What is the difference between a rating and a certificate?

@CrossRoads is sort of correct, but is off on the details. The comments cover some of it, and I’d like to clarify and add some detail.

For purposes of airmen certification aircraft are divided into Categories and within Categories there are classes.

14 CFR §61.5 Certificates and ratings issued under this part.

  (1) Aircraft category ratings—(i) Airplane.(ii) Rotorcraft.(iii)
  Glider.(iv) Lighter-than-air.(v) Powered-lift.(vi) Powered
  parachute.(vii) Weight-shift-control aircraft.

  (2) Airplane class ratings—(i) Single-engine land.(ii) Multiengine
  land.(iii) Single-engine sea.(iv) Multiengine sea.(3) Rotorcraft class
  ratings—(i) Helicopter.(ii) Gyroplane.

A typical student pilot will train in an Airplane with a single engine that is equipped with tires—not floats. When pass their checkride they get their certificate with a Private Pilot, Single-Engine Land rating.

Once they have their certificate, they may begin to fly different airplanes that need endorsements in their logbooks. CFR §61.31 covers these. You would need an endorsement in your logbook to act as PIC for an  airplane with over 200 horsepower; a complex airplane—controllable pitch, flaps, and retractable gear; or with a tailwheel.

A pilot may also get additional ratings to fly multi-engine aircraft, seaplanes, etc. Note that ratings require additional training and testing by a DPE while endorsements require training and logbook endorsements by a CFI.

A type rating is required by §61.31  for Large aircraft (I think this means over 12,500 lbs), turbine-powered aircraft, and other aircraft specified by the FAA.

Earlier I mentioned that when you pass your checkride you will have a Private Pilot rating. There are several other ratings that apply to your certificate, starting with your Student Pilot rating.

14 CFR §61.5   Certificates and ratings issued under this part.(a) The following certificates are issued under this part to an applicant who satisfactorily accomplishes the training and certification requirements for the certificate sought:
(1) Pilot certificates—
(i) Student pilot.
(ii) Sport pilot.
(iii) Recreational pilot.
(iv) Private pilot.
(v) Commercial pilot.
(vi) Airline transport pilot.
(2) Flight instructor certificates.
(3) Ground instructor certificates.

Sport pilot and Recreational pilot certificates have some limitations on the type of aircraft you can fly and require logbook endorsements for some privileges (e.g. flying in Class B for recreational pilot).

The instrument rating (§61.65   Instrument rating requirements.) is kind of odd in that it isn’t listed in the types of certificates, but it is an add-on to your pilot certificate. So a commercial pilot usually has an instrument rating and a CFI must have an instrument rating in order to qualify as a CFI.

Completely separate from all of this, aircraft themselves are classified as well.

Certification of Aircraft is covered by PART 23–AIRWORTHINESS STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES Among other things it sets out the four types of aircraft that are normally flown in Part 91 operations.

14 CFR §23.3 Airplane categories.
(a) The normal category is limited to airplanes that have a seating configuration, excluding pilot seats, of nine or less, a maximum certificated takeoff weight of 12,500 pounds or less, and intended for nonacrobatic operation. Nonacrobatic operation includes:

(1) Any maneuver incident to normal flying;
(2) Stalls (except whip stalls); and
(3) Lazy eights, chandelles, and steep turns, in which the angle of bank is not more than 60 degrees.
(b) The utility category is limited to airplanes that have a seating configuration, excluding pilot seats, of nine or less, a maximum certificated takeoff weight of 12,500 pounds or less, and intended for limited acrobatic operation. Airplanes certificated in the utility category may be used in any of the operations covered under paragraph (a) of this section and in limited acrobatic operations. Limited acrobatic operation includes:

(1) Spins (if approved for the particular type of airplane); and
(2) Lazy eights, chandelles, and steep turns, or similar maneuvers, in which the angle of bank is more than 60 degrees but not more than 90 degrees.
(c) The acrobatic category is limited to airplanes that have a seating configuration, excluding pilot seats, of nine or less, a maximum certificated takeoff weight of 12,500 pounds or less, and intended for use without restrictions, other than those shown to be necessary as a result of required flight tests.
(d) The commuter category is limited to propeller-driven, multiengine airplanes that have a seating configuration, excluding pilot seats, of 19 or less, and a maximum certificated takeoff weight of 19,000 pounds or less. The commuter category operation is limited to any maneuver incident to normal flying, stalls (except whip stalls), and steep turns, in which the angle of bank is not more than 60 degrees.
(e) Except for commuter category, airplanes may be type certificated in more than one category if the requirements of each requested category are met.


What is the difference between azimuth and heading?

A heading (in the general case of moving "forward") is the direction your nose is pointed in. This may not be your course (as discussed here).
Headings are measured from onboard a traveling vehicle or object (e.g. from the cockpit of an aircraft or the bridge of a ship at sea).

An azimuth is a bearing, more precisely a compass bearing from a specific point of observation like a radar station. (The "North" used as a reference may be either magnetic or true depending on the system you're working with, but for purposes of this discussion it doesn't matter.)
Often the point of observation is fixed (ground radar, a control tower, an artillery spotter, etc.), though it need not be as long as the observation can be mapped to a compass bearing somehow.

Bonus Answer: The "O'Clock" positions are an informal type of relative bearing as mins noted: The 360-degree circle is broken up into 12 chunks (30 degrees each) for easier scanning, with "12 O'Clock" being directly in front of you and "6 O'Clock" directly behind.

An important caveat to be aware of is that when ATC provides a "clock bearing" for traffic it's relative to the aircraft's course (12 O'Clock is aligned with the aircraft's track over the ground as shown on the radar). Depending on wind there may be considerable variation between your course (direction of travel) and your heading (direction the nose is pointing), so the called traffic may appear in a different location when you look out your window.


Was the P-82 twin Mustang better than the P-51D?

The two planes serve very different roles. The 82 was a long distance aircraft first and foremost, and everything else was secondary to that goal. The 51 was a fighter, and its excellent range was not a specific design criterion, but the result of several unrelated design decisions that worked in happy concert.
So, based on that alone, I think the answer is clear.
But the real issue with this comparison is the time dimension, the 82 saw combat when it was already outdated, whereas the 51 saw combat when it was the pinnacle of performance. Jets were already the hotness when the 82 was on the front line, and I doubt anyone looked favorably on being assigned to them when the alternative was an 84 or 86.


Would an ASTERIX decoder be "radar data processing" or "surveillance data processing"?

You would call this surveillance data processing, but typically surveillance data processing involves much more than decoding ASTERIX.

ASTERIX has many formats, not only radar but also multilateration, ADS-B, tracker output etc, hence the more generic term surveillance is used in lieu of radar.


Air to air Missile Guidance vs countermeasures

Basically, the missiles are engaged in a (deadly) game with the aircraft every time a missile is fired. All countermeasures are based on 'confusing' the missile homing systems to a certain extent, usually in the terminal stage. Missiles (or AD systems in general), use a number of methods to overcome this.

The general term for overcoming the countermeasures used by the aircraft is called counter-counter measure (CCM); in case of electronic warfare, electronic counter-counter measure (ECCM) is used.

In case of IR missiles, the aircraft should first know it is being targeted. The usual method is to use a Missile Approach Warning Sensor (MAWS), which detects the missile plume. However, this is not a foolproof method. As far as IR missiles are concerned, the target is usually unaware of the missile lock. The problem with laser guided short range missiles is also quite similar.
A number of newer missiles have dual/multi mode seekers (like IR/UV in Stinger), which helps it differentiate better between the target and decoy. Though decoys can mimic the target in one band (for e.g. IR), it cannot mimic in both the bands (flares have different UV signatures compared to the aircraft).
The missiles can be programmed to ignore the decoy (for e.g chaff) and lock only onto the target signature (rather than locking on to the strongest signal return).
The missiles can differentiate between the target and decoy using the differences in their trajectory.
The missile can discriminate between the target and decoy by using a higher resolution seeker.

It is quite difficult to have a system that couldn't be fooled. Though a video/TV guided missile would come quite close, it is quite impractical in real world. Some laser guided missiles are touted as 'unjammable', but this claim is questionable. Best option is to have a multi-mode seeker that locks onto the target in different regions of the electromagnetic spectrum, though this would make the missile too expensive (again, countermeasures are possible).


Is sustained inverted flight possible with any of today's commercial jet aircraft?

Theoretically, it is possible to fly an aircraft upside down. Good examples are the barrel roll done by Alvin "Tex" Johnson in Dash-80 (the predecessor of Boeing 707) and the actions of Pilot Flying James Tucker during the hijacking of Federal Express 705. However, the question is whether the maneuver can be sustained for and reasonable periods of time.

In this matter, the statement of Boeing (manufacturer of MD-80 after merger with McDonnell Douglas) is instructive:

  The MD-80 cannot sustain inverted flight,...The MD-80, as with all commercial airliners, was designed to fly upright. Commercial airliners are only tested and certified for upright flight.

The pilots of Alaska Airlines Flight 261, a MD-83, tried to fly their aircraft upside down for recovery, but were unsuccessful.


Why are 4 engine civilian turboprops not produced anymore

Well, military turbo-props are supposed to carry a large load at lower speeds, they wouldn't work well in passenger airplanes now because a jet plane can carry the same amount of passengers for a longer distance and faster than a turbo-prop can. However, they still use double-engined ones because they fly short, low-density routes to save money over using larger jet planes.


Why don't airliners use light strips on physical controls (yoke/stick, throttle and trim) to indicate who has control - pilot or flight computer?

They do.
On the 737 there is a light in the button for each autopilot and next to the autothrottle switch. As well as annunciation in green text at the top-center of the Primary Flight Display (PFD).
I'll see if I can find, or take, a photo (that isn't copyrighted) to illustrate this.
The indications are there; the challenge can be getting thru the information overload so that the pilots realize what the aircraft is telling them.


Can aileron differential eliminate adverse yaw?

