliner. If you live at a higher elevation, it would be more comparable.

That being said, it may only take a few hundred feet of elevation change for the pressure to noticeably change, and each person may react differently. If you're worried about making commitments to flight training before you know how you'll handle it, you can go on a discovery flight, even just in a small Cessna.


Does ICAO allow continued flight in RVSM airspace after a transponder failure?

Note: I assume bare ICAO requirements in this answer. Most states that have RVSM implementations, as well as operator approvals for RVSM, will have additional stricter rules that will change the answer for specific cases.

There are no requirements in the ICAO Annexes and SARPS that require and aircraft the leave the RVSM airspace if the transponder fails.

Note that RVSM airspace is not necessarily airspace where ATS Surveillance services are offered, so for ATC purposes, a functioning transponder is not strictly necessary in RVSM airspace.

The only other use of the transponder that could prevent flying in RVSM airspace (under bare ICAO regulations) is the Airborne Collision Avoidance System (ACAS/TCAS). There are no requirements to have a functioning ACAS/TCAS in ICAO RVSM requirements, so no transponder is needed in support of such requirement.

Even if a transponder would be necessary to enter RVSM airspace (which is the case in for example EASA regulations), a transponder failure while being in RVSM airspace does (under ICAO rules) does not necessarily mean that the flight has to leave that airspace ASAP.

The following is from ICAO Doc 4444 (PANS ATM).

  8.8.3.3    AIRCRAFT TRANSPONDER FAILURE IN AREAS WHERE THE CARRIAGE OF A FUNCTIONING TRANSPONDER IS MANDATORY

  8.8.3.3.1    When an aircraft experiencing transponder failure after departure is operating or expected to operate in an area where the
  carriage of a functioning transponder with specified capabilities is
  mandatory, the ATC units concerned should endeavour to provide for
  continuation of the flight to the aerodrome of first intended landing
  in accordance with the flight plan. However, in certain traffic
  situations, either in terminal areas or en-route, continuation of the
  flight may not be possible, particularly when failure is detected
  shortly after take-off. The aircraft may then be required to return to
  the departure aerodrome or to land at the nearest suitable aerodrome
  acceptable to the operator concerned and to ATC.

  ...

Flight in Class A airspace without transponder is possible under ICAO rules, as long as the airspace is not surveillance airspace. Procedural air traffic control does not require surveillance, and a transponder is therefor not required.


On SIGWX (significant weather) charts, what does **/** mean?

http://www.beyourowncaptain.com/downloads/files/Reading%20Prog%20Charts.pdf
http://aviationweather.gov/static/adds/docs/metars/wxSymbols_anno1.pdf

Asterisks are snow, dots are rain. The slash means a mixture of the two.

The dot with an R under it is a substitution for the the thunderstorm symbol.

What you're looking at isn't a real SIGWX chart, it's a testing figure.


How could I match the surrounding traffics displayed with their radio communication

Several approaches, currently impractical for GA:

Your radio receiver would need to be directional, to estimate the
sender's bearing and maybe distance, and from that derive the
sender's identity.
Voice broadcasts would need to be augmented with a digital squawk
indicating the sender's call sign, like some automated speech
broadcast weather reports do.
Onboard automatic speech
recognition
trained particularly for call signs could try to infer the sender's.

But we're a long way from duplicating how videoconfering software highlights whoever's speaking.


Was the unmanned flight and landing of the Buran spacecraft in 1988 exceptional?

Your question is very subjective, but I think there are two ways to look at it:

Building a working space plane is pretty exceptional.

or

There's really nothing it did that wasn't done by something else.

The NASA shuttle was flown in fully-automatic mode for launch, and most of reentry. It's also the vehicle which pioneered the thermal tiles, the reentry profile of a space plane, and the general concept of a shuttle. Buran could almost be thought of as an iteration on that design. The Soviets used some lessons learned and, in some respects, built a better shuttle. Does that in itself make the Buran exceptional? Probably not.

The only thing Buran really did that the NASA shuttle never did was fly unmanned, including an automatic landing. That seems to be at the heart of what you're asking, so I'll address that specifically.

Autoland had existed for decades before Buran, so it certainly wasn't the first airplane to land on autopilot. Although, it may have been the fastest autolanding to date, which could be an argument for exceptional.

