Are aircraft pilots required to fly runway heading for a certain distance?

The initial turn should be made at 400 feet AGL.
Unless otherwise specified in the departure procedure, the initial turn should be made when reaching an altitude of 400 feet above the runway elevation as specified in the AIM:

Unless specified otherwise, required obstacle clearance for all departures, including diverse, is based on the pilot crossing the departure end of the runway at least 35 feet above the departure end of runway elevation, climbing to 400 feet above the departure end of runway elevation before making the initial turn, and maintaining a minimum climb gradient of 200 feet per nautical mile (FPNM), unless required to level off by a crossing restriction, until the minimum IFR altitude. A greater climb gradient maybe specified in the DP to clear obstacles or to achieve an ATC crossing restriction. If an initial turn higher than 400 feet above the departure end of runway elevation is specified in the DP, the turn should be commenced at the higher altitude. If a turn is specified at a fix, the turn must be made at that fix. Fixes may have minimum and/or maximum crossing altitudes that must be adhered to prior to passing the fix. In rare instances, obstacles that exist on the extended runway centerline may make an “early turn” more desirable than proceeding straight ahead. In these cases, the published departure instructions will include the language “turn left (right) as soon as practicable.” These departures will also include a ceiling and visibility minimum of at least 300 and 1. Pilots encountering one of these DPs should preplan the climb out to gain altitude and begin the turn as quickly as possible within the bounds of safe operating practices and operating limitations. This type of departure procedure is being phased out.

(AIM 5-2-6 Departure Procedures, emphasis mine)
The Canarsie climb at JFK does not include any special instructions for when to make the turn:

CANARSIE CLIMB: Climbing left turn direct CRI VOR/DME. Make turn east of
CRI R-039 (remain within JFK 4.5 DME), then via CRI R-176. Cross CRI 2 DME
or JFK R-253 at or above 2500, thence . . . .

(Kennedy Five Departure)
I would therefore start the turn at 400 feet. In principle, this would allow turning before reaching the far end of the runway, but only for a very good climb performance or a very long runway.


I would believe that you are talking about Aircraft Design Group classification which is based off of aircraft wingspan and tail height. These classifications can also dictate what taxiways a certain model of airplane can use.

Group I: Wingspan - Less than 49' (15m)
Group II: Wingspan - Between 49' (15m) and 79' (24m)
Group III: Wingspan - Between 79' (24m)  and 118' (36m)
Group IV: Wingspan - Between 118' (36m) and 171' (52m)
Group V: Wingspan - Between 171' (52m)  and 214' (65m)
Group VI: Wingspan - Between 214' (65m)  and 262' (80m)

PDF for list of Boeing Airplane Group classifications


What is the maximum fuel amount that fits into the rare Boeing 737-700ER version?

According to the Payload/range diagrams from the Boeing Airplane Characteristics for Airport Planning manual (page 95), the fuel capacity is 32 539 kg (71 737 lb)


Why does flying not have any age restrictions like driving does?

Short answer: the US government agreed with you 3 years after her record flight.

In the FAA reauthorization act of 1996, the following clause was added to 49 U.S. Code § 44724 - Manipulation of flight controls:

  (a)Prohibition.—No pilot in command of an aircraft may allow an individual who does not hold—

  (1) a valid private pilots certificate issued by the Administrator of the Federal Aviation Administration under part 61 of title 14, Code of Federal Regulations; and
  (2) the appropriate medical certificate issued by the Administrator under part 67 of such title,
  to manipulate the controls of an aircraft if the pilot knows or should have known that the individual is attempting to set a record or engage in an aeronautical competition or aeronautical feat, as defined by the Administrator.

Per 14 CFR 91 (can't find the exact text right now, but I know this is true from my flight training), you cannot obtain a student pilot's license until age 14 (so, no soloing until then, let alone a long-distance trip) and a private pilot's license until age 16 (for gliders).  You can't get a private pilot's license for your typical single engine aircraft until age 18.  A sport pilot's license is possible by age 17, but is limited on the aircraft you can fly (that said, a coast-to-coast trip has been flown in a Piper J-3 Cub, which fits under the sport pilot license) and conditions you can fly in.

Hence, it would not presently be legal to do what Vicki did in 1993.  According to a NY Times article covering another young pilot, Jessica Dubroff (aged 7 at the time of her fatally unsuccessful attempt at a coast-to-coast flight):

  Jessica was breaking no aviation rules when she flew.  The plane had dual sets of controls, meaning that the flight instructor was legally considered in charge and had the ability to take control instantly, though the plans called for Mr. Reid to take over only in an emergency.  But within hours of the crash, Federal authorities announced that they would re-examine existing regulations on underage pilots.

This would have preceded the addition to the USC quoted above.


The most common way to deal with noise in the cockpit is to get yourself a noise canceling headset. There are a bunch of models out there but the most common seem to be the Bose and the Lightspeed. I personally have the lightspeed and will attest to at least a 30%-50% perceived noise reduction over my old passive headset.


Is an AFSP registration required for rotorcraft rating?

The problem is that person writing the FAQ seems to not understand the category and class system for pilot certification. The interim final rule (the actual regulation) does not make the distinctions you have discussed from the FAQ. See https://www.flightschoolcandidates.gov/IFR_Alien_Pilot.pdf as Category 3 does not specify an FAA pilot certificate category or class, just MTOW of 12,500 pounds or less, which means a R-22, R-44, Sikorski/Schweizer 300, seaplanes, gyrocopters, gliders, lighter than air, etc. unless specifically exempt elsewhere.

According to https://www.flightschoolcandidates.gov/TSA-2004-19147-0337.pdf the measure that they use with regards to whether or not you are subject to the "threat assessment" is whether you are taking training that will "substantially enhance piloting skills" but then it further states that the requirements are for the "initial pilot certificate, including a private, recreational, or sport pilot certificate."

It would be very hard to argue that training towards a certificate in RH is not going to "substantially enhance piloting skills". However, when they came up with the FAQ it appears that they have ignored that there is any category of aircraft outside of that of airplane (and any class outside of land airplanes).

Adding on RH (or Instrument-Helicopter) to ASEL/ AMEL/ Instrument-Airplane would be your "initial pilot certificate" in the rotorcraft category, helicopter class, or your "instrument rating" for that category.

For the sake of not getting yourself or your flight school in potential serious trouble, you should probably apply under the Category 3. If I were in your position I would omit the "probably" of the last sentence, but I am not a government regulator and I am not an attorney, so there is always a degree of uncertainty with regards to my personal interpretation of this material.


Why does the Tu-134UBL have a sharp/pointed nose cone?

According to Wikipedia, the UBL variant of the TU-134 was designed/used to train TU-160 crew, and is using its nose-cone.
As to why, I think we can only assume. I think that a fair assumption would be that it contains the radar from the TU-160 (or a stripped-down version of it), and/or so the crew will have a similar visibility as they would on a TU-160.
The overall performance differences between the TU-134 and 160 are too far apart (the -134 being a subsonic airliner and the -160 being a supersonic bomber) for the shape of the nose cone alone to make any sort of a significant difference.


If turning off electronic gadgets is so important, why are there no detectors used to find them?

Three reasons I can think of:

It's easy to detect the general presence of a specific transmitting device (a WiFi antenna, say), but very hard to precisely localize it. They could tell if there's one on the plane, but someone with a very sensitive piece of equipment would have to walk up and down the aisles pointing it at people to actually find it in somebody's pocket. And cellphones (when not in use) are generally burst transmitters: they don't broadcast continuously, they just "ping" the tower every so often. This means it could take a long time and a lot of aisle-pacing.
Many "electronic devices" which are banned are entirely passive and have no traceable[*] emissions. Think cameras, handheld GPS receivers, iPods. (On the other hand this passiveness also means they are extremely unlikely to harmfully interfere with the operation of the airplane, but right or wrong, such devices are still banned in some cases.)
It's not that important. There are a few incidents where electronic interference is suspected as a possible factor, but no conclusive evidence. As soon as there is actually a fatal accident where an electronic device can be conclusively blamed as the cause (and I doubt this will happen), the airlines will be a lot more willing to spend the kind of money that would be required to implement this.

For a full, evidence-based discussion of the actual risks, I refer you to this question on Skeptics Stack Exchange: Are personal electronics a risk to commercial aviation?

[*] No traceable emissions. All electronic devices generate some very, very tiny incidental signals. But these are so weak that they will be virtually impossible to detect on a crowded plane filled with its own (approved) electronics. Such emissions are measured in laboratories with extremely sensitive antennas in special, heavily-shielded rooms under carefully controlled conditions.


What are the main differences piloting Boeing vs. Airbus aircraft?

On a pilot-vs-FBW system perspective, as mentioned in the comments to the question, the most notable difference is the authority priority:

Boeing trusts more the pilots: they can supersede the Fly-by-wire automatic commands by exerting enough force on the controls
Airbus trusts more the FBW system: if the system is fully functional ("Normal law") it will always have priority over the pilots to protect the aircraft and keep it in the envelope, but they still have room for "non-standard" maneuvers, e.g. commanding bank angles between 33° and 60°. The autopilot can be activated and de-activated at will by the pilots, and it sits on top of the FBW envelope protection.

One of the most famous examples where this comparison emerges (and the subsequent debate about which approach is better) is the China Airlines 006 accident.
I won't go into detail, there is the accident report that will provide much more information that I can remember, but suffice to say that this 747 was recovered from a quite unusual attitude

As mentioned in the wiki article, the report states that the passengers were subject up to 5 gs during the maneuver and the stress on the horizontal tail surface has been so great that as a result it was damaged:

The usual argumentation goes along the lines that, would this had been an Airbus, the pilots would not have been able to save the aircraft.
See for example this PhD thesis at page 184 of the pdf, section 6.2.3 "Pilot Authority at the Boundary":

  It is likely that if the aircraft had prevented the crew from initiating control commands that would lead to aircraft damage, the aircraft (and passengers) would have been lost.

The problem with such a comparison? It focuses on the recovery after the unusual attitude was achieved and totally forgets about the sequence of events that lead to it or, to the very least, assumes that an Airbus would have responded in the same way to the preceding events (then why make a comparison at all?)

