Neither of you are necessarily right, but you both have some understanding which is accurate.

Let me reiterate what you have stated, for clarity's sake. The scenario starts with the aircraft flying straight and level. Then the airspeed is reduced by 30 mph through a power reduction while the attitude is held constant. Regardless of what else happens we all recognize that this will result in some type of descent.

You are right in that the airplane has lost "lift" from the lost thrust and will thus descend. Depending on the aircraft and the starting airspeed, you might be right that the  aircraft might respond with an uncommanded attitude pitch down. If that were the case, it would be due to the scenario resulting in an aerodynamic stall. However, even if the aircraft were to stall it would not drop like a stone (that is, with no lift to oppose gravity), but would descend at what would still be a substantial rate of descent while still producing some lift to oppose gravity. Moreover, considering the possible entry speeds and attitudes, a stall would be unlikely in this scenario.

Your friend is right in that, with sufficient airspeed and no aerodynamic stall—both of which depend on the airspeed at which the maneuver was started—this scenario will result in a descent. It would be accurate to call this a powered descent. Depending on what he means by it, your friend may not be quite right to think that any "new" lift would be produced by the sinking motion itself, but this might be a difference of semantics. Let's explore this further.

Let's consider a Cessna 172 cruising straight and level at 110 mph. We then reduce the power to maintain 80 mph and hold the pitch attitude exactly where we started. In this scenario we have transitioned from cruise speed to something closer to the aircraft's best rate of climb speed. This means that we have transitioned from a high speed, high drag region of flight to a lower speed, lower drag region of flight. At the same time, by holding the aircraft's pitch attitude constant, we have changed from a low angle of attack, low coefficient of lift region of flight to a high angle of attack, high coefficient of lift region of flight. This increase in angle of attack is due to the new angle of the relative wind introduced by the aircraft's descent. The overall amount of lift doesn't change, but the way the lift is created does change. As the speed is reduced the wing's ability to create lift (expressed by the coefficient of lift) increases with the increase in angle of attack. Thus the lift doesn't change, but the lift is now due more to the angle of attack than the airspeed. If this is what your friend means by "new" lift introduced by the sinking motion, then he is right.

However, this "new" lift must be understood to be due to the angle of attack change, not an increase in net speed (kinetic energy). The lift isn't actually changing, merely the way in which it is created—angle of attack as opposed to speed. However, if the scenario were different and we allowed the aircraft to pitch down as we reduced power, the aircraft would pitch down to maintain about 110 mph, and the wing's coefficient of lift would change very little as the airspeed and angle of attack remained relatively constant.


How to distinguish the induced drag of a lift-producing wing from its pressure drag?

There are multiple ways to decompose lift and drag forces, and they are unfortunately not compatible with each other.
If you know the flow field (for example because you ran a CFD simulation), then to compute lift and drag, you need to integrate:

pressure forces (i.e. local pressure times surface normal, over area)
viscous forces (local viscous stress times shear direction, over area) shear stress is tangential to the local surface, but because not all surfaces are tangential to the flight direction, this influences both lift and drag (though usually a lot more to drag).

That gives you two force vectors, and after you added them up, you can then decompose them into one component which is parallel to the inflow direction (drag), and one which is normal to it (lift). (let's forget spanwise forces for now...).
Looking at drag, you can then of course see which part comes from the pressure forces and which comes from the viscous forces.
Next, induced drag: This is actually a somewhat theoretical definition, and most people today speak about "lift-dependent" drag. This means: How much more drag is the airfoil producing because it produces lift? Assuming an uncambered airfoil, the lowest drag is at AoA=0°, when lift is also zero, so all additional drag we're getting at AoA=15° is lift-dependent.
Assuming a cambered airfoil, the lowest drag is actually not at zero lift, and also not at AoA=0°, so at lowest drag, it's actually producing some lift -- so ... negative lift-dependent drag! Just look at these drag polars:

Does that mean we have negative induced drag? Our definition is already becoming difficult to use. So let's keep the airfoil uncambered for now, meaning that the lowest drag is also at AoA=0, where we produce no lift.
So, under these circumstances, what happens to drag when we increase AoA? Of course, pressure on the upper side of the wing reduces, and it increases on the lower side. This means we're getting a pressure force which is pointing mostly upwards (lift) but also somewhat backwards (drag). But we're accelerating the flow on the upper side, which increases friction there. We're decelerating on the lower side, but that effect is a bit smaller. This means we're getting some additional friction drag. But that's not all! Because of the additional friction on the upper side, the boundary layer grows faster than it would otherwise, changing the streamlines, which in turn changes the pressure distribution, and causes additional pressure drag. This means: If we switched friction off now, we'd actually reduce pressure drag, too!
So, really, we can't point at the change in pressure drag and call it induced drag.
Now, if we make some more simplifying assumptions -- the kind that people used to make all the time when they were still using pencil and paper to design airplanes -- that's when things finally start to add up.
This means we're assuming simple potential flow, and maybe we're adding some estimate of viscous drag based on flight speed and surface area, which is not affected by pressure distribution. In that case, we would have no pressure drag on our symmetric airfoil at AoA=0°, and all the pressure drag we're getting at AoA=15° is purely because the pressure on the airoil is pushing normal to the surface, the upper side is also facing backwards to some extent, because it's at incidence to the flow. Now, all the pressure drag is indeed due to lift, and viscous drag is not affected by lift.
So, until now I was talking about "lift-dependent" drag. But what about "induced" drag? Even the Wikipedia article on induced drag doesn't make a difference between lift-dependent and induced drag, so how big can it be? Fairly large, actually. The most common definition for induced drag is the drag generated because the wing produces trailing vortices. So all the kinetic energy in the wing-tip vortices (but also in the vortex sheet behind the wing wherever the lift is changing in spanwise direction) needs to come from somewhere, and that's called induced drag. At least in simplified physics, that is indeed completely pressure drag -- but it does not necessarily explain all pressure drag. Imagine for example an infinite wing. No change in lift distribution, no trailing vortices, but it must have some pressure drag! Mathematically, this can be solved by assuming that when the wing accelerated or increased AoA, it generated a parallel vortex which it left behind, and keeps feeding via two imaginary wing-tip vortices at infinity. But if you measure a 2D profile in a wind tunnel or simulate one with modern CFD methods, the lift-dependent part of drag is much larger than that, because the theoretical induced drag is pretty small next to all the real effects which happen on top of it.
Now, if you take one more step towards reality, and include cambered airfoils, viscosity, boundary layer displacement, and if you're going fast enough also compression shocks (which produce "wave drag", which another factor influencing viscous and pressure drag...) -- that's when "induced drag" becomes fairly theoretical.
So why on earth does anyone still use it? Precisely because it is simple to compute in simple physics models, where you ignore a lot of real effects. That's when it still does tell you what the lowest achievable lift-dependent drag for your wing shape would be, if all those nasty interactions between pressure field and boundary layer, separations, shock waves and other complications did not exist. This means: Induced drag is a useful construct to explain why lift always produces drag, why long slender wings can be more efficient at producing lift, and how much more efficient. But in a real flow, there's not really a way to extract it separately.
Footnote: Of course there are methods to at least approximately extract the different drag components. The best-known tool to do this is Onera's FFD tool (which only few people outside Onera get to use...). I did not find the original paper quickly, but here is the extension to unsteady flow. You can see the math becomes pretty complicated very quickly. You can also see that they provide a lot of drag components, but a closer look shows that although they include induced drag, and a lot of other components, they're not all adding up to total drag -- that's because there are lots of ways to decompose drag, and most of them don't neatly align.


Why does the headset man not get on the tractor?

The "headset man" is a wing walker, and he is there for a reason - he is not just someone who needs a ride to where the aircraft is being pushed to. Essentially, he is an extra pair of eyes for the tow driver. He needs be able to see everything going on around the aircraft to avoid collisions with other aircraft or stationary objects. This task cannot be performed from within the tow truck since the view from there is relatively limited.


How are brakes cooled on heavy aircraft?

Summary

The order of magnitude of brake energy after a rejected takeoff (RTO) for a very heavy aircraft is 1 GJ, or 100 MJ per wheel brake.

Aircraft brakes are cooled with ambient air, either through passive airflow or (optionally) through forced air ventilation.

Cutaway drawings of A380 wheel and brake (Source)

Energy Dissipation

Takeoff speed for heavy aircraft is about 150 knots or 280 km/h. The maximum speed to reject takeoff ($V_1$) depends on the plane, the load, the wind, and the condition of the runway. Let's assume 150 knots for the sake of a rough energy estimation.

The maximum energy that could be transferred to the brakes is more or less the kinetic energy of the plane at takeoff speed:
$$E_\rm{kinetic} = \frac{1}{2}mv^2 $$

The actual energy dissipation will be increased by

remaining power delivered by engines
tail wind
runway downward slope

and decreased by

airbrakes
reverse thrust
head wind
runway upward slope
drag
tire heat dissipation and tire wear

Neither A380 nor B777 have brakes in the nose gear. (Actually very few heavy aircraft have braked nose wheels. See: Are there any aircraft with a nose wheel braking system?)

Airbus A380

The maximum takeoff weight (MTOW) of the A380 is 575 t, and its main gear has 20 wheels. 16 main wheels have brakes and 4 main wheels do not. (See Why do some A380 main wheels have no brakes?)

$$E_\rm{TO,max} = 0.5\cdot 5.75\cdot 10^5\,\rm{kg}\cdot\left(\frac{280}{3.6}\frac{\rm{m}}{\rm{s}}\right)^2 = 1.7\,\rm{GJ}$$

The approximate maximum dissipated energy per wheel brake unit for an A380 after RTO is
$$E_{\rm{wheel}} = \frac{1}{16} E_\rm{TO,max} = 110\,\rm{MJ} $$

Boeing 777

The MTOW of the heaviest 777 is 352 t, and its main gear has 12 wheels.

$$E_\rm{TO,max} = 0.5\cdot 3.52\cdot 10^5\,\rm{kg}\cdot\left(\frac{280}{3.6}\frac{\rm{m}}{\rm{s}}\right)^2 = 1.1\,\rm{GJ}$$

The approximate maximum dissipated energy per wheel brake unit for a Boeing 777 after RTO is
$$E_{\rm{wheel}} = \frac{1}{12} E_\rm{TO,max} = 89\,\rm{MJ} $$

Active Cooling

Aircraft which are foreseen to take-off and land frequently may be equipped with electric brake cooling fans (BCF) which extract the interior hot air to the exterior. The BCF are used during ground time to shorten the turn-around time.

