Is there any obvious warning when auto-pilot is disengaged or when the mode changes?

The Boeing 737 allows a mode called control wheel steering (CWS). The A320 doesn't. For what is CWS, see: Is it possible to disengage only one axis of a two-axis autopilot?

The wording on Wikipedia doesn't emphasize this point; however, the final report does.

  The pilots may also manually control the aircraft in a normal manner with the control wheel and column (control wheel steering [CWS]) without disengaging the pitch or roll axes of the autopilot system. Pilots can then assist the autopilot system in flying to a selected heading or course. Use of CWS does not disengage either channel of the autopilot system. The autopilot system was modified from the original design to allow for the use of GPS guidance for the course signals to the autopilot (section 1.6.10).

Note that Wikipedia says "(...) disengage from VOR/LOC mode (...)".

Therefore, for First Air Flight 6560, the autopilot was not disengaged.
Switching to CWS is not aurally annunciated. See also: Why are callouts of changes in the Flight Mode Annunciator not automated?
Autopilot disengagement is accompanied with aural and visual warnings. See: Why is an auditory alarm necessary when the autopilot disengages?

(All bold emphasis mine.)


Is there a way to integrate recorded digital media evidence into a pilot report?

No. PIREP's follow a strict format that predates that kind of digital media. They must be compatible with distribution via AFTN and ACARS. PIREP's are created from a limited character set, and there is no way to attach any kind of digital media.


What is the maximum altitude a skydiving plane can fly?

Qualifier: I am a master parachute rigger and taught sport skydiving for 10 years.

Standard jump altitude is 12,000 feet AGL - this is one turn of the standard parachutist's altimeter. This height provides 1 minute of freefall, is within reach of a Cessna with a decent engine and does not require supplementary oxygen. For most places, this means an operating altitude between 12,000 and 15,000 feet MSL.

Dropzones in high areas like Denver will reduce their jump altitude to 9,500 feet AGL mainly because the piston-powered planes take too long to climb higher and/or the upper part of the climb runs into the oxygen zone.


Was the Buran space shuttle capable of doing a go-around?

Unlike Space Shuttle, Buran could cary Saturn AL-31 jet engines. The testing version had four such engines and used to take off and then fly under own power during the tests. Hence it so should have been capable of go-around. The powered landing increased the safety of Buran in comparison to Space Shuttle (source).

Here it is possible to find the description of the jet engine system of Buran. This source names the engines as АЛ-31Ф (Su-33 has the same). It says two engines were foreseen for the space going version, and this would have not been sufficient to take off under own power. Each engine had the maximal thrust of 7770 kgf (afterburners were removed). The two extra engines of the take of - capable prototype were more powerful (12500 kgf).

The source also says jet that engines were not installed during the only space flight 15 November 1988 while there were non-functional engine controls in the cockpit. The engines were not ready yet.

Hence most likely the sources OP references talk about some go-around of the mentioned four - engine testing prototype, not about the go-around of the Buran returning from space.

The space going version of the Buran space shuttle was not capable of go around maneuver.


Is it possible to be a pilot for both the RAF and a Commercial company?

Basic officer training in the RAF takes 30 weeks, so you're already over your six months, even before you start pilot training.

When you sign up you enlist for a minimum period which varies according to your speciality. Six to twelve years is typical.
Source

Assuming you get through pilot training and make it to a squadron, you're not going to just sit around and wait for a war. There's ongoing training, exercises, active deployments and other duties that will take up your time. Whilst there will be periods where your working life will be 9-to-5, there will also be periods where you'll be working nights, weekends, public holidays, and away from home.

I don't know what the RAF policy on second jobs is, but for practical reasons I can't see that you would be able to drive buses for easyJet or the like.


Why does increasing thrust on one engine make the plane roll and not yaw?

Increasing thrust on the right engine only will make the aircraft yaw and then roll to the left.

The thrust does generate a yawing moment to the left, but the secondary effect of yaw is roll. In simplistic terms, a yaw to the left means that the right wing not only momentarily moves through the air faster than the left, but more of the wing is exposed to the airflow. This generates extra lift from the right, putting the aircraft into a left roll.

A more technical explanation of this effect can be found here.


Does the Boeing 737 NG have "5" radar altitude callout?

The Rockwell Collins EGPWS, that is probably the most widely used system (you can tell right away by the voice that sounds exactly like the character "Data" from Star Trek - Next Generation; I'd swear it's the same actor's voice) comes with the full range of callout altitudes/heights and airlines pick and choose which ones they want by "configuration strapping" settings (connector pin jumper configurations in the mounting tray) when the units are installed in the avionics bay.


It would actually miss the point of wind tunnel testing. A free flying model could only be subject to air stream in speed and direction so that the forces are balanced. A fixed model on the other hand can be subject to air stream of any direction and speed and the forces measured. It is important to measure the forces under those conditions too.


How does change in aircraft's weight equal fuel mass flow rate multiplied by 'g'?

In the SI system the weight is measured in Newtons [N = kg*m/s^2], while the mass is measured in kilograms [kg].
To convert kilograms in Newtons, i.e. a mass measurement in a weight, you multiply by the acceleration of gravity g.
In this case you're converting a change in mass to a change in weight, the conversion is the same, but both sides have an additional time component in the denominator due to the derivative.
Given your comment, it seems you're confused by the good old mass-vs-weight thing. Let's have Wikipedia:

In common usage, the mass of an object is often referred to as its weight, though these are in fact different concepts and quantities. In scientific contexts, mass is the amount of "matter" in an object (though "matter" may be difficult to define), whereas weight is the force exerted on an object by gravity. In other words, an object with a mass of 1.0 kilogram weighs approximately 9.81 newtons on the surface of the Earth, which is its mass multiplied by the gravitational field strength. The object's weight is less on Mars, where gravity is weaker, and more on Saturn, and very small in space when far from any significant source of gravity, but it always has the same mass.


How is paint embrittlement countered in high altitude aircraft?

There are 3 critical areas one may wish to address with paint:  the formulation of the paint, how it is attached to the substrate, and the properties of the substrate.

The substrate may expand, contract, bend or twist with heating, cooling, or stress.

The attachment of the paint to the substrate is crucial to durability.  Surface preparation includes cleaning, deposition of a chemical coating such as chromate, or primer.  This is a make or break step that should not be ignored.

Finally the paint itself.  Bare bones paint formula is solvent, pigment, and resin. The solvent evaporates, leaving the pigment (color or shade) and the resin, which is essentially the coating.

Factors such as temperature, flexability, hardness, weather and UV resistance must be considered.  The closer the properties of the paint are to the substrate the better.

I would find out what the airliners use.


It is certainly possible to build an aircraft using modern technology that is hard to lose. After all, aircraft have GPS receivers and passengers can watch YouTube in the cabin. All you have to do is integrate those two and send the exact GPS position to a ground station as frequently as you want.

However, the global aircraft fleet is not so capable. Some aircraft have satellite internet capability; some do not. For those that do, the internet connectivity is completely isolated from the aircraft navigation systems. (After all, you don't want any possibility that an aircraft in flight could be "hacked" by someone on the ground.)

Retrofitting an existing aircraft (which could be up to 40 years old or more) to add such capability would be a very expensive job. Retrofitting an entire fleet (with perhaps many different aircraft models) is astoundingly expensive. Existing aircraft navigation and communications systems are so good that losing an aircraft "almost never" happens (yes, it's happened at least twice this year), compared to the number of successful flights. The airlines probably consider upgrading their fleet to support this kind of continuous surveillance not worth the expense, when compared to the probability that one of their aircraft actually goes missing.


Is it a mistake or standard procedure to lit the landing lights only on very short final?

It is not an ICAO requirement to operate landing lights whenever you are below 10,000 FT. The mandatory aircraft lights you will see in regulations is strobe lights, nav lights and anti collision beacon lights.

It is standard operating procedure at several airlines to only turn on the landing lights when a landing clearance is received by air traffic control. This is most likely what you have observed. The landing clearance is usually given at very short final, and so crews will turn on the landing lights on very short final (unless you are in FAA territory, where multiple aircraft can be cleared to land on the same runway at the same time ...)


Can a US pilot residing in the EU fly N-reg under IFR on a US PPL?

Long story short, European residents apparently require an EASA license to operate a foreign aircraft, even if they also hold a foreign license from the country the aircraft is registered in.

European regulations are really difficult to pin down because implementation is delegated to member states, however it looks like as a resident in an EASA country you do need an EASA license to operate an N-registered aircraft based there. There are many online sources that say that, although they typically don't link to actual regulations. Several of them mention that you get a 12-month period to acquire the EASA license, during which you can still fly with your foreign license.
For example:
AOPA blog article:

The European Aviation Safety Agency, a pan-European regulator, had
passed a regulation some years earlier requiring that European
residents acquire a European equivalent license to fly an N-registered
aircraft in Europe. This requirement didn’t apply to nonresident
foreigners.

A UK Flight Examiner's website:

If your N-reg aircraft would be classified as an EASA aircraft if you
registered it under the G registration, AND it is based in the UK now,
you do need either an EASA licence to fly it or an EASA validation. If
you wanted to fly it outside the UK, you would need your FAA licences
too.

The underlying EASA regulation appears to be REGULATION (EC) No 216/2008, which says that it applies to foreign aircraft if the operator is based in Europe (Article 4, paragraph 1(c), emphasis mine):

registered in a third country and used by an operator for which any
Member State ensures oversight of operations or used into, within or
out of the Community by an operator established or residing in the
Community

Paragraph 2 says that the regulations apply to personnel too, it's not just about the aircraft itself:

[...] Personnel involved in the operations of aircraft referred to in
paragraph 1(b), (c) or (d) shall comply with this Regulation

The tricky part is that EASA leaves it to each member state to actually implement the regulations and sometimes they implement at different times (see comments in the AOPA article above). I couldn't find the Dutch regulations, but the UK regulations do confirm that only non-residents are exempt from European licensing requirements. Air Navigation Order, Article 149, emphasis mine:

This paragraph applies if the operator of the aircraft is neither
resident nor established in the European Union, and the person
acting as a member of the flight crew is the holder of an appropriate
licence granted or rendered valid under the law of the country in
which the aircraft is registered or the State of the operator.