I would note that even though there was only one orbital flight of Buran, there were atmospheric tests of prototype vehicles (some prototypes had jet engines), so there were opportunities to safely test the autopilot during the landing phase of flight prior to the orbital test. In fact, it would have been the only phase of the autopilot that saw real-world testing prior to launch. So once Buran got on approach, the fact that landed safely probably shouldn't be too much of a surprise.

Lastly, I've heard and read many times how amazing it is that Buran landed so close to centerline in such a dramatic crosswind (around 33 knots). I think that would indeed be pretty impressive... if it were true. However, I urge you to go look at video of Buran landing (example, mute recommended). Does that look like a 33 knot crosswind to any pilot? To me, it looks like about a 5-10 knot crosswind at most. You see the wings doing very little correcting, and the wheels touchdown at almost the same time, which is very much not indicative of a crosswind.

For comparison, take a look at STS-133 landing. Note the wing movement at 8:58 which is to correct for about a 12-knot crosswind gust, which looks about right to me. Notice how the upwind wheel hits the runway about a second before the downwind wheel hits - very indicative of a crosswind.

I have no idea where the crosswind number came from, but it was almost certainly exaggerated, either on accident (perhaps mistaking wind conditions on approach for surface wind), or intentionally exaggerated to show how great and superior Buran was. Either seems plausible to me.

I tend to be in the camp that says anything you build which successfully goes to space and comes back safely is pretty exceptional, but I wouldn't say Buran was a tremendous advancement over existing technology, and ultimately it's always going to be difficult to really assess a ship which only flew once.


How can the lift induced drag for a wing be calculated?

Induced drag is the portion of the lift force that opposes motion.  Induced drag exists even when the drag coefficient CD in your equation is zero.

Lift is perpendicular to the air flow relative to the wing.  Imagine a wing moving right to left across your screen.  The air is moving left to right relative to the wing.  If there's no vertical induced airflow then the lift is vertical and there's no induced drag.  However, lift deflects the air down, so typically the air relative to this wing is not moving exactly left to right, but is tilted down slightly.  Hence, the lift, which is perpendicular to that airflow, is actually tilted back (right) slightly.  That means a (typically small) portion of the lift is "pushing this wing back," opposing its right-to-left motion.
If you know trigonometry, induced drag is lift times the sine of the inflow angle, $ L\sin \phi $.  The inflow angle is the angle of the airflow relative to the horizontal in this picture.
There's a picture of exactly this at the bottom of this page in the induced power section.  (Induced power is the power required to overcome induced drag.)


Short answer

Based on past observations and a study led by Patrick Minnis from NASA, contrails could result in increasing the temperature over the ground by 1°C every 30 years over the US.

From a study by German researchers Ulrike Burkhardt and Bernd Kärcher, the effect of contrails is comparable in other areas with a similar level of air traffic.

Because the air traffic is said to be about to increase very quickly, the effects of contrails on the temperature may increase too.

Contrails and natural cirrus: So similar that studies are difficult

Contrails are like cirrus, and actually some just become persistent cirrus. Sometime it's difficult to tell which one is a condensation trail, which one is a natural cloud. This makes more difficult the study of contrails effects, and introduces many uncertainties that need to be reduced:

(source)

The current studies take into account only the young contrail-cirrus, because they are still relatively easy to differentiate from natural cirrus, due to their linear shape. Most aged contrail-cirrus are not differentiable and are not counted as aircraft generated. This means the current results potentially under-estimate the effects of contrails.

Pertaining to the discussion, contrail-cirrus as clouds:

Induce a cloud-feedback, i.e. the coupling between cloudiness and surface air temperature.
Induce a radiative forcing, they increase the portion of the energy not re-emitted to space. The quantity is expressed in mW/m².

Increasing the air temperature has a link with increasing ground or oceans temperature, but the two notions mustn't be mixed. However cirrus are suspected to play a role in the global warming, because they could introduce a positive feedback into this warming.

Study: Coverage and effects of contrail-cirrus

Global radiative forcing from contrail cirrus published in Nature in 2011 was a study to evaluate the contrail-cirrus coverage, and its impact. Conclusion:

  Aviation makes a significant contribution to anthropogenic climate
  forcing. The impacts arise from [...] and from changes in cloudiness in the
  upper troposphere. An important but poorly understood component of
  this forcing is caused by ‘contrail cirrus’—a type of cloud that
  consist of young line-shaped contrails and the older irregularly
  shaped contrails that arise from them.