An honest comparison would take into account this and acknowledge that an Airbus in Normal Law would not enter a spiral dive in the first place, even with an engine out, as bank protection/attitude-hold would prevent it.


How to interpret the term "standard" which is found in FAA's Obstacle Departure Procedures (ODP) and Standard Instrument Departure Procedures (SID)?

The definition of standard minimum visibility for departure is found in CFR §91.175 Takeoff and landing under IFR.

f) Civil airport takeoff minimums. This paragraph applies to persons
operating an aircraft under part 121, 125, 129, or 135 of this
chapter.
(1) Unless otherwise authorized by the FAA, no pilot may takeoff from
a civil airport under IFR unless the weather conditions at time of
takeoff are at or above the weather minimums for IFR takeoff
prescribed for that airport under part 97 of this chapter.
(2) If takeoff weather minimums are not prescribed under part 97 of
this chapter for a particular airport, the following weather minimums
apply to takeoffs under IFR:
(i) For aircraft, other than helicopters, having two engines or less—1
statute mile visibility.
(ii) For aircraft having more than two engines— 1⁄2 statute mile
visibility.
(iii) For helicopters— 1⁄2 statute mile visibility.

The AIM 5−2−8 confirms your intuition about climb gradients.

b. What criteria is used to provide obstruction clearance during
departure?

Unless specified otherwise, required obstacle clearance for all departures, including diverse, is based on the pilot crossing the
departure end of the runway at least 35 feet above the departure end
of runway elevation, climbing to 400 feet above the departure end of
runway elevation before making the initial turn, and maintaining a
minimum climb gradient of 200 feet per nautical mile (FPNM), unless
required to level off by a crossing restriction, until the minimum IFR
altitude. A greater climb gradient may be specified in the DP to clear
obstacles or to achieve an ATC crossing restriction.

Note that visibility minimums do not apply to Part 91 aircraft. Also note that standard takeoff minimums do not have a minimum ceiling while published departure procedures almost always have a minimum ceiling or climb gradient—and often have both.


Which are the requirements to fly a N-registered aircraft operated by a non-US airline?

There are a few aspects to this. First off all N-Registered aircraft must be owned and operated by a US based entity. As has been mentioned this could be any US based company or US resident. In reality foreign companies can set up US based branches or entities fairly easily under which to own the aircraft. The aircraft must also comply with all FAA regulations for maintaining the N-Number (annual inspections etc.) This means that the aircraft must be inspected at an FAA approved/licensed facility (they do exist outside the US). The planes can (if practical) be flown back into the US for inspections if no foreign facility is available.

When it comes to flying the plane the pilot must carry what ever is locally required to fly in and out of that country/airspace both from an equipment standpoint and a pilot standpoint. Many countries will accept/recognize different pilots certificates for inbound international traffic, that is the subject of its own question as there are many combinations out there. For what its worth the US FAA certificate and the ICAO/EASA certificate are pretty highly recognized around the world.


How does the wraparound wing design reduce drag?

It does not reduce drag, but creates more of it.

This concept is called a "box wing" and is one variety of closed wings.  Another is called a "joined wing" and was popularized by Julian Wolkovitch. However, only people who don't understand how a wing produces lift can be enticed by this concept - it has too many drawbacks for the modest reduction in induced drag it offers. The general idea is to sweep the horizontal surface of a T-tail forward and stretch it out until it joins the backward-swept wing and relieves it in bending, similar to a strut.

Similar to winglets, the vertical extension of the wing structure will involve more air into the production of lift, which reduces induced drag, but this extended structure must be bought with a hefty mass increase which will reverse the gain in induced drag, because much more lift needs to be produced in order to lift the additional structure.

Note especially that the rear wing (which is supposed to act as a tail surface) will be loaded in compression in order to support the wing. Making this rear wing narrow will make it susceptible to buckling, which can only be avoided by a stiff and heavy structure, and will increase its friction drag due to its much lower Reynolds number. When a winglet-like element is added between wing and horizontal tail, this winglet is now loaded in bending and will also need to be made much stronger and heavier than a conventional winglet.

Calling this a "Prandtl plane" is to completely misunderstand the 1924 publication of Ludwig Prandtl, who very well understood how wings create lift, about the benefit of box wings.


How does a constant-speed propeller work?

Before we get started, I should mention that the most basic constant-speed propellers were driven by balancing air pressure and centrifugal force. The blades were shaped in such a way, or equipped with a counterweight that would cause the blade to intrinsically move to a shallow pitch. However, when air was moved over the blade, it would begin to overpower the counterweight and push the blade to a higher pitch. It's a pretty ingenious design that meant that the prop would automatically be at a high RPM when the plane was moving slowly (takeoff, landing, climbs),  and would automatically move to a higher pitch when the plane sped up for cruise. There is even a single-bladed propeller that utilized this design very efficiently for light aircraft. The problem is that this type of propeller is not pilot-adjustable, and I am assuming you are wondering about adjustable props, so that's what we'll talk about from here on.
In the first picture, observe that the pilot valve is resting directly on the flyweights (separated by a bearing). The second picture better depicts the valve system. So we see that the speeder spring is pushing down on the top of the pilot valve's shaft, which is in turn resting on the flyweights.
First off, the flyweights are turned by the crankshaft, so any change in engine RPM is immediately reacted to.
There are a few ways that the propeller is attached to the piston, and a rack and pinon type gear system is common and easy to imagine. The rack is fixed to the piston so that when it moves, the prop blade's pinion gear is rotated and thus the blade is rotated. Another common type uses a peg that is offset from the center of the blade's circular base. When the piston moves, it pushes or pulls on the peg and because the peg is offset it causes the blade to twist.
Overspeed: When your airspeed increases.
When the RPMs increase, the centrifugal force causes the flyweights to want to spread apart in order to conserve momentum. Because they're in an L shape and have a hinge in the corner, this causes the lower part to rise up, pulling the pilot valve up and compressing the speeder spring. When the pilot valve is raised, pressurized oil from the pump is allowed to flow into the prop hub through a tube that passes through the center of the hub piston. The oil fills a cavity in front of the piston, pushing it backwards. The prop blade is rotated to a higher pitch (closer to feather) which slows the engine RPM. When the RPM is reduced, the flyweights will be under less centrifugal force, and the speeder spring will push them back to equilibrium (on-speed), pushing the pilot valve back down to block the hub oil tube from gaining or losing oil.
Underspeed: When your airspeed decreases.
When the RPMs decrease, there is less centrifugal force acting on the flyweights. Due to their shape as described earlier, they are no longer able to push up on the speeder spring with the same force as before, so the compressed spring will begin to expand. This brings the top of the flyweights in, and their bottoms down. When their bottoms move down, the pilot valve moves down as well and unblocks the hub oil tube. Positive oil pressure in the hub and the blades' built-in tendency to want to move to a low pitch pushes the oil out of the hub and back into the oil system. The piston moves forward and the blades rotate to a low-pitch condition. The flyweights do not necessarily return to equilibrium, especially if you manually set the spring to maximum compression with the prop lever: you want the prop to stay at minimum pitch no matter what.
Loss of oil pressure:
Oil pressure is constantly pushing against the bottom of the pilot valve, trying to force it upwards. The speeder spring is resisting, and while the flyweights are on-speed, the whole system is in equilibrium with the valve blocking the hub tube. When you lose oil pressure, that pressure is no longer holding the valve up and the speeder spring will win, pushing the valve down and allowing the oil to flow out of the hub. This resets the prop to the low-pitch climb setting, giving us maximum power because that's more useful than maximum speed in the emergency situation that is probably about to occur.
So why do we do this?
All propellers are set at a pitch. Theoretically, a propeller is pitched to move forward a certain distance each revolution, just like a screw moving through wood. But unlike wood, air is fluid and difficult to grip. If you imagine screwing a screw into a board, the only way to make it go in faster is to turn it faster. This is because the screw's pitch is fixed. If you could space out the rungs on the screw (increase the pitch) the screw would move through the wood faster but it would become much harder to turn.
An airplane's propeller works much the same way. When we first take off, we need to impart maximum power into the air and it doesn't matter if we don't move forward very far for each revolution, because we're not going very fast anyway. We just want to move as much air as possible. But we will reach a certain point where the only way to speed to is to increase the number of prop revolutions, and that's impractical with our engines. The only alternative is to change the pitch of the blade. We change it to a pitch which allows us to move forward a greater distance with each revolution, in exchange for less power being imparted into the air each revolution. Luckily, we don't need to pump out so much energy, just enough to keep us from slowing down.
If you like numbers, imagine we have an engine and propeller that theoretically (at perfect efficiency) moves forward 1 foot for each revolution, and it can make 1 revolution per second, giving a maximum forward speed of 1 foot per second. That's perfectly fine when we're taking off: we might be moving forward at 0.5 fps, and we have some air being blown backwards a 0.5 fps. When when we level off at cruise, we're stuck at 1 fps. But we want to go 3 fps and we know our airframe can handle it. The easiest option is to turn the engine three times as fast, but unfortunately that would send some pistons flying out of the cowling. So we have to change the prop pitch to one that moves forward 3 feet for each revolution, that way it's still turning at the same rate, but it will move us forward three times as far. Or more likely we're still going 1 fps but only 1/3 RPM and burning 1/3 the fuel! It's here that you can see the issue: if we're burning 1/3 the fuel, we're only imparting 1/3 the energy into the air through the prop, and there's no way we could climb or accelerate quickly (if at all) at that setting.
A final way to think about it is just like the gears on a car. Your transmission allows you to, at 1500RPM, go 10mph or 60mph or any speed in between. The problem is that if you try to accelerate from 10mph to 60mph while maintaining 1500RPM, it will take a much longer time than if you were to bump it up to 2500RPM. High gears are great for cruising and maintaining speed, but are not great for accelerating. They allow you to keep your RPMs low, your torque low, and your fuel burn low, because you don't need that extra energy. A high prop pitch is exactly the same.
A note about multi-engine aircraft:
They are just the opposite of singles. Where singles require positive oil pressure to increase blade pitch, multis require positive pressure to decrease it. This is because in a multi, you want the propeller to feather automatically if you lose oil pressure (because of an engine failure). This removes a significant amount of drag from that side of the aircraft.
They are equipped with either a spring or a nitrogen charge in the hub that is pressurized, pushing the hub piston back to the feathered position. The prop governor works the same way but the pilot valve directs oil to push against the back of the piston, moving it forward and compressing the spring/nitrogen, moving the prop to a lower pitch.
Some are also equipped with an unfeathering accumulator. This is a bottle with a piton in the top (also charged with nitrogen) that fills up with oil when the engine is running. When you bring the prop out of high RPM, the bottle is sealed off from the rest of the system. If you lose oil pressure, the prop will feather like it's supposed to, but there will still be pressurized oil in the accumulator. That way if you manage to get your engine issues taken care of, you can push the prop lever full forward, open the valve to the accumulator, and the pressurized nitrogen will force the oil out of the bottle to put the whole system under positive pressure for a few seconds. This positive pressure moves the hub piston forward and unfeathers the prop.
Now you might think "If multis feather when they lose oil pressure, why are all those twins out on the ramp sitting there with low-pitched props?" Well, they have centrifugal locking pins that disappear when the engine RPM is high enough. If it gets low, they will fall back down into a groove around the hub piston or its shaft and lock it into a low-pitch state. This is not a fool-proof system, however, because the pins have been known to stick, and people have been known to shut the engine off with the prop lever less than full-forward. In that case you either need to get some strong guys out there to manually twist the prop back, or you need to waste a chunk of your starter's precious life turning the engine over to create oil pressure to unfeather the prop. Most engines can not start in a feathered state due to the huge drag from the blades being perpendicular to their direction of rotation.
On turboprops:
Although it can vary engine to engine, turboprops use similar systems to multi-engine aircraft but at much higher pressures and with the ability to enter beta mode (reverse pitch). That introduces problems mainly in that the engine will very quickly overspeed with the blade pitch is 0 and the prop is generating no thrust/load. I'm not going to attempt to explain it because I've never really worked with one. This guy seems to do a good job, though.