That depends on flight speed.
Adverse yaw is strongest at low speed. A high-aspect ratio configuration will not be able to avoid adverse yaw, regardless of the degree of aileron differential.
At high speed the same airplane might roll fine without rudder corrections, because then aileron differential will be able to compensate for the then low adverse yaw if enough differential is provided.
Depending on airfoil rear camber, adverse yaw is also good for reducing aileron control forces. Again, the effect varies with speed and will result in a high degree of force reduction at low speed while forces are still high at high speed. The need to keep aileron forces growing with deflection angle is normally the limit for aileron differential, so it is impossible to tailor differential to overcome adverse yaw at low speed even for wings of moderate aspect ratio.


Are there any GA trainer aircraft without toe brakes?

There are still many Ercoupes in the fleet that don't even have rudder pedals, never mind toe-brakes on the rudder pedals.
You may also want to consider arranging for a more commonly-available trainer (e.g. Cessna 152, Piper Tomahawk, Diamond DA20, etc.) to be equipped with hand-controls for braking. This is done for individuals who have any number of reasons that they can't operate the rudder pedals with their feet, such as paraplegia, deformity, etc.
See e.g. https://www.freedomintheair.org/hand-controls/, https://www.newmobility.com/2019/01/pilots-planes-hand-controls/, https://www.wired.com/2009/08/hand-control-airplanes/, https://abilitymagazine.com/hand-controls-for-flying/, etc.


Why don't we see business jets with wingtip fuel tanks anymore?

One of the main reasons wing tip tanks were used was to counteract some of the forces of wing bending by adding mass to the end of the wings. As time has progressed and our understanding of materials has grown as well as our ability to design structures better the need for tricks like this has gone away.

As our general understanding of aerodynamics has gotten better so has the understanding of the impact of wing tip shape on reducing drag. As such wing tip tanks have been traded out for wing tip devices.

In some cases the tip tanks are an option available as a later add-on or at purchase time. Generally this increases the range of the aircraft at the cost of useful load. As such, it may just be that most people who order planes these days prefer the higher useful load and the reduced range, rather than the extended range flying with a lighter load.

You can find some more discussion on it here.


Why do I have to turn off my (non-cellular) iPad before takeoff?

Actually, they don't!  Well, not always anyway.

The FAA recently issued a press release titled FAA to Allow Airlines to Expand Use of Personal Electronics.  This press release allows for the use of some electronics, including iPads and similar devices, during all phases of flight,.  However, it is up to each airline to change their procedures and to determine which devices can be safely used.

This is a small excerpt from the press release:

  Passengers will eventually be able to read e-books, play games, and
  watch videos on their devices during all phases of flight, with very
  limited exceptions. Electronic items, books and magazines, must be
  held or put in the seat back pocket during the actual takeoff and
  landing roll. Cell phones should be in airplane mode or with cellular
  service disabled – i.e., no signal bars displayed—and cannot be used
  for voice communications based on FCC regulations that prohibit any
  airborne calls using cell phones.    If your air carrier provides
  Wi-Fi service during flight, you may use those services.  You can also
  continue to use short-range Bluetooth accessories, like wireless
  keyboards.

I flew on Jet Blue the day after that press release and they were already allowing iPads and similar devices as long as they were in airplane mode.  Other airlines will follow soon I'm sure, but their manuals and procedures must be updated and approved by the FAA first.


Is there any work on improving fuel tanks so they could store hydrogen?

First, to debunk a myth regarding the Hindenberg, which always gets brought up whenever hydrogen is mentioned. Hydrogen is less safe than liquid fuel, but it is not less safe than natural gas or propane. Hydrogen has a higher flame propagation velocity than hydrocarbon gasses, but contains much less energy per unit volume than hydrocarbon gasses. A huge airship filled with natural gas would be just as hazardous as a huge airship filled with hydrogen, yet we have natural gas pipework running to our houses and with proper controls there are very few incidents.

Nevertheless, hydrogen is not a good fuel for aircraft for the following reasons.

(Source: Wikipedia)

Above shows that hydrogen contains about 142MJ/kg of energy compared with about 42MJ/kg for kerosene. However it contains a lot less energy per unit volume. Liquid hydrogen contains only 10 MJ/litre while kerosene contains 33MJ/litre. Therefore hydrogen fuel tanks would need to be more than 3 times the size of kerosene fuel tanks. Gaseous hydrogen at atmospheric pressure would occupy hundreds of times more space, while hydrogen at 700bar is only about a factor of 2 worse than liquid hydrogen, but the weight of a vessel for holding 700bar pressure would negate the weight advantage of hydrogen.

Therefore the most practical way of storing hydrogen in an aircraft would be in the liquid state, as is used in spacecraft such as the Space Shuttle. Use of hydrogen would result in some weight savings and hence fuel savings. However the fuel tanks would be so big that the savings would be partially negated by the the additional drag (not to mention the additional weight of the larger tanks.)

Hydrogen is expensive to produce and liquefy. Most hydrogen is produced by reforming natural gas and steam into hydrogen by the reaction CH4 + 2H2O = CO2 + 4H2, which is a highly energy intensive process. Therefore, although a hydrogen fuelled plane might consume less energy than a kerosene fuelled plane, this does not take into account the energy used in the process of producing and liquefying the hydrogen, nor the cost involved in doing so. Overall, hydrogen fuel is likely to be more expensive.

Hydrogen is also more difficult to handle. hydrogen tanks are never perfectly insulated, so hydrogen boils off, and the tanks ice up. It is also, more hazardous than liquid fuel if a spill occurs, as it will evaporate and create an explosive mixture in air (though, as I have said above, this issue also applies to natural gas.) Liquid hydrogen is much colder than liquefied natural gas, and so creates more problems with materials, boiloff and icing.

Industrial gas turbines can run on hydrogen without too much modification. But with the extensive certification procedures for aviation, modifying an aircraft engine for hydrogen will be quite costly. Also the faster flame velocity of hydrogen means that NOx is more difficult to control and this is likely to cause problems with emissions regulations.

In conclusion, the only way hydrogen is ever going to be viable in the aviation industry in general is if it turns out to be easier to use in a fuel cell driven craft than a hydrocarbon fuel.

If economically feasible, a fuel cell / electric motor drive would be more efficient than a combustion jet engine. That said, the practical and safety issues mean that the aircraft industry will be one of the latest adopters of such technology.


What is the folded size of a sectional map?

One seller's link on Amazon claimed 10" x 5", but when I measured an old one (only one I have handy), it was between 10.25" and 10.5" long by 5" wide. So I'd recommend using the latter value, knowing that the chart will probably be a hair under 10.5" long and so you have room for error (or a badly refolded chart).


Yes.  Black boxes aren't designed to be tamper-resistant.

The hard part is not the physical act of tampering with a black box, it's constructing a coherent false narrative of what happened during the time period.  The FDR records 80+ channels of data, which an investigator can correlate against each other, against data in the quick access recorder, against ACARS reports, and against the physical condition of the airplane itself.

For example, say you want to "prove" that an airplane's engines were shut down mid-flight, leading to a crash.  You could modify the FDR's record to show a throttle setting of "closed" and an engine RPM of 0, but the exhaust temperature would still be high, the fuel tank levels would still be dropping, and analysis of damage to the turbine blades would show a mix of axial and circumferential bending around the entire circumference of the blade disk, rather than the pure axial bending on a single side that would be expected if the engines had stopped spinning.


This has a pretty broad range of answers for this, but I assume what you are asking is what a flight ready QF-16 would sell for should it become instantly available on the civilian market.

Well the short answer is whatever someone is willing to pay for it.

The long answer is that aircraft values are based on a large range of variable, including, but not limited to, the value of the airframe, the current time and status of all life limited parts, currency of all required inspections, status of airworthiness directive compliance, avionics, outstanding repairs and overhauls, etc.

Now assuming this QF-16 is an acquired F-16A reclaimed from AMARC, with a reasonable amount of time left on the airframe, engine and all functioning avionics and systems as manufactured in the early 1980s by GD Fort Worth, the jet could easily command 15 million in FY2019 USD.  Now the QF-16 conversion costs vary depending on the contract signed but typically go for about 1.1 million per jet.  Add to that a dealer and/or brokerage fees of 15% sale price, the cost of flight training a reasonable budget might be 50 or so hours at $25,000 per flight hour or 1.25 million, this gives you an out the door price in the neighborhood of 19.6 million - that is if Congress will sell it to you.


Is it okay to ask the Call Sign of the plane to Pilots / Flight crew during boarding?

Mostly you wouldn't need to ask. Most commercial flights use the airline's standard call sign and the flight number printed on your ticket. Sometimes the call sign can be confusing - British Airways use 'Speedbird'; PAN AM used to use 'Clipper'. There's a list of common callsigns on http://www.pilotcareercenter.com/Search-Air-Carrier-By-Name-Region-Aircraft-Type-Radio-Callsign#callsign

The flight number should be enough - just listening for calls referring to 'two-two-zero' will almost certainly identify United 220. Code-sharing flights, however, will generally use the flight number of the operating airline. Your ticket might say 'United 220', but if the flight is operated by, say,  American Airlines so the call sign might be 'American 406'.

All that said, if you're using your phone when you have been explicitly asked to turn it off the airline is within its rights to confiscate your phone or remove you from the flight.


Why weren't SA-On GPS units updated to become SA-Aware?

As the linked ICAO article on GPS accuracy states, the issue is not just the navigation accuracy but the reported accuracy which is critical when used for ADS-B.
From the report:

3.2.1 For GPS receivers which are not SA aware, the accuracy and integrity REPORTED and then used in ADS-B messages is based on an
ASSUMED value of UERE, corresponding to the period when SA was active.
This value is grossly larger than the accuracy of the positional data
delivered now that SA is inactive.
3.2.2 For SA off/ SA aware receivers, some report accuracy and integrity values based on the assumed UERE in the SA inactive
environment and some determine the UERE from the GPS message contents.
Thus SA aware systems report more realistic accuracy and integrity
values.

