Buy it from Boeing.
Documents like the FCOM and the AMM are copyrighted and proprietary documents and aren't meant to be freely available.  Sometimes you'll find one on the internet that somebody posted, but they did so in violation of a license.
If you do find an AMM (or excerpts from it -- as far as I know the entire document is enormous) on the internet, changes are good that it's well out-of-date.
That said, there are better resources than the AMM to learn about the operational side of the 737.  As a pilot who flies it, the AMM isn't a document that I study or even have in the electronic flight bag.  It's for mechanics, and in some cases its limitations are significantly different than the limitations in the flight crew manuals (the company equivalent of the FCOM).  There are things that the mechanics can do on an as-needed basis that they don't want the pilots doing during routine ops, and so our limitation, for example, was in the 737-300, only one pack run off of APU bleed air for cooling.  The mechanics could run both packs for cooling, but when they did that it wasn't in order to cool the aircraft, it was to load up the APU and see how it responded to a high bleed air demand.  The first time I saw them do that was a "wait, you can't do that!" kind of moment, but their manual allows it.
Boeing, however, does NOT want pilots performing hybrid procedures, or "I saw a mechanic do this..." fixes.  Things that may work fine on the ground at the gate, may be a really bad idea to try in flight.  So Boeing has pilot procedures & limits for the pilots, maintenance procedures & limits for the mechanics, and just like in Ghostbusters, "don't cross the streams... it would be bad."


What is this part on a Cessna 172 engine?

NOTE: Revised in response to poster comment: The engine is a Lycoming O-320 D2G, part of the series that replaced the disastrous H2AD engine which that '77 172 originally came with, in 1981 (the H2AD was '77 to '80). The H2AD engines (I have to think some joker at Lycoming put the AD designation in as a gag — it had a number of ADs against it), among other problems had a very small valve lifter contact face that would spall very quickly and trash the camshaft (on the plus side, you can remove the lifters without splitting the case).  Most 77-80 172s have had their H2AD engines replaced with Ds, which went back to the old lifter design, which also applies to the airplane pictured.

Anyway, the fitting is tapping into an oil gallery that supplies the valve lifters and has a plug at each end.  Someone has removed the plug at the front and installed the elbow to run oil pressure back to a cockpit indication, possibly because the port normally used on the accessory case is being used for something else.


Why do helicopter flights not appear in online flight trackers?

FlightRadar and similar websites use several sources for aircraft detection, most commonly they use ADS-B. Not all General Aviation aircraft, to which helicopters would count normally, are equipped with transponders that are capable of emitting ADS-B data, so they would not show via regular means on FlightRadar.

The primary technology that Flightradar24 use to receive flight information is called automatic dependent surveillance-broadcast (ADS-B).
ADS-B is a relatively new technology under development which means that today it's rarely used by Air Traffic Control (ATC). Our estimations show that roughly 65% of all commercial passenger aircraft (75% in Europe, 35% in the US) are equipped with an ADS-B transponder. For general aviation this number is probably below 20%. But this percentage is steadily increasing as ADS-B will become mandatory for most aircraft in most airspaces around the world, by year 2020. When mandatory, ADS-B will replace primary radar as the primary surveillance method used by ATC.
Flightradar24 has a network of more than 4,000 ADS-B receivers around the world that receives plane and flight information from aircraft with ADS-B transponders and sends this information to our servers. Due to the high frequency used (1090 MHz) the coverage from each receiver is limited to about 250-400 km (150-250 miles) in all directions depending on location. The farther away from the receiver an aircraft is flying, the higher it must fly to be covered by the receiver. The distance limit makes it very hard to get ADS-B coverage over oceans.
About 99% of Europe is covered with ADS-B receivers. There is also good ADS-B coverage in USA, Canada, Mexico, Caribbean, Brazil, Russia, Middle East, India, Japan, Thailand, Malaysia, Indonesia, Australia and New Zealand. In other parts of the world the ADS-B coverage varies.

The other option is to receive the regular Mode-S transponder signal by a technique called Multilateration (MLAT), however the FlightRadar website states that this is something that only works reliably at high altitude, at least 5 000 to 10 000 ft.

In some regions with coverage from several FR24-receivers we also calculate positions of non-ADS-B equipped aircraft with the help of Multilateration (MLAT), by using a method known as Time Difference of Arrival (TDOA). By measuring the difference in time to receive the signal from aircraft with an older ModeS-transponder, it's possible to calculate the position of these aircraft. Four FR24-receivers or more, receiving signals from the same aircraft, are needed to make MLAT work. That means that MLAT coverage can only be achieved above about 5,000-10,000 feet as the probability that signal can be received by four or more receivers increases with increased altitude.
Most parts of Europe are today covered with MLAT above about 5,000-10,000 feet. There is also some MLAT coverage in North America, Mexico, Australia and Brazil. More areas will get MLAT coverage during 2014 and 2015.

For more information, check FlightRadar's "How it works" page.


Are civilian/GA pilots expected to "see and avoid" fast military jets in VMC?

It is both parties responsibility to see-and-avoid, but it does help to know where you are more likely to find high speed military activity and high performance maneuvering to aid you in seeing and avoiding.

Military operations in the US are typically confined to military training routes (MTR), military operations areas (MOA), restricted airspace and prohibited airspace.

The MTRs are low altitude, high speed routes and are charted on sectional charts so you know to be extra vigilant around them or to just avoid them altogether.

Military operation areas or MOAs are charted and are big boxes with ceiling and floor altitudes.  GA aircraft can query ATC if these are active and in any case they can fly into them.  If a GA aircraft penetrates and active MOA, the military activity is typically stopped until you leave.  General rule of thumb is to just not go there.

Restricted areas are only accessible to you when cold, so there will not be military activity there if you allowed to be there.

Prohibited airspace may not have military activity before you show up, but certainly will after you do, and you might get to watch an F16 attempt slow flight and form up on your wing.  Remember your intercept procedures for this one.

Any military activity outside of this will generally be typical enroute flying at altitude.  You will occasionally hear ATC coordinating mid-air refueling but that won't be something you have to worry about.


Radio communications lost on climb out in IMC: when can I turn on course?

Your assumptions are insufficient.

If your clearance just states "CLIMB 6000 direct", and there are obstacles along the route, you have been given an incorrect clearance.

It should have included the phrase "EXPECT" and an altitude and possibly also a time that would permit you to clear the obstacles.

Also, from your Skyvector link, it looks the Direct course parallels V97 very closely, which has an MEA of 5000, so you should not encounter any obstacles at 6,000.  Once you reach your clearance limit LOZ, you may initiate the approach.

Nevertheless If you lose comms you are expected to climb to the hugest altitude of 1. Your last clearance altitude 2. Minimum IFR altitude. 3. The altitude you were told to expect


What are the random, differently-coloured rectangular patches on the top of this Boeing 737's fuselage?

They aren't "repair patches" themselves, they are repainted areas where some sort inspection and/or repair was done to the underlying structure, that required removal of the paint in the area. What the inspection or repairs were done?  Well, you'd have to have been there to know, but the 737 does have a lot of structural inspection requirements related to fatigue cracking in fuselage frames and skins.
There may be actually be skin outside doubler patches riveted on in those dark spots to reinforce areas where crack repairs were done, but the borders of the dark spots are just paint masking lines and it's hard to tell in the photo what was done.
Another possibility is that surface corrosion was found at those spots and the paint in the area was stripped, the corrosion was blended out and the zone repainted.
They should probably have their paint guy do some mixing to match the fresh paint to the faded paint, and apply the paint with an edge feathering technique to avoid the sharp masking lines (you have the edges of the mask supported above the surface to allow some paint to spread below, to create a soft edge), so that folks in gate areas looking down at their incoming flights would be less alarmed by the Quilting Bee look.


Airbags in aircraft - is that just a military thing?

Airbag seatbelts on planes are a "new" thing (well, since about 2001 apparently), but they're available on new-production aircraft and can be retrofitted to older General Aviation planes as well.

You can also find them on some airliners (typically in the exit rows where the next row is too far away to assume a proper brace position).

AmSafe (the folks who make a good percentage of the aviation-approved seatbelts) has a nice video (or two) on the subject of aviation airbags.


Can a plane turn around like on this photo?

hoax, totally. that plane is travelling at about 550MPH and the forces required to turn it 180 degrees with a radius of ~two wingspans would destroy the plane and kill everybody in it.


Why do cargo airplanes fly fewer cycles then airliners?

It's due to the overnight parcel distribution model which limits the available operating time.  A parcel picked up by 5pm needs time to get a terminal, and then has to get to the destination distribution terminal in time to be distributed and dropped off by mid afternoon the next day.

This means the heavies in the freight business do their flying overnight running between their distribution hubs (being a "Freight Dog" pilot is considered a night shift sort of career with fewer hours flown per year than pax flying, maybe 300-500 hours vs 700-1000 flying pax) so that freight can arrive at distribution points in the morning where it goes out to sub terminals on smaller aircraft during the day, or sent out by truck.

For example, Fedex runs aircraft in and out of Atlanta only between 10pm and 6am.  For many years I worked at an airport with a Fedex Terminal and you would wonder how anything got done because all you ever saw during the day was parked MD-11s lined up in front of the terminal, apparently just sitting there, with no freight movements to speak of after about 7 am, except for smaller a/c flying sub-distribution runs through the morning.  Well they are actually just waiting for their outgoing freight to arrive and if you happened by at midnight, it was pretty busy and there was a fair number of a/c coming and going.

So a freighter has maybe an 8 hour operating day, whereas a passenger a/c gets flogged like a mule and starts flying at 6 am and runs until 9 pm.  Plus the loading and unloading process for pallets is somewhat slower than with self-propelled human cattle getting on and off for you.  So you can't really do more than a couple of legs per day.

To provide context, this UPS fact sheet shows a fleet of 255 UPS jets doing 318 daily trips on average

It says "In-Out" trips for that 318 number, so lets assume that's actually 2 legs, 1 in and 1 out, for 636 actual flight cycles.  That's only 2.4 cycles per day overall, almost as easy a life for the airplane as corporate.


What is the RNP requirement within the KZAK FIR?

To be exact RNAV 10 is required when operating in the KZAK FIR. This enables 50NM longitudinal and lateral separation between aircrafts.