(As an aside, the ANO article is written in a very confusing, double-negative construction, but it does line up with other sources.)
Because EASA delegates to each member state, the best way to get a definitive answer that applies to your situation is to contact the Dutch civil aviation authorities. When and if you do find out what the requirements are, it would be great if you would come back here and add your own answer to this question. There's surprisingly little definitive, sourced information available about this and a first-hand answer would be really helpful.


When should I notify ATC when I notice that I may have conflicting traffic?

I think you will find there isn't a correct answer for this, and that answers will primarily be opinion based.  That said, my opinion is that if you have ADS-B, be patient and let ATC do their job.

Speak up eventually, of course.  Especially if you see a clear converging path on your scope.  The 3nm you suggested seems like as good a point as any to mention it.

It's a little different if you are VMC.  In that case I might wait even longer and attempt to acquire a visual first.  That way your reminder to them can consist of your assessment of the need to deviate, or declare that you can maintain visual separation.


Where did the terms QNE, QNH, and QFE come from?

QNE, QNH, and QFE are Q Codes - the Q Codes are designed for telegraph (or radiotelegraph) use where information is transmitted in morse code and brevity is essential (e.g. "QNH KJFK 2992 INS" is much shorter to tap out in morse code than "JFK Altimeter 29.92 inches of mercury")

They are still used in verbal communication (radiotelephone), though much less frequently.
ICAO defines a list of standard Q codes for use in aviation (this site has a list).

Regarding the choice of Q as the prefix for these codes, this is to avoid confusion with station callsigns. The ITU currently will not assign prefixes beginning with Q to any country.
(There may be further historical reasons behind the choice of "Q", but I'm not aware of any.)


Why do some towers reference departures by compass direction, others by leg of pattern?

It depends on local custom.

Some airports have multiple runways, so controllers will use compass points instead of pattern legs, and this habit will carry over when they are assigned to a single-runway airport.

Other airports have noise abatement procedures which have specific names. Below are the departures for San Carlos airport, and pilots are expected to use a named departure, such as "Belmon Slough Departure" instead of "right-crosswind departure," and tower will readback the named departure.


Can you have TCAS RA if your other traffic only have TCAS TA?

If both aircraft in an encounter are equipped with TCAS and are operating in TA/RA mode, then both will receive a coordinated RA.  That is the RA will be coordinated between them using the Mode S datalink.

If both aircraft in an encounter are equipped with TCAS and one is operating in TA/RA mode and the other in TA Only mode, the one operating in TA/RA will receive an uncoordinated RA and the other will receive a TA. In an uncoordinated RA, the TCAS will provide guidance based on the observed path of the aircraft, modifying the RA as necessary.

If one aircraft in an encounter is equipped with TCAS and operating in TA/RA mode and the other in does not have an operating TCAS, but does have a transponder, the one operating in TA/RA will receive an uncoordinated RA.

There's a good guide to TCAS available from the FAA web site.


What are the flight rules for crop dusters?

14 CFR Part 137 regulates agricultural aircraft operations, with §137.51 discussing operation over congested areas, including:

  The crop duster must operate “with maximum safety to persons and
  property on the surface” and the crop duster must have obtained prior
  written approval from the FAA and notice of the intended operation
  must be given to the public. Further, the crop duster must submit a
  plan to the FAA that considers the flight obstructions and plans for a
  possible emergency landing.

Of utmost importance is the section regarding the flying of restricted category civil aircraft such as agricultural aircraft:

  Sec. 91.313 — Restricted category civil aircraft: Operating limitations.

  (a) No person may operate a restricted category civil aircraft— (1)
  For other than the special purpose for which it is certificated; or

  (2) In an operation other than one necessary to accomplish the work
  activity directly associated with that special purpose.

  ...

  (e) Except when operating in accordance with the terms and conditions
  of a certificate of waiver or special operating limitations issued by
  the Administrator, no person may operate a restricted category civil
  aircraft within the United States—

  (1) Over a densely populated area;

  (2) In a congested airway; or

  (3) Near a busy airport where passenger transport operations are
  conducted.

  ...

More information is available in this FAA document.


Are there any guidelines or regulations for seat legroom on airlines?

The short answer is no, beyond the need for an aircraft to satisfy the emergency evacuation requirements set by the FAA and other regulators. There must also be room for an approved seat cushion and seatbelts. So there is a point where a lack of legroom would impede evacuation to the extent that an aircraft couldn't pass the 90 second evacuation requirement, but there's generally no specific minimum legroom requirement.

The main exception is in the UK, which does have a form of minimum requirement (according to that link, the UK is the only country with one). The requirement is given as a different form of measurement from how airline seat pitch is normally defined, but the above link indicates that it basically translates to a 28-inch seat pitch. That's about as low as any airline goes, namely Spirit in the US. Most airlines draw the line at 30", with a few low cost carriers doing 29"


Turbo-fan idle at high speeds, will air speed up fan speed?

Yes, N1 should increase as the plane reaches higher speeds. This means that the blade speed will increase, therefore, increasing N1. Now because the engine setting is constant (throttle), this means that only a slight increase in the amount of thrust will happen.


Difference between Mach buffet and shock stall

Transonic buffet is caused by the separated turbulent boundary layer striking the airframe (horizontal stabilizer, wings, fuselage) with considerable force causing a high amplitude vibration, which physically shakes the whole aircraft. It's highly destructive and all commercial aircrafts should avoid entering a buffet boundary zone. That's why commercial transonic aircrafts are limited, not only by IAS, but also with Mach number as well. The reason for separated boundary layer is a shockwave formation on the airfoil which causes a great adverse pressure gradient and separates the airflow from the wing. The transonic aerodynamic buffet is an imminent warning to the shock stall. As the shockwave strengthens and separation becomes even more severe there will be a great change in coefficients of lift, drag and pressure. These changes will induce more drag, and due to the Cp changes on the airfoil it will cause mach tuck to occur. Mach tuck is a phenomenon which causes a nose down tendency of an aircraft and it is very difficult to compensate it only with the elevators. When all that occurs then we are talking about a shock stall. Shock stall is associated with an aircraft dive while transonic buffet is a warning sign to the shock stall and physically shakes the whole aircraft with a quite destructive force.


Do (did) powered airplanes exist where pilots are not in a seated position?

In the first ones the pilot was rarely sitting. Inspired by ships, some early aviators steered their craft by standing upright:

Almost all balloons were and still are flown standing upright. Same goes for all Zeppelins, and they should qualify as powered aircraft.
All Lilienthal glider designs required the pilot to stick the forearm through a tube and grab a horizontal bar, so his weight would rest on the forearm. Steering was done by swinging the legs left or right rsp. back or forward. The legs also doubled as the landing gear, much like in modern hang gliders. Lilienthal experimented with carbon dioxide engines, so some of his gliders can be called powered.
Gustave Whitehead's Number 21 design of 1901 was flown standing upright, but it is disputed that he actually flew it successfully.
The early Wright Flyers were flown in a prone position. Sitting came later.
The Santos-Dumont 14bis of 1906 was flown standing upright. Similarly to the Wrights, Santos-Dumont's later designs like the Demoisielle had a proper seat.

Santos-Dumont training to fly his 14bis (picture source)

The Horten gliders were flown in a prone position so the pilot would present a lower cross section. The Horten IIId was a motor glider version using a 32hp Volkswagen engine, so this should count as powered, too.
Before anti-g suits were perfected, some designs used a prone pilot position to increase the possible g loads. Here is an answer which covers this aspect.
René Leduc's ramjet-powered experimental aircraft used an almost lying position for the pilot to keep the cross section of the centerbody small.

Yvan Littolff in the cockpit of the Leduc 021 (picture source)

Most hang gliders use a prone or almost lying position for reducing the drag the pilot causes. The powered ones should also qualify here. Same goes for motor gliders derived from sailplanes, where the pilot position is almost lying, too.


Is there any instrument similar to a compass but which I can electrically drive?

Your best bet is to try and use an ADF readout, also known as a Fixed Card ADF (its most likely what you have pictured in your question). There are a few variants of the display out there and it will require some hacking to make it do what you need but it should suffice. As these units are generally considered "older" technology you may be able to get a read out for fairly cheap. On the even older side you can look for a Radio Compass/Radio Direction Finder which is quite similar.

Note: A heading indicator is NOT what you want. While you could pull one apart and install some kind of drive system to make it do what you want it is not, as it stands what you want.


Are US pilots permitted to carry & use their firearm in countries where guns are illegal?

Once you land you have to abide by the laws where you are. In the US federal laws (if there are any), when flying in US airspace.

Most US laws about airports and guns, only apply to the secured space. (Inside security), not the GA ramp or anyplace else.


First you will need to learn to decode the TAF's validity period.

TAF YMAY 022230Z 0300/0312 35010KT CAVOK
FM030800 31018KT 9999 SHRA BKN025 OVC100
INTER 0308/0312 31020G40KT 3000 +TSRA BKN010 SCT040CB
RMK FM030600 MOD TURB BLW 5000FT
T 23 24 28 33 Q 1012 1013 1014 1009

The validity of this TAF (in bold) is formatted as ddhh/ddhh.

  Validity period of TAF is from 0000 to 1200, on the 3rd day of the
  month UTC

From here we can see that it's valid for 12 hours.

Another example:

TAF COR YMLT 212240Z 2200/2218 31015G28KT 6000 -RA BKN010 OVC100
TEMPO 2209/2218 2000 +TSRA BKN005 SCT040CB
RMK
T 25 21 18 15 Q 1014 1013 1013 1011

  Validity period of TAF is from 0000 until 1800 on the 22nd of the month UTC

This one is valid for 18 hours.

