Why doesn't a wing in supersonic flow produce a shock that results in flow parallel to the leading edge?

Air needs to make way for the approaching airplane. For that, it takes the route of least resistance, which is above and below the wing. This is shown in your first picture which is valid for a supersonic leading edge. Your top view shows a different cross section through a three-dimensional shock at a much lower speed. The vector M$_2$ is wrong and does not correspond to what is really happening.
If X is in flow direction, Y is sideways and Z is down, picture 1 shows a cut in the X-Z plane for a supersonic leading edge. Picture 3 shows a cut in the X-Y plane for a subsonic leading edge. Here, air does not flow sideways but continues past the shock along the direction of the vector M$_1$.


Re old (1993) US VFR sectional charts-- when did the term "Class E" first appear?

According to this AOPA article, the change was made in Sept, 1993

  In a move to simplify airspace classification, the FAA will rename the different airspace categories on Sept. 16, 1993. In order to fall in line with ICAO (International Civil Aviation Organization) practices, it will replace descriptive titles, such as Terminal Control Area, with alphabetical designators, such as Class B Airspace. This change will be phased in gradually. Charts and references will carry both designations until pilots get used to the transition.

https://www.aopa.org/members/ftmag/article.cfm?article=1054

And some more background

  A Brief History of Aeronautical Charting

  To understand the change that GIS has brought to the National Geospatial-Intelligence Agency (NGA), it is helpful to be familiar with the history of aeronautical charting.

  Shortly after the Wright brothers made their historic first flights, the skies began to fill with aircraft. Visibility was the key navigational tool at that time. Aircraft were limited to short flights in clear weather and used transportation routes to navigate by, flying low to the railroads during reduced visibility. Early pilots began making personal notes to help them navigate to and land at increasingly distant airports, and enterprising pilots sold these notes to other pilots, but air travel remained limited by visibility.

  In the 1930s, radio technology made it possible for pilots to navigate farther distances through unfamiliar surroundings in reduced visibility. In 1941, the first instrument approach and landing charts were developed, serving pilots with the need to land in low visibility.

  By this time, aviation was a matter of interest worldwide. Many organizations began drafting standards for aviation-related maps, charts, and information. During World War II, the demand for charts increased dramatically. By 1943, production had increased from around 500,000 per year to more than 11 million. The U.S. Army and Navy air forces each built their own custom charts to fit their wartime needs.

  By the end of the war, it was clear that standardized products and symbology were needed to support international air travel. The following years saw the establishment and maturity of many of the aeronautical- and aviation-related agencies and associations that we see today, such as the U.S. Federal Aviation Administration and the United Nations International Civil Aviation Organization (ICAO), each mandated to ensure the safe, efficient, and orderly evolution of international civil aviation.

  Today, these organizations and others drive the look and feel of aviation products worldwide. They have also mandated an update cycle to ensure that all aircraft are flying on the same data. Depending on the region of the world, this cycle is effective every 28 days or multiples of 28 days. It is easy to see how a map of the world's airports and airways, updated every 28 days and limited by international standards, can become a huge challenge. This challenge is the mission of NGA's Aeronautical Division.

http://www.esri.com/news/arcnews/summer07articles/a-brief-history.html


Do I need to use an airfield to take off or land a powered paraglider?

NOTE: My answer is US specific
Not only is there no need to operate from an airport, it is recommended not to, if there are aircraft operating from the airport. Paramotors operate (in the US) under FAR Part 103.

103.13 Operation near aircraft; right-of-way rules.
(a) Each person operating an ultralight vehicle shall maintain vigilance so as to see and avoid aircraft and shall yield the right-of-way to all aircraft.
(b) No person may operate an ultralight vehicle in a manner that creates a collision hazard with respect to any aircraft.
(c) Powered ultralights shall yield the right-of-way to unpowered ultralights.

In addition to the above,

103.15 Operations over congested areas.
No person may operate an ultralight vehicle over any congested area of a city, town, or settlement, or over any open air assembly of persons.

as well as

103.17 Operations in certain airspace.
No person may operate an ultralight vehicle within Class A, Class B, Class C, or Class D airspace or within the lateral boundaries of the surface area of Class E airspace designated for an airport unless that person has prior authorization from the ATC facility having jurisdiction over that airspace.

It is common to operate a paramotor from (launch from and land on) a park or other cleared field, as long as you don't launch over a large number of people. In my area of Virginia, there are some paramotor pilots who use a public park and launch themselves along an edge, so as not to fly over on-going soccer games.


What keeps certified GA aircraft from being affordable?

Low volume, high liability, and the overhead of certification all contribute to the high price of factory-new aircraft.

Certification

The process to design, build, and test an aircraft to receive a type certificate from the FAA adds time and cost to any new clean-sheet design (substantially more cost if the design is novel in some way).
The design and construction techniques must conform to the requirements in the FARs, and you have to demonstrate conformance to FAA inspectors (who will also want to see you assemble a few planes under their oversight before issuing you a production certificate to go ahead and make them on your own).

Volume

50+ year old designs like the Piper PA-28 and Cessna 172 that are still in production on an approved type certificate avoid that cost, but are still a low-volume high-touch product: Here's a wing being assembled.
Because of the relatively low demand (and thus low sales volume) the cost of the skilled personnel to build aircraft isn't spread out the way it is with cars (and the investment in large-scale low-touch automation isn't economically feasible). That drives up the manufacturing cost, and the price goes up with it to ensure the manufacturer is still making a profit.

Similar economies of scale affect all the third-party parts going into new planes as well: radios, instruments, lights, etc. that conform to applicable FAA Technical Standard Orders (TSOs) are rather expensive.

Liability

Finally, any new aircraft starts a new 18-year liability period for the manufacturer. Any accident that results in whole or in part from manufacturer errors, omissions, or negligence in a new aircraft can come back to haunt that manufacturer in the form of a lawsuit, so the cost of product liability insurance is baked into the price of every new aircraft. (After 18 years the manufacturer is off the hook thanks to the General Aviation Revitalization Act.)

All of these factors take the Searey from being a \$50,000 kit (airframe, engine, and propeller) to a \$150,000 factory-built Light Sport aircraft, and that is putting it on the market as a Light Sport aircraft under "consensus industry standards". Producing it as a Part 23 certificated aircraft would add the additional cost and requirements of FAA certification.
(I'm using the Searey as a convenient example since you mentioned it in your question and I could find kit and factory-built pricing easily, but other light sport aircraft available in both kit and factory models seem to stack up similarly. I don't know of any that have been subsequently "upgraded" to a Part 23 aircraft: Only a few manufacturers have successfully launched that sort of product, and those command rather substantial prices on the new market.)


Why is luggage required to be loaded in containers?

The central cargo hold is usually pretty big and open, if cargo was placed in loosely then it might shift in flight which can cause the center of mass to shift or damage the walls of the hold. Putting them in containers and fixing those down will prevent that.

The containers can also be weighed before hand and their position set to ensure the center of mass ends up where it should be. With loose cargo the pilot would need to rely on the intuition and experience of the loaders to ensure that they don't put all the heavy stuff on one side.

Loading loose luggage requires that the loader in the cargo hold handles each bag while stacking them. The hold also needs to be full enough that the luggage can't shift around.

The smaller forward and rear cargo holds (or on smaller planes) can still accommodate loose luggage (or more precisely they are too small for the containers to fit). They will also have netting to provide barriers against shifting.


If we're talking about large aircraft the answer is Powerful enough that you want to stay out of them.

I refer you to this delightful FAA video in which a Cessna (looks like a 172) was flown into the wake of a C-5 Galaxy. The Cessna was rolled through 360 degrees by the vortex.

NASA research has shown that the rotational speed of wake vortices can exceed 150 miles per hour (130 knots).
While the Enhanced Fujita Scale rates tornadoes based on damage a 150 mile per hour wind speed is in the range estimated for an EF3 tornado ("Severe Damage", defined as Entire stories of well-constructed houses destroyed; severe damage to large buildings such as shopping malls; trains overturned; trees debarked; heavy cars lifted off the ground and thrown; structures with weak foundations are badly damaged.) - This should reduce your desire to be anywhere near the wake vortex of a large aircraft.

If we're talking about smaller aircraft (say two Cessnas flying in trail, and the trailing aircraft somehow gets below the lead) it's strong enough to be unpleasant - the wake from the leading aircraft will shake and rock the wings of the trailing aircraft, but it probably won't flip the trailing aircraft over.

Many pilots are familiar with encountering their own wake at some point in flight training: It can happen when practicing steep turns in calm air.
If the weather and timing of the turn are "just right" and you produced a circle rather than an oval yo will hit the descending wake from your outside wing as you roll level at the 360 degree mark. This produces a slight "bump" at the end of the maneuver (visible in this video).


Reasons for significantly lower than normal approach

The winds were coming from dead East 090°: See METAR, at >15kts. This strongly favours a landing on runway 10. The predominant winds in Blackpool are from the West, which may be why this is unusual to you.

The approach you mention is just one of the possibilities. The charts also give the option to approach directly from the West. Outside of the published approaches, one could imagine that ATC vectored the Cessna in on a quicker path to beat the incoming helicopter.


Is the Airbus A380 a viable shorthaul airliner?

I can't say if anyone has looked at a short-haul version of the A380, but we can look to the Boeing 747-400D for comparison.

In addition to removing the wingtip extensions and winglets as described in the Wikipedia article, a friend at Boeing described to me other changes needed. Boeing beefed up the wing box due to the increased landing cycles. There were also some changes to the brakes to improve cooling as the short flights didn't provide adequate time to cool the brakes passively.

It should be noted that ANA was the only customer with 19 aircraft built. They retired the last of them 3 years ago. So it would appear that there isn't much of a market for a short haul jumbo.


Does the expression "stall speed" have a definition?

Indeed, "the stall speed of an airfoil doesn't exist." But the stall speed of an airplane does exist, though it's dependent on the aircraft weight $W$, load factor $n_z$, configuration (e.g., flaps position) and the air density. This variability makes it disadvantageous (for pilots---even dangerous) to think of an airplane's stall in terms of a definite stall speed $v_{Stall}$, as if it were a constant characteristic of the type. What are (roughly) constant are the stall angle of attack and the stall lift coefficient $c_{L_{Stall}}$.

