How do banner tow planes coordinate with air traffic control?

An aircraft conducting a banner towing operation must have prior approval (written letters of authorization) from any ATC authority they will be conducting operations prior to the banner tow operation. A copy of this letter must be carried on board the aircraft. The local FSDO must also be involved (which will handle the 7711-2 application).

The first thing you need to do is to file Form 7711-2 "Certificate of Waiver or Authorization Application" detailing all regulations which will be violated (minimum safe altitudes/separation, etc).

From the INFORMATION FOR BANNER
TOW OPERATIONS FAA/FS-I-8700-1:

  Conduct all banner tow operations in VFR weather conditions defined by Title 14 of the Code of
  Federal Regulations (14 CFR) part 91, section 91.155. Operations shall be conducted only between
  the hours of official sunrise and official sunset.
  The certificate holder shall obtain the airport manager’s approval to conduct banner tow operations
  at each airport of intended operation.
  Notify appropriate airport officials in advance when banner tow operations will be in close
  proximity to each non-towered airport.

  ...

  Operations outside the geographic area of the issuing FSDO will be coordinated with the appropriate
  jurisdictional FSDO in advance and the operator will comply with all special provisions imposed by
  that office.


Procedure turn/hold required on this approach?

If you start the procedure at ROBUD and your clearance does not include "cleared for straight in approach", then you are expected to do a procedure turn in the hold. In real life the first thing to do in such situation would be to query the controller "confirm we are cleared for straight in approach", they are very likely to forget it also.

In my opinion, this is an example of an error on the FAA chart, which is missing noPT annotation on the leg from ROBUD to MOFTE. That annotation is present on a Jepp chart. I've seen these kind of errors in the past and FAA is usually pretty good in correcting them, so go ahead and ask them at Aeronautical Inquires.

.


Are fighter jets vulnerable to .50 caliber gunfire?

By .50 caliber, I believe you are referring to the .50 BMG cartridge.  The answer is yes, you could shoot down a jet fighter using such a round and plenty of jet fighters, such as MiG-15s, have been felled using that round during the Korean War.

In some respects the .50 BMG is a superior round to modern cannon rounds for shooting down jet fighters.  It's a small, fast round with good range, muzzle energy and penetration capability and can be fired at high rates, saturating sections of the sky with rounds, particularly useful for high off-angle snapshots in ACM.

In regards to penetration power, even a .22LR round could punch through the skin of a modern fighter.  The structure has to be kept light for weight and performance reasons.  Armor on fighters is almost unheard of, save for some plating on flight crew seats.  One exception to this is ground attack aircraft such as the A-10 or SU-25 which do have armor around the cockpit to protect the pilot at low levels.  The rest of the aircraft does not have armor and relies more on structural integrity and redundancy to protect the aircraft from ground fire.


Why don't we simulate similarity parameters simultaneously in the same wind tunnel?

It would be great if we could match all parameters at once. But that would require a tunnel large enough to accommodate the full size airplane and powerful enough to match the actual flight speed. The reality is that we cannot in most cases.
We have some answers here on windtunnel testing. They should cover the basics:

How are wind tunnels used with scale models?
What are some specific benefits of cryogenic wind tunnels?
How is windspeed scaled in wind-tunnel tests?

The most important similarity numbers are the Reynolds number and the Mach number. Both grow linearly with flow speed, so it helps to match flow speed. In case of the Reynolds number, the other parts of it are the length of the flow path and the viscosity of the fluid. If we use air, which is plentiful and free, we also need to match the actual size so that the Reynolds number matches the original. The Mach number also depends on the speed of sound in the fluid, which in turn depends on temperature.
It is possible to match both Reynolds and Mach number in super cold tunnels using a pressurised gas like nitrogen. This lowers the required gas speed so the tunnel needs less power to run and produces realistic results with smaller models. The expense of building and operating such a tunnel is immense, though.


The composition of total Drag as it is shown below:

Thanks to DRAGBUSTERS... This document can solve this question, and analyses the drag in detail.