When SA was on it was implemented by dithering the satellite's clock and ephemeris data to create a UERE of approximately 32 meters. So there was no attempt in the SA On receivers to compute the UERE as it was basically fixed by the implementation of SA. Remember this was first implemented circa 1990 and ADS-B efforts were in draft form when SA was terminated.
Also GPS standards weren't revised just because SA went away. The changes were primarily driven by SBAS and GBAS development efforts not the need for ADS-B. SBAS was the basis for the TSO-C145/C146. The air transport market wasn't very interested in SBAS, they tended to lean towards GBAS (if they cared at all.) The TSO-C196 (SA Aware) is very much like the C145/C146 units but without SBAS. (I'm not really sure of all the history of this TSO as it was after my time working these products.)
Product changes around TSO changes are a fact of life. Trying to upgrade a product from one standard to a new one just doesn't happen as it is by definition a major change and requires a new certification. And even with a new GPS built to a new TSO, it can't be swapped into the aircraft without an STC and that's a major expense.
So, could the original TSO-C129 units be upgraded to be SA Aware (without going to the new TSO?) Theoretically they could, but not economically. Computing the real-time UERE has to be done within the GPS chipset which would require a complete redesign of the custom ASIC at which point it just worth moving to the new standard.
As for the preflight authorization requirement for the SA Aware (C196) units; it's because they don't have the SBAS integrity channel. They rely entirely on an aircraft based integrity process. This can cause periodic cases where the integrity is reported as unacceptable.

Glossary:

ICAO: International Civil Aviation Organization
GPS: Global Positioning System
ADS-B: Automatic Dependent Surveillance - Broadcast
SA: Selective Availability
UERE: User equivalent range error
SBAS: Satellite Based Augmentation System
GBAS: Ground Based Augmentation System
TSO: Technical Standard Order
ASIC: Application-Specific Integrated Circuit


Does a previous AFSP approval get invalidated when making a new training request?

Yes, you can have multiple requests open at the same time. This is from the AFSP Candidate Application Guide (step 7):

  It is possible for a Candidate to have several active training requests at a given time. These requests may be for the same or different flight training providers. Each training request form will be processed separately; AFSP approval is valid only for the Provider listed in the application.


Are there any electric ultralight aircraft?

ElectraFlyer offers a Part 103 legal trike, and at least as of two years ago, had a flying prototype of a more conventional designed single-seat Part 103 legal ultralight.

Realistically, given the weights of engines and batteries compared to the weights of the Rotax or similar engines usually used on ultralights, it's possible to turn many Part 103 designs into electric power, provided you're willing to do the engineering work yourself. For a fairly extreme example, see Dale Kramer's eLazair, a twin electric motor conversion of the Lazair ultralight that retains its Part 103 status.


How long to clear the 'suck zone' of a turbofan after start is initiated?

A start on a TF all the way to idle is about 20-40 seconds depending on the engine, and the fan itself won't do more than creep a bit until the core actually lights off which is 5-10 seconds, so they'll have lots of time to get down and get away as per @ymb1's diagram, once the wheeEEEEEEEEEEtickticktickticktickticktick starts.


Are life jackets mandatory on planes that will never fly over water bodies?

Assuming you are asking about civilian flights operated under FAA rules, part 91 rules (14 CFR §91.205(b)(12)) advise that approved and serviceable flotation devices are required to be carried for each occupant during flight where such flight takes place over water outside power-off gliding distance to shore. "Shore" has a specific definition.

If the aircraft is operated [for VFR flight during the day] for hire over water and beyond power-off gliding distance from shore, [it must carry] approved [and serviceable] flotation gear readily available to each occupant and, unless the aircraft is operating under part 121 of this subchapter, at least one pyrotechnic signaling device. As used in this section, “shore” means that area of the land adjacent to the water which is above the high water mark and excludes land areas which are intermittently under water.

These provisions are extended to VFR flight at night and IFR flight in 14 CFR §91.205(c) et seq.
Part 91 subpart F stipulates the requirements for large/turbine-powered multiengine operations (where such rules exclude flights for the purposes of common carriage). In summary, §91.509 requires approved flotation devices when operated more than 50 miles from the nearest shore, and liferafts, survival kits, etc for flights operated more than 30 minutes flying time or more than 100 nautical miles from the nearest shore.
Most "commercial" flights in large aircraft are further regulated in terms of equipment by sections under part 121, part 125, part 135, etc. with similar equipment requirements to those noted above (links take you directly to relevant sections of the code for extended overwater operations under each part).
If operating a commercial air tour compliant with part 136, and such tour is to take place over water beyond minimum gliding distance in a non-compliant aircraft except for the purposes of takeoff and landing, then the code in 14 CFR §136.9 is more strict: occupants must wear life jackets until at least the period when the flight ceases to be over water.

(a) Except as provided in paragraphs (b) or (c) of this section, the operator and pilot in command of commercial air tours over water beyond the shoreline must ensure that each occupant is wearing a life preserver from before takeoff until flight is no longer over water.
(b) The operator and pilot in command of a commercial air tour over water beyond the shoreline must ensure that a life preserver is readily available for its intended use and easily accessible to each occupant if:
(1) The aircraft is equipped with floats; or
(2) The airplane is within power-off gliding distance to the shoreline for the duration of the time that the flight is over water.
(3) The aircraft is a multi engine that can be operated with the critical engine inoperative at a weight that will allow it to climb, at least 50 feet a minute, at an altitude of 1,000 feet above the surface, as provided in the Airplane Flight Manual or the Rotorcraft Flight Manual, as appropriate.
(c) No life preserver is required if the overwater operation is necessary only for takeoff or landing.

In summary, for FAA aircraft operating solely over land, the regulations noted above and by Ralph J's comment proscribe that the required equipment to be carried is minimal.
Of course, what the letter of the law says, and what's a good idea to carry, may in some cases be different things -- I'm thinking here about good practice to carry additional life preserving equipment when operating a GA aircraft for an extended time over water.


What steps have been taken to rule out instrument failure due to blocked static ports or pitot tubes?

The best thing way to mitigate an issue like this is to draw attention to during the preflight check. Its becoming common to use covers that have a nice big red "Remove Before Flight" tag on them. These should be used as much as is practically possible (storage, cleaning, maintenance etc.)

Something like this would do nicely.

(source)

Similarly the aircrafts paint may be done in such a way to make the port stand out.

(source)

Caps/Covers for both static ports and Pitot Tubes are generally a good idea and can help prevent a clog that occurs while the plane is on the ground. As with anything diligence during preflight is key to avoiding this issue.

Most larger aircraft pilots call out "airspeed alive" during their takeoff roll as a way of confirming the Pitot system is working. If the air speed indicator does not read, the general procedure is to abort the takeoff.

Some aircraft may also be equipped with a radar altimeter which can help mitigate serious issues by providing an altitude system not based on the static system. However this only works at lower altitudes.


What is the difference between staged and unstaged fuel manifolds?

Staged means that fuel is delivered "after launch" instead of immediately.  This terminology is more familiar from staged rockets:

  At engine idle conditions, the electronic engine control (EEC) unit sends a signal to the BSV which then shuts off fuel flow to the ten staged fuel nozzles. As a result, the ten unstaged nozzles receive a higher fuel volume resulting in a stronger flame. [More fuel for those ten and none for the others, encouraging combustion: fewer flames, but bigger ones.]  As the engine accelerates above idle, the EEC signal commands the BSV open, allowing fuel to flow to all nozzles [more than the first ten] so the engine can operate at higher power settings.

This is quite like a campfire started with tinder (unstaged, ignites instantly) and then sustained with thicker wood (staged).

"Pilot fuel flow" is hard to google in an aeronautics context for obvious reasons, but it means the same as "pilot flame" for a household furnace or water heater.  It acts like a continuous low fuel consumption spark,
at start-up and low part load, to encourage more vigorous combustion shortly before that is commanded.


How many AOA sensors does the 737 MAX have?

The Boeing 737 MAX has 2 AoA sensors.

However, MCAS only takes input from 1 AoA sensor at a time.

Sources:

The black box flight recorder data for Lion Air JT610 shows the data from 2 AoA sensors, labeled "Left" and "Right".

Also, if you look at the nose of the 737 MAX, you will see a left and right AoA vane. (The sensors with the red tags are pitot tubes).

"[Boeing] said it will change the MCAS software to give the system input from more than one AOA sensor."


How frequent is the use of spoilers during descent?

Very frequent.

Modern airliners are certainly fairly slippery, but it's not so much that they're super-gliders that we can't wrestle down onto the ground.

It's more a function of busy airspace than a property of the aircraft. When you remove power from any aircraft, it's going to descend - the only question is the rate. I promise you that if you found yourself a long way from an airport in a powerless B737, you'd find that descent rate to be faster than you'd like!

The main reason for spoiler use isn't that a modern aircraft glides "too well" - but rather than the airspace is busier so aircraft are expected to respond a little quicker than in the past, which can make it more convenient to descend faster as a pilot. It also means that ATC will often ask pilots to maintain a higher-than-ideal airspeed on the descent: if travelling at 160 knots, you'll descend faster than you would at 180 or 200 knots, for example... but more often these days, you're asked to maintain a higher minimum airspeed for longer. That's often convenient for ATC as it gets you where you're going faster, and it's convenient for you too, because you get to go home faster: but it means you're travelling a lot further in the next minute, making it harder to hit the descent rates required, necessitating the use of spoilers in some circumstances.

Clarification: In this answer I've focused on the later stages of the flight: "Slower = descend faster" is not necessarily a universal constant - aircraft glide best at their "best glide speed" which is a function of drag, weight, and airspeed. This answer assumes that, as for most airliners, best glide speed is in the region of 200-250 knots, and that an airliner is unlikely to descend at/faster than their best glide speed in the approach phases where speeds are typically in the 150-200 knot range.