What amount of lift would be created in the fallacious "lift from equal transit time" theory?

The theoretical lift coefficient of a NACA 4412 at the critical angle of attack (about 16 degrees) is approximately 1.7.
\begin{equation}
c_\mathrm{l}=1.7
\end{equation}

For our purposes, that same airfoil has its upper "surface" about 1.03 times as long as its lower, which can be seen by using the distance formula on the coordinates or integrating the cambered NACA airfoil equation. Here is the distance-formula method applied to the Airfoil Tools numbers (thanks to ROIMaison for making me check this calculation):

On average, therefore, the fallacy would predict the air moving along the upper surface at about 1.03 times the velocity as along the lower in order to join up properly.

Making all the assumptions from the NASA link, Bernoulli's equation says
\begin{equation}
P_1+\frac{\rho V_1^2}{2}=P_2+\frac{\rho V_2^2}{2}
\end{equation}
Let's represent the lower surface with subscript 1 and the upper with subscript 2. The respective velocities are averages across the surfaces. We have
\begin{align}
P_1-P_2&=\frac{\rho (1.03V_1)^2}{2}-\frac{\rho V_1^2}{2}\\
&=\frac{609}{20000}\rho V_1^2\\
\end{align}
So the average difference in pressure coefficient (i.e., the lift coefficient) is given by
\begin{equation}
\mathrm{avg}(c_\mathrm{p_{ETT}})=\frac{609}{10000}\frac{V_1^2}{V^2}=c_\mathrm{l_{ETT}}
\end{equation}
where $V$ is the freestream velocity and ETT stands for equal transit time.

We have another expression for pressure coefficient that we can apply to get a final value. We end up with
\begin{equation}
c_\mathrm{l_{ETT}}=\frac{609}{10000}\frac{V_1^2}{V^2}=1-\frac{V_1^2}{V^2}
\end{equation}
or
\begin{equation}
\frac{V_1^2}{V^2}=\frac{10000}{10609}
\end{equation}
and therefore
\begin{equation}
c_\mathrm{l_{ETT}}=\frac{609}{10609}\approx.0574 \approx .034c_\mathrm{l}
\end{equation}
which is less than 5% of the actual value. However, it is important to keep in mind that the fallacy predicts no lift change with angle of attack (just one of the many reasons it is silly), and so the relationship between $c_\mathrm{l_{ETT}}$ and $c_\mathrm{l}$ varies with angle of attack for a given airfoil. For the 4412, they meet at just over a -5° AOA. For a symmetric airfoil, they meet at zero AOA. For any other airfoil, the calculation must be redone with the correct path lengths and actual lift coefficients, although magnitude of the result is not likely to change dramatically.


On a centrifugal compressor impeller what is the difference between the radial vanes and rotating guide vanes?

The radial vanes are the main compression channels, where air gets squeezed into 5 - 10 bar and gets slung out of the tip traveling at 500 m/s.

The rotating guide vanes scoop the incoming air into the impeller vanes, kind of like a pre-whirl tower. They’re at the inside diameter and travel at much lower linear speed, subject to lower centrifugal force.

This picture was used in an earlier answer, and illustrates the different roles of the channels and vanes. As the pressure ratio on the horizontal axis increases, we can observe the following:

Efficiency decreases: losses are higher for higher single stage pressure ratios, which is the main reason that commercial aircraft turbine engines use axial compressors.
Impeller height increases. The curved shape allows for a more gradual change of direction of the airflow: inflow is in axial direction, outflow in radial direction. A large potential source for efficiency loss.
Inside vane shape points more and more in radial direction: it scoops the airflow into the impeller, and pre-whirls into the radial direction that will be imposed by the impeller.

The right-most impeller combines an axial stage with a centrifugal stage. In an axial compressor the rotor is followed by a stator, in our axial-centrifugal combination there must be no stator because we want whirling flow now.

With advances in production technology, this has resulted in impeller shapes with double curved inlet vanes, such as above. The inner bits of the impeller are subject to much lower stresses and may be shaped much more funkily than the impeller outer diameter.


What are some of your favorite flying and piloting related lessons or concepts to share with your non-pilot friends?

There exists a machine with which you can casually swim through the atmosphere to explore mountain tops, deep canyons, and vast expanses.  You need no special degree or unusual intellect to use it.  In fact, morons do it!  A little over 100 years ago it would have been called magic.  Today they are so common that many consider them a nuisance or necessary inconvience.
One type (there are A LOT of different types) is a million pound machine that can carry 500 people seven miles above the earth at 85% the speed of sound and cross entire oceans in mere hours.  How do you just not fall to your knees, mouth agape, in awe of such a thing??
Oh...because there are so many of them, and they're so safe, and so cheap to use that anyone with a few hundred dollars can bum a ride to anywhere on the planet while garbed in clothing a notch above underwear.
The fact is that we are living in SciFi land from the perspective of someone three generations ago.
And that's just airplanes.


Did Wolfgang Langewiesche ever change his mind about rudder pedals?

NO

There is no written record that I have found in researching this question that Langweische ever 'recanted' his beliefs. I cannot source or cite this negative however. I don't actually like this question, since only an answer that he did recant can be sourceable. Any cites showing him supporting his own written beliefs could be disputed by saying "but what about later in life?" This means that a negative answer can only be opinion.

It's not like he left in his LW&T the statement that everything he had written previously was a lie.


Is a hold in lieu of a procedure turn specifically one hold on an RNAV approach?

When flying a hold-in-leiu-of-procedure-turn and the exemptions from that procedure are not met, you must fly that procedure exactly once. From the AIM, 5-4-9(a)(5):

  The  holding  pattern  distance  or  time
  specified in the profile view must be observed. For a
  hold−in−lieu−of−PT,  the  holding  pattern  direction
  must  be  flown  as  depicted  and  the  specified  leg
  length/timing  must  not  be  exceeded.  Maximum
  holding  airspeed  limitations  as  set  forth  for  all
  holding
  patterns apply.
  The holding pattern maneuver is completed when the aircraft is established on the inbound course after executing the appropriate entry. If cleared for the approach prior to returning to the holding  fix,  and  the  aircraft  is  at  the  prescribed altitude, additional circuits of the holding pattern are
  not necessary nor expected by ATC. If pilots elect to make additional circuits to lose excessive altitude or to  become  better  established  on  course,  it  is  their responsibility to so advise ATC upon receipt of their
  approach clearance.

Further notes: I'm not sure quite what you mean by losing 2000 feet in "half a hold", but if you got a clearance to maintain 4000 until established, you could start your descent immediately after crossing ODAZO, giving you 8 miles plus a one-minute turn to descend. At 120 kt, that's 4 minutes for the 8 miles, so 5 minutes for 2,000 feet or 400 ft/min - perfectly reasonable.

Finally, you mention that "When directed by ATC to fly a straight in approach, the hold-in-lieu is not required." Your statement should be stronger: as when NoPT is printed on the chart, a straight-in clearance forbids the procedure turn/HILOPT unless you ask for and receive approval from ATC.


Why did some Spitfire variants have their wings clipped?

It would increase the roll rate, and it would increase the maximum possible airspeed at lower altitudes.  Generally speaking, decreasing the wing loading doesn't help to maximize the achievable airspeed unless an aircraft is near its service ceiling.  At low altitudes, increasing the wing loading by reducing the wing area often increases the maximum achievable airspeed, by reducing profile drag.


Scholarships dot com has a list of a few scholarship programs:  https://www.scholarships.com/financial-aid/college-scholarships/scholarships-by-type/aviation-scholarships/

However I am not sure if you are looking to get aviation training for a career, or for personal fulfilment.  There are also some schools that offer various aviation related programs (Embry-Riddle being the best known in the US).  Some of them may have separate scholarship programs that are not specifically listed on the Scholarships.com site.

There are also some places throughout the world that offer "learn to fly" programs.  I have a friend that works for a company that even offers their employees all the coursework and flying required for a private pilot license as a training subsidy (Kollsman, in New Hampshire).


What are the protocols of flying over conflict areas?

This is horrendous Incident, and my heart goes out to the victims Families who lost their loved ones.

The FAA filed a special Warning flying over Crimea back in April but apparently not where the airplane went down.