You may check your country's AIP for how often they are updated.

For instance, in Australia, GEN 3.5 - 5 describes the routine TAF service based on airport size.

A International:  Issued 6 hourly, valid for 24 or 30 hours.
Commencement times 00, 06, 12 and 18 UTC.

B Large: Passengers > 150 000 or Movements > 75,000
Issued 6 hourly, valid for 12 or 18 hours. Commencement times 00, 06, 12 and 18 UTC.

C Medium:
Passengers > 50,000 or Movements > 10,000
Issued 6 hourly, typically valid for 12 hours.
Commencement times are 02, 08, 14 and/or 20 UTC, except in Western Australia where commencement times are 04, 10, 16 and/or 22 UTC.

D Small:
Aerodromes meeting passenger and movement thresholds, or other operational criteria.
Issued 6 or 12 hourly, valid for up to 12 hours.
Commencement times are typically 20 and/or 02 UTC, except in Western Australia where commencement times are typically 22 and/or 04 UTC.


Can private pilots run other non-passenger flight businesses?

According to the current FAA stance on the issue, none of it is allowed except glider towing.
The latest interpretation from the FAA that I'm aware of is the 2010 Perry interpretation, however, there was a conflicting letter (Del Rossi) from 1987 that said the opposite from the White interpretation.  The FAA further clarified the discrepancy between these two letters in 2010 with the Perry interpretation. (Note: this link contains both of those interpretations from 1987 and 2010 together.)
The FAA acknowledged the discrepancy in 2010 and determined that the older letter took precedence because it was issued by the national office, but the White interpretation was issued by a regional office, although on a later date.
For aerial photography and survey, if it is in furtherance of their own business and is simply incidental to that business, yes, they may perform the work as a private pilot according to the White interpretation.  The other interpretations, which take precedence say this is wrong.
If someone else hires them to fly so the passenger may do those things, it's definitely not allowed nor has it ever been mistakenly indicated as allowed by the FAA for private pilots in past interpretations.
There is the White interpretation from 1995 that incorrectly states:

To the extent that your operation would be in furtherance of your own
business of aerial photography or survey, and you are not carrying
persons or property for compensation or hire, then you may do so
holding a private pilot certificate. However, to the extent that your
operation would involve operating your aircraft as an aerial platform
for other photographers, etc., for compensation or hire, you would
need to be the holder of at least a commercial pilot certificate in
order to act as the pilot.

So, in short:

Do aerial photography/videography and charge for it? - No, but it was mistakenly allowed according to the White interpretation in 1995.

Do reconnaissance/similar and charge for it (aerial survey)? - No, but it was mistakenly allowed according to the White interpretation in 1995.

Deliver packages, or indeed cargo? - No, this would be carrying property for compensation or hire. See 61.113(a)

Drop skydivers - No, this would be carrying passengers for compensation or hire. See 61.113(a)

Pull up gliders for pay - Yes. See 61.113(G)

If you're actually planning on flying and making money somehow related to that flying and you aren't 100% sure you are legal, please ask an aviation lawyer in addition to online research.
If even the FAA managed to make a mistake on the subject, there's plenty of room for the rest of us to do so.


How is the cabin pressure maintained inside aircraft?

Once the airplane is closed up, all doors and windows secure, pressurization comes down to the following:

how much air is being pumped into the cabin?
how much air is being let out of the cabin?

Air enters the cabin (on a jet powered airplane) through bleed air taps in the high pressure compressor of the engines.  This air is routed through air cycle machines, or "packs" as they are commonly referred to.  The packs condition the air for temperature and humidity (typically taking all of the water out of the air) and then pump this air into the cabin at high pressure such that it is at the proper temperature after expansion to cabin altitude.

Air exits the cabin through outflow valves, which are typically at the rear of the pressure vessel.  These can be manually or computer controlled and will open and close to regulate how much air leaves the cabin.

To provide constantly fresh air, the incoming air from the packs is constantly supplied and as such the cabin pressure is almost entirely regulated by the outflow valves.  These valves have to be able to exhaust more CFM of flow than the packs can supply in order to let the cabin climb and when providing less CFM
than the packs the cabin will descend.

The cabin altitude will be managed so that:

it stays below a maximum pressure differential with the ambient atmosphere outside,
cabin altitude rate of change is limited,
maximum cabin altitude is kept below 10k feet (and typically below 8k feet) such that supplemental oxygen is not needed.


How are horsepower and standard displacement for a rigid airship calculated according to this book?

The book author just eliminated Hp from 1 by the formula 2.
$$ 15000 + 44(.39D^{2/3}) = .357 D$$
Do arthitmatic and rearrange:
$$.357 D -17.16 D^{2/3} = 42000$$
Divide by the .357 to get
$$ D- 48.067 D^{2/3} = 42016.8 $$
Then round off because he used a slide rule not a calculator.


Why does the auto brake panel on an A320 use "lo", rather than "low"?

Boeing 747 wiper knob showing LO; source: alamy.com

As shown above, it's not unique to Airbus, or to just airliners, so from that perspective:

Keeping the same standard as on-screen messages$^1$

Example A320 ECAM messages:

  CAB PR LO DIFF PR
  ELEC IDG 1 OIL LO PR
  FUEL CTR TK PUMP 1 LO PR
  FUEL L WING TK LO LVL
  HYD B RSVR LO LVL

Note: Messages on displays are abbreviated to save space, and are in all caps for readability (see: Why do aircraft cockpit displays use uppercase fonts?).

It wouldn't make sense to deviate just for the auto brake (its ECAM indication is also LO).

That labeling is also typically electroluminescent, so the fewer the letters the cheaper (not just for LO, not just for airliners).

$^1$: FAA AC 20-175 - Controls for Flight Deck Systems

  Labels are the most common means used to identify and describe controls and other devices in the flight deck. They can be full text (e.g., "Standby"), abbreviated text (e.g., "STBY"), acronyms (e.g., "AGL" for "Above Ground Level"), as well as icons (e.g., [icon example] for "On/Off").

  Control labels must be visible, legible, and understandable for the population of pilots that will use the controls, per § 2X.1555(a).

  Use only one abbreviation and/or one icon for labeling a function. This is to prevent confusion when a label appears in multiple locations. [emphasis added]

The AC also references SAE standard ARP 4105B Abbreviations, Acronyms, and Terms for Use on the Flight Deck (paywall), and ICAO Doc 8400.


what is the highest and lowest air pressure induced by an aircraft at supersonic speeds?

When an airplane goes supersonic, it creates a shock wave in front of it. The shock wave slows the air down to subsonic speeds, so the airplane sort of creates it's own cocoon of subsonic air to fly in.

When the air comes through the shock wave, it's speed reduces to below supersonic, and the pressure increases. The highest pressure is found behind the shock wave, in a stagnation point, a point where the speed is reduced to zero, like on the leading edge. The lowest pressure is usually found before the shock wave, this is the normal atmospheric pressure.

There are 3 types of shock waves:
https://en.wikipedia.org/wiki/Shock_wave
- the normal shock wave:
https://en.wikipedia.org/wiki/Normal_shock_tables
They have nice tables where you can see the speed, pressure and density behind the wave.
- Oblique shock waves:
https://en.wikipedia.org/wiki/Oblique_shock
These shock waves are called strong when the mach number after the wave is below 1, and weak when the speed after the wave is still supersonic.

NASA has some nice programs to show how different types of shock waves are formed and how they interact, you can find them here:
https://www.grc.nasa.gov/WWW/K-12/airplane/oblique.html


What are the limitations in adoptions of GTF (Geared Turbofan) technology?

The factors that are relevant here are:

Increasing the bypass ratio is very desirable in order to improve the efficiency of the engine, and for the same amount of thrust, this means increasing the fan diameter.
In order to keep the fan mostly subsonic, the fan rotational speed has to decrease with increasing fan diameters. Supersonic fan blade tips are possible and in use, but you lose efficiency and increase noise, so it's desirable to limit this to the outermost area.
For the same efficiency, a low-speed turbine requires more stages and therefore more weight compared to a high-speed turbine. Compare the PW1100G's 3-stage LPT (geared) with LEAP-1A's 7-stage LPT (not geared).
The only way to decouple the rotational speed of the LPT from the rotational speed of the fan is by using a gearbox.

In the long run, this is therefore a question of whether the gearbox is heavier than a slower-turning LPT and whether a possible increase in maintenance costs due to the gearbox is acceptable for the given gain in efficiency or reduction in engine weight. With further increases in engine bypass ratios, the gearbox becomes increasingly attractive.

In the short run, this is also a question of whether a company wants to risk developing a completely new component, with potential problems before and after entry into service. Additionally, with a given amount of money and manpower to develop a new engine, management will ask: Where are the engineering hours going to make a bigger difference, in improved fan, compressor, turbine and combution chamber designs/materials/... or in a gearbox design.

So while, for example, Rolls-Royce does not manufacture a geared turbofan right now, their "UltraFan" research engine project does include a gearbox. I think it's safe to say that it is only a matter of time until most commercial turbofans will include a gearbox.


why does the concorde's nose go up and down

When the Concorde is in supersonic flight, the shape of the fuselage has to be very aerodynamic.  On landing, the attitude of the plane is very nose high, so the nose comes down to allow the pilots to see the runway.


Why did the Beechcraft Starship use a delta wing?

Because it was something of a Burt Rutan trademark since his early days. His first designs, the VariViggen and VariEze, had such a wing already, and apparently he saw no reason to optimize the wing of the Starship.

Rutan VariEze in flight (picture source)

The only true innovation was a variable geometry canard, which he even patented. Being only 85% scale, the performance of the Starship prototype was formidable, but once the real production aircraft had been designed with full compliance to airworthiness regulations, the Beech Starship turned out to be less impressive. The additional wetted surface produced more friction drag. Piaggio's design is clearly superior.