The equilibrium equation for the forces acting on the airplane In stall in its symmetry plane and perpendicular to its velocity is:

$$n_z\cdot W = \frac{1}{2}\cdot\rho\cdot v^2_{Stall}\cdot S_{ref}\cdot c_{L_{Stall}}$$

Doing the algebra, one can easily exspress the stall speed in terms of the remaining parameters ($\rho$ = density of air, $S_{ref}$ = reference area) The resulting expression will explain (i) that for an airplane, stall speed does exist; (ii) the nature of its dependences and (iii) that for an airfoil, to which force equilibrium does not apply, there is no "stall speed."


Jet streams are influenced by the horizontal temperature gradient between two air masses which creates what is called a "thermal wind component", which when supplemented by the actual wind movement, creates the local acceleration of wind running along the top of the frontal boundary into a jet (above 90kt), and which is always nestled into the warm air side, in the wedge of warm air just under the warm air tropopause.

The strength of the jet is therefore influenced by the temperature difference between air masses.  In winter the airmass boundaries (in North America) tend to move south, and the temperature differentials increase compared to summer.  With the higher temperature differentials and higher horizontal temperature gradients, the stream velocities tend to be stronger and they reside farther south.

If you really want to understand aviation weather theory, the absolute best book for this is the Royal Canadian Air Force Weather Manual. Can't recommend it highly enough.


Why do some countries separate a transition level and a transition altitude?

By definition, the transition level is the lowest usable flight level above the transition altitude. So if there is a transition altitude, there is a transition level.

In the USA, the transition altitude is 18 000ft. If the QNH (altimeter setting) is higher than 1013.25 mbar then the transition level is FL180. This provides at least 1000 ft separation from aircraft flying at 17 000 ft (or 500 ft from the VFR at 17 500 ft).

If the QNH is lower than 1013.25 mbar then the transition level is FL190 or even FL200 to ensure there is at least 1000 ft separation from 17 000 ft.

The transition level in other countries is based on similar logic.


Is it right to extend flaps only in the white arc?

Yes you must slow down to the white arc, or whatever your flap extension speed is for a given condition, regardless.  If you are 10kts above the white arc and drop flaps anyway, it's not going to make the airplane come apart, and if you did it once, slap yourself on the wrist and don't do it again.  It's putting stress on the flap attachments beyond what they are certified for, and eventually if it's done repetitively over a long period you might start seeing cracks in hinge arms, brackets etc.

On transport airplanes if you do that you get an overspeed warning and you are expected to declare the incident which will trigger a fairly straightforward visual inspection of the flaps.   On a small a/c, if nothing is bent, don't worry about it if it was just a few knots over, but don't keep doing it.  If it was WAY over, like 20 or 30 kt above the white arc, you should tell whomever owns or maintains the airplane about it so someone who knows what to look for can look it over.

In fact, as a matter of good airmanship, you should get into the habit of being well below the top of the white arc, within reason, before extending flaps (I slow down to not much above the flaps up approach speed before dropping flaps - it's a matter of being on top of how your aircraft flies, and staying ahead of it, mentally).  This is simply a matter of taking care of the machinery and not beating the crap out of it; it'll mean the difference between having to replace hinge bushings at 5000 hrs for the pilot who takes care of the equipment vs 2000 hrs for the pilot who treats his/her plane like a mule.


Why are some fuel-injected engines started with the mixture at idle cut-off?

Often times fuel injected engines can be difficult to start with the mixture rich, particularly if run recently and still hot.  Following a priming procedure with the electric boost pump then cranking with the mixture at idle cutoff allows the engine to flush out fuel from the injector manifold until an optimal fuel air mixture is reached and the engine starts up.  Quickly moving the mixture to full rich at this point will stabilize the engine at idle with an appropriate throttle setting.


Did the DC-9 ever use RATO in revenue service?

The JATO/RATO retrofits were used only by Overseas National (later National Airways) when operating out of hot/high airfields for military contracts. They were never used as passenger flights, but you could say that these were "revenue" flights as they were done for monetary compensation.

I can't find any history on ALM980, only that it was registered as N935F and operated by Overseas National as a passenger flight. N935F does not show any history in the FAA registry other than it being reserved. It is possible that this was a converted cargo aircraft.

Here is a picture of an Overseas National flight using the JATO rockets:

Source: UT Dallas

It should be noted that the DC9 was not the only passenger type aircraft to get the "JATO" treatment. Boeing modified the 727 to operate out of short fields by adding JATO rockets. Aviation Week did an article featuring the DC-9 JATO modifications:

Source: Aviation Week (article paywall)

The magazine cover linked above shows a DC-9 take-off (an Overseas National flight).


Why are autorotations to a full touchdown not practised any more?

Too many broken off tail booms.  The Army can afford to replace damaged machines; flight schools that can barely afford hull insurance on recip helicopters in the first place, if at all, not so much.  (Funny story: I once asked an aviation insurance broker why the hull premiums on recips were so high, like over 5% of hull value back in the 80s (before Robinson's program).  He said, "Cuz they all crash!!!!" and laughed.  He said mainly it was because they are used for the most high risk activities: ab-initio training and Ag.)

Anyway, the FAA decided some years ago to remove the full auto from all but the instructor rating because, in a nut shell, it was calculated that the number of chopped off tail booms from training accidents attributable to full autos is way more than the number of chopped off tail booms from real full autos, where the hard landing could be blamed on removing the training requirement. Effectively, choosing one risk profile over another because the statistics favored it.

Not too different from ending the old practice of live engine cuts during multi engine training.  Except for a simulator, a multi pilot never experiences a real engine cut on takeoff until it really happens.  Back when live cuts were done, there were way more failure-to-maintain-control crashes in training than crashes from real engine failures.


How do dummy bombs simulate real bombs in training when they're so much smaller?

The actual mass alone is nearly irrelevant to its a trajectory - what mostly matters is the mass/drag ratio - so if you scale the drag correctly, it feels quite the same - at least from the operational point of view. As one does not drop bombs by sight only, a small adjustment on the computer will do the other trick.


There is always a backup radio system as well as a several backup systems like for example a backup CWP (controller worker position) in case the primary fails. PANS-ATM (ICAO doc 4444) in chapter 2.5 SAFETY REVIEWS mentions that

  Operational and technical issues to ensure that: [...] communications, navigation, surveillance and other safety significant systems and equipment [...] include adequate backup facilities and/or procedures in the event of a system failure or degradation.

Emphasis is mine.

Also there is a standby generator (or even more than one) that has to instantly take over in case of power supply failure but I can't find any regulations at the moment.

As for the "what happens if the backup fails as well" question, we need to see the fuller picture that the document provides:

  d) communications, navigation, surveillance and other safety significant systems and equipment:

  1) are tested for normal operations on a routine basis;

  2) meet the required level of reliability and availability as defined by the appropriate authority;

  3) provide for the timely and appropriate detection and warning of system failures and degradations;

  4) include documentation on the consequences of system, subsystem and equipment failures and degradations;

  5) include measures to control the probability of failures and degradations; and

  6) include adequate backup facilities and/or procedures in the event of a system failure or degradation;

Emphasis is again mine

As you can see backup is the last line of defense. An ATS unit should ensure that equipment is regularly maintained, it's monitored, it's tested and any failures should be prevented if possible and their impact being documented.

If everything else fails, then you use the backup. And again the "include adequate backup" phrase can be translated as "if one thinks that a second backup is needed they should install one". But the previous 5 clauses are there to eliminate that case.


Do Freon gas leaks occur in Airplane conditioning systems as well?

Large aircraft use air conditioning packs (air-cycle machines) which uses only air, compressors and heat exchangers to cool/heat the air. There is no freon involved.


How important is it to have talent to become airline pilot?

You are asking the wrong question. Ask yourself this:

Do I really want to become a pilot?

If the answer is yes, then you can become a pilot. You only require hard work, and a lot of money (but we are not talking about this).

Having talent is subjective. Sometimes you try to learn something new and you get into that relatively quickly. Sometimes you don't. It doesn't just depend on talent, but on several factors.

If you feel that you are not making any different mistakes than other student pilots, then change your instructor.

There are several discussions about changing flight instructors. You can benefit from these ones:

What to look for in a flight instructor?
Is there a downside to trying multiple flight instructors?


Why generation of lift is more at mid span of the wing?

The diagram might be a bit more clear if a fuselage were attached to one of the sides.
If that were the case, lift would be less on one side because of the fuselage is interfering with the air flow.  Lift would be less at the other end due to washout (lowering of wing tip angle of incidence), and effects of higher pressure spilling from the bottom around the wing tip towards the lower pressure on the upper wing (vortex formation).
The airstream in the middle of the wing experiences neither of these two interferences, generating lift most efficiently.
This is why gliders favor very long (high aspect) wings, where most of the lift is like the "middle" of the diagram.


How many airport charts do airline pilots have in the cockpit?

In the 1990s I flew for two 747 carriers, the first primarily a freight carrier and the second primarily a passenger carrier. Both used Jeppesen for their airway manuals, and both supplied each pilot with a single, full-size and very full Jepp manual that contained as many as possible of the airports we might go into. Image below:

As I remember, the criteria for whether a plate would be in our personal binder included the airport having a runway at least 5000 feet long.

Both carriers did extensive charter work to every continent save Antarctica, and we would occasionally be dispatched to an airport that our personal Jepp manual didn't have. The freight carrier handled this problem by having aboard each aircraft a flight bag with full, world-wide coverage, 5 or 6 manuals as I remember. In theory the manuals were kept current by updating them each time the aircraft went through its base, but in practice they were almost always out of date, but at least they were there in case of an inflight diversion to an unplanned airport.

The pax carrier handled the problem of an airport not in our personal coverage by faxing the plates with our flight plans. In case of an unplanned inflight diversion, dispatch would read the pertinent information to us over HF, a very tedious procedure, obviously. I only had that happen once.

It was a different world back then with no ubiquitous Internet. I typically spent 300 to 400 dollars per month in international phone calls to my wife. No Skype, no WhatsApp, Compuserve for email until around 1996 or so, then sporadic Internet, but always dial-up and with ridiculous charges by the hotels.


Do aircraft obtain better milage by flying high or by using "ground effect?"

There really isn’t any strict single rule on whether an aircraft should fly high or use ground effect to increase endurance. It all depends on the design requirements and the purpose of the aircraft.
For cargo type aircrafts, it would make sense to use ground effect and fly over the sea, since speed is not really a major concern.
For reconnaissance aircraft, using ground effect is obviously impossible. For that they have to fly high and the optimum altitude would depend on aircraft parameters, and be a strong function of weight and possible induced drag.