  Profile Drag Definition:
  Profile Drag is the drag incurred from frictional resistance of the blades passing through the air. It does not change significantly with angle of attack of the airfoil section, but increases moderately as airspeed increases.
   Taken from here.

Definitions of profile drag as they are in dictionaries:

  The portion of the wing drag that is due to friction and turbulence in
  the fluid and that would be absent if it were nonviscous

  The part of the drag on an aerofoil or aircraft which arises directly
  from its profile and from skin friction (i.e. the part not
  attributable to lift).

By reading this...(in fifth par.)

  Form Drag Definition: Drag which depends on the shape of the aircraft, is called form drag.

The following definition has been taken from here.

  Profile Drag or, sometimes called form drag, is the drag
  caused by the separation of the boundary layer from a surface and the
  wake created by that separation. It is primarily dependent upon the
  shape of the object. Form or pressure drag is caused by the air that is flowing over the aircraft or airfoil.

And finally, the most commonly types of drag encountered are,

  Parasitic Drag, composed of

    Form Drag, which is the result of the aerodynamic resistance to motion due to the shape of the aircraft,

    Skin Friction Drag, which is due to the smoothness or roughness of the
    surfaces of the aircraft, and

    Interference Drag, which may occur where surfaces with different characteristics meet (e.g. wing and fuselage)

  Induced Drag, which is a secondary effect of the production of lift,and

  Wave Drag which comes into play when shock waves are developed close to the surface of the aircraft in transonic and supersonic flight.

  Taken by this Skybrary Article which describes very nicely the types of drag.


How much g-force is experienced in a 45° turn?

The formula for the load factor $n_z$ in a turn is

$$n_z = \frac{1}{cos\phi}$$

where $\phi$ is the bank angle. This makes the load factor in a 45° turn 1.414 or $\sqrt{2}$.

Since Michael correctly mentions the simplifications in his comment, let me expand the formula above. In case of a climbing turn, the load factor depends on the coordinate system used. If it is measured in airframe-fixed coordinates, the load factor will be split into a z-component ($n_z$, pointing down) and an x-component ($n_x$, pointing fore- or backward, depending on the aircraft's pitch attitude $\Theta$; nose-up is positive):
$$n_x = -\frac{sin\Theta}{cos\phi}$$
$$n_z = \frac{cos\Theta}{cos\phi}$$

For an uncoordinated turn the value needs to be modified further with the relationship between bank angle change for a given sideslip angle, which is aircraft-specific.


How minimum runway length is calculated for PAC P-750 XSTOL?

You can't, at least not on the basis of the POH you linked. Taking off with 0° flaps for that aircraft is outside the POH limitations chapter.
2.20 Flap Limitations:

Approved flap ranges.
TAKEOFF FLAP: 20°
LANDING FLAP: 40°

4.27 Amplified Procedures - Normal Takeoff):

A wing flap setting of 20°  is recommended for all takeoffs. 20° flap
will provide the best takeoff performance. The Normal Takeoff
technique is to be used for Short Field operations and is the
technique used to derive the performance data in Section 5.


What is a general rule for crosswind correction, especially when landing?

What I have learned during my commercial flight training is making use of the speed number.
Take your TAS, devide it by 60. This is your speed number.

Now take you XWC (crosswind component).
Devide the XWC by your speed number. This is the amount of degrees you should crab to stay on track (wind correction angle)

Lets use an example:

We are flying in a C172 at 120kts TAS.
XWC is 18kts from the left.
120 devided by 60 is 2, so our speed number is 2.
18kts wind devided by 2 is 9. Now adjust your heading by 9 degrees to the left (into the wind), and you should stay on track.

Worked perfectly fine for me so far.
Hope it helps! Cheers


You can either cool the air to reduce it's capacity to hold water, or you can add water to the air. Either way will eventually make the air saturated

You can either make the bucket smaller, or you can add water in the bucket. Either  way you will eventually make the bucket spill ...


What is the easiest way to update sectional charts with bulletin changes between printings?

...or any other online source that I have found.

