What can pilots do to spot the onset of hypoxia?

Yes, all pressurized aircraft have cabin altitude (= altitude at which the same pressure as currently in the cabin normally occurs) indicator with alert when it exceeds safe value.

On Helios 522 that alarm did sound. The crew however mistook it for configuration alarm which only makes sense during take-off roll and thus considered it spurious. When the technician they called realized it was cabin altitude warning, the pilots were already too confused to carry out his orders.

The symptoms are already listed in the other answer. The problem is that the initial symptoms feel just like fatigue. One starts to feel sleepy and at that moment one might not realize it could be due to hypoxia as mental capacity is already reduced.


How can I find out the reason for an aborted takeoff?

In addition to listening to ATC audio recordings as suggested by previous answers or comments, you can also try to visualize the traffic situation at the time of the event using the playback feature of flight tracking websites like FlightRadar24.

On those radar images, you can possibly see other aircraft, whether there was the danger of an imminent runway incursion, maybe the go-around of another aircraft nearby or something similar which prompted ATC to cancel the takeoff clearance. If you combine those radar playbacks with the audio recordings that you already know, you might get a pretty accurate picture of what actually happened.


Why does the yoke "stick" in a turning position?

I think it's a little bit of both -- for most aircraft, how they behave in a turn is a byproduct of their designed aerodynamic properties. This question is actually quite complex to answer. Let's assume you're talking about a simple light aircraft, where control surfaces are mechanically linked to the controls that move them -- this ensures that anything you feel is related to what's happening to the plane, and not necessarily to anything more complex (like a fly-by-wire computer, or a hydraulic linkage with some degree of hysteresis).

Aircraft turns are divided, by the CAA & FAA at least (see the FAA's Airplane Flying Handbook, Chapter 3) into three main categories:

Shallow turns (roughly speaking, <20º angle of bank). These tend to become shallower if left alone.
Medium turns (roughly speaking, 20º < $\theta$ < 45º angle of bank). These turns tend to be stable without further pilot input.
Steep turns ($\theta > 45$º). These tend to become steeper if left alone, sometimes dramatically so.

Let's look at these in a bit more detail, with some explanation as to why these effects occur.

Shallow turns.
These tends to become less steep as the turn progresses, and most aircraft have a natural tendency to decrease the angle of bank throughout the turn. This tendency to lessen the angle of bank arises, I believe, entirely as a designed aerodynamic feature of the aircraft to have lateral stability. As shallow angles of bank are essentially a situation that's is but a small perturbation about flying straight and level, it's desirable for the angle of bank to decrease back to zero if left alone. If that isn't the case, the aircraft stability has to be actively maintained by constant manipulation of the control surfaces (which is tiring or impossible for a human). This stability can be achieved through design features, such as (i) the dihedral of the aircraft's wings, (ii) their sweep, and (iii) their height position -- if high, there is an increased degree of lateral stability due to the centre of mass of the aircraft being below the tilted plane of the wings, and, if disturbed slightly, it experiences a force $F\approx mg\sin\theta$ to "pull" the wings back upright again. The sole purpose of any degree of wing dihedral -- the angle they make with the horizontal -- is to improve lateral stability. If a perturbation causes one wing to drop, the resultant (unbalanced) force will produce a sideslip in the direction of the downward wing. In effect this is analogous to "creating" a flow of air in the opposite direction to the slip. This flow of air will strike the lower wing at a greater angle of attack than it strikes the upper wing. The lower wing will thus receive more lift and the airplane will roll back into its neutral position. Many small aircraft have a slight degree of dihedral on the wings. A similar effect occurs with (ii) swept wings -- when a disturbance causes an airplane with swept back wings to slip or drop a wing, the low wing presents its leading edge at an angle that is almost perpendicular to the relative airflow. As a result, the low wing acquires more lift, rises and the airplane is restored to its original attitude. As an aside, you don't really notice you're in a shallow turn, aside from the fact that you're continually applying a little bit of stick and rudder. The $g$-loading is minimal.

Medium turns.
In this case, the aircraft is in a metastable state -- it will carry on at a constant angle of bank, but a `shove' to either side will result in the bank increasing or decreasing as appropriate. By this point, $\cos\theta\neq1$, and the outer wing is really generating a lot more lift than the other one -- and thus you'd effect the angle of bank to increase, as it pulls the aircraft into the circle. The effects discussed above, however, still apply, and provide an effective restoring force back to the normal attitude. In a medium turn, aircraft are designed to have these forces balanced, and, in practice, you often need little-to-no aileron and almost no rudder to do a coordinated medium turn in a light aircraft. If it's properly trimmed, you can take your hands off the controls and sit there merrily going around in a circle. Depending on your speed, the $g$-loading is apparent, but not great.

Steep turns.
By this point, one wing is generating almost no lift, and the other is generating quite a lot. We've gone beyond the designed stability point of a medium turn, and the angle of bank tends to increase as the outward wing pulls the plane of the aircraft towards its axis of turn. This type of turn actively requires pilot input to maintain a constant angle of bank, and, depending upon the speed, it can physically be quite hard work. The $g$-loading of the wings is significant, and, as the stall speed of an aircraft approximately increases as the square-root of the $g$ factor experienced, it's entirely possible to enter an accelerated stall or even a spin here. You notice the angle of bank, and feel the odd attitude of the aircraft. This phenomenon is called the overbanking tendency.


Why aren't there aircraft with forward-mounted vertical stabilizers?

From the image you can see that a vertical stabilizer mounted behind the aircraft CG imparts a restoring moment to a yaw disturbance which increases as the yaw movement increases. If the fin were placed on the nose of the aircraft, ahead of the CG, the moment would amplify the yaw disturbance, which is destabilizing.

An actively controlled rudder could be located ahead of the CG, but cost and complexity normally limit this to things like missiles.


Does a VNAV PTH descent need the Forecast Descent winds?

Yes, a VNAV PTH certainly needs descent winds so as to calculate and construct the most efficient flyable PATH. The PATH as we know. is built backwards from the landing RWY threshold to Top Of Descent (TOD).
Before I continue, I must say that sometimes managing VNAV PTH can become an unnecessarily complex task, if that's where you're coming from. We always have the alternative of lower levels of automation.
Flyability of the PATH means that the airplane should be on the FMC calculated 3 dimensional PATH  as well as the FMC calculated SPD at all times during descent, approach and landing. This depends on accurate depiction in the FMC of altitude and speed limitations, hopefully no changes to the lateral path, ie routing, and accurate wind data etc.
Small components of Head Wind or Tail Wind may not make it impossible to fly the PATH, but as the HW or TW component increases, it can make it very difficult to maintain and the SPD variations, especially in the upward direction and at altitude can be nerve-racking at times on certain types.
Try flying eastbound into TOKYO (Narita) on VNAV with 600+ kts of Ground Speed due 120+kts TW component without feeding the final cruise and descent wind data - guaranteed 'fun'n'games for the pilot and a possible violation. There's an 18,000 ft crossing restriction which, may become impossible to comply with depending on when the pilot catches on to the problem.
There is always recourse to the use of Speedbrakes if the airplane goes above the calculated profile, and Thrust if it goes below that profile. But the use of either of these indicates a deviation from the most efficient descent, and costs fuel.
In the ultimate analysis, @Stamatis Vellis, while one may not bother to put in any winds for  a 40 minute flight at FL 250 with light winds aloft, why willingly transgress the VNAV Speed Band (referred by you as +/- 12 kts), waiting for the FMC to automatically 'flip' from VNAV PTH to VNAV SPD.
VNAV PATH also represents fuel savings - my take is that when a facility exists, why not use it? 2 minutes spent on putting in effective wind forecasts, can make a more optimized, fuel efficient flight, more comfortable speeds, lower workload, more headspace for the pilots to monitor and make better tactical decisions ALL of which has direct safety impact.


What does it mean for a wing's lift distribution to be elliptical when the planform is not?

The (local) lift depends on many factors - not only the chord but also the profile, angle of incidence - and even up to the actual local flow. Without knowing the details of the actual wing, the distribution of lift can be hard to calculate.


Difference between engine rev up and run-up

In general English usage, including in aviation, "rev up" is a verb form describing the act of increasing the speed of something.  "Rev up the engine" just means give it a shot of power to make it go faster.

"Run up", as used in this case, is actually a noun, describing a procedure to test an engine against go-no-go criteria.  "Do an engine run-up" means perform the run-up procedure, which may include accelerating the engine to a specific speed to put things under a bit of stress, and testing various systems while at speed to detect degraded or failed components or subsystems that are revealed only when under stress.


How do you convert true airspeed to indicated airspeed?

Short Answer

Getting to grips with Aircraft Performance and Calibrated Airspeed are two good places to start!

The short answer:

From TAS to IAS $IAS=f(TAS)$:

$$IAS = a_0 \sqrt{5\left[\left(\frac{\frac{1}{2} \rho {TAS}^2}{P_0} + 1 \right)^{\frac{2}{7}}-1\right]} + K_i $$

From IAS to TAS $TAS=f(IAS)$:

$$TAS = \sqrt{\frac{2 P_0}{\rho}\left[\left(   \frac{ (\frac{IAS - K_i}{a_0})^2 + 1}{5}  \right)^{\frac{7}{2}} + 1 \right]} $$

WARNING: the units should be taken as SI, ($\frac{m}{s},\frac{kg}{m^3},Pa$).

In particular:

$a_0$: speed of soundat sea level in ISA condition = $290. 07 \; \frac{m}{s}$
$P_0$: static pressure at sea level in ISA condition = $1013.25 \; Pa$
$\rho$: density of the air in which you are flying $\frac{kg}{m^3}$
$IAS$: indicated Air Speed $\frac{m}{s}$
$K_i$: is a correction factor typical of your aircraft. You should find it in the POH.

How to get to this formula, see the long answer below.