Unfortunately, the requirement might be designated RNP 10 due to legacy reasons. The difference between RNAV and RNP is that RNAV requires no onboard performance monitoring and alerting capability, while, among other things, RNP does.

RNP 4 is optional to allow closer 30NM longitudinal and lateral separation between RNP 4 capable/authorized aircraft thus increasing the airspace capacity.

Sources:

ICAO Doc 9613 - Performance-based Navigation (PBN) Manual
ICAO Doc 8168 - Procedures for Air Navigation Services — Aircraft Operations, Volume I (PANS-OPS Vol I)


Which current commercial flights have the highest ETOPS ranking?

Air New Zealand's Auckland (AKL) to Buenos Aires (EZE) is the longest ETOPS flight I know of, under ETOPS 330. It started in 2015:

  Air New Zealand completed the first flight approved for 330-minute extended twin-engine operations (ETOPS), flying a 777-200ER powered by Rolls-Royce Trent 800 engines. The December 1 flight departed from Auckland, New Zealand, and landed in the Argentinian capital Buenos Aires about 12 hours later.

As for ETOPS 370, I'm not aware of eny regular commercial flights, but some candidates are Sydney-Johannesburg and Sydney-Santiago de Chile


What is the meaning of AFT in airworthiness directives?

The average flight time (AFT) is defined as flight hours (FH) divided by flight cycles (FC) accumulated by an individual airplane since the airplane's first flight, specified in hours and hundredths of an hour.


Is it normal for a Boeing 757 engine to bounce under its fairing?

Yes, it's normal. You will see engines bounce, yaw and shake, sometimes with apparently alarming ferocity, and you might wonder whether something is going to shake itself apart.

However, the fact is that the engines bounce because they can. Their mountings - which are extremely strong - are absorbing a lot of movement and energy safely. For example, they have to be able to handle the immense thrust that the engine puts out for the whole flight.

Another thing that you need to bear in mind is that many visible parts are themselves more flexibly attached to hidden and more stiffly mounted ones that are attached to each other. So you're not just seeing movement of structural parts, but that, plus the movement of the lighter, flexible coverings.

In short, there is nothing there to worry about, though it can be unsettling to see.


What does "storing an aircraft" technically mean?

Here there are some nice considerations.
You can basically divide stored aircrafts in two main categories: short-term and long-term.

From the link, for long-term:

  When discussing parked or stored aircraft, it is safe to assume one is referring to an aircraft that is no longer in operation and has been placed by the owner, airline or lessor into a manufacturer-approved storage regime to preserve maintenance and asset value.

Instead, for short-term:

  However, some will also refer to stored aircraft as those that are between owners. [...] a transition [...] takes time and [...] As such, an aircraft will often be stored and out of revenue service for six to 12 weeks.

or

  Additional or unusually lengthy checks can delay the aircraft from revenue service for many months, during which time they are sometimes referred to as parked or stored.

but in the end, to answer why they are not sold:

  With the exception of these transitions, the majority of aircraft in storage are there because they are no longer economically viable to operate; it is cheaper to put the aircraft into a storage programme than to fly it.

You keep it safe so that you can scrap it.


Why aren't there any widebody propliners for the high-density short-haul markets?

Not enough thrust (i.e., too many engines)

Taking the lightest wide-body, the Airbus A310-200, its MTOW (max takeoff weight) of 144-164 tonnes is >2 times that of a Boeing 737NG at 65-85 tonnes. A 737 equivalent in MTOW in the prop world is the C-130 at 70 tonnes, and it needs 4 propellers.

So we are looking at 8 propellers for an A310-sized wide-body, or 4 contra-rotating propellers, already 6 too many either way for the airlines.

A comment claims that a turboprop engine can be designed as big as needed, what's missing is that the bigger the torque, the more blades are needed, which will essentially turn a prop into a fan. A relevant post is, 'How does a fan differ from a propeller?', where Peter Kämpf compares the disc loading of propellers and fans.

Propellers on a C-130 Hercules: 259.25 kW/m²
Turbofans on a small BAe 146: 4254.35 kW/m²

Propellers driven by piston engines are the most efficient, followed by turboprops, but they don't have the thrust of jet engines. Try and picture how many propellers would be needed to lift a Boeing 747. In the commuter/regional range of 100 passengers, turboprops have great efficiency, but go bigger, and fewer engines win.

On paper all is possible, the issue is making a civilian product that makes sense, in this case, number of engines. (Airlines care about the bottom line, the military not so.)

More parts is higher maintenance cost. For turboprops some figures are in this AOPA table from Oct 2016 (variable cost that incl. maintenance):

4-pax single-turboprop is \$535.84 per hour (Piper M600)
9-pax single-turboprop is \$508.73 per hour (Cessna 208 Caravan)
8-pax twin-turboprop is \$1,194.69 per hour (Beechcraft King Air 350i)

So capacity has little impact on the variable cost, unlike the number of engines.

Fuel economy (bomber vs. airliner)

Let's call the number of engines/propellers/parts, "A", and fuel economy, "B". For the airlines, "A" tips the balance when the number of engines exceed 2, i.e., that is why civilian turboprops are of the regional size.

Comparing 4x extreme-end turboprop engines with contra-rotating propellers (8 propellers in total like on the An-22 that's been suggested in a comment), with say 2x GE CF6 jet engines (like on the lightest wide-body airliner), when it comes to only "B", is a different question that requires context:

The reason why the Bear is turboprop powered (same engine as the aforementioned An-22), is because it's a long-range bomber with loitering in mind, not a short-range wide-body airliner as asked. Turboprops were also considered for the B-52.

Addressing other comments:

The A400M was suggested as a plane that makes it possible, it doesn't. Its MTOW minus OEW minus Fuel is 15 tonnes, or 115 pax + luggage and no cargo. Also note it's only 4 m wide internally, narrower than the narrowest wide-body, the 767 at 4.72 m. This is confirmed by its max troop capacity of 116, design-wise because most of its length is to accommodate a ramp.

Ignoring all that, it's still got 2 engines that the airlines can do without.

  cargo compartment: width 4.00 m x height 3.85 m x length 17.71 m

(wikimedia.org)

A comment saying the C-130 is already wide, it is not. It's only 3.02 m wide on the inside. A 737 by comparison is 3.54 m. And wide-bodies start at 4.72 m, which allows a twin-aisle (2+3+2) configuration, one more seat than the 6 abreast single-aisle 737.

Build it lighter (composites): In the history of airliners, whenever progress was made toward lighter materials, wings are built bigger for more efficiency, and so is the cabin, because the airlines want more passengers for the same MTOW, otherwise they can't stay afloat. A prime example is the 787, it uses lighter materials, and ended up heavier than the plane it replaced, because its efficiency comes in part from the bigger wings.

Regarding the noise, military turboprops (and jets) are very noisy, but when it comes to passenger transports, turboprops match the jets. This research for example compared the noise level in the cockpits (one of the loudest parts of a plane) of similar-sized planes (A319 and Dash 8), and the turboprop was the quietest.


Do the F-18's leading edge flaps deflect symmetrically in rolls?

Quoting the F/A-18A,B,C,D Flight Manual A1-F18AC-NFM-000, I-2-42

  2.8.2.8 Control Augmentation System (CAS) [...] The lateral control system uses ailerons, differential
  trailing edge flaps, differential leading
  edge flaps, differential stabilator, and rudders to
  achieve the desired roll characteristics. Scheduled
  air data roll rate feedback is used to augment
  inherent airframe roll damping. At high
  airspeeds, aileron travel versus stick movement
  is reduced and the ailerons do not deflect above
  600 knots. Differential stabilator and differential
  trailing edge flap travel is reduced at high speed
  to prevent exceeding structural limits. The leading
  edge flaps deflect differentially up to ± 3°
  when below 30,000 feet and above 0.7 MACH. Differential flaps are not used in the takeoff or land modes nor above 10° AOA in the auto flaps
  up mode. At low airspeeds, aileron and differential
  stabilator travel are reduced with increasing
  AOA to minimize adverse yaw.

In short: Yes the F18 uses differential (asymmetric) deflections on the leading edge flaps and trailing edge flaps but the scheduling depends on angle of attack, airspeed and Mach number.


Why do many light aircraft have a trim tab on one side of the elevator only?

A small propeller driven plane like that will have a bit of adverse yaw, rolling to the left, because of propeller effects (P-Factor, slipstream, torque, etc)

The trim tab's effect is minimal because it is very small and is close to the centerline of the plane.  Any drag it creates causes a slight roll and yaw to the right, specifically to counteract the propeller effects.

That keeps the overall effect almost un-detectable.


Why does the Boeing 737 have a pitot tube on the tail?

There are five sets of pitot tubes on the 737, organized into two groups, the pitot tubes on the nose are used for airspeed measurements, independent for the pilot and copilot and one as a backup. There are two pitot tubes on the tail that are for the "elevator feel and centering unit" (pdf; page 8).

  The elevator feel computer provides simulated aerodynamic forces using airspeed (from the elevator pitot system) and stabilizer position. Feel is transmitted to the control columns by the elevator feel and centering unit.

The airspeed may not be the same due to shielding in high angle-of-attack situations. I do not believe that the airspeed from the pitot tubes in the tail is visible (or useful) to the pilots. There is a warning that appears in the cockpit when the sensor fails.


What is it called when you roll without yawing or pitching?

In the aerobatic community we would call that the beginning of an Aileron Roll.

It's harder than it looks.


Why don't helicopters prefer shorter rotors with more blades?

The rotor works by accelerating air downwards, therefore creating an upward reaction force on the blades that lifts the craft.

The lift force is equal to

$$L = \dot{m}\Delta v$$

where $\dot{m}$ is mass flow rate through the rotor and $\Delta v$ is the change of speed of the air. To accelerate the air to that speed, it has to give it kinetic energy. This requires power

$$D = \frac12\dot{m}\Delta v^2$$

(the induced drag).

Now a rotor with smaller diameter will be able to affect less air, so the $\dot{m}$ will be lower. To produce the same lift, it will need larger $\Delta v$ and therefore it will need more powerful engine (up to a point, because longer blades will have higher form drag that will eventually outweigh the reduction in induced drag) and, more importantly, burn more fuel.