Sites like VFR map, Foreflight and the such get the maps from the freely available digital downloads the FAA produces. These downloads coincide with the physical printed versions and update along with them.

The FAA (at least partially) explains what to do right on the link

  ...why we publish the Aeronautical Chart Bulletin in the back of
  each Airport/Facility Directory (AFD) every 56 days and why it is
  important that you consult the Notices to Airmen (NOTAMs) prior to
  each flight. FAA regulations state that a pilot must be familiar with
  all available information concerning a flight. This includes having
  up-to-date charts and keeping them current...

The main point here is to check the available supplements and make sure you have all the up to date information relevant to your flight.

But lets talk about this in practice a bit because its important to understand what changes and what you should mark. NOTAMS often inform you of things like VOR outages and runway closures. In some cases these are permanent but in many cases they are temporary due to construction, maintenance or calibration. You should not go crossing out VOR's or Airports on your chart if they are only going to be down for potentially the duration of your flight that day (as relevant to you). With that in mind you should notate them as appropriate to your flight.

In many cases if the the runway closure or VOR outage is not along your route or a nav aid you plan to use it is of no relevance for you for that flight anyway. When going VFR you may even hear the briefer (if you call in) ask "would you like to hear about nav aid outages in your area". You can easily respond no as you may not be using VOR's to navigate that day.

The key is to make sure you have all the information on your destination and your posible alternate fields along the route and any potential deviation plans. You don't need to keep the whole span of the chart up to date, thats why they reprint them.

If your flight school allows you may want to look into something like foreflight or garmin pilot which makes sure your stuff is always up to date.

FWIW when i used paper charts I used to write all over them and often replace them before they expired because they were written all over.


What benefit does a group get from being an FAA recognized flying club?

If the airport you're based at has federal grant obligations (basically if they've taken money from the Airport Improvement Program) then being a "flying club" by the FAA's definition entitles you (as a group) to the same rights as any other operator at the field (like the right to fuel your aircraft with fuel you buy yourself & have trucked in, or the right to do maintenance on the aircraft), subject to the same rules and regulations the airport lays down for all operators.

The biggest material difference is that "flying clubs" aren't considered to be "commercial" ventures by the FAA (and by extension grant-obligted airports).

As an example, let's say you have a flying club & you "charge" $50/hr for the use of one of the planes, and your airport management decides that since you're charging money for the use of the planes you're a commercial venture, and need to have commercial insurance and the like.

If you meet the FAA definition of a "Flying Club" and the airport has federal grant obligations you can ask your local FSDO to step in and effectively tell the airport management to get stuffed - as a flying club you're treated more like an individual than a commercial business, and the airport is not allowed to impose those commercial requirements on you.
If you don't meet that definition the FAA won't intervene on your behalf (as far as they're concerned you are a rental outfit / commercial FBO at that point and the airport is correct in treating you as one).

Note that you can still call yourself a "flying club" even if you don't meet the FAA's definition -- I belong to a flying club that has no aircraft (we're just a bunch of folks who like to talk about flying and organize the occasional fly-out event or safety seminar - some of us own planes, and some rent from local FBOs), and it doesn't really matter to us that we don't meet the FAA definition of a flying club because we don't have any interaction with the airport where that designation would benefit us.

If you're the kind of organization that has aircraft available for the use of your members however it probably makes sense to ensure that you're organized & run in such a way as to meet the FAA definition of a flying club.


What equipment is required to operate in Class "C" airspace?

A radio and a transponder.

As a pre-solo student, you really DO need to know this. If it is not familiar to you, I strongly recommend you read up on your airspace classes.


Do multi engines face the torque effect?

Maybe you mean the p-factor. If both engines are rotating clockwise, the plane yaws to the right. If one rotates clockwise, the other counter-clockwise, the effect cancelles out and the plane flys straight.


Do air-driven gyroscopic instruments suffer from icing or any blockage of filter?

From all that I have seen on that type of aircraft, there is merely a filter.  If one was operating in a dusty environment (eg the bush) then I would add those to a 100 hour check.  But honestly, I have never seen one clogged to the point it would not work.