Long Answer

From the definition of dynamic pressure:

$$ q_c  = \frac{1}{2} \rho v^2 $$

Where $v = TAS$, I am assuming you are interesting in subsonic speeds (cross-country flight), so we don't consider compressibility effects for the CAS:

$$CAS = a_0 \sqrt{5\left[\left(\frac{q_c}{P_0} + 1 \right)^{\frac{2}{7}}-1\right]} $$

Substituting the dynamic pressure definition in the $CAS$ as a function of $TAS$

$$CAS = a_0 \sqrt{5\left[\left(\frac{\frac{1}{2} \rho {TAS}^2}{P_0} + 1 \right)^{\frac{2}{7}}-1\right]} $$

Where $a_0$ is $295.070 \; \frac{m}{s}$ and  $P_0$ is $101325 \; Pa$. the density $\rho $ is the density at your altitude that day, you can get it from International Standard Atmosphere calculator or table/formulas.
If you measure it from your aircraft instruments $\rho = \frac{P}{RT}$, with $R=287.058 J kg ^{-1} K^{-1}$. You should give in Pressure in Pascal (not $hPa$) and most important temperature in Kelvin $K$.
Reverting the formula above (double proof is appreciated):

$$TAS = \sqrt{\frac{2 P_0}{\rho}\left[\left(   \frac{ (\frac{CAS}{a_0})^2 + 1}{5}  \right)^{\frac{7}{2}} + 1 \right]} $$

Being
$$
IAS = CAS  + K_i \\
CAS = IAS - K_i
$$

Where $K_i$ is a correction factor typical of your aircraft. You should find it in the POH.

Finally we get TAS as a function of IAS $TAS=f(IAS)$

So:
$$TAS = \sqrt{\frac{2 P_0}{\rho}\left[\left(   \frac{ (\frac{IAS - K_i}{a_0})^2 + 1}{5}  \right)^{\frac{7}{2}} + 1 \right]} $$


What is Neil Armstrong teaching in this image?

1)  The triangle shape represents an aircraft-- imagine something like a supersonic version of a Gee Bee racer.  The thing at the leading edge of the vertical fin is the canopy.

2) Here is a sketch that offers an educated guess about parts of the diagram that are either cropped, or hidden behind Neil Armstrong, in the original photos.  Also, for added clarity, labels have been added to the dashed lines representing the horizon, and the aircraft's longitudinal axis.  Note that for the diagram to make sense, the wings must be attached with zero incidence relative to the longitudinal axis of the vehicle, or the vehicle may be a flat-bottomed wingless lifting body.   Only the green vectors represent actual forces.  "L" is the lift vector, "D" is the drag vector, "W" is the weight vector, and "T" is the thrust vector.  Note that "D" is parallel to the flight path, "L" is perpendicular to the flight path, and "W" is perpendicular to the horizon. "T" is drawn in this sketch as nearly, but not quite, parallel to the aircraft's longitudinal axis-- in the original, the direction of the "T" vector is about midway between the direction of the aircraft's longitudinal axis and the direction of the flight path.  No attempt has been made in this quick sketch to make the force vectors add to zero.  We can't see enough of the original to guess whether the force vectors as drawn there would add up to approximately zero or not.

3) The vector labeled "flight path" in this sketch was labeled "V" (for "velocity") in the original.  It represents the aircraft's instantaneous direction (and speed) of travel through the airmass.

4) In the original, the line representing the orientation of the longitudinal axis of the aircraft was simply an extension of the flat bottom of the aircraft; it ended up getting displaced upward a bit in this sketch. This wasn't intentional but does have the effect of causing the line to pass closer to where the aircraft's CG would likely be. The angles of interest can be represented accurately regardless of whether or not the line representing the orientation of the aircraft's longitudinal axis actually passes through the CG or not-- we just need a reference line that is parallel to the aircraft's longitudinal axis.

5) Another detail that ended up different from the original in this quick sketch is the order of the angles illustrated on the left-hand side of the diagram.  In the original, running from right to left, the order is gamma, alpha (this letter has been rotated about 45 degrees clockwise so it looks almost like an upside-down gamma), theta, while the order in the attached sketch is theta, gamma, alpha.  This has no effect on the meaning of the diagram-- the same greek letters are still associated with the same illustrated angles. A confusing point about the upper photo is that it is cropped in such a way that at first glance the angle labeled "theta" appears to duplicate the angle labeled "gamma", but of course this is not actually the case.

6) It appears that the curved line represents the surface of the earth, the overlined "R" represents the radius of the earth, and "h" represents the aircraft's height above the earth's surface.  Neil is probably explaining that at very high speed, orbital effects start to come into play, reducing the need for lift.


What happens when the logbook of an aircraft is lost?

In order to state the plane is airworthy you must be able to show that all AD's have been complied with and that the aircraft is within annual (or 100 hour) inspection; these proofs are typically found in the logbook so no, without the logbook your aircraft is probably not airworthy. It may be possible to fly the plane legally in the US anyway if you receive authorization from your FSDO (which, I believe, would be a "ferry permit").

It's not legally required that your logbook be complete to the beginning of time, just that it shows the current requirements are met (along with the signatures/cert numbers of the AI's that are stating them to be met). However, an incomplete logbook is very important from a resale point of view. Not having complete logs will make a plane very difficult to sell and will certainly affect the price most purchasers would be willing to pay.


Why is vortex state impossible in autorotation?

OK -- first, a quick review of what vortex ring state is.  I'll be brief, but there's more detail over here: What is "settling with power" and how does it differ from vortex ring state?

Vortex ring state (VRS) occurs when the rotor's shed vortices begin to recirculate into the rotor system, effectively stalling out the rotor and significantly decreasing the total thrust produced.  It is one of 4 working states of the rotor, 3 of which are described in the picture below (note: descent rates are approximate.  What really matters is the ratio of the velocity induced by the rotor to the helicopter's descent speed).  The propeller working state is the normal working state of a helicopter.  VRS is the second state shown, where descent rates are relatively low (and forward flight speed is typically very low/zero), and the windmill-brake state is what you'd see in autorotation.

In the following plot (from Leishman's Principles of Helicopter Aerodynamics), these working states are superimposed on a graph of climb velocity and induced velocity at the rotor disk.  In short, VRS occurs when you're not descending fast enough to let the downwash be blown upward and you're still trying to produce thrust.  One example would be a helicopter attempting to hover above its hover ceiling (so, even at max power, it cannot maintain altitude and has a small, negative climb velocity ratio if referenced to the below plot).  As a result, it begins to descend at an increasing speed (and, by corollary, it is falling "into" its own downwash as its downward speed increases).

So why is autorotation a way out?  Autorotation is what happens when, in a sense, you stop trying to hold yourself up.  In autorotation, the thrust produced by the rotor is minimal (depending on how you do your bookkeeping of forces acting on the aircraft) during descent.  As a consequence, the aircraft is descending so quickly that the rotor wake is actually above the helicopter!  Also, while the rotor is producing some lift, and hence some downwash, the induced velocity of the downwash in the vertical direction is very small compared to the velocity of the relative wind going through the rotor disc (in the opposite direction of the downwash).

Putting this all together in different words: vortex ring state is sustained by the pilot trying to keep pouring power into the rotor system while descending into his or her own downwash (without changing forward flight speed or tail rotor thrust, as mentioned in this neat article: http://www.rotorandwing.com/2015/09/01/flying-through-the-vortex/).  He or she is producing downwash by producing thrust, and, as the descent speeds more or less balance with the downwash velocity, the same aerodynamic forces that produce the thrust end up recirculating the downwash through the rotor.

To go into autorotation, the pilot drops collective and throttle to zero and lets the aircraft fall (more or less -- it's a little more nuanced, but that's a separate question), which, in turn, drops the induced velocity of the downwash such that it is much smaller than the vertical speed of the aircraft, allowing the vortices move with the relative wind away from the rotor (upwards) as the rotor enters the windmill-brake state.  Since there is no mechanism to hold the vortices close to the rotor (or produce them in the first place), the vortices cannot recirculate and induce VRS.


How to decide which aerodromes should have Electronic Terrain and Obstacle Data?

An aerodrome or airdrome is a location from which aircraft flight operations take place, regardless of whether they involve cargo, passengers, or military. Aerodromes include small general aviation airfields, large commercial airports, and military airbases.

  An airport is an aerodrome with extended facilities, mostly for commercial air transport. Airports often have facilities to store and maintain aircraft, and a control tower. An airport consists of a landing area, which comprises an aerially accessible open space including at least one operationally active surface such as a runway for a plane to take off or a helipad, and often includes adjacent utility buildings such as control towers, hangars and terminals. Larger airports may have fixed-base operator services, airport aprons, taxiway bridges, air traffic control centers, passenger facilities such as restaurants and lounges, and emergency services.

With this definitions of aerodrome and airport from Wikipedia, we understand that all airports are aerodrome but not all aerodromes are airport i.e. airport is a subset of an aerodrome.

The Civil Aviation Safety Authority under CASR part 139 classifies the Aerodrome into below categories:

Certified Aerodromes
Registered Aerodromes
Other Aerodromes - more than 9 but not more than 30 passengers
Other Aerodromes - operations under proposed CASR part 135


Clarification on autogyro thrust formula

In vertical autorotation, with a constant sink velocity, the lifting force produced by the rotor is exactly equal to the weight of the gyro, since any difference between weight and lift would cause an acceleration, and we're considering a constant sink velocity, with zero acceleration.
In a dive under autorotation, with a stable dive path, the force produced by the rotor is higher than the weight of the gyro, since the tip-path plane of the rotor is tilted back, so you have a rotor drag component that has to be added (vectorially) to the vertical component (equal to the weight) in order to calculate the total rotor force.


Why is carburetor heat use discouraged on the ground?

If you feel that you would need carb heat sitting on the ground, I'd recommend taxing back and waiting for conditions to improve. If you are set on going, usually doing a run-up at the runway before take-off will tell you if you have carb ice or not.

The other answer gave good reasons, sucking in some FOD (foreign object debris), but there are some other things you would want to consider...

Forgetting to push the carb heat back in before takeoff
 - Especially important when taking off from short fields, you want all the power your engine has to offer, as carb heat robs your engine of some power. If you have carb ice, applying carb heat will cause your engine to make even less power (hot air is less dense than cold air). 3/4 of the way down a 1200 foot runway is a bad time to realize the carb heat is still on, because it probably isn't on your takeoff checklist.