The blades, like wings, affect air to a significant distance above and below them, so you don't need many blades to use all air within the rotor area. But no matter how many blades you add, they will still only affect the air within the rotor area, so the efficiency won't change much.

As far as tiltrotors go, they have relatively small rotors and that makes them awfully inefficient in hover. But they don't spend most of their time hovering, they spend most time flying somewhere and in the fixed-wing mode they are faster and more efficient, which outweighs the worse efficiency during take-off and landing.

See also: Is there any equation to bind velocity, thrust and power? (via Energizer777's deleted answer).


Can you be a commercial pilot if you have a criminal record?

British Airways has this to say:

  If you have been cautioned, warned or convicted of a criminal offence (other than parking offences) we suggest you check whether you will be able to obtain an airside pass by visiting www.dft.gov.uk.

  In order to be employed as a pilot with British Airways you will be required to undergo a Criminal Record Check for every country in which you have been a resident, or worked in, for 6 months or more in the past 3 years.

Admittedly, the DFT's website is a maze of information, and it seems very difficult to find any information; I'd suggest giving them a call, to find out for your particular convictions.

Airside Manager has some more detailed information on airside passes, in general.


Could an airliner get better fuel efficiency at higher altitude?

There are several factors to take into account to explain your question, but it is a nice one.

In a cruise flight the aircraft force balance determines that the lift compensates the weight of the air plane and the engine thrust compensates the drag.

So, assuming the weight is given (which varies along the flight) the lift is determined to ensure the air plane is not falling. The lift influences the drag, the more the lift the more drag (actually a lineal variation with the variation of the square of the lift). And so, the engine compensates the drag.

So... engine thrust depends on the weight, essentially to the aerodynamic efficiency. So, my first answer, the more efficient the aerodynamic of the air plane, the higher it can fly. So, the engine is not the only factor.

However, you are highlighting an important point, the performance of gas turbine based propulsion. The problem of this propulsion is the need for an external oxidant. Essentially, the engine needs the oxygen of the atmosphere to be able to work. So that limitation requiring oxygen will make it impossible to reach much higher flight levels.

Another option is to change the propulsion concept and use an independent engine where not only fuel is carried but also oxidant is carried in the plane. The normal answer to that one is using a rocket engine. For example, the Bell-X (first manned A/C to flight faster than speed of sound) was having a ceiling of +90000 feet using rocket propulsion.


Being an Air Traffic Controller does not provide any legal shortcuts for piloting courses, in any jurisdiction as far as I am aware. Sure, you could probably sleep through the lectures on meteorology and maybe parts of others, but you still need to sit and pass all 14 exams. You would have little to no advantage on the subjects of aerodynamics, aircraft systems, performance and loading, and human factors.
You also need to complete the practical flight training and meet the same requirements as everyone else.


Are there any heavy lift jets (like Stargazer) with zoom climb (like Ye-66A MIG-21)?

Zoom climb of the carrier is useless. The rocket can do it alone after release with the same effect and is slightly more aerodynamic as it does not have the large wings of the carrier.

The rocket starts with certain amount of energy upon release. Part of this energy is kinetic, given by speed of the carrier, and part of this energy is potential, given by altitude. Now a zoom climb means exchanging kinetic energy from going fast for potential energy to climb higher. But the total amount of energy does not change. And since the rocket still needs to increase both it's kinetic and it's potential energy (accelerate and climb) it does not really care which form of energy it gets.

Now the orbital vehicle needs energy corresponding to 7.9 km/s and a launch aircraft like the Stargazer can give it perhaps 0.57 km/s (of which only ~0.24 km/s will be speed, the rest is the ~12 km altitude). This is a tiny fraction of what it needs, but:

It helps significantly that the rocket does not have to penetrate the thick low atmosphere. At 12 km the pressure is 19% of what it is at sea level. Going higher is not going to help all that much.
Due to the rocket equation (the amount of fuel needed is exponential) it can still make significant difference to payload fraction.

What we are likely to see is carriers that can give the orbital vehicle more initial energy. By going faster (like the F-15), by going higher (like the Stratolaunch) or both (using scramjets it to gain some higher hypersonic speed at altitude perhaps 30 km). But they won't do zoom climb, because that does not add any energy and adds complication.


Why on weather surface charts high pressure is blue and low pressure is red?

Red/blue for pressure is in no relation to surface temperature. Storms develop where the pressure is very low. Red being associated with danger is a good color choice for low pressure.

  Storms are created when a center of low pressure develops with a system of high pressure surrounding it.

Low pressure is also associated with decreased aircraft performance, both lift and engine power. See below and find the strongest storm system.

(Source)

Blue for cold and red for hot is used for coloring the weather fronts:

(Source) 1. cold front 2. warm front 3. stationary front.


How does radar receive Mode C information?

Correct.  Mode C responses include the pressure altitude.  This means that many installations use a separate altitude encoder that has no barometric settings.

Whether it is integrated or a separate unit, the kollsman setting does not change the pressure altitude reported.

From http://www.faraim.org/aim/aim-4-03-14-133.html

  Mode C Veil. [...]  Unless otherwise authorized by ATC, aircraft
  operating within this airspace must be equipped with automatic pressure
  altitude reporting equipment having Mode C capability.


MOCAs provide minimum obstacle clearance, as you note; MEAs also provide this—and more.

MOCAs are determined essentially the same across the board. The question that I think you should ask is why is the MEA higher than the MOCA in some cases where you might not expect it, namely in the case of some GNSS MEAs.

Firstly, all MEAs take into account multiple factors, including those described in the following. Note the mention of airspace buffers and communications requirements.

From the FAA's Instrument Procedures Handbook, on p. 2-35:

  The MEA is the lowest published altitude between radio
  fixes that assures acceptable navigational signal coverage
  and meets obstacle clearance requirements between those
  fixes. The MEA prescribed for a Federal airway or segment,
  RNAV low or high route, or other direct route applies to the
  entire width of the airway, segment, or route between the
  radio fixes defining the airway, segment, or route. MEAs
  for routes wholly contained within controlled airspace
  normally provide a buffer above the floor of controlled
  airspace consisting of at least 300 feet within transition
  areas and 500 feet within control areas. MEAs are established
  based upon obstacle clearance over terrain and manmade
  objects, adequacy of navigation facility performance, and
  communications requirements.

Earlier, on p. 2-16, the requirement for communications reception in the case of GNSS MEAs (at least those on RNAV T-routes) is explicitly stated. This makes sense given that these two factors are the primary factors needed in flight guided by GNSS.

  A GNSS MEA for each segment is established to ensure obstacle
  clearance and communications reception.

I'm not sure that this answers your stated questions, but I do think it should ultimately answer what you are wondering.


Why do the old A320s have a lower tailwind limitation compared to the newer enhanced ones?

Short answer: the increase from 10 to 15 knots requires extra certification / flight testing, which is an extra item the airline will pay for.

Over at pprune:

  Boeing offers an increased tailwind limit of up to 15 knots for a fee.

I suspected that but had no proof, so that got the ball rolling.

From page 35 of an Airbus presentation presented to the civil aviation authority of PRC confirmed that being an option:

  Other configurations outside China include options as:

  Water/waste freezing protection for extended flight conditions
  15 knots tailwind certification at landing
  15 knots tailwind certification at take off

And finally from the FAA's Flight Test Guide For Certification Of Transport Category Airplanes, there is a section for certifying takeoff and landing in tailwind greater than 10 knots.

It requires the demonstration of controllability, engine performance, autoflight systems, landing gear vibration, terrain awareness warning systems to not be affected by the higher sink-rank, etc.

Note that for a takeoff in tailwind >10 knots, even the application of takeoff thrust is different from when <10 knots. The advisory circular also calls for a disclaimer of sorts to be added in the AFM:

  The AFM should contain a statement that the limitation for tailwinds greater than 10 knots reflects the capability of the airplane as evaluated in terms of airworthiness but does not constitute approval for operation in tailwinds exceeding 10 knots.

Of course if the airline would also pay even more for the brake cooling fans option, they can reduce the longer cool down period after a tailwind landing, for example.

Some performance enhancements require extra certification and testing, but not necessarily extra equipment.

An airline can request their fleet to be certified for a lighter or higher MTOW depending on their operation. A light MTOW on the certification is cheaper to obtain, and it will allow the airline to save on ramp fees, route charges, etc. But on the other hand they can't carry as much payload/fuel. Other high MTOW options may require extra strengthening built into the airframe and more powerful engines.


In a part 91 formation flight within a mode C veil, are all the aircraft required to have their transponders on?

The way 91.215 is written, you must operate your mode C transponder in rule airspace unless ATC tells you not to.

The reason ATC tells you not to squawk in the case of a formation flight is to avoid triggering a constant stream of Collision Alerts between members of the formation, which is useless, annoying and may distract them from an actual problem elsewhere.

However, the CA is suppressed if all the aircraft involved are squawking 1200 (VFR) because there's no point warning the controller about a possible collision between multiple aircraft they're not talking to.


The biggest single reason for the decline of flying boats was the proliferation of long runways during World War II. The infrastructure advantage of flying boats – the ability to operate heavy aircraft without long runways – was no longer relevant. Large airfields were a result of the long-range heavy bomber campaigns in Europe and Asia.

Century of Flight has an interesting article that goes a bit more in depth.


Is there a name for change in attitude with respect to time?

The components of attitude vector are called:

yaw (or heading) is the angle of longitudinal (x) axis in horizontal plane,
pitch is angle of longitudinal (x) axis from the horizontal and
roll is angle of lateral (y) axis from the intersection of the yz (orthogonal to longitudinal axis) plane with horizontal.

And their derivatives are usually yaw-rate, pitch-rate and roll-rate. Second derivative names probably vary.

Regarding coordinate system, the first axis, called x, is always longitudinal and positive direction is forward. The second axis, called y, is usually lateral one, but positive direction is right in some systems and left in others. And z completes a right-handed coordinate system (so your vector products work the usual way), so z down if y points right.

Edit: I thought u,v,w is sometimes used as alias for the axis, but actually they are usually rather used for the velocity vector components.


What advice would you give a novice pilot on controlling the rudder?

It's very normal for most students to struggle with the rudder initially.