The procedure is to avoid flying over (Dead/No fly Zones) which Aviation Authorities are responsible in providing to the Airline companies so they can adjust their flight plans.

FAA Warning over flying over Crimea.

Planes Flight Path.


Circular arc airfoil wing: why does the wing nose down twist due to camber?

I think it may be related to the geometric construction of the blade :

Usually taper is made by scaling down airfoil at wingtip, which doesn't alter angle of attack at all.

In this case the airfoil itself is cut along a line going from root trailing edge to tip mid-chord, which alters angle of attack with desired negative twist.


Is it possible to upgrade an old F-16 to the Block-60/62 standard?

F-16D/E Block-60 is an evolutionary upgrade to the F-16A/B Block-15 with the following differences:

Engine: General Electric F110-GE-132 in place of Pratt & Whitney F100-PW-200 turbofan.
Avionics: This is where the majority of upgrades have been carried out. Block 60 has the AN/APG-80 'Agile Beam' AESA radar, AN/ASQ-28 IFTS (Internal FLIR and Targeting System) replacing the earlier external pods, ALQ-165 electronic countermeasures system, improved pilot displays, improved mission computer and ability to fire more weapons like AIM-132 and AGM-154.
The main structural modification is the addition of conformal fuel tanks in the wings, with slight change in dimensions and increase in MTO weight- 46,000lb vs 37,500 lb

F-16 Block 20, Image from f-16.net

F-16 Block 60, Image from f-16.net

Though it is possible to upgrade block 15 to block 60 (albeit with some heavy modifications), the question is why anyone one would do that. Even the youngest Block 15 aircraft is nearly 20 years old (the last aircraft rolled off the assembly line in 1996) and LM has shut down the F-16 production line. The upgrade will be costly (you're changing some of the costliest items in the aircraft- avionics and engines) and will not be cost-effective in an aircraft past half its service life. Also, as far as I know LM doesn't offer any upgrades from Block 15 to 60, indicating consumer indifference.


What is the purpose of long endurance test flights?

This particular test flight tested the engines, not the aircraft:

  At 15:38 local time N7874, the fourth 787 built, departed Boeing Field
  in Seattle for an 18-hour, 22 state test flight. The crew spent the
  overnight hours above the United States performing ETOPS testing on
  the new Rolls Royce Trent 1000 TEN engine, which will power the
  787-10.

https://www.flightradar24.com/blog/boeing-uses-a-787-to-draw-a-787-dreamliner-during-etops-test/


Cp, Cg and Np location of a tandem wing configuration, both have positive lift?

I understand that in a tandem layout, the Cp has to be ahead of the
  Cg, and the Np behind the Cg.

No. Yes.

For a true tandem (without horizontal tail), it makes little sense to talk about an isolated wing. The combined CP will always coincide with CG (in a static flight). Otherwise, as Jan already noted, the airplane will pitch up.

For NP (neutral point), see below.

  Is there a rule of thumb how far forward the Cp has to be in front of Cg?, like 17% to 33% of MAC, etc.

Forget about CP. It's useful in aerodynamics (and somewhat in structural design), but for the dynamics and stability analysis only NP matters. CP is very inconvenient, it moves all the time.

All these 'rules of thumb' apply to NP, not CP. In particular, the distance from CG to NP (CG being ahead) in terms of MAC is your 'static stability margin', and is the main contributor to static stability.

The rule is roughly the same regardless of the aerodynamic configuration. Some minor effects will be different (for example, damping will probably be lower), which may require some minor adjustments.

  Should Cm vs alpha, still have a negative slope?

For static stability, yes. This is essentially the definition of static stability; how you achieve this slope is another matter.

  Is it possible to have a 50% lift split between rear and front wings, just have a higher incidence in front wing, so it stalls first.

Yes. You'll normally need a somewhat smaller front wing for that. Or you can have a swept front wing and straight rear. Note that if you want a stable aircraft, at a higher angle of attack by definition the lift on the rear wing must rise more than on the front one. If you want to keep this AoA (e.g. at a lower speed), you'll need to dump this extra gain via re-trimming.


Do the engines still spool up when reverse thrust is selected, but the reversers are not deployed?

Although not exactly the same thing you're asking you might be able to surmise an answer about Airbus from what happened in the crash of TAM flight 3054.

It was an A320 landing in Sao Paulo with a known inop T/R on the right engine. The pilots retarded the left thrust lever to idle to engage spoilers and then into reverse to engage left T/R but left the right lever in CLIMB. The autothrust turned off and due to the lever positions the left engine went into reverse thrust while the right engine went into full forward thrust causing them to veer off and overrun the runway and crash.

According to Airbus this had been a problem before so they changed the procedure for single T/R. It was previously to bring both to idle then only the working one to reverse. This was apparently confusing the pilots causing accidents so they changed it. The correct procedure is now to bring BOTH levers to idle then at touchdown, BOTH to reverse. Obviously if this is the procedure the A320 will not normally spool up the engine that did not have reverse thrust. The only reason it did was because the pilot left the right lever in the climb detent.

I'm not sure if this is true if the T/R's were PREVENTED from deploying due to the wheels not touching down but I would figure it would.

The way the A320 thrust levers work is that you release a catch then pull the levers aftward past the idle detent. (Not a pilot so correct me if I'm wrong here) Other a/c have a separate set of levers, for reverse thrust, sometimes hinged to the main thrust levers.

According to this illustration I found at this site the DC10 did have such a system to prevent the thrust to be increased until the reversers were deployed.

According to a BEA investigation report the B747 has a similar system:

  The thrust reverser mechanism is commanded by one lever located on each thrust lever. In the ground position and when the thrust levers are at idle, it is possible to pull the thrust reverser levers back to the "interlock" position which corresponds to reverse. This unlocks the reversers and initiates their deployment. There is blocking in the interlock position when the reversers are in motion or incompletely extended. The use of full reverse thrust is possible when the "in transit" lights are off and the "unlock" lights are on (see appendix 2) to indicate that the reversers are deployed and locked. (BEA site)


Can the wing stagnation point be bled off and used for laminar flow control?

No.

Slow-moving also means low mass flow. In order to re-energize the boundary layer, the air has to move fast, meaning high mass flow. Also, speed means reduced pressure, so the stagnation pressure is not sufficient to produce that desired high-energy flow.

Also, contamination (bugs, ice) accretes close to the stagnation point. Ideally, in order to remove contamination, blowing would have to happen across the stagnation point. For that, blowing pressure needs to be higher than stagnation pressure.

The only use of stagnation pressure for boundary layer control is for tripping by blowing perpendicularly to the surface into the boundary layer. This works with low mass flows already.


What effect does tropopause entry have on the FMGC?

It adjusts the FMGC temperature model to account for non-standard temperature. This will have the effect of improving performance predictions by having a more accurate temperature model.

The FMGC uses a temperature model based on the International Standard Atmosphere (ISA). The ISA is based on a sea-level temperature of 15 deg C. In the model, temperature decreases with altitude at a rate of 1.98 deg C/1000 feet up to the tropopause. Above the Tropopause, the temperature is a constant -56.5 deg C.

Updating the tropopause as well as entering the cruise altitude/temperature will adjust the temperature model closer to actual and thus improve predictions. Not entering either value will result in predictions using the ISA model which will reduce the accuracy of predictions (except in the off chance the actual weather matches the ISA.)


What are Electro Hydraulic Servo Valves and Solenoid Operated Valves?

A solenoid is an induction-based actuator. In its simplest form it is a magnetic rod inside a coil of wire. Run a current through the wire and you create a magnetic field that creates a force on the rod, moving it one direction or the other. The force with which this occurs is proportional to the current through the inductor (audio speakers use this exact same principle to make the cone vibrate).

A solenoid-operated valve usually functions as a simple gate; the solenoid mechanism pulls or pushes a simple flat valve allowing the fluid to pass through or not. It's technically possible, but not usually feasible, to use a solenoid as a variable valve; for it to be accurate would require very low friction so the current applied to the solenoid (and thus the force on the valve) could be varied to produce smooth variations in valve position.

Solenoid-operated valves are typically used as triggers for larger mechanisms, including the electrohydraulic servo valve.

An electrohydraulic servovalve uses electrical current to move a "flapper", similar to a solenoid. The flapper controls the flow of hydraulic fluid to one side or the other of a spool valve. That moves the spool valve, allowing the supply pressure to feed an actuator cylinder, moving it one way or the other. However, that same movement also allows hydraulic pressure to return up to the flapper, providing a countering hydraulic force to the electrical force that moved it, called "negative feedback". Eventually these forces balance, and the flapper re-centers, closing the spool valve. The net result is that the actuator cylinder has moved a certain set distance, proportional to the strength of the input current.

These valves are used to provide smooth, high-strength motion in a hydraulic system. This type of valve, for instance, can be used to move the control surfaces of a large airliner, without requiring high-pressure hydraulic lines or tensioned cables to link the hydraulic system to the yoke in the cockpit. Instead, the yoke (or sidestick) controls the current through electrical wires leading to the EHSVs. That link is much easier to maintain (and cheaper to build in the first place) than older systems on previous generations of aircraft.


What is this plane shown on the 'Blended wing body' Wikipedia page?

Its a Rockwell B-1 Lancer a heavy bomber used by the USAF.

(source)


What does "traffic in position..." phrase mean?

The phraseology in the question is incorrect.

If the planes on on the same runway without ASDE-X, the aircraft departing will be given:

  DELTA 2-7, RUNWAY 1, LINE UP AND WAIT, BOEING 7-2 6-MILE FINAL

The arriving aircraft will not be given a landing clearance until the holding aircraft has departed, but it will be told:

  AMERICAN 4-2-9, RUNWAY 1, CONTINUE, TRAFFIC HOLDING IN POSITION

If the planes are on different runways, it would be:

  DELTA 2-7, RUNWAY 1, LINE UP AND WAIT, TRAFFIC LANDING RUNWAY 19

and the other

  AMERICAN 4-2-9, RUNWAY 1-9, CLEARED TO LAND, TRAFFIC HOLDING IN POSTION RUNWAY 1

Source: Air Traffic Conrollers Handbook, Section 3−9−4. LINE UP AND WAIT (LUAW)


Are four-engined airplanes calibrated to put out the same thrust for both their inner and outer engines?