The estimated effect is depicted on this map (mW/m²) from the study:

Net effect of contrails (CIC) warming compared to other aviation factors of warming:

(source)

Study: Effect of contrail-cirrus on US climate

NASA conducted a study in 2004: Patrick Minnis, J. Kirk Ayers, Rabindra Palikonda, and Dung Phan -- Contrails, Cirrus Trends, and Climate.

This study was analyzed in Science Daily: Clouds caused by aircraft exhaust may warm the US climate:

  Using published results from NASA's Goddard Institute for Space
  Studies (New York) general circulation model, Minnis and his
  colleagues estimated contrails and their resulting cirrus clouds would
  increase surface and lower atmospheric temperatures by 0.36 to 0.54 degrees Fahrenheit per decade.

Aviation radiative forcing in 2000: An update on IPCC (1999)

This study was included in a new one by R. Sausen et al. in 2005. It shown the radiative forcing by aircraft could have been slightly underestimated:

Source: Aviation radiative forcing in 2000: An update on IPCC (1999) - R. Sausen

The US surface temperature is increasing by 1°C every 30 years: I would say this is very significant for plants, life, water cycle, oceanic currents, etc.

Also look at @Simon good answer about the increase of the difference between night and day temperatures, by more than 1°C, during the 3 days civil air traffic was forbidden on September 2001. This increase seems to confirm contrail-cirrus limit cooling on night time.


Is it possible to determine if winds were high without groundspeed, wind speed, AoA or AoS?

In the inertial (Earth) frame, denoted by subscript $_E$, inertial velocity ($\bf{V^i}$) is related to air velocity ($\bf{V}$) and wind vector ($\bf{W}$) as follows:

$$\bf{W_E}=\bf{V}^i_E-\bf{V_E}$$

Air velocity is more commonly expressed in the body frame (subscript $_B$), and is related to the inertial frame via the rotation matrix, $\bf{L}_{BE}$, as a function of the Euler attitudes ($\phi,\theta,\psi$):

$$\bf{V_B}=\begin{bmatrix}u \\ v \\ w\end{bmatrix}=L_{BE} (\phi,\theta,\psi) \bf{V_E}$$

$\bf{V_E^i}$ can be transformed from the ENU velocity to NED, and you mentioned that attitudes are measured, so that leaves the air velocity components.

If you have AOA ($\alpha$), AOS ($\beta$) and TAS ($V_T$) measurements, they are related to the components as:

$$\alpha = \tan^{-1}\frac{w}{u}$$
$$\beta = \sin^{-1}\frac{v}{V_T}$$
$$V_T=\sqrt{u^2+v^2+w^2}$$

That's three equations with three unknowns. At this point, you have all the information necessary to solve for the wind vector.

Without AOA and AOS measurements, your only hope is to assume some reasonable values of AOA and AOS. For AOS, you can assume 0 if there is no lateral/directional input. For AOA, you may be able to use some offline data (e.g. wind tunnel, CFD) if your weight estimate and aerodynamic data are trustworthy.

An additional note, per your previous question on finding AOA and AOS without sensors, you have a real dilemma here: you cannot obtain both winds and flow angularities without sensors!


What plane is this instrument panel from?

I was so close. I was looking at the de Havilland Otter but a mid 50s. A friend finally found it. It is a mid 70s DH-114 de Havilland Riley. Thank you verandaguy for leading to the de Havilland. That was most helpful. Now I can finish the Xmas present and be able to tell my Father-in-law the exact type of plane it came from. Cheers.


No, you can't say that the horizontal component of velocity is constant throughout the chord. There are few reasons why not:

1) From the formula you provided (which is correct if your assumption on velocity components is true for an aerofoil) we can see that as beta gets bigger the final velocity tends to infinity, which of course cannot happen.

2)The velocity change on aerofoil is dependant upon its pressure change, it reaches maximum at the point of maximum camber and not at the point of maximum thickness and I think that as per your theory it would than be reached at the point with maximum thickness.

3) Third and probably the most important thing is this: Lets imagine the flat plate aerofoil at some small angle of attack. The plate will produce lift, and the particles above an aerofoil will reach the trailing edge first. Since the airflow above aerofoil will be deflected by the same angle as below the aerofoil, by above stated theory, particles should reach the trailing edge at the same time because of a constant horizontal velocity. Which isn't true.