One aspect that got me while learning to fly:

Unlike stick inputs is not 'applied pressure' that measures the effect of the rudder, but the actual physical displacement of the pedal. It was quite usual for me to feel the need for right rudder, increase pressure on the pedal but with very little actual pedal movement, so there was practically no effect on the a/c.

So I made a conscious effort when right rudder was needed to apply pressure enough To Move The Pedal.

In other words if you want to double the effect of the rudder you need to double the pedal displacement, not double the pressure applied.

Second thing that got me to using the rudder correctly:

Make a mental note to use rudder

when using the ailerons
when changing power settings.

Pretty soon these actions will become linked by the brain and you will do it unconsciously. Then with time you will also learn to use the correct amount.

On feet stance

I am pretty short at 1.70m so I was usually selecting the closest setting for rudder which was placing the rudders very close to my knees, and as such it was difficult to properly use them (as my body was literally resting on the pedals). I was once advised to push them further back and it has made a world of difference: adjust them so that maximum deflection requires just a little bit of hip effort and almost a straight knee. Try a couple of positions and see which one works best; your instructor can help to show you the proper adjustment, and it does make a word of difference.


This is not implemented anywhere in the world.

Wikipedia:

  As of 2012 this category is not yet in operation anywhere in the world
  as it requires guidance to taxi in zero visibility as well. Category
  IIIc is not mentioned in EU-OPS.

Airliners:

  As far as I know NO airport in the world currently offers catIIIc as
  it has the most ridiculous minima both in the horizontal and vertical
  plane ...


What are the different variants of ILS intrumentation?

In the Boeing next-generation "NG" flight decks, the PFD can be configured one of two ways. The first way, is the default presentation, where you only see to top of the HSI. The pilot will fly the aircraft via the pips along the bottom and right of the attitude indication (and usually with the flight director cross as well):

If my memory is correct, Boeing, NASA, and others did a number of human factors studies over the years and found that this layout allowed pilots to more quickly understand critical flight information, and this layout is now standard even in GA glass cockpits (e.g. Garmin G1000, Collins Proline).

The second configuration provides a virtual "six-pack":

This configuration is primarily used for airlines that are transitioning between "Classic" and "NG" flight decks. One airline I remember in particular is Southwest, as they had a combination of 737-300/400 and -700/800 aircraft and having a classic configuration on their new flight decks allowed all of their pilots to fly any of the aircraft, without needing significant differences training. The particular presentation can be customized per the airline's needs. An airline will typically move exclusively to the modern PFD display once all of the older aircraft are moved out of the fleet.


Does a 100 Hour Inspection Start Over Every Annual?

The annual will reset the 100 hours.

See 91.409

  (b) Except as provided in paragraph (c) of this section, no person may operate an aircraft carrying any person (other than a crewmember) for hire, and no person may give flight instruction for hire in an aircraft which that person provides, unless within the preceding 100 hours of time in service the aircraft has received an annual or 100-hour inspection and been approved for return to service in accordance with part 43 of this chapter or has received an inspection for the issuance of an airworthiness certificate in accordance with part 21 of this chapter. The 100-hour limitation may be exceeded by not more than 10 hours while en route to reach a place where the inspection can be done. The excess time used to reach a place where the inspection can be done must be included in computing the next 100 hours of time in service.


How can the landing gear of an A320 be lowered in the event of a simultaneous hydraulic and electrical failure?

The A320 has an emergency gear extension handle to deploy the landing gear by gravity in case of electrical, hydraulic, or mechanical failure. To force the landing gear to extend, one of the crew must pull the emergency gear extension handle up, then turn it clockwise three turns. The cutoff valve then shuts down hydraulics to the landing gear system and depressurizes it. This allows the landing gear to fall free to the down lock position by gravity.

Source: a320dp.com


Why are there 4 hands on the throttles of this B17 during takeoff?

If you look at the throttle quadrant without all the hands involved, you can see more detail:

Source

At the bottom, the 4 levers control the pitch of the propeller blades. The FE is holding them to ensure that they are at full pitch for the entire take-off run.

The large levers in the middle are the throttles which (partly) control the manifold pressure (and power) that the engines are producing. Two pilots have hands on the throttles to ensure that all 4 engines are producing full take-off power.

But there are 4 more levers that nobody has their hands on, which control the waste gates for the turbocharged engines. These open or close the waste gates, and allow the turbo to make power. There are another 4 levers on older consoles that control the mixture settings. The levers shown above may be the mixture levers, its difficult to tell from this picture because it looks like the quadrant has been upgraded.

If you want to see a good video on how all these levers work, here is a really good YouTube video describing how to fly a B-17, start from about the 2:30 second mark, but its an interesting watch.


Why do many aircraft have both all-moving tailplanes and elevators?

Moving each part has different effect on drag:

Moving just the elevator increases camber, producing large force which is useful for manoeuvring, but it also produces more drag.

Moving the whole stabilizer, keeping the camber low, produces less drag for the same force, which is good for cruise efficiency.

That's why the elevator is used for control and the forward part of the stabilizer for trim.

The arrangement adds complexity, but it also adds redundancy. If one of the actuator breaks and jams, the aircraft is still controllable using the other part enough to make a safe landing.


What is the difference between RAIL and SFL lights?

SFL start at the decision bar. RAILs may not.  The key differentiating factor is that RAILs extend beyond the centerline lights.


Given your request to "answer with less smart words," it's hard to know what knowledge can be assumed, but I'll give it a try.

Let's say you're hand-flying the airplane straight and level, and you find that the right wing keeps wanting to drop, which you prevent by using left-aileron pressure on the control yoke. You can "trim out" the need for that left aileron pressure by rotating the aileron trim to the left (counter-clockwise).

Aileron trim is not often used for the simple reason that in normal aircraft operation, it's usually set where it should be from the previous flight.  In other words, you don't fuss with it unless you notice a need to fuss with it. In 12 years on 727s and 747s, I think I used aileron trim less than a dozen times.

The reasons that I can think of offhand that would make you want to fuss with it include:

The trim wheel was inadvertently moved (or deliberately as a bit of a prank) by someone.
A fuel imbalance has occurred between the fuel in the left and right wings.
You're doing a 3-engine ferry on the 747 or continuing a flight after having lost an engine.

To the best of my knowledge, all Boeing aircraft have aileron trim capability, not just some. Indeed, I would be surprised to find any transport category aircraft that does not have aileron trim capability.

Essentially, aileron trim can be used to to keep and airplane from responding to a situation where one side of an airplane is significantly heavier than the other side.


Which flap is better suited? Split or Plain?

As usual, the answer is: It depends.

A short comparison would read like this:

Plain flaps have better L/D when deployed at small deflection angles.
Split flaps have a higher maximum lift at the same deflection angle.

Therefore, a plain flap can be used for take-off or slow flight, as well. Split flaps are only good for landing, but in this they are better than plain flaps because the increased drag makes the landing easier.

Airflow on the bottom of the airfoil is very similar, and on the top the plain flap will exhibit flow separation somewhere along the flap chord while the split flap has a well defined separation point at the trailing edge. This should produce a more steady wake and more linear characteristics of the split flap when compared to a plain flap.

Proof: Figure 7 from Chapter 5 of Sighard Hoerner's "Fluid Dynamic Lift":


Why are airports in Greece blurred and low res in Google Maps?

The short answer seems to be that some countries have persuaded Google to blur out specific areas for "national security" reasons. Wikipedia has an article on it with some more (limited!) information. Interestingly, I couldn't find any official Google article on blurring in Maps, apart from some general references to Street View. And, as it turns out, Street View at ATH works as normal.

FWIW, it seems that Greece didn't persuade Microsoft to play along, because Bing Maps has much better images. That strongly suggests that the blurring is mostly security theater.

(By the way, I'm not saying that there are no security/privacy risks with Google Maps, Bing or other tools; it's just that some risks are more credible than others. security.SE would be a good place to ask more about that.)


What is the procedure for an engine fire in the 737-800?

In general, you always follow the steps in the Quick Reference Handbook (QRH) after any failure or other problem. An engine fire is serious enough that it requires Memory Items, which are performed immediately before getting the QRH. In this case, the memory items are the first 5 steps of the QRH checklist:

ENGINE FIRE or Engine Severe Damage or Separation

Autothrottle (if engaged) . . . . . . . . . . .Disengage
Thrust lever (affected engine) . . . . . . . . Confirm . . . . . Close
Engine start lever (affected engine) . . . . . . . . Confirm . . . CUTOFF
Engine fire switch (affected engine) . . . . . . . . Confirm . . . . . . Pull
To manually unlock the engine fire switch, press
the override and pull.
If the engine fire switch or ENG OVERHEAT light
stays illuminated:
Engine fire switch . . . . . Rotate to the stop and
hold for 1 second
If after 30 seconds the engine fire switch or ENG
OVERHEAT light stays illuminated:
Engine fire switch. . . . . . . .Rotate to the
other stop and
hold for 1 second
If high airframe vibration occurs and continues
after the engine is shut down:
Without delay, reduce airspeed and descend to
a safe altitude which results in an acceptable
vibration level.
If high vibration returns and further airspeed
reduction and descent are not practicable,
increasing airspeed may reduce vibration.
ISOLATION VALVE switch . . . . . . . . . . . . CLOSE
PACK switch (affected side) . . . . . . . . . . . . . OFF
This causes the operating pack to regulate to
high flow in flight with the flaps up.
APU BLEED air switch . . . . . . . . . . . . . . . . . OFF
Choose one:

APU is available for start:
APU . . . . . . . . . . . . . . . . . . . . . . START
When APU is running:
APU GEN switch (affected side) . . . . . . . . . . . . . ON
APU is not available:
Go to step 11

Balance fuel as needed.
Transponder mode selector . . . . . . . . . . TA ONLY
This prevents climb commands which can
exceed single engine performance capability.
If wing anti–ice is needed:
ISOLATION VALVE switch (after fire has been extinguished). . . . . . AUTO
Plan to land at the nearest suitable airport.

