To enter the climb, it's power, attitude, trim. That is, start by setting climb power, as you already know. Remember to compensate for adverse yaw with the rudder. Immediately raise the nose to the climb attitude. Your instructor will teach you to recognise what this looks like in your aircraft: e.g. there might be a part of the dash that lines up with the horizon. Your airspeed will drop away to the desired airspeed for the climb: usually the best-climb speed. Once you're stable and balanced, at the correct airspeed, use the elevator trim to remove the need for pressure on the stick (or yoke).

To level off from the climb, it's attitude, power, trim. Start by lowering the nose to a level attitude. You need to start doing this before you reach the desired height, as it takes a few seconds to level off. Once you're level, the airplane will speed up. When you reach cruise speed, reduce the power to cruise power, and compensate for adverse yaw. Again, once you're stable at the correct speed, trim away any constant pressure on the stick.

A gliding or powered descent is similar. Power, attitude, trim to enter the descent. First set the reduced or idle power, and wait for your airspeed to decay to the correct airspeed for your descent. When you reach this airspeed, lower the nose to the glide attitude. Once the attitude and speed are stable, trim the aircraft.

To level off from the descent, it's power, attitude, trim again. Anticipate reaching the height you want, just like when climbing. Raise the throttle to cruise power. Adding power will naturally cause a pitch-up tendency in most airplanes, so let the nose come up to the level attitude, and then you'll need forward pressure on the stick to keep it there. Once you're stable and level, trim away that forward pressure.

So for most of these attitude changes, the sequence of events is power, attitude, trim (PAT as a mnemonic). Leaving a climb is different: there it's APT, because lowering the nose first lets the speed increase to the cruising speed before you need to touch the throttle. Whenever you change power, you'll need to use rudder to compensate for adverse yaw.

Generally, you maintain the correct rate of climb or descent by keeping the correct airspeed, not by looking at the vertical speed indicator. Usually you just want the best rate of climb or descent, and you'll already know what airspeed achieves this, so it's easy to just check the airspeed indicator every so often and pitch up if you're too fast, or down if you're too slow. There are circumstances where you need to keep a particular rate of climb or descent, but that's not the norm so it's not what's taught first to student pilots.

The Pilots' Operating Handbook for the aircraft you're flying will tell you when carb heat is needed. In general, you should have it hot when you're at idle or low power (i.e. in the descent), and cold the rest of the time.


An IF is any fix between the IAF and FAF, so as a matter of logic, the same fix cannot be both an IAF and an IF at the same time. Therefore the label IAF/IF must mean it can be either one or, in some cases, both at different times.

If you are cleared to ACZUP for the straight-in approach, then ACZUP is the IAF only. You never pass it a second time, so it doesn't get a chance to be an IF.

If you are cleared to HABJE for the approach, then HABJE is the IAF and you do not pass over ACZUP, so it is neither IAF nor IF.

Otherwise, ACZUP is the IAF when you pass over it outbound, then you do the Hold in lieu of Procedure Turn (HiloPT), and then ACZUP is an IF when you pass over it again the second time inbound. The same would be true if it were charted as a PT instead of HiloPT.

In all three cases, MRVIN is the FAF due to the lightning bolt symbol.


Can a commercial aircraft be detected by ATC's / Radar systems if all its engines fail?

In an event of failure of all engines of a commercial aircraft in mid air ...

That would be a very rare event. In the modern cases where this has happened within an ATC area, it has not prevented location of the aircraft so far as I know.

  ... and no secondary backup or generators powering the plane

Even a two-engined airliner has an Auxiliary Power Unit (APU) and a Ram-Air Turbine(RAT). I believe they also typically have 10-15 minutes battery power for critical systems. I don't know if any airliner has ever lost all generators other than in cases where the aircraft was destroyed in flight (e.g. PanAm 103).

  would the ATC still be able to detect the aircraft with accuracy

If an aircraft's transponder and secondary-radar are not operating, ATC would rely on primary radar, which is less accurate, particularly for altitude. They would also ask the pilots for their position over VHF radio and ask other aircraft in the area to locate the aircraft.

Example: British Airways Flight 9

All four engines flamed out due to ingestion of volcanic ash.

  Despite the crew "squawking" the emergency transponder setting of 7700, the aeroplane could not be located by Air Traffic Control on their radar screens.

The pilot communicated with ATC over VHF radio and later restarted the engines.

  The engines had enough electrical power to restart because one generator and the onboard batteries were still operating

Example Air Canada Flight 143 (the "Gimli Glider")

This 767 ran out of fuel mid-air and all engines stopped.

  The 767 was one of the first airliners to include an Electronic Flight Instrument System (EFIS), which operated on the electricity generated by the aircraft's jet engines. With both engines stopped, the system went dead, leaving only a few basic battery-powered emergency flight instruments.

The pilot communicated with ATC Winnipeg and

  First Officer Maurice Quintal began to calculate whether they could reach Winnipeg. He used the altitude from one of the mechanical backup instruments, while the distance traveled was supplied by the air traffic controllers in Winnipeg, measuring the distance the aircraft's echo moved on their radar screens.

So yes, If the aircraft with all engines out is in radar range and ATC are attentive, they can track the aircraft's location.


Why are light aircraft engines so noisy?

Engines could be made quieter by the simple solution of adding a muffler (or silencer as it's called in some places). They are available for many models and can be installed, at an astronomical cost. The parts and labor are actually pretty cheap, it's the certification costs that make it sting so badly. It costs a lot of money to develop and certify parts for airplanes. Mufflers aren't mandatory, and because they are so expensive to install most don't because the costs so outweigh the benefits - it costs far less to buy a decent active noise reduction headset instead.

Propellers are a big source of noise, and there are quieter designs for many aircraft, however they have to be certified with a particular engine and model of airplane and those costs add up.

The current certification rules are there to keep things safe, in some cases they can stifle innovation. It's why we still have carbureted engines with manual mixture controls instead of computerized fuel injection and turbonormalization.

As for what the quietest trainer is I don't think there's a definitive answer as I don't know of a source of light airplane noise measurements, and any airplane can be used as a trainer. Of the certified light airplanes out there that are commonly used for primary training the Diamond DA20 Katana is the quietest I can think of, that's because it is much lighter than the more common Cessnas and Pipers and therefore uses a smaller engine and propeller. Smaller engine and propeller generally means less noise. Turbo-diesel powered airplanes like the Diamond DA-40s are quieter because the turbo muffles the exhaust noise.


Why increase or decrease rudder when using elevator in turns?

Instructors that teach that to students are fools.  You should be using rudder only as required to keep the ball centered - period.  If you are applying rudder to influence the pitch attitude, to "help hold the nose up", this is very very bad, and leads to stall/spin accidents.

Rudder is mostly being used to counteract adverse yaw from the aileron inputs, and to some degree to correct for yawing motions caused by power changes.  But in any case it is strictly used to keep the tail lined up behind the nose in the airstream.  Anything else and you are skidding or slipping in the turn.

If you are in a 30 deg banked turn, and are descending, the total lift from the wings is insufficient; you need more elevator input, NOT top rudder, which creates a slipping turn, which will make the airplane flick over the top into a spin if you stall while doing it.

Don't overthink it. Ailerons to keep the bank angle, elevator/power to control the pitch and altitude/speed, rudder to center the ball; just do whatever it takes.


Is it legal to fly under the Golden Gate Bridge?

No, it would violate regulations unless it was to meet the needs of an emergency.

Don't forget the catch-all regulation about reckless operation; many regulations may be interpreted very subjectively, and I feel that it is safe to say that flying under the Golden Gate bridge would attract a lot of negative publicity and would ultimately be considered something that the pilot of a fixed-wing aircraft would certainly be reprimanded for.

That's not even considering whether the bridge is 500 feet high, boats that may or may not be passing under the bridge, and your question completely truncated the 91.119(b) that lists information for congested areas, which I am almost certain the Golden Gate bridge would be subjectively qualified as.


Are aircraft capable of sustained inverted flight at constant altitude?

Yes they are! Aerobatic aircraft can have symmetrical wing to improve inverted performance. So with these aircraft there is no any problem at all. Other agile aircraft, gliders can fly inverted as well. Of course is far from optimal but possible. Don't forget that lift depends of angle of attack as well. So if you fly inverted angle of attack and drag will be bigger to compensate for a "wrong" wing profile.


When should a pilot use the word "takeoff?"

The word "Takeoff" should only be used when clearing somebody for takeoff, acknowledging your takeoff clearance, or cancelling/acknowledging a cancelled takeoff clearance.

"Departure" should be used in all other circumstances, and as far as I'm aware whoever told you you could use the word Takeoff for VFR was wrong.

Anybody saying the word "takeoff" intends for an aircraft to enter, accelerate along, and then leave a runway in the immediate future: never anything else. Anybody saying otherwise should be immediately directed to the Wikipedia article for the Tenerife 747 disaster.


What are some unique engineering challenges in designing large, widebody aircraft that do not apply to regional/corporate jets?

Technically, designing and manufacturing narrow-bodies does not differ much from designing wide-bodies. Sure, the scale is different, heavier jet engines, larger factories etc, but in principle the engineering issues to be solved are pretty much the same. Airbus' first design, the A300, was a wide-body. Sure, Embraer and others can utilise their experience for designing and manufacturing wide-bodies.

The real challenge is in the size of the market, and in conquering market share. Only Boeing and Airbus make successful wide-body aircraft. The combined deliveries per year for wide-bodies are a bit over 200 for all types, for narrow-bodies over 1,000, gearing up for > 1,100 in a couple of years.

Image source

Industrial issues to be tackled for starting a wide-body plant:

The investment for designing and starting a manufacturing plant are higher: harder to secure capital.
The market size is smaller: securing a number of unit sales equates to conquering a more sizeable portion of the market than with narrow-bodies.
There are two well-established manufacturers with multiple types each, in multiple variations, cornering all segments of the market.

Very hard to compete here. Much better to scale up the regionals into the narrow-body sector, like China did with the C-919.