As an example, the main wheels of an A318 equipped with electric brake cooling fans:

Interestingly, there is a difference between steel and carbon brake disks. Steel disks wear out faster when hot, whereas carbon disks wear out faster when cold. Therefore it is preferable to reduce the cooling of carbon disk brakes to what is required for the following takeoff (see this answer).

Passive Cooling

Many (long range) aircraft have no active brake cooling. Passive cooling is caused by

airstream (induced by wind or aircraft motion),
convection,
thermal conduction,
thermal radiation.

Passive cooling of aircraft brakes follows Newton's law of cooling, which is - in terms of mathematics - an exponential decay (or exponential function with a negative exponent, if you prefer).

It may take many hours of passive cooling to reach the ambient temperature. Also see related question What is the temperature of the brakes after a typical landing?

The source of this graph does not indicate the unit of the x-axis, but minutes seem most plausible. The type of the aircraft under test is also unknown. The information is applicable to a range of Airbus aircraft equipped with carbon disk brakes, from A300 to A380.

External Cooling

External ventilation units exist and may be used whenever necessary. These can be electric, petrol powered,

or supplied by a remote compressor or extractor:


Basically, dihedral effect is that during banking, the 'lower' wing will experience a higher angle of attack compared to the 'higher' wing, and a result, a greater lift. The resulting net force and moment reduces the banking angle, reducing stability.
Consider a wing with a dihedral angle $\Gamma$ with a forward airspeed of $u$. If the sideslip angle is $\beta$, the wind due to sideslip is $u \cdot \sin\beta$. From geometry, the normal velocity induced due to dihedral, $v_{n}$ becomes $u \cdot \sin\beta \cdot \sin\Gamma$.

Image from Stability and Control of Aerospace Vehicles
Note: The notations are different in the figure; but the principle is the same.
For our purposes, we can take the sideslip velocity ($u \cdot \sin\beta$) as $v_{y}$. Now, consider two sections from the wing - one each from the 'lower' and 'higher' sides. The induced velocity is of the same magnitude in both the sides, while the direction differs, as can be seen from the above figure.

Image from people.rit.edu

Image from Stability and Control of Aerospace Vehicles
For small angles, $v_{y}$ is nearly equal to $u \beta$. The induced angle can be given as,
$\Delta \alpha = \frac{v_{n}}{u}$.
From the earlier relations, we have,
$\Delta \alpha_{1} = \beta \cdot \sin\Gamma$, and $\Delta \alpha_{2} = -\beta \cdot \sin\Gamma$.
Because of these induced angles, the lift on the downgoing wing increases by $\Delta L$, while of the other one decreases by $\Delta L$. The net result is that the 'lower' wing experiences an increases lift, causing a rolling moment, which causes the banking angle to reduce.

Image from Stability and Control of Aerospace Vehicles


A Hobbs meter measures the time spent in a general aviation aircraft with the power on.

Planes differ in that time is easier to record than distance. For a given airspeed, the distance covered by the aircraft depends on the wind, altitude, and other factors.

Modern airliners would record the period each engine has run, flight time, cycles (one cycle is one pressurization/depressurization cycle), etc., digitally.

Those records are then used to track the time between overhauls (TBO). Same as with cars.

For small planes, a tach timer is used to record the revolutions the engine has made, this one is used for TBO.

(Source) Image of tach timer.


Why do all commercial aircraft have carpets?

helps prevent slips and falls
contains spills (your spilt soda won't ruin your neighbors bag)
more easily removed and replaced
helps reduce cabin noise


What front is going to form after a cold air mass meets a warm air mass?

Weather awareness certainly is a very important part of pretrip planning before even a short local flight.
While cold air masses usually are of higher density than warmer air, wind direction and pressure play key roles.
What makes it a "front" is movement over the ground one way or the other.  Cold fronts are usually sharply defined because the denser air moves underneath the warm air and pushes it away.  Precipitation can be intense, but short lived, followed by rapid clearing.
If the wind direction is right, such as ahead of a low pressure area (in the northern hemisphere), warm air will advance across the ground.  These fronts ride up over the colder air, sometimes for hundreds of miles.  They bring lowering and thickening clouds, "showery precipitation", and fog before finally moving through.
Warm fronts are notorious for creating freezing rain under the right conditions and must be approached with caution when flying.  Cold fronts primarily carry the risk of severe weather and turbulence.
When cold and warm sit side by side with little movement, or are moving in the same direction (as near the middle of a low), they are said to be occluded.
Another type of front is a "dry line".  Humid air is less dense than dry air of the same temperature.  Dry lines should be watched as they also can produce severe weather and turbulence (as would that second diagram!).
Generally, the cold front and warm air wind directions are more perpendicular to each other.


No. You do not need to create new airways. You stick up to the already existent waypoints or not, if the route flies through a segment of free-route airspace.

Also, the engineering department of the airline studies the route, for instance: computes the MSA (Minimum Safe Altitude) for every point, engine failure and depressurization simulations are done in order to avoid possible hazards in critical points, if the aircraft is ETOPS certified they will decide which alternative airports are available for the route, fuel computations, chart generation for arrival and departure (most of the airlines use their own charts instead of those provided by the ANSP), et cetera.

Each airline has its own policy and the process may vary but fundamentally the procedure done is to make a study of all the parameters that can affect to guarantee safety and efficiency.


Why do airfoils in an airplane's wings have different shape and size along its span?

If the airfoil profile does not change along the span, then we can expect the entire wing to enter a stall condition at the same time. This means the stall break will be sudden and sharp.

If instead we transition between several different airfoil profiles along the span of the wing, we can get different portions of the wing to stall at different airspeeds/angles of attack/load factors, rendering the stall more gradual and furnishing the pilot with warning that the stalling process has begun.

Furthermore, if we profile the wing so the wing root begins to stall first while the wing tip is still flying, then we can reduce the tendency of an incipient stall to roll the plane and also maintain aileron authority and hence roll controllability longer into the stall than if the wingtip and the aileron stalled first.


Does the 787 gust alleviation system make a more comfortable ride or for a more stable aircraft?

Both, but the improved comfort and stability are only side effects.

A gust alleviation system uses trailing edge flaps (ailerons, elevators and sometimes spoilers) to counteract local lift changes caused by flying through up- or downdrafts. The flap is deflected to change the local incidence and camber of the wing in order to reduce the change in lift due to gusts. This helps to lower the collective cyclic loads the structure has to endure over time and allows to use a lighter, less strong structure, or it allows to stretch out the inspection intervals for the same structure.

Since the structure will experience smaller deviations from the average load factor, you, the passenger, will experience a smoother ride in gusty air. In calm air the system will not make any difference.

Also pitch changes are smaller since the flight will be less bouncy and the tail surface lift can be smoothed out over time in the same way. Therefore, a gust alleviation system works similar to artificially enhanced stability.

A major problem is the unavoidable lag in reaction. If the bending moment in the wing spar is measured, a computer has to calculate the appropriate response, has to command changes in hydraulic pressure and flight control surfaces need be moved. By the time the flow around the wing is affected by the flaps, the gust has long passed. Therefore, it needs instruments like laser anemometers to measure the wind ahead of the airplane so the reaction can be timed correctly.

The answer to your last question would primarily be based on opinion, so I leave answering it to you.


What is the purpose of the second wifi network on board (some?) B787 aircraft?

I think it has to do with the use of IPads by mainly the cabin crew, according to this article:

It also helps to identify customers quickly, and can be used to alert other staff of a passenger’s special meal or service requirements.

In order to have to crew communicating to each other via the IPad they need to be connected somehow, so I guess that the network you see is just linked to a locally hosted server such that all the IPads can acces the same data even if a crew member makes a change.


Are taxiways always one-way towards a specific, fixed direction?

At any given moment they are generally one direction as planes cant really turn around like cars but the taxi way its self can typically support traffic in either direction. Airports do have a "flow" to them but it depends on the runway they are using as well as the direction of departure of that runway. If the wind shifts and the approach is taken from the opposite direction the controllers will "turn the field around".

This time-lapse video shows the principal pretty well, the aircraft are pushed out onto the ramp form the jet bridge, nose towards the taxiways. They then head out to the departure end of the runway all following generally the same path. They queue up and depart when cleared. If the wind were to shift around they would do so from the other end of the runway which would reverse the flow (generally speaking) on the field.

You can find the FAA's advice on designing taxi ways here.

At uncontrolled airports the pilot can turn the field around.


Why do many GA aircraft not have a "Both" fuel selector?

A quote from the book of regulations, Chapter 14, part 23, verse 951(b):

(b) Each fuel system must be arranged so that—
    (1) No fuel pump can draw fuel from more than one tank at a time; or
    (2) There are means to prevent introducing air into the system.

On a high wing aircraft satisfying #2 on that list is pretty easy: If you connect both tanks to the "top" of the fuel selector as in a Cessna 172 or similar then as long as you have liquid in at least one tank gravity will ensure there will be liquid at the top of the fuel selector to feed through into the engine:

The design of the system provides a passive "means to prevent introducing air" because gravity is always trying to pull fuel downward out of the wings and to the fuel selector.

On a low-wing aircraft like the Piper in your picture we don't have gravity to help us: There's no natural "head pressure" at the fuel selector (or at least much less than in a high-wing with the tanks mounted well above the valve), so we're relying on the fuel pump to draw fuel through the system.
This means we can no longer guarantee item #2 above: If the fuel selector were in the "Both" position and one tank ran dry the fuel pump is going to happily try to suck air through the line from the empty tank, and that could cause the engine to quit.

It's possible to guarantee item #2 in a low-wing fuel system using float valves that seal the tank outlets when the fuel is below a certain level - an active means to prevent introducing air into the system - but that adds complexity and weight.
Since the aircraft already needs to have a fuel selector valve anyway it's easier to just design the valve in such a way to satisfy item #1 on the list: Make sure the fuel pump can only draw from one tank at a time - i.e. "Don't provide a "Both" position on a low-wing aircraft."