They are not suspectable to icing as there is a low pressure drop across them, and they get their air from inside the cabin, where there is not a cold mist. It's usually rather dry and at low temperatures, it is probably heated.

The alternate air is for the static port, which is exterior, and will ice up, although it is a rather infrequent occurrence. The altimeter, airspeed and VSI are not gyro instruments, and are impacted by the static port. Keep in mind that if your altimeter is not reading correctly because of static port ice, then most likely your encoding altimeter is similarly off, and your mode C (or other) readout at ATC will be off. In my experience, the Cessna models you listed tend to ice less than the PA28 models, but again, it is rare, even for weather flyers. And if it is happening to you, you need to reexamine your weather choices.

While we are talking blockages, the pitot tube is the most frequent, and there have been times that I have had to remove a bug from the tube on the Cessnas. Let a mechanic do it the first time, so that you get some of the tricks. I usually use a straightened paper clip or a piece of safety wire, with a sharp hook, about 0.3mm bent in it. That will help you scoop out the bug.  Again, this doesn't happen often, as usually we have covers on pitot tubes, but I have had it happen in remote areas (like Central American hilltop unimproved airports) so if you are flying to those places you need to make friends with your mechanic so that you can manage the lots of different things that come up.

In summary, the vacuum gyros have a filter, and they don't tend to clog often. Some of them are rather coarse, but modern ones have 10 micron filters or better. If you are in an extremely dusty area, they should be periodically inspected. For most people, they will never have a problem with them.  (If you have that much dust in the cockpit, then you will have other problems, including avionics switches, dirt creeping into displays, etc.)


Why does Airbus not display the exact airspeed on the PFD?

Where it came from (history)
The Airbus-style airspeed tape on the A320 onwards comes from the A310 (Flight, 1987).

The present scale convention is similar to that used on the A310, and pilots have obviously readily adapted to it, but it does show that it may take a little time to shake off an old, ingrained response.

What the author is referring to is the speed-deviation indicator, an indicator like that on the 767 shown below that shows how fast/slow the plane is compared to the target speed.
(commons.wikimedia.org)
The A310 had this design when Thomson-CSF (later became Thales Group) took over the forward-facing crew cockpit (FFCC).

Thomson-CSF has been developing its A310 CRT symbology in close cooperation with Airbus and the customer airlines, and many details have changed since the company's selection as A310 supplier in September 1979 (Flight, 1980).

(Emphasis mine.)
Based on the above, Thomson-CSF reached the final design through usability engineering.
The A300 had a circular attitude indicator. The A310 change was to crop the sides to allow for an airspeed indicator.

The electronic attitude director indicator (EADI) which forms the basis of the PFD is no longer round, allowing more airspeed information to be presented on the sliding scale on the left.
(...)
The aircraft's indicated airspeed is shown by a yellow circle, the arrow through it indicating the speed trend. The airspeed symbol and trend remain stationary while the scale moves.

My opinion: This is the closest thing to the old "clockwork" cockpits, where an instrument's hand position was enough to glean the required information. Here the pilot would keep the yellow line (or circle on the A310) away from the too-slow and too-fast regions.
Not just Airbus
Below you can see the different versions on the 737 Classic, the one on the right featuring the "rolling digit cursor."

Something I found during my research I think is worth sharing about Airbus' philosophy that I haven't heard before:

The coach driver gives a command and the horses take care of the road, the A320 pilot makes a control input and the aircraft takes care of the flightpath (Flight, 1986).

I think the Airbus airspeed tape follows that, showing only what's relevant at a glance, as Radu094 wrote in their answer.


What did the controller say during my approach to land (audio clip)?

I think this is what the controller is saying:

  November Six Charlie Papa, cancel landing clearance. I'll have it back for you in a mile or so, traffic will be in position.

We can infer from this that the aircraft he's talking to (shortened callsign N6CP) has previously been cleared to land. But sometime since the controller decided to have another aircraft to line up and wait "in position" on the runway. The controller is now canceling that landing clearance, because he can't clear an aircraft to land while that aircraft is waiting for departure. And he's letting N6CP know that by the time they get 1 mile closer to the runway, he's anticipating that the waiting aircraft will get cleared for takeoff and N6CP will be cleared to land (again).