Carb heat is not very effective on a cold engine
 - This is a real problem when you are at idle or especially gliding, the airflow over the engine components and the exhaust just doesn't create enough heat to melt the ice in the carb (at least not very quickly). This is why you may be instructed to "clear" the engine periodically during low power operations. This involves adding power and then carb heat to help melt any ice.

That all being said, its not so much a rule as a recommendation. You'll probably find that during your flight training you'll end up leaving the carb heat on while on the ground for short periods. This happens a lot during landing operations when you are instructed to have carb heat on (my instructor taught me mid-field downwind, "Seat Belts, Gear, Fuel Selector, Carb Heat, Mixture, Prop, Power"). You'll end up leaving it on until you've cleared the runway (or set up for a touch-and-go) and are running your "after landing" checklists.


What are the best places to gain the most altitude in a glider?

First, you need practice. Take every opportunity to expand your experience. Theory helps but will never compensate for missing practical experience.
But then you also need to know how thermals form. Let's start low, close to the ground. Two things are important: A chance for the sun to heat the ground (and, consequently, the air above), and an opportunity for that heated air to ascend. Dry ground will heat up better than moist ground, and dark earth better than light sand. If the ground is completely featureless, the air will stay on the ground. So you need to find the trigger which determines where air starts to rise up. Once it does this, more air will be sucked in from the side, and will follow up. That is how a thermal starts.
And that summer gust, which is the horizontal motion of more warm air flowing towards the point where a thermal starts, should indicate to you that now you have a chance to stay up, so now you need to get into your glider. Early in the day the thermals will not go high, so don't be impatient. On the positive side, there are many thermals and a good chance of finding the next one quickly.
Once in the air, look for triggers. One of the easiest is a windward edge of a forest. Warm air is driven towards the forest by the prevailing wind, and the trees will push the air up, kickstarting its ascent. Fly along and a bit leeward of the ridge and you can't miss the thermals there. But even a closed forest is a good source of thermals: The dark trees heat up well and the air between the trees heats up quickly. A small elevation is normally enough to start a thermal. In the mountains, a windward ridge is also an obvious trigger, and it is advisable not to drop below the height of the lowest ridge, as you suddenly might find yourself unable to find any more thermals.
Once higher up the ground features become more and more unimportant. For one, wind is shifting everything sideways, but also now the large-scale vorticity which forms the clouds dominates where the thermals form. Think of cumulus clouds as giant thermal vacuum cleaners which collect the rising air from all around. But not any cumulus cloud: Most promising are the ones which grow, have sharply defined edges and a dark bottom which is bulged upwards towards the center. Flee from the fuzzy ones with a round bottom: They have lost their pulling power and are about to disappear.
Why the bulged-in bottom? THAT is where the heated air goes up and pushes the bottom of the cloud up. But what goes up must come down: In the vicinity of the best clouds you will also find the worst downdrafts. Fly through those quickly and pull up as soon as the downdraft stops.
If you fly cross-country, the most important knowledge is in which direction the wind is blowing. If the wind is strong enough (more than a soft breeze), thermals will line up in wind direction, so you can just leave one straight into the wind (or with the wind) and be sure to hit the next one shortly. This works particularly well if there are no clouds to follow (blue thermals). Just remember where exactly that one-before-last thermal was and fly off in exactly the opposite direction. When that brings you too far off the planned course, cross the valley of downdrafts orthogonal to the wind direction until you arrive in the next lineup of thermals.
Now to how to circle properly. A glider will fly at its minimum sink speed when induced drag is three quarters of total drag - given the high aspect ratio of gliders this means at a really high lift coefficient. Close to stall. Therefore, it is most important to learn how the glider warns you that you are about to stall. Also, some gliders will happily let you fly in a stalled condition (the Discus is a prime example) with really poor sink speed but without loss of control. Go up to maybe 1000 m and then stall the glider slowly. Learn how that feels. Then continue with circles. Stall the glider again. At some point you will feel how the stick forces lighten (that is when flow separation starts on the ailerons!) and you will learn to fly just a bit faster than that. Similarly, the stalled Discus has really soft and mushy controls - fly faster until the controls feel stiff again!
Since circling with more than 45° of bank is rather stressful, fly between 30° and 45° of bank angle. You need to catch the core of the thermal, where the climb speed is highest, and banking more is worth the tradeoff in many cases. Tighten the circle when the climb speed decreases and widen it when speed increases - that helps you to center your circling with the center of the thermal. Learn the hysteresis of your instruments - maybe you need to phase-shift your reaction so you really land in the center of the thermal. For me, I found it easier to remember where the climb speed was best and to shift my next circle in that direction when flying two-seaters - they are too sluggish to do that on-the-fly optimization you can do with the more nimble single seaters.


What is the history of "Joker" and "Bingo" fuel terms?

"Bingo" originated with aircraft carrier operations.  "Bingo" actually means to divert.

The official US Navy definition of "BINGO" is: "An order to proceed and land at the field specified, utilizing a bingo profile. Aircraft is considered
to be in an emergency/fuel critical situation. Bearing, distance, and destination shall be provided."

CV
NATOPS MANUAL

If the aircraft carrier was operating in an area that had a land based alternate airport, it would be called "Bingo Ops". "Bingo Fuel" was the amount of fuel remaining to safely reach the "Bingo Field". The "Bingo Field" was the closest land based airfield which could be used as a backup in case the aircraft was unable to land on the aircraft carrier for any reason. Examples could be a fouled deck due to a disabled aircraft, or unusable arresting gear system.

Other military, and even civilian operators, have since adopted "Bingo Fuel" to mean minimum fuel to safely reach an airport.

My own research shows that there is no definite answer to the origin of Bingo.

"Joker Fuel" is a predetermined amount of fuel in excess of Bingo Fuel.


How to determine the aircraft tail number on a particular flight?

The step-to-step guide:

1. Search for Flight Number:

Get hold of the flight number, such as LH123 or AA789 for instance. This is usually found on your ticket, baggage tag or some email.
Enter it on a site such as www.flightradar24.com or www.planefinder.net.
Note down the registration (such as N1234A or D-ABYT) for the flight on the day your are interested in.

2. Search for this Registration:

Try entering it on for instance www.planespotters.net which is often considered a reliable source for aircraft data.
You should be able to get the aircraft history:

First flight and delivery dates (and hence aircraft age)
Previous operators and registrations.
MSN (manufacturer serial number)


Does the nose-up attitude of a jet make it more difficult to land than a turboprop?

You're asking, I think, two questions. The first in the title is very general; the second in the text relates to control as affected by aircraft pitch on the approach. The answers to both are going to be somewhat opinion based as well as depending on which turboprops and which jets you're talking about.

My thoughts are based on the following turboprops: King Air A90, Swearingen SA-226 and 227, Fokker F-27; and on the following jets: Cessna Citation 500, Boeing 727-100, and Boeing 747-100/200.

In my opinion, there is no general practical difference in the difficulty or ease of approaches and landings based on whether you're in a turboprop or a jet or what your pitch angle on the approach is. Some might say that a nose down attitude is going to give you better visibility. However, I never found that lack of visibility over the nose was a problem.

There are differences in the characteristics of turboprops and jets that make the one or the other the better approach and landing vehicle in certain circumstances. For example, if you need a quick descent, you can flatten out the pitch of a turboprop and get a lot of drag, more if you move into beta. For jets, the engines are always going to be producing some forward thrust (although I seem to remember the DC-8 allowed idle reverse in flight).

If you have a crosswind, the heavier the aircraft and the higher the landing speed, the easier it will be to handle the cross wind, and transport category jets in general are heavier than turboprops. Also, in a crosswind, a high wing is considered a liability, and there are a lot of high wing turboprops.

I guess what I'm saying is that individual aircraft and circumstances outweigh differences between turboprops and jets insofar as approach and landing is concerned.

The hardest and easiest aircraft I flew insofar as getting a good touchdown were both jets: the hardest being the 727-100 and easiest the 747.

The most flexible insofar as the approach was concerned were the SA-226/227. You could fly the approach clean at near-jet speeds and then slow down very quickly on short final. KSFO controllers back in the 1980s used to appreciate our ability to fit in. Or they could bring us in on a close-in downwind and then have us dump it for a well-timed turn to base and then a very short final.

---------- Edit for additional information

@JanHudec pointed out that turboprops have a faster response to power changes than jets. That's true, though in day to day flying, you plan for what you have. Obviously, though, in an emergency situation that required additional power, the turboprop would enjoy the advantage.

The difference in response to adding power is not as great as it used to be. As I remember, when the 727 first came out, there were a couple of incidences of 727s touching down slightly short of the runway because of the time required for the engines to spool up. The figure that sticks in my mind is that for those first engines, the time from full idle to full power was 7 seconds. Boeing fixed the problem by putting in a flight idle and a ground idle. The flight idle kept the engines spooled significantly higher than the ground idle. That involved no change to where you placed the thrust levers. You brought them all the way back. If you were still in the air, that wouldn't spool the engines all the way to full idle.

The 747 engines reacted very quickly, much more so than the 727 even with the flight idle setting. I remember two instances in the 747 in heavy gusting crosswinds where I used a lot of power at the last moment. In the 727 those touchdowns might have been a lot harder? In a turboprop maybe a little less hard?


What is the En-Route Information Display system (ERIDS) used for?

Just visited a facility and learned what this is.

ERIDS provides digital access to static documents like standard procedures and things of that nature. ERIDS provides easier access to these documents than would otherwise be possible. ERIDS also provides a way (not the only way) to access NOTAMs or PIREPS or send PIREPS. I know controllers have other ways to access this information; I am not sure about other personnel. Having multiple ways to access or send this information is helpful to controllers as there may be multiple controllers in a sector and they may need to both access these services.

Essentially, ERIDS is just an informational system that is easy to access in an air route traffic control facility.


Is it true that airlines won't let pilots drink diet soda?

I've never gotten anything to this effect from my airline nor pilot union, and they'd better start stocking cans of unsweetened Snapple if they were to push this, because I don't like coffee & I most certainly don't want to be drinking lots of sugary sodas to get my caffeine fix in the morning!


It looks like its an extension of Class C Airspace from a class E3 announcement,

  ...Class E3 airspace areas are designated as arrival extensions to a
  Class C surface area. Class E arrival extensions are primarily
  designated to provide additional controlled airspace ancillary to a
  surface area to protect instrument operations for the primary airport,
  without imposing additional communications burdens on airspace users.