How can a two-engine B787 create three contrails?

Contrails are created due to variances in the pressure of the air, coupled with the amount of moisture in that air.  When the 2 engines of the B787 blast their exhaust out, the high pressure of the exhaust temporarily causes the moisture to condense.  Two contrails are visible.

However, as the pressure waves from the 2 exhaust trails propagate through the open atmosphere, they interfere with each other.  This interference can also affect the pressure of the moist air between the 2 "primary" contrails, sometimes resulting in another, "secondary" contrail.  In fact, because of this, if there were enough moisture in the air, and the engines were powerful enough, there wouldn't actually be just 3 contrails.  Rather, the contrails would present themselves as the crests of a propagating wave much like the crests of water waves as a duck swims by.  In effect, we would see the 3 contrails separating, and between each of the 3 contrails, 2 more "tertiary" contrails would be visible.

Here on Earth though, the pressure variances and the density/moisture content of the air normalize far before any of that exotic pressure wave stuff could occur.  Except we DO get that one in the middle!


What are the laws on photographing aircraft in Australia?

There is no law in Australia prohibiting the photography of aircraft. I have been approached by police while doing it just to see what I was up to, but after a polite exchange they were happy and moved on.
Potentially, if you're on private property (eg an airport terminal), the conditions of entry are allowed to prohibit the taking of any photos. But I'd be shocked if that is applied anywhere outside of theatres or defence bases. You try telling travellers they're not allowed to take an airport selfie for instagram.
If you're using the photos for commercial reasons, and they include a trademark (like an airline logo), you might need to contact them for permission, I'm not certain how that process works. But this certainly doesn't apply for private use.
Having said all that, I am not a lawyer, so if you're worried or want specific information you should at least ask on a legal forum, if not pay for a professional opinion.


Would a 737 pilot use flaps in nose dive?

No, flaps are never used during a nose dive.

We need to distinguish between two scenarios:

Intentional nose dive: this is actually called a rapid descent maneuver. The FCTM (Flight Crew Training Manual) has a whole section dedicated to it. The general procedure looks like this:

From the Boeing 737 NG FCTM (7.5 Maneuvers - Rapid Descent - Level Change (LVL CHG)):

  Because of airspeed and altitude protection and reduced crew workload, use of the
  autopilot with LVL CHG mode is the recommended technique for rapid descents.
  Use of the V/S mode is not recommended.

  Initiate a turn, if required, using HDG SEL. Set a lower altitude in the altitude
  window. Select LVL CHG, close the thrust levers and smoothly extend the
  speedbrakes. Autothrottles should be left engaged. The airplane pitches down
  smoothly while the thrust levers retard to idle. Adjust the speed as needed and
  ensure the altitude window is correctly set for the level off. During descent, the
  IAS/MACH speed window changes from MACH to IAS at approximately 300
  KIAS. Manually reset to VMO as needed.

  When approaching the target altitude, ensure the altitude is set in the MCP altitude
  select window. Altitude capture engages automatically. Adjusting the command
  speed to approximately LRC or 300 knots before level-off aids in smoothly
  transitioning to level flight. The pitch mode then controls altitude and the thrust
  levers increase to hold speed. Smoothly return the speedbrake lever to the down
  detent during the level off maneuver.

  When descending with the autopilot engaged and the speedbrakes extended at
  speeds near VMO/MMO, the airspeed may momentarily increase to above
  VMO/MMO if the speedbrakes are retracted quickly. To avoid this condition,
  smoothly and slowly retract the speedbrakes to allow the autopilot sufficient time
  to adjust the pitch attitude to maintain the airspeed within limits.

  When the speedbrakes are retracted during altitude capture near VMO/MMO, a
  momentary overspeed condition may also occur. This is because the autopilot
  captures the selected altitude smoothly by maintaining a fixed path while the
  thrust is at or near idle. To avoid this condition, it may be necessary to reduce the
  selected speed and/or descent rate before altitude capture or reduce the selected
  speed and delay speedbrake retraction until after level off is complete.

In case a higher descent rate or lower descent airspeed is required, the landing gear can be extended additionally to the speedbrake, but flaps are never mentioned:

  Landing Gear Extended Descent

  The rapid descent is normally made with the landing gear up. However, when
  structural integrity is in doubt and airspeed must be limited, extension of the
  landing gear may provide a more satisfactory rate of descent.

  If the landing gear is to be used during the descent, comply with the landing gear
  placard speeds.

Accidental nose dive: this would fall under the general term of upset. The recommended procedure is described in the FCTM (7.26 Maneuvers - Upset Recovery):

  Nose Low, Wings Level

  In a situation where the airplane pitch attitude is unintentionally more than 10°
  nose low and going lower, the airspeed is increasing rapidly. A pilot would likely
  reduce thrust and extend the speedbrakes. Thrust reduction causes an additional
  nose-down pitching moment. Speedbrake extension causes a nose-up pitching
  moment, an increase in drag, and a decrease in lift for the same angle of attack. At
  airspeeds well above VMO/MMO, the ability to command a nose-up pitch rate
  with elevator may be reduced because of the extreme aerodynamic loads on the
  elevator.

  Again, it is necessary to maneuver the airplane's flight path back toward the
  horizon. At moderate pitch attitudes, applying nose-up elevator, reducing thrust,
  and extending speedbrakes, if necessary, changes the pitch attitude to a desired
  range. At extremely low pitch attitudes and high airspeeds (well above
  VMO/MMO), nose-up elevator and nose-up trim may be required to establish a
  nose-up pitch rate.

Also here, flaps are not mentioned, so only speedbrakes should be used to increase drag (and increase the nose-up pitching moment).


Can you log both XC PIC time and simulated instrument time together?

You can log XC, PIC, simulated instrument, category/class, day/night, Total flight time.

From a regulation standpoint.
Cross time can be logged pursuant to §61.1

  Cross-country time means -

  Except as provided in paragraphs (ii) through (vi) of this definition, time acquired during flight -

    (A) Conducted by a person who holds a pilot certificate;

    (B) Conducted in an aircraft;

    (C) That includes a landing at a point other than the point of departure; and

    (D) That involves the use of dead reckoning, pilotage, electronic navigation aids, radio aids, or other navigation systems to navigate to the landing point.

  For the purpose of meeting the aeronautical experience requirements (except for a rotorcraft category rating), for a private pilot certificate (except for a powered parachute category rating), a commercial pilot certificate, or an instrument rating, or for the purpose of exercising recreational pilot privileges (except in a rotorcraft) under § 61.101 (c), time acquired during a flight -

    (A) Conducted in an appropriate aircraft;

    (B) That includes a point of landing that was at least a straight-line distance of more than 50 nautical miles from the original point of departure; and

    (C) That involves the use of dead reckoning, pilotage, electronic navigation aids, radio aids, or other navigation systems to navigate to the landing point.

PIC time can be logged pursuant to §61.51(e)

  (e) Logging pilot-in-command flight time.

    (1) A sport, recreational, private, commercial, or airline transport pilot may log pilot in command flight time for flights-

      (i) Except when logging flight time under § 61.159(c), when the pilot is the sole manipulator of the controls of an aircraft for which the pilot is rated, or has sport pilot privileges for that category and class of aircraft, if the aircraft class rating is appropriate;

All others are logged as a requirement under §61.51(b)


What is the weight of the batteries on the e-Fan?

The weight of the battery is mentioned here:

  Power is provided by 127 kg. of 250-volt lithium-ion polymer batteries
  from Kokam in South Korea built into the wing.

A slightly different weight is specified here:

  ... E-Fan has two lithium-polymer battery packs weighing 65 kg each.

I could not find which Kokam battery is being used on the e-fan, but this page has specifications for all of their batteries.


Why do most A320s make that distinct scream on takeoff?

The whining noise is generated by the rotating components in the engine. At takeoff power for an engine of that size, the fan is rotating at about 5200 rpm. This is about 86 times per second. There are also 22 blades on the fan at the front of the engine. This means a given point sees a fan blade pass about 1900 times per second. Each fan blade changes the pressure as it passes, resulting in a tone of about 2kHz. This is the whine that you hear. At takeoff the tips of the fan blades are going supersonic, each one creating a shockwave.


What is the difference between planned true airspeed and actual true airspeed?

It's very possible that your flight computer's TAS calculation is expecting calibrated airspeed rather than indicated airspeed; the difference between these two can often be enough to affect your results by a meaningful amount.

Most aircraft do not have a formula for the conversion, or enough information to convert airspeeds other than those specified in the manual. This means that the "CAS" used for TAS calculations is often actually IAS.


How am I supposed to track to KOSAX on the OLIVI 4W out of EDFM?

The textual description for OLIVI 4W is:

OLIVI FOUR WHISKEY
On track 256° to 6.0 DME MND; RT, on track 333° to KOSAX;
LT, on track 294° to OLIVI.
Climb with 7.9% (480 ft/NM) or more until passing 3000,
then climb with 6.4% (390 ft/NM) or more until passing 6000.

However, the remarks section holds the answer:

1. PDG 7.9% (480 ft/NM) due to obstacles.
   If unable to comply, request alternative instruction by ATC.
2. PDG 6.4% (390 ft/NM) due to airspace structure.
3. After 6.0 DME MND BRNAV equipment necessary.
4. During activity of ED-R 205 (TRA) MAX FL80.

Note "3. After 6.0 DME MND BRNAV equipment necessary."

BRNAV in this case means "Basic RNAV", which is essentially a form of RNAV equipment, but with less stringent certification requirements compared to normal IFR RNAV equipment.


How do you calculate coefficient of drag at an angle?

Let's try to derive something. Assume the x-axis points to the right and the y-axis points up. I'm gonna use the subscripts b and s for bottom and side. The incoming velocity vector is decomposed in two components along the axes, so $v_s=v\sin\theta$.

Writing the total drag force as a vector:

$\vec D=\begin{bmatrix}-D_s\\D_b\end{bmatrix}=\begin{bmatrix}-C_{D_s}\frac{1}{2}\rho S v_s^2\\C_{D_b}\frac{1}{2}\rho S v_b^2\end{bmatrix}$

Taking the magnitude of the vector:

$D=C_D\frac{1}{2}\rho S v^2 = \sqrt{{C_{D_s}}^2\left(\frac{1}{2}\rho S\right)^2 v_s^4+ {C_{D_b}}^2\left(\frac{1}{2}\rho S\right)^2 v_b^4}$

This can be further simplified to:
$C_D = \sqrt{{C_{D_s}}^2\sin^4\theta+{C_{D_b}}^2\cos^4\theta}$

I don't think this can be simplified further.