What knowledge is needed to build a small aircraft?

One way is trial and error. That is how the early pioneers learned it, and building a few models is a good way to learn the basic stuff, too. That would be

Aerodynamics (what forces keep the aircraft in the air)
Flight mechanics (how to control it and make it fly straight by itself)
Structural design (how to make it light and stiff)
Systems (what equipment is needed to operate it)

My next recommendation might sound boring, but reading the federal regulations for light aircraft will cover all those aspects and more. In many cases you will wonder what that particular regulation tries to accomplish: This is your chance to learn! Post a question here and don't give up until you have fully understood why that particular regulation has been added. Yes, this will take a while, but building an aircraft all by yourself is no mean feat.

Last, join the local chapter of the Experimental Aircraft Association or whatever organisation supports experimental aircraft builders in your country.


Could older airplanes be retrofitted with engines with chevrons?

The chevrons do not implicate a particular type of wing or airframe. However, the engine does need to be designed around having the chevrons, since they affect the performance as well as noise. And the engine design certainly can affect the design of the wing.

In reality, chevrons are more likely to be incorporated in an engine design from the start rather than retrofitted later. And a new engine design will probably be for a new airplane design. This could be a totally new plane like the 787. But it could also be a new derivative, like the 747-8 or the 737 MAX.

So while chevrons can be added to the engines on an existing aircraft model, it's much more likely that the aircraft model will be upgraded in other ways as well to accommodate the new engines. Adding chevrons is likely to be part of a design change large enough to justify changes to the aircraft as well.

However, these changes are not really specific to the engine having chevrons. Changes to the wing and airframe will be due to the inclusion of a new engine, not just the addition of chevrons.


Is a jet engine's shaft neutral in the direction of thrust?

Thrust is produced in the compressor; as its blades push the air backwards to compress it, a reaction force pushes the blades forwards. These blades are fixed to the shaft. The shaft has a flange on it which pushes against a similar face on the engine mounting, in an arrangement known as a thrust bearing. This in turn transmits the thrust to the airframe.
A turbofan has extra big blades which push more air backwards, adding to the thrust.
The turbine blades draw work from the exhaust flow which slows it down, so they push against the main thrust and in a simple single-spool design can even require the thrust bearing to face backwards.
Heating the compressed air in between is what makes the thing work at all. Also, the acceleration of air out the back of the combustion chamber creates a thrust reaction against its forward wall. For a pure turbojet, and especially for a centrifugal compressor, this will be greater than the compressor thrust. It might not be as much as one might suppose because the chamber is relatively small.
For supersonic flight, the air intake acts as a shock compressor to generate most of the thrust, while the exhaust nozzle can be made to generate more by expanding high-pressure exhaust against a divergent nozzle. At high enough speeds the spinning bits just get in the way.


How do I clear an aircraft to exit a hold?

This depends on what exactly you want the aircraft to do:

Immediately depart the hold and fly directly to another fix:

  N1234 cleared to 'clearance limit' via direct 'fix' and then as previously filed.

Immediately depart the hold and fly an assigned heading:

  N1234 Cleared to 'clearance limit' via radar vectors. Fly heading 'heading'.

Proceed to another fix after passing the holding point inbound:

  N1234 After 'holding fix', cleared to 'clearance limit' via direct 'fix' and then as previously filed.

Fly the published approach after passing the holding point inbound:

  N1234 Maintain 'altitude' until 'holding fix', cleared 'approach name'.

Altitude

Lastly, add the altitude to any of the above clearances if it is different than the current altitude by adding a climb/descend and maintain  'altitude' clearance.


Why do modern airliners have windscreens which open?

Not all modern aircraft have windows that can be opened. The Boeing 747 for example does not.

On the Boeing 737, the windows can be opened for two reasons:

Emergency Evacuation: When the aircraft needs to be evacuated, there is always a way to escape from the flight deck without going through the cabin. On the Boeing 737, this is accomplished through the windows. From the 737 NG FCOMv2 (1.40.30):

  The flight deck number two windows can be opened on the ground or in flight and
  can be used for emergency evacuation. To open the window, depress the trigger
  and turn the handle back and inboard. After the window moves inboard, move it
  back until it locks in the open position.

  [...]

  Flight Deck Window Emergency Egress

  If the flight deck number two windows must be used for emergency egress, use
  the following procedure:

  open the window
  open the escape strap compartment (above and aft of window)
  pull on the escape strap to ensure it is securely attached
  throw the strap out the window
  sit on the window sill with upper body outside
  exit in accordance with the following illustration.

  CAUTION: Ensure the escape strap is securely fastened to the airplane.

Aircraft without windows that can be opened, have an escape hatch in the ceiling. You can see the 747 escape hatch in the following image from the FCOM:

Smoke or Fumes Removal: If there is a fire in or near the cockpit that cannot be easily extinguished (e.g. fire in the electronics behind the screens), the smoke has to be removed in order to continue to fly the aircraft. This can be accomplished by opening a window. From the 737 NG QRH (8.19):

  Smoke or fumes source is confirmed to be on the
  flight deck:

  Caution! Window should not be
  opened unless the source is
  confirmed to be on the flight
  deck.

  Establish normal holding speed. High
  airspeed may prevent opening the window.

  Open the first officer’s sliding window.

On aircraft where the windows cannot be opened, there is a dedicated system to evacuate the smoke, e.g. from the Boeing 747-400 QRH (8.43):

  Smoke or fumes persists or is severe and the smoke or fumes source is determined to be on the flight deck:

  Pull the smoke evacuation handle. Pulling the smoke evacuation handle when smoke or fumes source is not on the flight deck may bring the smoke or fumes into the flight deck.


Could an electric airliner be aerotowed to cruise altitude by an electric "tug" aircraft?

Yes, a tug would help, but not greatly so. If your goal is zero-carbon air travel, the tug will stretch the possible range, but the result will still be much too low for practical use.

The principle is similar to using a catapult to save the energy needed for acceleration on the ground. This topic was covered here and shows negligible gains. We also have covered the problems of fully-electric airliners and the weight disadvantage of electric engines, so I will not cover this here again.

If we only look at the energy needed to lift a conventional airliner to its cruise altitude, the magnitude of the problem should become obvious. Here, only the tug is electric while the airliner is a normal A320. We have lots of answers with A320 data, and assuming that less fuel is taken onboard since we get some help in climb, the take-off weight used here is 72 tons. Cruise is in 30.000 ft, so we need to lift 72.000 kg by 9144 m. Energy $E$ is mass times height times gravitational acceleration, or 1.8 MWh or 6,456 MJ. Add to that the acceleration to Mach 0.8 which is 240 m/s at altitude and we need $\frac{1}{2}\cdot m\cdot v^2$ = 2,074 MJ more.

The sum of 8,530 MJ is the energy content of 200 kg of jet fuel, but for a realistic value we need to divide that by the efficiency of the jet. The same has to be done for the electric propulsion case, but efficiency is much better here. If we assume an overall efficiency of 80% in case of fully electric propulsion, the electric energy need to lift an A320 to cruise conditions is 10,662 MJ. To overcome drag and keep systems running, we need maybe another 25% more, so the total energy need will be 13,328 MJ.

Let's consider a tug which carries half its weight in batteries and has the same take-off weight as our A320. Its 36 tons of batteries will hold 25,200 MJ of energy which is just enough to bring both of them close to cruise conditions. On its way back it will glide, so we can save the fuel for lifting the A320 up. How much is that? If we assume an overall efficiency of 33% for jet propulsion, the savings are 600 kg or one twenty-fifth of overall fuel consumption over a 5000 km trip.

Even with the better efficiency of electric propulsion, a heroic effort is needed to save a comparatively small amount of jet fuel. It does work, but the gains are small compared to the effort needed - just consider that the turnaround time for the tug is similar to the flight time of our A320, so as many tugs as A320s are needed to make this system work for all flights.


How much do the fan blades of a GE90-115b stretch when the engine is spinning at maximum RPM?

I don't know the exact answer, but it's on the order of 0.100" (i.e. it's more than 0.010" and less than 1.00").  The more interesting part is that it's not just a simple linear stretching. The blades have a twist to them, and at speed they untwist, which is a strong contributor to the total change in length from 0 rpm to redline.


What is the preferred way to slow down an airliner on a long runway?

There are several ways to slow down an airliner:

aerodynamic drag
friction in the wheel bearings
reverse thrust
wheel brakes

and a few even used a brake chute, but that went out of fashion a long time ago. If the runway is inclined, landing uphill also will slow down the aircraft.

Friction and drag you get for free, so I would rely on those first. Since they are highest when the speed is high, use them first until the aircraft is so far down the runway that it would overshoot without additional application of wheel brakes. Use spoilers and leave the flaps down to maximise the deceleration. Only at the end add wheel brakes so you have slowed down to taxi speed when the exit of the runway is reached.

So the best answer is none of the above but:

Coast along with flaps and spoilers out until you need to brake more to avoid an overshoot. Then apply wheel brakes.

The exact way how brakes should be applied depends on their type.


Why did AF447 never return to normal law?

If the system detects anomalies for more than about ten seconds, alternate law becomes locked in for the remainder of the flight.

The system detected a change in the median value of the three airspeed sources of more than 30 knots within one second (it actually dropped from 274 to 52 knots within 3 seconds). That started a process where the system monitors the difference for a verification period (about 10 seconds). Alternate Law was triggered, along with limiting the rudder travel limit (which was not annunciated to the crew). The flight control law would have returned to Normal Law if the median speed value was within 50 knots of the original speed prior to the loss, at the end of the verification period. If the speeds remain outside of those parameters, Alternate 2 is locked on for the remainder of the flight, and the rudder travel limit fault is displayed.
emphasis mine

From “Understanding Air France 447” by Bill Palmer


Are there any Airworthiness Directives for the Boeing 777 that might explain MH370's disappearance?

Are there currently any ADs for Boing 777s which would indicate the potential for catastrophic electronic system failures that might explain MH370's transponder failure and other issues?