Many pilots prefer to use their headset boom mic or hand mic instead of the dedicated interphone handset for PA announcements.

I don't know why, but I know from personal experience that the dedicated interphone handset has much better PA readability.


Who can request a check on an engine before boarding/takeoff?

I guess this will vary from airport and scenarios. Say if you are in a small Cessna on a little grass-strip: They will most likely always listen to you. However, In a passenger jet, on a busy airport: Things fast get a little more complicated. It is very expensive for an airliner to hold a plane, and even more to ground it. And it affects more people than it would with the Cessna scenario.

If you tell, say the flight attendant while the plane is rolling down the taxiway that you hear abnormal sounds: They will likely misinterpret you as nervous and will most likely ignore it. But if you can somehow socially convince them: It is still the captain that makes the end decision about turning around.

I don't know if this has actually happened before other than in the article mentioned in the question.

If there is something wrong about the plane: The captain will likely know well before you do. The engines have so many sensors and fail-safes that the captain will likely have the fault displayed in the cockpit before you even notice something unusual, and he will probably make the decision before you even reach a flight attendant.


What requirements do A&Ps (AMT) have to work on avionics?

An A&P may install avionics per an STC or replace a component, but they may not "repair" avionics in the general sense (solder the circuit board). FAR 65.81 specifically prohibits the mechanic from performing “any repair to, or alteration of, instruments.” It takes a FAA Part 145 certified repair station to work on instruments or avionics.  (Remember that autopilots and other “electronic devices for automatically controlling an aircraft in flight”are instruments by definition.) Appendix A to Part 43 defines the calibration and repair of instruments (including autopilots) as an appliance major repair.

Theoretically an A&P could do repairs if he met all requirements for a part 145 repair station but it is highly unlikely it would ever happen.

The repair station or A&P may re-install the part, fill out the maintenance log, and return the aircraft to service. If the A&P re-installs the unit, the reg's say he must have up to date installation manuals, and it specifically requires that “if special equipment or test apparatus is recommended by the manufacturer involved, he must use that equipment or apparatus or its equivalent acceptable to the administrator” to verify system performance (Section 43.13 (a)).

Title 47 of the Code of Federal Regulations, Telecommunication Commission, Part 87—Aviation Services, states that a commercial radio operator license is required to repair and maintain all aircraft stations and aeronautical ground stations (including hand-carried portable units) used to communicate with aircraft.

In the United States, neither the FAA or FCC provide a "Avionics Technician" license or equivalent as the military or other parts of the world do. No certification or license is needed to work for a "repair station".

The FAA is always revising rules and regulations such as promoting ADS-B and   no-longer requiring a STC to promote safety.


How precisely are airspace borders defined?

The boundaries are defined more precisely than the chart can show. What you see on the chart is a visual representation of the text published in JO 7400.9Z (or the most recent version of it):

  AWP AZ C Tucson, Davis-Monthan AFB, AZ
  Tucson, Davis-Monthan AFB, AZ
  (lat. 32°09'59"N., long. 110°52'59"W.)
  Tucson International Airport,
  AZ  (lat. 32°06'58"N., long. 110°56'28"W.)

  That airspace extending
  upward from the surface to and including 6,600 feet MSL within a
  5-mile radius of the Davis-Monthan AFB to the points where the 5-mile
  arc joins a 5-mile arc from the Tucson International Airport, AZ,
  Class C airspace area, and that airspace extending upward from 4,200
  feet MSL to 6,600 feet MSL within a 10-mile radius of Davis-Monthan
  AFB to the points where the 10-mile arc joins a 10-mile arc from the
  Tucson International Airport Class C airspace area.

So in theory, if you're at 5 miles and 1 foot from that lat/long point then you're outside the class C's inner area. But the chart has to show that information in a way that's usable for practical purposes, which means that there has to be a visible line on the chart and that line has thickness. It looks to me like the airspace boundary lines on the chart are roughly 0.25nm or about 1500ft thick, and I have no idea where the boundary really lies on it. You simply have to consider that as a 'margin of error' in this case and plan accordingly. If in doubt, definitely contact ATC.

As for getting in trouble, 1500ft is probably too close for comfort for a manned aircraft, and ATC reacts on what they see on their radar, not what you see on your GPS. It's an interesting aspect of this question that you can probably be more precise with a UAV than a manned aircraft, and 1500ft might seem like more than enough buffer for you. But again, if you have any doubts or questions I would ask ATC directly.


Please forgive me for asking if you are a "flat earth truther".  We sometimes get those numpties passing by trying to justify their theories (especially the one about Antarctica being a ringed ice wall with the military guarding it to make sure no-one learns the secret).

There have been many flights over the geographic South Pole, the first documented one being in 1935 by Lincoln Ellsworth and Herbert Hollick-Kenyon.  See also the first flight over Antarctica.

Pan Am flight 50, using a Boeing 747SP, also flew over both poles.

No scheduled commercial flights over fly the South Pole since there are no great circle routes in use which do so.

Flights from New Zealand to South Africa would fly over Antarctica but no airline currently flies that route.

As to problems with the compass, modern aircraft have no problems since the primary navigation source is GPS.  If you were using a compass only, as you got close to the magnetic South pole (remember, this is not even in Antarctica), the compass would become increasingly unreliable.  Simply maintain a straight course though, over the pole, and the compass will become increasingly reliable.  However, navigating over the magnetic poles using only a compass is the preserve of explorers and the fool-hardy.

This document contains more technical detail regarding navigation.  It talks mainly about the North magnetic pole but is applicable to both.

A couple of other considerations when asking about commercial flights is the need for ETOPS certification and the need to carry special survival equipment when flying south of latitude 72 degrees which is very considerable and would require the removal of revenue seats to carry it.

There is a big difference between the nearest suitable diversion airport flying over the Arctic and flying over the Antarctic.


What safety rule replaced the now-rescinded two-person rule (after Germanwings 9525)?

The French accident investigation board, Bureau d'Enquêtes et d'Analyses pour la sécurité de l'aviation civile (BEA), investigated this incident. The report was completed in March 2016. Among the recommendations for EASA was better medical and psychological monitoring by the aero medical examiners. Explicitly not recommended was the already mentioned practice of the two person rule, which leads to the security door being open too many times.

An aero medical examiner recommended that the pilot should have been committed to a mental facility two weeks before the incident. This fact only surfaced during the investigation. So his mental state was detected but because of lax institutional rules, nothing happened. The report can be found at bea.aero.


An airship pilot has three ways of adjusting lift:

Every lighter-than-air vehicle needs some ballast to adjust its weight. This could be sand, but mostly water is used.
A blimp is only partially filled with helium. The envelope is held taut by filling a bag inside with air, called a ballonet. If you press a little more air in this bag, the overall density of the gasses in the envelope goes up, while the volume stays practically constant. This allows for fine adjustment. Forward and aft ballonets even allow for trimming the pitch attitude.
When the airship moves, the air does provide a little dynamic lift or downforce, depending on pitch attitude and elevator deflection. This is a little tricky, because airships are not stable, and a pitch-up command will lead to altitude loss below a critical speed.

The ballonets in this cutaway drawing of a Goodyear blimp are numbered 2 and 4.

On a calm day, the biggest disturbance is actually the sun. If the envelope is exposed to direct sunlight, it will heat up and the gas within will be heated as well, causing the blimp to rise. If the sun is covered by a cloud, the gas cools down and loses some lift. On partially cloudy days it is not easy to keep the same altitude!

Another threat is an unstable atmospheric temperature gradient. Glider pilots love this, because it will give them strong thermals, but the gas inside the airship will behave similarly to that bubble of warmer gas which causes thermals. When the airship rises, the gas inside cools less quickly than the surrounding air, and the airship will gain lift when it goes up. It becomes really bad on the way down: Now the gas warms up less quickly as well, and the airship loses lift as it comes down. The airship pilot needs to drop some ballast or create more dynamic lift, or his craft will slam into the ground.

Long-range airships like the LZ-127 used a mixture of hydrocarbon gases as fuel. This mixture (called Blaugas) was balanced to be just as heavy as air and filled some of the gas cells within the envelope. Consumed fuel would be displaced by air, so no lift adjustment was needed on a long trip.


Why are there age limits to becoming a pilot in the armed forces?

Largely for the same reason there is an upper bound on how old you can be to start training as an FAA Air Traffic Controller: Training people is expensive and time-consuming (flight training moreso than most military specialties), and we want to make sure we're going to get a certain number of years where the pilot is operating at peak performance out of that investment.
Combat flying - particularly in fighters - is a young man's game: It is physically demanding, and it's much easier to maintain the kind of physical conditioning required when you're younger.

Pilot contracts are also typically longer than other enlistment contracts (I believe the going term these days is 10 years of active service, after you "earn your wings"): A pilot who enters training at the maximum age (currently 28 for the US Air Force) will be 38-39 upon leaving the service, if they re-enlist for another 9 year contract they will be in their late 40s (when the natural process of aging will likely begin to limit the duties they can perform, particularly for more demanding combat roles).
Conversely if they entered at age 35 they would be 45-46 at the end of their first contract, and may already be limited by the natural effects of aging. They would be well into their 50s if they re-enlist, and while we've had active-duty pilots in their 50s they are by far the exception rather than the rule.


How does a G1000 equipped with a GDC 74 calculate IAS from dynamic pressure?

I'm not sure if it is the same for all G1000 installations, but according to this Integrated Flight Deck Pilot's Guide the flight data logging feature records both IAS in knots and TAS in knots.

Do you have the Pilot's Guide for your aircraft? It would likely indicate the values saved in there as well.


Why so much throttle work on navy fighter during final approach?