What are the regulations involved in aerial advertising?

The short answer is that you need to get an FAA waiver (special permission), as required by 14 CFR 91.311:

§91.311   Towing: Other than under §91.309.
No pilot of a civil
aircraft may tow anything with that aircraft (other than under
§91.309) except in accordance with the terms of a certificate of
waiver issued by the Administrator.

(91.309 is about towing gliders, so banner towing comes under 91.311.)
You need at least a private pilot certificate to tow banners - sport and recreational pilots aren't allowed to do it - but since most banner towing is paid work, in practice the pilot will usually have a commercial certificate (this is from the waiver instructions):

When banner tow operations are conducted for compensation or hire, the
pilot must have at least a limited commercial pilot certificate
(without an instrument rating) and at least a valid second class
medical certificate. An instrument rating is not a requirement for
this operation.

The FAA has a complete guide on banner towing and the waiver issue process has more administrative details. There don't seem to be many specific airspace requirements apart from the obvious, e.g. no towing in a TFR zone. But the FAA can impose more or less any conditions that they like as part of a waiver, and it will include the approved times and areas for operation.
(As an aside, it's widely believed in the pilot community that the permanent stadium and Disney TFRs are really there to prevent banner towing, not to increase security.)


Why is FL398 the REC MAX altitude on the A320?

I just came across the answer in the AFM it states

"THIS IS THE MAXIMUM ALTITUDE AT WHICH IT IS POSSIBLE TO MAINTAIN CABIN PRESSURE ALTITUDE BELOW 8000 FT"


What determines the "acceleration" and "thrust reduction" heights?

(Highlight mine.)

Short answer: airport briefing.

If no restrictions, then company SOP.

Thrust reduction is usually set to activate once the plane clears the noise abatement and/or MSA (Minimum Sector Altitude).

VNAV takes care of acceleration when activated as long as the SID is programmed. It also warns the crew if constraints will not be met.

Boeing 737NG VNAV. (Highlight mine.)

From Skybrary:

  Thrust Reduction and Acceleration Procedures

  On take-off, in order to position the aircraft to a safe height away from terrain and obstacles (i.e. a flight path of maximum height and minimum ground distance desired), the engine thrust is set to a high ‘take-off power’ setting (although this is not necessarily full power) and the aircraft attitude is pitched up to maintain a specific speed (usually in the region of V2 + 15kts). Once the ‘safe height’ is reached the engine thrust can therefore be reduced to a more appropriate (i.e. efficient) setting and the aircraft flight path can be changed to a more appropriate (i.e. efficient) flight path.

  In order to achieve that described above and also to provide minimum noise disturbance to the area surrounding the airport, regulatory procedures require aircraft to fly one of the two profiles given below during every departure. The aerodrome briefing pages will state which one of the two profiles is to be flown at each particular airport:

    At 1,500ft aal reduce thrust to climb power and accelerate the aircraft towards 250 knots, retracting flaps and slats.
    At 1,500ft aal reduce thrust to climb power maintaining V2 + 15kts. At 3,000ft accelerate the aircraft.

  Operator’s SOPs must therefore enable the above procedures to be flown.

Typical Boeing 737 climb profile:

Acceleration here would happen at (2) when VNAV is engaged. Default acceleration height depends on the airline, manual entry is possible from 400 to 9999 feet.

The default thrust reduction height is 1500 feet (lowest manual entry is 800).


What's it like to be a volunteer at the temporary airport set up at Burning Man?

I volunteered at the Airport in 2015 and it was a really cool experience.
I only worked one shift as "Night Watch" / "Border Control" which is basically making sure people going to/from the event to the parked airplanes have the proper wristbands and making sure no one tries to sneak in at night. There are a ton of other positions listed on the volunteer website you can read about here: http://airport.burningman.org/us-who-we-are-and-were/volunteer-info/

The volunteer jobs range from logistical stuff like processing passengers, to ramp operations like guiding taxiing traffic, checking arrival documents to actually running the UNICOM and giving weather advisories to local traffic, particularly about what runway/pattern is in use given the current winds.