By the way, the idea behind the variable geometry canard was sound: In the landing configuration it would balance the additional lift from the fowler flaps on the wing. But the whole mechanism cost more in weight than the reduction in drag during cruise could save.

Drawing from US Patent 4641800.


Which countries in Europe allow for the use of Pilot-Controlled-Light?

Sweden has numerous airports that use pilot controlled runway lights. Such lights are typically turned on by making a long (10 seconds or longer) transmission on the airport frequency, though variations exist.

Some examples of airports in Sweden that use PCL are:

ESSD Borlänge/Dala Airport
ESGE Borås
ESSU Eskilstuna/Kjula
ESNG Gällivare
ESSG Ludvika
ESKM Mora/Siljan
ESND Sveg
ESGT Trollhättan/Vänersborg
ESKC Uppsala/Sundbro

For clarity's sake: This answer is not meant to imply that other countries do not allow for PCL, nor that all lighting on the airports listed is pilot controlled.


Are canards useful for ultra low flying aircraft?

This highly depends on the overall conceptual design of the aircraft and there is no ideal configuration for any flight mission profile, except if you have very specific design constraints that will favor one configuration over another. In general, the trend when designing a wing of high aerodynamic efficiency, one that you would need for feasible human powered flight, is to have a traditional configuration of wing and empennage. This is for the wing to operate in clean air and not in the wake of the canard plane. Usually you focus on optimizing the wing and thus you want it to operate in its maximum efficiency.

A design example is the MIT Daedalus Human Powered Vehicle (HPV)

For further technical details regarding human powered vehicles and the their feasibility study you can start with this and discover further on your own.


Can a helicopter mask itself from radar?

Note that for advanced radar systems, moving helicopters might always be distinguishable from cars and other objects, due to the fact that helicopters have moving rotors.

While I have no information on military systems, I know the systems by robinradar can separate drones from birds by using doppler shift techniques.

Doing this on an actual, full-size helicopter without rotor guards should be a lot easier than on a drone.

This means avoiding detection by moving slow and staying low might not work, unless you can stay out of the line of sight of the radar system.


How does Kalman filtering work in inertial navigation systems?

A Kalman filter is used on all kinds of IRU's and INS's, even with airspeed information as in an ADIRU.  A Kalman filter is just a general method (and a very useful one) for state estimation and sensor fusion, which is exactly what's going on in an INS system.  I wouldn't call this "compensation". Inertial naviagation requires us to read in sensor values like angular acceleration, direction of magnetic north, longitudinal acceleration, and even airspeed, then convert those into more meaningful values like ground speed.  If done correctly, these processes (called sensor fusion and state estimation) will minimize errors on all the sensors you feed into it.   That's the quick version.  For a longer explanation of how it works, read on.

Kalman filters are used for sensor fusion and/or state estimation.  State estimation is when the basic physics parameters we want to know like speed and position (called the state of the system), are different from the sensor values we're getting, like magnetic compass readings and gyroscope values.  State estimation problems attempt to estimate these values like speed even in tricky situations like when errors are present or when the state can't be directly computed from the sensor values.  State estimation in Kalman filters can also take into account inputs to the dynamical system like airplane thrust and aileron position to try to improve the accuracy of the model, but this is not necessary and I'm skeptical about how often this is used based on my experience.

Sensor fusion, on the other hand, is when we want to combine several sensors to try and get a sensor that has the best of both worlds.  Sensor fusion and state estimation can overlap. A classic example is GPS and accelerometer sensor fusion.  GPS gives accurate position, but only down to a few meters and may not update at the rate desired. Accelerometers give accurate accelaration values even at small scales, but their position estimate tends to drift over longer periods of time.  By combining the two we can get the precision of INS but with no drift. One advantage of a Kalman filter is that the different sensors being combined don't need to be measuring the same values as long as we have equations for how the sensor values and the internal state are related.  For example, we can combine magnetic compass and gyroscope values even though the two aren't directly analogous. Sensor fusion can also be done with other methods like a complementary filter or Bayesian/Markov methods.

How does a Kalman filter work?  First a Kalman filter estimates the state (say, position and speed) using a system model to predict what the new position should be based on previous values.  This is the new predicted state.  The filter then looks at the sensor values to see what the new position should be based on those measurements.  It then reconciles the predicted and measured position to get a new position estimate based on the fact that both of those values may be inaccurate. The filter does this all including weights based on which errors in measurement and estimation are largest and which errors tend to be correlated with each other.  Note that this includes errors in both estimation and measurement: outside forces and inaccuracies in our model can throw off our prediction step just like bad sensors can affect our measurement step.

Technically the six degree-of-freedom equations often used for inertial navigation are non-linear (which is kind of like saying we can't scale, add, and reorder these transformations and rotations).   A regular Kalman filter will not work in this scenario and the Kalman filter must be a non-linear filter like an extended or unscented Kalman filter.

Kalman filters have several advantages over other filters like a complementary filter.  In elementary situations they can arrive at an identical solution to a similar complementary filter or averaging filter.  You mention tracking while predicting future values, and I'll explain why a Kalman filter helps.  If our last three positions were 1.0, 1.5, 1.7, and 1.8, a simple filter might average 1.7 and 1.8 or similarly try combine past and current values.  This would produce a lag behind the current value.  Kalman filters (and some simple filters) extrapolate previous values to predict the current value more accurately.  Kalman filters really begin to shine as the system we're trying to track changes in complex but predictable ways.

Simple filters like complementary filters struggle more than Kalman filters when errors are correlated or have different weights.  Kalman filters use weighting in their estimate to compensate for correlation in errors and also to give the most bias to the best sensor values.  For example, if angle of attack and airspeed tend to have the same inaccuracies at the same time, or if the gyroscope is much more accurate than the magnetic compass, the Kalman filter will give the sensors weights to compensate for that. If you're in a situation where you can model the equations of motion, or if you know something about the different types of noise in your system, the Kalman filter is probably more accurate than simpler alternatives.

Despite the accuracy of Kalman filters, I've seen a few places where simpler devices like complementary filters were used instead of Kalman filters.  Why?  The main reason is complexity, which I won't elaborate on too much at this point.


Why select the transponder to TA only in the case of engine failure?

The TA mode is selected when there is an issue, basically telling the 'other' aircraft that you cannot maneuver if a RA situation occurs. The other aircraft has to do all the maneuvering (as they can still generate RAs).
From Eurocontrol ACAS II bulletin from Dec 2012:

In the TA-only mode,the equipment still performs the surveillance function (i.e.  it  scans  for  proximate traffic) but it will only generate TAs. Other TCAS II aircraft can still generate uncoordinated  RAs  against  the  aircraft which has its TCAS II in TA-only mode.
The TA-only mode may be explicitly specified in operating procedures as a response to in-flight malfunctions such as an engine failure with consequent aircraft performance implications or a pressurisation system failure followed by an emergency descent.


Will dual-learning in a glider make my airplane learning safer?

Yes learn both, but... not at the same time.  As Dave says, there are too many differences to be absorbing simultaneously.  It's like a new airline pilot taking a type course on a Dash 8 and an RJ at the same time.  It'll burn you out.

If all this is a hobby activity in the first place with no urgent time lines, drop the power training for now and go take a glider course.  When you have your glider license, resume the power course (in most jurisdictions you get a bit of credit you can apply to the power license).

Absolutely no question that a power pilot who learned to fly gliders first, and especially if they became proficient in soaring, will be a superior power pilot.  Without the engine there, you learn fine motor skills, control coordination, energy management and speed control, and the ways of the atmosphere, to a degree that a power student doesn't and simply can't.  It also helps to remove a lot of the terror at the thought of dealing with engine failures.  I learned power in 1975 and gliders in 1993, and wish I'd started on gliders first.

And you may just discover that soaring is the sport for you.  You have to try it and get into it, and experience the incredible rush of climbing at 500 fpm in a thermal without an engine, that you found by trolling the sky, or spotting a hawk and joining him (and seeing him just look at you and carry on as if you weren't there), that may be a struggle to stay in or may be an easy elevator ride, maybe for 30 minutes in the air or 4 hours. No two flights are ever the same.  The private owners at my club, on a good day, launch at noon or a little after, and come back at 3 or 4 or 5 pm.

Power flying is mostly enjoying operating a machine that takes you from A to B, or to go sight seeing, in really fun and novel way.  Soaring is flying as pure sport; a game you play with the atmosphere. Like sailing a catamaran times ten, vertically.  It may not be for you, but if you get into the game, it's like nothing else and it's worth going to find out.

Plus since you're aviating largely on solar energy and at non-profit clubs the instruction is free, it's somewhat cheaper lol.


Is there a more specific term than 'flight line' for straight lines flown during flight?

Although my aviation knowledge is not all encompassing, I would argue that you, your boss, and your software company may want to know your audience as well as possible. The same terminology can mean different things to different segments of society. For instance, uncontrolled airspace/airfield would mean something totally different to a pilot than it would mean to the media or general public.

A quick search of the Federal Aviation Regulations/Airmen’s Information Manual, the Pilots Handbook of Aeronautical Knowledge , and the Airplane Flying Handbook only garners results describing specific areas of an airfield and the personnel working there. My experience in civilian aviation and in the military is consistent with this usage. When pilots, ATC, and others in the aviation field describe an aircrafts path, they use terms such as the following:

Route
Return route
Round-robin route
Great circle route
Flight path
Leg
Direct leg
Course
Direct course
Track

The term you are probably looking for is Transect pattern consisting of transect lines.

Someone more knowledgeable might have a better term.


What is this 'runway number' automatic readout system on a flight deck?

That's indeed the plane. It's equipped with a RAAS (Runway Awareness and Advisory System).

It also provides other call-outs, such as remaining runway length, approaching a runway, being on a runway, staying for too long on a runway, among others.