The rapid motions you see are normal, are not excessive in magnitude, and the duration is relatively brief.  The constant corrections are a direct result of the precision required to maintain glideslope, coupled with the sensitivity of the carrier’s Fresnel lens Optical Landing System.  (OLS, the orange “meatball” centered between two rows of green datum lights)

Navy pilots are taught to control the angle of attack with pitch, and glideslope with power.  (he is not trying to accelerate when he adds power, he is slowing his rate of descent)
Deviations from glideslope should be fixed immediately with a three part power correction:

If you are low, add power to drive the ball up until it is just starting to crest high above the datums, then reduce the power sharply to stop further upward travel, then reset power to a new position that should be correct…
If you are high, reduce power to lower the ball until it is centered between the datums, (never allow it to go low!) add a good handful of power to catch it in the middle, then reset power to a new position that should be correct…

The issue that you can never truly find that sweet spot where you can just leave the power set and ride it out.  There are just too many variables, and the ball is very sensitive.  So, one three part power correction leads to another three part power correction, and so on and so forth.  The reality then is what you see; almost constant throttle jockeying in order to control the ball as best you can.
Fine control requires much more rapid corrections.  Think of it this way, if I asked you to ride a bicycle along a painted white stripe 24” wide you could probably do so quite smoothly.  However, if I asked you to strictly follow a line merely the width of the 4" painted stripe along the side of the road, your handlebar movements would be much more rapid as you made corrections to attempt to avoid straying from this thinner line.  Your bike might follow a more precise path, but you would be a bit more jerky in keeping it there.
For comparison, probably one of the more precise optical glideslopes available to civilian pilots is the 4 light PAPI.  (“P” for precision…)  This pales, however, compared to the sensitivity and precision of the Navy’s OLS.
With PAPI the white light fades slowly into red, and even when the colors are distinct the incentive for immediate correction is not as urgent.  If you have three red lights and one white, so what?  You are a little bit low…  Check your VSI, maybe squeak a little more power on, but if you are assured of making the runway your focus is probably on being smooth.  Nobody is watching, nobody really cares that you are a little bit low, and you have more time to correct it.
It is different on a Navy carrier.  You have 15 to 18 seconds from the time you roll wings level until you touch down.  If you are high or low at the start you need to fix it.  You need to fix it NOW.  If you carry that trend for more than a couple seconds people will start talking to you on the radio offering not so friendly “suggestions”.  There is a team of a half dozen Landing Signal Officers (LSOs) standing at the back of the ship watching and recording your every move.  Their first job is to keep you from hitting the ramp, their second job is to get you aboard on the first pass, their third job is to document every deviation (in short hand) for pilot trend analysis and determination of a landing grade that will rank you against your peers.
Video of every approach is broadcast live on closed circuit television all around the ship.  Your squadron commander, your peers, the airboss, captain of the ship, and a host of other random personnel on the ship are all watching you in real time. The LSOs will send you around with a “wave off” if they don’t like how you are responding to deviations, and your landing grades and reputation will suffer.
There is pressure, therefore the incentive to make immediate corrections is strong.  The ball moves noticeably to indicate the slightest deviation from glideslope, so the pilot is going to move the throttle just as rapidly as needed to keep that ball smack dab in the middle where it belongs, and avoid a wave-off or bolter to get aboard the first time.
Worth noting, but this pilot went to full power well before crossing the ramp, so he must have gotten pretty low in close!
Engine spool-up time is not nearly the issue it was in the early days of jet carrier aviation in the 50s and early 60s.  The Navy learned the hard way back then and these days most jets are optimized for acceptable throttle response at approach speeds.
Regarding your final question, the answer is yes.  Navy pilots are even more skilled than Red Bull air race pilots.


Power changes and trim forces. related to position of Center of Mass (CoG), or Center of Pressure?

Your intuition is correct.  Each of the three principle axes of the aircraft originate at the center of gravity.  Therefore, all rotation in either pitch, roll, or yaw occur around the CG.
The center of pressure is a place along the chord where the lifting force acts on the wing.  It is not a pivot point like the CG is.  In fact, an increase or decrease of lift will actually produce a pitching moment around the CG if they are not co-located along the longitudinal axis.  This contributes to the relative stability (or instability) of an aircraft.


Why does a rectangular wing stall first at the root?

The tip vortex (caused by higher pressure air from below the tip moving into the low pressure region on top by rolling around the tip) reduces the effective angle of attack at the tip and keeps the boundary layer attached longer as the stall progresses.  The tip vortex has this effect with any wing shape, but shapes that reduce drag by shrinking the tip vortex will gain less from it, while a wing with less chord will tend to stall at lower AoA -- causing highly tapered wings to stall at the tip first.

I say "gain" because a tip stall is usually considered bad -- it can cause a spin entry, where a root stall with the tips still flying leads to a straight-ahead stall, other factors equal.


Do fighter jets experience a reaction or recoil force upon firing a missile?

No, rocket missiles are recoil-less weapons.

When firing a gun, the charge burns inside the chamber and the generated gasses do not escape before the shell leaves the barrel, so the reaction force is transferred to the body of the gun.

When firing a rocket missile however there is open space behind he missile and the reaction force only accelerates the generated gasses that are ejected off the back and does not affect the launching platform significantly. This is true for missiles launched from tube (like Bazooka, TOW or Hydra 70), off a rail like the wing-tip sidewinders or from free fall like most of the heavier air-launched rockets.

The lack of recoil is an important advantage of rockets. Bazooka can be fired from shoulder while anti-tank gun with comparable explosive charge is heavy device and needs good support to handle the recoil.

On the other hand rockets need more propellant than comparable gun shells, because the generated gasses leaving at high speed carry away a lot of kinetic energy most of which would be available for the shell in a gun.


How fast do the F-35 weapons bay doors open/close during combat ops?

3-4 seconds may lead to a detection, but then again 1-2 seconds could too with a sophisticated radar system. The important thing is that 3-4 seconds is short enough that a detection would be extremely hard to exploit; by the time a missile could be launched the contact would have disappeared.

If by some chance a station managed to get a missile off in that short time-frame it would probably miss. There are 2 types of radar guided missiles:

Semi-Active radar homing: semi-active missiles only have a radar receiver, they home in on a target using radar painted by a ground station or airborne radar. If the targeting radar station loses lock then the missile will go wide
Active radar homing: active missiles have their own radar emitters which get switched on when they get close to their target, so they are no longer relying on the ground station which is much farther away. They still rely on the ground station to get close enough to use it though, so while active missiles have a better chance it's still very unlikely

So shaving a second off that time would give very little benefit. Having a door open longer would be bad though. In the book "Skunk Works" by Ben Rich and Leo Janos (former director of the Lockheed Skunk Works) Major Miles Pound wrote about his experiences in the first Iraq war flying an F117 when a bomb bay door got stuck open after dropping:

  We came in at three in the morning using only eight airplanes and
  needing only two tankers to get us there and back, and took out three
  of the four nuclear reactors and heavily damaged the fourth. Once that
  first bomb hit all hell broke loose. I dropped my bombs, but I
  couldn’t get my bomb-bay door closed. That was as bad as it could get
  because a right angle is like a spotlight to ground radar and
  a bomb-bay door is a perfect right angle. And out of the corner of my
  eye I saw a missile firing up at me. I had one hand on the eject lever
  and the other trying to manually close that stalled bomb bay. As the
  missile closed on me, the door finally did, too, and I watched that
  missile curve harmlessly by me as it lost me in its homing. About an
  hour later I began breathing again.


Is it likely that an aircraft could have been near 10° 08' north at local midnight August 26/27, 2003?

Yes, it is very likely that an aircraft would be near that position/time/date as there are many aircraft that fly overnight flights from North American airports to and from South American airports, between Europe and Africa, and also between Asia and Australia.
For example, Air Canada has daily night fights from a Toronto, Canada to Santiago, Chile and both the outbound flight, and return flight, would often pass each other in that very same area and time. I would often operate those flights and we would chat with the crew of the opposite flight to exchange reports on flight conditions.
There are MANY other airlines with similar north-south routes operating overnight flights all over the world.


Is this calculation for the 'free' climbing speed when flying in a headwind with a gradient correct?

I propose to look at it in a different way. Let's assume a constant airspeed climb.

We have two scenarios: one where there is no headwind gradient, and one with a headwind gradient. We can calculate the achieved climb speed in both scenarios and then compare them to see what the effect of the wind is. By selecting a constant airspeed, the drag is constant in both scenarios so they can be easily compared.

In both scenarios the aircraft will have the same constant thrust, such that the thrust exceeds the drag. The excess thrust is equal to 5% of the weight.

For the purpose this answer, I do not look at calibrated airspeed but only at true airspeed. Basically I neglect effects of changing density with altitude.

Also, the angle of climb (flight path angle $\gamma$) is sufficiently small to be in the linear domain (such that $\cos\gamma \approx1$ and  $\sin\gamma \approx \gamma$)

Scenario 1: climbing in a constant wind field

In the first scenario the aircraft is climbing in a constant wind field. This can be no wind at all, or a constant headwind or a constant tailwind.

For the aircraft to perform a constant airspeed climb in this constant wind field, all forces acting on the aircraft (thrust, drag, lift, weight) need to be in equilibrium.

Thrust = green
Drag = red
Lift = blue
Weight = black

$\frac{dV}{dt} = \frac{T - D - W sin \gamma}{m} = g\left( \frac{T - D}{W}  - \sin \gamma\right) = 0 $

With a thrust excess ($T-D$) of 5% of the weight, the aircraft need to climb at a flight path angle of 0.05 radians which is approximately 2.86 degrees.

$\frac{T - D}{W} = \sin \gamma = 0.05$

The vertical speed $w$ is then equal to:

$w = V\cdot\sin\gamma $

So in the first scenario the aircraft will achieve a climb speed that is equal to 5% of the true airspeed. Taking 60 m/s from your calculation for the airspeed, the aircraft will climb at 3 m/s = 591 ft/min.

Scenario 2: climbing in a wind gradient

In our second scenario, the same aircraft climbs with the same velocity and same thrust setting, but now it encounters a headwind gradient of 10 m/s per 100 meter of climb. This equates to a wind gradient of 0.1/s:

$\tau = \frac{10 \textrm{ m/s} }{100 \textrm {m}} = 0.1 \frac{1}{\textrm{s}}$.

A climb of 3 m/s would result in an effective wind increase of $\tau \cdot w$ = 0.3 m/s2 which is effectively an increase of true airspeed. Therefore, this isn't a constant speed climb anymore.

To make sure the climb is performed at a constant air speed, the aircraft needs to climb faster.