No one of the ADs issued for 777s can by itself fully explain all the facts of the final flight of MH370/MAS370.

Basic facts

The aircraft was a 777-2H6ER with 53460 flight-hours and 7525 take-offs and landings
A 777 has three VHF radios, two HF radios and two transponders.
Modern airliners have two main generators, an auxiliary power unit(APU) and a ram-air turbine(RAT) for emergency power. I think the 777 also has backup generators and two independent main power buses.
The aircraft left Kuala Lumpur for Beijing on 8 March 2014 at 00:14 local time with 239 passengers and crew on board.
Communications were normal up to and including 01:19 when someone on board (believed to be the co-pilot) said to ATC KL "Good night, Malaysian three seven zero". This was the point at which ATC control is handed to Vietnamese ATC. After there were no further communications from the transponder, the ACARS system or from the VHF radios.
Malaysian military reported that their primary radar system records do contain information on an unidentified aircraft to the northwest of Malaysia. The timing, position and heading of the unidentified aircraft in this report are consistent with MH370 changing course away from its intended flight path.
MH370 did not arrive at Beijing at 06:30 as scheduled.
A satellite communications system on the aircraft continued to respond  to routine hourly handshakes from an Inmarsat ground station via satellite 3-F1 located at 0.0°N (±1.59°), 64.5°E at a height of 35786 km. These normal handshakes ceased after 08:11, there was an unexplained incomplete handshake at 08:19.
Subsequent analysis of the handshakes is consistent with MH370 continuing into the southern Indian ocean (and somewhat inconsistent with other routes or it being stationary)
Countries within range of the plane's potential flight paths were asked to check their primary radar records for signs of MH370. No country reported finding anything.
No part of the aircraft or its contents have been located and firmly identified.
Many months later, some parts from the aircraft were washed ashore.
Investigators report that the condition, timing and location are consistent
with ocean currents from a point in the south Indian ocean.

Electrical failure hypothesis

Anyone speculating about the fate of MH370 needs to fit their hypothesis to the above facts.

They would have to explain how the failure incapacitated multiple systems within a few minutes and before any of them could be used.

In particular what did NOT happen:

The pilots did not make an emergency broadcast on VHF
The transponder did not squawk any emergency code
The ACARS system did not continue normal communication
The aircraft did not return to KL and follow procedures for loss of communication.
The aircraft did not continue on its planned route
The aircraft did not arrive at any of the airfields a pilot should divert to in emergency.

And what DID happen

The aircraft remained airborne for a further 7 hours.

Therefore the engines continued to run

Electricity was available to a satellite communications system on the aircraft.
The aircraft most likely deviated from its planned route.

AD 2014-05-03

This AD issued Feb 18th was reported on in March in connection with MH370.

But Reuters reports that Boeing stated this AD does not apply to the aircraft used for flight MH370.

If you ignore that and look at the consequences of a fuselage crack in the vicinity of the satellite antenna, you can see that this would not turn off the transponder, would not affect the VHF aerials and, if it caused a slow decompression - does not by itself explain why the crew would have failed to respond to the resulting low-pressure alerts by donning oxygen-masks, contacting ATC and descending to a safe altitude.

Occams razor

A shortage of facts always leads to speculation. Some of which can be very imaginative. The onus of proof is on those producing the hypothesis.

I'm sure there are thousands of hypotheses but, in my opinion, the simplest explanation I've read which is consistent with the known facts is deliberate action by a pilot or persons unknown. This doesn't mean it is the right explanation, just that it seems the most probable to me at the moment.

  Was the aircraft used for MH370 in compliance with all ADs?

We won't know with any certainty until the investigations branch of the relevant regulatory authority publishes their report on the incident. In previous accidents over an ocean, it has, on at least one occasion, taken years before a final report could be written.

Currently, there have been no confirmed reports, that I can find, of an AD that warned of the potential for catastrophic failures and which should have been applied to 9M-MRO and wasn't.


What would happen when the fuel tank of a Cessna 172 became (partial) vacuum during horizontal flight?

The 172S POH, the current version in production indicates:

FUEL VENTING
Fuel system venting is essential to system operation. Blockage
of the system will result in decreasing fuel flow and eventual engine
stoppage. Venting is accomplished by an interconnecting line from
the right fuel tank to the left tank. The left fuel tank is vented
overboard through a vent line, equipped with a check valve, which
protrudes from the bottom surface of the left wing near the wing
strut. Both fuel filler caps are also vented.

FUEL SELECTOR VALVE
The fuel selector valve should be in the BOTH position for
takeoff, climb, landing, and maneuvers that involve prolonged slips
or skids of more than 30 seconds. Operation from either LEFT or
RIGHT tank is reserved for cruising flight.

NOTE
When the fuel selector valve handle is in the BOTH position
in cruising flight, unequal fuel flow from each tank may
occur if the wings are not maintained exactly level.
Resulting wing heaviness can be alleviated gradually by
turning the selector valve handle to the tank in the "heavy"
wing. It is not practical to measure the time required to
consume all of the fuel in one tank, and, after switching to
the opposite tank, expect an equal duration from the
remaining fuel. The airspace in both fuel tanks is
interconnected by a vent line and, therefore, some sloshing
of fuel between tanks can be expected when the tanks are
nearly full and the wings are not level.


If a pilot license is revoked by a country's aviation authority, can the pilot still obtain another license?

It depends on the regulations in force. Usually, depending in the reason for revocation, the pilots can apply for recertification after a set period (usually one year) where they have to go through the whole process again. For example, according to 14 CFR 61.13,

  (d) Application during suspension or revocation.

  ...

  (2) Unless otherwise authorized by the Administrator, a person whose pilot, flight instructor, or ground instructor certificate has been revoked may not apply for any certificate, rating, or authorization for 1 year after the date of revocation.

It appears that these pilots too, can get another certificate after an year. According to Kuwait Civil Aviation Safety Regulations, Part 1,

  1.2.11 Surrender, Suspension or Revocation of License, Certificate or
  Authority

  ...

  3) Unless the order of revocation provides otherwise, a person whose
  License/ authority /certificate is revoked, may not apply for any
  License, certificate or authority before the elapse of one year from
  the date of revocation.


Why did the space shuttle use bias-ply tyres instead of radials?

Simply put, for the weight bearing factor bias-ply is a lighter tire, and when building a spaceship weight is the top concern.

The reason they were thin and single use also had to do with weight, according to NASA:

  Weight: Since weight is of extreme importance, the tires are made with
  a minimum amount of tread to conserve weight, allowing for larger
  payloads. A few pounds may not seem to make much difference, but when
  you add up all of the ways to decrease weight throughout the shuttle
  it can have a significant impact.

When it comes to weight bearing capacity:

  Load-Carrying Capacity

  Advantage: Bias Ply

  Due to their multiple layers, bias ply tires generally have the
  advantage when it comes to load-carrying capacity. Because there are a
  uniform number of plies to support the weight of a vehicle in both the
  tread face and the sidewall, bias ply tires are generally better when
  hauling heavy loads. This is why trailer tires, tractor tires, and
  heavy equipment tires are often bias ply; they can better support
  heavy loads. Radials are available with high load ratings, but the
  weight-carrying capacity requires adding many more plies to a radial
  tire, making them very stiff.

The important line here being "adding many more plies" which will also make the tire heavier (reference above note on weight). It costs in the neighborhood of $10,000 to put 1 lb into space, so if you can save a few pounds on each tire, it does not matter that they cost \$5,660 each; you save by replacing them every time if they are indeed lighter.

  even a single MLG tyre failure would significantly impair the vehicle’s braking capability, which is most emphatically not a good
  thing for something going as fast as a landing shuttle orbiter.

The shuttle has no issue coming to a full stop with a blowout as was the case with the shuttle Discovery in 1985 during the landing of STS-51-D.


What are the advantages of using DC electric power over AC, as e.g. done in the EMB 135/145?

Now, DC is easier to produce than AC and easily to inverted to AC
To produce AC of a specific frequency, you will need one of below

An engine that rotates at a fixed rate.
A variable transmission box that normalizes the rotation rate.
Produce DC somehow then invert it to AC.

Method #1 is used by most American GE diesel locomotives. As a result, when the locomotive is providing AC power to the train cars, the engine needs to run at a fixed rpm, hence can not run at full rpm and full output. For this reason, a lot of other countries have switched to DC bus for train cars, essentially switched to method #3 (e.g. China uses DC600V for the train bus and it is inverted to 220V/380V 3-phase within each car).
Method #2 I believe is used by most airplanes, because fixing the engine at a certain RPM is simply not possible. The variable transmission is certainly not zero weight and is pretty complex and is certainly a point of failure. It seems like some airplane designs are switching to method #3 as well. They didn't switch to #3 earlier simply because aviation industry relatively is slow on new technology (so is the space industry).
Method #3 is basically what everyone else chooses since the beginning of this century, when semiconductor finally makes it cheap and simple and efficient to invert DC to AC. From small gasoline generators and home air conditioning, to electric cars and trains and ships, whenever the frequency of the power generator doesn't match the consumer, using DC and semiconductor power electronics to bridge the gap is the simple choice.
Most avionics are electronics, and most electronics runs on low voltage DC
Except the gyro, the CRT display, and environment control, everything else runs on DC internally. If you use an AC bus, then every device needs its own converter for it's internal working DC requirement. If you need a converter for each device anyway, then why not a DC-DC one and it's lighter and smaller and possibly cheaper?
Changing voltage used to be easier for AC than DC, now it's sort of the other way.
Before semiconductor, the only efficient way of converting voltage is via a transformer, hence AC. But transformers are heavy, which is why aviation uses 400Hz instead of 50/60Hz: transformers for higher frequencies are lighter and smaller. With modern semiconductor power electronics, you can basically convert DC voltages with near-zero weight, which is certainly desirable for airplanes. Also, semiconductor are made from sand, a lot cheaper than copper that makes a transformer.
DC-DC voltage conversion is more robust than AC-AC
An AC power transformer converts the voltage at a fixed ratio, so when the input side's voltage or frequency fluctuates, it propagates to the output, potentially affecting the downstream devices. DC-DC converters and DC-AC converters outputs at a fixed spec, so the input fluctuations are isolated from the output. This additional protection is certainly desirable for the aviation industry where safety, reliability and fault tolerance are the top of concerns.