Many of the positions (especially ramp side jobs) require some familiarity with how the airport operates and my impression was you "worked your way" up to those. Like many things at Burning Man, if you show up, volunteer and contribute you can end up doing some cool stuff.

You can subscribe to the volunteer mailing list by sending a blank email here:
airport-announce+subscribe@burningman.org

If you're curious about pilot experiences flying to/from the event (which is what I think your original question was about) I would subscribe to the aviators discussion list by sending a blank email to this address: aviators-list+subscribe@burningman.org

Both are great resources for getting first hand information about what its like to fly into and volunteer at 88NV


Is it normal to instruct an aircraft to squawk VFR if it goes around on an IFR visual approach?

No, that scenario does not sound normal to me. For one thing, a visual approach is an IFR procedure. Instructing the crew to change to a VFR squawk makes it sound like the controller is suddenly treating the flight as a VFR flight, which makes no sense. A controller is never allowed to just cancel IFR; going from IFR to VFR must always be explicitly requested by the crew ("cancelling my IFR flight"). We are not even allowed to suggest a flight to change to VFR, the idea has to come from the pilot.

Besides, it makes no sense that the controller would change the squawk code of a (presumably) already identified flight to a non-discreet code (1200/7000) since radar identification would then be lost and it would be impossibly to continue to provide radar service.

If the example you provide is a real one, there is obviously a reason for the controller doing what they did, however, based on the limited information you give here, it is hard to see what the reason would be. Maybe if we knew the whole picture, it would make more sense.


What is purpose of engine pylon airfoils on the Hondajet HA-420?

There is a pretty interesting write up on the pylon design here. According to that the shape was chosen for a number of reasons including flutter reduction, stall characteristics and wave drag reduction. There is also some more info here that briefly touches on the design.


What in-flight weather info is available to commercial pilots?

Air Traffic Control

Air Traffic Control (ATC) are often a major source of weather information for pilots. Modern ATC radars often overlay weather radar over the screen so ATC can assist pilots in avoiding weather. In terminal areas ATC may be equipped with additional systems such as terminal doppler weather radar (TDWR) or low-level windshear alert system (LLWAS). If able, ATC will impart any weather information they have to pilots to assist them in choosing the safest course. That's an ideal scenario of course and sometimes ATC isn't helpful.

En Route Flight Advisory Service (EFAS or Flight Watch)

  A service specifically designed to provide timely en route
  weather information upon pilot request is known as the en
  route flight advisory service (EFAS), or Flight Watch. EFAS
  provides a pilot with weather advisories tailored to the type
  of flight, route, and cruising altitude. EFAS can be one of
  the best sources for current weather information along the
  route of flight.

  A pilot can usually contact an EFAS specialist from 6 a.m. to 10
  p.m. anywhere in the conterminous United States and Puerto
  Rico. The common EFAS frequency, 122.0 MHz, is established
  for pilots of aircraft flying between 5,000 feet above ground
  level (AGL) and 17,500 feet mean sea level (MSL).

Hazardous Inflight Weather Advisory (HIWAS)

  Hazardous Inflight Weather Advisory (HIWAS) is a national
  program for broadcasting hazardous weather information
  continuously over selected navigation aids (NAVAIDs). The
  broadcasts include advisories such as AIRMETS, SIGMETS,
  convective SIGMETS, and urgent PIREPs. These broadcasts
  are only a summary of the information, and pilots should
  contact a FSS or EFAS for detailed information. NAVAIDs
  that have HIWAS capability are depicted on sectional charts
  with an “H” in the upper right corner of the identification
  box.

XM

Many modern avionics systems receive NEXRAD over XM as well as a myriad of other weather sources. Avionics suites such as the Garmin G1000 give pilots access to NEXRAD overlay over a map as well as a visual display of METARs, TAFs, FDs, PIREPs and many other weather information sources. There were a lot of acronyms there, but they can all be referenced in the two references provided at the bottom of this answer.