$\frac{dV}{dt} = \frac{T - D - W sin \gamma}{m} = g\left( \frac{T - D}{W}  - \sin \gamma\right) + \tau V \sin \gamma = 0 $

$\sin \gamma =  \frac{g}{g-\tau V}\cdot\frac{T-D}{W}= \frac{9.81}{9.81-0.1\cdot 60}\cdot0.05 = 0.129$

$w=V\sin\gamma =$ 7.72  m/s = 1521  ft/min

In the wind gradient the climb speed of 1521 ft/min is considerably higher than the 591 ft/min achieved in a constant wind field with the same power setting. The difference is a factor of 2.57 which can be attributed to the wind.


Does intake mass-flow rate vary linear proportional with turbine fan speed?

Not linear, because the back side of N1 will influence the flow. Not only that but the flow is non linear with respect to rotation in most axial flow compressors.

Is there a specific engine or cycle that you are wondering about, because that changes the answer to your question?


How does an auto-pilot control altitude changes?

Short answer:  it depends on which mode your flight guidance system is in.  It can be either number 2 or 3, although sometimes even something else entirely.  Whether you're using a target altitude or descent rate, it still all comes down to what mode you're in.  If you're in FPA, the elevator is adjusted to maintain descent slope.  If you're in VS mode, the elevator is adjusted for descent rate.  If you're in FLC/IAS/SPD, the elevator is adjusted for airspeed.  You should reference your pilot's operating handbook as the exact names and engagement methods for these modes varies a little.

When talking about autothrottle and constant speed altitude changes there are two independent inputs to the system, pitch and thrust, and two outputs of the control system, which are vertical speed and airspeed (or flight path angle and airspeed). You either control vertical speed with throttles and airspeed with the elevator, or airspeed with the throttles and vertical speed with the elevator.  It's possible to mix both throttle and elevator for both airspeed and descent rate (as indicated by number 1 and 4 on your list) but every flight guidance system I know of keeps the two separate to avoid confusion.

Advanced flight guidance systems often have three basic altitude change modes: flight level change (FLC), also sometimes called IAS flight guidance, vertical speed mode, and flight path angle mode. There's more on the differences between VS and FLC here.  I believe assume you're talking about the authrottle in airspeed control with the flight guidance in vertical speed mode.

In vertical speed with autothrottle speed control, attitude control and thrust control work somewhat independently .  Your elevator will be set based on the vertical speed control law to target a certain vertical speed, while your throttle will be trimmed based on its own control law to maintain the target airspeed.  So if you need to decrease descent rate but increase airspeed, your throttle will generally increase while your airplane will pitch up.

You mention adjusting to the descent "slope", which would probably refer to flight path angle (FPA) mode. This mode basically tells the autopilot to adjust the elevator so that the flight path is at a certain angle (not the pitch, but the flight path).  This is a common alternative to vertical speed mode, and autothrottle will perform similarly for either mode.  If FPA is available the pilot can select it instead of VS on the guidance panel.  It's less used than VS, and you can read about why you would use one or the other here.

Flight level change (FLC), IAS, or even sometimes called SPD mode, behaves somewhat differently in that the elevator is used to determine your airspeed.  Thrust then determines your vertical speed and usually this is achieved by setting the throttles to climb or idle settings depending on the situation.

Of course, there's lots of what ifs that go into these systems like stall protection, overspeed protection, non-steady-state behavior, autopilot-authrottle interactions, and engine-out behavior.  I won't cover those details here.


In what cases does it make sense to buy a plane before you begin pilot training?

I will mention some considerations that were not mentioned above. First of all, it does make sense to buy a plane for training, and it can save you a lot of money on rent but you need to be aware of what you are doing. The positive side is that airplanes do not depreciate as fast as most assets of their kind (it is not unheard of being able to sell an airplane for practically the same amount as you bought it several years ago). However, consider that:

Usually an airplane you want to train in (something sturdy and easy to control, like a C-150) is not an airplane you would like to fly most of the time (traveling in a 150 is not a lot of fun, now a twin Comanche is a different story...).
Insurance costs for a student pilot (even with various restrictions) can nearly negate the advantage of not having to rent.

So, if you would like to buy an airplane to mostly train (and have some fun occasionally) and then sell and buy a 'travel' (or aerobatic) airplane, it can save you money. It is better to get your private first, however, so you can concentrate on initial training (which is a handful) without worrying about the 'pleasures' of plane ownership.


Is lashing equipment considered part of a ULD?

Normally I would put this as a comment since I retired in 1999, and I don't know what current practice is. However, this is a bit too long for a comment. Also, this is from memory and it's been a long time now, as it's from my experience with load sheet preparation in the late 1980s and the 1990s. If a more recent useful answer appears, I'll simply delete this.

Further, this answer only directly addresses the question's last sentence:

  Listing the additional equipment as Equipment In Compartment (EIC) does not seem to be a possibility.

The airplane does not, of course, care whether the extra lashing weight is tare weight or content weight. What it cares about is the total weight at the ULD position, and that's what the weight & balance calculations (probably done by computer) will use, whether given as one value or two values (tare & content) that have to be added.

Just adding the extra weight to a compartment without specifying where in the compartment it is would effectively put it wherever the compartment centroid was. That would be correct only if the ULD happened to be at that position.

In actual practice it could be argued that just adding to a compartment rather than a position in that compartment would be acceptable in some instances. For example, let's say you're very close to max takeoff weight before the addition, but the c.g. is well within limits. The ULD locations would have been decided by the software (or manually by the loadmaster) to put the c.g. nowhere near the limits. Adding a few pounds of extra lashing might put you over max takeoff, but it's going to make little difference to the c.g.

All of the three cargo carriers I was involved with insofar as weight & balance were concerned simply listed the total weight at a position. No differentiation was made between tare and cargo. Thus the addition of extra lashing was simply added to that positions weight, usually by rerunning the software to get a new solution.

The most common reason I observed for adding extra lashing was that when loading the ULD to a position, they found that one or more of the floor locks to hold the ULD in position were broken. For such cases, the loading manuals specified how many locks could be inoperative and how much extra lashing there had to be. Frankly, that extra weight was often ignored, but it was sometimes accounted for.

I don't have a definitive answer as to whether extra lashing should be added to tare or content. That is irrelevant to the airplane, though I can well imagine that there might be a form somewhere that required such a split. If someone had asked me back when I working which it should be, I would have said that it should be added to the tare for the simple reason that the ULD is there to safely contain the content. If for some reason extra containment weight had to be added to make the ULD safe, that would seem to be tare weight to me.

And I imagine that a customer, who had paid money for a certain amount of weight to be shipped, found out that because of broken parts on the airplane he had to pay more, he would not be happy.

A thorough search of the weight & balance manuals for aircraft might yield additional relevant information. Some such manuals for 747s and 767s can be found at http://terryliittschwager.com/wbmanuals.php


How do I know how to describe my position on the airport when I contact ATC?

There isn't really an official protocol, beyond the conventions everybody uses out of habit.  Just pick the most prominent landmark, building or chart-labeled zone you can find or think of.  The controller knows all of them so as long as it's not something like "next to a light pole", he/she will figure it out, and if not, they'll ask for clarification.

If the airport has an area designated "transient parking" on the airport chart, use that.  If you're on a ramp area close to the entrance to taxiway Alpha, you could say "xxxx on the ramp near Alpha".  If you're on a ramp in the hinterland somewhere near some hangars, pick the nearest building with a business name associated with it, like "xxxx by Standard Aviation...", or "xxxx by the Shell fuel pumps", whatever.  Use common sense and don't overthink it.


Is the A-10's cannon effective against tanks?

Well it depends....
It depends on the tank, where you hit it, what angle you hit it, how far the A-10 was from the tank when it fired, and what kind of ammunition was used.
Wikipedia quotes that a GAU-8/A firing the PGU-14/B depleted uranium API ammunition offers the following armor penetration capability.

Armor penetration of Armor-Piercing Incendiary ammunition, BHN-300 RHA, attack angle 30 degrees from vertical:

76 mm at 300 meters
69 mm at 600 m
64 mm at 800 m
59 mm at 1,000 m
55 mm at 1,220 m

Whether that's a declassified spec with all other known values a secret or a realistic representation is unknown. I'd say it sounds reasonable. Tanks tend to have heavy armor on the front and sides but lighter on the top. Certainly the PGU-14/B could defeat armor on APCs and older generation MBTs. Modern MBTs with advanced composite/reactive armor may be more difficult to crack. While it might not be able to penetrate the chobham hull of an M1A2, it can certainly take out fuel tanks, destroy the engine, etc.
Keep in mind that a GAU-8/A can hammer a 5-mil Circle with 70 such rounds with a 1 second burst, provided the pilot has a steady trigger hand. This also can have a cumulative destructive effect on armor plating.
While the gun can be employed against armor, the preferred method is to attack tanks using standoff weapons like the AGM-65 Maverick missile. Getting close enough to tank columns to use the gun can be hazardous, especially if the group has mobile AAA/SAM escorts.


Would an aircraft with contra-rotating propellers longer than the plane's wingspan be able to fly?

Short answer: This design will probably work, but it will not be very efficient. It can be tweaked into flying, but when you start tweaking, you would continue such that the outcome would look differently.

Now let's look at your questions one by one:

  How feasible is it to use a propellor larger than the wingspan? Is
  there any law of physics that prevent this configuration?

There is no law which forbids such a large propeller. In order to create thrust, you need to accelerate a mass of air backwards. The larger the propeller, the smaller the acceleration needs to be for a given thrust, since a higher mass flow is available. This makes large propellers inherently more efficient, but larger blades are heavier and also produce more friction drag, so the sweet spot is at propellers which are quite a bit smaller than the wings of the aircraft they are attached to.

  What immediate consequences would be seen in the airflow behind such a
  large propellor? Would the wings aft of the flow still be able to
  produce stable lift?

Since the acceleration provided by the propeller to the air mass is small, the wings behind them would fly in almost undisturbed air. The lift will wobble a little over time, because the boundary layer flowing off the propeller blades will produce a cyclic variation in dynamic pressure on the rear wings. This will, however, not impede their general capacity to create lift.