If the fuel control is hydromechanical (old engines) or electronically trimmed hydromechanical (not so old engines designed in the 70s and 80s), you set each thrust lever to achieve a target value on the fan RPM (N1) indicators or Engine Pressure Ratio indicator (EPR) indicators (for a pure jet).  Each engine will be set to its takeoff thrust setting, which should be the same for each since they are all the same model, but the thrust levers may or may not quite line up due to mechanical and other tolerances (there are limits).

On some modern airplanes with Full Authority Digital Engine Control, you move the levers to a detent setting, usually one for climb and one for take off, that is created by a roller running in a track inside the quadrant for each lever, that drops into a dip in the track; you can feel it click into place.

For takeoff you push them up through the climb detent to the takeoff thrust detent, so it's "click click". That position tells the FADEC computers to set takeoff power and the levers will all be perfectly lined up, the position being a function of the detents in the quadrant.  Of course, if it's got an autothrottle system, the computers take care of moving the levers as well.

In any case, the thrust settings for each engine should be the same, unless the airplane had engines with different thrust ratings inboard and outboard for some reason, and which would be an unpopular feature with most airlines.  I'm not aware of one.


Is this blended wing body trijet airliner real?

It is a blended body design. It is a hoax.  See similar photo from Popular Science magazine 2003 on wikipedia page: https://en.wikipedia.org/wiki/Blended_wing_body

By Source (WP:NFCC#4), Fair use, https://en.wikipedia.org/w/index.php?curid=37713174


Is it legal to carry medical oxygen on an aircraft for a passenger?

FAR Part 135.91 notes that medical oxygen containers - whether for the storage, generation, or dispensing of oxygen - must be:

135.91.a.1.i Of an approved type or in conformity with the manufacturing, packaging, marking, labeling, and maintenance requirements of title 49 CFR parts 171, 172, and 173, except §173.24(a)(1)
135.91.a.1.ii When owned by the certificate holder, maintained under the certificate holder's approved maintenance program;
135.91.a.1.iii Free of flammable contaminants on all exterior surfaces; and
135.91.a.1.iv Appropriately secured.
135.91.a.2 When the oxygen is stored in the form of a liquid, the equipment must have been under the certificate holder's approved maintenance program since its purchase new or since the storage container was last purged.
135.91.a.3.i-ii When the oxygen is stored in the form of a compressed gas as defined in title 49 CFR 173.300(a) When owned by the certificate holder, it must be maintained under its approved maintenance program; and The pressure in any oxygen cylinder must not exceed the rated cylinder pressure.
135.91.a.4 The pilot in command must be advised when the equipment is on board, and when it is intended to be used.
135.91.a.5 The equipment must be stowed, and each person using the equipment must be seated, so as not to restrict access to or use of any required emergency or regular exit, or of the aisle in the passenger compartment.
135.91.b No person may smoke and no certificate holder may allow any person to smoke within 10 feet of oxygen storage and dispensing equipment carried under paragraph (a) of this section.
135.91.c No certificate holder may allow any person other than a person trained in the use of medical oxygen equipment to connect or disconnect oxygen bottles or any other ancillary component while any passenger is aboard the aircraft
135.91.d Paragraph (a)(1)(i) of this section does not apply when that equipment is furnished by a professional or medical emergency service for use on board an aircraft in a medical emergency when no other practical means of transportation (including any other properly equipped certificate holder) is reasonably available and the person carried under the medical emergency is accompanied by a person trained in the use of medical oxygen.

Part 91 does not seem to speak to medical oxygen
Additionally, a page on the FAA website notes that:

In the DOT final rule, section 382.133 generally requires that air carriers conducting passenger service must permit someone with a disability to use an FAA-approved portable oxygen concentrator (POC) on all flights (on aircraft originally designed to have a maximum passenger capacity of more than 19 seats) unless the device does not meet applicable FAA requirements for medical portable electronic devices (M-PED) and does not display a manufacturer’s label that indicates the device meets those FAA requirements.

The page goes on to list approved oxygen containers. So, it seems that the FAA does not consider POCs to be hazardous, so long as they meet certain FAA approval standards. (If you are asking about General Aviation requirements, I would assume an FAA-certified POC is okay to bring on a GA flight as well)


Why do some back course operations use normal sensing?

Notice that in the plan view, the shading of the localizers are on the opposite sides. If you are flying south-west, the actual localizer used for the approach has the shading on the right, while the one used for the missed approach has the shading on the left. This can also be used to tell you what sensing to expect.  The note is also there to make it more obvious that the sensing will be backwards from what you might expect when flying outbound on a "normal"  localizer.

So yes, this particular localizer is designed to transmit backwards and you will get indications that would be normal while flying inbound when flying outbound on the missed.

I'm guessing that because of the high terrain/mountains in the area that they wanted to make it as easy as possible to fly without getting confused as to which way you are supposed to turn.  Combined with the fact that it is never used in a situation where you would be flying inbound makes it a perfect candidate to reverse the sensing.  Unfortunately, in my mind it actually makes it harder to understand.  We are taught from the beginning of our instrument training how to handle flying a localizer outbound, and now we have to do it the opposite way.  Rather confusing if you ask me, but you get used to it.

As far as "how common is it", this is the only one that I've seen (but I'm guessing that there are others)....


High altitude means low air density. Ignition is harder to achieve with lower density, and the size of the combustor determines up to which altitude and throttle setting an engine will stay lit. Testing that it really works at those low densities before flying is a really good idea.


Why is thrust vectoring not used on commercial jets?

Thrust vectoring is for flying outside the "normal" envelope (which is characterized by attached flow). Airliners should really never leave this envelope, so they are perfectly fine with regular control surfaces.

If you want to add thrust vectoring, it would make most sense if the engines are at the back of the airplane. On most airliners, it is really better to put them on and ahead of the wings, because in this location they help both with flutter damping (mass ahead of the elastic line helps) and bending relief. Putting the engine mass right where lift is created is better than carrying stresses all around the airframe, which would be the case with rear-mounted engines.

The redundancy point is valid, but it would be more helpful to have redundant control surfaces, and this is exactly what airliners have. At some point, every airplane has to come down for a landing, which requires to throttle the engines. No thrust, no control!

Most extreme case: If one tail surface breaks off, I wonder if thrust vectoring would be up to the job of trimming the aircraft even with cruise thrust. Not only have the raw forces to be sufficient, the reaction time to control setting changes has to be quick enough to suppress oscillations. I am sure, however, that thrust vectoring will certainly not suffice in all flight phases.

Thrust vectoring is perfect for situations at high angle of attack where you quickly want to point the nose of your aircraft at your adversary, so you get lock-on first. This is quite different from what an airliner has to do.


What are acceptable treatments for chronic pain that will not result in a loss of an FAA Medical?

The only real answer here is to consult an AME. I searched on the AOPA forums (members only) and the information wasn't encouraging: all current (as of 2014, which was the more recent relevant post I found) neuropathy drugs are disqualifying. AOPA's list of approved drugs does show some approved drugs for pain relief, but it looks like it's all OTC stuff.

But, the usual medical disclaimer applies here: every case is different so the above may be irrelevant to you personally; I'm not a doctor and I don't know what I'm talking about anyway; only an AME can give you meaningful information.


Is there a tool to learn to pronounce aviation jargon accurately?

With the exception of abbreviations (like FSDO, pronounced fizz dough) there's not much "jargon" in aviation that's not a standard word in whatever language you're speaking. Words like "dihedral", "anhedral", "aileron", etc. should certainly show up in a dictionary.

The abbreviations are "tribal knowledge" the same way they are in any other field (e.g. SCSI, SATA, IMAP in the tech field). I'm not aware of any authoritative compendium of pronunciations.


How to find TAS for given CAS, FL and OAT?

My trusty E6-B flight computer (I can't believe we still teach people to use what is essentially a slide rule) has the following printed on it:

AIRSPEED CORRECTION
Set PRESS. ALT opposite °C in window. Opposite CAS on inner scale read TAS on outer scale. Read Density ALT Centre ▲

Following the instructions and setting -15°C against 8,000 ft reads a TAS of 170 kts for a CAS of 155 kts


What is it like flying in class B airspace?

On my first cross-country as a student (dual), we actually transitioned through the class B airspace just north of us, flew to a smaller airport north of town, did a landing there, followed by flying back to the class B and landing at the primary airport there before returning home.

Basically, I had a few key experiences:

The controllers work quickly and expect you to pay attention.  More than once, as a rather inexperienced pilot, my instructor had to help with the radio, either in understanding the instruction, or helping reduce my confusion by handling communication.
Even on a slower Sunday, the center was training a new controller, so there were times the person training had to step in to clear up some of the radio congestion -- we almost had to turn away from the class B, since they hadn't yet assigned us a beacon and cleared us through the bravo.
We got vectored around pretty quickly... which, basically threw out all our flight planning (we were expecting this to happen anyway).
Talking to approach to land, they told us to expect the visual approach to one of the parallel runways, and the tower controller didn't toss us any curve balls there.  Although, with the headwinds, even with a fair amount of power, we weren't moving very quickly, and probably got cleared to land a bit too early (thankfully, the airspace wasn't busy... but there were a few jets waiting for us to land and taxi off).
Ground control and clearance delivery was combined, and they were pleasant enough to give us progressive taxi without asking (I was expecting to write furiously), and also let us taxi to depart off the intersecting runway.
Departing after cleared and returning home was pretty uneventful.  At this point, I was out of the way for most traffic.  Much more like being under regular flight following.

Granted, it's not like I was flying into ORD -- it was a pretty slow day at an airport that isn't busy much to begin with -- but I have a feeling if you've been used to flying from a Class C airport, not much will feel different for the most part, especially at one of the smaller Class B airports (and for the bigger ones especially -- DEFINITELY get to know the airport diagram beforehand).

To answer some of your specific question, the A/FD will list traffic patterns (probably going to be opposing right/left traffic for parallel runways so people don't end up head on at each other) ;) Controllers will guarantee separation from all aircraft, so you'll be assigned a heading and altitude (maybe "at or below"), and possibly a speed.  So really, if your radio communications are good and you're able to fly straight and level, you won't have many problems (it just comes down to obeying clearances, and not violating any airspace).  You're right that you would need an endorsement to fly solo into a Class B airspace, but this would not apply if you were dual with your instructor, since they are PIC.