Why are Oscar, India, and X-Ray (O, I, and X) not used as taxiway identifiers?

Because those symbols are easily confused with the number 0, the number 1 and the symbol for a closed runway/taxiway (✕) respectively.

(1) Numbers  by  themselves,  and  the  letters  "I"  and  "O"  must  not  be  used  because  they could be mistaken for a runway number.
(2) The letter "X" must not be used because a sign with an "X" could be misconstrued as indicating a closed taxiway or runway.

Source: FAA Engineering Brief No. 89 on Taxiway Nomenclature Convention (via SKYbrary.aero).
Most aerodromes do refrain from using these identifiers, but there are also examples of them being used. For example, Copenhagen (EKCH) has a taxiway I(ndia).


How do trainer aircraft differ from non-trainer versions?

The short answer is that there's no real difference between a "trainer" aircraft and an "owner" aircraft when they roll off the manufacturer's assembly line.

Below are two mid-1970s Piper Cherokee Cruisers - take my word for it that they both have virtually identical instruments, avionics, and interior finishing. One of these airplanes is the "trainer" I did much of my early training in, and had a little over 11,000 hours of flight time as of when the school sold it. The other is (probably) an owner-flown airplane with about 2,000 hours of flight time.

Can you tell which is which? The answer is in the spoiler box at the end of this post.

"Trainer" aircraft generally have flight and operational characteristics that makes them "suitable for use in training" -- though what that means is a subject of some debate.

In modern training aircraft you'll almost always find the following:

Dual controls
Much like a Driver's Education car has an extra brake, aircraft used for training will have dual controls so your flight instructor can correct any mistakes the student makes before they become dangerous.  (Dual controls are in fact required for flight training, at least under FAA regulations, though interestingly dual brakes are not required.)
2-4 person seating capacity
Hand in hand with dual controls goes dual seating - You need a place for both a student and an instructor.
You don't generally find many trainers that will seat more than four people, as those larger aircraft cost more to purchase and operate.
Some kind of intercom
Students and instructors generally wear headsets, and an intercom system makes it easier for them to communicate.
One or more Radio systems
Part of flight training includes learning how to communicate with Air Traffic Control and other pilots, and how to use radio navigation systems. This requires at least a communication radio, so there's usually one either installed or available (a handheld unit), and in most modern trainers you'll find one or more navigation radios of various types.

In addition trainer aircraft tend to be inexpensive to maintain (mechanically simple), operate (relatively fuel-efficient), and tend toward the slower end of the speed spectrum (because it's easier for a student to keep up with a slower aircraft).

  It's important to note that not all "trainers" fit this mold: The T-6 Texan is, by designation, a Trainer aircraft, but its goal was to train Air Force pilots, many of whom would go on to air combat roles. The things a T-6 is optimized to teach are very different from what a Piper Cherokee or Cessna 172 are optimized to teach.

Not surprisingly many of those same characteristics are also desirable in a plane you might buy to fly yourself: Dual controls in case you take a friend or another pilot along (or in case you want to take instruction in your own aircraft), an intercom to let you talk to your passengers, and radios so you can navigate and communicate in the air traffic system.
Because of this many pilots who elect to buy an airplane purchase what we would consider "trainer-class" aircraft, frequently models similar to the ones they trained in (and in the used market, frequently aircraft that were used for flight training at some point).

When you leave the "trainer" range you tend to find faster aircraft, more complicated systems, more attractive finishing elements (plush cabin interiors, fancy paint schemes), and more seating capacity.
You also find aircraft that begin to specialize more: Where trainers tend to be well-rounded the "non-trainer" planes tend to excel in specific areas, serving specific niches in the market (the Extra 300 is a high-performance aerobatic aircraft favored by many airshow performers, Mooney aircraft feature extensive speed optimizations and are favored by many pilots who use their planes for long-distance travel, the Piper Mirage is a "luxury" cruiser/transportation aircraft suitable for flying corporate executives to and from smaller airports, etc.).

   N2269Q is the trainer, now sporting a shiny new paint job.
 N32711 is the owner-flown airplane, with its factory paint. (Trade-a-Plane ad)


Does a Type Rating "upgrade" with your license?

The answer to this lies in 8900.1, Volume 5, Chapter 2, Section 18 - Conduct an Airline Transport Pilot Certification, Including Additional Category/Class Ratings.

In most cases, yes the type rating "upgrades" or "elevates" along with your license since the type rating is always evaluated at ATP standards, even if you only have a private or commercial certificate.

Exceptions are type ratings for single-engine airplanes and type ratings that have a "VFR ONLY" restriction.

8900.1 excerpt:

  5-710    PILOT CERTIFICATE LEVEL AND CATEGORY AND CLASS RATING. The following category and class rating(s) for which the applicant has
  qualified on the original or subsequent ATP practical tests are
  entered on the ATP certificate.

  A.    Addition of Lighter-than-Air and Glider Class Ratings. A lighter-than-air or glider category rating may be added to an existing
  ATP certificate; however, the rating may be added only at the
  recreational, private, or commercial pilot certificate level, as
  appropriate to the practical test completed. There is no provision for
  the original issuance of an ATP certificate with a lighter-than-air or
  glider category rating.

  B.    Type Ratings. Type rating tests are conducted to the ATP standard for all grades of pilot certificate. Therefore, all type
  ratings in that category and class of aircraft for which the practical
  test is conducted in are upgraded after successful completion of the
  practical test. For example, a person who holds B-737, DC-3, and SK-62
  type ratings on his or her commercial pilot certificate, and later
  satisfactorily completes an ATP practical test in a CE-750, would have
  his/her B-737 and DC-3 type ratings elevated up to the ATP
  certificate. The SK-62 would not elevate up because the practical test
  was in a multiengine airplane. However, when the person satisfactorily
  completes an ATP practical test in a helicopter, the SK-62 would then
  elevate up to the ATP certificate. Therefore, all of the type ratings
  held on the superseded certificate carry forward at the new
  certificate level within category and class.

  NOTE:  A type rating for a single-engine airplane may not be upgraded
  to the ATP level.

  1)    Except for type ratings and, under some circumstances, the
  instrument rating, other ratings indicated on the superseded pilot
  certificate are carried forward at the commercial, private, or
  recreational pilot certificate level, as indicated on the superseded
  certificate.

  2)    Instrument rating privileges are shown on the ATP certificate
  only if the ATP practical test was conducted under visual flight rules
  (VFR) only, or to retain instrument privileges that were held on the
  superseded certificate for a category of aircraft other than the one
  used for the ATP practical test.

  C.    Type Rating Limited to VFR. A type rating bearing the limitation “VFR ONLY” may be added to an existing certificate other
  than an ATP certificate under the provisions of § 61.63(e). This
  limitation may be added to an aircraft type rating not capable of
  instrument maneuvers or procedures required on a practical test. The
  practical test must be administered under the appropriate ATP PTS for
  an aircraft type rating limited to “VFR ONLY”. A type rating bearing
  the limitation “VFR ONLY” may be added to an existing ATP certificate
  under the provisions of § 61.157(g). The practical test must be
  administered under the appropriate ATP PTS for an aircraft type rating
  limited to “VFR ONLY.”

  NOTE:  There is no provision for taking an initial practical test for
  an ATP certificate in an aircraft that would require a VFR limitation.


What is the minimal landing area required for an EC135 air medical services helicopter?

I don't think there's a hard and fast rule for this, but it depends on a number of factors:

Wind/ Weather conditions requiring safety margins.
Effect of nearby objects/structures. If they are big I think they might cause unpredictable wind effects, again requiring compensation and space.

(source: flugzeug-bild.de)
That said, I'm no helicopter pilot, so somebody else might be able to give a more detailed answer. YouTube is a pretty decent place to find some tight landings though.


Are instrument lights required for night VFR flight in an SLSA?

Cockpit lighting is not required to be present as required Night VFR equipment under Part 91 general flight rules.  That being said, there is the following Part 23 Certification Requirement for external and cockpit lighting.

§23.2530 External and cockpit lighting.
(a) The applicant must design and install all lights to minimize any adverse effects on the performance of flightcrew duties.

Under the terms of this regulation one could make the argument that an OEM applying for a normal category type certificate will need some type of effective cockpit illumination to minimize adverse effects on aircrews.


Why don't all new GA planes include a parachute system?

Airframe parachutes are becoming an increasingly popular option on newly-certificated aircraft, thanks in part to the track record of successful deployments on Cirrus aircraft.

If I had to speculate on why they're not showing up in older certificated designs (like the Piper PA-28 or the Cessna 172 & 182) I'd go with the reason I mentioned in my comment: "New" Pipers and Cessnas are basically extended manufacturing runs of very old designs - going on 50+ years. Changing an existing aircraft design to include the required hardpoints, breakaway panels, etc. for a parachute system would be a substantial change to the type certificate, and under Part 23 certification rules doing so would cost the manufacturer an equally-substantial sum of money for the design, engineering, and testing required.
Light GA aircraft sales at the moment are, shall we say, lackluster -- the additional costs for the engineering, the type certificate update, and the parachute itself would certainly not help matters, as that cost would need to be passed along to the eventual purchaser of parachute-equipped aircraft (which would probably mean putting a 50+ year old classic Piper or Cessna design in the same price category as a clean-sheet Cirrus SR20/SR22).