It is indeed a safety system, to make sure runways are not mixed up, and awareness of being on a runway in low visibility, for example. It is not standard on all planes, for example from the linked article:

  In 2015 the largest European low cost carrier Ryanair announced it would equip their entire fleet by the end of 2016 with RAAS as an investment in its commitment to safety.

The system does not require airport equipment, it requires a software update to the plane's EGPWS and the on board GPS. If an airport is not in the EGPWS database, such as some of the infrequently used GA airports, the system won't be able to call-out the runways.

The system was certified in 2007, but I haven't been able to confirm the entry into service date, but it's been around for a while. According to the Wikipedia link, Alaska Airlines introduced it in 2008.


Can a controller clear you through an SFRA?

An AOPA article on this has a chart of the Leesburg Maneuvering Area (LMA) which, as you said, doesn't require a DC SFRA flight plan (you do need one for pattern work, though):

If you compare the area in the chart to the flight path in the image in your question, it looks to me like Joe entered the SFRA southwest of JYO and then entered the south edge of the LMA. I suspect the FAA is saying that he should have flown further north, then entered the LMA from the west. In other words, he cut through a corner of the SFRA. I've marked that in red here:

The LMA NOTAM says:

  PILOTS MUST ENTER THE LMA VIA THE MOST DIRECT ROUTE AND AVOID ENTERING
  REST OF THE DC SFRA

By cutting the corner, Joe entered a part of the SFRA that was outside the LMA, hence the call with the FAA. That's my interpretation, at least, although I'm surprised that the FAA didn't spell out to him very clearly what the issue was.

And to answer the question in the title, ATC cannot clear a pilot to do something he isn't authorized to do. ATC could clear a student pilot into class B airspace, but if the student doesn't have a logbook endorsement for that airspace then he still isn't allowed to enter (barring emergencies). "Proceed direct Leesburg" doesn't mean "fly in a straight line to Leesburg regardless of other considerations", the pilot still has to get there legally.


Do different types of missiles indicate different lock tones to the pilot?

Lock tones are normally used for (surface/air)-to-air infrared homing missiles. Air-to-surface missiles don't "growl".

The tone is used to indicate missile readiness and quality of lock, not the type. Phantom pilots in Vietnam used to cycle between all available Sidewinders to check which seeker had the best tone then put the worst one to be last in the firing order (source: "Sierra Hotel : flying Air Force fighters in the decade after Vietnam" book, page 12)

At first there was a volt-meter in the cockpit to do that, but during development testing they figured out looking inside the cockpit in a dogfight to check if the missile is ready to fire wasn't a good idea, hence the tone frequency was introduced (source: Fox Two).


What does "composite panels on a frame" mean?

Traditionally, aircraft are built of frames (analogous to a person's skeleton), as shown below, and the smooth outer skin of the aircraft consists of panels fixed to these frames.  There are many frames and, for example, the small size of the windows is because they have to fit between the frames.

Image source: Wikipedia

The A350 uses this traditional construction, except the frames and panels are built of composite materials (carbon fibre reinforced plastic), rather than aluminium. However, the fuselage of the Boeing 787 seems to consist of a composite "tube", with reinforcing ribs running the length of the plane. There seem to be many fewer "ribs" running around the fuselage in this design than in traditional ones.

Image source: Wikipedia


How does a fuel tank fire self-extinguish in an A380?

The Australian Transportation Safety Board's Final Report gives a couple of possible reasons that the reaction was not sustained in Appendix D on page 257:

  The flash fire initially consumed the oxygen inside the tank; reducing the oxygen concentration level to below the threshold required for sustained combustion of Jet A-1.
  The general temperature rise associated with the initial combustion was low and insufficient to increase the temperature of the fuel inside the tank to at least the lower flammability limit of Jet A-1. Quenching of the flame by the cool fuel tank walls (evident from the sooting) and the entry of cooling air through the tank perforations may have promoted this.

Note that Jet-A requires quite a bit of activation energy to vaporize and burn. If the burning of what fuel did burn didn't produce enough energy to provide activation energy for the surrounding fuel, the fire would not be sustained. The fire was likely very brief as the turbine disc fragment passed through the tank.

From what I've heard (I haven't tried this myself,) you can drop a lit match in a bucket of Jet-A and it won't ignite. Using fuel that doesn't easily burst into flames in a vehicle designed to carry tens of thousands of gallons of fuel at several hundred miles per hour is desirable and intentional for obvious reasons.

To illustrate just how hard it is to burn Jet-A, the fuel tanks in Asiana 214 never ignited. The entire fuselage was burned out, but the fuel tanks never burned.

Remnants of Asiana 214's hull Source: Wikipedia


Who bears responsibility when an aircraft takes off from the wrong runway?

It depends. There could be any number of reasons for such a mistake, and it is rarely the mistake of any one single person.

Within aviation, we don't really talk about responsibility the way you seem to imply in your question. In many other industries, when a mistake happens, an investigation  is initiated with the purpose of finding and punishing the responsible party. In aviation, it is believed that no one makes mistakes on purpose; if a plane takes off from a wrong runway, no one meant for it to happen.

So accident and incident investigation in aviation does not focus on finding someone responsible. Instead, the investigation focuses on figuring out how a similar incident/accident can be prevented in the future. That is why ICAO Annex 13 says:

  The sole objective of the investigation of an accident or incident shall be the prevention of accidents and incidents. It is not the purpose of this activity to apportion blame or liability

If someone takes off from another runway than intended, the investigators will not just look at who made the mistake, but rather why the mistake was made. There could be any number of reasons for this. Very often, there are hidden latent threats somewhere in the system.

Maybe the lights at the airport were not sufficient, maybe the signs guiding the aircraft to the runway were misleading, maybe the taxiway layout is confusing, maybe the ground radar was inoperative when it should have been working, maybe the airline had scheduled the crew in a way that imposes fatigue in the cockpit, maybe the procedures are insufficient - I could go on.

The point here is, these potential causes are all things that can be changed in order to prevent the same incident from happening again. You can put up better signs or repair the ground radar, etc. Whereas, if you simple decide that the pilot or controller is to blame and then fire them, without removing the latent threats, then it's more than likely that another pilot or controller will make the same mistake in the future. What are you going to do then - fire them as well?

The whole idea is, instead of focusing on punishing people for their mistakes, if you try to understand what caused them to make those mistakes, you will not only learn much more, but you will also encourage people to report more incidents, that may not otherwise have been reported. We call this Just Culture, and it is all part of the reasons why aviation remains to be one of the safest ways you can possibly travel.


Do pilots lose their licenses following a gross misdemeanor conviction?

The most important thing to say here is that the only way to get an answer for a specific case is to consult an aviation attorney. Don't rely on any answers you get here!

Having said that, the general answer (that may not apply in every case) is that the FAA is primarily interested in alcohol and drug actions and convictions, including driving offenses and drug transportation. Pilots have to report those per 14 CFR 61.15, and again in any future application for a medical certificate:

  Do I have to report anything other than alcohol and/or drug related
  convictions?

  Yes, under 14 CFR Part 61, you must report alcohol and/or
  drug related administrative actions, whether a conviction took place
  or not. Arrests, administrative actions and convictions are also
  reportable under Part 67, the airman application for a medical
  certificate.

AOPA has a good explanation of the reporting requirements and their Pilot Protection Service can help with medical and legal issues. But it isn't a foregone conclusion that you lose your certificate, at least in 'simple' DWI cases:

  A single driving while intoxicated (DWI) arrest, conviction and/or
  administrative action usually is not cause for denial provided there
  are no other instances or indications of substance dependence or
  abuse.

Leaving aside alcohol and drugs, if the misdemeanor had nothing to do with aviation then it's unlikely to come within the FAA's scope. There might still be some odd theoretical possibilities, like if the misdemeanor conviction attracts the TSA's attention and you're flagged as a security risk (see 14 CFR 61.18) but that's just playing with 'what if' scenarios. Again, you need to consult an aviation attorney for advice on specific cases.


How does yaw relate to pitch?

There are four forces at play on a single engine aircraft that can cause turning tenancies or Yaw.

The main reason a single-engine propeller aircraft yaws left at T/O is due to  Asymmetrical Thrust (P-Factor). At high angles of attack the right side of the propeller disc creates more thrust than the left side and this causes Yaw to the left.

Gyroscopic Precession causes a yaw to the right when an aircraft is suddenly pitched up(tail is lowered or nose is raised) and a yaw to the left when an aircraft is suddenly pitched down. (tail is raised or nose is lowered).
This force is only apparent while the aircraft's Pitch is changing, once the pitching action is stopped, the force is gone. (not present in a steady nose up climb)

Slipstream effect causes a slight yaw to the left, and slight roll to the right.

Engine torque causes a roll to the left.

Most single engine aircraft today have a clockwise spinning propeller. All these forces would be the opposite if it were a counter-clockwise spinning propeller.

A more detailed explanation can be found here: Turning Tendencies


How can I calculate ambient air pressure from flight data?

It kind of depends on how accurate you want to be because you could start asking about instrument errors and position errors and stuff like that.
But, assuming you don't want to get into that...
The link you included would indeed show a standard atmosphere pressure but the pressure altitude data you have is also referenced to the same standard atmosphere (it actually depends on the setting of the altimeter... if it is set to 29.92 / 1013 mBar then you're in luck).
Ori


An aircraft doesn't need an AOC    Operating the aircraft for anything other than for private purposes is why you need one.


For a coaxial rotorcraft, Do horizontal and vertical stabilizers in the tail really make much of a difference?

The horizontal tail surface is there to generate downforce that holds the nose up in cruise. Without it, the faster you go, the more the nose points down as the machine's body wants to "trail" so to speak behind the tilted rotor disc.
The vertical tails are to provide a weathervaning effect to make the machine passively point ahead in forward flight without requiring a torque control input.
Take those surfaces away, and you are stuck with pointing down at an unpleasant angle while cruising, and having to constantly work the pedals to keep it pointed straight. A fly by wire yaw stabilization system working the pedals in the background could probably take care of the yaw part, but I don't know how you could deal with the pitch part without a stabilizer surface.