Edit: S in this case is of course just the area of the rectangle, I got confused before


Who operates a 707 with Boeing factory livery?

Official airplane of Democratic Republic of Congo

Today, the Democratic Republic of Congo uses a B707-138B, registered 9Q-CLK: LK for Laurent Kabila.

Laurent Kabila has been Congo's President until his assassination (he was succeeded by his son).

This is an airplane with a long history (and some controversy). She has now 707 painted on the tail, but not the Boeing markings. Thanks to our friends at Airliners.net several pictures are available:

(source: Airliners.net, Mark. Szemberski)

Once this a/c had no logo at all, here in 2008:

(source: Airliners.net, Weimeng)

On Youtube too: B707 9Q-CLK .

Qantas in the past

Back in 1959 when it entered service at Qantas as VH-EBG, the first B707 with a 5th engine in a pod-pak:

(source: Qantas Heritage Collection)

More on the curious engine exhaust and the pod-pak.


What are the performance adjustments for a Beechcraft B1900D on a wet runway?

According to the Transportation Safety Board of Canada when they conducted an investigation into a Beechcraft 1900D overrunning a runway in 1997, they found out that the AFM does not include that information you request, nor was it available to the pilots.

  The snow-covered, slippery condition of the occurrence runway differed from the bare,
  dry surfaces on which the AFM data is based.

and

  There were no performance data available to the pilots to determine the aircraft's
  accelerate-stop distance under snowy and slippery runway conditions.

and

  The James Brake Index (JBI) published in the Canada Flight Supplement contains a table which may be used to
  adjust calculated landing distances to compensate for slippery braking conditions. JBI correction factors for
  compacted snow or snow-covered runways range from 80% to 250% higher than hard dry surfaces. Transport
  Canada did not require the manufacturer to provide data on the effects of soft or wet runways, slippery
  runways, or runways containing loose snow on the aircraft's accelerate-stop distances or take-off distances.

How can the aircraft be approved? They say:

  The manufacturer was, as a condition of the aircraft type approval,
  required to determine and supply certain aircraft performance data including the balanced field lengths at
  various take-off weights, temperatures, and altitudes.

I.e., V1 corrections for non-dry runways were (are) not a requirement for the 1900D.

If the AFM you have is current, then it hasn't changed since. If not, then it may be present in the latest AFM. (But I wouldn't count on it, so verify before placing a purchase order.)

You may also look into the aforementioned James Brake Index.


Has any passenger airliner ever offered forward-facing windows?

We could start with the Tupolev ANT-20 with its rather daring forward-facing passenger gallery. [edit - the prime seat right at the front in the gallery was for the navigator and his equipment.]

source

Like the Tupolev, most examples are inter-war. Here is the moderately successful Latécoère 521 being assembled showing its gallery beneath the cockpit [edit - seems this was only for the navigator, not for passengers] :

source

... and the more esoteric Caproni Ca.60 which would have made for an interesting journey had it entered service -

source

-- EDIT - one special mention for the Junkers G.38 which also had a sizable glazed area in the wings. Unfortunately as far as I can tell (and despite what Wikipedia says) neither the nose nor wings were accessible by the passengers, but rather used by the navigators and engineers, which seems like a missed opportunity. [ed. the wing area was indeed intended for passenger, see comments]

source


How do fighter jets measure how high they are?

Fighter jets have the same system as commercial aircraft: An altimeter based upon external air pressure. this measures their altitude relative to pre-defined atmospheric conditions. Many will also include a secondary system that relies on GPS (or local equivalent) signals to produce a height above the reference geoid rather than an atmospheric datum.

Regarding your second question - you should only post one question per topic. An answer is difficult as the construction varies significantly between manufacturers. Many pitots are made of steel variants, however.


In a 747 is it normal for the Vr (takeoff speed) to vary greatly depending on fuel load and ambient temperature?

As Henning Makholm's answer discusses, the weight difference between the lowest and highest weights is significant. The operating empty weight (OEW) of a 747-400 is 394,100 lb, while the maximum takeoff weight (MTOW) is 875,000 lb. This means there is a difference of about 400,000 lb between the lightest and heaviest weights at which a 747 may be taking off, making the MTOW about twice as heavy as the OEW.

The rotation speed Vr is the point at which the aircraft can pitch up and develop enough lift to climb. So at MTOW, the 747 must develop about twice as much lift than closer to OEW. Most of this force is lift from the wings.

Lift can be calculated with the following equation:

L = 1/2ρv2sCL

L = lift
ρ = air density
v = airspeed
s = wing area
CL = lift coefficient

The air density will certainly play a role. Higher altitudes and temperatures reduce the amount of lift. But this example pertains to the other variables.

An airliner can use flaps and slats to increase the CL and s of its wings.

The CL will also depend on the angle of attack α of the wings. An approximate curve for the 747 can be seen here (it's for a 747-200, but it should be close enough). When an aircraft rotates, it is changing the AOA, which increases the lift. It is very important when designing an aircraft to make sure it can pitch up enough while on the runway to achieve the pitch angle needed for takeoff. A 747-400 rotates to about 10 degrees on takeoff. Based on the approximate CL-α diagram, the lift coefficient changes from about 0.3 to 1.25 when α changes from 0 to 10 on rotation.

When the aircraft weight is increased, flaps may be increased from 10 to 20. However, flaps 20 may be standard because these guys said so, so lets assume that CL and s will also not change. This leaves the airspeed v as the only parameter left to increase lift.

In this study, figure A-7 shows a distribution of ground speed at liftoff that lies between 140 and 190 kts. These numbers will probably be a little higher than Vr due to the acceleration between Vr and liftoff, and an average headwind. This means that at weights at the lowest end, 130 kts would be a reasonable estimate for Vr.

So now lets make up some numbers. Lets take the weights 475,000 lb and 875,000 lb. Assume that the aircraft needs a lift 10% higher than its weight to take off. This gives us lift values of 522,500 lb and 962,500 lb. Using the lift equation and a low end speed of 130 kts to find the unknown portion.

522500 = 1/2ρ1302sCL

ρsCL = 61.8

Since we are assuming none of those vales will change, we can solve for v at the higher lift value.

962500 = 61.8/2v2

v = 176 kts

This is not too much lower than the high end liftoff value of 190 kts. So there you have it. Lift must be increased to account for the additional weight, and lift is proportional to the square of the airspeed.


How were the fuel tanks sealed on the XB-70 Valkyrie?

According to Valkyrie - North American XB-70A by Steve Pace, leakage problems existed.

...engineering changes, weld stresses, and areas where it was not considered important to test-pressurize, combined to create an accumulation of leakage problems.  Brazing repairs to the leaking areas proved ineffective.

To the point that

The rearmost fuselage tank on XB-70A No. 1 became increasingly difficult to seal and therefore was never used.

The mitigation was

A non-metallic material made by DuPont called Viton-B was eventually used to coat the porous areas.

(p. 69)
It goes on to discuss that it still didn't work that well.
Fuel tankage diagram from the book


Do flights of a specific callsign always depart and arrive at the same airports?

You may be confusing callsign (with can be multiple things) and flight code/number as FlightAware may display one or both of these things depending on whats applicable. FlightAware tracks publicly available filed flights at a variety of levels depending on what callsign you search/are looking at the answer may change. For example

American Airlines runs flight AA66 (AAL66) from JFK to BCN and the code AA66 is used to identify that flight (AA67 is the return flight). This code may also be used for a code share. Generally these codes stay fairly consistent unless there is an overlap (see ymb1's) comment for how dupes are handled.

Generally non scheduled commercial and private traffic the flight files with their tail number, for example in the US tail numbers are often 5 (or possibly 4) digits and a preceding N. So N12345 may file for a flight from anywhere to anywhere they want to go. This history log is a good example of a charter plane that seems to fly out of KDYL to lots of places.


Why are general aviation avionics so expensive?

The cost of rigorous FAA certification versus number of units produced would be my subjective opinion.  Count on our little glass horizon not full up Galaxy 7 catching on fire or even just failing when needed.  That's one of several things we pay for, again: opinion without data.


What is this aircraft, and what country makes it?

This is a Raytheon Sentinel R1, which is produced by Raytheon (US) and Bombardier (Canada). The aircraft in your picture is operated by the Royal Air Force.

(Image Source: WikiPedia - Author: Alan Radecki)


What to do if expediting your ascent or descent is impossible/unsafe?

You report unable, and ATC will come up with a different plan.

To provide some context: If I ask you to expedite a vertical manoeuvre, it is probably because you are on crossing tracks with another aircraft, and I want you to pass them either above or below. This could be to meet certain level restrictions, or simply because I want to provide you with continuous climb/descend as a service. At your current rate, you will probably pass them, bot not quite with the 1000 ft vertical separation I need. Because you are so close to fitting into my plan, asking you to expedite is the easiest - it requires the least effort from me, and I won't have to vector you around, giving you a longer than needed flight path.

If you respond with unable, I have other options to choose from, depending on the situation. Typically I would either instruct you to level off or turn. If you are descending through FL160 and I wanted you to go below someone at FL130, I would simply instruct you to level off at FL140, and then descend you further when you are clear, which would only take a few minutes. I could use the phrase "Stop descend FL140, expect further descend in 3 minutes", in which case you could adjust your vertical rate so that you reach FL140 about 3 minutes in the future, resulting in a smooth descend. Alternatively, a turn of 20-30 degrees is often enough to establish lateral separation, which then allows you to descend unrestricted. 3 or 4 minutes later, when you have passed the other traffic, you will be turned back on your track.

The key thing here is communication. As an air traffic controller, when I instruct you to do something, don't think that I don't have backup plans. We are taught to always evaluate situations thoroughly, and come up with 2-3 different solutions to every problem or situation we face. I will start by presenting the easiest solution to you, but if that doesn't work for you, please don't be afraid of informing me - I will then simply choose another solution, and adjust my plan accordingly. And remember, air traffic control is a service. We are here to make your life easier - not the other way around. You can help us doing so by communicating clearly and in due time.


Thanks for the suggestions in the comments.