  The blades remain flat when stowed and act as an
  additional lifting surface; but I assume one could position them so
  that their loss of lift doesn't affect the balance of the plane? (Like
  the sketch with them centered)

At slow speed it helps to have more wing area for lift creation. Note how much the fowler flaps of an airliner move backwards to increase not only the wings camber, but also its area. Using two wings flying in formation would allow to give the rear wing a much higher angle of attack and to use the gap between them to refresh the rear wing's boundary layer like it is done in slotted flaps, so in combination their lift would be higher than that of one wing of the same area. The long, narrow propeller blades of this fictional aircraft look too flimsy, however, to be of much use in adding lift: They would break off at a fraction of their potential lift if built with existing materials.

  Without twist, can a propellor still
  provide efficient thrust? Could you reproduce the twist's effect by
  instead varying the length of the blade's chord from root to tip?

Good that you added "efficient"; this changes the answer from a "yes" to a "no". Only with twist would the local angle of attack be close to the optimum, but even without twist, thrust will be possible. Then the goal should be to pitch the whole propeller blade optimized for the outer 30% of its span. The thrust from this will create a strong root bending moment, however, and I doubt again that the slender prop blade will not break off. If you try to create thrust closer to the center, the outer part, which is flying at the highest dynamic pressure, will create substantial drag, requiring lots of torque, and again the propeller will break off, but in a different direction.

  Are there standard equations for calculating thrust and drag of a
  propellor that does not have twist? Or of a propellor in general?

Yes. The first good ones were published by A. Betz and L. Prandtl in 1919, and the latest substantial improvements were added by Larabee. Incidence can be prescribed, and so can be set constant over the whole span. If you can run a copy of Mark Drela's XROTOR, you can try for yourself.


Can longer paths consume less fuel than the (shorter) great circle path?

That depends how you define longer in aviation. As you can look at it geographically or on the clock.

The hard answer is no, the most fuel efficient route is the one that has the aircraft in the air for the shortest amount of time. If you can take advantage of a big tail wind 20 miles south of the geographically shortest route or at a slightly higher altitude you may burn a bit of fuel getting there but on long haul flights you can make up for the burn, and even gain quite a bit by taking advantage of the winds

Similarly headwinds can really kill your efficiency even over short distances.


What is the best method to time your round out or flare in Cessna 172?

The usual cause for flaring too high is that the pilot is looking at the runway in front of the propeller instead of down at the far end of the runway.

Next time you're up with your instructor, have him do the landing, and look at the far end of the runway while using your peripheral vision to judge your height above the surface.

On the next lap, you fly the airplane, and try to get the same sight picture, both in front of you, and in your peripheral vision.


How are bird strikes tested in helicopters?

Do they happen as frequent as planes?

Here is a link to the Federal Aviation Administration's Wildlife Strike database. Here you can search all the recorded wildlife strikes in the USA, and filter them by various things, including Engine Type.

To get a good idea of how many helicopter bird strikes occur in comparison to other aircraft, we can compare how many bird strikes occurred in turboshaft (Engine Type F) engine aircraft to the total number of bird strikes.

From January 1, 1990 to January 1, 2017...

  California
   - There have been 31 turboshaft engine wildlife strikes, accounting for 0.22% out of the total 13,698.

  Texas
   - There have been 46 turboshaft engine wildlife strikes, accounting for 0.30% out of the total 15,520.

  Florida
   - There have been 22 turboshaft engine wildlife strikes, accounting for 0.20% out of the total 11,119.

This data would suggest that roughly 0.25% of all wildlife strikes are on helicopters.

Taking another piece of data from the FAA, we find that the ratio of rotocraft to general aviation aircraft in 2015 is 9,766 to 199,927, meaning that helicopters account for roughly 4.66% of total aircraft.

Combining these two pieces of data, we can see that since 0.25% of all wildlife strikes are on helicopters, but helicopters account for 4.66% of aircraft,  helicopters encounter wildlife strikes at a rate of ~18.64 times less than general aviation aircraft.

(Disclaimer: Data used above is rounded and averaged. This is a ROUGH estimate!)


What was the first commercial scheduled flight to Australia from another continent (except Asia)?

Background
Jumping to Asia then Europe is known as the Kangaroo Route. Excluding that, that leaves us with flights directly to/from the Americas and Africa.
Nonstop to London is still unrealized from Sydney. Although Qantas flew London to Sydney nonstop in 1989, but that was a delivery flight. Flying Perth-London nonstop will begin in 2018 using the Boeing 787. And with the upcoming 777X and A350-900ULR, Sydney-London should be possible. What that media calls a "Kangaroo Route nonstop dream."
(gcmap.com - A330-300 typical range) Range map shows how far Australia is, for context.
Circa August 1957 is when Australia signed an Air Service Agreement with the US to operate across the USA and onto Europe. Thus securing an alternative to the Kangaroo Route. At the time planes were able to reach the West Coast of the US (with many stops) in sea planes such as the Short Solent. Even with the advent of the jet age, the 707 had to make stops in Nadi and Hawaii.
The candidates for the first scheduled non-stops are:
Africa:

On 6 January 1977, the Boeing 747SP made its first scheduled flight between Johannesburg and Sydney. The flight offered in-flight audio entertainment and movies (flysaa.com).

Contiguous US:
Pan Am:

November 4, 1982 – Pan American World Airways inaugurates service from Los Angeles, California, to Sydney, Australia; at 7,487 miles (11,979 km), it is the longest non-stop flight in the world.

Qantas:

[2014] marks thirty years since Qantas began non-stop flights between Sydney, Melbourne and Los Angeles beginning in April 1984. These services were operated by the long-range Boeing 747SP with a flying time of around 16 hours. Today, the flying time is around 13 hours.


How do hot air balloon pilots avoid collisions?

I grew up in a family hot air ballooning business, and while I haven't been involved in a few years, I can answer your question in two words: They don't!
Taking Off
As far as collisions go, the other answers have mostly addressed this: hot air balloons only control vertical movement, so with all the balloons experiencing the same wind, they'll move at approximately the same speed.
When taking off, we always angled the balloon so that the wind would blow from basket to envelope. In a large group, such as at festivals, we would maintain the same practice as much as possible, and have a line of balloons perpendicular to the direction of the wind. Often, this would restrict the space enough that inflating balloons would roll slightly into adjacent ones, but with a competent/strong person on the crown-line (the rope attached to the top of the balloon, used to maintain stability in the event of crosswind), the small gusts which caused localized rolling could be overcome.
In large groups, when a balloon is ready to lift off, the pilot will typically ensure nobody is going to be directly overhead, then apply more heat to lift out quickly. This prevents the basket from catching any of the envelopes of the balloons still on the ground. As mentioned, once in the air, collisions are not really a problem.
EDIT: I believe you can see two balloons on the ground but vertical which are pressed up against each other in the picture you've provided. Try looking near the middle, just to the top left. You can see that the envelopes are harmlessly pushing away from each other while the baskets are still quite far apart.
In The Air
Balloons are huge and move slowly, particularly slowly relative to each other. If two balloons are exactly level and one directly blocks the wind to the other when a gust comes, it's possible for one to suddenly gain speed. I've never seen gusts strong enough or long-lasting enough to create a speed difference of more than a couple miles per hour, so when the balloons do touch, the envelopes gently 'kiss,' then bounce back. This can, at worst, create a slow rocking of the basket.
Now, the last situation, if a pilot is unaware of another balloon directly overhead and starts going up, it could be a problem. However, pilots typically have radios and can communicate with each other if it's necessary. The pilot in the unseen balloon above would start applying heat to try to get out of the way as well as radio some (likely unkind) choice words to the pilot below him.
Landing
This is more of an after-thought, but if a pilot wants to land and another balloon is already there, the pilot will simply stay in the air a little longer to find another landing site.
Competitions
A second after-thought, but I know about 10+ years back there were a couple competitions at festivals where pilots would receive a special ribbon device and a partner-balloon. The device would mark the longest the ribbon had to extend. Each of the pilots would attach one end to their basket, then the duo who stayed the closest to each other would win a prize.
Another type of competition also occurred in which the pairs of pilots would take off about 15-30 minutes apart and the second pilot would have to try to land as close to the landing site of the first one as possible. Sometimes, this meant landing at roughly the same time and in uncomfortable proximity. Safety is always the first concern of a good pilot, though! If a pilot wasn't sure it could be done safely, he or she wouldn't do it!
Summary
As longwinded as this is, the gist of the answer is that balloon-balloon collisions aren't very serious unless the basket is involved. Typically, they move slowly enough to make it easy to avoid unwanted collisions, despite their lack of horizontal control.


Why safe take off weight exceeds the safe landing weight?

Because when taking off you go from 0 vertical speed to a positive rate of climb all by way of the wings (the force on the gear will decrease over time to 0 when airborne). But while landing you will go from negative rate of climb to 0 vertical speed. Most of that will be absorbed by the gear (the force on the gear will spike and then settle to only the weight of the aircraft). After touching down there is also the braking force exerted on the gear which is proportional to the mass of the aircraft.

It is that spike+braking force that the engineers are worried about when calculating max landing weight.


How do you meet pilots looking for passengers?

Aviation, for me, is a lifestyle more than anything.

Some background: I'm still a college student, but I'm going into the Air Force, I am on my school's flight team, I am getting a degree in asto engineering (and astro physics).  Almost everyone I know is involved in aviation or space in one way or another.  We fly around the southwest part of the country all the time, but it's normal.  One weekend I'll fly LA, and another a friend will take us to Vegas.

Have you considered going to flight training, yourself?  If you find a good flight school, you wont only learn to fly yourself, but you will meet other people like you.  And once you become friends with them you can all fly each other after you get your licences.

Honestly, I would be pretty uncomfortable flying with someone I don't know next to me.  For example, If you've ever picked up a hitch-hiker you might know how it's a bit awkward and uncomfortable making small talk with a completely random person.  Now imagine what that would be like in an airplane... a plane that most likely has controls in both (front) seats, and could do serious damage if used improperly.


My initial response is that, if you have a wedge-shaped airfoil on a glider, what sort of spec are you designing to?  Most of the time, gliders are low-subsonic aircraft with airfoils similar to Epplers, Wortmann FX, or 4-series NACAs, not wedges.  I associate wedges with massive flow separation or supersonic flows.  Can you provide a picture of what you're talking about, as well as a discussion of what you're designing to?  Also, are you attempting to produce a 3D analysis of a wing that, at its wing box, has this wedge-shaped airfoil?