From this cockpit picture I cannot identify this aircraft. Any ideas?

That is the cockpit of the Shuttle Training Aircraft, a modified Grumman Gulfstream II. Here is higher resolution picture:

(Wikipedia)

The STA is a "highly modified Gulfstream-2 aircraft," Nickel said. The plane’s cockpit has been adapted to closely resemble a Shuttle's flight deck; the left-hand seat features the same hand controls that a Shuttle commander uses during a mission. Several passenger seats in the back of the aircraft have been replaced by a bank of Shuttle-simulating computers.

(NASA)
They could simulate the glide of the Space Shuttle by flying with the main gear lowered and reverse thrust in flight:

In order to match the descent rate and drag profile of the real Shuttle, at 37,000 feet (11,300 m), the main landing gear was lowered (the nose gear stayed retracted due to wind load constraints) and engine thrust was reversed. Flaps could be deflected upwards to decrease lift as well as downwards to increase lift.

(Texas Air and Space Museum)


Is there a common maintenance issue requiring filling a hole in the tail on the A321?

While maintenance records exist at the airline, they're not something that can be accessed by the general public over the internet.  And without those records, it would be guessing to answer what exactly "filled a hole with putty near the tail of the plane" was addressing.

It sounds like the delay might have been to allow the putty to cure, but again, without knowing the exact details, that's as much a guess as anything.

If you know somebody who works in the maintenance department at AA, they might be able to get the info, but again that's not the sort of thing that airlines like being released routinely.

This question may well be closed as being essentially unanswerable, and that's probably the right "answer" in this case.  Without far more specific knowledge, it's not something one can determine from the facts given, even with the World Wide Web available for further research.


Is there a best-practice method to work through a checklist?

The current FAA Advisory Circular dealing with SOPs in general, but only lightly touching upon checklists, is AC 120-71a. It is primarily aimed at Part 119 certificate holders who conduct operations under part 121, but is also recommended for operations under Parts 91, 125, and 135. It also changes the wording from Pilot Not Flying (PNF) to Pilot Monitoring (PM) in order to reinforce the idea that he or she is not just a passenger with a better view, but an integral part of the flight crew.

With respect to actual checklist usage, to the best that I've been able to find, the FAA does not issue a hard recommendation (air carrier checklists and procedures have to be approved by the FAA prior to certificate issuance anyways), but it does identify two primary methods of checklist usage: Challenge-Do-Verify (often used for abnormal and certain emergency procedures) and Do-Verify (often used for normal and time-critical emergency procedures), which relies on memorized flows followed by verification with the use of a checklist.

A 1995 Study issued by the FAA weighs in on the pros and cons of the two methods and surmises that, when used properly, the CDV method is less likely to result in missed items, but does allow for the fact that, in operational usage, pilots may batch items together, thus defeating the purpose of the systematic, step-by-step approach of the method.

Stepping aside from the multi-crew environment, where having someone with the checklist in their hand and reading things off one by one can work quite well, my personal observation has been that, in a single-crew environment, pilots who rely on a CDV-like method (sometimes known as Read-Do) are more likely to end up falling behind in configuring their aircraft than those who use DV-like methods, assuming of course that the pilots actually know their flows and perform the verification properly (as in actually verify that everything is as it should be rather merely reading items off the list and trying to remember if they've accomplished them).

Lastly, with respect to the 'checked' vs. verbal confirmation of status, this is usually dependent on how critical and laborious the status confirmation is. An example would be with altitude setting verification, where it is not uncommon for the procedure to call for the PF to set the new altitude in the Mode Control Panel and, while pointing to it, call out the new altitude, which is then verbally confirmed by the PM. Every operator's experience and demands will be different here, but a number of best practices are recognized and the folks at the FAA, NBAA, FSF, AOPA, and many others are doing their best to publicize and promote them.

See here for the FAA's Industry Best Practices Reference List.

The checklist you've provided appears to be intended for multicrew operations. In this particular case, what would happen if the CDV method was to be used is that the Pilot Monitoring would read the items off one by one and the Pilot Flying would execute accordingly, verbally acknowledge doing so, the PM would quickly verify compliance and move on to the next line item.

In a DV environment, the Pilot Flying would go through the flow, and call for the checklist, at which point the Pilot Monitoring would begin to read off the items, and the Pilot Flying would verify that they have been complied with.

The line items that have BOTH in them are meant to be a special emphasis case in that both crew members are required to verify that the line item has been complied with, regardless of method used.


Are there US guidelines on how aviation is handled during an emergency situation?

Given the scenario described, this is highly speculative but I'll have a go anyway.

I assume that FEMA would be responsible for the overall evacuation and indeed their transportation annex says that the FAA's main responsibility in an emergency is limited to airspace management:

  DOT/Federal Aviation Administration (FAA) is responsible for the
  operation and regulation of the  U.S. National Airspace System,
  including during emergencies.

The same document appears to rule out military control of US airspace (my emphasis):

  Under certain conditions, DOT/FAA may delegate  use of specified
  airspace for national defense, homeland security, law enforcement, and
  response (e.g., search and rescue) missions, but retains control of
  the airspace at all times.  DOT/FAA may also implement air traffic and
  airspace management measures such as  temporary flight restrictions in
  conjunction with these missions.

In practice, the main thing the FAA would do is to set up one or more (possibly very large) Temporary Flight Restrictions to ensure that only emergency and evacuation aircraft could use the airspace around the affected area (see 14 CFR 91.137). In the catastrophic scenario you described, it might be serious enough for the FAA to close the entire national airspace system to non-emergency traffic - as they did on 9/11 - because the refugees would presumably have to be taken all over the US and the evacuation would be a genuinely national crisis.

Apart from that, the FAA could provide extra ATC services by calling in controllers from vacation and/or making them work overtime; they would probably also have to implement some quick procedures to manage the increased air traffic in the area. They could waive or suspend rules on crew working hours, required aircraft maintenance or anything else that would reduce the amount of time that evacuation aircraft could spend in the air. Of course all these things would increase the risks involved in operating the aircraft, but in the face of an unavoidable disaster that would presumably be acceptable. Anyway, I guess no one would prosecute a pilot for flying overtime to save lives in such an extreme situation.

Mobilizing GA aircraft for the evacuation is another possibility (an aviation equivalent of the Dunkirk evacuation) and the FAA could help there by setting up temporary ATC procedures, creating ad hoc control towers at smaller airports and so on.

The FEMA document linked above implies at least some planning has been done with the FAA on disaster response:

  DOT/FAA Response Cells: FAA activates specialized response cells to
  manage and  coordinate air navigation services and other
  aviation-related efforts.

But what FEMA and the FAA would really do in a specific situation is very speculative and has much more to do with disaster response than aviation: the aircraft are just there to move people and things around, and the real challenge is deciding how to use them.


Is there an official English version of LTF-UL?

For LTF-UL 2019 there is no official English translation, unlike, say, documents from the United Nations or the Vatican.  German aviation forums have plenty of statements like

Ja eine offizielle englische Übersetzung gibt es tatsächlich nicht

But the document's language is technical and precise enough that Google Translate can manage it accurately.  Here is the translation, as .txt (as HTML, something weird happened).  http://camille-g.com/tmp/LTF-UL-english.txt


Practice Pans - are there any genuine reasons not to use them?

I presume you are from UK since it is the only country I know of that uses practice pans.

Basically, ICAO (ICAO Annex 10, Volume V, § 4.1.3.1.1) states that the emergency frequency 121.5 MHz (sometimes called "guard") shall be used only for genuine emergencies. So typically any other use is considered misuse.

However, countries can file deviations from this rule and publish these deviations in their AIP. One such example is the UK, where 121.5 can be used for practice PAN calls to ensure pilot familiarity with the process.

Pilots not familiar with the situation in the UK sometimes frown upon this use, and as you mention, jump in with the dreaded "transmitting on guard" sentence. But those doing that seem to have the same reaction when a real emergency is going on.

If you are flying in the UK and want to practice an emergency situation you are encouraged to do so by the D&D cells. But remember to ask permission first:

  A/C > London Centre, callsign, request Practice Pan

If they have the time to accommodate you, the reply will be something like

  London > callsign, Practice Pan acknowledged, continue when ready

And remember, it is not only a practice for you, but also for controllers. There is a benefit for everyone flying around.


What are L/D ratio of famous WWII fighters?

Please find the answers below from "World war II fighter aerodynamics" by David Lednicer.

And L/D, of course, depends on the CL you are flying at but you can easily calculate it from the unambiguous drag area given

Edit: Calculated L/D vs speed curves below for 4000m altitude flight. A fixed span efficiency was taken to simplify the calculation. Please consider this as an approximation only


Why is the force that moves an airplane forward called THRUST and not PULL?

Thrust is the force reaction from accelerating a gas from here to over there.  If the element creating the thrust, a propeller, is in front of the engine, it's called a "tractor" configuration because it's pulling the engine, like a tractor (any normal front engine airplane).  If the prop is at the back, or more correctly, behind the engine, it's a pusher configuration (A Lake Buccaneer amphibian is a pusher even though the engine is amidships, not at the tail, because the prop is on the back of the engine itself).  Lots of other designs have put the prop all the way at the back.

In a jet engine, you don't really have an element pushing or pulling the engine itself because the thrust reaction is actually happening inside the engine, mostly in the area ahead the convergent nozzle of the tailpipe where the flow is forced to accelerate. So for jet engines it's just thrust.


Why does this NOTAM make me think GPS is unavailable?

This outage is due to department of defense GPS interference testing taking place 17-18 Nov 2015.  The interference generated may make the GPS signal unreliable and the outage cone described by NOTAM lets you know that you can't trust the GPS signal during this time.  This interference may be purposeful jamming or live testing of devices that may interfere with GPS to ascertain what level of interference occurs.