Using the term “heat exchanger” I was able to find an Aircraft Modelling forum that gave the answer I was looking for.

Interpreting wartime photography: Catalina in Ceylon

It is indeed a heat exchanger system for leading edge anti-icing. The tail appears to have a separate anti-ice system that burns fuel for heat. This thermal anti-icing was introduced on late model PBY-5A. It probably was an optional system.


What are the three sources that are relayed to the brakes and steering control unit of an A320?

I don't know where your text is from, but the 3 sources are:

  The BSCU receives orders from:

  ‐ The Captain's and the First Officer’s steering hand wheels (orders added algebraically),
  ‐ The rudder pedals,
  ‐ The autopilot.

  The BSCU transforms these orders into nose wheel steering angle.

(A320 FCOM DSC-32-20-10)


How much does it cost to ground a B737 max aircraft for an airline?

Well we can look at another grounding case to see what it costs.

Boeing grounded the 787 Dreamliner. This grounding lasted about 90 days (at least as of the estimated costs by ANA, I think the actual grounding lasted about 116 days).

Japanese carrier ANA had the largest 787 fleet at the time with 17 of the 51 in operation estimated it's costs at $15 million.

Doing some simple math, \$15,000,000 for 17 aircraft works out to be about \$882,352 per aircraft for the 90 day grounding. This is about $9,800 per day/aircraft.

They also estimated that this resulted in ¥1.4 billion in lost revenue. This is \$12.7m USD (in today's dollars). That gives a lost revenue of about $3320 per seat, per day (averaging 250 seats per aircraft).

Now taking into account that there are 393 737 MAX aircraft as of the grounding, with an average seating of around 190 passengers, this could cost airlines significantly. Just in terms of costs, extrapolating the 787 numbers and assuming they are grounded for 6 months, looking at about half a billion dollars (*assuming the costs for grounding the 737 are 75% of the 787 in terms of storage and maintenance) for the entire industry.

In terms of lost passenger revenue, we can assume the numbers are about on par with the 787 since it is a more heavily utilized aircraft (shorter routes, more flights/day). Using the same 787 numbers we would be looking at about $44.6 billion dollars, again, industry wide (and yes, this number seems extremely high to me, but working from what ANA claims).

Can they claim this cost for Boeing? Maybe. They may be able to recover the costs of storing and maintaining the aircraft during the grounding. It is unlikely that they would be able to recover the lost revenue (and it would put Boeing out of business to do so). We'll have to see when this all washes out what the airlines do with Boeing. Most likely they will negotiate deals with Boeing for preferential pricing on future aircraft or some other kind of cost-offsetting deal.


Why doesn't ATC use a unified frequency for the same control area?

This situation is due to usually 2+ sectors being worked. Each sector will use its own frequency when split. When these sectors get combined, one of 2 things will happen. 1) The controller will just work with both sectors frequencies keyed up and be listening on both and transmitting on both and have everyone go to the approrpriate frequency for the sector they're in or near. 2) The controller wants everyone on one frequency and has everyone going into those sector's that they are working to be on just one frequency. Frequency congestion and capability(if the transmitters/receivers are different locations for the different frequencies) are also factors.


Why would an airplane pilot choose to intentionally use more runway than required for a takeoff?

Imagine you're doing a takeoff at a high density altitude. You need more runway to get up to speed because your engine is producing less power and you need to move faster to move the same amount of air over your wings as you would at a lower DA.

Aircraft can pretend the DA is higher by using a higher than normal temperature when calculating takeoff information. In jets with automated engine controllers, this setting -in a round about way- allows you to set the engines to produce only the minimum thrust required to get off the ground safely. Since that results in less thrust, there is less wear on the engine and that adds up significantly over time.

Your trade-off for this decreased wear is that you need more runway, which is usually readily available. If you suddenly need full power you just move the throttle to the Take-Off/Go-Around (TOGA) or emergency power setting (or push a TOGA button on the throttle), which overrides the temperature preset.


The stall speed is around 95-100 knots for the older F variant, and something like 90-95 knots for the newer J variants.

A KC-130 can refuel between around 100 and 270 knots. The lower end of this is well within the maximum speed of many military helicopters, eg the Pave Hawk, Black Hawk, Chinoook or Sea Stallion.

That leaves an "overlap" of around 20-40 knots, without having to approach too close to either the stall speed of the KC-130 (around 90-95 knots) or the VNE of the helicopter (usually between 140 and 170 knots for a military helicopter). This is enough for aerial refuelling, which usually states a fairly tight bracket for the refuelling speed.

As mentioned here:

  The United States Marine Corps has chosen the KC-130J tanker to replace its aging KC-130F tanker fleet. The new KC-130J offers increased utility and much needed improvement in mission performance. As a force multiplier, the J tanker is capable of refueling both fixed wing and rotary wing aircraft as well as conducting rapid ground refueling. The refueling speed envelope has been widened from 100 to 270 knots indicated airspeed, offering more capability and flexibility.


Should I hold my breath in case of a decompression?

No. Holding your breath might cause breaking blood vessels in your lung (barotrauma). It is important to equalize the pressure inside your lung with the exterior. That is in fact the most fundamental rule for all scuba divers.

Also see this related question: Is it possible to suffer barotrauma during decompression?


What does a helicopter "gas prod" gauge measure?

The instrument shows the gas generator rpm in the engine. It think you are referring to this scene (screenshot from youtube):

The Bell 412 in the movie uses a pair of Pratt & Whitney Canada PT6T-3BE Twin-Pac turboshafts, which are free turbine engines. The turboshafts used in helicopters consist of,

Compressor

Combustion chamber

turbine
and other components.

The gas producer (from which 'GAS PROD' came) forms part of the turbine. The gas generator forms the first stage that runs the compressor and makes the engine self sustaining. It also runs the oil and fuel pumps. As it is a free turbine, the gas generator stage is not mechanically connected to the next (power turbine) stage. From faasafety.gov:

The turbine section consists of a series of turbine wheels that are used to drive the compressor section and the rotor system. The first stage, which is usually referred to as the gas producer or N1 may consist of one or more turbine wheels. This stage drives the components necessary to complete the turbine cycle making the engine self-sustaining. Common components driven by the N1 stage are the compressor, oil pump, and fuel pump. The second stage, which may also consist of one or more wheels, is dedicated to driving the main rotor system and accessories from the engine gearbox. This is referred to as the power turbine (N2 or Nr).

In some cases, NG is used in place of N1. The gas generator speed is measured in the PT6 engines using a tachometer-generator mounted  on the engine.
From United turbine training Manual:

The tachometer-generator produces an electric current which is used in conjunction with a tachometer to indicate gas generator RPM. The tachometer-generator drive and mount pad are located at the 5 o’clock position on the accessory gearbox and is driven form the internal scavenge pump.


Why is there no Maltese Cross in this non-precision approach chart which has a FAF?

It could be a charting issue.  It is also the same for the NDB Z Rwy 23 approach into LTAY.    Feel free to ask Jeppesen and they will tell you if the chart is in error.

https://support.jeppesen.com/


What ILS type approach my flights landing could be?

The 3 METARs all indicate extremely poor visibility. The first one (02:30Z) said:

0000 R27/0075 FG VV///

which means visibility less than 50m (0000), Rwy 27 RVR 75m (R27/0075), fog (FG) and vertical visibility not measured (VV///).
The second METAR (03:00Z) still reports visibility less than 50m, but RVR has improved to 100m. The Airbus A321 is certified for CatIIIB down to RVR of 75m (Airbus getting to grips with CAT II / CAT III operations), so technically an approach would have been allowed before, but note that the METAR is only updated every 30 minutes. The pilots were probably informed by the tower or approach controller about the actual current RVR value.
After landing, the third METAR (03:30Z) already shows improved visibility of 100m and an RVR of 750m, indicating that the fog has started to clear.

Here are the minima for the Cat II/III ILS Rwy 27 approach at VILK (Lucknow):

The Cat II is out of the question with a required RVR of 300m (or 350m without autoland in Cat D aircraft). The Cat IIIA would have required at least 175m RVR.
Since the RVR was reported as 100m before landing, the pilots must have prepared for a Cat IIIB ILS approach with autoland. Once the pilots verified that the requirements for a Cat IIIB approach are fulfilled, it does not really matter if the RVR gets a bit better by the time they land, so even if it was 200m at the time of landing, the approach would have been performed with Cat IIIB.

Landings with Cat IIIB seem to be quite common in India according to bangaloreaviation.com:

On the domestic side, only the A320 operators Air India (NACIL-I), GoAir, IndiGo, and Kingfisher have most of their pilots Cat-IIIB certified. Boeing 737 operators Jet Airways, JetLite, and SpiceJet have their pilots certified to the lower Cat-IIIA standard (175 metres runway visibility).
[...] not surprising since the Airbus A320/A319/A321 comes with Cat-IIIB capability built-in, [...]


Why is more oxygen required at higher altitudes?

This question is best answered on https://biology.stackexchange.com, but in short it is the partial pressure that counts. This is (pressure in atmospheres) * (percentage).
At 0.5 atm (18 kfeet) you need twice the amount of oxygen in the air (aka 40%) for it to have the same effect on you. Above 38.5 kfeet the pressure is 0.2 atm, so even 100% oxygen will only provide 20% partial pressure of oxygen, which is the same as normal air at sea level


What is the longest time after which plane crash survivors were rescued?

I have not found a period longer than the two you provided (quoted for completeness). It is unlikely that there is a longer period unreported, as that would be a major news item or historical note; it is possible but unverifiable there has been a person survive after a crash longer but was never rescued due to the aircraft never being recovered.

Aviator Bob Gauchie retains the record for solo arctic survival by a downed airman, enduring 58 days of arctic weather before his rescue in Canada 1967.

After 72 days on the glacier, 16 of the 45 people on board the crashed Uruguayan Air Force Flight 571 were rescued alive.

A couple notable contenders and interesting anecdotes:

Howard Snyder was shot down over Belgium during WWII and joined the Belgium resistance, staying with them for over 6 months until he was rescued by US Troops

Louis Zamperini's 47 days on the ocean after his B-24 crashed in the Pacific during WWII, likely an oceanic survival record after a plane crash, was depicted in the film and book Unbroken. Zamperini then spent another 28 months in Japanese prison camps before being repatriated

Roger Locher holds the USAF evasion record behind enemy lines, spending 23 days evading North Vietnamese troops during the Vietnam war after his F-4 was shot down

Juliane Koepecke's 11 days in the Peruvian jungle after falling from a disintegrating airplane

The record for desert survival, albeit with an unfortunate lack of rescue, the crew of Lady Be Good (WWII)

They survived for over a week in the desert with essentially no water, covering 115 miles...The remains of Moore are still lost in the Sahara’s Sand Sea of Calanscio. But he clearly broke all records for stamina and desert survival


Can balloons be stacked in a climable daisy chain to the edge of space?