That said, my short answer is this: XFLR is a panel-method solver, which means that it cannot deal with flow separation save by approximation.  As a result, shapes such as a wedge, which are quite prone to flow separation by virtue of their shape, are very hard, if not impossible, to analyze with these solvers.  Unfortunately, lower-order solvers (i.e., something short of finite-element or finite-volume methods, such as Fluent, CFX, etc.) bank on using these panel methods or other lower-order fluid flow equations that cannot handle flow separation.

If you want to try to accurately model flow separation, you'll need a higher order CFD solver, which brings with it additional complexity, cost, and headache--and getting accurate drag information is a tricky prospect.  There are some freeware solvers out there, but, by far, the most popular (and widely validated) is OpenFOAM.  This is a command-line program at heart, but there are some GUIs developed for it that you may be able to obtain for free or at a reduced cost, such as SimScale.  Some other packages are discussed here as well, if you'd like to have a look.

That said, what data do you need?  If all you need is a sectional drag coefficient, I would highly recommend a look through Hoerner's Fluid Dynamic Drag (not to be confused with his other text, Fluid Dynamic Lift), a vital reference that contains data from a plethora of experiments done on a multitude of shapes.  In it, he describes the drag force on objects from ellipsoids to cones to cylinders and more, all based on size, aspect, roughness, and Reynold's number.  There is an updated copy available, but I haven't found it online as of yet.


What are the advantages, disadvantages and current state of affairs for text-based ATC?

I'm a newbie pilot, but I wanted to give the obvious example that crossed my mind when I read your question. In the UK GA world we have to, for example, call up to say we're on final approach. Finals can be a pretty busy time for the pilot, and at any kind of busy GA airport you're likely to have something along the lines of the following discussion:
(Note in my example, my airport has an "Information Service" rather than full blown ATC, but nonetheless - the example stands)

Me: "G-AB Finals, Runway 16"
Tower: "G-AB, Runway Occupied"
Me: "Continuing, G-AB"

This is me telling the controller that I'm aware I can't actually land, but I'll continue flying my approach path down towards some kind of decision height - somewhere around 300'. If I hear nothing again, I'll go around.

Tower: "G-AB, Land At Your Discretion"
Me: "Landing, G-AB"

I now continue my landing, except I'm not happy with my approach so I now declare a go around

Me: "G-AB, Going Around"
Tower: "G-AB, Roger"

Remember that all of the above is going on while I'm setting flaps, keeping on the glideslope, watching the runway and maintaining my airspeed.
Now also, imagine the alternative:

Tower: "G-AB, Land At Your Discretion"
Me: "Landing, G-AB"

So I now have clearance to land. I carry on, there's a bit of a crosswind and I'm working hard. I cross the airport boundary and I'm concentrating on the runway.. Unbeknown to me, a small dog/child/whatever has broken loose and is charging across the grass to the runway:

Tower: "G-AB, Go Around, I say again, Go Around"
Me: "Going Around, G-AB"

In less than 2 seconds the danger is gone, and the tower know now that I've understood and acknowledged. Now in no world am I ever going to be looking down at a screen during that moment - even if a message came through and beeped/bonged or whatever - my concentration will be on landing. Now you might argue for a specific "Go Around" call/button or whatever - but how many of those different things will we end up with. I simply can't imagine a situation where I won't need my headset on and radio tuned.
I'm not saying any of this stuff will never come in, but pressing a button to talk and listen is much more favourable to typing or reading something during critical phases of flight. At best, I can imagine it complementing some of the more mundane messages and perhaps Ground Controllers.
An ATIS text system might be nice, and I imagine routing and similar will be useful - but I can't imagine it taking over voice completely. Sometimes you just can't beat talking - there's a reason people still e-mail the line "I'll call you".
Beyond that - during those radio comms every aircraft in the vicinity now knows that G-AB is on Finals. This is incredibly important to GA traffic operating in VFR because pilots work hard to keep a mental picture of whose where - not to the degree the tower does, but if someone is following me but doesn't have visual (Very common - planes are surprisingly hard to spot), or loses visual, they know exactly where I am and what I'm doing.
The aircraft that's just touched the threshold also knows that control are aware the runway is occupied and hasn't just cleared an aircraft to land.


What is this number in the bypass ratio?

It is 9.6:1  not 9:6:1.

9.6 parts air are bypassed for each part that goes through the core.


Do any other nations have an equivalent of the "Air Force One" call sign?

It is all in your link (in the "See Also"), E.g.:

Brazil: https://en.wikipedia.org/wiki/Brazilian_Air_Force_One
France: https://en.wikipedia.org/wiki/Cotam_001
India: https://en.wikipedia.org/wiki/Air_India_One
Japan: https://en.wikipedia.org/wiki/Japanese_Air_Force_One
Vatican: "Shepherd One", or just in Italy "Volo Papale #" (https://en.wikipedia.org/wiki/Air_transports_of_heads_of_state_and_government)

Note: Often it is better to disguise who the airplane is transporting (especially when flying above a lot of different countries), and often the president has not so much power ("nuclear football"), so a hired jet it is enough, no need to communicate home.


Was it ever considered to optimise a jet to normally operate with one engine shut off?

I can think of one example: the Hawker Siddeley Trident 3B.
This had a fourth, small engine buried in the tail, which was only used during takeoff. They did this because it was cheaper than redesigning the aircraft for different engines.

Since the Spey 512 was the last of the Spey line, extra thrust would be difficult to obtain. Instead of attempting to replace the three engines with a completely different type, which would have been difficult with one engine buried in the tail, Hawker Siddeley's engineers decided to add a fourth engine in the tail, the tiny Rolls-Royce RB162 turbojet, fed from its own intake behind a pair of movable doors. The engine added 15% more thrust for takeoff, while adding only 5% more weight, and it would only be used when needed. BEA accepted this design as the Trident 3B, and ordered 26.


Would adding a slat and a slotted flap increase the max CL of a multi element airfoil to 6.5?

The theoretical maximum lift of a cylinder is 4π. At that point the forward and rear stagnation points coalesce on the bottom of the cylinder. Practical solutions use rotating cylinders (Flettner rotor) but will not reach this theoretical limit.

This should illustrate that 6.5 is not outright impossible but the distance between a cylinder and an airfoil is quite large, so this theoretical limit does not apply to airfoils.

Adding a slat and a slotted flap to a regular airfoil will bring you at most to a c$_{l_{max}}$ of 2.8. Now you want to add them to a multi-element foil. Would that be several slats and flaps in sequence? Practical solutions use a single slat and a multi-slotted flap where the deflection angle of the single flap elements increases along the flow path of the air. A typical example would be the airfoil of the Boeing 727 which had a triple slotted flap which could reach a two-dimensional c$_{l_{max}}$ of 4.2 with 60° deflection and rearward movement of the flaps which increased the effective wing area. Note that wing sweep and ailerons reduced the practical maximum lift coefficient of the full aircraft to 3.0 (see plot below, taken from A. M. O. Smith's excellent article High-Lift Aerodynamics).

With modern CFD this could be improved a bit, but then the preference of aircraft builders has been to reduce the number of flap elements while losing only a little of lift.

Another practical limit is the maximum Mach number in the suction peak of all the airfoil elements. Once this reaches 1.58, no lift growth could be observed in experiments. This translates to a maximum for the product of Mach squared and pressure coefficient of -1.0. In other words: You need to fly very slowly in order to achieve high values of c$_{l_{max}}$.

The only practical design I know which reached that magic limit of 6.5 given as the c$_{l_{max}}$ of its wing airfoil is the Antonov An-70. Here this number is valid for the inner wing which is immersed in the prop wash of the mighty Aerosila SV-27 propellers, driven by the 13,240 hp Progress D-27 turboprop engines. By using the flight speed and clean wing chord for the reference parameters, this looks to me a bit like cheating. But the achieved lift is real!

EDIT:

Now that you show the Selig airfoil, it should be obvious that it is a point design for maximum lift and no practical applicability in real aircraft. Neither will it allow a thick spar nor low drag at lower lift coefficients. Adding a slat will help little, because the limiting part is the pressure rise on the main airfoil. The accelerating flow up to a chord of about 20% is meant to increase the area in the c$_p$-plot and the pressure rise aft of this point is a Stratford distribution which maximizes pressure gain without separation. Reduce pressure in the suction peak only a bit and the flow will separate, and lift collapses.


Where can I find the information from the back of a TAC if I don't have a physical copy?

If you are using Fore Flight you can Turn On Legends which will show you the legend information for the map. You may also be able to download the information somewhere else in the application. It will help if you inform us of which app you are using.

In the documents section of Fore Flight there are some other Atlanta area documents. Im not sure what the back of the cart looks like so I'm not sure if any of them are correct but there is the Atlanta FLY chart and the Atlanta Class B diagram.


What is the difference between static and dynamic seals?

Generically speaking:

A static seal is a seal between two surfaces that don't move relative
to each other.
A dynamic seal is a seal between two surfaces that do move relative to
each other.

The amount of allowed leakage depends on the application.


Not according to the authors of The 4 A's of Marketing 1

  Despite impressive technological achievements and great expectations all around, the service’s business performance ultimately proved an abject failure. In the ten years before Verizon finally pulled the plug, Airfone generated only 50 million total calls, a fraction of the calls carried daily by cellular companies. While the Airfone service was heavily used when bad weather caused significant delays, the system’s utilization at other times was extremely low. A typical plane was equipped with as many as 60 phones. From these, the average large jet generated fewer than 100 calls per day in about 16 hours of flying time. As a result, the expensive system, with its heavy load of fixed costs, remained idle well over 99% of the time.

  ...

  While Airfone claimed that some customers’ monthly bills topped out
  at $4,000, there were not nearly enough of them to sustain the service’s sky-high fixed
  costs.

  ...

  Within a few years of the service’s launch, airlines started to remove the expensive phone
  infrastructure from their cabins, since the Airfone cost them more in increased fuel
  consumption (because of the system’s weight) than it generated revenues through their
  revenue sharing arrangement with Verizon.

My emphasis.