Can transition on an airfoil occur without prior separation?

can transition occur without the presence of a laminar separation
  bubble?

In short YES.
To elaborate, there are usually 3 mechanisms causing the boundary layer to go turbulent.

Natural transition
Forced transition
Bypass transition

Because the question is about the Natural transition; this is usually caused by sufficiently amplified Tollmien–Schlichting waves. The reason why you see a transition followed by separation in low Reynolds number flow is because in the separated flow, the amplification factor is around 4 times as much as for the attached flow.

  If yes, what would this look like in a pressure distribution?

  Here, a clear laminar separation bubble can be seen. The Reynolds
  number has been increased by a factor of 10. The transition point is
  still visible, but it is not so clear anymore whether there is a
  separation bubble. Is there a possible scenario where a laminar
  boundary layer transitions without first separating?

As indicated above, it is possible for a boundary layer flow to make the transition to turbulent without separation.
N-factor growth rate scales as $\sqrt{RE_\infty}$ for attached laminar flow and for sufficiently enough $RE$ you can easily see the transition undergoing without any separation.

Also, it's best to inspect the boundary layer parameters through the VPLO menu which gives a clear indication on whether the flow is actually attached or separated.

A very good reference for this is Prof Mark Drela's Flight Vehicle Aerodynamics. - Chapter 4.


Can a plane with 2 sets of shorter wings fly?

What you are proposing is called a "tandem wing", and it's been done before. A brief search should produce more than enough research papers about the advantages and disadvantages of this particular design.

The near-complete absence of multiple-wing designs in modern aviation should be a hint that the design has issues. Unless you particularly need the advantages of the design more than the drawbacks, there's no particular reason to use it.


How does a dispatcher assign relative costs to trajectories in TOS?

[The] TOS options include defining preferences with regard to:

  Route: The Flight Operator may route out of a CTOP FCA into another CTOP FCA or out of the CTOP altogether. Submissions should conform to standard flight plan requirements (i.e. NRP, required reroutes, preferred routes, etc.).
  Altitude: The Flight Operator may file different altitudes, thereby changing the assigned TOS option.
  Speed: The Flight Operator may file different speeds, thereby changing the assigned TOS option.
  [Relative Trajectory Cost]: The Flight Operator may file different RTCs, thereby changing the assigned TOS option.
  TVST/TVET: The Flight Operator may file different TVSTs/TVETs (start/end times), thereby changing the assigned TOS option.
  RMNT: The Flight Operator may file different RMNTs, thereby changing the assigned TOS option.

Source: AC No: 90-115

For example, if they change only the route, the distance will change, and so would the average winds, and thus a new air distance estimate. It could be longer or shorter. The airline may also change the speed, flight level, etc.

Calculations are most certainly computerized but with human input/decision. It could be made either by using proprietary software or commercial flight planning solutions.


Why did the Junkers Ju-52 have corrugated external surfaces?

It was largely a structural decision. The Ford Tri-Motor which was designed to mimic many things the Junkers plane designs included, including the corrugated metal.

  ...all of which were constructed of aluminum alloy, which was corrugated for added stiffness, although the resulting drag reduced its overall performance.

Corrugated metal is common for roof panels and ironically, hangars, these days. You can find some info on the strength and flex properties of it when related to those topics. Here is an interesting thread on increased drag (and load) on corrugated roofs.

As for the availability of the material vs sheet aluminum I would argue that it had little effect on the design choice. Keep in mind all corrugated aluminum starts out as sheet aluminum at some point in the line so its hard to say there is more than one or either material. On top of that it takes more corrugated material to cover a specific square area than flat sheet material which would drive the price up. At that time period in aviation a lot of experimenting was going on and anything that made a plane a bit stronger or a bit faster was considered quite an achievement. Keep in mind we are coming of the tails of the fabric plane era so a design like this would have seemed revolutionary. The Ju-52/3m (the one you have pictured) came out in 1932 (work began in '28), by that time other makers were already looking at and working on smooth aluminum body planes. There is of course a large social aspect to the availability of materials at this time in history especially in Germany. I will refrain form a full history lesson here but you can read up on Junkers history here and about the man him self Hugo Junkers here which include some of his political views and his involvement (and issues with) the Nazi party. His work in all metal designs is credited with inspiring many passenger planes in the post WW1 and WW2 eras of design.


What is the wing angle of attack of a Boeing 737 in cruise?

First, let's assume that all lift is created by the wing, and that the plane is flying in ideal conditions, where fuel flow per distance flown is minimal. This point is given by $$c_L = \sqrt{\frac{1-n_v}{3+n_v}\cdot c_{D0} \cdot \pi \cdot AR \cdot \epsilon}$$ Please see this post for more background on this formula.

Nomenclature:
    $c_L \:\:\:$ lift coefficient
    $n_v \:\:\:$  thrust exponent, as in $T \sim v^{n_v} $
    $\pi \:\:\:\:\:$  3.14159$\dots$
    $AR \:\:$  aspect ratio of the wing
    $\epsilon \:\:\:\:\:$  the wing's Oswald factor
    $c_{D0} \:$  zero-lift drag coefficient

The $n_v$ I would estimate to be -0.4, the $c_{D0}$ is somewhere around 0.016, the aspect ratio can be taken from this source and the Oswald factor is 0.8. This gives you an optimum lift coefficient of 0.445. Now we need to know what angle of attack is needed for this lift coefficient. If we look at the midspan airfoil of the 737, this angle of attack is around 2.8 degree.

This source is for model airplanes, so their Mach and Reynolds numbers are much too low for the real thing, and we need corrections for both. Using the Prantdl-Glauert rule for Mach effects, we need to correct by dividing with $\sqrt{(1-Ma^2) \cdot (1 + tan\varphi)}$ = 0.693 at Mach 0.82. Please note that this increment must be applied to the zero-lift angle of attack, which is -1°. Now our angle of attack is only 1.63°. The flight Reynolds number of the 737's MAC is 22 million, so the angle of attack is even less, maybe 1.5°. Now we need a correction for the 737 wing sweep of 25 degree, which is computed by dividing the angle of attack by 0.9, the cosine of the quarter chord sweep angle. This gives about 1.8° as the corrected value.

So my quick-and-dirty answer is 1.8 degrees. Other sections of the wing have slightly different values, according to the wing's twist. Please note that the wing area of the 737 is roughly constant since the Sixties, while the mass has increased considerably. It is safe to assume that it is operating at higher angles of attack than the optimum for best range.


Why don't airships / blimps use frontal stabilizers or thrusters?

It depends if you want stability or manuverability. see this video.

It also has to do with if you want to attempt to keep laminar flow over the nose of the airship...


Can an Indian operator get approval for ETOPS-120 without first getting approval for a lower ETOPS rating?

The short answer is yes (unless the DGCA has some unusual process with no public documentation). But be careful: the manufacturer does not certify an aircraft for ETOPS; only a regulatory agency can do that. The manufacturer can put in its books what it thinks is possible/acceptable, but without approval from the local regulatory authority, an operator cannot legally use those books for continued airworthiness. Generally, though, the big manufacturers work with the big local authorities worldwide to make sure that the books will pass muster internationally. But that does not mean that individual operators are exempt from needing to obtain local certification for their specific operations and airplanes. Given the basis you've listed, an operator would have a very strong case, in my opinion.


How does static port measures the static pressure?

Your friend is correct. It's situated in a spot where the dynamic pressure is non-existent or minimal such as on the rear side of the fuselage on a Cessna 172 where it's able to measure the ambient pressure. This pressure is then either fed by tubes to their respective instruments (ASI, Altimeter, and VSI), or on modern aircraft, it is read by a transducer (or analog to to digital interface units - A/DIFU) which converts the reading to electronic data which is then fed to the air data computer.


Why are the best glide and best range airspeeds different for a C172?

Maximum range depends not only on the variation of lift to drag versus airspeed, but also on the efficiency of the engine and propeller versus airspeed. The C172's fixed pitch prop, fixed ignition spark advance timing, fixed valve lift and closure timing and other characteristics all have effects on the miles per gallon attained at different indicated airspeeds along with the lift to drag of the airframe.


When are flight tracks publicly available?

Skimming FlightAware's FAQs:

The most consistent way to show up on FlightAware is to have your flight worked by ATC (a squawk code and an IFR flight plan), or to fly an airplane equipped with ADS-B Out.
FlightAware doesn't really track VFR flights unless they have ADS-B Out:

  some VFR aircraft with flight following are available on the position maps but it largely unreliable

  You can block your tail number in a few ways. Both the FAA and FlightAware operate block lists.


Why do English-speaking pilots and ATC say "Niner" instead of "Nine"?

According to Wikipedia:

  The pronunciation of the digits 3, 4, 5, and 9 differs from standard English – being pronounced tree, fower, fife, and niner. The digit 3 is specified as tree so that it is not pronounced sri; the long pronunciation of 4 (still found in some English dialects) keeps it somewhat distinct from for; 5 is pronounced with a second "f" because the normal pronunciation with a "v" is easily confused with "fire" (a command to shoot); and 9 has an extra syllable to keep it distinct from German nein 'no'.

The phonetic alphabet is not a random selection of words. It was created very carefully taking dialects into account, so as not to confuse any of the letter with possible mispronunciations. Although they are "English" words, the choices were made with the world in mind.

As mentioned on the same article:

  The final choice of code words for the letters of the alphabet and for the digits was made after hundreds of thousands of comprehension tests involving 31 nationalities.


What factors should be considered when taking private pilot renter's insurance?

Ignoring what you should and should not have in terms of coverage for your self there are some facts to note about getting gap insurance.

You need to speak with your flight school and ask them what they require you to have as every flight school could be insured differently. For example, when I got my renters insurance I had to have 10K of aircraft damage coverage as the flight schools insurance did not kick in until then. Had anything happened I would have been responsible for the 0-10K worth of damage. In this case you would want coverage for damage to the aircraft. If the flight school has insurance on any and all damage you may not need it on your insurance.