As you go higher the pressure decreases which means that the density of both the air and the lifting gas goes down.

That means that the higher you want to go the bigger the balloon you need for a given lifting force. Eventually you reach a point where it is not not practical to make the structure light enough to go any higher. The highest altitude reached by a balloon is considerably lower than the lowest altitude at which orbit is practical.

It also means that as you go higher the wind-area of your balloon increases which will put more force on the tether. The loading from the tether, both from it's weight and from winds at various altitudes will further reduce the practical maximum altitude compared to a free floating balloon.

There is also the issue that in low orbit you need a considerable sideways movement relative to the ground. Most of the delta-v in a launch rocket is spent on gaining the sideways velocity, not in gaining the altitude.


What is the plane on the Home Bush Bay Funsaver EP cover?

I submit the Let L-200 Morava.

https://en.wikipedia.org/wiki/Let_L-200_Morava

Engine Nacelles:

Nacelles and Nose Gear:

Nose gear Higher resolution:


Are we expected to fly distanced leg (instead of timed leg) in holding pattern in GPS approaches?

Short Answer:
Yes, the pilot is expected to fly the hold as depicted, with an outbound leg based on distance (see AIM 5-3-7, paragraph b). Most holds depicted on GPS instrument approaches in the US now have a specified distance for the outbound hold leg, instead of a timed leg.
Longer Answer:
The traditional hold leg distance is determined by timing. See AIM 5-3-7 § j. 4.:

4. Timing.
(a) Inbound Leg.
(1) At or below 14,000 feet MSL: 1 minute.
(2) Above 14,000 feet MSL: 11/2 minutes.
NOTE- The initial outbound leg should be flown for 1 minute or 1 1/2 minutes (appropriate to altitude). Timing for subsequent outbound legs
should be adjusted, as necessary, to achieve proper inbound leg time.
Pilots may use any navigational means available; i.e., DME, RNAV,
etc., to ensure the appropriate inbound leg times.
(b) Outbound leg timing begins over/abeam the fix, whichever occurs
later. If the abeam position cannot be determined, start timing when
turn to outbound is completed.

In years past this was common for all holds, unless otherwise specified by the published hold instructions, or by ATC. All otherwise unspecified holds were assumed to be timed holds, including for GPS approaches. I only remember a few distance-defined holds in my local area from 10 years ago; now all those holds associated with GPS instrument approaches are distance defined.
Which brings us to the AIM 5-3-7 § j. 5. (emphasis on the last two sentences is mine):

5. Distance Measuring Equipment (DME)/ GPS Along-Track Distance (ATD). DME/GPS holding is subject to the same entry and holding procedures except that distances (nautical miles) are used in lieu of time values. The outbound course of the DME/GPS holding pattern is called the outbound leg of the pattern. The controller or the instrument approach procedure chart will specify the length of the outbound leg. The end of the outbound leg is determined by the DME or ATD readout. The holding fix on conventional procedures, or controller defined holding based on a conventional navigation aid with DME, is a specified course or radial and distances are from the DME station for both the inbound and outbound ends of the holding pattern. When flying published GPS overlay or stand alone procedures with distance specified, the holding fix will be a waypoint in the database and the end of the outbound leg will be determined by the ATD. Some GPS overlay and early stand alone procedures may have timing specified.

See also AIM Fig 5-3-7 and the associated note, which address the type of distance holds found on GPS approaches:

NOTE-
The inbound course is always toward the waypoint and the ATD is zero at the waypoint. The end of the outbound leg of the holding pattern is reached when the ATD reads the specified distance.

The holds found on GPS approaches will generally be distance based. The AIM states that some might still be time based, but I am no longer aware of any such holds in actuality. Every approach that I know of that used to have a time based hold on a GPS approach now has a distance based hold.
All holds should be flown as published or as instructed by ATC. If ATC does not instruct you otherwise, you are expected to fly the hold as published. In this case, that means you are expected to fly the hold as a distance-based hold. If you are not sure how you should fly the hold, ask ATC. They will provide you with the complete holding instructions if requested. See AIM 5-3-7 § b.:

b. If the holding pattern is charted and the controller doesn't issue
complete holding instructions, the pilot is expected to hold as
depicted on the appropriate chart. When the pattern is charted, the
controller may omit all holding instructions except the charted
holding direction and the statement AS PUBLISHED; e.g., HOLD EAST AS
PUBLISHED. Controllers shall always issue complete holding
instructions when pilots request them.


What kind of input is used by NASA's TASAR?

The answer is "All of the above." The left hand side of this slide from a NASA Powerpoint deck pretty much covers your question.

The full slide deck from the presentation can be seen here.


Why was the Yak-9U covered with Bakelite?

The Bakelite finish was for the wooden parts/variants.

Bakelite back then was a novelty, its usage in airplanes strengthened the wood, made it moisture resistant, and offered a smooth aerodynamic light-weight finish.

It was also highly flammable:

  The LaGG-1 was built with highly flammable delta-drevesina (delta wood), plywood sheathing, and bakelite ply, and burned so easily that the pilots sarcastically joked that LaGG in Russian stood for Lakirovannyi Garantirovannyi Grob (varnished guaranteed coffin).

The LaGG-3 article on Wikipedia offers more details on this method of construction:

  [The] airframe was almost completely made of timber, with the so-called delta-lumber (a wood-plastic composite composed of very thin, 0.35 to 0.55 mm, wood veneer and phenol formaldehyde resin [Bakelite], baked at high temperature and pressure) used for the crucial parts. This novel construction material had tensile strength comparable to that of non-hardened aluminum alloys.

Sources: MOISTURE RESISTANT FINISHES FOR AIRPLANE WOODS (NACA, 1920), and Russian Aviation and Air Power in the Twentieth Century By John Greenwood.


How do I find a plane's history when booking a flight?

Unless you are booking at the very last minute, no there is no way to find out which particular aircraft you'll be on until you're strapped in. The airline themselves plan in advance but as soon as one plane needs unexpected maintenance, or is excessively delayed, the schedule is thrown out the window. For this reason more than anything no airline to my knowledge publishes this schedule.

Once you are at the gate you might be able to see the aircraft registration. If you google that you can see if it has been in any serious incidents, when it was delivered and how old it is. You won't be able to find out how many repairs it has gone through, only the airline has that (hint: the answer could be hundreds of times if you're counting minor issues).


Despite the lessons from DC-10 planes in 70s, why didn't Boeing ensure their cargo doors didn't fail even until the end of the 80s?

Most probably because the failure modes were very different. In the DC-10 case the door could appear closed even though the locking mechanism was not properly engaged. On 747 that was not a problem; instead the electric motors opening the door had enough power to break the locking mechanism if electric power somehow made it around the switch that was part of the locking mechanism.

And then, 2 years are not really enough to analyse a problem like this, develop a fix, test it and deploy it. The NTSB investigations alone often take longer than 2 years.


Can TAS at different altitudes be calculated if only one performance point is given?

If you keep 5,200 rpm at 6,000’, the engine will be producing slightly less power due to density altitude. There will also be slightly less drag so the speed will only drop about 1-2 knots. Because the engine is producing less power, fuel consumption will be slightly less and range will also increase.

The performance figures for a Cessna 150 can give you an approximation of how the numbers change with altitude.


What is the maximum G load a 747 can withstand during an emergency course reversal?

It depends on how you define :withstand". China Airlines flight 006 experienced vertical load factors of up to 5.1 g on 19 February 1985. The aircraft could be landed safely and there were no fatalities, but there was considerable damage:

Image source

From the NTSB incident report:

  The wings were bent or set permanently 2 to 3 inches upward at the wingtips; however, the set was within the manufacturer's allowable tolerances. The left aileron's upper surface panel was broken and the trailing edge wedge was cracked in several places.

The maximum load factor an aircraft can be subjected to is a function of time. Two cases are determined for civil aircraft:

Limit load factor. For transport aircraft weighing more than 50,000 lb
(22,680 kg) this load factor is equal to 2.5, while for lighter aircraft it is a function of the weight.
Ultimate load factor = 1.5 times limit load factor, is the higher of the gust and the manoeuvre load factor.

The load factors are determined in accordance with the airworthiness regulations 14 CFR part 23.341 and 14 CFR Part 25.341. Damage tolerance of the airframe and the consequences of metal fatigue are stated in 14 CFR part 25.571.

The B747SP of the incident is an aeroplane that was designed and constructed in the 60s/70s, before Computer Aided Design and engineering were wide-spread, and the structures were designed with analytical mathematics and knowledge from experience, then tested for limit loads and ultimate loads. The more the design stresses can be modelled on a computer screen, the closer the wing ultimate load can be to 150% of limit load. Older aeroplanes did not have these modelling tools, and wings could end up to be stronger and heavier than they needed to be. Something that everybody applauds, but nobody wants to pay for with a higher ticket price.

A video of the B777 shows how the static testing for ultimate load is done: an actual wing is bent until it breaks. It is not a test of wing flex, it is a test of static strength.

The particular 747 of the incident had a wing designed for an MTOW of 378,000 kg, while actual MTOW of the 747SP was 320,000 kg: an extra load factor of 1.18. Fuel in the wing tanks provides extra bending relief, not for the ailerons though..


Running the numbers from RedGrittyBrick's answer, there appear to be 36 active 747-200s out of 393 built (according to Wikipedia). Of the 36, 9 are passenger planes, 22 freight (including 6 converted from passenger planes, marked *), 3 combi (passenger and freight), and the two VC-25As ("Air Force One").

The active aircraft are as follows, with tail numbers included so you can look for photos.