Do I need complex endorsement in each class or type of aircraft?

You only need one complex endorsement under FAA regulations,

  §61.31   Type rating requirements, additional training, and
  authorization requirements.

  (c) Aircraft category, class, and type ratings: Limitations on the
  carriage of persons, or operating for compensation or hire. Unless a
  person holds a category, class, and type rating (if a class and type
  rating is required) that applies to the aircraft, that person may not
  act as pilot in command of an aircraft that is carrying another
  person, or is operated for compensation or hire. That person also may
  not act as pilot in command of that aircraft for compensation or hire.

  (e) Additional training required for operating complex airplanes. (1)
  Except as provided in paragraph (e)(2) of this section, no person may
  act as pilot in command of a complex airplane, unless the person has—

  (i) Received and logged ground and flight training from an authorized
  instructor in a complex airplane, or in a flight simulator or flight
  training device that is representative of a complex airplane, and has
  been found proficient in the operation and systems of the airplane;
  and

  (ii) Received a one-time endorsement in the pilot's logbook from an
  authorized instructor who certifies the person is proficient to
  operate a complex airplane.

In your case a class rating is only required for the "multi" aspect of the DA-42 as the DA-42 has no type rating.

The FAA further more defines complex aircraft as

  Complex airplane means an airplane that has a retractable landing
  gear, flaps, and a controllable pitch propeller, including airplanes
  equipped with an engine control system consisting of a digital
  computer and associated accessories for controlling the engine and
  propeller, such as a full authority digital engine control; or, in the
  case of a seaplane, flaps and a controllable pitch propeller,
  including seaplanes equipped with an engine control system consisting
  of a digital computer and associated accessories for controlling the
  engine and propeller, such as a full authority digital engine control.

No part of this definition stipulates how many engines the aircraft has.


What is the fuel consumption per mile for a full CEO A320?

For some general numbers, you can look at the fuel economy tables on Wikipedia. They tell you an A320 flying a 1000 NM flight at typical payload will burn 3.13 kg/km (11.1 lb/mi) of fuel. For a 2151 NM flight, it will burn 2.91 kg/km (10.3 lb/mi) of fuel.
As already indicated in the comments, the fuel burn depends on the payload (and to some extend of course the route length). To get more realistic values, you can use the Breguet equation as shown in Peter Kämpf's answer. When plugging in different values for the payload and flight range (all at 3t fuel reserves), you get these fuel burns:

Since you asked about fuel consumption per distance, we can just divide by the trip distance and get this:

These numbers are somewhat smaller than the numbers from the Wikipedia table. The difference is likely caused by additional fuel burn for the takeoff and initial climb.


Measurement

Runway conditions are measured using a friction standard: ICAO Circular 329, Runway Surface Condition Assessment, Measurement and Reporting.

Local regulation applies too, e.g. for UK: RA 3272 – Continuous Friction Measuring Equipment.

  Adequate runway friction characteristics are needed for three distinct
  purposes:

  deceleration of the aeroplane after landing or a rejected take-off;
  maintaining directional control during the ground roll on take-off
  or landing, in particular in the presence of cross-wind, asymmetric
  engine power or technical malfunctions;
  wheel spin-up at touchdown.

(Source -- Source also used for most of the technical details in this post)

Continuous Friction Measuring Device / Equipment (CFMD / CFME)

(Source: Team Eagle)

(Source)

Decelerometer, Brakemeter, Dynometer... for snow and ice.

(Source: Sherwin Industries)

Minimum Friction Level (MFL) μ is specified by local air authority. A value less than 0.34 is seen by ICAO as slippery.

Friction is measured for each third of the runway, in a direction parallel to the runway centerline.

(Source)

Reporting

Runway friction coefficient should be measured at least daily and reported via NOTAM if needed. NOTAM codes for friction measurement equipment:

BOW Bowmonk Decelerometer
BRD Brakemeter-Dynometer
ERD Electronic Recording Decelerometer
GRT Griptester
MUM Mark 4 Mu Meter
RFT Runway friction tester
SFH Surface friction tester (high pressure tire)
SFL Surface friction tester (low pressure tire)
SKH Skiddometer (high pressure tire)
SKL Skiddometer (low pressure tire)
TAP Tapley Decelerometer

A contamination terminology is used for a qualitative description of the runway condition. It can be used in complement of the friction coefficient value, or alone when a measure is not possible.

Sample for water on the runway:

DAMP: the surface shows a change of colour due to moisture.
WET: the surface is soaked but there is no standing water.
WATER PATCHES: significant patches of standing water are visible.
FLOODED: extensive standing water is visible.

Other terms exist for snow, ice, etc.

  A runway or portion thereof shall be determined as being slippery when
  wet when the measurements with a CFME + self wetting tyre shows that
  the runway surface friction characteristics are below the minimum
  friction level specified by the State.

NOTAM sample:

NOTAN A1713/11 Chennai Airport ( VOMM ),  India
A1713/11 1111220910/1112231200 EST RWY
RWY 07/25 LIABLE TO BE SLIPPERY WHEN WET.
THE VALUE OF COEFFICIENT OF FRICTION IS BLW
THE NOTIFIED VALUE OF 0.34 FOR RWY 07/25
IN SECTION AS BLW :-
RWY07 BTN 400M AND 650M
RWY25 BTN 300M AND 500M

As commented by @RonBeyer (thanks!), pilots can also provide their own observations about braking conditions to ATC using PIREPS. PIREPS are voluntary reports by pilots to share information with ATC and other pilots. They are valued because they are current and they may be the only information available at small airfields.

ATC and recorded bulletins provide runway conditions to pilots, in addition of NOTAM.

Impact on roll distance

Weather has many impact on operations, but runway contamination particularly impacts landings, due to the loss of braking capacity. Take-off are also impacted, mostly at the beginning of the take-off roll, when the control surfaces are not active. Runway condition is also important to take into account if a take-off has to be rejected.

A degraded runway condition decreases the longitudinal stability and increases the roll distance:

Note: As mentioned by @Yos233, autobrake LOW and MEDIUM have been inverted
(Source)

Thrust reversers are particularly useful when the runway is not dry:

Note: Autobrake LOW and MEDIUM still inverted
(Source)

Pilots will use similar tables to determine if they can land or take-off. A flight management computer can also be fed with the runway condition for roll distance determination..

Aircraft are tested for their ability to cope with different runway conditions:

A340 test on artificially flooded runway (source)

Note that it is possible to land and take-off quite easily on compacted snow -- and, albeit more difficult, on ice -- taking into account the coefficient of friction:

Alton Bay runway (source)

More

Description of Various Friction-Measuring Equipment
Used in Winter Operations (appendix A)


Why do engine cowl lips appear larger and more blunt on the sides than on the top and bottom?

Images of 767 and 777 aircraft that I looked at show pretty uniform lips all the way around. This 757 engine (image below) looks thinner on the sides, which is the opposite of what you have seen.

The shape of the cowl (and lip) is going to depend mostly on the shape of the nacelle. The 757 engine (image above) has engine accessories at the bottom of the engine, which requires a thicker nacelle to cover, which requires a larger radius on the cowl lip to streamline. As discussed in this question, the 737 engines have a unique shape to provide ground clearance, so the accessories are pushed to the sides.


Is it possible for a plane to be over fueled (and over-weight) to take off?

The aircraft you flew on was D-AIUX, a Lufthansa Airbus A320-214. On 10 February it was scheduled to fly from Munich to London, but the flight was cancelled due to the storm:

(flightradar24.com)

If the aircraft was fueled for this flight the day before, it would need:

3.13 kg/km x 944 km = 2.95 t of fuel for the trip
about 1.5 t of reserve fuel

After actually flying the 356 km to Vienna, it would have burned about 1.11 t of fuel, resulting in a total weight of:

42.6 t OEW (Operating Empty Weight)
3.34 t of fuel remaining
+any payload

The MTOW (Maximum TakeOff Weight) is 78 t, which would therefore still leave 32.06 t for payload, but the maximum payload is 19.9 t for the A320. So this cannot be the limiting factor.

It was noted that the runway could limit the takeoff. Your flight departed from runway 29, which is 3500 m long:

(flightradar24.com)

The A320 only needs 2100 m at MTOW for takeoff, so this was also not the limiting factor.

You said "they filled the plane in Munich the day before to give the plane more balast to cope with the storm winds", which is not a procedure I am familiar with. Increasing the aircraft weight will increase its inertia and therefore make it less susceptible to wind gusts. Let us assume they completely filled all fuel tanks in Munich.

The A320 has a fuel capacity of up to 27,200 l. Multiplying that with the density of Jet A-1 (0.804 kg/l at 15°C), gives about 21.87 t. This would make the total weight before payload at Vienna 63.36 t, therefore leaving 14.64 t for payload. Now this is lower than the maximum of 19.9 t. Using standard passenger weights in Winter of 195 lbs = 88.5 kg, this would allow 165 passengers. The A320 exit limit is 195 passengers. It is therefore possible that some passengers had to leave the plane to get below MTOW.


Does GA flying in your own plane count toward a Airline Transport Pilot license?

The video isn't very clear, but most of the numbers it gives are "total time". This is cumulative, so the 1500 hours required for an ATPL includes the 250 hours required to get a CPL, which itself includes the 35-40 hours required to get a PPL plus the 15 hours required to add an instrument rating to your PPL. Also included in there somewhere will be 10 hours to add a multi-engine rating.

All loggable time counts toward the total. It doesn't matter if the aircraft is an airplane, helicopter, gyrocopter,  glider, balloon, powered parachute, etc. However, at least in the US, ultralights cannot be logged because they are legally not "aircraft".

As noted in the video, most aspiring airline pilots get flying jobs as soon as they get their CPL, most commonly as Certificated Flight Instructors. Many schools even guarantee a job as a CFI for students who graduate. Few people can afford tonrent their way to an ATPL, and it just doesn't make sense to use loans to fly when there is a shortage of pilots to take jobs where they can get paid to fly instead.