In addition to the mainly-financial reasons above Quantas 94 Heavy has a point regarding weight.  BRS (the premier airframe parachute company) makes a STC'd kit for some Cessna aircraft.
This kit costs about 80 pounds of useful load, and on many light GA aircraft the useful load is marginal enough that this added weight means you're effectively sacrificing a passenger to the installation. The Cessna retrofit kit also takes up a substantial amount of space in the baggage compartment as you can see from their installation white paper, which is certainly a negative factor as well. Were the chute to be incorporated into the design by Cessna it would likely be installed in a similar location (there just aren't many other places to put it) with a similar cost in weight and cargo space.


The Air Traffic Control system does transmit information over the internet. The Air Traffic Control system has a number of components, some of which transmit information over the internet. According to Review of Web Applications Security and Intrusion Detection in Air Traffic Control Systems, Office of Inspector General, DoT,

  ..Federal Aviation Administration (FAA) has increasingly turned
  toward the use of commercial software and Internet Protocol (IP) -based
  technologies to modernize ATC systems.

Note that the ATC is not connected directly to the internet. It is the behind scene connections, that are routed through the internet. According to a security professional,

  ... when most managers say there is no connection to the Internet, they are unaware of maintenance connections. Behind the scenes there are almost always semi-direct connections through routers shared between the control system and business systems that can be exploited

Actually, the use of internet for sharing of information is increasing. FAA's NextGEN modernization involves a significant amount of information transmission over the internet. According to US Government Accountability Office,

  NextGen is a modernization effort begun in 2004 by FAA to transform the
  nation’s ground-based ATC system into a system that uses satellite-
  based navigation and other advanced technology. ... These
  new technologies will use an Internet Protocol (IP) based network to
  communicate.

Image from GAO report on Air Traffic Control

This increasing connection to the internet does increase the associated risks. From the same GAO report:

  ... the shift to NextGen technologies will require FAA to replace its proprietary, relatively isolated ATC computer systems with information systems that interoperate and share data throughout FAA’s operations and those of its aviation partners. ... These new systems...will also employ digital and Internet-based computer-networking technologies, exposing the air traffic control (ATC) system to new cybersecurity risks.

As to why the ATC is connected to the internet, it basically boils down to ease of operation. According to [NATS], which manages UK airspace,

  We ... are now working all over the world within an industry where systems are connected across organisations, countries and continents.

Such an interconnected worldwide system requires a standard platform, which will not be possible (or atleast very difficult to maintain) if a closed, proprietary platform is used.

So, the ATC does use internet, though this is mainly to transmit information. However, I'm not aware of the security systems, though we can be sure that they do have some sort of encryption (If I'm correct, Lockheed Martin supplies the software) and have firewalls to protect the systems.


Why is there still an Air Berlin branded plane operating as of Sep 5th, 2018?

Paintshops have been very busy in the past year.
So getting a slot to repaint an airplane is not that easy.
In addition, apart from the fact that the livery is not the one of the owner, the plane is perfectly fine.
And while applying a new paint scheme the airplane is not earning money.

What airlines do is, repainting the planes when a longer technical check is due anyways.


When would a pilot request a "VMC descent" or "VMC climb"?

It would be needed when otherwise the flight path would not be cleared because ATC cannot ensure separation with the conflicting traffic. The pilot agreeing to maintain their own separation in VMC allows the level change to be cleared despite the conflicting traffic.


What is the airfoil used in the SB13 flying wing?

According to the Wikipedia Page on SB-13 Arcus, the airfoil used are,

  HQ 34N/14.83 at root, HQ 36N/15.12 at tip. Winglet Wortmann FX 7-L-150/K30


Does a subsequent crossing restriction supersede earlier crossing restrictions?

AIM 4-4-10 (g) gives us guidance on this situation.

  The guiding principle is that the last ATC
  clearance has precedence over the previous ATC
  clearance. When the route or altitude in a previously
  issued clearance is amended, the controller will
  restate applicable altitude restrictions. If altitude to
  maintain is changed or restated, whether prior to
  departure or while airborne, and previously issued
  altitude restrictions are omitted, those altitude
  restrictions are canceled, including departure procedures
  and STAR altitude restrictions.

For the example in the question, unless the controller restated the requirement to cross MARCC at FL180, that clearance is cancelled by the issuance of the clearance to cross BILEY at 13,000.


How high could Concorde potentially reach by going fast and pulling up?

There are a couple of ways to look at this question. The easiest is in first principals.
Therefore imagine that the concord (flying at Mach 2 at FL 600) can suddenly and without energy loss pull up, such that it flies for example 10 degrees upwards. Also we assume the following:

The engine flames out immediately, therefore no engine thrust.
We neglect air resistance

How much higher would it go? The formula to calculate this is suprisingly simple:
$$ \Delta x = 1/2 \cdot \frac{(V_I \cdot sin(\gamma))^2}{g} $$
with $V_I$ being the inital velocity (590 m/s which is Mach 2), $\gamma$ being the climb angle and $g$ being the gravity of $9.81 \frac{m}{s^2}$.
I have calculated it for a couple of angles:

$\gamma = 10°$: 535m
$\gamma = 30°$: 4436m
$\gamma = 45°$: 8871m
$\gamma = 60°$: 13307m
$\gamma = 90°$: 17742m

That gives us a first guess, but the question remains: Could it pull up at this high altitude? The answer is: Yes. Consider the formula to compute the dynamic pressure:
$$ q = 1/2 \cdot \rho \cdot V^2 $$
The concorde takes-off at around $113 \frac{m}{s}$ at an air density of around $1.225 \frac{kg}{m^3}$. The air density at FL 600 is around 1/10th of the air density at sea level. However the crusing speed is roughly 5.2 times faster, which yields 2.7 times higher dynamic pressure at that altitude. Thus, the rudders definitly work at that altitude.
The real limiting factor here are the structural limits when you try to pull up at Mach 2. For example if you try to pull up your aircraft at Mach 2 with a constant acceleration of 1 G, you will follow an circle with a radius of ~50km. Even with 3 G acceleration, you will still follow an (upward) circle with a radius of roughly 16km. My guess is that the Concord can safely handle around 3 Gs (For example to be able to handle gusts at altitude). Additionally, you will loose a lot of your energy while pulling up, due to additional drag (remember, because of the increase angle of attack, the aircraft has more drag) and of course you are getting slower as you trade velocity versus height. Thus as some point you will not be able to pull-up any further because you lost too much speed. I tried to estimate how much higher you would have to fly in order to go down to stall speed1, and my result is 11.2 km of additional height. That would mean that you could reach a $~70°$ climb. However I neglected air-drag etc. and the fact that you will definitly not pull 3Gs at stall speed.
To get a definit answer, one would have to perform some computer simulations. Perhaps one of the popular flight simulations can help. But I would guesstimate, that at FL 600 going at Mach 2, you can probably (safely) pull the airplane up into a climb of around $\gamma = 30°$, which would yield around ~4.4km of additional height.
P.S: However the assumption that the engine will flame out at higher altitudes is probably true. My guess would be that the engine was designed such that it can not substantially exceed FL 600. But that is speculation.
1 I simply assumed that the stall speed is at the same dynamic pressure as at take-off condition. This yields a stall speed of $357 \frac{m}{s}$


How is the term "Coast" defined for FAA regulatory purposes?

Coastline means the territorial sea baseline. In the language of international treaties like UNCLOS, the territorial sea doesn't include internal waters, regardless of their size. NOAA confirms this, notes however also, that not all US court decisions follow that view. NOAA also provides a map to view the US territorial waters & exclusive economical zone, which shows that the great lakes are neither.


The primary reasons large airliner-sized aircraft would stay in formation is for a photo flight, or for reasons related to military operations.
Very few civilian airliner-sized aircraft are grey.
The two grey aircraft are surely military tankers, both of the same type.  The white aircraft is in position to receive fuel from the front aircraft.  Based on color and large size (relative to the grey aircraft), the white aircraft is a 747-based military aircraft, such as a VC-125 (the type used as Air Force One) or an E-4.  With this in mind, the size of the tankers suggests that they are KC-135's.  A close look at the grey aircraft shows that they appear to have engines located well outboard on the wings, i.e. have four engines on the wings rather than two, further supporting this identification.
It is very common for military tankers to fly in a loose "trail" formation like this.  I've seen it dozens of times.  Whenever I see airliner-appearing aircraft flying in this type of formation I always reach for my binoculars and they usually turn out to be KC-135's, KC-46's, or KC-10's.
As to the "why" part of your question, a possible answer might be that two tankers operating together gives both crews a chance to practice refueling another aircraft of some particular type-- in thus case the E-4 or VC-125-- without having to put two different receiver aircraft in the air.  There are many other reasons why the military often finds it advantageous to move several aircraft through the airspace together as a single formation rather than as completely independent flights.
FlightRadar24 is a good resource for answering a question like this-- it allows one to zoom in on a given area and play back tracks from a given time in the past.  Much military traffic is not captured, but one could at least verify the presence or absence of civilian traffic at the time and place of interest.  ASE user DeepSpace has now provided this link, showing that in this case the ADSB transponder of a KC-135R was in fact captured at the time and place of interest.  The flight started and ended in Phoenix, and included two passes over the Hopi reservation.  The reported altitude over the Hopi reservation at the time of interest was 22,075'.


Is there a maximal time to pass a type rating?

Nope.  Not unless your employer refuses to continue training.  Legally all that’s required is that you have accomplished all the training required to meet the prerequisites per §61.39 and meet the practical test requirements per §61.43 plus meet the eligibility requirements for the grade of pilot certificate you are applying for per §61.103, §61.123, or §61.153.


How does a Boeing 737 look like at night from 2000 meters away?

At night, at that range, it will look about like a dot of light, probably with a red flashing beacon and white flashing strobe lights.

That's what you'll see from essentially every aircraft at that range at night, unless the pilot chooses to turn off some or all lights.

But you're seeing the LIGHTS, not the AIRCRAFT, at that distance, and the ability to visually identify what aircraft it is, is essentially nil.


Are these two objects in cockpit of Antonov - AN 225 Mriya fans for air? What is their purpose?