At lower altitudes when descending under ATC, the above ATC-centric discussion applies. At higher altitudes, it tends to revolve around efficiency and company policy: the longer you can stay at cruising speed/altitude, the more efficient your flight will be: therefore it saves the airline money to descend as late as possible, requiring a higher descent rate. Spoilers, of course, help with that.

TL;DR: Some of it stems from the aircraft design being more aerodynamic and therefore better at gliding, but it's more closely related to ATC being busier and therefore keeping aircraft higher/faster for longer, which requires higher descent rates and therefore the use of spoilers, along with the fact it's more efficient to stay high/fast in the cruise for as long as possible then descend later/faster


Does an uncovered naval aircraft suffer any weathering affects?

Naval aircraft cannot be just left on deck without maintenance and expected to operate after an extended period of time. I will restrict this to storage on deck and avoid going into operational issues like spray effects on engines as OPs question does not ask that.

There are a multitude of technologies in use to protect metal parts from corrosion, but in the end these all fight a losing battle against entropy and their effectiveness is more accurately measured in how long they can stave off corrosion.

Painted parts are probably the most resistant, as organic coatings provide a hard barrier over the vulnerable surfaces. Paint is not foolproof, however, as it can chip and crack, due to thermal stresses, FOD, etc. Furthermore, not all parts can be painted and corrosion can develop underneath paint if it has an entry point, like a rivet hole , a static discharge connector or a crack in the paint.

Where organic coatings are not suitable, for example on shock absorber struts, other coatings can be applied. For steel a common solution is a chrome layer; for aluminium, chromate conversion and anodizing. These solutions are not as effective as a coat of paint, and an aggressive-enough environment will attack even chrome layers. As an example, take landing gear struts, which have multiple exposed moving parts, many crevices to accumulate moisture and diverse metals ready to form galvanic cells.

Finally, there are places where no coating can be used at all: static dischargers. These do exactly what the name implies, ground the aircraft to allow for built up static charges to flow into the ground, so they need to be exposed and to contact (almost)bare metal on the airframe to ensure conductivity. Their connection points are typically covered in sealant after installation, but these sealants do not last forever: they weather and end up cracking after some years in the field, turning into a moisture trap and destroying the part they are on if not monitored.

Finally, a note on composite airframes.
CFRP parts are conductive and very noble, so they can easily corrode whatever metal is attached to them. This can be mitigated with careful engineering, but can come as an unexpected problem for systems suppliers that are used to installing equipment on metal airframes: an aluminium airframe will corrode before a steel tray attached to it without insulation, but the opposite will happen with a composite airframe.


The wing folding mechanisms (in aircraft) and rotor folding mechanisms (in helicopters) are different. The V-22 Osprey falls somewhere in the middle.

In case of aircraft, the wing folding mechanism is usually made of high grade steel (or titanium in some cases) and actuated either hydraulically (or in recent cases) electrically. The outer wing rotates about a hinge, to which the two parts (inboard and outboard) of the wings are locked. For example, the F/A 18 wing folding mechanism looks something like this:

Image from US Patent Wing fold push-pin locking assembly US 5558299 A

In general, once the wings are either folded (or unfolded), they are locked using very hefty sliding pins which provide a secure mechanical connection once (they) slid into place in sockets in the outer wing.

However, incidents do happen, usually because the pins have not locked and not because of failure. A number of incidents have happened where aircraft have taken off with wings folded (and landed safely, surprisingly).

Source : reddit.com/theaviationist.com

In case of helicopters, the blade folding method is more or less the same with some variations- pull the pin that holds the blade (on one side) and fold the blades, which is done manually for small helicopters and hydraulically for large ones.

Source: reddit.com

They are then held either by hydraulic pressure or mechanical attachments.

Source: adf-messageboard.com.au

At-least in helicopters, there is little chance of a takeoff with the wings folded.

The V-22 Osprey is a special case- The propellers (or rotors) is folded first, then the engines are rotated, followed by the wings themselves.


Correct.  True airspeed refers to the actual speed which the aircraft is moving through the air.  Ground speed is the speed at which the aircraft moves over the ground.  The formula

$v_\text{ground} = v_\text{true} - v_\text{wind} \cdot \cos(\alpha)$

Where

$v_\text{true}$ is the true airspeed
$v_\text{ground}$ is the groundspeed
$v_\text{wind}$ is the magnitude of the winds aloft
$\alpha$ is the angle of the winds aloft relative to the longitudinal axis of the aircraft.


What is the ceiling to prohibited space P-47 (or any other P-zone)?

Special Use Airspace is defined by boundaries in all three dimensions1. The horizontal boundaries are depicted on the chart as you describe. The vertical boundaries are in the sidebar of the chart:

You can see here that P-47 exists from the surface (because there's nothing before the "TO") up to 4800 MSL. KAMA is at at 3607 MSL, so P-47 ends 1200' above the airport surface. At a little more than 5 NM away from the airport (measuring on the sectional), that's about 240 ft/NM climb: well within the performance capabilities of almost every powered aircraft. Overflights on the victor airway obviously have no problem at all.

This is used for allowing traffic where it might otherwise not be possible: Consider P-40 and R-4009, above Camp David in Maryland. When the President is not in residence, R-4009 lies exactly on top of P-40. P-40, from the surface to 5,000, is a no-fly zone. R-4009, from 5,000 to 12,500, can be transited with ATC permission.

(1)There's always an exception: see R-2933, over Cape Canaveral: 5,000 to UNLIMITED.


How much effect does the ground have on flight control when flying low?

At the high speed of the F-15s in the video ground effect is almost negligible. Ground effect is about the restriction of downwash by the ground, and at high speed and air density downwash is rather small. Also, the duration of close proximity to the ground is too short for ground effect to fully develop.

The biggest effect will be air turbulence. Since air will neither flow into the ground nor out of it, the vertical speed of atmospheric turbulence is greatly reduced when flying close to the ground. Also, the scale of turbulence will get smaller with proximity to the ground. While gusts may rock your wings when flying high, at very low altitude (less than one wingspan) the turbulence will average out over the wing.

When flying over a ridge, any wind speed component perpendicular to the ridge line will mean updrafts on the windward side of the ridge and downdrafts on the leeward side. This will be the strongest effect in this particular case of F-15s flying over a ridge at Mach 0.7 to 0.9.

Now back to that ground effect meme which seems to find wide agreement here: Ground effect is a stationary process which is strongest at low speed, when the downwash behind the wing is strong. In the case shown here, the aircraft is only momentarily in close proximity to the ground. The pressure field around the aircraft will never reflect that proximity because it is gone before the aerodynamics could start to react. This is completely instationary aerodynamics, and air, having mass, will take some time to respond. However, it is never given this time.


Are there any methods to predict the location of a jet aircraft from its sound?

From a single spotting location, then yes by training. But for any location, then it's very hard. Our ears get confused when the sound reflects off the surrounding surfaces, e.g., ground, buildings, etc. And when the sound comes from above.

Most mammals are adept at resolving the location of a sound source using interaural time differences and interaural level differences. However, no such time or level differences exist for sounds originating along the circumference of circular conical slices, where the cone's axis lies along the line between the two ears.
Consequently, sound waves originating at any point along a given circumference slant height will have ambiguous perceptual coordinates. That is to say, the listener will be incapable of determining whether the sound originated from the back, front, top, bottom or anywhere else along the circumference at the base of a cone at any given distance from the ear.

Tilting your head might help though.
So much so, airplane spotters in WWII judging only by sound misjudged the direction of Allied bombers and the entire Luftwaffe was sent looking in the wrong direction, only to realize the direction reported was incorrect and they had to land once they started running out of fuel.

Göring freely admitted the laugh was on him, that he had sent the Luftwaffe on a mammoth tour of their own air space.

But with computers it can be done using 3D sound localization. Or good old locators:
(theatlantic.com) Chinese soldiers man a sound detector which directs the firing of 3-inch anti-aircraft guns, around the city of Chongqing, China, on May 2, 1941.
P.S. Same problem arises when trying to figure out where an artillery fire is coming from or going to.


The ground crew has connected a headset to the communication jack outsiede for flight pushback communication with the flight crew. from b737.org.uk:

The External Power Hatch is located beneath the F/O's DV window. It is used by groundcrew to connect the Ground Power Unit and headset for pushback communications with Flight Interphone.
The service interphone is used by engineers to communicate with the service interphone stations inside the aircraft.

Here is a closeup of the connection point

Image from b737.org.uk
About flight interphone System

The flight interphone system is an independent communication network. Its
primary purpose is to provide private communication between flight deck
crewmembers without intrusion from the service interphone system. The ground
crew may also use the flight interphone through a jack at the external power
receptacle.

And here is a nose section of 737-200, showing it from a not so close angle.

Image from rigger.smugmug.com


What materials are used to make up a combustion chamber?

If you are asking about combustor liners specifically (as opposed to the hot section in general), the ones I am familiar with are cobalt-based superalloys.


How does a commercial flight pilot handle turbulence?

Most of the time the turbulence we experience is termed "chop", which is akin to what you experience on a boat on the lake -- bumps but no real altitude deviations.  With altitude deviations we'll call it "turbulence".  Within these broad categories we'll qualify them with "light", "moderate", "severe" and "extreme" in reports to ATC and other aircraft.  These reports do suffer from a fair bit of subjectivity with respect to aircraft type (wing stiffness) and pilot experience.

If it is light chop, I'll generally just ride it out and turn the seatbelt signs on.

The first thing I'll do if encountering moderate chop or turbulence is to query ATC and get ride reports from aircraft ahead of us and at different altitudes than us.  From this information I'll make a determination to ride it out or to request a climb/descent.  If the turbulence was particularly bad, slowing down was an option, but I only came across that need a few times.  Our ability to descend would often be limited by route length and fuel and major lateral deviations also depended on contingency fuel, so in some cases we had no choice but to stay in the chop.  If the turbulent areas were well forecast or had lots of PIREPS, our dispatchers would sometimes route us differently.