When were flares first used as IR countermeasures, and by whom?

The document Genesis of Infrared Decoy Flares- The early years from 1950 into the 1970s by Naval Surface Warfare Center has a lot of details about the work done on decoy flares in the initial stages, at least in the US.

According to the report, the first use of IR flares was not as a decoy, but as a tracking device for drones. The T-131 flare was used in this capacity. From the report:

  NOTS, China Lake was involved with infrared target augmentation since 1954. ... The T-131 tracking flare developed at NOTS was the first infrared source for drone use. Six to sixteen of these are needed on the F6F-5K drone to provide a suitable signature.

The first IR flare developed as a countermeasure is the NOTS Model 704, which was developed around 1959. However, the studies on decoys for IR started in the mid fifties, though the concept of using flares came later (the initial concepts were towed decoys). From the report:

  The Hayes Corporation, Birmingham, Alabama initiated infrared countermeasures and radiation suppression studies in 1955. ... There was a need about 1957 to create a decoy device that would simulate the signature of a turbojet engine. Instead of the pyrotechnic decoy flare approach,
  ... proposed an inflatable envelope that absorbs the energy from a self-contained pyrotechnic and re-radiates this energy at a lower temperature approximating that of the heated surfaces of the turbojet engine.

Initial flares (RR-77, probably) were fitted in the B-47 and B-52 bombers, which were deployed through the AN/ALE-14 dispenser around 1960. Though the report has indications that the flares were used in the Vietnam war, there is no data on the exact time and location of the use of flares in combat. However, we can be sure that the IR flares were used in combat in Vietnam. The report says,

  In 1967, Dr. Edwards of Air Development Test Center at Eglin Air Force Base, requested Picatinny Arsenal to improve the ALA-17 flare. The Air Force wanted a quick fix to the poor rise time of the ALA-17 flare. They also required that a single ALA-17 flare would have decoy capability to protect B-52 bombers in Southeast Asia against seekers operating in the 2μm to 3μm and 3μm to 5μm bandpass.

indicating feedback from combat operations. Though I'm sure that the Soviets too were developing IR flares at the same time, not much detail is available about their effort.


How does the ADF null positions find where the NDB is?

Short answer

Do you find the null position, then assume it's 90 degrees from the
beacon?

That's correct. For the antenna pattern shown in the question, the angle between direction of nulls and peaks is 90°. When sensing a null (or a peak) there are two possible and opposite directions for the beacon. This ambiguity has to be removed. This could be done by triangulation, with a second reading of the angle of arrival after the receiver has moved a bit, but in the modern ADF antenna this is not required, a sense antenna is added to the loop antenna to change the radiation pattern (i.e. the sensitivity vs. the azimuth):

Radiation pattern of the loop antenna, and loop + sense antenna system (measured in a horizontal plane)
With the sense antenna, the null is at 180° of the peak, and there is no ambiguity. However the performance of the system is degraded by the sense antenna, thus usually two measures are done, without the sense antenna (for maximum accuracy) and with the sense antenna (for ambiguity removal only). See further down for the details.
The reason we prefer to sense the null direction is the signal received is fading at the larger rate near the null than it is increasing in intensity near the peak. The change being more pronounced near the null, sensing the null is easier and gives a better accuracy.
Electromagnetic waves simply
Contrary to what is often thought, the classical high-level principles behind EM waves, which explain how the loop antenna can work, are quite easy to summarize.
The very common representation of an EM wave:

Electric and magnetic components of an EM wave. Source
A wave propagates in 3D space and its electric and magnetic fields are not dissociable, they are a single electromagnetic field which energy is carried by photons (though according to Richard Feynman, EM sources produce not physical particles or waves, but wave-like “probability amplitudes” that propagate at c in space. QED! Well... let's stick to good ol' photons!).
A NDB transmitter is an electric generator, generating an alternating current in a basic vertical conductor which length is tweaked to make it resonant at the frequency used (it's a dipole antenna). Three laws are then governing what happens:

Ampère-Maxwell's law says 1/ the vertical current creates a circular magnetic field around the antenna (Ampère's initial idea). The field intensity follows the variation of the current, 2/ the same happens with an electric field instead of a current (Maxwell addition).

Faraday's law of induction says a varying magnetic field creates an electric field. This field opposes the magnetic flux which created it according to Lenz's law. Lenz's law is a kind of reaction principle.

So AC current creates a variable magnetic field. The energy of the magnetic field comes from the current in the antenna.
As the magnetic field is variable, using the two laws above alternately, we see when a magnetic field varies a variable electric field is generated. When an electric field varies a variable magnetic field is generated.
The energy of the electric field comes from the magnetic field, as postulated in Lenz's law: The electric field opposes the magnetic field changes, therefore it is a force, aka the back electromotive force (back-emf).
What's great is an actual current (electrons) is required only to generate the initial magnetic field, the subsequent magnetic fields are due to electric fields, not depending on a conductor and/or electrons to expand:

Electric and magnetic fields generated from a point of a vertical antenna in a given direction
From left to right: A current is created in the transmitter antenna. If we focus on any point of the antenna, the local current creates a magnetic field around the point. This field induces now vertical loops of electric field, each loop in turn creates a new magnetic field, and so on.
The two fields, normal to each other, are the two inseparable aspects of the electromagnetic field. They exist at the same time, and the repeating process leads to their propagation as wave. As fields have no mass, they can travel at the speed of light.
This process occurs in 3D space, we see concentric shells of electric field radiating from the whole length of the antenna, and between these shells the magnetic field linking the shells:

Still image of electric and magnetic fields. Source (animation).
The electric field at the top and bottom of the antenna is missing, we can predict a "cone of silence" at the vertical of some radio aids using vertical antennas.
The wave crosses conductors while expanding. A conductor acts as a reception antenna. Depending on the conductor ability to couple more or less strongly with the electric and/or magnetic fields, a given portion of the energy from the fields is converted back into current, by virtue of the same reversible laws.
ADF principle
The ADF receiver uses a small-loop antenna (the circumference is small compared to the wavelength), which principle is to sense the magnetic field of the wave, the antenna is actually a coil.
This loop antenna is unusual in the sense receiving antennas generally couple with the electric field of the wave. However sensing the magnetic field is efficient at lowest frequencies and for direction finding applications.

How is the null position created?   Wouldn't the signal still be
received at that position, how does it become null?

Correct, the signal reaches the antenna with the same mean intensity, regardless of the orientation.
Let's look at an everyday life example: Hearing a sound without seeing the source doesn't prevent us to determine its direction. Unless the sound is coming from straight ahead or straight behind, one ear receives the sound first, the same for any reflection, our brain does the rest. Moreover our ear pinna is not symmetrical, this also allows to separate a front sound from a back sound at the same distance, or one low from one high. This localization is irrespective of the mean intensity of the sounds.
Likewise the loop antenna reacts to the combined result of instantaneous amplitudes at all points of the antenna. According to the law of induction, two points of the loop receiving the signal with a phase difference due to the difference of distance from the transmitter (left side below) will be at a different potential, creating a current in the conductor between these points:

ADF antenna sensing NDB magnetic field (not to scale)
On the other hand (right side), when the loop plane is normal to the direction of the wave, each point of the loop receives the magnetic field with the same intensity, no back-emf is created, no difference of potential is measured, no current circulates, this is a null.

Note the antenna is actually much smaller than the wavelength and the phase difference is very small. But the loop antenna is a coil, it is easy to have multiple turns of wire, each turn "collecting" an additional amount of the magnetic field. However as the increasing impedance cancels partly this gain, a reasonable compromise has to be found.

"LW/SW receiver" with a ferrite coil antenna (a coil which inductance is reinforced by a ferrite rod) must be oriented in the direction of the station to maximize reception.
Rate of variation of gain
We mentioned earlier the radiation pattern of an antenna, which is a representation of its relative gain according to the direction. For the loop antenna:

Radiation pattern of the loop antenna (dotted line for the vertical plane). Source
The gain is provided in decibels, which is the logarithm of the ratio between the intensity in the direction considered, and the intensity in the direction of the maximum. By principle the maximum is 0dB (100%) and other values are negative (less than 100%).
When looking at the indications in green, The dip in received energy (the null) near +/- 90° is narrower than the peak near 0°/180°. This tells us about the rate of variation of the sensitivity:

Signal is maximum at 0°, but varies only by less than 2 dB (1.2x) on a range of 60° around the maximum.

Signal varies by more than 30 dB (31x) for only 30° around the minimum/null.

It means it will be more accurate to determine the direction of the null rather than the direction of the peak (which is the direction of the transmitter). This is the case of many types of antenna: Nulls are more pronounced than maximums.
Loop antenna with sense antenna
There is a problem with the loop antenna: It has a symmetrical radiation pattern, when a null is found, there are still two possible opposite directions for the transmitter. The solution is to use an additional element, the sense antenna, which is an antenna with the same sensitivity regardless of the azimuth. It is said to be omnidirectional and is usually usually coupling with the electric field. The two antennas can be combined in such a way the resulting pattern has a heart shape (cardioid):

Radiation pattern of the loop antenna combined with sense antenna
One lobe of the loop antenna (here in blue) adds with the sense antenna, the other is subtracted from the sense antenna, creating a gain dissymmetry.
The ambiguity isn't possible anymore. The null is now opposite to the maximum, while they where at 90° before adding the sense element. When the null direction has been determined, the NDB direction is the exact opposite.
Back to the audio field, this antenna system is very similar to the sound engineering technique called MS stereo using one mono (mid) and one stereo (sides) microphones, though this technique is valid for only a 180° azimuth range.
The usual procedure to determine the direction is:

First find a null with the sense antenna off, because the sense antenna smooths out the null dip in the radiation pattern. This give the direction with 180° ambiguity.

Do a second but rough measure with the sense antenna on to remove the ambiguity.

Modern ADF antenna
On modern ADF, the antenna doesn't rotate to determine the direction of the NDB. Instead the antenna system is a combination of multiple fixed antennas electronically commutated. By selecting different associations, an appropriate radiation pattern is formed and rotated.
A practical realization:

Source


How to maintain your pitch when looking for other traffic in the pattern?