(Boeing 737NG QRH 8.2)
You can see that the items 2 to 4 have a Confirm written before the actual action. This means that the Pilot Flying (PF) will put their hand on the respective lever, then the Pilot Monitoring (PM) confirms that this is indeed the correct one for the engine that has a fire and says "Confirm" and only then the PF will actually perform the action. This is to make sure that you don't accidentally shut down the operating engine. After step 5, the engine with the fire indication is shut off and the fire should be extinguished.
After performing the memory items, the PM would get the QRH out and the pilots will work through the checklist (including verifying that steps 1-5 have been performed correctly).
The steps do not depend on the situation (climb, cruise or approach). You always follow the above procedure. The general order of importance is Aviate, Navigate, Communicate: first you keep the aircraft flying, then you figure out where you are going and where you want to go, then you communicate with ATC.

What should the pilot do in the cabin in these three situations?

I'm not sure what you mean by this. The pilots are in the cockpit and after figuring out what to do next, they will communicate with the cabin crew and the captain will probably make a PA to the passengers.
If you refer to pilots flying as passengers in the cabin: They would probably do nothing. A single engine fire is trained regularly by the flight crew and the two pilots in the cockpit should have no trouble handling the situation without help of a third pilot.

And at the climb stage, should the plane return to the airport of origin or continue the flight?

You can see in the checklist that step 14 says: "land at the nearest suitable airport". This is not as strict as "land as soon as possible", where you should get the aircraft on the ground without any delay (smaller airport, military airport, whatever). The nearest suitable airport should be a civilian airport within normal descent range where a landing can be performed without further risk. In the initial climb stage, this would typically be the departure airport.
Continuing the flight to the destination should only be done when the aircraft is already close to the destination anyway (e.g. during descent). An engine fire during cruise may require diverting to a different suitable airport.


Autothrottle's control target during autoland

The auto-throttle system of a typical airliner (like e.g. the Boeing 737) will maintain the approach speed (usually $ v_\mathrm{ref} + 5 \, \mathrm{kt} $, depends on the wind) during final approach. It should not reduce thrust before starting the flare because the speed could decrease too much, which could in the worst case result in a stall.
The Boeing 737 FCOM (v2 4.20.19 Automatic Flight - System Description, see also this answer for a full description of the autoland) says:

The A/P flare maneuver starts at approximately 50 feet RA and is completed at touchdown. [...]
The A/T begins retarding thrust at approximately 27 feet RA so as to reach idle at touchdown. A/T FMA annunciates RETARD.

So during the flare the thrust is decreased such that the thrust levers are closed at touchdown. This (together with the increase in pitch) will start to reduce airspeed. Ideally, the aircraft then touches down at or about reference speed $ v_\mathrm{ref} $. The thrust reduction should be smooth because the thrust-pitch-coupling of engines mounted under the wing will cause a pitch down moment, which needs to be counteracted with control inputs.


How exactly do ICAO's VOR-based minimum separation standards work?

Exactly. As long as the aircraft are diverging (i.e. flying away from the VOR), one of the aircraft is at least 15nm away from the VOR and both are at least 15 degrees (radials) apart, the separation is achieved.
You cannot use VOR separation with less than 15nm distance. The other option that can be used is "geographical separation", ref ICAO Doc 4444 5.4.1.2.1.1.
As they are still more than 15 nm away from the VOR, I would say yes. There would need to be however a certain restriction in place for the inbound aircraft to cross 15 DME (or preferably much before to have some margin) at FL50/5000ft or below, to ensure separation.
Yes. As far as one aircraft is 15nm or more away from the VOR, the separation is ensured. The photo in your question nicely depicts this, as it shows that only one (the furthest) aircraft has to be 15nm or more away from the VOR.
Yes, but you would have to ensure that they are vertically separated before the last inbound aircraft reaches 15nm from the VOR.


What happens if I activate VFR flight plan later than filed ETD?

Assuming that you've submitted a Delay Message in order to prevent your flightplan from being deleted you have to do nothing at all.

In your flightplan you only state your ETD (Expected Time of Departure) and ETE (Estimated Time Enroute). Your ETA (Estimated Time of Arrival) will be calculated and relayed to all stations in need of the ETA by AIS (Aeronautical Information Service).

To pick up your example:

Filed ETD: 1500
Filed ETE: 0200

AIS will relay ETA 1500+0200=1700 to your aerodrome of destination.

Let's say you've departed at 1554. Your aerodrome of departure will pass a departure message to AIS (so they know you are on your way) together with your ATD (actual time of departure) which would be 1554 in the example.

AIS will then calculate ATD+ETE => 1554+0200=1754 and relay the corrected ETA to your aerodrome of destination where the data in your flightstrip gets corrected.


Are afterburners required to be engaged during catapult launch?

The short answer is very much "no" -- afterburners are not at all required to launch from an aircraft carrier.  Longer answer: Fred Larson's comment is correct: it really depends.  Ultimately a given aircraft, at a given weight, with a given wind-over-the-deck, and a few other things, requires a given amount of thrust to get airborne -- whether it comes from dry thrust or afterburner doesn't change the requirement.

There are a large number of carrier-based aircraft (the A-7, A-6, and E-2 leap immediately to mind) and there are certainly others that flew off-deck without afterburners.

Current aircraft like the F/A-18 Hornet can be launched without afterburner in some, but not all, configurations.  For the most part the incremental safety margin and increased take-off weight means that afterburners are used for takeoff, but it's not strictly a requirement.


Several advantages:

Wing structures are hollow and voluminous in order to provide structural rigidity against flutter and carry flight loads.  This provides the space needed to store fuel.
On a conventional aircraft, placing fuel tanks in the wings places the fuel mass very close to, or on, the center of lift.  This dramatically reduces Cg shift during flight and reduces the size and weight of the tailplane to maintain stable flight.  It also reduces Cg shifts due to sloshing of the fuel inside the tanks, due to the limited constraints of longitudinal travel for the fuel in the tanks.
In the event of a crash landing, having the fuel in the wings keeps it away from the cabin and the occupants, reducing risks of cabin fires.
The weight of the fuel reduces the loading moment on the wing roots, reducing the weight of the structure needed to support the aircraft during flight.
Fuel stored in the wings either partially or completely eliminates fuel storage in the fuselage, leaving more room for passengers and cargo.

Disadvantages:

1) Fuel sloshing with in the tanks laterally as a result of turbulence, or uncoordinated flight, can lead to lateral weight shift and potential lateral instability.   At low quantities of fuel, and in prolonged uncoordinated flight, there is a chance that the engine can suffer fuel starvation simply because the fuel has flowed out of the sumps in the tanks These problems can be alleviated with proper fuel tank baffling and the use of feeder hoppers fed by the main tanks which the engine drinks from.

2)  On aircraft which utilize a siphon feed fuel system such as low wing aircraft, the fuel cannot be evenly siphoned from both tanks at once.   This is a particular problem in single engine aircraft, where separate fuel systems are not dedicated to one engine in particular.   In such cases the engine will feed off either the left wing tank with a right wing tank  and this is controlled by means of a fuel selector valve in the cockpit. On aircraft that do not have automatic fuel management systems, engine fuel feed must be manually selected.  Care must be taken to alternate feed from both tanks periodically to prevent a lateral imbalance and fuel quantity. Additionally this fuel tank switching schedule, if ignored long enough, can potentially lead to fuel starvation of the engine and a forced landing.  This is particularly problematic in the low wing light single engine aircraft such as the Piper PA-28 or Cirrus SR-2X, especially if the pilot has recently transitioned into this airplane after flying high wing aircraft, which use gravity feed fuel systems, and allow the engine to feed from both tanks at once.  Larger single engine aircraft like the TBM have automatic fuel tank switching systems to address this problem.   Large multi engine jet aircraft have dedicated fuel management systems which address these problems.


How is it an advantage for the L1011 to not right itself?

It's because, while neutral roll stability (tendency to stay at a bank angle until disturbed) is an undesirable characteristic for an aircraft that is flying straight and level because more attention is required to keep it there, it's a desirable characteristic while maneuvering.
Normally, you have to choose one or the other, so you choose positive roll stability because that's the priority for an airplane designed to cruise.
Airplanes that spend a lot of time, or are optimized for maneuvering, like aerobatic aircraft and gliders, tend to make neutral roll stability a priority.  This is a really desirable feature on a glider that spends perhaps a majority of its time in thermals in 30 degree banked turns.  When you spend extended periods turning, the tendency to hold a bank angle is a great feature.
As well, when flying on instruments, a tendency to hold a bank angle naturally is a useful feature.  You are generally either in level flight where you want positive roll stability, or are in a standard rate turn, where a tendency to retain the turn rate without input is nice to have.
So, an airplane that had positive roll stability while level and neutral roll stability while maneuvering (on purpose) can be the best of both worlds.


Can commercial pilot get paid for introductory flights with their own customers?

There are three parts to your question and the answer to all three is no. And there isn’t one specific place in the FARs that says you can’t do this, but reading Parts 91 and 135 along with appropriate ACs and Legal Opinions of the FAA leads most pilots to realize that they can’t do this.
§91.147   Passenger carrying flights for compensation or hire. contains a list of requirements that you must satisfy as well.

If you look for customers it is considered 'holding out' and according to AC 120-12A ‘A carrier becomes a common carrier when it "holds itself out" to the public, or to a segment of the public, as willing to furnish transportation within the limits of its facilities to any person who wants it.’ And if you are a common carrier, then for this type of operation, you must have a Part 135 certificate.

As a commercial pilot, you can be paid to fly someone in their airplane. Lots of commercial pilots do this. However, if you provide the plane then you are acting as a Part 135 operation and you can’t do it.

Getting paid is also not allowed. Since you can‘t do parts one and two of your question, you are acting under your Private Pilot certificate for the flight. At most, you can split the immediate expenses i.e. fuel, landing fees, etc. Even that is a bit dicey since you won’t have a ‘common purpose’ with the person you are flying. In other words, without holding out for customers, you wouldn’t have been making the flight anyway.

Not part of the question, but there are lots of things you can do with a commercial pilot’s license:

Corporate Pilot, Charter Pilot, Contract Pilot (for a private owner), Freight/Cargo Pilot, Ferry Pilot, Banner towing Pilot, Sight-Seeing/Tour Pilot, Agricultural Pilot/Crop Duster, Skydiver Pilot, Photographer Pilot, Airshow Pilot, Demo Pilot (aircraft sales), Medical Evacuation Pilot, Humanitarian/Charity Pilot, News/Traffic Pilot, Pipeline Patrol Pilot, National Defense or Border Patrol Pilot, Firefighting or Forestry Pilot.