As for power adjustments, if we weren't slowing down due to aircraft limitations I would just adjust power so that maximum airspeed deviations stayed below Mmo.


What is this little door on the upper deck of the A380?

It's for the emergency slide.

You can see it deployed here:

Source:  Airliners.Net


Can any land-based plane be made to land on water?

Well "any" is an awfully broad statement, but the answer is "Theoretically yes." -- You would just need floats that displace enough water to provide buoyancy for the aircraft at its maximum gross weight.

For a 747 that would be impractical: We're talking about a plane with a maximum takeoff weight in the neighborhood of 700,000-900,000 pounds depending on model and variant, and that would be an ENORMOUS set of pontoons. The form drag alone would be prohibitive, nevermind the structural work required to attach the pontoons in such a way that they won't be ripped off at takeoff speed in the water or blow off the plane in cruise flight.

For smaller aircraft it's certainly do-able: You can take a Piper Cherokee 180, remove the landing gear, and install floats (Piper kit #756-746) to make it into a seaplane:

Note the structural bracing for the floats, which attach both at the main landing gear point and the nose landing gear point to enable them to take the loads imposed by taxiing through water. There are also a bunch of additional seals and blanking plates installed as part of the seaplane kit to prevent the aircraft from taking on water.

Note however that just because something is possible doesn't mean it's a good idea, and the PA-28S is an example of that: The low-wing design of the Cherokee coupled with its single door on the right side makes the seaplane version an exercise in impracticality.


Does the crew have a professionally mandated responsibility to inform passengers of a potentially fatal emergency?

Would the act of informing passengers they may die be considered "professional" or "a responsibility of the crew"? No.

And if I may argue, it's the opposite: it is unprofessional for trained flight crew (either pilot or cabin crew) to behave this way.

The shortfalls of this action is obvious. Panic would instantly spread among the cabin. Many people would start behaving irrationally when they believe that death is imminent (hey, not everybody is strong psychologically). This could potentially turn a survivable situation into a deadly one.

In dangerous scenarios, anyone assisting needs to give assertive instructions. We don't tell people why they are doing it. We give very simple, but firm instructions such as "push!", "jump!". Fire fighters and other rescue workers also do it this way.

Telling people "uhhhh, I don't think we can make it" works against the goal of ensuring everyone has a best chance of survival, which is a professional responsibility of any crew member on a passenger flight.

Legally, there are no regulations, industry practices, or airline SOP that I'm aware of, that mandates informing passengers about the potentially fatal outcome of their flight.

Realistically, there aren't that many scenarios where this is possible. If it's a small problem such as high oil temperature or failed hydraulic pump, you won't even notice. If it's a stall or loss of control you'd be screaming already. If it's a inflight breakup you'd loss consciousness in less than 30 seconds. If it's a cabin fire you'd see cabin crew fighting it with fire extinguishers.

That leaves scenarios where the aircraft is stable in the air, but may break up upon landing. Examples would include landing gear malfunctions, flap malfunctions (causing very high landing speed) and total engine failure from high altitude. Historically, most of these incidents end up well. Spending the time to educate passengers emergency procedures (such as counting the number of rows to various exits; briefing how to open the emergency door) is more constructive then saying "On behalf of XXX Airlines, it is with sincere regret to inform you that our aircraft suffered a catastrophic failure and this may be the last moments of your life".

That said, I offer the following:

If you've been told to adopt the brace position, you may consider that it is in the opinion of the flight crew that severe injury and/or death is likely.


Why Apollo 11 was launched in summer? (Performance question)

The temperature of the environment doesn't have a significant impact on the performance of a rocket engine. Air breathing engines have better performance in cold air because the mass density is higher at a given pressure, which allows them to ingest more air, and because the thermodynamic efficiency of a heat engine increases when the temperature of the cold side decreases.

A rocket uses oxidizer from a tank, and the thermodynamic cold side temperature is the temperature of the propellant before it gets burned. Thus, atmospheric temperature doesn't change rocket performance like it does for air breathing engines.

Remember that rockets aren't pushing against the air, they're pushing against their own exhaust. Atmospheric pressure slows down the escape of the exhaust, reducing thrust. Rockets will produce more thrust in a vacuum than they will in the atmosphere.

The main concern for timing the launch of Apollo 11 was making it happen as soon as possible, both to beat President Kennedy's promise to land a person on the moon before the end of the decade, and to beat the USSR to the moon.


How does 220 kN of engine thrust create the 700 kN required to maintain the altitude of an A320?

The engines only need to overcome the induced drag to remain in the air, which is a result of the lift but usually much smaller on the order of 1/20 for a modern jet. This ratio is specified as lift to drag or L/D. It is a vital performance statistic of an aircraft. Why? Wings are weird and complicated, there is not a simple 100% correct answer.

Only a rocket needs thrust equaling gravitational force since it has no wings! (L/D = 1/1)


How to keep an aircraft stationary with an inoperative parking brake?

Keep pushing hard on the wheel brakes... And hope those do work, obviously.

If there's soggy ground next to the runway, let the aircraft roll onto that and the wheels should bog down into the mud.

There's precious little else you can do unless you want to deliberate drive the aircraft into something solid.


No passengers have crashed an airplane while the pilot was letting them fly.

In this situation, the PIC crashed the plane because he didn't do his job as the captain and final authority for the safe operation of the airplane.

Letting a passenger fly would most likely be listed as a "contributing factor" by investigators looking into an accident where this happened, but responsibility for the crash lies squarely on the PIC.


How do the cockpit controls of a tiltrotor aircraft work?

This video explains it nicely starting at about 1:20 in.

Also see here.

This is a pretty interesting article on flying it as well. It really seems to depend on mode but its summarized here nicely,

  Climbing into the front seats of the Osprey definitely does not
  produce the most graceful entrance: it requires some contorting around
  the armrest, center console and overhead panel. The cockpit is
  dominated by four night-vision-goggle-compatible, six-inch-square
  multi-function displays that allow access to flight, navigation and
  system information. Mechanical flight controls consist of a center
  control stick, thrust control lever (TCL) and rudder pedals. The
  control stick functions as cyclic control while in conversion and
  helicopter modes, but steadily fades into a traditional airplane
  control stick as the nacelles transition to airplane mode.

  The TCL
  moves fore and aft just like an airplane throttle, unlike a helicopter
  collective. It does operate as a collective control, however, and
  becomes a traditional throttle during the transition. While this may
  seem counter-intuitive to helicopter pilots, it actually makes a lot
  of sense, because regardless of the mode of flight, youre always doing
  the same thing: controlling the thrust vector. Forward on the TCL in
  helicopter mode is the same as raising the collective in a helicopter,
  and vice versa. The first couple of hours for helicopter pilots
  transitioning to the Osprey highlight a bit of collective dyslexia,
  but very quickly it never becomes a further problem. A spring-loaded,
  knurled rotary knob on the TCL that lies in contact with the pilots
  left thumb controls the nacelles. Roll the thumbwheel aft and the
  nacelles rotate to the vertical, roll it forward and the nacelles
  continue to the downstops. The controls follow the hands on throttle
  and stick, or HOTAS, concept, and have all the controls necessary on
  them to control multiple systems on the airplane.


How do you request a "pop up" IFR clearance?

Assuming you are not already talking to ATC:

You: Houston Center, Cessna 1234X, request*

Center: Cessna 34X, Houston Center, go ahead

You: Cessna 34X is a 172/U, 35 North IDU, 4500 ft, request IFR to Austin

Center: Cessna 34X ident, fly heading 270

Center: Cessna 34X is cleared to AUS via radar vectors, climb and maintain 6000 ft, squawk 5634

This is essentially the same as making a request for VFR flight following services with the exceptions:

Your aircraft needs to be legal for IFR.
You need to be rated and current for IFR.
You will receive a clearance.

If you already have flight following and need IFR, the controller has you on his scope and already has a strip for you, and you just need to ask him to make you IFR.  In that case he will just put you on an IFR altitude and give you a clearance limit and route.

*As noted in the comments, you may decorate this call with something identifying the nature of your request


How does a pilot aim for an aircraft carrier?

Hopefully this is a better view of what one should see on approach to a carrier.

Above is a typical textbook case approach to a carrier in an F/A-18E strike fighter. I chose a picture at dusk as it is a little easier to see all the symbology and optical lights more clearly.

Note the jet is aligned with the centerline of the landing area. The optical landing sight or 'ball' can be seen to the left of the landing area with the center amber light aligned with the green row of lights, indicating the jet is on a 3° glide-path and should allow it to touch down between the #2 and #3 cross deck pendants for a good 3-wire approach.

The flight path marker is centered in the 'E' bracket indicating an ideal Angle of Attack for the approach; this is also verified by the amber AoA indexer light to the left of the HUD.

The pilot will do a cyclical scan of the line up, ball and E-bracket, making corrections to the control inputs on each pass. In close, over the ramp, and in the wires this cycle shifts over to a focus on the ball, tracking it all the way to the deck such that touchdown should come as a surprise.


Do any companies offer 'ejection' experiences?

No, there are no companies offering ejection seat experiences, for many reasons:

Cost: Ejection seats are expensive, base costs are somewhere around $100,000 per seat. Seats can't generally be re-used, therefore the cost of an experience is going to be well over that
No platform: There are airplanes that are designed to eject someone and keep flying safely, they are used exclusively for seat testing and not open to the public. Someone would have to develop and build an airplane designed to give a "fighter plane ejection" experience
Ejection is incredibly dangerous: the chances of injury or death are very high. Ejection seat companies have used test dummies instead of humans for decades for this reason
Ejection can lead to life changing health issues: the G forces on a modern seat are at least 12G, and go up from there - they can't be any less or you won't clear the airplane. This compresses the spine and can lead to debilitating, life lasting injury. If your ejection position isn't right you can break or lose a limb
Ejection isn't fun: there's not a pilot or crew member in existence who has used an ejection seat and said "Whoopee! Let's do that again!" Instead they say, if they are capable of speech, "Ow!" or "Please get me clean underwear."