When starting out as a pilot you are normally overwhelmed by all the tasks you need to do. Most of these tasks become second nature with time and experience. Here are some tips you could try.

Make sure the aircraft is trimmed correctly for the manoeuvre so that you do no need any force on the controls to keep the aircraft straight and level. Sometimes you can create your own turbulence because you did not trim correctly but then fight the controls.

Listen to the air noise. You could easily pick up from the change of air noise if the aircraft is loosing or gaining airspeed. A ten degrees pitch change will cause an airspeed change you will pick up by ear. Remember you are flying VFR so looking outside at the horizon to judge your pitch is very important. Flying the correct power setting and maintaining the correct pitch will help you a lot in flying because the aircraft will settle at a certain speed all by itself.

Maybe schedule your flying lessons when the air is more stable and turbulence is minimum. As you gain experience you will be able to handle the turbulence better.

Also try another instructor. Maybe another instructor might be able to understand your weakness and strengths better and handle the situation differently.

Ask many opinions from other pilots in the area. You will find that there are more than one technique sometimes. Just find the one that works for you.


What is the procedure when an aircraft with an emergency can't land due to a blocked runway?

What's the procedure? The procedure is, be creative to save as many lives as possible!

Really. The procedure is to determine a course of action which will likely result in the best outcome for everyone, utilizing all resources and given all constraints. Period. It is as simple as that.

There are infinitely many scenarios, and one cannot be trained for everything. However, pilots and controllers are trained to remain calm. When we look at the accident report years later, reading the document, we can easily say "if the pilots had done that, people would have been saved...". The important thing is that the people who were responsible at the time had to remain calm enough to look at the big picture instead of focusing on a particular problem, otherwise they can easily overlook a solution.

During training, it is common to throw multiple failures / emergencies together. The purpose is not to train the trainee to react to this exact combination of failure, since that is rather unlikely. Rather, the purpose is to simulate a stressful environment, under which one has to make sound and logical decisions.


Why does the CF6 have a lower bypass ratio than the TF39?

Increasing the bypass actually decreases the thrust. A good example is the CFM56-5B variant (sortable table on Wikipedia). The reason is easy to grasp, the more air bypasses the core, the lower the core's power.

The next question would be how did the TF39 achieve higher bpr and thrust? Through an extra half-fan and extra turbine stage. It will make sense by viewing the cross section drawing and front view below:

(flightglobal.com) CF6 top half, TF39 bottom half.

(wikimedia.org) TF39 front view.

This covers the thrust/bpr and the how, on to the why. The DC-10 (the launch CF6 customer) cruised at a higher Mach number (M0.82-0.88) compared to the Galaxy's M0.77. At high Mach numbers, a lower bpr is more efficient (think turboprop with a 40:1 bpr and a jet) -- speed is the key here.

Other reasons include the airlines' desire to have one fan with easy access, and fewer parts to deal with. Flight summarized it in 1969 as follows:

  General Electric CF6 in -6 form at 40,000 lb thrust for take-oft was the engine specified by American Airlines and United Air Lines in their launching orders for the DC-10-10. Whereas the TF39 has a large two-stage front fan assembly the CF6-6 has an entirely new single-stage fan with a small single-stage booster fan. The change brings down the by-pass ratio from 8.0 to 6.2 and permits the deletion of a stage from the compressor; take-off thrust is reduced from 41,000 lb (TF39) to 39,400 lb (CF6-6) but the cruise thrust/s.f.c. characteristics are improved at higher Mach. Other changes include fan blade containment built-in to the casing; substitution of a gearbox to suit airline requirements; control system adapted to airline practice (idle and reverse added); increased accessibility of fan and gearbox; external piping; and a review of all materials for increased life.

The beefier CF6 you mention -- the CF6-50 -- again increased the airflow reaching the core (which reduces the bypass air) by adding booster stages behind the fan. This is how to get higher thrust with minimal changes.

(flightglobal.com)


Why aren't there direct flights connecting Honolulu, Hawaii and London, UK?

Simply, because no airline has determined the route makes economic sense.

A poll doesn't necessarily translate into a ready market of passengers. Sure, lots of people might check a box on a survey saying they'd like to see such a thing, but does that really translate to thousands of people actually a significant sum of money for the service? Would enough of them travel frequently enough at a high-enough price point to make the service worthwhile? There's no guarantee of "certain profit," and considerable money could be lost investing in such a route if it turns out not to be a success. A few reasons why it might not be a slam dunk:

Some passengers already travel between London and Hawaii, through connecting flights. A non-stop flight might cause more people to fly this route, but it would also cannibalize existing business from the connecting flights, meaning you'd need to get further customers to make up the difference.
LHR-HNL is about 7,200 miles. As you note, this should be within the capabilities of long-range aircraft, but we'd still be talking about a flight on the order of 16 hours. This is quite the distance. Would enough passengers want to travel this long between the cities? To put it another way, are passengers willing to travel that long also willing to endure a bit longer of a journey by making it a connecting flight?
The airline operating the route needs aircraft capable of such long flights. If they don't already operate a suitable aircraft, they need to acquire some and train pilots and mechanics and ground staff, an operation that takes years and hundreds of millions of dollars.
Hawaii is generally considered a leisure destination, and it's generally a fairly expensive one at that. Londoners have access to lots of rather inexpensive flights on low-cost-carriers to beach resorts within at most a few hours flying time. Many are in low cost of living countries where accommodation is fairly cheap. Tenerife, Greece, Southern Spain, Mallorca, Cyprus, and a number of Eastern European destinations are all rather accessible, and operators frequently offer packaged trips. Such destinations may not be exactly the same as all the splendor of Hawaii, but they're much cheaper and don't require 16 hour flights to get there.
Will the route be popular with business travelers? Keeping such a service profitable is far easier if you have a regular stream of business travelers between the two cities, especially if they're willing to pay for premium cabins and last-minute bookings. Ultra-longhaul flights without a large supply of business travelers just don't work.
Landing slots at Heathrow, the most logical place for such a flight due to its connections, are in very short supply and thus quite valuable. This further increases costs.
Ultra-longhaul flights work best when they're connected with an extensive route network, so they can receive feeder passengers from and carry passengers to other connecting flights. That's why they generally serve major airline hubs. Honolulu, because of its location, isn't an ideal high-density hub. Its main links are to other Hawaiian and Pacific islands, along with the US West Coast and East Asia, generally to cities that are already served by direct flights to London. As such, adding such a flight would not be that useful in helping an airline build its network. In addition, if Hawaiian were to operate the route, it would need to develop partnerships with European airlines to build a route network there (so as to facilitate booking, of say, HNL-LHR-CDG), a process that could involve lengthy and expensive negotiations.
Is there significant air cargo demand? A very profitable cargo route may help make up for lower passenger demand, but is there a lot of demand to ship cargo between the two cities? The amount of cargo payload you can take also depends on the aircraft you choose. Some aircraft do have the range to make the flight, but would have payload restrictions, which reduces profitability. Larger aircraft may have more capacity, but may be harder to fill.

Also, according to this forum post, a service was operated in the early 80s (with a fuel stop), and it was rather unpopular and thus unprofitable.

All that said, ultimately, all we can do is speculate. Airlines study potential routes extensively, but they don't release their internal numbers. If one thought it made economic sense, they would introduce the new service.


For simplicity, assume a single-engine plane with a two-blade propeller. Just imagine an aircraft is perfectly level and moving forward through the air. The angle of attack on both blades of the propeller would be the same. Now imagine the plane pitches up a bit. One blade's angle of attack will increase and other will decrease.

(source: AOPA.org)

Within reason, the greater the angle of attack, the greater the thrust generated. So one blade (or, to be more precise, a blade on one side of the aircraft) will generate more thrust than the other.


How to calculate aerodynamic efficiency at minimum power conditions?

At cruise condition, a propeller propulsor can be modeled as: $P=TV$, with constant output power as a function of airspeed. Your objective is to find the cruise condition such that the output power is minimized.

Assuming you know apriori what altitude you want to cruise, then density $\rho$ is determined. At level flight:

$$T=\frac{P}{V}=(C_{D_0}+KC_L^2)\frac{1}{2}\rho V^2S$$

At cruise, weight is equal to lift. At minimum power, we have $\frac{\partial P}{\partial V}=0$:

$$\frac{\partial P}{\partial V}=\frac{3}{2}C_{D_0}\rho V^2S-\frac{KW^2}{\frac{1}{2}\rho SV^2}=0$$

Do some algebra, and we have:

$$3C_{D_0}=KC_L^2=C_{D_i}$$

Therefore, the minimum power condition is not equal to maximum L/D (as an aside, it is equivalent to the condition for maximum rate of climb, which is pretty intuitive).

Now you can find the corresponding $C_L$ and verify whether it's within the valid range of the lift curve. Generally, we want at least 1.3G margin to stall warning or stall buffet. So a 1.4G margin to $C_{L_{max}}$ might not be a bad place to start.


Can I still take the knowledge test with the US government shutdown?

Looks like private testing centers can conduct the tests now.

Full details here, from 22 Sept 2017.

https://www.faa.gov/documentLibrary/media/Order/FAA_Order_8080.6H.pdf


What precautions should be taken when flying near the magnetic poles?

You raise an interesting question, and I assume you refer to flying near the poles using a lightly equipped general aviation aircraft. Airliners or jets usually have inertial navigation equipment that is working autonomously and will not be affected by pole proximity.

Several procedures could be taken in a general aviation aircraft to improve situational awareness:

You need indeed to deslave the HSI from the magnetic slaving transmitter in order to use it as a directional gyro manually slaved (see How does a horizontal situation indicator (HSI) work?). The directional gyro will have to be realigned manually regularly to compensate for precession (astronomical precession is 15°/hour at the pole, to the right at North pole, to the left at South pole).
Don't forget it is still possible to use astronomical navigation if you are in VFR conditions and able to see stars (at night) or the Sun (during day). This will not be very accurate but a precision better than 5 to 10 degrees could be reached without needing a sextant. Computing your location only from star positions is a complex operation, but it is rather easy to find out aircraft true heading thanks to the Sun or major stars relative position from aircraft nose. You could use this heading to manually realign your unslaved HSI/directional gyro.
Regarding GPS, it is strongly advised to check in advance GPS coverage near the pole using RAIM prediction function, either from the onboard GPS or using web servers. This will allow you to check the coverage should be assured according GPS satellite locations relative to your position (an outage is always possible). When flying in such remote locations I always bring with me a portable standalone GPS unit, in addition to panel mounted GPS.
Standard navigation (keeping track of position thanks to heading and clock) of course should be used and near coasts you could cross-check your computed position using landmarks, but above ice caps you will have few or no landmarks.
If you are lucky enough to have an inertial navigation platform on board, your position will be kept rather accurately independently of any other input, with an error of the order of 10 NM after 7 hours of flight.