They are indeed "Soviet style air conditioning". You will see them in other Eastern-bloc aircraft too. We even had them in the Shorts Skyvan. They are operated by a simple on-off switch and can be swiveled to point in the direction chosen by the pilots. The fan blades are made of rubber so they won't cause injury if one's hand inadvertently comes into contact with them. In this picture of the Skyvan, you can see the fan (arrowed) and the switch (circled).

Here is another airplane with the ubiquitous Soviet Air Conditioning system, Tupolev 154.


What is the effect of fuselage weight on a model glider?

Variations in aircraft weight do not affect the glide angle provided that the correct airspeed is flown. Since it is the lift over drag (L/D) ratio that determines the gliding range, weight will not affect it.

The glide ratio is based only on the relationship of the aerodynamic forces acting on the aircraft. The only effect weight has is to vary the time the aircraft will glide for. The heavier the aircraft is, the higher the airspeed must be to obtain the same glide ratio.

If two aircraft have the same L/D ratio but different weights and start a glide from the same altitude, the heavier aircraft gliding at a higher airspeed will arrive at the same touchdown point in a shorter time. Both aircraft will cover the same distance but the lighter one will take a longer time to do so.


How do I get an FAA CPL from an EASA PPL?

First, this question covers converting an EASA PPL to an FAA one. Based on what you said, I'd strongly suggest getting a full private license rather than a foreign-based one. That will probably require some flight training, which means you'll need TSA approval.

Next, when you have the private certificate then you can continue to CPL. In the US an instrument rating isn't required for a CPL but most people get it because otherwise the CPL is very restricted. You'll need TSA approval again for instrument training but not for commercial training. If you do multi-engine training at any point that's another TSA approval, by the way.

Assuming you have the time and money for all the training, your biggest issue will probably be legally entering and staying in the US. You need an appropriate visa or green card for flight training, plus the TSA approvals that I mentioned.


What is the pattern of the flashing light in Airbus A340-300?

For the lights on the A340-200/-300 see Documentation page 129.

For the lights on the A340-500/-600 see Documentation page 133.

Use the following link to see the lighting regulations for commercial aircraft -  http://www.whelen.com/pb/Aviation/System%20Requirements/Anit-Collision%20Systems.pdf

Use of lights

AIM 4−3−23. Use of Aircraft Lights was updated in the latest edition.

Guidance about using aircraft lights during ground operations also appears in AC91-73B, “Part 91 and Part 135 Single-Pilot Procedures during Taxi Operations.”

h. Use of Exterior Aircraft Lights to Make Aircraft More Conspicuous.

(1) General. Exterior aircraft lights may be used to make an aircraft operating on the airport surface more conspicuous. Pilots may use various combinations of exterior lights to convey their location and intent to other pilots. Certain exterior lights may also be used in various combinations to signal whether the aircraft is on a taxiway or on a runway, in position on the runway but holding for takeoff clearance, crossing an active runway, or moving down the runway for takeoff.

NOTE: Because adherence to the guidelines in this AC are voluntary and aircraft equipment varies, pilots are cautioned not to rely solely on the status of an aircraft’s lights to determine the intentions of the pilot(s) of the other aircraft. Additionally, pilots must remember to comply with operating limitations on the aircraft’s lighting systems.

(2) Because adherence to the guidelines in this AC are voluntary and aircraft equipment varies, pilots are cautioned not to rely solely on the status of an aircraft’s lights to determine the intentions of the pilot(s) of the other aircraft. Additionally, pilots must remember to comply with operating limitations on the aircraft’s lighting systems.

(2) Exterior Lights. To the extent possible and consistent with aircraft equipage, operating limitations, and pilot procedures, pilots should illuminate exterior lights as follows:

(a) Engines Running. Turn on the rotating beacon whenever an engine is running.

(b) Taxiing. Prior to commencing taxi, turn on navigation, position, anti-collision, and logo lights, if available. To signal intent to other pilots, consider turning on the taxi light when the aircraft is moving or intending to move on the ground, and turning it off when stopped, yielding, or as a consideration to other pilots or ground personnel. Strobe lights should not be illuminated during taxi if they will adversely affect the vision of other pilots or ground personnel.

(c) Crossing a Runway. All exterior lights should be illuminated when crossing a runway.
CAUTION: Pilots should consider any adverse effects to safety that illuminating the forward facing lights will have on the vision of other pilots or ground personnel during runway crossings.

(d) Entering the Departure Runway for Takeoff or LUAW. When entering a runway after being cleared for takeoff, or when taxiing into position and hold, pilots should make their aircraft more conspicuous to aircraft on final behind them and to ATC by turning on lights (except landing lights) that highlight the aircraft’s silhouette. Strobe lights should not be illuminated if they will adversely affect the vision of other pilots.

(e) At Night, and When Cleared to LUAW. Consider lining up slightly (approximately 3 feet) to the left or right of the centerline (CL) to enable a landing aircraft to visually differentiate your aircraft from the runway lights.

(f) Takeoff. Landing lights should be turned on when takeoff clearance is received, or when commencing takeoff roll at an airport without an operating control tower.


Under what conditions can a pilot log simulated instrument time?

It is simply a VFR flight, you need to meet normal VFR requirements plus a qualified safety pilot to watch outside for traffic. I assume this aircraft has the minimum IFR flight instruments not including navigation, and is being used to practice basic instrument attitude skills, otherwise I don't know what the point would be. Flight by reference to instruments implicitly requires instruments to reference; a handheld device can not provide gyroscopic data as these inherently need to be fixed to the aircraft frame.


What are the differences between the CH-46 and the CH-47?

The difference is in mission, and the difference is non trivial.
The twin rotor configuration goes back to the 1960's. ("Flying banana" Piasecki H-21.  The CH-47 replaced it in Viet Nam in 1965).  Chinook became the Army's heavy tactical lift during Vietnam.  Like the C-130, that particular design is timeless.  The CH-47F is the current configuration.  It carries about twice as much as a CH-46 could.  It is also one of the faster helicopters there is (it can fly almost 200kts) though the CH-53E has flown faster.
The CH-46 was an adaptation of the same idea, but made smaller and marinized: it had to meet a host of Marine Corps and Navy requirements to fit on amphibious ships and supply ships. Space and fit are non-trivial limitations when writing requirements for naval aircraft.  (As an aside, the US military no longer operates the CH-46.  It appears that the last CH-46 squadron in the USMC, HMM 774, let go of its last Phrogs in 2015 and is now VMM 774, flying V-22's.  The Navy Sundown for CH-46 was in 2004.)
Not having to take off some power for a tail rotor is an advantage.  The CH-46 mission for the Marine Corps was vertical assault (it carried more than a Huey and predecessors like the CH-34); for the Navy, it was the VERTREP mission.
The payload and maneuvering benefits from the lack of a tail rotor made the VERTREP mission a perfect fit for the CH-46.  One of the challenges in ship borne operations is the ability to run simultaneously resupply by air and ship-to-ship (UNREP) while not being operationally constrained (for the ship drivers) "getting into the wind."  That limitation tail rotor helicopters don't handle as well as the CH-46.  (That point was a core argument against CH-60S as replacement for  CH-46; but that's another matter).  I've flown VERTREP in helicopters with tail rotors; the CH-46 was less constrained than we were.
What about Marine and Navy Heavy Lift missions?
The Marine Heavy lift (analogue to the CH-47 for the Army and Air Force CSAR) is fulfilled with the CH-53, and has been for over 40 years.  The CH-53 can fold its tail to fit on a ship.  Even with folded blades, the Chinook's deck footprint is / was too large(at the time) on the amphibious ships in service.  The Navy VOD (heavy lift) was handled by CH-53's for 40 years.  They have since given that mission to the MH-53E minesweepers.  (Flexible, that's helicopters!)
Smart Requirement Writing led to smart choices
"The Military" would have made a significant mistake "to just make one type" since back in the 60s and 70s, making mission specific aircraft was the way to go.  Quite frankly, it makes for cheaper aircraft to build it for one core mission.  (See the A-10 as a fine example of that).
Note: An early failure in "one size fits all" was the F-111.  A current "one size fits all" example of cost going through the roof is F-35.
At the time the CH-46 and CH-47 were procured, the military was smart: apply the KISS principle to get aircraft that fit mission requirements.  The Army and Navy mission requirements were not identical.
(So how do I know all that?  25 years Navy pilot (helicopters, ASW warfare specialty, did other stuff like Vertrep ...), significant experience in multi-service operations, and a few years having to work in an acquisition job.)


Aircraft fly high because it puts them above the weather. This is at least the historical reason why aviation has desired higher flying aircraft over the years and subsequently driven design that way. When it comes to weather altitude gives you diversion options, avoidance possibilities and in some cases the ability to simply fly over a system instead of through it.

Jet engines are more efficient at high altitudes which makes it beneficial to fly them up there (you can find the full explanation of that in this Q/A) but piston planes can fly quite high as well jets have prevailed for lots of reasons and that is a different discussion all together.

Altitude, in some cases also provides a safety margin for things like loss of engine power. With sufficient altitude you can have an outcome like this instead of this.

As for cabin depressurization that is not really a huge issue. Aircraft are equipped with oxygen masks to keep everyone safe in the event of a depressurization and all aircraft are certified to be able to do a decent from cruising altitude to 10,000ft. (non supplemental Oxygen altitude) in a specified time. Some newer systems will even bring the aircraft down automatically in the event of a depressurization.


The intent of the regulation lies at the beginning, in 61,93(a):

  §61.93   Solo cross-country flight requirements.

  (a) General. (1) Except as provided in paragraph (b) of this section,
  a student pilot must meet the requirements of this section before—

  (i) Conducting a solo cross-country flight, or any flight greater than
  25 nautical miles from the airport from where the flight originated.

  (ii) Making a solo flight and landing at any location other than the
  airport of origination.

Training and an endorsement from an instructor is required before you fly cross-country or to another airport to land.  61.93(b) covers what the instructor must do with you before you can do anything specified in 61.93(a).