What are the disadvantages of a Tail providing lift? (tandem-wings included)

A lifting tail just means lower static stability.

You are correct, flying in the downwash of the wing makes the tail less efficient. But that does not mean it is all bad: Since downwash increases with lift coefficient, the tail effectively sees a smaller angle of attack variation than the wing, so it maintains a healthy margin from stalling even while the wing is stalled. This helps to keep the aircraft controllable well into a stall (within limits, of course).

The reduction in downwash as the center wing stalls will even add a positive AoA gradient during the incipient stall which adds some more stability, making it harder for the pilot to command a further AoA increase.

And performance-wise, the download on the tail in conjunction with downwash actually might create a bit of thrust on the tail.

Concerning Rutan Designs: Their different looks are not for better performance but merely the expression of an oversized ego and his way of self-promotion.

EDIT:

The many downvotes I now collect for speaking my mind freely shows how well the self-promotion of Burt Rutan works. But it cannot bend the laws of physics which guide my opinion. Which I will continue to express freely.


During which part of the flight the effect of air resistance is more important?

The answer they are looking for is probably cruise. This is generally the longest part of the flight, so the losses from drag will add up. Most aircraft are optimized as much as possible to have good performance in cruise to save fuel and meet range requirements, so having low drag is more important in this part of the flight than others. This is also generally the section where the aircraft is traveling fastest. As Peter Kämpf showed, drag is highest at higher speeds, other than periods where landing gear, flaps, etc., are extended and add more drag.

As Jay Carr explained, drag is important at every point while the aircraft is in the air, affecting different areas of performance. During takeoff, drag will affect the runway distance needed, and initial climb performance. Low drag during descent is helpful, unless you need to get down faster, like in an emergency descent. Drag is probably highest during landing, because the emphasis is placed on having as much lift as possible at slower landing speeds, and this lift is created at the expense of higher drag.


What is the definition of “blade scatter” in gas turbine compressor dynamic balancing?

I assume there is an ellipsis somewhere in your source text, meaning the intended interpretation is "blade weight scatter", which does make sense in the context of dynamic balancing.

The meaning should be self-explanatory: the distribution of weights among nominally-equal turbo-machinery blades, which is important to keep the inertia tensor of the assembly as diagonal as possible when using the usual axis.


Need help to clarify the terms "arrival", "departure", "approach", "terminal" and "transition" fix for US STAR and SIDS

I am not an FAA controller or instrument rated but since you don't have an answer yet I will give it a shot.  If someone has a better answer please post:

Arrival:  IFR routes that start at radius about 30-50 NM from the airport.  This is where airplanes usually start their descent.  This can be controlled by en route or TRACON ATC.

Approach:  An IFR route that outlines a particular approach to the runway.  There are RNAV (GPS), VOR, and ILS approaches that are provided for an airport's runways.  You would file an approach during your IFR flight plan but could be modified by ATC as needed.  This is handled via ATC by approach control.

Terminal:  The area handled by a TRACON (for busy airports).

Departure:  Your IFR route filed when you depart from the runway.  This is handled via ATC by Departure.

Transition:  I am not so sure on this but I think this relates to going from arrival to approach.


Airway data is published in each country by their respective regulatory authority. This is published as a part of AIP(Aeronautical Information Publication).

This page contains links to some of the sites having electronic AIPs. The relevant data can be found in Part 2- Enroute(ENR). For example, this gives the details for UK airways.

I don't think there is a worldwide list as the airways of each country is controlled by the respective government through regulatory body and this information is updated periodically (in cycles of 28 or 56 days).


Who logs the flight hours for airline pilots?

At my outfit, both.

Pilots log their own hours in the logbooks and keep a rough mental track of hours flown to ensure compliance with Flight Time Limitation rules.

The airline will also log pilot hours to stay in accordance with FTL and compare rosters to actual hours flown. This also serves to create a legal record of who was flying the aircraft should that be required at a later date.

Many - including myself - use an electronic logbook that pulls the data from the airline, so no writing needs to be done.


When were commercial pilots first allowed to use glasses?

In the US, the department of commerce had an Aeronautics Branch. It was first responsible for civil aviation safety. On February 28, 1927 it published a list of the first physicians, who were qualified to give medical examinations for pilot licenses.

On December 31, 1926, the Aeronautics Branch issued the first air commerce regulations, that included medical standards. These standards discerned three levels of physical standards one for each class of pilot : private, industrial and transport. The standards included regulations for visual acuity. Private and industrial class pilots were allow to wear corrective glasses.


What is the constant in this formula for additional lift?

The formula you have given looks strange to me, I have never seen it before. But possibly I can help you with the following brief explanation about kinematic relationships when flying under wind conditions.

Flight path velocity (VK) is the vector sum of aerodynamic velocity (VA) plus wind velocity (VW), see sketch. - When flying in a headwind condition aerodynamic velocity will increase and a pilot will need to decrease Alpha to keep the lift constant. It is the opposite way around in a tail wind condition. Now a pilot will have to increase Alpha in order to keep the lift constant and additionally will have to pay attention not to come too close to Alpha max. Or increase thrust.

If one uses the sketched kinematic relationships properly one does not need an additional formula for analysis.


What are these diagonal devices above the leading edge of the V-22 Osprey's wing?

The protrusions you're asking about are vortex generators.

As to how they work, there is a separate Stack Exchange article on that: How do vortex generators work?

(Please note, the linked question/answer does not even MENTION the CV-22, and is thus not a duplicate question to this one.)


Best glide speed vs. best glide angle? Maximum glide range?

Is it true, that this best glide speed is given in terms of indicated airspeed IAS and hence is independent of the elevation?

Yes. The best glide speed needs you to fly at the optimum polar point, and with the same IAS you will fly at the same lift coefficient and polar point.

  To determine the glide path angle I suppose, that the ground speed and the sink rate is relevant.

No, the angle will be the same regardless of altitude (if we neglect Reynolds number effects for now). What does change is the speed over ground - this goes up with height.

  What is the resulting flight path angle when maintaining best glide speed? Does it change with decreasing elevation?

No, it doesn't. The glide path will be the same, only at higher altitude the airplane will fly faster and proportionally sink faster. What changes is the time scale, not the geometric scale.

EDIT:
The added graph is either given in TAS on the x scale and for a specific altitude, or it is given in IAS and valid for sea level to maximum ceiling (if we neglect Reynolds number effects for the moment)

P.S.: Terminology:

Altitude is the vertical distance from sea level to where an airplane flies. See here for more.

Elevation is the vertical distance from sea level to the ground or to an obstacle.

Height is vertical distance between an aircraft and the local ground.


Long pole on the tail of a Cessna, what could it be?

What you describe does not match any banner tow rig I am familiar with, and I have towed banners.

What it sounds like is a magnetometer, which might be on a survey aircraft. They can be on a boom (stinger) or sometimes towed.  I have seen them on Cessna 182, 210 and 208 aircraft, as tail mounted booms.

Magnetometers are typically used for geophysical survey work.  Towed magnetometers may be more sensitive and might be useful for detecting submarines, mines, etc. The P-3 typically has a rear boom with a magnetometer or magnetic anomaly detector (MAD).


Is there a speed needed to achieve flight?

There may be an ultimate lower bound, about where the ratio of random air motion to forward motion is near 1:1. But that is an extremely slow speed.

I've seen competitive balsa-wood gliders, weighing just a few ounces, achieve flight from a rubber band, going less than 1 mph, or a slow walking speed.

If the craft is light enough, the wings are big enough, and a little air is moving over them, lift is generated.


Cloud ceiling is measured from ground:

  height of the base of the lowest clouds ... that cover more than half
  of the sky ... relative to the ground

Cloud base is measured from sea level:

  ... the lowest altitude of the visible portion of the cloud. It is
  traditionally expressed either in m or feet above mean sea level


Is it okay to divert to another airport in IFR lost comms situations?

AIM 6−4−1. Two-way Radio Communications Failure

a. It is virtually impossible to provide regulations and procedures applicable to all possible situations associated with two-way radio communications failure. During two-way radio communications failure, when confronted by a situation not covered in the regulation, pilots are expected to exercise good judgment in whatever action they elect to take. Should the situation so dictate they should not be reluctant to use the emergency action contained in 14 CFR Section 91.3(b).


Why couldn't my aircraft depart fully fueled on a 44C day?

There are two problems:

First, at higher temperatures, the air is less dense; therefore there is less oxygen (by mass) in every cubic metre of it; therefore more air must be ingested by the engine (by volume) for the same quantity of fuel to be completely burnt. If the intake flow rate of air is fixed, then less fuel can be burnt and less power developed compared to a colder air temperature.

The second problem is that the lower density of air reduces the lift generated by the aircraft's wings at any speed. To make up for this the aircraft can travel faster.

In practise this means that aircraft operating in "hot and high" conditions—altitude also affects air density—will require longer runways to take off.

If it gets too hot then the aircraft might not have enough runway to get airborne.

For safety reasons the runway must be long enough for the aircraft to come to a stop if the commander decides to reject the take off at the last moment. But fast, heavy aircraft take a long time to stop; so this means the runway must be even longer.

If the aircraft is lightly loaded then it is not such a problem; there is less mass to accelerate and a lower speed must be obtained for take off. Thus a short flight simply takes a bit longer but still gets off the ground. But for AUH-SFO, this is a very long flight and will require a great deal of fuel to be taken onboard (at a guess I would imagine something on the very rough order of 80 tons). The specifics will vary by aircraft, and by how much is on them.

https://en.wikipedia.org/wiki/Hot_and_high


Do TSA regulations allow CFIs to start training non-citizens before the TSA has approved their training request?

This is addressed in the AFSP Candidate FAQ, which confirms that you can start training in category 3 as soon as all information has been submitted:

How long should I expect to wait after I have submitted my training event request?
[...]
Candidates in Initial, Instrument, and Multi-Engine training (category
3) may begin training as soon as AFSP receives all required
information, including the candidate's passport, fingerprints, the
fee. You and the provider will be notified once AFSP receives the
fingerprints and you have been granted Permission to Initiate
Training.