Aerospace One: 1 freight (SX-ASO), 1 combi (SX-ASC)
AHS Air International: 1 freight (AP-BIO)
Cargo Air Lines: 1 combi (4X-ICM)
Caspian Airlines: 1 freight (EP-CQA)
Iran Air: 3 passenger (EP-IAG, EP-IAH, EP-IAI), 1 combi (EP-ICD)
Jet Star: 1 freight (ER-BBS)
Kabo Air: 3 passenger (5N-DKB, 5N-JRM, 5N-MAD)
Kalitta Air: 2 passenger (N715CK, N793CK), 4 freight (N704CK, N746CK, N794CK,* N795CK*)
Kam Air: 1 freight (4L-TZS)
Midex Airlines: 3 freight (A6-MDG, A6-MDH, A6-MDI)
Orient Thai Airlines: 1 passenger (HS-UTC)
Rayyan Air**: 2 freight (AP-BKI, AP-BKS*)
Saha Airlines: 2 freight (EP-SHB, EP-SHH)
Saudi Arabian Airlines: 1 freight (HZ-AIU)
United States Air Force: 2 VC-25A (82-8000, 92-9000)
Uni-Top Airlines: 3 freight (B-2448,* B-2450,* B-2462)
Veteran Avia: 1 freight (EK74799*)
Vision Air International: 1 freight (AP-BIV)

* Built as passenger and converted to freight.
** Not to be confused with Ryanair! :-)

There are also several stored aircraft, including the Rolls-Royce test plane you mention in the question.

Thanks to fooot for explaining that BSF denotes "Boeing Special Freighter", a passenger plane converted to freight use.


Why not use the yoke to control yaw, as well as pitch and roll?

The modern control yoke is directly derived from the "joystick" control that became standard on aircraft in the days when Glenn Curtiss personally ran the company that was the main competitor to the Wright brothers.

After inventing aileron control (the Wrights were still using wing warping at the time -- this was before 1910), Curtiss needed a way to control movement of the ailerons, and subsequently of the rudder.  The original 1903 Wright Flyer had the wing warp controlled by sliding the pilot's platform (a flat surface, on which the pilot lay prone) right and left, and coupled the rudder, so that roll and yaw were inseparable.  Curtiss decoupled them, and needed to add a third control -- and since he was also sitting upright, even in his first airplane, his feet were available.

Running the elevators and ailerons on the control stick was obvious, and it was equally simple to put one's feet on a bar that directly operated the rudder -- and this layout became the standard almost instantly.  Even the Wrights adopted it before they demonstrated their Flier to the Army.

Over time, there have been a few examples of variations.  Airplanes that brought back coupled rudder and aileron, like the Ercoupe, let the pilot fly with "feet flat on the floor" -- and it seems to me there was at least one design, from the biplane era, of a transport aircraft with rudder operated much the way you describe; a control wheel mounted on a joystick, with stick movement controlling roll, and wheel rotation controlling yaw.

The fact this has only appeared in a very small number of designs suggests that, as noted in a comment, it's a bad idea to change something that's been long standardized -- yet, we have a good number of aircraft, ranging from sailplane to jet fighter and large transport, that use "sidestick" -- in which, in the transport case, the pilot in command actually flies with his left hand, while the copilot flies with his right.  Joysticks continue in wide use as well, especially in smaller or higher performance aircraft, or those with ejection systems.

The other, and I believe the main reason we don't see control schemes like what you describe is that it becomes impossible to maintain precise, separate control of roll and yaw.  When the same pair of hands are doing both jobs, the brain will mix them together, or in trying not to, will reverse mix (leading to a forward slip or a skid, the latter widely considered very hazardous at low altitude and speed).  If you have an aircraft in which it's difficult to avoid mixing either adverse or proverse rudder while applying aileron, it'll be difficult to land or take off in crosswinds, hard to maintain a precise final approach, and nearly impossible to fly high precision maneuvers (like air to air refueling or tight formations).


How can I tell the difference between Spitfires and Hurricanes in photos?

There are quite a lot of differences, some more subtle than others, but I tend to find this is the best angle for identification: the side view. Although as we'll see later in this answer, the top/bottom view has a fairly obvious difference, and there's a clue that we can use to identify from the front or rear

So what are you looking at?

On the left is the Hurricane. It's slightly larger than the Spitfire, although that's not always a great help from distance. Perhaps more usefully, the fuselage is fundamentally different shape:  I'll elaborate on this in several areas where we can directly compare.

Firstly, the rear fuselage. At first glance the two are very similar, but the Hurricane has a much more pronounced "drop" to the tail, while the Spitfire's is a "rise".

What do I mean by that? Follow the line of the top of the cockpit canopy: the Hurricane's fuselage behind the canopy drops away, while the bottom of the fuselage is relatively flat. On the Spitfire, it's reversed - the top of the fuselage follows the line of the canopy, while the bottom comes up to meet it. It's a subtle difference at first glance, but once you've seen it once it's a very clear distinction. When looking at the Hurricane's rear fuselage, it almost appears to have a "dog leg", where the rearmost area drops in relation to the middle of the aircraft. The Spitfire's follows a much more continuous line

The Spitfire is also clearly much more sleek - it's a "pencil" shaped fuselage, long and thin and curvy. The Hurricane is more blunt and "solid".

Other differences? Look at the tail. The Spitfire's is relatively small and curves upward from the top of the fuselage in a smooth curve, while the Hurricane's comes off at a sharper angle. Similarly the Hurricane's horizontal stabilizer is higher - almost in line with the top of the fuselage.

The Engine cowling shape, as with the cockpit, is different: where again the Spitfire's continues a nearly straight line from the bottom of the cockpit, the Hurricane's has a distinct curve.

If you can get closer, you will also note that the Hurricane's fuselage is almost "ridged" - it's a metal frame with a fabric covering, and that gives it a bumpy appearance, vaguely visible on the above photo.

What about if you can't get a side view, though? Here's the Spitfire (below) and Hurricane (above) from the front... but you can see the same from the rear

Well from the front, there's a single very nice clue under the fuselage: the radiator housing: that box-like structure hanging from the bottom of the plane. The Hurricane has one, and it's on the centre of the fuselage. The Spitfire's is not, it's under the right wing. On some later models, there are two, one under each wing.

The next photo is included mostly for the wing shape, but the aforementioned radiator boxes are visible too: from this, we can tell the Spitfire is a relatively late war model: a Mk IX (9) onward: although there are other subtle clues that suggest this is a much later model... the 5 bladed propeller indicates a Griffon engine, so a Mk XIV (14) or later. Anyway, we can see the Hurricane's single centre radiator, and the Spitfire with one under each wing

And finally, how about the bottom? Well, the Spitfire's wing is extremely distinctive: it has an "Elliptical" wing, shared with only one or two other aircraft. Once you can recognise the Elliptical wing, you can recognise the Spitfire very easily in flight. The Spitfire's wing, particularly the trailing edge, is very curved compared to most other contemporary aircraft. The Hurricane's wings are much more conventionally shaped, with both leading and trailing edges being straight (a trait shared with aircraft like the Typhoon/Tempest, P-51, Me109, A6M "Zero" and most other aircraft from the WW2 era)

(source: modelingmadness.com)

Late War Spitfires (the above is a Mk 22) are even more distinctive: they have a "bubble" canopy that protrudes entirely from the fuselage.


How are military jets given official names?

Typically for modern US aircraft, since the military pays the contractor for the aircraft's development, so they are paying for it, and get to name it. This article says the USAF named the F-35 as the "Lightning II". However, the reality is much more likely, the F-35 Joint Program Office (the JPO), named the aircraft, given it international status and being a joint aircraft, and the announcement was made by the USAF. The JPO, being a joint office, always has a Program Executive Officer (PEO), and a Deputy, from both the USAF and USN (alternating positions). The F-22 was likely named by the USAF F-22 project office, which was based at Wright-Patterson Air Force Base, Dayton, Ohio. See here.

However, this isn't always the case, at least historically. For example, the Lockheed Orion & Hercules,  (and the Constellation) follow a tradition of Lockheed of naming their aircraft after celestial objects, stated here and here. The A-12 was also named by flight crews as the Cygnus (swan), another constellation, to follow this pattern. So, some US military aircraft, in the past, have been named by the manufacturer.

As another example, the F-111 is believed to be the only US aircraft to go through its service career without being officially named. On its retirement, the USAF designated it the "Aardvark". While the name was made official by the USAF, it came from the term the crews used for it.

  Its American crew called the F-111 the Aardvark. It was a good name. Like the South African aardvark, the F-111 was a solitary night hunter. Like the aardvark, it rooted in the dirt, guided by excellent senses. And like the aardvark, it had very long range. For much the same reasons, Australians called it the Pig.

So, while in the past, sometimes the manufacturer named the aircraft, sometimes the crews, it would seem, today, the US government, through their military force, chose the name.


Would increasing the number of wheels of a Jumbo reduce the braking distance?

Typically, a little gain is obtained.

Larger airplanes use anti-skid technology. Anti-skid works by modulating brake pressure to ensure the tires never skid. It's important to understand the relation between a tire's load, brake pressure, and actual retarding force. First, look at this image :

It shows how as you increase pressure and the wheel starts slipping a bit (turning at a rate slightly slower than when free rolling), the friction coefficient rises sharply. Then after the 10% slippage, the peak coefficient is reached and thus the retardation force reduces. Anti-skid aims to keep the slip raitio as close to 10% as posssible. Therefore the retardation force is maximized.

The brakes of airplanes are strong enough to fully lock the tyres, but this is detrimental (results in 100% Slippage, so maybe 20% retardation force loss). So they can and do maintain optimal slip, therefore using the entire available 'grip'.

Now what happens to this picture if you add wheels?

If the added wheel is not braked (like the nose wheels are) then you lose braking. Indeed, the braked wheels will have a reduced vertical load, so they will provide less retardation force. It's quite useless.
If we add braked wheels then we see the tyiniest bit of gain. Let's see why.

First look at this picture of tire load sensitivity (this one shows lateral force while cornering, but longitudinal force while braking exhibits the same features):

What is important to note, is that as a tire gets more loaded, its capacity to generate friction decreases.

Now for a jumbo: When 20 wheels share 500 tons of load, each tire sees 25t. with a default friction coefficient of 0.8, each tire generates 20t retarding force, so total of 400t retarding force.

Let's add 2 wheels in there. Now each wheels sees 22.7t of load. Their friction coefficient could now rise to 0.82, therefore providing 18.6t, for a total of 410 tons. Certainly far of the 40t that could be naively expected from adding 2 braked wheels! Only the load sensitivity nets us a gain.

It then becomes the usual game of trade-offs. How much mass is spent on bigger landing gear and wheels and additional brakes, versus the gain of harder braking (and thus even stronger landing gear legs?)