Second part of the question is correct, there is no net upward motion of air. In fact, there is a net downward motion of air behind an aerofoil called downwash. Basically how much the force wing exerts on air by deflecting the partincles down, by that amount of force the aircraft will be pushed up. Newton's third law.


How do wing tip vortices that interact with the wing surface affect drag?

MEng Aeronautics and Astronautics student at Southampton uni here. We've been studying this in some detail recently and I've found that MIT has released a set of lecture notes on finite wing theory, including a really useful document focussing on tip vortices and their impact on aerodynamic performance (http://web.mit.edu/16.unified/www/SPRING/fluids/Spring2008/LectureNotes/f05.pdf). This explains the induced drag acting on a wing/other lifting surface which is caused by tip vortices generating downwash, which in turn alters the wing's geometric angle of attack.
Hope this helps, or at least gives you a starting point for further research :)


That is the angle between true north and the current ground track. FR24 is slightly different to (most) aviation in that it uses true north instead of magnetic north as the datum.


There is any technical reason for the new Airbus shades?

It's not just for the looks. The A350 is the first Airbus ever to feature curved cocpit windows to reduce drag, and according to Airbus, the black "mask" contributes to ease of maintenance and harmonization of the thermal condition of the windows:

  "The perfectly curved shape of the nose helps the air flow hug the surface, in the least turbulent manner, thereby reducing drag. The emblematic “Ray-Ban” like black windshield eases the window’s maintenance and contributes to harmonising the thermal condition of this temperature-sensitive window area. ..."

Virgin Atlantic blog - Why does the Airbus A350 wear a Zorro mask?


Who has more power? Air Force One PIC or ICAO or FAA?

First, ICAO has no authority over aircraft movement in and of itself. It's a United Nations agency that, as Wikipedia puts it "codifies the principles and techniques of international air navigation and fosters the planning and development of international air transport to ensure safe and orderly growth." Individual sovereign nations accept whatever they want of what ICAO codifies, and it is the governing aviation authority of the individual nation that has the power.

Now, in the U.S., military aviation is not governed by the FAA, the civilian agency that for the most part complies with ICAO recommendations as do most countries. However, the U.S, government has a common air traffic control system for both military and civilian aircraft. If, for no good reason, an aircraft violates the air traffic rules, the FAA will deal with that for civilian aircraft, the military for military aircraft.

Air Force One is a military aircraft. Further, as @Zach Lipton has pointed out, it is a "state aircraft." Further, whichever airplane is carrying the President of the United States is designated Air Force One (or Marine One or Navy One) only when carrying the President, and the President is the Commander-in Chief of the military. I don't know how all that sorts out, but practical considerations dictate a general adherence to the "rules of the road" so to speak.

And finally, it's accepted practice that the captain of an aircraft is the final authority aboard the aircraft for the operation of the aircraft, regardless of who is aboard.

Better to rule by consensus than by diktat if there's time for consensus.


What is the purpose of the air inlets on an A320neo's pylon (LEAP-1A)?

It's not unique to the LEAP. You can find similar grills on the CFM56-5 and Trent 700, for example. That grill is the PCE's (precooler heat exchanger) air outlet.

Compressed (hot) air is taken from the engines (before combustion) for pressurization and air conditioning. This air has to pass through a PCE (cooled by air from the fan) before heading to the PACKs at about 200°C. The PCE is typically located in the pylon due to space constraints.

  CFM56-5 (A320) bleed users; source: slideplayer.com.br

The largest of turbofans don't have the PCE inside the pylon, and instead have them in the cold bypass stream (as shown below), as does the 737 due to its short pylon (or almost nonexistent pylon on the -3/4/500 series).

  Source: Boeing via leehamnews.com


What is the difference between a Boeing Line number and a Block number?

Here is Boeing's Examples

Block numbers

ZA001 Onwards - B787-8
ZB001 Onwards - B787-9
ZC001 Onwards - B787-10
ZD001 Onwards - rebuild of prototypes
ZE001 Onwards - B787-9 with customizations

Line numbers are the serial number of the aircraft of that aircraft type

Serial Number is the manufacturers serial (basically the number of aircraft they have built up to that aircraft)

Airbus doesn't use the Boeing Line/Serial numbers, they use a different system where the aircraft serial number is in fact the aircraft line number and the total # of the aircraft being built.