That's also what the regulation says, but the FAQ may be a little clearer.


What is this turbine engine panel that opens on landing?

What you saw is the thrust reverser of the engine, which redirects some of the airflow forwards and therefore helps slowing the aircraft down. The grid like structure are the cascade vanes. This is what it looks like inside the engine:

(Airbus A380 FCOM - Engines - Thrust Reverser System)
The blue arrows indicate the flow of the so called bypass air, which is air that goes through the fan (and is therefore accelerated), but does not go into the core engine. With the thrust reverser deployed, this air is redirected forwards. The core air going through the actual turbine engine will still exit at the back.
Since there is more bypass air than core air1, there is a net thrust generated in the forwards direction.
If you are wondering what the pilots are doing to engage reverse thrust, this is a picture of the A320 family thrust levers:

(image source)
The main thrust levers are pulled all the way back during the flare to the position shown in the image (labelled 0). To open the reverser doors, you pull up on the smaller handles at the front of the thrust levers. Once the reverser doors have opened, the thrust levers can be pulled backwards to add more reverse thrust (range labelled REV in image). To close the reverser doors, the thrust levers are moved back forwards and the smaller handles are pushed back down.
Note that on a dry runway reverse thrust does not slow the aircraft down faster (assuming auto brakes are used). The brakes on the main landing gear are capable of achieving the same deceleration without reverse thrust. Engaging reverse thrust therefore reduces brake temperatures and wear.
The thrust reverser doors can look different depending on the engine type. Based on your image, the aircraft you were on was equipped with IAE V2500 engines2. The reverser doors on the CFM56 engine, as used on some A320 family aircraft, look a bit different3:

(image source: Wikimedia)

1 The IAE V2522-A5 engines used on the Airbus A319 have a bypass ratio of 4.9 : 1 (source).
2 FlightAware shows a EWG4063 flight tonight from Munich to Dortmund and according to planespotters.net Eurowings uses IAE engines on their A319s.
3 The CFM56 engine is also used on the 737, but uses the cascade thrust reversers there (thanks to DeepSpace for pointing this out). See also Why is the CFM56 produced with two different thrust reverse options?


What's going on in this "confusing" TCAS Resolution Advisory video clip?

The TCAS responded to the other aircraft not following the flight profile that was observed earlier. If you watch closely, you will see that the other aircraft started to descend as well after the first resolution advisory is given.
The onboard TCAS responds by issuing the counter-movement to climb immediately.

The only thing that we do not know is what version of TCAS this is supposed to simulate, because newer TCAS systems can interrogate each other and issue resolution advisories not only based on own observed data, but also on data received from the opposite TCAS.

Related Question: How does TCAS work?

The entire situation could have been part of the training scenario, as this was done in a simulator, according to the YouTube description:

  Practising TCAS RA manoeuvers during our MCC course in a Boeing 747-200 full-flight simulator. This one was quite confusing when the TCAS' voice advised to climb just after having asked to descend.


Is it practical to descend in a lost communication scenario?

The rules on this are well-established and clear. They are laid out in FAR §91.185(c)(2). In particular, you should fly at an altitude which is (emphasis mine):

At the highest of the following altitudes or flight levels for the route segment being flown:
(i) The altitude or flight level assigned in the last ATC clearance received;
(ii) The minimum altitude (converted, if appropriate, to minimum flight level as prescribed in §91.121(c)) for IFR operations; or
(iii) The altitude or flight level ATC has advised may be expected in a further clearance.

For each segment of your route, you evaluate the minimum, assigned, and expected altitudes, and fly the highest. In this case, you'd fly at 9,000 feet on the leg where the MEA is 9000, and then descend back to 8,000 when the MEA drops to that altitude or lower.
If you lose your radios and squawk 7600 (or stop squawking altogether), ATC will expect you to fly those altitudes. They will provide separation between you and all other IFR traffic at 9,000 feet on the first leg, and 8,000 on the second leg. The only exception to this is if you encounter VFR conditions, in which case you should maintain VFR, land, and call ATC so they stop holding the airspace open for you.
In this situation, you should not worry about inconveniencing ATC or other traffic. We have these rules specifically set up so that nobody trades paint if a radio fails. ATC will manage IFR traffic separation for you. "Better in terms of traffic separation" happens when everybody follows the same plan.


What area to use for the lift/drag forces

If you're using equations with $C_L$ and $C_D$ you need a (single) reference area, $S_{ref}$:

$$L = q_\infty S_{ref} C_L$$
$$D = q_\infty S_{ref} C_D$$

For aircraft this is generally the wing planform area. However, for a satellite, wings aren't going to be of much use, so the area upon which molecules will be impinging (such as the nose cone or cross sectional area normal to the flow) would be a more useful choice. Your coefficients will vary depending on which area you choose. Note that it really doesn't make sense to try to model the "lift" of a satellite.

On that note, satellites, especially at altitudes as high as 500 km, are essentially ballistic, so the ballistic coefficient is perhaps a better choice:

$$ BC = \frac{M}{C_d A} $$

Here $A$ is the cross sectional area of your object, but for all intents and purposes it's very similar to $S_{ref}$. We can substitute it back into the drag equation to get something useful for satellites:

$$ D = \frac{q_\infty M}{BC} $$


Is an additional rotor useful on a coaxial rotor configuration?

You could use the second rotor to provide anti-torque function only, as Arthur Young did when developing his helicopter test models at Bell during WW2.  In that case the upper rotor did all the lifting and the lower one had blades that were at 90 degrees and just made drag to generate a cancelling torque.

But that is really inefficient, and Young quickly moved on to using an anti-torque tail rotor (with a decently long arm to minimize the thrust it had to make), not wanting to go the whole-hog coaxial route, with all its mechanical complexity.

So if you want to have a coax machine to do away with a tail rotor, you might as well design it so both rotors are lifting (to realize the efficiency you are seeking by going with co-ax in the first place) and you can easily get yaw control by using a mixing system operated by the anti-torque pedals that adds collective pitch to one rotor and decreases collective pitch to the other rotor equally, in a way that the total lift is unchanged but a yawing torque can be created and varied.  And there you go.


Is it possible to use thrust reversers to taxi backwards?

This is called Powerback, most aircraft can do it, but it is not done very often.

In a jet aircraft, the three main problems are:

Reverse thrust tends to throw a lot of debris into the air because the exhaust is deflected to the sides and up and down too. This debris can damage the engine itself, other things on and around the aircraft or injure someone on the ramp. It is less of a problem for aircraft with tail-mounted engines (so DC-9s often used powerback), but that engine configuration is not used as much any more in transport aircraft, as it is less aerodynamically efficient.
A related problem is that the compressor might suck in its own hot exhaust gases. This might lead to temperature-induced damages in the last (high-pressure) stages of the compressor and health issues for passengers, since the air conditioning system works with bleed air from the compressor.
Reverse thrust is rather inefficient on jet engines, so it uses a lot of fuel.
As Casey mentioned in the comment below, the pilot has to be careful using the brakes during powerback: the main wheels are very close behind the centre of gravity, so harder braking can lift the nose wheel, causing the pilot to lose control and even causing damage to the tail if it hits the ground (“tail-tipping”).

So a tug is both cheaper and safer.

In propeller aircraft, reverse is more efficient and does not throw up as much debris, so it is sometimes used. But a tug is still preferred because transport aircraft don't have any rear visibility, so the pilots can't see where they are taxiing. With tug the driver can see behind the aircraft, and a ground marshaller walks along side each wingtip with an intercom  connected to the plane.

Lastly, since aircraft are able to turn almost on the spot using differential braking and thrust and 180-degree nosewheel steering, at airports with few facilities there is generally enough space around the aircraft to permit the pilot to reverse out easily.


Can the ECS work in an unpressurized cabin?

If the cabin is unpressurised, the temperature could be controlled to a limited extent- this is usually done in a number of helicopters.

You can certainly cruise at 20k feet without a pressurized cabin - WWII pilots regularly did this with supplemental oxygen and heated clothing- though I'd hardly call it comfortable.


They are flaps or doors on the engine cowling that open up in order to provide increased cooling airflow for the engine. They look like this when open. They are generally controlled by a handle in the cockpit (some aircraft have electric cowl flaps with an open/close switch).

The disadvantage is that the open flaps also increase drag. So on airplanes equipped with cowl flaps, they are generally opened for low-speed, high-power situations such as takeoff. This is the harshest operational regime for the engine since it is at its highest power and relatively low cooling airflow due to low airspeed. They are then closed either reaching cruise or reaching a point where the airplane can transition to a lower-power, higher-speed climb profile.

They're not specific to radial engines, but do tend to be more common in older aircraft (there are exceptions though). Newer airplane and engine designs are more likely to have sufficient inherent cooling airflow to not require cowl flaps.

The photo above comes from AVweb, which also has a nice article explaining more about the function and usage of cowl flaps.


What are the "lumps" in the A380 flight-deck?

They are a different design of computer mouse:

As far as I can tell, the front disk is a track pad and the model in your picture has the mouse buttons on the front instead of the sides:


Is flutter speed always smaller than divergence speed for aircraft?

Flutter speed will usually be smaller than divergence speed. Flutter will appear first because as a phenomenon, by definition, describes the state of the deformation of the wing where it deflects for example up and down in a vibrating fashion. Divergence on the other hand is when the moments from the aerodynamic forces acting on the wing are larger than the restoring moments due to structural stiffness thus resulting in failure.

For the sake of simplicity -since the entire calculation is pretty lengthy- let's imagine an airfoil at an angle of incidence θο that's been twisted by an angle θ due to aerodynamic loading. This additional angle θ is used to measure the twisting strain (dynamic) energy 0.5*K*θ^2 where K is the stiffness of the airfoil - much like a spring's K constant. An increase in speed will increase angle θ and the corresponding strain energy stored in the structure. When the speed reaches the divergence speed the restoring forces are smaller than the aerodynamic forces and the angle θ becomes infinite but since infinite is impossible in reality, the structure fails.

Very early airplanes (Wright, Langley) had major divergence problems and where unable to fly although they had airfoils capable of generating the lift necessary. The same airplanes with stiffer wings in later designs where able to fly. Modern airplanes due to proper design and stiffer materials have divergence speeds higher than flutter speeds. Divergence is a measure of the overall stiffness of the structure and is also used in order for the aircraft to get certified.