Is there a formula for calculating the pivot point of an aircraft while turning on the ground?

The pivot point will be where an imaginary line through the rear wheels and an imaginary line perpendicular to the front wheel intersects.

So if θ is the steering angle and d is the distance between the front wheel and a point halfway between the rear wheels then

X = d • tan(θ)

will give you the distance from the point between the rear wheels to the pivot point.


Can an FAA-certified pilot rent/fly a GA aircraft in England?

You can rent a G-registration aircraft but your license will be treated as a UK private pilot ticket with day VFR privileges without any additional paperwork so long as you stay in UK airspace. There is a basic requirement to file one form, and you must get a signoff on simple theoretical knowledge, but that is it for now. See this CAA Information Notice for additional details.


Am I correct about what AC/DC BAT BUS does?

You can't easily link the two AC buses together, you'd need to synchronize the phases first. And then a short on one side could cause a complete failure so you'd have to isolate them again. Way to complicated to get that failure tolerant. Instead they just use two independent AC systems. Generally each system exists twice and each one gets a different power source.

In the A320 you have two main AC buses (AC 1 and AC 2) in flight these are powered by engine 1 and 2 respectively. And there is a AC essentials bus, which is either connected to AC bus 1 or if that bus is unavailable it is connected to AC bus 2. The AC essential bus can also get power from the DC essential bus via essential transformer. So you can run the captain PFD and ND and the upper ECAM on battery power (only available above 80kts or sth. or in the air - for emergency only)

Check out the A320 "electrical system descriptions" and "indicating and recording" http://www.smartcockpit.com/plane/AIRBUS/A320.html

At the bottom of the indicating/recording systems you have a bus equipment list telling you exactly which consumer uses which bus. This is true for all other sections as well, so if you are interested in a particular system you can quickly find out where it is powered from.

According to A320 FCOM, 1.31.75 Indication/Recording Systems, Electrical Supply, Bus Equipment List

  AC ESS bus powers the captain PFD and (via AC ESS SHED) the captain ND, the upper ECAM screen, the display management computer (DMC) 1 and
  3 (if selected and AC1 failed), flight warning computer (FWC) 1 and SDAC1. (and many many other things ...)
  AC 2 powers F/O PFD, ND, lower ECAM, DMC 2, FWC 2 and SDAC2 (...)
  AC 1 powers the DMC 3 normally (...)


How to get out of icing conditions asap?

well, you'd have to fly in whatever is the shortest route out of the icing conditions, obviously.
What that would be depends on your speed, wind, climb/descent performance, and how you entered icing conditions.
If you entered icing by climbing, diving may well get you out of it (but if you were climbing to avoid terrain...).
If you were turning left, turning right might do it (but were you turning left to avoid collisions?).
Etc. Etc.
IOW there's no universal answer, it's way too situational.


What are the indications that your turbofan engine has "thrown a blade?"

Turbofan engines are designed and tested to contain a fan blade failure. However, this is a violent event and will cause serious damage to the engine. The engine and surrounding components are subjected to large forces and vibrations, and the engine can ingest debris from the damage to the fan, causing further damage. There will likely be an investigation, and the engine will probably be scrapped due to the widespread damage to different components.

To the pilots, it will seem like a bird strike, but probably worse. There will be a loud noise as the fan blade separates and collides with the fan case and following blades. The fan will then be out of balance, so heavy vibrations will follow as the shaft loses its rotational energy. The pilots will be able to tell which engine has failed by the loss of thrust, as well as the indications of vibration and failure on the instruments for that engine.

If the fan does not get stuck, it will continue to windmill, which will result in ongoing vibration from that engine.


Short answer yes, a powered aircraft at any given airspeed in straight and level flight (note that a glide path is also "level", at constant airspeed) needs to use the same amount of energy to over come drag as the glider.

The potential energy for the glider is altitude. The potential energy for the powered aircraft is fuel.
The conversion of potential energy to kinetic energy gives the aircraft velocity and matches drag forces.

There for, gliding is powered flight! They might "fill up" by catching a thermal, or by having someone tow them up.


Why do privater jets often fly at or above FL 400, but large commercial aircraft are usually in the range of FL 300 to FL 400?

FL360 (plus or minus a bit) is the optimal altitude for fuel efficiency, which is the top priority for airlines. And airliners all fly at roughly the same speed (again, for fuel efficiency), so ATC can just line them up in a row and let them follow each other.
The problem is that level is severely congested with all those airliners. You can’t really get out of line or pass someone, which is another reason they’re all flying the same speed—and that has become a vicious cycle because Boeing and Airbus now design their planes to be most efficient at that speed.
Business jets passengers (and thus their operators) value speed over efficiency; if they didn’t, they’d use much cheaper airline flights. However, to avoid the airliner congestion around FL360, they have to climb to FL400 or higher, where they can fly faster and likely get a more direct route.


Why did my flight descend for landing then suddenly climb steeply and turn sharply?

According to data recorded on Flightradar24 and the Planefinder App, that particular flight did not go around; however the turn to final approach was flown at lower altitude than some other flights that day (this seems different but not necessarily uncommon or abnormal, and happened for unknown reasons that cannot be inferred from the data).

Screenshot from the app:


What is the correct formula to calculate propeller efficiency?

Propellers are designed for an optimal tip speed being a certain multiple of the air speed they are flying inside. The angle of the propellers aerofoil shape to the propellers axel changes as you move from the Center to the tip. The more pronounced the blade rotation the higher the intended tip speed.

From memory having the tip speed running at 1-3 times the the air flow speed is not efficient, but at least the propeller works over a wide range of air speeds.

Highly tuned propeller tips are moving at 6x the air speed. However, their effectiveness at moving air disappears rapidly if the air flow is too slow. (The propeller blades are stalled)

The last thing you want on a propeller plane is an efficient propeller.


Is there a way I can find out online what private jets are parked tonight at a nearby international airport?

There is not simple list available online, apart from calling the airport and asking them directly. Aircraft are expensive assets so when people own them they tend to keep them under the radar and out of sight and out of the elements by parking them inside a hangar. As an outsider you can only see the outside parked aircraft from the airport fencing.

Determining which aircraft are parked for a short term on an airport is relatively simple to find with the use of an aircraft tracking site such as FlightAware and FR24. On these sites you can enter an airport and see all the official flights in and out of that airport. Flights that have landed but not yet departed will be parked somewhere on the airport.
For example, Lubbock Executive Airpark (Lubbock, Texas, USA)
https://flightaware.com/live/airport/F82/arrivals

Starting from January 2020, the FAA dictates that all airborne flights in the USA should be equipped with an ADS-B transponder, when inside ADS-B airspace, used by the sites above and air traffic control to track flights. So from that day the tracking of smaller aircraft will be greatly improved.


What is the difference between saturated and unsaturated adiabatic lapse rate?

The difference between a unsaturated and a saturated adiabatic lapse rate is that in the latter the water vapour has to change state from gaseous to liquid.
When air rises it expands due to the lower pressure of the ambient air at higher altitude. By expanding, the air parcel is doing work on its surroundings. Since no heat is transferred to the air parcel (by definition of being adiabatic expansion) but work is being performed, the temperature has to drop. Thus a rising parcel of air cools down.
Cooler air can hold less water vapour than warmer air. If the air parcel contains water vapour, at some point during the cooling the maximum relative humidity is reached. At that point the air is saturated with water vapour. If the air continues to cool, the water vapour content has to change from vapour to liquid. This is called saturated adiabatic cooling.
The process of condensation of the water content is exothermic; when the state changes from gaseous to liquid, heat is released to the air in the parcel. Therefore the lapse rate (temperature change with altitude) of a saturated adiabatic process is less than an unsaturated adiabatic process. The heat released from the condensation process reduces the lapse rate.


Besides the main points you mentioned, I can think of a couple things, the first is sort of related to your point #1.

Airplanes are designed to be easy to service. Cars are less so.
Cars only have a few very expensive parts, mainly the drivetrain (engine and transmission). If either of those needs to be replaced in an older car, it can easily cost more than the car is worth.

Airplanes are much more complex, and have a larger number of expensive components. The engines of most airliners are designed to be removed relatively quickly. Although the engines tend to be the most expensive part, replacing an engine is nowhere near the total cost of the airplane, and there is generally a good pool of engines out there for parts and replacement (just look at how many JT8D engines are still in service).

In GA aircraft, it is easier for a repair to cost more than the airplane is worth. However, the more comprehensive maintenance required on aircraft means that this kind of repair is less likely to be needed. Also, while its usually easy to go out and replace a broken car with a comparable new or used one, the aircraft market isn't as large. New aircraft tend to be much more expensive, and the used market is more limited.

Another reason is that airplanes can have more unique qualities than cars. For example, there are original 737s flying in Canada because they are able to operate from gravel runways. There are just more combinations of sizes and capabilities in airplanes than with cars. Many times, it is only economical to replace those aircraft (both for the builder and the buyer) in very long cycles.


What is the relation between hinge moment at the control surface and servo torque?

The servo torque depends on the mechanism. If it has a gear ratio of 1, they will be equal. If the servo is driving larger angular deflections than its own, the servo torque will be higher.

Another important point is to consider the dynamic forces. XFOIL only computes results for steady conditions. Dynamically, the servo may have to bear even larger torques; due to acceleration or gravity.

Finally, unless you really trust your computations, some uncertainty factor can be used to reduce the risks of redesigning the control system solution.


What will the pilot do if all the airspeed indicators fail?

Some aircraft have angle of attack indicator, but most don't even though they have the sensor and use it for stall warning.

What you normally have is an unreliable airspeed procedure. This generally says that you should, depending on phase of flight, maintain specific pitch, set specified thrust and then adjust for rate of climb/descent while keeping the pitch.

Since aircraft is trimmed for speed, generally the procedure calls for being light on controls and correct mainly with engines. Exception is Airbus which keeps auto-trimming even with speed disagree warning on, so there side-stick controls climb and power controls pitch almost independently.

See also unreliable airspeed procedure for A330.


Are there any characteristics of a hypoxic flight?