The main issue you will encounter in a general aviation aircraft flying near the pole is their endurance is often limited, regulatory fuel reserves are higher than usual, airports are few and far apart, alternates may close quickly due to quickly changing weather conditions. This means that when you fly or are ferrying an aircraft in those regions, you could definitely not afford to get lost or not to be sure of your position.


Does Raymer's installed engine equation include the weight of the pylon?

No, it doesn't include the pylon. If you think about it, the engine is installed on the pylon, which is part of the aircraft's fuselage or wing structure and not part of the engine.

You can see what I mean by watching this video of the replacement of an engine on an American Airlines 777.

Raymer's equation does include the nacelle and other auxiliary equipment installed on the engine.


How to find past flight routes between 1977/82 Latin America and the former Soviet Union?

Here are a series of old Aeroflot schedules. In 1977, from Latin America, they flew two scheduled routes

Lima > Havana > Lisbon > Frankfurt > Moscow
Mexico City > Havana > Lisbon > Frankfurt > Moscow

It seems unlikely there were scheduled stops not listed, as if you're including a 1h10m refuelling stop at Lisbon you may as well list them all :-). Note that most of the international flights (perhaps all the long-distance ones?) went into Moscow; there were a few into Leningrad but all European routes.

However, it is possible that Aeroflot provided a charter-type service to collect foreign students (especially if it was some kind of large-scale state-backed scholarship scheme). In which case... the "hopping" route and then to Leningrad (via a fuelling stop somewhere) seems quite plausible, but finding documentation on it forty years later would be incredibly challenging.


Is it a violation to list an alternate airport based on an approach your aircraft is not equipped to execute?

I have not found any LOI's that cover this specifically but a broad interpretation of

  § 91.205 Powered civil aircraft with standard category U.S. airworthiness certificates: Instrument and equipment
  requirements.

  ...

  (d)Instrument flight rules. For IFR flight, the following instruments
  and equipment are required:

  ...

  (2) Two-way radio communication and navigation equipment suitable for
  the route to be flown.

Once can broadly say that if you intend to fly an ILS (alternate or not) 91.205 requires suitable equipment i.e. an ILS receiver and CDI capable of displaying as such.


I don't know, but ...

If you look at the IATA application form you will see there is nowhere for the airline to indicate the code it would like to receive.

I imagine many new airlines might indicate a preference in an accompanying letter (e.g. they would like a code starting with a specific letter)

If you look at the allocated codes you can see that, initially, some attempt was made by IATA to make the two-character codes mnemonic

AA = American Airlines
BA = British Airways
etc

However if JB was already allocated, it is reasonable that the IATA
staff would look for an available code starting with either J or B.
Since the Blue of JetBlue is more distinguishing than the Jet part of the name, the IATA employee may have started with B and noticed that the following were already allocated

B1 Bravo Passenger Solution Pte., Ltd.
B2 Belavia
B3 Bhutan Airlines dba Tashi Air Pvt L
B4 ZanAir Limited
B5 East African Safari Air Express Ltd.

(note I have not checked dates these codes were allocated but the hypothesis seems plausible to me)

The last two are puzzling but perhaps they changed their names (perhaps as part of a takeover, merger or split). Airline codes do get reused. For example, B5 was used by FlightLine before it went out of business.

Then B6 would be the next available code.


Why is there a maximum landing weight limit?

At the instant of touchdown, any vertical kinetic energy the plane possesses must be absorbed by the landing gear, which thereafter must bear the entire weight of the plane. That kinetic energy depends on the sink rate and the plane's weight.

The sink rate ideally will be zero at wheels down in a perfect world, but the gear is designed to accomodate a certain range of sink rates and plane weights via compression of its spring struts and shocks. If either the sink rate or the plane's weight causes the maximum compression range to be exceeded, the suspension will run out of travel and bottom out hard and the resulting shock can damage the attachment points of the gear to the fuselage or the gear itself- or even cause the gear to collapse.

The maximum gross weight at takeoff (full tanks, maximum payload) is set by engine power and wing lift when configured for takeoff and the expectation is that by the time the plane has reached its destination it will have burned off enough fuel to be under the allowable gross weight at landing (which is set by the design of the landing gear as explained above). This means that the plane's designers can minimize the weight of the landing gear by not having to strengthen it enough to routinely accomodate a landing at maximum gross weight at takeoff.

And that, in turn, means that if a fully-loaded plane has to make a quick return to the line for any reason, it must dump fuel first.


As far as I'm aware there's no specific regulation that requires a control tower to be established. FAR 170 and the regs referenced therein set out when an airport becomes eligible for a tower, but nothing requires an eligible field to have a control tower (in fact the FAA won't establish a tower unless someone gives them the land).

That said it would probably be a Bad Ideatm for certain airports to operate without a control tower (Atlanta, Kennedy, O'Hare, LAX...) - in fact those airports are busy enough that they have additional traffic management procedures in place beyond what a control tower can provide.

Control towers exist to improve safety (improve risk) as you alluded to. There are procedures and rules established to allow pilots to self-sequence at untowered fields (you'll find those in section 4-1-9 of the AIM), and they work very well when everyone follows them.
The catch is everybody doesn't follow those procedures - or more accurately they're followed with varying degrees of precision (my personal favorite example of sloppy procedure is when you hear someone say "any traffic in the area please advise" at an uncontrolled field). These procedures also don't cover other movements on the airport surface very well: Some pilots will announce their taxi plan at an uncontrolled field, but there are plenty of pilots who taxi from point A to point B with their head up and their mouth shut so as not to tie up the frequency for aircraft in the air.

As the number of operations increases at an airport the various degrees of precision and adherence to the uncontrolled-field procedures in the AIM  becomes more of an issue, and a control tower may be established by the FAA or the local airport authority to safely and efficiently coordinate aircraft movements.


Why do airfoil's trailing edges point downward?

You are right, the trailing edge does not need to point down. Take symmetric airfoils - here the trailing edge runs parallel to the airfoil chord. Or take reflex airfoils (like the HQ 34 of the SB-13 tailless glider): Here the trailing edge is indeed pointing upwards, and still this aircraft flies.

But to create lift with as little drag as possible, it helps that the trailing edge points slightly down. Why? Because then it will be least in the way of the desired local flow. Lift is created by accelerating air downwards. The wing deflects the air flowing over it, and the trailing edge should reflect this deflection angle.

But - as always - too much is not good: The Eppler 417 airfoil of the SB-7 glider was an extreme layout with too much rear camber. It is said that pilots could still wipe off raindrops near the trailing edge after landing when they had crossed a shower an hour earlier. This means that airflow separated well ahead of the trailing edge on the upper surface, and the raindrops would not be blown away in the separated flow. Flow separation increases drag, and this effect shows that the shape of the Eppler 417 had too much downward camber at the trailing edge.

If the plane is large and heavy, its airfoil's rear camber can be higher - an extreme case is shown below. This is an early supercritical airfoil designed by McDonnell-Douglas, and the highly cambered rear part allows it to integrate very effective Fowler flaps. Flaps help because they allow to change the direction in which the trailing edge is pointing: Low lift coefficients require no flap deflection, or even negative flap angles in gliders, and the higher the lift requirement grows, the more the flaps will be extended, pointing more and more downwards.

The same is true for control surfaces: Depending on the desired lift change, their trailing edge will point up- or downwards. See below for an example where I plotted the pressure distribution for three flap deflections in one graph. Upper and lower surface pressure are shown by color-coded lines, and lower lines belong to the lower surface. Dashed lines show the inviscid pressure, and solid lines the pressure distribution with friction effects added. The wider two lines of the same color are apart, the more lift is created. Note the contour plot below, which follows the color scheme of the pressure plots.

If there are slots to re-energize the flow, extreme trailing edge angles are possible and help to create lots of lift at low speed, which helps airliners to get into small airfields. See below the triple-slotted flaps of the Boeing 727, which was designed for regional traffic from and to small airports.


Aside from the ground clearance thing Crossroads mentioned, the main aerodynamic benefit of gullwings is to achieve a clean 90 degree intersection with the fuselage, which eliminates the need for a big wing root fillet fairing.


Can you fly a light GA airplane into a major hub? What operational considerations are there if you do?

Can you?  Absolutely, and air traffic control will treat you (almost) like any other airplane.  You are supposedly handled on a first-come-first-serve basis (reality is slightly different with different aircraft speeds, etc.).  Do the airlines like it if you slow them down?  No, but it's part of the system and the way that it works.

Very often, there are multiple runways at bigger airports, and sometimes there are even shorter runways that are dedicated for airplanes that don't need to land on the same one as the "big boys".  Even if not, they will work you in.

Now, that being said, very often there is a better option.  As you said, there are usually high fees at the big airports, so landing at a smaller satellite airport can often save you money and save you time because you won't have to taxi as far or sit and wait in line to get out.  An extra 15 minutes by car can be better than an extra 30 minutes while taxiing.

As far as being prepared, it isn't really much different than smaller airports other than the fact that ATC is much busier.  They don't have the time/tolerance to keep repeating instructions to you, and expect you to be "on your game".  When they rattle off taxi instructions like "Cessna N1234, taxi to the ramp via Alpha, Tango, Echo, and Xray. Hold short of runway 23." they expect a quick readback and for you to follow instructions exactly because they need to move on to the next guy.