So a company would have to spend tens of millions to develop a system that only rich people would be able to use, still less would want to, and a very precious few would be crazy enough to try.


In a manner of speaking yes (although its highly unlikely). If the propellor on his head can generate enough lift to get his mass off the ground there is nothing to say he cant fly. That does not mean that the flight will be very stable or controllable but it may lift off. Since the animal does not have the equivalent of a tail rotor the torque effect generated from the propellor may spin him around. It does appear there may be flyable toy versions

Although for what its worth there is no identifiable power plant that is spinning this head propellor...


Is the Beechcraft Bonanza Jaguar edition different from any other A36?

@acpilot is right- the Jaguar version of Beechcraft Bonanza differs only in the paint job and interiors. AOPA had run an article when the Jaguar versions were introduced:

Like the Jaguar edition of the Beech King Air C90B offered last year, the Bonanza and Baron will have specially outfitted interiors and unique paint schemes.
... Seats in the Jaguar airplane will use the same frames but have new cushions tailored to look like those found in the Jaguar Vanden Plas luxury car. ... tastefully wrapped the yokes in leather.
On the outside, a special paint scheme has been designed to set the Jaguar airplanes apart from standard Bonanzas and Barons.

and also,

The new soundproofing Beech plans for the Jaguar airplanes appears to work well in the rear of the airplane.

Looks like the only differences were the paint and interiors designed by Jaguar specialists:

Jaguar Cars' automotive stylists designed the paint and interior for these packages. Inside, they applied more and finer hardwoods — including a polished Jag-logo inlay on the right yoke — better carpeting, and the finest leathers from Jaguar's own vendors. Outside, the Jag-edition Bonanzas ... get a distinctive four-color metal-flake paint scheme finished off with Jaguar Cars' stylized leaping-cat insignia leaping from the vertical stab and rudder.

These are the only differences and everything else is the same. The performance changes if any would come from these- which I doubt. Around the same time, the Continental engines were refined (they were the same 300 hp though), which might have made the aircraft appear different, though there are none.


Why do airlines over-estimate/over-calculate flight times?

Mainly, to improve their image. Though I'm not sure about this specific flight (or airline, for that matter), it appears that over estimating flight time is usual.
For airlines it is better to overestimate the flight times and then claim that they are punctual, rather than correctly say the required time and then be late due to some unforeseen reasons. For example, if an airline says that a flight takes 80 minutes (while in reality, 60 minutes suffices) and then completes it in 70 minutes, the perception will be that the flight is early. After all, nobody is going to check the exact time required for flight.
In general, the airlines would add some extra time to cater for things like tarmac congestion, holding time, connecting flight etc. However, it appears that the airlines are increasingly padding their 'block times' (which includes estimated flight time, taxi time at both ends, and time for short delays) in order to appear punctual.
This report by USAToday points out that (in US) more flights were arriving early than late (in 2012) and it appears that the trend remains the same. The report points out:

The average flight from Boston's Logan airport to New York's LaGuardia took one hour in 1995. In 2012, it took 75 minutes.
Yet the Logan-to-LaGuardia early-arrival rate soared to 38% last year from just 2% in 1995 as Delta and US Airways added nearly 20 minutes to the schedule.

This makes the passengers think that the flights are on time, though they are actually late (when compared to earlier timing). For example, U.S. Department of Transportation considers a flight as 'on time' if it arrives at its destination within 15 minutes of the scheduled arrival time and without being diverted or canceled and can penalize chronically delayed flights i.e. if they are more than 30 minutes late 50% of the time.
There are other issues here- it takes time to buildup data in specific routes and airlines are cautious in the meantime, airports are getting more and more congested making the total flight time to increase etc., but even taking these into account, it is better for airlines to overestimate than underestimate.


What's on the upper deck in the picture (circled) of Cathay Pacific Cargo Boeing 747-8F?

What's behind those windows is the crew seating and rest area.

There are no passenger seats on those planes, the seats are specifically for the pilots and the people handling the cargo.


What is the difference between component service and inspection?

Servicing is lubrication or replenishment as required for a component to continue in service - greasing, adding oil etc.  Inspection is verification that condition of a component is acceptable, either visually, or using an enhancement method like Xray, ultrasonic, or various non-destructive test methods.

Overhaul/Restoration is disassembly, inspection and replacement of internal parts to bring the unit to some minimum dimensional/performance standard.

The term Restoration is generally associated with MSG-3 based maintenance programs and is something like overhaul but often is restricted to specific components identified in endurance testing, or even just something like a grease charge that requires disassembly to remove/replace, again based on endurance testing.

A restoration doesn't "zero time" a unit; it's more of a mid-life refresh.  MSG-3 based parts can be run forever theoretically, because the whole idea is you run the component until periodic functional testing in the field detects a performance degradation, but parts usually also have a structural life limit imposed on a root component like a housing, based on endurance/fatigue testing.  Once the root component reaches its life limit, the part is scrap.  That clock does not get reset by rebuilding the unit.


Why did the pilot in this EC135 crash change the throttle setting after encountering wake turbulence?

It's the second sentence on the first page of the report:

He inadvertently rolled the throttles to manual, and never restabilized the
engines or main rotor rpm.

Supplemented by (the next sentence):

In addition, he did not understand the reset procedures for the
engine controls (FADEC), and never returned the engines to FADEC control.


If Floyd Bennett Field failed due to its remoteness and isolation, how has JFK been so successful?

If remoteness killed Floyd Bennett, why hasn’t it killed JFK?

Because remoteness did not kill Bennett.

The opening of LaGuardia airport in 1939 absorbed all the traffic, then in 1941 the Navy took over Bennett and banned all commercial and GA flights. After WWII it was meant to return to commercial service to handle the excess traffic from LaGuardia.

(Idlewild was still being built – bigger land area, longer-runways potential, hints of the jet-age in the air, etc.)

But the Port Authority and the Navy could not agree on the cost of moving the Navy's facilities.

  The controversy between the Port Authority and the Navy that has kept commercial traffic out of Floyd Bennett Field in Brooklyn narrowed down yesterday to a \$450,000 question of price. The Navy is asking \$1,200,000 to transfer its facilities and the Port Authority is standing by its statement that it could not spend more than \$750,000 for that purpose. (nytimes.com, 1947)

Further reading: https://en.wikipedia.org/wiki/Floyd_Bennett_Field#History


Do I need to keep my foreign based PPL after passing an FAA instrument checkride?

Adding an instrument rating doesn't change the fact that your FAA private certificate is foreign-based. The IR is an add-on to a pilot certificate, it isn't a certificate itself. If you don't keep your foreign license current then you can't fly on your FAA foreign-based certificate.

To get rid of your foreign-based certificate, you can either do a regular FAA private checkride (including the written exam) or get an FAA commercial certificate (which replaces your private one). In both cases you'll also need an FAA medical to replace your foreign medical.

Source: I did an FAA IR while holding a foreign-based private certificate. I later did the private checkride to get a 'full' FAA private certificate. See this answer for a few additional details on going from foreign-based to 'full'.


How do I compute thrust of a rotor disk and the necessary power to drive it??

Use this formula:

(From Wikipedia entry https://en.wikipedia.org/wiki/Disk_loading). Where P is the power in watts, T the thrust in Newtons, A the disk area of the rotor in sq. meters, and rho the air density in Kg/m3, around 1,22...


The answer to all of our questions is broadly yes, but to break it down:

This company makes mic's for the Bose ANR audio headsets (quiet comfort line) that may fit your use case.

You should be able to use a step up adapter to plug any standard aviation headset into 3.5 mm. It might be worth noting that many of the headsets out there now have bluetooth that you can bus audio through including the mic audio for talking on the phone. However its worth mentioning that most aviation ANR headsets are bulkier than your typical ANR headphone as they also offer passive isolation should the batteries die.

AA batteries are the chosen option as they can be easily sourced just about anywhere and quickly replaced. Some people may chose to use rechargeable ones. I would think the lack of battery options has more to do with the fact that for a situation beyond regular old batteries many people may opt for the panel power variants.

FWIW the audio quality (for music) is decent but not headphone quality on my zulu 3 as most aviation headsets are designed to work well in the voice range and not necessarily the full frequency spectrum range that a set of headphones will work well in.


What is the proper procedure after a bird strike in a single engine plane during takeoff?

You will not find a "single rule fits all" but in general, on PPL training, you are taught < 700 feet, land ahead no matter what.

A skilled pilot, with good currency, in an aircraft they know well, in good conditions they have planned for and with enough altitude, might successfully turn around.  Another pilot in the same aircraft with the same conditions might kill themselves.

The consequences of getting a turnaround wrong are worse then getting a straight ahead landing wrong and, by turning around, you might very well put someone else at risk.  You have much better prospects mushing down straight and level into those trees ahead than stalling out of a turn in an attempt to get back to somewhere you may or may not make.

Forget the flight sim heroics.  Nose down aggressively for best glide (you should already know what that looks like!), then start looking, or even better, go for the area you know is good because you pre-planned for an EFATO.

Bottom line, when you do start training (good luck!), do whatever you are trained to do.


What is the difference Between Minimum fuel and Mayday Fuel?

The term Minimum Fuel should be used when you currently expect to land with more than the minimum fuel reserves (so everything is OK right now), but any further delay would result in being below minimum reserves when landing. This situation is not yet an emergency and ATC does not need to give you any priority, but they know that keeping you in a holding pattern could result in you declaring an emergency.

The term Mayday Fuel should be used when it is clear that you will land with less than the minimum fuel reserves. This constitutes an emergency and requires ATC to act immediately (this could be priority for landing or diverting you to a different airport, if available).