Apparently the Airbus guys decided the trade stopped at 20 wheels (because 25t of load on a single tire is the maximum the ground could handle) but they didn't even bother to brake them all, if I remember well only 4 of the 6 wheels of the main boggies are braked! So if you wanted to improve brake efficiency:

Install better tires on braked wheels
Brake the non-braked main wheels
Make some smart aero changes to increase aero downforce & drag
Add braked wheels (and prepare to house them in the main body... good luck!)
Brake the nose wheels (but that would be terribly hard because it was never designed for that)


How do you open and get a IFR clearance while in the air?

There is one example in the AIM used for transitioning from VFR to IFR, and it how I've always done it:

  AIM 5-2-5. Abbreviated IFR Departure Clearance (Cleared … as Filed) Procedures

  EXAMPLE-
  "Los Angeles center, Apache Six One Papa, VFR estimating Paso Robles VOR at three two, one thousand five hundred,
  request IFR to Bakersfield."

Reference: 5−2−5. Abbreviated IFR Departure Clearance (Cleared … as Filed) Procedures (13 MB PDF)

Notice that they specifically say "VFR" right before their current location and also use the word "request" to make it clear what they are looking for.  I would change your request to:

  Tampa Approach, Cirrus 123AB, VFR 5 miles southeast of Tampa Exec
  at 1000 feet, request IFR to Ft. Lauderdale Exec


I would like to insure my foreign registered aircraft in the USA

You could do either or neither.

I assume you are flying a small, piston-engined aircraft. Any insurance company that insures turbine powered aircraft would have provisions for this. I don’t specialize in aircraft insurance. Having been in insurance for 20 years, I know that anything and everything can be insured for the right price. If your insurance company won’t do it, there are others that will. You just might not be willing to pay the price the insurance company requires.

The question you might ask yourself is how do people who ferry aircraft across the pond insure the aircraft? If you are planning a cross-Atlantic flight, you might want to contact an experienced, professional company to help you plan it. You have to think of more than insurance. Communication, water safety/survival and egress, auxiliary fuel planning, weather, sovereign airspace entry, enroute landing airports, customs, and other items need to be considered.

An alternative is to rent an airplane or airplanes here in the US. I have run into a few of Brits, Germans, Aussies and New Zealanders who have done that. They made it seem surprisingly easy and something they did on a regular basis. Some annually. I have even checked into doing it in South Africa. It would have been simple with the renting organization even arranging for validation of my US pilot certificate for flight use in South Africa.


Who is responsible for airspace separation when an IFR flight is cleared for a visual approach?

Visual approach responsibilities
§5-5-11
Pilot's end:

(3). The pilot must, at all times, have either the airport or the preceding aircraft in sight.

Controller's end:

(3). Provide separation except when visual separation is being applied by the pilot.
(7). Continue flight following and traffic information until the aircraft has landed or has been instructed to change to advisory frequency.

—AIM

For coordination with/between nonapproach control towers
§2-1-14 Coordinate Use of Airspace

(a). Ensure that the necessary coordination has been accomplished before you allow an aircraft under your control to enter another controller’s area of jurisdiction.
(b). Before you issue a control instruction directly to a pilot that will change the aircraft’s heading, route, speed, or altitude, you must ensure that coordination has been completed with all controllers whose area of jurisdiction is affected by those instructions unless otherwise specified by a letter of agreement or facility directive. If your control instruction will be relayed to the pilot through a source other than another radar controller (FSS, ARINC, another pilot, etc.), you are still responsible to ensure that all required coordination is completed.

§2-1-16 Surface Areas

(a). Coordinate with the appropriate nonapproach control tower on an individual aircraft basis before issuing a clearance which would require flight within a surface area for which the tower has responsibility unless otherwise specified in a letter of agreement.
(b). Coordinate with the appropriate control tower for transit authorization when you are providing radar traffic advisory service to an aircraft that will enter another facility’s airspace.
(c). Transfer communications to the appropriate facility, if required, prior to operation within a surface area for which the tower has responsibility.

§2-1-17 Radio Communications

(a). Transfer radio communications before an aircraft enters the receiving controller’s area of jurisdiction unless otherwise coordinated or specified by a letter of agreement or a facility directive.

—ATC (JO 7110.65W)

Short version of the above
ATC (terminal or tower) will need to instruct an altitude and/or heading so you don't deviate and surprise/buzz a Class D you're not going to. Otherwise they'll need to transfer the comms, which I'm sure they don't want to. Unless there's a prior agreement between the different facilities.
Pilot needs to have preceding traffic or field in sight.
Terminal ATC needs to keep an eye on all traffic and provide traffic information, until they handoff the pilot to tower or CTAF.


Where can I find the latest METAR and TAF for RPVK / Kalibo International Airport?

You can find the latest METAR for RPVK here: https://tgftp.nws.noaa.gov/data/observations/metar/stations/RPVK.TXT and TAF here: https://tgftp.nws.noaa.gov/data/forecasts/taf/stations/RPVK.TXT

Remember to look at the publication date/time, since it may not be very recent.


What should I do with fuel drained from the sumps during preflighting?

The FAA issued an Aviation Safety Program publication called All About Fuel which talks about fuel preflight, including sumping fuel.  It contains the following:

  Preflight Action     As pilot in command, you have the responsibility to determine that your aircraft is properly serviced.
  Check your aircraft before each flight and be sure you have the
  correct type of fuel. This practice may save your life! Take the time
  to inspect your aircraft thoroughly. Good preflight procedures:

  Be sure all of the fuel and oil tank caps and covers are installed and secured properly after you visually check the fluid level.
  Observe the color and odor of the fuel as you check the tank.
  Draw a generous sample of fuel from each sump and screen drain into a transparent container. Check for the presence of water, dirt, rust
  or other contaminants. Unless you have the proper kind of fuel tester
  (e.g., GATS jar with intact fuel strainer), do not attempt to save the
  fuel drained from the sumps by pouring it back into the tank. Note: If
  you are not equipped to safely pour the drained fuel back into the
  tank, please be sure to dispose of it in accordance with EPA
  regulation.
  Check that each fuel tank vent is clear of restrictions; i.e., dirt, ice, snow, bent or pinched tubes, etc.

Any FBO that sells fuel should have a way to dispose of it.  Some of them make it more obvious than others by putting sump barrels out on the ramp, but ask them what to do with it before you go out to the airplane and they should be able to help you out.  For environmental reasons, you definitely shouldn't dump it on the ground, because even if it does evaporate, it will come down somewhere.  At some airports you can even get in a lot of trouble (and have to pay a big fine) by dumping fuel on the ramp.  Don't take a chance!


Helicopter tail horizontal stabilizer angle

The stab angle influences the pitch attitude in cruise, allowing the body of the machine to be flatter (more nose up) than it would be without it, by pushing down on the tail with speed.  It also dampens pitch oscillations of the body under the rotor disc.  A designer will come up with a stab area and incidence that is estimated to provide the necessary down force for a desirable cruise attitude for a particular machine, then adjust as required during flight testing.

The Blackhawk takes it much farther; the stab is a moveable control surface that allows attitude control over a very wide speed range.


Why is the shape of the cargo compartment similar in large aircraft?

The answer lies in the existence of something called a Unit Load Device (ULD) -- basically a cargo pod for aircraft that's the equivalent of the shipping pallet.
ULDs allow oddly-shaped cargo (bags, assorted-size boxes, etc.) to be loaded efficiently in a standard volume and easily secured for flight (using hold-down lugs in the floor).

The shape of the cargo deck is designed to pack in as many ULDs as possible:

and as you can see from the cross-section the sloping sides on the bottom are a concession to the circular cross-section of the fuselage/pressure vessel.

Some other advantages of ULDs as they pertain to airline operations and baggage loading are described over on this question.


How autonomous are commercial passenger airliners?

They're not really autonomous, they're mostly automated.

I'll lift this description from Wikipedia despite being written for cars (emphasis mine):

  Autonomous means self-governance. Many historical projects related to vehicle autonomy have been automated (made to be automatic) due to a heavy reliance on artificial hints in their environment, such as magnetic strips. Autonomous control implies satisfactory performance under significant uncertainties in the environment and the ability to compensate for system failures without external intervention.

While most autopilots will fare fairly well under "significant uncertainties in the environment" (read e.g. "severe turbulence"), they are not equally capable "to compensate for system failures without external intervention". Even the Airbus' autopilots revert authority to the pilots if the system degrades.

Even knowing the destination airport, they need a pilot to insert the flight plan into the flight computer, they cannot compute it by themselves.

They cannot take evasive action in case of dangerous situations, but they can only warn the pilot (see EGPWS and TCAS RAs).

They cannot even properly recognize bad weather (say, a thunderstorm) and eventually plan diversions around it.

They could not land an aircraft by themselves, as they generally lack control over the aircraft configuration.

What they can do is blindly follow the flight plan given, so they are automatic, but not autonomous.


More than one runway with the same heading. How are they labelled?

Left, right and centre.

For example, Heathrow has 27 left (27L) and right and 09 left (09L) and right.

See here for the airfield chart.

You can see the numbers close to the end of the runways.

Here's an example for an airfield with a 34 left runway.

If there are more than three runways more or less parallel, one or more runway numbers will be shifted by 10 degrees, e.g. 08L, 08C, 08R, 09R.

From the Wikipedia article on runway numbering:

  At large airports with four or more parallel runways (for example, at
  Los Angeles, Detroit Metropolitan Wayne County, Hartsfield-Jackson
  Atlanta, Denver, Dallas-Fort Worth and Orlando) some runway
  identifiers are shifted by 10 degrees to avoid the ambiguity that
  would result with more than three parallel runways.

  For example, in Los Angeles, this system results in runways 6L, 6R,
  7L, and 7R, even though all four runways are actually parallel
  (approximately 69 degrees). At Dallas/Fort Worth International
  Airport, there are five parallel runways, named 17L, 17C, 17R, 18L,
  and 18R, all oriented at a heading of 175.4 degrees.

  Occasionally, an airport with only 3 parallel runways may use
  different runway identifiers, for example when a third parallel runway
  was opened at Phoenix Sky Harbor International Airport in 2000 to the
  south of existing 8R/26L, rather than confusingly becoming the "new"
  8R/26L it was instead designated 7R/25L, with the former 8R/26L
  becoming 7L/25R and 8L/26R becoming 8/26.