Are helicopter pilots required to use GPS navigation?

No, pilots are not required to use GPS maps or moving GPS while flying helicopters or fixed-wing aircraft.

There are some approaches to landing that require GPS (called RNAV) approaches, but the airports that they serve usually have other types of non-precision approaches as well.

Helicopters have specialized maps that are called Helicopter Route Charts that are supposed to provide additional information relevant to helicopter pilots. These charts may be carried in paper form, although newer aircraft also have them as electronic moving maps. The pilots may also (but are not required to) be using electronic flight bags with moving maps/terrain/synthetic vision.


Why is the landing distance increased on grass runways?

The long and short of it is that wheels are designed for smooth tarmac. While grass increases friction on the wheels on takeoff (making the aircraft work harder to get up to speed), it also reduces the efficiency of the brakes, thus taking longer to slow down.

And to add to @GdD's point, grass retains moisture much better than tarmac, so in wet conditions it is considerably slippier (and will remain so for longer afterwards).


What is the optimal wing sweep angle for a passenger airliner?

Generally, sweep makes the wing less efficient in creating lift and complicates structural design. Therefore, aircraft designers try to use as little sweep as they can get away with. However, sweep delays the onset of compressibility effects and allows jet aircraft to improve their maximum transport performance (the product of speed and payload).

Forward and backward sweep both help to fly faster, but backward sweep is preferred because it makes stalling less dangerous, improves directional stability and allows to make the wing lighter. The shortest take-off distance will be achieved with zero sweep - if it were not for the need to limit compressibility effects, sweep would only be used in tailless aircraft.

The main factor for choosing wing sweep is the desired cruise Mach number, and Mach 0.85 has become the de-facto standard. Other factors are:

Relative wing thickness: A thicker wing needs more sweep, because thickness adds its own compressibility effects.
Maximum local Mach number of the airfoil where recompression is shock-free: So-called supercritical airfoils help to reduce sweep, and older designs (before the A310) had generally more sweep because their critical Mach number would had been lower at equal sweep.

Regulations have nothing to do with it, only engineering determines the sweep angle. Since the design cruise Mach number is quasi-fixed at Mach 0.85 for long-range airliners, the sweep angle of different aircraft is very similar. Regional jets normally fly a little slower to improve fuel efficiency, and their sweep angle is less than that of their big, long-range cousins.


Are the Boeing MCAS and Airbus Alpha Protection systems the same?

No, the two systems are completely different.

The MCAS of the new Boeing 737 MAX was introduced to help the pilots lower the nose in high angle of attack situations by applying down stabilator trim. This was necessary because the engines are mounted further forwards compared to the previous NG models.

Note: We do not know whether or not MCAS caused the recent crash in Ethiopia yet, it is a bit premature to jump to conclusions now!

The Alpha Protection on Airbus aircraft is part of the fly-by-wire control (What is the Alpha protection?) and will limit control inputs from the pilots instead of applying trim. This is very different from how MCAS works.


DO-254 and microprocessors: how does it apply?

DO-254 is for Airborne Electronic Hardware. Redundancy isn't necessarily required for DO-254. I would expect that the processor manufacturer would be able to provide a data package with the necessary documentation if a company were to use it in a DO-254 certifiable product.

In my experience, however, DO-254 is applied for custom micro-coded components only (for the FAA at least). DO-254 was a way to apply concepts similar to DO-178 to things like PLDs, FPGAs, and ASICs to prevent a "firmware" gap in certification.


Does a decreasing shape factor correspond to greater or reduced probability of separation?

Yes you're reasoning is spot on. As the momentum thickness decreases, that indicates the velocity gradient at the wall is less, indicating a greater likelihood of separation occurring.


How does an aircraft recharge its batteries?

The engines turn generators which supply the electrical power to the aircraft, including a battery charger that keeps the battery at 100%.  (Normally, power coming "from the battery" on the diagrams, is actually coming from the battery charger or another component like a Transformer-Rectifier converting AC to DC current.  The battery is very rarely actually being drained in flight.)

If you had an aircraft battery & went to deplete it with USB devices, it would take a lot of them & a really long time.  Aircraft batteries store power way beyond what our normal cell phones & iPads do, and can power all the emergency systems on the jet for an hour or more (radios, INS, flight instruments, minimal lights, GPS, flight management system, etc).  Of course, if you're down to just the battery, in-flight entertainment is NOT one of the systems being powered!


Aircraft pilot's seats: what is the notch for?

It's either for clearance of the column of the yoke or moving the crotch strap of the harness closer to the body of the pilot.

Alternative yoke designs remove the need for the notch:

(source: airliners.net)

Alternative control methods like the Airbus sidestick also remove the need. As Henning Makholm noted, the seat strap just goes through the cushion.


On commercial jets, is asymmetric thrust used as part of normal operations?

This paper from Boeing sheds a light on the subject:

  [A]n intentional engine throttle up or down could create a desired yawing moment followed by a desired rolling moment. Using asymmetric thrust to control roll is not precise because of the lag time associated with engine spool-up or spool-down and should be avoided unless no other means of roll control are available.

While the paper is admittedly about righting the plane from an in flight upset, and is therefore based on a disaster scenario, the message still applies to everyday flight: asymetrical thrust is not the preferred method of control, as the delay between adjusting the throttle and the actual thrust change makes it less precise for maneuvering than the main control surfaces.


Why would a Cessna 182T not enter a stall?

I think this is more common than you might think in a C182. The 182 is much more nose-heavy than a 172 (which is particularly noticeable in the flare) and this seems to limit the amount of upward pitch authority the elevator has at low speeds. The only stalls I've done in a 182 are much as you described - you can hold full back-elevator and you just sort of sit there sinking.

Spinning could be an issue if it becomes uncoordinated, but a 182 is a very stable airplane and unlikely to enter a flat spin unless the CG is beyond the aft limit or severely uncoordinated. Perhaps someone else can weigh in further on that possibility, though.


Is engine damage due to a fan blade failure irreparable?

This depends on the failure: A fan blade can be damaged by birds, debris, or aircraft parts (pitot probe for example).  In this case the blades are dented, in which case it is possible to replace the damaged parts, inspect the engine and re-use it.

For this kind of damage it has to be disassembled and inspected by the engine manufacturer.

Inspection of blades is done with a microscope: For example, I have seen an HPT blade declared unserviceable because of a small scratch.

Obviously if the repair costs more than a new engine you don't repair the old one.

Many more things can happen in startup:

The engine is run on full power
There is a lot of possible interactions (like birds for example) that you don't have in a steady cruise at 40,000 feet.

Aside from debris, you can also have a compressor stall like this.


How do you correct a mistake on a pilot license?

I had this happen to me on my first license. I got in touch with the FAA Examiner and he had me contact the local Flight Standards Office (FSDO) who corrected it for me.

If it was a mistake on the application, your Certifying Officer (read: FAA Examainer) can allow you to edit the information through IACRA (https://iacra.faa.gov/iacra/default.aspx) and the license re-issued.

If all of the information was correct, but it was misprinted, you would want to call your local FSDO.

FSDO Search: http://www.faa.gov/about/office_org/field_offices/fsdo/

Your local FSDO can help you with:

Low-flying aircraft
Accident Reporting
Air carrier certification and operations
Aircraft maintenance
Aircraft operational issues
Aircraft permits
Airmen certification (licensing) for pilots, mechanics, repairmen, dispatchers, and parachute riggers
Certification and modification issues
Enforcement of Airmen & Aircraft Regulations


Why aren't requirements to use GNSS systems in the Regulations?

There are formal rules required to make new federal regulations and it would be incredibly difficult and time-consuming to put every detailed point through committees, public feedback etc. (Some people might actually see that as a good thing, but that's a discussion for another site.)

As for your specific example, 14 CFR 1.1 defines "suitable RNAV system" as (emphasis mine):

  an RNAV system that meets the required performance established for a type of operation, e.g. IFR; and is suitable for operation over the route to be flown in terms of any performance criteria (including accuracy) established by the air navigation service provider for certain routes (e.g. oceanic, ATS routes, and IAPs). An RNAV system's suitability is dependent upon the availability of ground and/or satellite navigation aids that are needed to meet any route performance criteria that may be prescribed in route specifications to navigate the aircraft along the route to be flown. Information on suitable RNAV systems is published in FAA guidance material.

In other words, "there's far too much detail here to make this a regulation, and technology keeps changing anyway. So just go read our dedicated documentation on it".


Do Landings in a Simulator Count Towards Landing Currency? (FAA in the USA)

Yes, as long as the simulator is properly certified (to level B,C,or D) you can do your takeoffs and landings to regain currency.

Long haul airline pilots frequently have trouble staying current for 3 takeoffs and landings in 90 days. This is because it takes 4 pilots to complete a long haul flight but only 1 will get the takeoff and landing.

3 trips a month is about all you do, and if you are scheduled to be the augment pilot, you don't get a takeoff and landing.


Is it possible to determine the approximate climb rate of an aircraft knowing its top speed, engine power and weight?

Yes, but the process will be indirect. For a rough estimate, the engine power- which is the rate at which it can perform work- can be thought of as lifting the mass of the aircraft upwards against gravity. Since the units of power are foot-pounds per second and velocity is in feet per second, the engine power and the aircraft's mass can be used to solve for the climb rate in feet per second (be sure to use the right units for mass). this ignores airframe drag and propeller efficiency losses and as such yields an absolute upper limit for the maximum possible rate of climb. Your mileage will be lower!

Note that engine power depends on density altitude, and hence this estimate holds only for the density altitude at which the engine's power rating was measured & specified.


Is it required for pilots to contact ATC while flying VFR?