In the scenario that you describe you are not "Conducting a solo cross-country flight, or any flight greater than 25 nautical miles from the airport from where the flight originated" or "Making a solo flight and landing at any location other than the airport of origination" so subsection (b) does not need to be complied with at all.

The endorsement would only be needed if you were going to takeoff solo from your home airport, fly to the destination (which as you said is only 10 miles away), and land there since it is required by 61.93(a)(ii).


Why would engine fire cause loss of control?

In general, an engine fire in a modern jet airliner should not cause a loss of control.

Even though engine fires are rare, pilots are highly trained in dealing with them. Once detected, pilots are able to cutoff the supply of fuel and hydraulic fluid to the engine, and then discharge fire extinguishing agents. Even if the fire was not extinguishable, it would most likely not damage the wing structure or controls since the heat and flames would be directly away from critical systems by the forward movement of the aircraft.

An "uncontained" catastrophic engine failure where parts of the engine penetrate the aircraft wing and fuselage could possibly cause major damage to critical systems. There have been some incidents of uncontained failures that resulted in a loss of control and fatalities.

Here is a list of Notable uncontained engine failure accidents

Three of these accidents resulted in a loss of control and fatalities. The most notable was United Airlines Flight 232 where the failure of the rear General Electric CF6-6 engine caused the loss of all hydraulics forcing the pilots to attempt a landing using differential thrust and resulted in 111 fatalities.


What are the continued education requirements for commercial / airline pilots?

This question is difficult to answer comprehensively as the continuing education requirements are complex and varied. The complexity is because the continuing education requirements are mandated by multiple parties (the FAA, insurance companies, clients, and employers) and depend on the regulations the flight is conducted under (14 CFR 91, 121, 135, 137, etc.), the type of aircraft operated (single engine, multi-engine, turboprop, jet), and the pilot's role in the operation (PIC, SIC).

Note that both the Commercial and Airline Transport Pilot (ATP) license are good for life, unless revoked or surrendered. Any continuing education requirements are to retain the employment or the privileges of exercising the license, unlike CE requirements for licenses in some industries.

In very broad brush strokes, most professional pilots will be required to complete a flight proficiency check, either in an actual aircraft, or in a simulator, every 6 to 12 months. The amount of time will vary for such checks, but 3 hours might be typical. This proficiency check will be accompanied, in some cases, with a written or oral examination. In addition to this, insurance may require an aircraft systems class and simulator brush up session every 12-24 months. Such training is usually accomplished in 3-6 days, including roughly 12-24 hours of lecture/bookwork, and 6-10 hours of simulator time.

In addition to the flight and systems training, pilots employed by air carriers will generally be required to receive instruction on operational aspects of their operation, including such topics as RVSM, hazardous materials, weather, physiology, as well as many others. Such training is often self-paced, computer based training (CBT). I would estimate the time commitment for this training to be 20-40 hours annually.

In addition to the required training and testing, many pilots choose to spend additional time studying aviation related topics. Such topics may include all those alluded to above, as well as other topics. Examples of such study would be changes to company operational procedures, brushing up on checklist memorization, FAA advisory publications, and areas of interest outside of normal operations, such as international operations. Speaking personally, I probably spend roughly 10 hours a week in what could be considered aviation related study or learning. I also often see other pilots at my company studying various aircraft or operational manuals, and our company keeps a collection of articles, FAA advisories, and other publications related to our operation with the intent that pilots voluntarily study these materials as they have time. Bear in mind that a pilot's life often involves a great deal of waiting, a task which often lends itself to reading and study.


If an aircraft has two altimeters what is the allowed difference between them?

In flight, where there is no field elevation to compare to, tolerances are specified as "between the 2 altimeters." On the ground, they also must both be within 75' of the known field elevation.
Different systems may specify different in-flight tolerances, which may also vary somewhat with altitude.
See also, What is the maximum allowed difference between two altimeters for flying in RVSM airspace?


What are Uses of thin airfoil and thick airfoil?

Thick, cambered airfoils such as the Gottingen, Clarke Y and Davis are the most efficient airfoils up to speeds where Mach number becomes critical.

Lift is determined by the lift formula:

$Lift$ =  1/2 × Coefficient of Lift × Air density × Wing Area × Velocity$^2$

Coefficient of Lift can be further broken down into Angle of Attack and Airfoil type.

So a smart designer picks the most efficient airfoil and the least amount of area required
to lift a given weight.

Now time to choose.  By virtue of Bernoulli, the highest lift to drag ratios are achieved by accelerating air over the top of the wing.  This is where thick wings shine, much to the amazement of aircraft designers 100 years ago.  Thick wings also have gentle stalling characteristics, helping make the Fokker D.VII a real hit in 1918.  The thickness also enabled internal cantilever construction instead of bracing wires, paving the way for higher speeds until...

Higher airflow velocity above the wing approached trans sonic speeds, which lead to an increase in drag.  This forced designers to give up the top lift and use bottom lift, where the airflow is slower. That lead to the "supercritical" wing for high subsonic cruise.  Super critical wings feature a very "flat" upper surface.  Note airliners drasticly increase camber for slower phases of flight with retractable slats and flaps.

Supersonic aircraft wings are thin to avoid drag, but can create lift with a swept leading edge, much like a paper air plane.  This type of lift is called vortex lift.  As seen from the formula above, Velocity is squared.  This means that at high speeds, the wing need not be as efficient to generate the desired lift, as seen in designs such as the Concorde.

Of course, with very little weight, like a paper airplane, it works too.


What is this stripe on the windshield of the Embraer E-Jet?

It's a heater bus bar. In fact, the Q/A about the sensor loops that you linked has a great example of the same if you scroll to the bottom of the best answer.


Landing currency day and night on same ride?

As pilots we often talk about night flying and daytime flying meaning when it is dark or light, but for logging time and for currency in the US there are specific definitions that we must pay attention to.

  FAR 1.1 General Definitions

  Night means the time between the end of evening civil twilight and the
  beginning of morning civil twilight, as published by the American Air
  Almanac, converted to local time.

Day is not defined in the FARs but the definition of night implies that it is the time between the beginning of morning civil twilight and the end of evening civil twilight.

The Air Almanac is published annually on CD-ROM but you can find sunset, sunrise, and civil twilight times for specific locations at the US Naval Observatory website or in ForeFlight.

The time between sunrise/sunset and twilight is 26-30 minutes depending on the time of year. Since you can easily find sunrise/sunset information in newspapers, the weather channel, etc. you can estimate twilight fairly easily.

Currency

  §61.57 (b) (1) … no person may act as pilot in command of an aircraft
  carrying passengers during the period beginning 1 hour after sunset
  and ending 1 hour before sunrise, unless within the preceding 90 days
  that person has made at least three takeoffs and three landings to a
  full stop during the period beginning 1 hour after sunset and ending 1
  hour before sunrise, and…

VFR Weather Minimums
Only Class G airspace has different minimums depending on night and day and they use the standard night definition—end of evening twilight to the beginning of morning twilight.

Aircraft Lights
Aircraft lighting is required between sunset and sunrise.

  §91.209 During the period between sunset and sunrise no person may 1.
  operate an aircraft unless it has lighted position lights, 2. park or
  move an aircraft in an area of an airport where night operations are
  being conducted unless it is clearly illuminated, has position lights,
  or is in an area marked by obstruction lights.

Aeronautical Experience Requirement
In order to obtain a private pilot certificate night training is required. The commercial pilot certificate required solo night flights. In these cases the standard night definition—end of evening twilight to the beginning of morning twilight—applies.

Special VFR
AIM 4-4-6 g. Special VFR operations are prohibited between sunset and sunrise unless the pilot is instrument rated and the aircraft equipped for IFR flight.

Logging Night Flying Time
Logging of night flight should be made in accordance with Part 1 definitions, which is from the end of evening civil twilight to the start of morning civil twilight. This differs from the definition used for night currency.

Summary

• Position lights – sunset to sunrise

• Special VFR – except sunset to sunrise unless instrument rated

• Carry Passengers – 1 hour after sunset to 1 hour before sunrise

• Everything else – evening twilight to morning twilight

The answer to your question.

Now that we have that out of the way, we can look at the requirements for carrying passengers.

  §61.57   Recent flight experience: Pilot in command. (a) General
  experience. (1) Except as provided in paragraph (e) of this section,
  no person may act as a pilot in command of an aircraft carrying
  passengers or of an aircraft certificated for more than one pilot
  flight crewmember unless that person has made at least three takeoffs
  and three landings within the preceding 90 days, and—

  (i) The person acted as the sole manipulator of the flight controls;
  and

  (ii) The required takeoffs and landings were performed in an aircraft
  of the same category, class, and type (if a type rating is required),
  and, if the aircraft to be flown is an airplane with a tailwheel, the
  takeoffs and landings must have been made to a full stop in an
  airplane with a tailwheel.

  (2) For the purpose of meeting the requirements of paragraph (a)(1) of
  this section, a person may act as a pilot in command of an aircraft
  under day VFR or day IFR, provided no persons or property are carried
  on board the aircraft, other than those necessary for the conduct of
  the flight.

You can remain current for carrying passengers in the daytime by making three takeofffs and landins either with or without passengers. If you are not current, you may regain currency as long as you don’t have passengers.

A separate regulation governs night currency—where night is 1 hour after sunset until 1 hour before sunrise.

  §61.57   Recent flight experience: Pilot in command.** b) Night
  takeoff and landing experience. (1) Except as provided in paragraph
  (e) of this section, no person may act as pilot in command of an
  aircraft carrying passengers during the period beginning 1 hour after
  sunset and ending 1 hour before sunrise, unless within the preceding
  90 days that person has made at least three takeoffs and three
  landings to a full stop during the period beginning 1 hour after
  sunset and ending 1 hour before sunrise, and—

If you are night current then you have satisfied §61.57 (1) and so you are also day current.


How do anhedral and dihedral affect the efficiency of a wing?