The ICAO defined both terms in Amendment 36 to ICAO Annex 6 Part I:

  4.3.7.2.2 The pilot-in-command shall advise ATC of a minimum fuel state by declaring MINIMUM FUEL when, having
  committed to land at a specific aerodrome, the pilot calculates that any change to the existing clearance to that aerodrome may
  result in landing with less than planned final reserve fuel.

  [...]

  4.3.7.2.3 The pilot-in-command shall declare a situation of fuel emergency by broadcasting MAYDAY, MAYDAY, MAYDAY,
  FUEL, when the calculated usable fuel predicted to be available upon landing at the nearest aerodrome where a safe landing
  can be made is less than the planned final reserve fuel.


How do I estimate how much air flows through the intake due to engine suction?

Okay, to solve this I assumed the atmospahere is ISA and flying at 0ft.
Also that air suction vary linear proportional to mil thrust.

So that airflowThroughAirIntake = factor*thrust

I then did some flight tests to estimate what that factor would be, getting the ratio from the graph at full mil thrust.


It's not too logistically complicated on its own.  You just stop takeoffs, start taxiing the conga line of waiting airplanes to the new runway, let airplanes currently on final land, and start vectoring the other airborne flights toward the new approaches once the last of takeoff traffic is away.  Once the new landing flow is established, start releasing the takeoffs.  This will require coordination between tower and approach and may involve the center if flights need to be put in holding during the transition (depends on how busy the airspace is).  In certain busy airspace this may also require coordination with other nearby airports.

With that said, some airports that take off and land on different runways can have impacts on arrival rates in different configurations, and this adds to the logistic complication.  One example is KIAH, which in normal flow is taking off on the 15's and landing on the 26's and 27.  It isn't too much trouble to switch landing traffic to the 8's and 9, but if takeoffs have to be switched to 33 then the flow rates are negatively impacted.  It gets even worse if landing and takeoff traffic have to be put on the same runways.  How the arrival and departure flows are impacted (if at all) from a runway switch will depend strongly on the specific geometry of the runways.

Anecdotally, the logistic impact of reduced arrival and departure flow is probably the largest impact.  At KIAH they will run their normal flow until the wind gets so bad that pilots start refusing clearances for tailwind limitations, and only then will they switch the departures to northbound.  Similarly, as soon as the tailwind is legal, they'll switch back to southbound departures.


What are good ways to gain experience and flying hours?

There are a few ways to do it.

As has been mentioned many people here in the US are flight instructors (my instructor is building hours to go commercial eventually).

As has also been mentioned you could build hours taking trips with friends and splitting the cost but even split 3 or 4 ways this can get expensive fast.

You could do things like tow gliders or banners if they have that kind of advertising near you. It's not glorious and I can't imagine it's that fun as far as flying goes but it will build you hours.

I'm not sure how to get into flying planes for sky diving tours but that is another option to just build hours.

Again your hours may be an issue but you could look into ferrying planes for people. This can be tough if you don't have a lot of experience in different planes.

These are just a few things that come to mind. There may be varying laws in your area so its worth checking up on that before trying any of these things.


Are there any IFR training plugins / addons for Microsoft Flight Simulator or X-Plane?

Both sims allow you to do a review of your flight where you can see both plan views and vertical profiles of the flight to analyze the results.  This can be especially useful when analyzing the results of attitude instrument flying like A and B patterns, etc.

CloudAhoy does allow integration of flights from X-Plane for review as well.

ATC is a bit better in games like FSX and Prepar3d, but I’d guess there are live ATC available in realistic multiplayer sessions of X-Plane as well.

One real pain in the butt about those Sims is just how out of date they are in terms of navigation databases, etc.  you really can effectively simulate approaches if you can load and practice the latest ones.

That being said the games are excellent to practice basic attitude instrument flying in as computers can simulate that very well sans the vestibular distractions which accompany flying in IMC.  You can also practice partial panel and other IFR emergencies here as well.


What determines the "hang point" and control bar position of a hang glider?

What is the relation between Center of Pressure (C.P.), Aerodynamic Center (A.C.), "hang point" (the point where the flexible "hang strap" connects to the glider, or the point where the "trike" unit is connected to the wing), and the control bar position relative to pilot's body, if the glider is to fly well, meaning that when I lift hands from bar, the glider will not pitch.

a) It is important to note that this is a question about trim, not stability.  We are not asking what will happen to the glider after a disturbance.
b) This answer will address the question in terms of Center of Pressure, not Aerodynamic Center, which simplifies things because we don't have to worry about a pitching moment coefficient.  Note however that the Center of Pressure is not fixed.  In general, the Center of Pressure of the aircraft as a whole moves forward as angle-of-attack is decreased, and moves backwards as angle-of-attack is increased.  (Otherwise the glider would be unstable.)
c) We'll assume that the drag on the pilot's body is negligible, i.e. that the "hang strap" hangs straight down when the pilot is not pulling or pushing on the control bar.
d) In the simple case where the hang strap is connected to the glider right at the CG of the glider, or somewhere along a vertical line passing through the CG of the glider, then in order for the glider to be trimmed to fly hands-off, a line drawn through the Center of Pressure, parallel to the Net Aerodynamic Force vector generated by the glider, must pass through the CG of the glider.  Since the Net Aerodynamic Force vector-- the vector sum of Lift and Drag-- must be vertical in a wings-level steady-state glide, this means that the Center of Pressure must lie somewhere on a vertical line passing through the CG of the glider.
e) In the case where the hang strap is connected to the glider somewhat forward or aft of the CG of the glider, then the following must be true: the torque about the CG created by the G-loading on the pilot's body must exactly counteract the torque about the CG created by the Net Aerodynamic Force acting at the Center of Pressure.  If glider's CG is ahead of the Center of Pressure, then the hang strap must be connected to the glider behind the glider's CG.  If the glider's CG is behind the Center of Pressure, then the hang strap must be connected to the glider ahead of the glider's CG.  Alternatively we could tackle the problem by computing the torques around the Center of Pressure rather than around the glider's CG-- we'd get the same result, because we are free to choose any arbitrary pivot point in torque calculation problem.  We'd just have to remember to adjust the force acting at the CG according to the G-loading, in any case where it is other than one.  Note that in the case where the weight of the glider itself is negligible compared to the weight of the pilot-- which is not a bad approximation for some of the lighter "floater" hang gliders-- this reduces down to the simple statement that the hang strap must be connected to the glider somewhere along a vertical line that passes through the glider's Center of Pressure.  In other words the (center of mass of the) pilot's body must be located somewhere along a vertical line that passes through the glider's Center of Pressure.
f) If your meaning of "if the glider is to fly well" is meant to imply not just that the glider is flying at "trim", but also that the glider is statically stable in pitch, then we have the added requirement that if the angle-of-attack increases, the Center of Pressure of the whole aircraft must move aft, and if the angle-of-attack decreases, the Center of Pressure of the whole aircraft must move forward.  This is accomplished largely through washout near the wingtips.  The wingtips, being aft of the CG and having a lower incidence than the wing roots, essentially act like the horizontal tail of a more conventional aircraft.
g) Actually, the above comment is only true when the "hang point" is not far below the CG.  If the hang point is well below the CG-- as was the case in some early hang gliders where the hang point was some ways down on the triangular control frame, well below the "keel"-- then "pendulum stability" could in theory keep the glider stable in pitch even if the "Center of Pressure" were completely fixed as angle-of-attack changed, or even if it moved a little bit in the "wrong" direction-- at least at angles-of-attack not higher than the angle-of-attack that yields best L/D.  Example-- angle-of-attack decreases, L/D decreases, Net Aerodynamic Force vector points further aft relative to flight path and also relative to glider, apparent G-load on pilot (opposite in direction to Net Aerodynamic Force vector) points further forward in glider's reference frame, and this changes the direction of the force exerted by the pilot's body on the glider, acting at the hang point (if pilot is flying hands-off the control bar).  Glider tends to pitch up to a higher angle-of-attack.  Note that we've phrased this description in such a way that we need not assume the G-load is 1G, acting purely vertically.  Note also that this effect is further magnified if the Center of Pressure is high above the CG of the glider itself.  And finally, note that we can reach all the same conclusions, at least in the case where the pilot's hands are free of the control bar, if we ignore the direction of the G-load vector and only consider the direction of the Net Aerodynamic Force vector, which acts at the Center of Pressure, so long as we choose the C.G. of the whole system as the pivot point for our torque calculations, calculating the C.G. of the whole system based on the assumption that the pilot's entire mass is concentrated at the "hang point".

Does hang glider change stability from stable to neutral to unstable when man move his body fore and aft?

Ideally no, at least within the limits of how far the pilot's arms can reach. But in some cases, yes.
Normally in aviation we are concerned with instability when the CG of the system is too far aft.  I'm not aware that this has ever been a problem in actual practice with any flex-wing hang glider.
Some hang gliders can become unstable at high airspeed, so that above a certain airspeed threshold, at progressively higher airspeeds, the pilot must exert progressively less aftwards force on the control bar, or in extreme cases, progressively more forwards force on the control bar, to hold the airspeed constant.  Generally speaking this is caused by flexing of the structure under the aerodynamic load associated with high airspeed.  Certainly if once some threshold airspeed was crossed, the pilot then had to maintain a progressively less forward or further aft body position to hold the airspeed constant at progressively higher airspeeds, that would be clear evidence that the glider was flexing in a way that fundamentally changed its stability characteristics and moved its "Neutral Point".  And this does in fact happen in some cases.
Keep in mind though that "stability", even static stability, is somewhat hard to define in hang gliders.  Do we mean that the glider will return to equilibrium after a disturbance if the pilot exerts a constant force with his muscles on the control bar (including the case where the pilot is exerting zero force), or that the glider will return to equilibrium after a disturbance if the pilot exerts whatever force through his arm muscles is required to lock his body in a constant position relative to the glider (in which case the glider and pilot can be treated as a single rigid body)?  Note that changes in the L/D ratio, which change the direction of the net aerodynamic force generated by the glider, and thus the direction of the G-loading acting on the pilot's body, will change how far forward or aft the pilot's body tends to "hang" relative to the control bar when the pilot exerts no muscle force, so these two definitions of stability clearly are not the same.  In some cases involving rather steep dive angles, as angle-of-attack is progressively decreased and airspeed is progressively increased, the pilot may experience a need to exert a progressively less aftwards force or in some cases even progressively stronger forward force (the opposite direction that we really would desire to be the case) on the control bar to keep the glider's airspeed constant, yet the pilot's body position is actually being moved progressively further aft (which is equivalent to moving an aircraft's control stick further forward, and is intuitively consistent with our concept of a stable of aircraft.)  A hang glider pilot would typically describe this as "a loss of normal bar pressure", yet the relationship between bar position and airspeed may remain "normal", with the bar having to be placed further aft to reach higher airspeeds.
It's complicated-- some force vector diagrams are really needed to make the point completely clear.  But in short, the relationship between "control stick position" and "control stick pressure" is less straightforward in hang gliders than in most "conventional" aircraft (with unboosted mechanical control linkages).