Why would a stretch variant need a larger horizontal stabilizer?

When the fuselage is stretched, the arm of the horizontal stabiliser is increased, and hence it's effectiveness increases linearly with the fuselage length.

However, because the mass is distributed further away from the centre of gravity, the pitch moment of inertia increases too.

If the fuselage would be modelled as a uniform rod, the moment of inertia in pitch would be $\frac{1}{12}mL^2$, with mass $m$ and length $L$.

source: hyperphysics.phy-astr.gsu.edu

You see that the moment of inertia increase with the square of the fuselage length, while the effectiveness of the elevator increase linearly with fuselage length. The nett result is that the pitch response of a longer fuselage with the same horizontal stabiliser/elevator is reduced.

In addition to the change of inertia, the heavier aircraft needs more powerful flaps (double-slotter vs single slot before) which causes a bigger pitch moment change.

Therefore a stretched aircraft needs a more effective elevator.

As for the meaning of "flying together" I assume that this means that the software solution for the 787-10 controls the pitch moment of the aircraft not only by changing the elevator angle, but also uses control surfaces on the wing.


What technology is being moved forward to keep pilots from crashing planes?

Nothing.

At present, there are no serious technological plans to prevent pilots from intentionally crashing a plane. There are discussions about making sure that there are always two people in the cockpit, and at some point policies might be changed to make it easier for pilots to enter the cockpit (even if no-one in the cockpit wants them to), but ultimately we trust the pilot to do whatever necessary to ensure the safety of the aircraft (within certain bounds; see the flight envelope protection system in Airbus aircraft).

By limiting pilots' ability to control their aircraft, we seriously limit their ability to legitimately deal with emergencies. See, for example, cpast's example of one pilot having a medical emergency and the other pilot not being able to divert because they can't get approval. Even if both pilots are conscious and able, such a system would slow them down when responding to emergencies.


Does a quadcopter have flight modes beyond traditional aircraft?

As DeltaLima noted, pretty much all flight modes of a quadcopter are "non-traditional" -- they're a relatively new aircraft design.

Most quadcopter designs lack anything resembling "wings", so they can't "fly" in an "X-Wing" orientation (with the rotors producing entirely lateral thrust) -- at least not as we traditionally define flight.

They can, as you surmised, do a climb-and-run maneuver in that orientation: Gain a lot of altitude by using vertical thrust, tilt the platform near-90-degrees in the direction you want to travel (so your thrust is pretty much lateral), and accelerate in that direction while rapidly losing altitude.

I've no idea if this is more or less efficient than the usual slight tilt they fly with, but it's certainly less stable since you're in vertical free-fall and would need to redirect thrust to be vertical again with enough time/altitude to arrest the descent before an ungraceful impact with the ground.

  X-Wings work so well because the microgravity environment of deep space isn't trying to drag you back to an impact with the ground - it wouldn't work well deep in a planet's gravity well, which is where most of our aircraft operate.
  Of course if you had access to a microgravity environment with an atmosphere you could configure a quadcopter to fly like an X-Wing fighter…

The quadcopter's thrust configuration does open up the option for some interesting maneuvers though.

It's theoretically possible to "flip" a quadcopter (around at least 8 axes) if you have sufficient altitude (especially if the rotors can be reversed in flight to assist in the maneuvers).

It's also possible to "rock the wings" (really rocking the whole platform) in many directions by alternating thrust on pairs of rotors.


Jet engines are only efficient at high altitudes and high speed (25,000+ feet or so and 300+ knots or so true airspeed).  The cost of making and operating an airplane capable of flying there is very high, and most general aviation flights have no need of such performance (or expense) hence, propeller airplanes.

Reciprocating engine propeller airplanes are relatively efficient at low altitudes and airspeeds, they are more economical for the average types of general aviation flights.  They are also much cheaper to build and operate than a turbine powered airplane.

Turboprops fill the efficiency gap between reciprocating and pure jet engines, being most efficient at mid altitudes and airspeeds.  Still more expense and performance than most general aviation flights need though.


Does 14 CFR 25.1310 apply to hydraulic systems?

Usually this link below can be very helpful in finding guidance for a particular regulation (e.g. 25.1310). In this case there isn't any guidance for 25.1310.

https://www.faa.gov/aircraft/air_cert/design_approvals/transport/rules_acs_policy/

Next try the preamble for when this regulation was passed or introduced and see if the FAA provided any guidance on their intent for the regulation. The FAA discussed an EWIS (Electrical Wiring Interconnect System) accident which only confuses the intent. However I briefly perused the preamble.

http://rgl.faa.gov/Regulatory_and_Guidance_Library/rgFinalRule.nsf/0/81B77634BED9EAA78625738E007123B3?OpenDocument&Highlight=amdt.%2025-123

25.1310 is in Part 25 Subpart F and most of these regulations (e.g. 25.1309) apply to all systems (e.g. hydraulic, electrical, pneumatic, etc.). Best of luck I hope this helps.


What is this INOP instrument and when is it safe to fly with INOP instruments?

It is a standby display, specifically a DDRMI (Digital Distance Radio Magnetic Indicator).

The aircraft can be dispatched with inoperative equipment. The process is controlled by a Minimum Equipment List (MEL). The operator will have an MEL for each type of aircraft in their fleet. The MEL is approved by the regulatory authority (FAA, CAA, etc.) and specifies what may be inop and associated restrictions.

I don't know what the BA MEL for the A319 is, but here's a snip from the FAA's Master MEL (MMEL), which is the guidance for each operator to use when creating their MEL.

Following this guidance, the MEL would say you can dispatch with the DDRMI INOP if the FAR equipment minimums are met. That (at least in the US) is along the lines of "navigational equipment necessary for the planned flight".


How does an aircraft distribute fuel equally between powering the turbines on the engine and injecting it into the afterburner?

The aircraft fuel system does not  distribute fuel equally among the afterburner and the engine's core (i.e. the compressor-combustion chamber-turbine part). It distributes fuel in such a way that the combustion is maintained in both the combustion chamber and afterburner and the required thrust is produced.

Consider the case of F-15 E/I/S or F-16 C/D powered by PW F100-PW-229 (data from jet-engine.net). Here, the thrust and SFC (specific fuel consumption) for dry and wet thrust are given as 17800/29100 lb and 0.726/2.060 lb/lb/hr respectively.

Simple calculation yields fuel consumption rate of 59946 lb/hr and 12923 lb/hr with and without afterburners. This answer by @KeithS gives the fuel consumption of F-16 with and without afterburner as 64000 and 8000 lb/hr respectively. Also note that fuel consumption varies greatly with other conditions like altitude, external stores etc.

It can easily be seen that the use of afterburner increases fuel consumption by 5-8 times and most of this has to go into the afterburner. So, once the pilot punches the afterburner, the fuel system delivers much more fuel to the afterburners than to the 'core' of the engine. These decisions are made usually by the aircraft computer/engine FADEC based on pilot input in all modern combat aircraft.


Can wing clouds caused by a high angle of attack be recreated in a lab? Also, why doesn't this work for smaller wings (e.g. r/c planes)

The sudden fog due to the fast (and hence adiabatic) expansion of air is re-created, in many laboratories, in the simple cloud chamber.

For those that haven't seen one (they are fast disappearing from school labs due to 'radiation risk'): it is a small, usually round chamber with a window. Inside, there's a a small amount of water to ensure a water-vapor saturated air. As the chamber is closed, the water is in stable equilibrium with its vapor. The chamber is connected to a hand pump that resembles a bicycle pump, but working in reverse. When you pull the pump handle, you make a partial vacuum in the chamber, and due to the sudden descent in pressure, the temperature drops too, and some of the water vapor inside the chamber condenses. If the pull is light enough, the condensation will take place only along the trajectory of the alpha- or beta particles emitted by a suitable source placed inside. But if you pull hard enough, the whole chamber fills with fog.


Why isn't the Presidential 747 "Air Force One Heavy"?

Practically speaking, the 'heavy' designator ('super' for A380 and An225) is to help enforce separation requirements due to wake turbulence. In case of AF1, it is not as if other aircraft are going to be allowed near it, so the designator is redundant.

Regulation wise, FAA JO 7110.65T Section 4. Radio and Interphone Communications, specifically states that the 'heavy' designator should not be used:

  When in radio communications with “Air Force One” or “Air Force Two,” do not add the heavy designator to the call sign. State only the call sign “Air Force One/Two” regardless of the type aircraft.


Why is everything in aviation written in abbreviations?

For the weather, those come from ye olde days of teletypes when it took a significant amount time to transmit characters. Yes, they should go away.


What does it mean to maintain a positive g loading?

Short Answer

In straight and level flight, it means don't push over too fast.  Doing so gets you "light in the seat" and things may fly about the cockpit/cabin.  In some aircraft, negative "g" can make the oil "flow up" away from the sump and begin to starve your engine of much needed lubrication. (Example: T-34C, trainer, limited to 10 seconds inverted flight.  Straight and Level inverted flight is -1 "g.")

More Answer

You want to avoid flying with negative "g" in a variety of circumstances,  depending upon how the aircraft is designed.

Example: In a helicopter, negative "g" can have dire consequences.
On the teetering, semi rigid rotor heads in the original Huey, for
example, unloading the head can lead to mast bumping, which can
lead to catastrophic failure of the mast, and then some death.
Counter Example: Flying a Pitts Special, or an F-18, the aircraft is
built to withstand some negative "g" due to their needing to fly
particular maneuvers.

"G" is a natural part of flying, but "how much" varies with design.

Whenever you turn the aircraft, you will add a little bit of "g" load since "g" is a measure of acceleration.  Vector sums based on angle of bank will tell you how much "g" you can expect in a level turn at constant speed.

Example: a 60 degree angle of bank adds an additional "g" compared to
level flight, and you feel a bit of a push into your seat.


Why is a combustor in a gas turbine engine asymmetric?

That drawing in the question is not really representative, here's a CFM56 combustor:

— faa.gov

The bulge the artist used, is actually a turn/inclination for aligning the combustor with the more outboard first stage turbine.
Here's a more gentle turn in a bigger engine:

— Flight International