The lateral flow effect you are talking about affects both top and bottom so would roughly cancel out. Pressure gradient induced lateral flow is outbound on bottom but inbound on top. The wing is at a fairly low angle of attack in cruise flight; even near stall AoA is only about 18-20 degrees and retains fairly normal flow up to that point.
With very large dihedral or anhedral the isolated airfoil section would produce lift just as efficiently as a flat wing but the overall aircraft is less efficient because it wastes the lift produced. At 45 degrees from level the wing would need to produce lift equal to 1.4 times the aircraft weight. Same as being in a 45 degree bank but with no turn as the wing vector forces are fighting each other. At low angles the wasted lift is not significant compared to the effect on handling and stability. At 5degrees dihedral or anhedral the lift is 1.0038 times the gross weight, or 0.38% less efficient.


Can I do an alternator check at idle in a C152?

The problem is the light might come on on its own at idle, which is normal.
The warning light comes on when the system voltage is below 12.5 volts on a 14 volt system, and 25 volts on a 28 volt system. Automotive alternators (which most Lycomimg powered light aircraft have) need to spin at at least 2000 rpm to make adequate charging current to maintain system voltage under load.
The belt drive on the engine that overdrives the alternator relative to engine rpm may or may not maintain this rpm with the engine idling, so the bus voltage of the system may be just over 12.5/25 vdc or just below it, depending on the loads on the system (like radios and lights, etc.) and the alternator's condition.
The 152's POH specifically warns you that the light may come on after extended idle periods with electrical loads on the system, so this is to be expected, and it means that a test done with the switch can't be trusted to give a valid result (the light could be on because of "normal" idle low voltage, not because you switched it off).
Doing it at runup rpm just makes sure the alternator is spinning well above this marginal operating condition so it's producing normal charging current when you switch it off.


Is there any airport planning to install ILS CAT IIIc?

Landing is one thing, taxiing with no visibility whatsoever is another.
At the moment the answer is no. But new rules are in place that may one day allow it (or its equivalent). See this Rockwell Collins post: Worth the Wait — FAA’s New EFVS Rule FAR 91.176.

Main benefits to FAA’s new EFVS rule:

Enhances low-visibility flight and ground operations

(...)

Enables descent below Decision Altitude/Decision Height (DA/DH) or Minimum Descent Altitude (MDA) in low visibilities on a greater number of approach procedure types (precision, approach procedure with vertical guidance (APV) and non-precision)

It's still a new rule and thus the implementations are not clear yet.

RE: Why have specs and not use them?
The CAT IIIc definition may soon be removed:

[A] preview of proposed changes to the draft OpSpec and 14 CFR part 121 to date [was presented]. The definition of Cat IIIa, IIIb, and IIIc will be removed from the regulation. The FAA will continue to use the same definitions, however they will not be defined in 14 CFR. In the future, expect the NOS Charts to depict only one minima for Cat III.

It's unclear what that will entail. And what ICAO will do. So there's a chance the zero/zero definition will no longer be there.

Related: Is it true an ILS CAT IIIc can automatically taxi-in an aircraft?


How to properly enter a holding pattern?

to source from wikipedia:

  There are three standard types of entries: direct, parallel, and
  offset (teardrop). The proper entry procedure is determined by the
  angle difference between the direction the aircraft flies to arrive at
  the beacon and the direction of the inbound leg of the holding
  pattern.

  A direct entry is performed exactly as it sounds: the aircraft flies directly to the holding fix, and immediately begins the first turn
  outbound.

  In a parallel entry, the aircraft flies to the holding fix, parallels the inbound course for one minute outbound, and then turns
  back, flies directly to the fix, and continues in the hold from there.

  In an offset or teardrop entry, the aircraft flies to the holding fix, turns into the protected area, flies for one minute, and then
  turns back inbound, proceeds to the fix and continues from there.

As you can see the maneuvers are all inside the area circumscribed by the holding pattern (not counting flying directly to the holding fix) so you can assume the airspace is clear at your altitude.

Important to note is that you should fly directly to the beacon and then reorient yourself as appropriate.

The airport approach charts will indicate where the beacons/landmarks are located, which code they use and which heading the "inbound" leg (when flying towards the beacon) has.


Why is the CFM56 produced with two different thrust reverse options?

Hispano-Suiza has delivered the world's first target-door reverser for a big turbofan, the A320's CFM56

The extending petal-shaped doors type is a Hispano-Suiza specialty. It's a French company and one of the three major suppliers of reverse systems.
In the 80's Hispano-Suiza had to be innovative to capture a bigger market share. Their door type was the first ever on a high bypass engine. They believed investing in R&D will help increase their sales (it did). The petal reversers also double as airbrakes.

Why not on the Boeing 737?
Since the CFM56 on the 737 is close to the ground, the doors would scrape the pavement. And—more importantly for other aircraft types—Hispano-Suiza's competitors are Rohr and Boeing. Boeing definitely would like to keep things in-house with their translating/cascading reversers.
Nowadays with the jet engines of the smallest regional jets to the wide-bodies being as wide as the fuselages, the cascading type is the better choice.

Sources:

Flight, 1986 / 1600
Flight, 1994 / 0230


Can jet engine ingest (suck in) concrete from runway?

Small, loose pieces, it sure could.  But those are small flakes which would fit in your hands.  Large chunks, it’s doubtful that the suction could lift them to ingest them off the runway.  Now there’s a chance such a piece could get kicked up by the nosewheel of an airplane during a ground roll and thrown into the intake of an engine.  Airports generally have surface crews which periodically do FOD sweeps of the runways and taxiways looking for debris like that.


Where is the regular wheel brake input on modern airliners?

The same way it is done in small airplanes and older airlines -- toe brakes.

The rudder pedals translate forward and back to actuate the rudder and they pivot around the lateral axis to actuate the brake system.  Each pedal independently controls only the brakes on its side of the airplane (e.g both pilots left toe brake actuates the brakes on the left main gear).

Planes will often have an emergency or parking brake, which will be a lever somewhere that actuates the brake system.  This system, outside of emergencies is only used when the plane is not moving and you want it to remain that way.

Larger airplanes with also sometimes have autobrakes which provide a triggered automatic application of a certain level of braking.  This kind of system is used both to provide automatic maximum braking for a rejected takeoff (RTO) and some lesser automatic braking upon landing rollout.

To summarize, for taxi and ground movement the brake input is coming from the toe brakes.  When the aircraft is stopped, brake input will be transferred from the toe brakes to the parking brake.  When the plane lands, if it is so equipped and enabled, the autobrakes will begin brake application and the pilot will take over with the toe brakes and continue to use toe brakes for the taxi in.


Will manually removing nicks from compressor blades significantly affect the operation of the compressor?

Yes, this is not only acceptable, it is required by the engine maintenance manual. The tools might be more sophisticated in other shops, but the basic concept of removing material by hand is the same.  The process is called "blending". The impact of sand or dirt on the blades causes little nicks and scratches. Those sharp or rough areas create what is known as a "stress concentration".  If left as-is, the nicks will eventually grow into cracks (metal fatigue). Smoothing out the nicks removes the stress concentration and prevents the crack from forming.  There is an impact on the performance/efficiency, but that's better than having your blades crack.  From my experience, the performance impact of what is shown in the video is actually quite small. As a rough guess I would say 0.01% - 0.1% efficiency loss. Much larger nicks can be successfully blended.

Edit:
Regarding how I came up with that efficiency number. Two thoughts:

First, The compressor shown in the video is a 10 stage compressor, and as a rough estimate, each stage probably has about 30 - 50 blades. I didn't try to count exactly but let's just call it 400 blades. It is a reasonable assumption that each blade does the same amount of work.  In reality some stages will be a little more heavily loaded than others, but it's fairly close. So if you removed 1 entire blade, as a rough order of magnitude estimate, you would expect that to be about 1/400 = 0.25% efficiency loss.  The amount of material removed is clearly much less than an entire blade, so the efficiency loss should be less than 0.25%.

Second, I have seen compressors that had much much larger nicks be blended out and have on the order of 0.1% - 1% efficiency loss.

So between the two of those ideas, I made an educated guess on the efficiency number. Could I be off by a little bit?  Absolutely. But I'm probably at least close.


My experience is with US students who have joined the US Air Force, Navy or become Army Aviators.

My non-flight study guide includes:

Critical thinking
Physics problem solving
Math problem solving
argumentation (related to critical thinking)
FAA Private Pilot and Instrument Pilot training material
where possible visits to towers, TRACON, etc.
volunteering at:  glider club, medvac company
public speaking
STEM college degree, not necessarily in aeronautical science

In college there will be more opportunities, and additional guidance.  Many high school students have learned to fly.  It's nice to have former students who are flying F-16s in various parts of the world.  Some who wanted to be fighter pilots ended up doing things like B-2s, tankers, etc.

Since most pilot jobs involve being an officer, leadership skills are important, and help differentiate applicants. You will always have to somehow differentiate yourself, to be competitive. Every former fighter pilot I know is very competitive.

Best.


Can I land a plane in a field in the UK and Republic of Ireland?

No, you can't shuttle back and forth over the border from one field to another between the UK and Republic of Ireland (RoI) because of regulations. The RoI requires you go through an airport of entry when entering and leaving the country, see the IAA AIP Gen 1.2-1:

  Aircraft landing in the territory of Ireland must first land at an
  International aerodrome or at a licensed aerodrome where customs and
  immigration facilities are available. Aircraft departing must finally
  depart from an International Aerodrome or from an aerodrome where
  customs and immigration facilities are available.

The UK has no requirement to take off and land from a customs airfield, you can go and land from anywhere (from a customs perspective), which is handy. You do have to notify Special Branch at least 12 hours ahead of your flight if you are going to and from the RoI, channel islands or Isle of Man and give them details on who is going and where you are going from and to. You must do this even if you plan to go to and from a customs airport on the UK side.

In the UK you can use a field up to 28 days a year without getting planning permission from the council, provided you own the land (or have permission from the owner) and it is safe to do so. If you plan to do more than 28 days you'd need to talk to the local council and the CAA. I don't know about the RoI though.