Which way should I rotate the propeller of a C172?

Almost everyone in the industry has opinions about this, sometimes with good reason. I know knowledgeable people with good arguments for why you should only turn the prop backwards, never turn the prop backwards, or why it doesn't matter either way.

In any case, the issues of concern are primarily:

The engine firing and rotating the propeller, or
The dry vacuum pump sustaining damage.

Those who say "you should never turn a prop forwards," will typically argue that:

Rotating the prop in the firing direction can cause the engine to fire, if:

A magneto (with an impulse coupling) is live (faulty ground or actually switched on), and
The cylinder still has a burnable fuel/air mixture (particularly if recently not properly shut-down).

Rotating the prop backwards eliminates the possibility of the impulse coupling catching and sending a spark to any cylinder.

Those who say "you should never turn a prop backwards," will typically argue that:

Dry vacuum pumps are fragile and only meant to be turned in one direction (with normal engine rotation), and
Rotating the prop backwards introduces the possibility of damaging the vacuum pump's (relatively) delicate carbon vanes leading to pump failure.

Those who hold that either direction is potentially dangerous but can be done with caution will typically argue that:

Backward movement of the prop—especially small, gentle, cautious movement—introduces little likelihood of damage to the vacuum pump vanes;
Good engine shutdown and magneto switch policing will very nearly eliminate the possibility of an inadvertent cylinder firing, and
Carefully moving the prop forward while treating the engine as live will give you a good margin of safety.

One may present a variation on the above, but I think those three perspectives capture the essence of any argument on this topic. Inadvertent engine firing can indeed be very dangerous, and a piston prop should be treated as live and dangerous. Dry vacuum pumps are indeed built with carbon or composite vanes which are far more brittle and delicate than steel parts. However, there are differing takes on just how delicate these are.

"Healthy dry air pump, left, showing graphite vanes angled in carbon rotor. When an air pump fails, its rotor and vanes often shatter" — Photo and caption as seen in Aviation Consumer

The Australian Civil Aviation Safety Authority (CASA) states that:

  Simply pulling the propeller backwards to “test” cylinder compressions may fail the pump by forcing the vanes to rotate in a direction opposite to their intended design. In order to prevent the vacuum pumps from being operated in reverse, never turn the propeller backwards.

However, Aviation Consumer states in this article that:

  One of aviation’s old wives’ tales is that you’ll wreck your vacuum pump if you move the prop backward. Fortunately, that’s not true. While most vacuum pumps are unidirectional—they either turn clockwise or counterclockwise in service based on the direction of rotation of the accessory shaft on the engine (and have CC or CW as a suffice to their model number)—it takes more than a few turns in the wrong direction to cause damage.

Mike Berry, whose opinion on such matters I respect, seems to think that turning the prop backwards will not hurt it, as seen in this quote from his May 2002 article in Light Plane Maintenance, reprinted by AvWeb.com:

  By the way, pulling a prop through backwards will not hurt a dry pump.

I know people that operate and maintain several Cessnas with dry vacuum pumps and are not very gentle when they move the prop either forward or backward they don't seem to have issues either with the engine firing or with low vacuum pump replacement intervals. The vacuum pumps replacements that I have done were typically brought about by normal long-term wear, as far as I can tell.

My take is: firstly, know your aircraft and it's systems. Secondly, be careful; respect the prop. Personally, I turn the prop either direction, but not usually a lot, and I do so gently and cautiously.


One possible source is Skyvector

You can use it like a paper map using the Latitude and Longitude markings to find waypoints (or other positions).

E.g. What waypoints and routes are near S30°0.00' E112°00.00'

Hints: Click "World Hi", use your mouse's scroll-wheel to zoom, play with "Layers".

There are also sites with lists, by region, of waypoints with coordinates. One example is fallingrain


How is the centre of lift estimated for airplane models before they are being mounted in a wind tunnel?

you mount it in a convenient way, and then with all the load sensors reporting, you use a spring gauge to apply known forces by hand to the object in known directions and record the load sensor outputs for each. this will tell you how to add and subtract the individual sensor outputs to yield the correct signals (pure lift, drag, pitching moment, etc.).


What makes a bomber able to deliver nuclear bombs?

You are right in saying that's all that's needed, with the addition of a strategic or tactical need.

The need for a "special evasion" technique is only needed for aircraft dropping megaton range weapons in an air burst.  Kiloton range weapons could be dropped from altitude with no special evasion required except a lot of speed.  Sub-sonic aircraft would need to be "frisky" in their escape. Read about Tsar Bomba for a good example which demonstrates that even with the biggest bomb ever dropped, a relatively slow, lumbering aircraft can escape.

Even helicopters can drop nukes.

Most aircraft are only tasked to drop tactical, low yield weapons.  The real madness is assigned to subs and missiles.

As the comment above says, I suspect that most crews dropping strategic weapons will not care much whether they survive or not.


Would it be feasible to build a jet fighter plane based on a wooden construction?

The wings and a few parts of the body of the Heinkel He 162 jet fighter were made of plywood.
https://de.wikipedia.org/wiki/Heinkel_He_162#Konstruktion_und_Ausr.C3.BCstung

The Bachem Ba 349 'Natter', a rocket-powered interceptor, was built almost entirely of wood.  https://en.wikipedia.org/wiki/Bachem_Ba_349


What construction standards are used to increase impact survivability of passengers in case of a crash landing?

In the US, the FAA has no requirement for crash integrity or safety of the air-frame (and they have been heavily criticized for this). There is no requirement for crash analysis like is done for automobiles. The only requirement is the seat integrity. From 1988 to 2009 the FAA has phased in the requirement for the seat and restraint system to remain secure - from 9G to 16G. New York Times

This is similar to the question,
"Why are passengers not given the option of shoulder harnesses?"

[Safety Report]


Is MIL-PRF-5606 H flammable at 350 deg C?

Both Skydrol and 5606 will burn, though the original 5606 had a much lower flashpoint. However, there are modern derivatives of 5606 such as MIL-PRF-87257 that are within 10-15C of Skydrol's flashpoint and don't suffer the major drawbacks of Skydrol. The US military has switched to MIL-H-83282 which has a flash point, fire point, and spontaneous ignition temperature more than 200°F above 5606.

There are at least 5 flavors of Skydrol (and several for 5606) so it is a bit confusing to generalize "Skydrol" but Skydrol 500B has a flash point of 177 °C (350°F) compared to 5606 at 104°C(219°F). MIL-PRF-87257 very nearly matches Skydrol with a flashpoint of 170°C(350°F).

The two main drawbacks to Skydrol is it is extremely corrosive and much more harmful to human contact. 5606 and it's derivative MIL-PRF-87257 smell nicer and are less likely to attack rubber and plastic. One major disadvantage of 5606 is over time moisture will form condensate that oxidize aluminum tubing. This is one reason aircraft owners are told to regularly fly their aircraft; this prevents long term moisture bubbles eroding a spot in the aluminum line.

source - The US military considers the 5606 derivative MIL-PRF-87257 to more closely meet it's needs than Skydrol.


Why didn’t the space shuttle have flight control manual-reversion capability?

The biggest reason (as is typically the case with space craft) was likely weight. It costs quite a bit of money to get even small amounts of mass into space, when talking about a vehicle keeping it light while maintaining a basic level of safety is key.

Unlike the 737 the shuttle lacked the yoke style controls that would be required for this kind of a system. The shuttle stick not only operated the flight control surfaces while on approach but also drove the reaction control system while in space. So there would be no way to operate a manual backup system even if there was one (without changing all the control surfaces).

The orbiter also had a triple redundant hydraulic system which was considered fail safe enough, and due to the highly automated flying of the orbiter hydraulic systems proved to be what was needed to make the system a reality. Cable controls for manual reversion in a flight regime barely flyable by humans would have largely been dead weight.


Why do pilots refer to the Flight Service Stations as "Radio" in the the United States?

"Radio" is just a shortened version of "Aeradio Station" which was the term used before "Flight Service Station".


How does a US registered pilot obtain approval to fly to Cuba?

To obtain approval to fly to Cuba you must first sumbit an application for an OFAC (Office of Foreign Assets Control) License through their Cuba Travel website or by mail:

Office of Foreign Assets Control
U.S. Department of the Treasury
Treasury Annex
1500 Pennsylvania Avenue, NW
Washington, DC 20220

Once you have your OFAC license, that completes your US legal requirements, as far as I'm aware.* There are other requirements that you have to fulfill to receive a Cuban visa upon entering, but since you have asked about obtaining US approval I haven't looked into that in detail.
For the record, this is the same method that anyone would use to travel to Cuba. Pilots flying to Cuba must ensure that all their passengers also have their own individual OFAC license.

* I am not a lawyer. Please do not consider this to be legal advice. I would recommend calling OFAC and inquiring for further help with the process.

Sources:

Cuba: What You Need To Know About U.S. Sanctions Against Cuba - OFAC
OFAC Contact Info