What is the best extinguishing agent when wheels catch on fire?

You can find some discussion in this thread but what you are looking for is

  Fire Service manual. Volume 2. Fire Service Operations : aircraft

  incidents Home Office - London

  HMSO, 12/99. Crown copyright 1999

  ISBN 0-11-341192-8; 0113411928

  5.4.2 Brake and wheel fires The overheating of brake and wheel assemblies usually follows excessive braking. This can happen on
  landing when a hydraulic failure reduces the ability of the pilot to
  utilise control surfaces (flaps) and he feels the aircraft may over
  run the runway or more often, on an aborted take-off. Quite often
  tyres will burst or, as the aircraft comes to a standstill, ignite by
  transference of heat from the brakes. To avoid metal failure,
  firefighters attending overheated brake and wheel assemblies should
  usually refrain from applying water and allow natural cooling. If
  there is fire however, a fine water fog applied from fore and aft of
  the undercarriage assembly is generally used.


Is there a set of laws which govern international flights?

International Airline is bound to follow the law of country of registration. Hence your flight limits you to dringking law in Abu Dhabi which is 18

Note some airline, Turkish here, have some policy not to serve alcohol on certain flights. On my experience with Hong Kong airline, the flight in-bound to Hong Kong only serve juices where out-bound had Tsing Tao :)

A not a really related topic but something more to read on travel.SE : Is it legal to drink your own alcohol onboard a plane over international waters?


How do the Airbus Beluga's wing/control surfaces deal with its high center of gravity?

As long as the aircraft flies without much sideslip, the vertical position of the center of gravity is not important.

It is a common misconception that the aircraft could "tip over" when banking due to a high location of the center of gravity, or even that dihedral would right the aircraft up because the lower wing will create more lift. This is all wrong!

To understand why, look where gravity is pointing in banking flight. By gravity I mean the total acceleration felt by the pilots and passengers, the apparent vertical direction.

A320 front view straight and banked with force vectors in the aircraft's frame of reference.

The force vectors in banked flight don't differ from those in level flight, only their magnitude grows. In both cases the apparent vertical is parallel to the vertical plane of symmetry and will go straight through the center of gravity, regardless of its vertical location. Therefore, it has no lever arm and produces no momentum around the center of gravity.

To put it another way, the aircraft banks in a coordinated turn to keep the apparent vertical in its vertical plane of symmetry, now that a horizontal force needs to be added to change the aircraft's angular momentum.

Therefore, neither the wing nor the control surfaces need any special adaptation to the huge fuselage. Only the vertical tail needs to be increased to compensate for the increased side area ahead of the center of gravity. In case of the Beluga, two vertical fins were added and the strake enlarged. This is a very common procedure for modifications of existing aircraft, because it is easier than designing a new vertical and improves handling compared to a new, scaled-up fin.

Side view of the Airbus Beluga (Picture source)

The fuselage has its aerodynamic center ahead of the center of gravity, so increasing its size will also increase its destabilizing yawing moment in a sideslip. This requires more stabilizing area at the rear, which can be kept relatively small since its aspect ratio is much higher than that of the fuselage, making it more responsive to sideslip angle changes. Both together will create a side force in sideslip which will be substantially bigger than that of an unmodified A300 in the same conditions. This sideslip-induced side force and the drag which comes with it will make the flying characteristics of the Beluga different to that of an A300. Since it acts quite a bit above the center of gravity, it will add a rolling moment, increasing the dihedral effect. I expect that it will be harder to build up a sideslip angle in the Beluga, and if the pilot crosses controls, the aircraft will slow down more quickly than a regular A300.

When designing the Beluga, it was clear from earlier planes (Super Guppy, 3M-T or BM-T Atlant) that the oversized cargo bay would not make flying impossible.

The 3M-T/BM-T modification for rocket stage airlifting. Picture source.


Is it always the case that any one STAR leads to all the runways?

Some STARS are designed for specific runways (i.e. not all runways for the airport).

For example, shown below is the BASET FIVE ARRIVAL to Los Angeles.  It is designed for runways 6L/R or 7L/R: (not for runways 24L/R or 25L/R)

page 1:

 page 2:


Are there any aircraft with retractable vortex generators?

Bell Textron filed a patent for retractable vortex generators in 2006. The patent is here.