It will also help everyone out if you don't fly your final approach the way that most people are taught for an entire 10 mile final:  very close to your actual landing speed.  In fact, you are usually landing on a runway that is 4X+ the distance that you need and you can slow down fairly quickly (especially compared to a jet), so if you can fly an extra 20 (or 80) knots as long as possible, it will be greatly appreciated and keep traffic moving.  Make sure that you leave yourself enough time to slow down at the end and above all else, be safe.


Do any newer production aircraft use venturis as a backup vacuum source?

Not as far as I know. Even Vacuum pump systems are quickly becoming a thing of the past. Electric AI's are available and I have seen plenty in use. However with glass cockpits making their way into general aviation AHARS units are becoming more and more common place over traditional vacuum systems. There are even some small drop in units intended to replace traditional vacuum systems like DG's and Attitude Indicators. Venturi vacuums, while simple have down sides like potential icing risks and needing sufficient airflow to function.


How do aviation engineers ensure that the landing gear opens every time, without fail?

The short answer is extensive testing and backup/manual over ride systems. In reality there is not a whole lot that can go wrong, landing gear systems are fairly simple in design.

This varies a bit by airframe but most landing gear systems are pretty much the same. Basically every aircraft out there, from a single engine Piper Retract all the way up through a 747 has some form of manual gear over ride system. You can read about that in this answer here. So basically if the main system fails (and it happens) they have some kind of manual over ride to force the gear down. Granted there can be cases where the manual over ride also does not bring the gear down but you can only be so redundant. Some gear is also held in place positively, in other words there is pressure on the system holding it up so that should the hydrolics fail you dont need the pressure to get the gear down. Often the gear is oriented so that gravity and aerodynamics can deploy it.

Fixed gear is generally not a great idea on anything bigger than a small trainer. Fixed gear adds drag at the cost of a simpler airplane. You can read up on a similar question here.

I dont think lighter gear is something they are looking into to solve the gear deploy issue. Generally speaking you want the gear to fall down in the event of a failure so a little extra weight is not the end of the world.


What are typical stability analysis dampening values?

For the eigenvalues:

The Roll Subsidience should be negative.
The Dutch Roll values should have negative real parts, and they will be complex conjugates unless something is really wrong with your model.
The Spin (spiral) mode should ideally have a negative sign but there is some leeway to it being positive if the modulus is small.
The Longitudinal modes should both have negative real parts, especially the short period mode (the one with the highest frequency, in the 10Hz range where the pilot cannot react in time to damp it)

Assuming the eigenmodes are convergent, the dampening coefficients need to be large enough to kill any oscillation in a reasonable time frame. What is reasonable is often up to the particular design case; for example fast enough to prevent resonance with some structural mode, or far away from the pilot´s natural feedback loop to avoid PIOs .

For a brief primer on stability, see here: https://courses.cit.cornell.edu/mae5070/DynamicStability.pdf


Why do propellers have less theoretical range (i.e. range ignoring impatient passengers wanting to go fast) than jets, despite greater efficiency?

For more background, this question is about the usage of Breguet Range Equation (I find this explanation better suited for this question)

There are many problems with your calculation:

Time unit of speed should be the same as the time unit of SFC. For your first calculation, since you used mph for speed and lb/(hp*h) for SFC, your SFC term shouldn't have 1/3600. For your second calculation, since your speed is fps and your SFC is also in lb/(lbf*s), there's no need to have 1/3600 either.
For both calculations, end result should be the same unit of length. Your first calculation uses mph and the second uses fps, so the the end result would be in miles and feet so not comparable. But since you made the mistake #1 you end with numbers still on the same order of magnitude.
For the propeller case you are using PSFC (Power specific fuel consumption) rather than TSFC (Thrust-specific fuel consumption). Breguet Range Equation requires TSFC to work.

If you look at the Breguet Range Equation you see the only difference between prop case and jet case is TSFC. So to compare relative range differences, you only need to compare TSFC and avoid all other complications.

Take Cruise TSFC from some modern examples:

GE90: 0.545 lb/lbf/h
Europrop TP400: 0.38 lb/lbf/h

(1/0.38)/(1/0.545) - 1 = 43% so with everything else being the same, prop should have about 40% more range than jet.


Is it normal to use only one hand on the yoke while landing?

It is absolutely normal, in fact it's rare for a pilot to have more than one hand on the yoke at any one time as it isn't required. Movies will often show pilots manhandling yokes with two hands, but that's just Hollywood. The only time two hands is required is when extra strength is needed on the controls, for instance a hydraulic failure.
When landing a pilot will have one hand on the yoke (or stick) and one hand on the throttle, as throttle adjustments are needed to maintain the correct glide angle and initiate a go-around if required.


In WW2, were self-sealing fuel tanks really cost-beneficial?

Your description of a self-sealing fuel tank remaining on fire when lit is the exact situation of the sealing mechanism failing. As soon as the tank is punctured, regardless of a fire or not, the rubber in the middle layer will react with the fuel and swell until the hole is reasonably obstructed. This both extinguishes the fire and seals the leak. Consider a case study: in the Pacific theater, Japanese fighter designs did without self sealing tanks for the cost and weight saving benefits. American naval designs such as the Hellcat however, had every possible damage-control system of the day installed everywhere possible to make the planes as rugged as they could. In the end, Japan mainly lost control of their own airspace due to the fact that they simply ran out of materials to build new planes from. The rate at which they lost planes was incredibly high due to both the small .50 caliber rounds' ability to set the unprotected tanks on fire, and the poor training of Japanese pilots towards the end of the war. If you look at statistics, per battle the IJAAF and the IJN lost more planes per squadron and battle group than any other country's air service in the war. In fact, many of the IJAAF's main fighters including the Mistubishi A6M Zero and the Kawasaki Ki-61 Hien were infamous among pilots of both sides of their ability to catch on fire from what should have been inconsequential hits and particularly their inability to stop burning. Another point of interest is the design of the self sealing fuel tank:

This all goes to prove strongly that NO, self sealing fuel tanks are a definite must in combat airplanes, and a very important safety feature in other aircraft types. I'm confused however as to why your question switches from bullets (incendiary?) to flak as anti-aircraft guns such as the Flakvierling88 were not meant to ignite fuel tanks, they were supposed to destroy the whole plane, fuel tanks and all. If you want some more numerical data backing up my position, Wikipedia references many sites that give a bit more data on why self sealing tanks are a must for fighter planes. The Defense Systems Information Analysis Center also provides some interesting information on the design and how they weren't all too much of a cost/weight penalty later in the war. Hope this answers most of what you're asking.
In addition, there is a specific part of the article of my second link I would like to draw attention to:

This simple composition and design, which are inexpensive, lightweight, and easily produced in large volumes, confronts the deceptively complex ballistic dynamics of a bullet perforating a fuel tank.  When a normally oriented bullet pierces a fuel tank, it leaves a small residual hole less than the diameter of the projectile.  But this small hole is just the beginning of the challenge.  The bullet, travelling at 3,000 ft/s, begins to unload its tremendous kinetic energy on the fuel inside.  This unloading generates a high-velocity wave of pressure in the fuel that is reflected back on the wall milliseconds after the bullet tears through.  This pressure wave, known as hydrodynamic ram, blasts a jet of fuel back through the entrance wound.  The bullet, still moving at a high velocity, and now followed by the same pressure wave, begins to tumble as it travels through the fuel.  When it reaches the back wall of the tank, the bullet erupts sideways through the material and leaves an elongated gash that is often torn further by the trailing wake of hydrodynamic ram.
Initial fuel tank prototypes tested by Navy engineers were discouraging failures.  Engineers had not anticipated the challenging dynamics, and often the entire back walls of prototype tanks were blown out by the hydrodynamic pressure wave.  However, these early development tests shed some light on the mechanisms that brought down so many pilots and aircraft during the World War I.  The Navy and rubber company engineers persisted and established remarkably effective design features and manufacturing processes that ultimately saved untold lives not just in World War II but in each of the armed conflicts since then.

This statement strongly backs up the cost/weight penalty not being an issue position, if this clears anything up.


Does the DA-42 automatically lean to clean fouled spark plugs?

Depends on the variant.  Most DA-42s are powered by turbocharged Diesel engines and do not have spark plugs.  And yes the DA-42 uses an automatic run up cycle in order to test the Engine Control Units (ECU).  The test button is depressed and held while the automatic ECU cycle runs on both ECUs for each engine; the pilot simply monitors the engine gauges for signs of abnormalities.

Now the DA-42L is an exception to this rule as it is powered by Lycoming IO-360 gasoline engines.  It makes use of more conventional run-up procedures.


What is the fourth contact for on the Bose A20 headset's mic plug?

This kind of plug has contacts, not pins, that one on the end of the mic plug's the PTT (Push To Talk) contact for a military spec microphone plug.

This helpful page explains it:

The first aircraft radios used carbon-granule microphones almost
identical to microphones used on telephones. However, a second
function was needed on the microphone in the form of a push-button to
key the transmitter and effect a changeover from receive to talk . . .
hence the name push-to-talk or PTT switch. Telephone companies not
only had pretty rugged microphones, they could offer a nifty 3-circuit
plug to go with it. To this day, the terms "tip", "ring" and "sleeve"
coined by the telephone industry are used to identify the three
circuits. The addition of a "ring" connection allowed us to craft a
PTT microphone companion to the already common headset. Being smaller
than a headset plug made it easy to avoid plugging the headset into
the wrong jack and vise-versa.
This particular plug is a mil-spec critter and appears to have yet
another "ring" between the tip and ring connections I've noted . . .
this may or may not be visible on your particular microphone plug . .
. in this particular plug, it's simply a spacer to fill out the shape
an maintain commonality with the dimensions of other style plugs.

When you watch some WWII movies you see pilots touching their mics or boxes close to their neck to talk, that's because the PTT was wired in-line with the headset rather than being on the control column or throttle. The 'tip' was there to enable that, when the PTT was depressed an electrical connection was made between the tip and the sleeve, signalling the radio to switch to talk mode. Note that the movies aren't always right, some airplanes had a PTT button off the headset, but that's just one of many common inaccuracies.
Nowadays the PTT button is often wired on the other side of the plug so that the PTT button goes to the stick or yoke, but the principle is the same, it's just that the connection is made farther up the line.
The plug on your headset is a slightly older design with a spacer between the tip and the ring to ensure the two stay separate electrically. It isn't an actual contact because it doesn't go anywhere.