It depends on which class of airspace you are flying in. For airspace classes A, B, C and D, a continuous two-way radio contact with ATC is required for all VFR flights. In airspace classes E, F and G, there is no such requirement.
The below table shows requirements for both IFR and VFR to fly in different airspace classes (source: ICAO Annex 11, Appendix 4). You should notice the second column from the right, which specified the radio communication requirements for a given airspace class.

These are general rules, that apply to all ICAO member states (basically, every country in the world), unless a specific state has decided to deviate from the ICAO standards. Such deviations will be listed in the national AIP, section GEN 1.7. For example, in some countries, two-way radio communication may be required for VFR traffic within certain airspaces classified G, even though that is generally not the case. A table with rules specific for your country will be available in your national AIP, section ENR 1.4, and will probably look quite similar to the above.
At controlled airports, a control zone will be established, which will be class A, B, C or D (cf. ICAO Annex 11 para 2.6, a control zone cannot be classified E). This means that, at a controlled airport, VFR traffic must establish a two-way radio contact with ATC, just like IFR.
At uncontrolled airports, however, this is generally not required.
During the approach, departure and en-route phases of flight, whether or not you are required to be in contact with ATC depends entirely on where you are flying. Very generally speaking, if flying close to controlled airports or above a certain level, you can expect the airspace to be controlled, and thus, contact with ATC is required. At low altitude, away from major airports, the airspace will often be uncontrolled, and no radio contact required.
The above is a very general description, and you really must refer to local charts and procedures to figure out if you are required to contact ATC in a specific area.
As a point of advice, ATC is there to help you. It is a good idea to contact ATC even if you are not required to do so, in order to receive flight information service and alerting service. This allows you to receive important information about traffic, weather, military activity, etc., and if something happens to you, a search and rescue mission can be initiated without delay.


Are there any contemporary advantages in favor of wing warping?

All wings warp. The extent of warping is one restriction which limits the fast side of the flight envelope.

Once aircraft designers realized that thick wings have less drag, they tried to build their wings as stiff as possible. Stiff wings allow to use airfoils with rear loading, will have higher flutter frequencies and keep their shape even when operating at high dynamic pressure.

Since the center of pressure moves chordwise on cambered airfoils depending on the angle of attack, any cambered wing will suffer from pitching moments around its axis of elasticity. This moment will twist the wing and change the incidence of the outer wing sections. A stiff wing will suffer less twisting and stay closer to its ideal aerodynamic shape. Add an aileron, and another twisting moment is added on top. Now the wing twists opposite to the aileron deflection! This can become so bad that most of the aileron's effectiveness is lost as the wing is warped in a way which counteracts the lift change of the aileron.

The X-53 research aircraft uses this effect with an array of leading and trailing edge devices to actively warp the wing in the desired direction. Using computer-controlled deflections of small but very effective control surfaces, it creates a desired deformation of the wing for roll control.

This can be compared to the effect a Flettner tab has on an aileron. The Flettner tab is a small control surface at the trailing edge of a larger control surface and is deflected by the pilot such that it moves the big control surface in opposite direction. It slightly reduces the effectiveness of the big control surface, but needs only a fraction of the stick force, thus helping to manually control big aircraft.

Since the active wing warping of the X-53 depends on the proper functioning of the FCS and an array of movable devices, each with its own failure mode, I would hesitate to see this as a clear advantage. It allows, however, to control the aircraft at high dynamic pressure with minimal drag penalties.


Having one door is just a design preference which makes the aircraft simpler, and lighter to build.

There are many other light aircraft with only one door. Besides Piper, most Mooney, Beechcraft, and Bellanca aircraft only have one door. Even the high wing Cessna 195, 206, P210, 337, and low wing Cessna 310 and 340 have only one door.


Depends what you define as a bonafide control? Lets look at the F/A-18C

Releasing a weapon from the aircraft is not just a case of pushing the red weapons release button or trigger. A MASTER ARM switch is included to prevent the accidental discharge of weapons, (and in some other aircraft countermeasures and stores jettison functionality). The MASTER ARM switch is not painted.

However this is still not enough, as the systems of the aircraft have to be programmed to release the selected weapon, perhaps by selecting the relevant weapon as configured in the STORES MFD page. In (most?) Hornet (blocks?), the MFD symbology is monochrome green regardless of the page selected.

There are shortcuts into weapons master modes though: The lowest hat switch on the stick is a shortcut into A/A master mode, with each direction selecting a different A/A weapon and the MFDs being changed to relevant pre-set pages. This switch is black, much like the other stick controls.

So, the pilot, colour-blind or not, has to be able to locate multiple controls in order to release anything from the aircraft, which are neither painted bright red, the same colour or any differentiating colour from their surroundings, except for the weapons release itself.

There are enhanced answers to be provided regarding workflows, muscle memory, the actual shape of the controls, training and the priorities of selection. There are much better qualified people here to talk about those.

P.S. I would provide an image to show where these controls are, but I'm not able to currently.


What happens if one or more rotors are stopped during autorotation on a quadrotor?

After watching the video the problem he was having was in keeping it horizontal. It appears that the software isn't able to control the unpowered motors.

I know absolutely nothing about quads but I'm assuming with a fixed rotor pitch they must use variable voltage to the motor to control everything such as translational movement. I'm also assuming they have an accelerometer to determine pitch. The first question is how accurate the accelerometer is at low g's.

Second, when in free fall if a rheostat that is controlled by the computer could be connected across the sides of the motor then your problem could be solved. The freewheeling motors will create a voltage just like a generator so a rheostat would be able to control the current and thus the mechanical resistance to the motor. The rheostat will have an inverse relationship with the mechanical resistance (more electrical resistance less mechanical resistance). How linear that relationship is you'll have to experiment with. If you have the software switch to controlling that resistance it should be able to direct the freefall in the same way it does everything under power, only it will be more limited In its authority. If you do it right you might even be able to use the power generated to recover a little bit of the energy from the fall to charge the batteries like a hybrid car does.

Like I said, I know absolutely zero about quadecopters so I can't fill in any details, but it seems feasible.


In a history of NASA's Icing Research Tunnel, "We Freeze to Please," NASA SP-2002-4226, Fig. 5-2 shows Hellfire missiles being tested.  But it conspicuously mentions nothing about de-icing systems for them, unlike the many pages that it devotes to de-icing for other aircraft and aircraft parts.  So it's likely that such de-icers are either still classified, or were deemed unnecessary.
Dohn Joe's remark, that Hellfires this icy could not be laser-guided, suggests that classified is more likely.


Can the fuel on the wing cause the aircraft to destabilize?

Yes it can. Source: I'm a pilot.

Most aircraft (even many small general aviation ones) have balance parameters where the fuel quantity in each side cannot/should not exceed that on the other side by greater than a certain amount.

Note that this is usually caused by fuel consumption in flight, not sloshing as you asked.

Also, (as in your question) fuel can slosh between tanks in most aircraft through the vent line that often connects one tank to another such as in light Cessnas. However this is usually only a small quantity and furthermore the aircraft is usually in level flight so it's not really a problem.

Fuel sloshing inside of one tank could potentially imbalance the plane a bit but I've never ran into any real effects of this nor heard anyone mention it. Furthermore, most aircraft have some sort I baffles in the tanks (usually wig ribs) that prevent much sloshing, whether by design or not.


What is the temperature of intake air at several speed of sound intervals from 1x to 10x?

Thermodynamics is your friend here. Compression in a ram intake is ideally isentropic (meaning entropy stays constant, so the whole process is reversible). In reality, some viscous losses cannot be avoided but are in the low percentage range in a well designed intake.

The temperature $T$ in isentropic compression from a state 1 to a state 2 can be calculated from the pressure $p$ and the ratio of specific heats $\kappa$:
$$T_2 = T_1\cdot\left(\frac{p_2}{p_1}\right)^{\frac{\kappa-1}{\kappa}}$$

$\kappa$ is 1.4 for air, so if the saber engine flies in air 250 K cold (-23.15°C) and a pressure of 500 mbar, and the intake compresses this air by a factor of 10 to 5,000 mbar, the temperature will ideally rise to 483 K (210°C). In reality, this might well be 220°C or 230°C due to viscous heating of the air in the process.

How the temperature ratio depends on flight Mach number $Ma$ (again, ideally) can be seen from this plot, based on this way to calculate the pressure rise:


How would I calculate CG in this practice problem?

Not too much theory, just simple math.  You find the spot where the sum of all torques
(mass x distance) = zero.  Where you would balance the plane on a see-saw. That is
your CG

If you start out with 2300 lbs at 95.75 inches and remove 170 lbs at 87.00 inches, the torque
of 170 x 8.75 = 1487.5 inch pounds has been removed.  The new weight is 2130 lbs.

The new CG is 1487.5 inch pounds/2130 pounds = 0.70 in the OTHER direction.
So new CG is at 96.45 inches.


How are pilots trained to prepare for crashes?

From my research to date it seems that most general aviation and commercial fixed wing pilots are instead trained rigorously in crash avoidance rather than crash escape. Flight attendants and other cabin staff drill regularly in crash preparation and cabin evacuation in several situations (gear-down landing, belly landing, water landing, fires blocking escape doors X, Y and Z, etc) but in an emergency, the job of the people behind the yokes is to first make sure the plane gets back on the ground in as close to one piece as possible; nobody's walking away from a nose-down dive into a mountain.


Are large jet turbofans so easy to spin?

Yes, large turbofans can be turned by hand without too much force. On smaller aircraft this is regularly done as part of the preflight walkaround. You can see an example in this YouTube video of an A320 walkaround:

Admittedly, the pilot turns the engine with four fingers here, but you can see that not much force is required. Turning it with a single finger would easily be possible.
On a larger aircraft like a Boeing 777 you cannot reach the fan when standing on the ground in front of the engine. Spinning the fan by hand is therefore not usually done during the preflight.
This video shows a GE engineer turning the fan blades of a GE90 (the predecessor of the GE9X) engine by hand:

Again, it is not one finger, but he is not using much force to turn it, so it should be possible with one finger.