Boeing also filed a patent for vortex generators that extend simultaneously with a leading edge slat here.


How can a CFI renew their certificate with the FAA during the government shutdown?

Short answer is no, but there is a way to renew your CFI while Federal Government is shutdown. However, it's not through the FAA because so long as the FAA is shut down it cannot process applications.

(After a few hours of freaking out at the thought of having to redo my CFII check ride, I discovered there is a solution to this.

While the FAA is not processing applications during the government shutdown, the FAA has authorized certain non-federal employees to accept and process airmen applications for CFI renewal AND to issue temporary flight instructor certificates. These are called Airman Certification Representatives (ACR), and are defined as:

  Airman Certification Representative (ACR). An ACR is an individual representing a specific FIRC provider who is authorized under Title 49
  of the United States Code (49 U.S.C.) § 44702(d) to accept airmen
  applications for renewal of a valid flight instructor certificate from
  successful graduates of that provider’s FIRC and to issue temporary
  flight instructor certificates

Source: Advisory Circular 61-83J.


What is this display on the 737 Classic?

The display you mentioned is the Universal Avionics MFD-890R. Page 15 of this document shows the screen in question. I suppose it comes with the new CDUs for a new FMS, as mentioned by Ralph J.

  Incorporating EFI-890R hardware in a single stand-alone Multi-Function Display configuration, the MFD-890R meets the needs of operators who want to incorporate additional capabilities in the aircraft like moving maps or charts, but have limited time or budget for an entire flight deck retrofit. The MFD-890R is fully compatible with the EFI-890R and can be used as part of a complete flight deck retrofit at a later time.


What exactly are these unusual flight code names that require ATC priority?

NIGHT WATCH / NAOC

Night Watch or Nightwatch is the program identifier for the USAF National Airborne Operations Center (NAOC), including at least certain Boeing E-4 flights.

NAOC (used in flight):

From JO 7110.65W:

  The term “NAOC” will not be a part of the call sign but may
  be used when the aircraft is airborne to indicate a request
  for special handling.

FLYNET

From JO 7110.65W:

  The code name “FLYNET” indicates that an aircraft is
  transporting a nuclear emergency team or a disaster
  control team to the location of a potential or actual nuclear
  accident or an accident involving chemical agents or
  hazardous materials. It is in the public interest that they
  reach their destination as rapidly as possible.

GARDEN PLOT

Classified. Related to operation Garden Plot. Presumably a callsign to be used by aircraft as part of that operation.

SCOOT

Term related to Special Air Mission flights in evacuation of government VIPs.

From JO 7110.65W:

  The term “SCOOT” will not be part of the call sign but may
  be used when the aircraft is airborne to indicate a request
  for special handling.

OPEN SKIES

Callsign for observation aircraft under the Treaty on Open Skies. The USAF aircraft used for this purpose is the OC-135.

From Wikipedia's Treaty on Open Skies:

  Observation/Demonstration flights are conducted
  under rigid guidelines outlined in the Treaty of OPEN
  SKIES that govern sensor usage, maximum flight
  distances, altitudes and priorities.


Is there a practical way to demonstrate sustained flight on the back side of the lift curve without an AoA meter?

Flight on the backside of the stallcurve is unstable; any (infinite small) increase in AoA will result in less lift. Less lift will cause the flightpath angle to decrease and the AoA to go up even more. To increase the lift, the nose has to be pitched down, but not so much that the stall is recovered otherwise you wouldn't call it sustained flight at the back of the AoA curve.

At the same time you are also on the backside of the powercurve. This means that any reduction in airspeed would cause the drag to increase therefore decelerating the aircraft furthermore.

This double unstable situation would require a lot of fast responses from the pilot, probably causing too high workload. I doubt if it is practically possible to fly on the backside of the liftcurve without special automation.


How are bids packages and awards generated?

This differs from airline to airline, at a large ME carrier the staff is divided in groups based on their personality. People from each group are randomly assigned to flights. Then there is a list where you're at a certain position, with each flight you take you move one spot higher on the list. The higher you are on this list the more they will take your preference for a flight into account. Lets say that this list has 7 positions, once you've hit the top you are moved back to the bottom of this list. Then with each flight you're going one step up in the list again. So after each 7 flights you have the flight of your preference. But say that you're almost at the bottom and file a preference for a very unpopular flight then you have a high change they will schedule you on that flight.