What is the effect of power extraction on turbofan compressor and turbine maps?

Scholz, D. et al.: "Fuel Consumption due to Shaft Power Off-Takes from the Engine", AST 2013 - Workshop on Aircraft System Technologies, 23-24 April 2013, Hamburg, Germany
Shaft power extraction, no matter if taken from the High-Pressure (HP) shaft or the Low-Pressure (LP) shaft, will reduce the speed of this shaft. This reduces the mass flow [...] and the thrust [...]. Constant thrust regulation applied to the engine (achieved today by the Full Authority Digital Engine Control, FADEC) will primarily result in an increase of fuel flow, increasing the Turbine Entry Temperature, TET. Higher pressure in the combustion chamber and higher turbine load together with a reduced shaft speed will enlarge the angle of attack at the compressor blades and therewith slightly lift the pressure rise achieved at each stage. In this way, shaft power off-takes also result in closer operation to the surge line. [...]
If shaft power is taken from the LP shaft, its speed will reduce. Also, the fan speed is reduced, which decreases the thrust considerably. With the engine controls increasing the TET, the HP shaft (in this case not affected by power off-takes) will even increase its speed and mass flow through the LP turbine and compressor compared to the original situation. [...]
If shaft power is taken from the HP shaft, its speed will reduce and so also the mass flow through the LP compressor and turbine. With the engine controls increasing the TET, the situation is rectified.
Low thrust ratings always mean a high relative power extraction P/T [shaft power off-take P, jet engine thrust T] and high relative specific fuel consumption. At high thrust ratings, the relative power extraction P/T is smaller and the relative specific fuel consumption is less.


From my textbook, Fluid Mechanics and Thermodynamics of Turbo-machinery by Dixon, it is explained that they find the results for the working line empirically. This corresponds to the line with the black dots on the diagram you provided.

Essentially, your test rig is made up of a compressor that is connected to a downstream throttle. It is the size of the throttle (in a real engine, this corresponds to the size of the nozzle) that is going to determine the test working line (called an operating line if it does not pass by the Design Operation Point). In other words, a different operating line corresponds to a different size throttle.

Then you vary the speed and measure the obtained pressure ratio. Connecting the dots will give you the working line.

ADDED DETAIL:
You have to know the size of the throttle because it will give you valuable information regarding your exit configuration. This has to do with the fact that the nozzle will usually be chocked, which will fix your non-dimensional mass flow through the nozzle. But that's a whole other topic in itself!

I did my best to answer your question, sorry if it does not help, I am only a student! If you want details of the calculations for compressor maps, you should check out chapter 5 of Dixon.


Can thrust reversers possibly collapse due to strong crosswinds?

It is impossible to tell from the video what the reason or cause was, this is all speculation.

Most likely it was a malfunction of the thrust reverser. There is a good change that the crew was aware of the problem before take-off; the Airbus A330 may be dispatched with one or even both thrust reversers unserviceable according to the minimum equipment list (MEL)

Another possibility is that the crew accidentally only activated one thrust reverser. Given the firm landing (as it should be given the strong crosswind) they might have erred in the heat of the moment.

It is unlikely that the decision to use only one reverser was on purpose if two reverser were serviceable. On the ground the aircraft has a tendency to weathercock into the wind because of the vertical tail. Selecting only the windward thrust reverser aggravates that tendency.


In Malaysia, can someone become a LAME through self study rather than training school?

Unfortunately, it is not possible to become a licensed AME in Malaysia entirely through self-study. It takes between two and seven years to become licensed as an AME in Malaysia, and that includes two years of practical/on-the-job training at a Malaysian aviation facility/company. You could, in theory, study the theoretical material and try to pass the test, but if you don't go through a Part 147 training program it will take much longer to become licensed.


With power off, is it possible to maintain constant altitude for some period of time, until the stall speed is reached?

Yes, assuming your are flying level with the engine running and then you turn the engine off, the following will happen:

Without power from the engine, the drag will cause the airspeed to decrease.
Lower airspeed at the same angle of attack implies less lift. Since you want to maintain altitude, lift needs to stay the same (your weight has not changed). Thus, you have to increase pitch.
Eventually, you will reach the critical angle of attack and flow separation will occur, i.e. you stall. The airspeed at which this happens is called the 1-G stall speed, although one can stall any speed.


What is this transport aircraft, and why does it sometimes cary an air data boom when the Soviet Buran Space Shuttle is on top of it?

The only aircraft that ever had a shuttle on top of them is NASA's modified Boeing 747 and Russia's Myasishchev and the Antonov 225. All of them were subsonic.

The one in the picture is the high wing 6 engine Antonov 225.

The air data boom is likely to gather data for test flights for the shuttle. Subsonic craft will affect the air in front of them (that's why you can hear them coming) so putting the sensor on a boom will help put the sensors in clean air.


Why does Logan Airport's Runway 32/14 only have arrivals on the 32 heading?

(Much of my answer below will be drawn from "The 30-year saga of 14/32", a 2006 Boston Globe article which is unfortunately subscription-only but which I have access to via an institutional database.)

Runway 14/32 has been a long-standing bone of contention at Boston Logan.  Like many urban airports, Boston Logan is constrained by the fact that there are many people living nearby who don't particularly like jets flying low over their houses, and who are willing to organize in opposition of any increase in operations at the airport.   Massport, the organization in charge of Boston Logan, had originally proposed to build a new runway in the late '60s.  This met fierce opposition from community members in East Boston who were opposed to additional take-offs and landings over their homes.

  [I]t's taken no less than 33 years for 14/32 to become reality, a testament to how politically charged Logan expansion has been ever since demonstrations in the 1960s, when East Boston mothers lay in the streets to protest the destruction of Eastie parks and homes.  ...

The Hyatt Harborside Hotel (now the Hyatt Regency Boston Harbor) was built in the 90s to act as an impediment to runway expansion:

  In the 1990s ... Frederick P. Salvucci engineered construction of the 270-room Hyatt Harborside Hotel, a stone's throw from the end of the new runway, largely to create as big an obstacle as possible to Massport extending 14/32 or using it for planes flying over the city.

In the end, Boston Logan was barred by court order from allowing takeoffs from 32 or landings on 14, except in emergency:

  By court order, use of 14/32 will be restricted to planes taking off and landing over Boston Harbor, so Massport will be legally forbidden - except in emergencies - from using the runway to let planes take off or land over South Boston and downtown.

This still allows for three runways to be operative when winds are from the northwest or southeast (along with 15L/R or 33L/R), so the hope was that even this "half-runway" would result in fewer delays at BOS during bad weather.  Whether or not this has panned out to be true in the decade since, I do not know.


The key when selecting an aviation mechanic or shop to maintain your newly purchased plane is "time in type": You would not take a Cessna 172 to the United Airlines maintenance facility at JFK, not would you take an A380 to the local Cessna service center (even though it would be perfectly legal to do so).

If you're buying a new aircraft (of any type) the manufacturer will be able to recommend an authorized service center for you, and you'll probably want to use an authorized service center (especially for warranty work).

If you're buying a used aircraft you can still contact the manufacturer and ask about authorized service centers. They will usually be happy to give you a list of places near you that can work on your aircraft, and who are blessed by the factory to perform warranty service, complete mandatory service bulletins where the manufacturer is supplying parts / covering labor, etc.

Aside from manufacturer recommendations there are a lot of other ways to find a maintenance shop that beat simply asking Google and picking one at random.

For the most common single-engine piston aircraft (your typical Piper Cherokee, Cessna 172/182, etc.) you can almost certainly find a mechanic at your local general aviation airport - ask the FBO where you're storing the plane for recommendations or talk to other pilots on the ramp about who they use for maintenance.

For more esoteric aircraft (high-performance singles, twins, vintage/classic/warbirds, etc.) your best resource is often a type club (e.g. The American Bonanza Society for Beechcraft Bonanzas, or ICS for the Piper Comanche) - Google can help you track down a type club, and the members can help you find mechanics who have experience working on your particular airplane.
Type clubs are also a great source of other information (like where to find parts).


Was there a historical requirement to announce altitude, temperature, etc?

As this may be most common among airlines, this is not a requirement whatsoever administered by the FAA or any other aviation governing body. This is more so considered a tradition usually when the plane reaches cruise or is about to land. No such modern airline or any airline in the past has required this to be announced to its passengers.


Where is the best centre of gravity for planes like the Berkut 360?

I cannot tell you the exact location or the locus of the CoG for the current aircraft but I can provide you a method that you can use to find the appropriate location for the aircraft to be statically and dynamically stable in flight that you can use for any future aircraft.

I'll put it simple, CoG alone means nothing, you need to know the Neutral Point (NP) of your aicraft, that is the point that if you place CoG there you'll have neutral stability (i.e. the airplane will not tend to increase or decrease a pitch up input you give with your RC). The NP is considered in practice the aft limit of your CoG.

What matters in terms of stability and control is the distance of CoG from NP that is given by what we call Static Margin (SM). An empirical rule for SM is given as

$ SM \equiv \dfrac{x_{NP}-x_{CoG}}{\bar{c}} = +0.05\ \ \ ...\ +0.15 $

where $c$ is the mean aerodynamic chord (MAC) and $x=0$ is at the leading edge of the wing's MAC.

Now, a general method to compute the NP is to use an open-source Vortex-Lattice Code like AVL of MIT (Mark Drela) (http://web.mit.edu/drela/Public/web/avl/). If you know the geometry of your airplane, and of-course you know it since you're building it, you can make the model of the airplane and with AVL you can obtain the NP from an analysis.

If you are lazy, and need an empirical and fast way to compute your NP x location then you ca.. Whoops! winglets as Vstabs... I am not sure about the validity of empirical formulas for this aircraft and you should do the algebra of flight mechanics to deduce them. It's cool but a VLM code is more general.

If you find the $x_{NP}$ you can find the $x_{CoG}$ values that satisfy longitudinal static stability criteria and then with trial and error decide what value in this range gives you the best flying experience as there is no "best" value in engineering if you don't specify the optimization constraints.

Good luck!