If a "ghost" airplane with passed out pilots is unattended and the engines flame out, what is likely to happen is it will fly along on autopilot until one engine flames out a few minutes before the other. This will impose a pretty large amount of yaw, which the airplane's yaw damper may or may not have enough authority to counteract.  Yaw dampers generally can move the rudder somewhere around 1/3rd of normal travel and aren't meant to cope with asymmetric thrust (I recall from recurrent training in the CRJ that a flameout in cruise still required more rudder than could be applied by the YD to keep it flying straight and you still had to get your feet on the pedals post haste).
With the one engine dead, the yaw damper will be at full travel trying to "center the brick" (the little box shaped skid indicator on the Primary Flight Display), and if that's not enough, the airplane will be skidding along trying to roll into the dead engine, and the autopilot will be applying aileron to try to keep the wings level, and the airplane will fly along cockeyed, like happens when a new pilot on the type course experiences his/her first engine cut and forgets about their feet.
The amount of aileron may cause the autopilot to kick off at some point, at which point the airplane will immediately roll off toward the dead engine into a spiral dive (they won't just dive straight down, they have to roll off to one side into a spiral where the airplane's natural speed seeking pitching tendency just causes it to wind up the turn tighter and tighter as it goes steeper and steeper and faster and faster).
Or, if the autopilot is able to hang on, eventually the other engine flames out, the ram air turbine drops, most electrical services are terminated except emergency ones and the autopilot is likely to kick off then.
At that point, if the airplane is trimmed nicely and the air is smooth, it will likely simply descend more or less straight at its existing trim speed in a straight ahead glide... until something disturbs it, like a bump that makes it bank a bit more than dihedral effect can accommodate.
At that point most airplanes will drift off slowly into a descending spiral. It will turn steeper and steeper and descend faster and faster, either until bits start to come off the airplane from overspeed/over G, or it hits the ground (bits raining from the sky following spiral dives is what usually happens in GA disorientation events in instrument conditions - think Kennedy's crash).
So in the end, one of two things will happen.  If the airplane was trimmed at 240kt indicated, it will fly into the ground straight ahead descending at 240kt, or, if it got bumped into a spiral, it will come nearly straight down at close to Mach, making a small crater, or come down in individual pieces after breaking up on the way down.
And ending like the Lady Be Good is unlikely with a jet.


Do glider pilots require normal headsets?

No, but a hat to protect the head from the sun. You may call this the glider pilot's headset ;-)

Glider pilot with hat (picture source)

The flight noise is just a faint hissing sound, and the most noise is either produced by the electrical variometer or the radio. On a busy day and with everyone on the same frequency, I often switched the radio silent when high up. When you receive transmissions from tens of kilometers away, you often receive parallel transmissions, which result in a very loud and annoying crackling in the radio.


According to https://www.airliners.net/forum/viewtopic.php?t=241063 (and others) B73W is a newer version of Boeing 737-700. A one with winglets installed.
So, it's not B737 MAX 8.

A more comprehensive list (which sadly does not include 73W) is here What is the difference between Boeing 73G, 73H and 737?.


Why was Energy Maneuverability theory not applied to the F-14?

The Energy Maneuverability theory is primarily a conceptual design framework. Its role is to be a guideline in creating the requirements for your aircraft.

This is something well above the manufacturer's level of responsibility. The requirements are created by the buyer, like the US DoD; the manufacturer's job is to design a machine to meet them, with some leeway. And not all modern fighters are based on the E-M theory.

It's not impossible to use a new design framework if you were doing a Hornet to Super Hornet kind of 'Hollywood remake'. But otherwise, an aircraft is created to do a job, and that general job persists through upgrades. Every design choice is a compromise; to get more of X, you need to lose some of Y. Only with a major technological leap could you fit more of X without that loss.

The F-14's job was to maintain long-range CAP around the CVBG. It needed to detect incoming Soviet aircraft at the longest possible range and intercept them before they could launch their missiles.

The USN had very good reasons to dedicate their top fighter to this role. While the Soviet Navy (VMF) has never been a force the USN had to reckon with, the Soviet Naval Aviation (AVMF) has. Its workhorse was the Tu-22, a supersonic bomber with AS-4 missiles; they're large enough to take out a carrier, and, impacting at Mach 3.5-4.5, outside the realistic capabilities of contemporary SAM, AAM and CIWS to intercept. With a standoff range of over 300 nmi, AVMF bombers would be out of the reach of the Californias at the time of launch. This left CAP essential to carrier survival.

For this job, a fighter needs several things. It needs the range and endurance to patrol far enough from the carrier to help. It needs a powerful long-range radar to spot it before launch. It needs good supersonic speed to have a shot at a Mach 1.8 aircraft. It needs to carry heavy long-range missiles to reach the target.

You'll notice that dogfighting a Mig is not on the list above. It's certainly within the F-14's role, just not as critical as fleet air defense. Attack roles in the 1970s have been mostly filled by Skyhawks, Intruders and Corsairs. The F-14's design, including its swing wing, was a product of its high speed interception requirements, combined with low-speed needs of taking off with limited power and maintaining long patrols.

Even if the E-M theory was fully developed and accepted at the time, it's not likely that following it would have improved the F-14's performance without compromising its primary role. With the end of the Cold War the requirements changed, freeing up the F-14's carrier slots for multiroles with an offensive focus.


What does the Airbus A340 Primary Flight Display look like during startup?

Initially, I would like to apologize for the not-so-good quality of the pictures (there were taken into a busy enviroment).

I tried to find some vector photos from the respective manuals but I couldn't, that's why I took them by myself.

I am going to provide you with some information on each photo. It is very synoptic description in order to get the help you need for the development of your stuff, and to cover this question.

In case that you need any further technical information please open another question.

  1) Immediately after provide the a/c with power.

  2) After 40s

  3) After approximately 50s and before initialization of the ADIRS (which is taking place at cockpit preparation after the preliminary cockpit preparation checklist.)

  4) Approximately 15s after the startup of the ADIRS, and during the "IR alignment in progress." (info* on ECAM)

  5) During IR alignment in progress. (Only here the FDs are by default ON when the a/c is powering up, and the red FD symbol on the PFD during alignment is flashing, then manually FDs are switched off.)

  6) After IR alignment and before FMGS PERF PAGE preparation, (and FDs still are OFF).

  7) FDs are ON, FMGS preparation at PERF PAGE not completed yet, and ENGINES are OFF.

  8) FMGS PERF PAGE data inserted, FDs ON, ENGINES OFF.


What are the best traffic pattern airspeeds in a Cessna 172N?

This is really something you should discuss with your instructor, but if you want some general guidance then this should work:

Downwind: 70kts, 10° flaps
Base: 65kt, 20° flaps
Final: 60kts, 30° flaps

I say "guidance" because you may need to adjust this but it is in line with the POH values that you quoted in your comment and FWIW it's what I would use 'by default' in an unfamiliar C172. Although personally I wouldn't use 40° of flaps unless it's a short-field landing: the aircraft will come down more quickly with them fully extended.

But I'm not an instructor and I don't want to make assumptions about what he's teaching you and why, so you should definitely ask him this question. Ask him what power setting (RPM) he recommends on each leg, too.


What's the difference between feathering, and flapping in a helicopter?

Feathering

The collective pitch control, or collective lever, is normally located on the left side of the pilot's seat with an adjustable friction control to prevent inadvertent movement. The collective changes the pitch angle of all the main rotor blades collectively (i.e., all at the same time) and independent of their position.

That's what you referred to as feathering, notice it says "independent of their position". It's for collectively increasing or decreasing of the lift on all blades—the engine will keep the RPM constant.

Using the collective in level flight would cause a climb or descent, while with the helicopter pitched forward an increase in total lift would produce an acceleration together with a given amount of ascent.
— Wikipedia

Flapping
Flapping is position dependent as explained here. Flapping is not pilot controlled. It's to counter the dissymmetry of lift.


Does the avoidance of thrust reverser save fuel?

Without further knowledge of the procedures/state of the (a) airport, (b) airline and (c) aircraft , I don't think any conclusive answer could be made. To throw some thoughts in:

All of Kuala Lumpurs's runways are over 4000 meters long, and braking an A320 (at landing weight) can easily be done without thrust reversers over that distance.
Depending where the gate was, they may simply have wanted use more of the runway to speed up the taxi, in which case excessive braking would have been undesirable. Most standard procedures call for a minimum of idle reverse thrust however.
The thrust reversers may have been inoperable, i.e. broken. You are allowed to fly an A320 in that state.

Update: Since you said you didn't sense any thrust reversers (vibration/sound, i.e. no visual confirmation), here's a video to show that they can be pretty quiet even if the doors are opened. If you follow the spiral painted on the spinner note the speed doesn't appear to change a lot even after the plane leaves the runway and the reverser doors are closed.

(Touchdown at 6:50)


What is "Boost"/"Super Boost" in the PW127M/N?

"Boost" is an informal name for the ATR72 "Automatic Takeoff Power Configuration System" (ATPCS) which allows for higher than normal takeoff weights.

Higher weights are allowed because the system automatically:

1) senses an engine failure

2) feathers the bad engine

3) applies up to 10% increased power to the good engine.

Theoretically a super sharp pilot could do it all just as well, but the ATPCS does it automatically for an increased level of safety.

Other aircraft manufactures may call it "Automatic Performance Reserve" (APR)

ATR 72-600 Brochure


What license woud an ex-military aircraft (E.g, L-39) go under according to the UK-CAA, an EASA licence or a non-EASA license?

According to CAP 632

  6.1 Ex-military aircraft on the UK register with a ‘Permit-to-Fly’ may be piloted by either private or professional licence holders. Pilots must hold a current civil licence with a current civil class or type rating appropriate to the ex military type[s] being flown or where no civil type rating exists, an Aircraft Type Rating Exemption from the need to hold a type rating.
   Any questions relating to licence matters should be addressed to CAA PLD

...

  Any turbine-powered aeroplane - To fly an ex-military turbine-powered
  aeroplane a pilot must hold an Aircraft Type Rating Exemption. See paragraph
  6.7 for details of obtaining an Aircraft Type Rating Exemption

and so on.

Ex-military aircraft are non-EASA aircraft. Ref