On-board Radar

Many aircraft are equipped with radar on-board. This provides a major step up from NEXRAD for making specific choices. Some pilots may disagree, but I view NEXRAD as a way to make "overview" choices about weather. NEXRAD is often too far delayed or affected by errors to make fine-grain choices. On-board radar can be directed at the airplane's altitude and provides an immediate picture of what's happening.

I also read the article from ForeFlight about the Airbus that got into hail. It's true that many general aviation aircraft have more in the cockpit that airliners. I'm not sure if airline pilots are allowed to use additional sources from things like ADS-B receivers they bring with them, but my guess is that while it's probably not forbidden, it's a risk to the pilot. If a situation arose where a pilot made a decision based on information from an unofficial source and it lead to a bad result it could be detrimental for the pilot and the airline. Most pilots probably stick to their official sources.

For pilots flying under the FAA, two good sources for the answer are the Pilot's Handbook of Aeronautical Knowledge (PHAK) Chapter 13 and AC 00-45G. Chapter 13 of the PHAK is dedicated to aviation weather services, many of chich are available in flight. AC 00-45G is dedicated to the same, it just tends to be updated a little more often and goes into greater detail.

Generally speaking though I have found that FAA materials haven't done the best job in keeping up with the fast pace of technology and its modernizing effects on avionics. Then again, the modern technologies are usually repackaging existing weather services and providing them in a better interface.


It seems this is a fairly new issue cropping up and I have been able to find some credible research on the topic (i.e. from official aviation authorities and not news outlets or lawyers websites...) but all of it is pretty recent. The CAA seems to be aware of the issue and has some information on it here. The two studies they link were published in 2017 so the topic seems to be recent, you can find the full text here and here.

The Australian authorities via CASA conducted a pretty hefty study on the topic in 2007 and came up with a list of 37 recommendations which includes the development of an anonymous online reporting system.

  That the Australian Government, through CASA and the ATSB, sponsor and
  fund the development of a single, central, internet-based,
  confidential reporting system on cabin air contamination incidents to
  be co-ordinated and operated jointly by CASA and the ATSB. To improve
  the reporting and monitoring of cabin air contamination incidents,
  this system should have web-based forms to facilitate the collection
  and collation of data from all authorities and companies responsible
  for cabin air contamination incidents that would enable the data to be
  tabulated into a de-identified and unalterable uniform document that
  could be accessed and utilized by all stakeholders.

They also are setting some resources aside for studying long and short term effects of an event

  That CASA in association with the Department of Health and Ageing
  (DOHA), the Institute of Health and Welfare or the NHMRC sponsor a
  project to define possible criteria for case definitions for short
  term and longer term health outcomes following episodes of cabin air
  contamination.

Clearly the CASA sees this as a real issue.

The FAA published a safety advisory on the topic in March 2018 and is clearly acknowledging the issue.

Its worth noting that most of these studies and claims refer to an "event" in other words a notable time when there was a fume event implying that this is not a constant occurrence. On the flip side, cabin air is actually pretty clean, as discussed here and researched here. Interestingly this CDC study seems to point to the slightly lower oxygen levels and more importantly tight quarters with a lot of other people to be factors in health issues on aircraft. They did this by comparing flight attendants with teachers who also work in lower circulation, high person density environments.


How far should the two propellers on a twin engine plane be apart?

I'm assuming that you want to minimize efficiency losses due to propellers competing for clean air. I do no know what the optimal distance is but looking at a few practical examples it seems that as long as the propeller disks aren't overlapping you should be alright.

Here is a B 29 superfortress front view you can see the propeller disks are tangential to each other. The B 17 has a similar set up.

Here is a Tupolov bear as a more modern example there is more space between the propeller disks here than on the b 29. I would say this is probably because of the significant difference in horse power between the bears engines and a b 29's.

I hope this helps shed some light on what you were looking for. If you need more information your best bet is to look for a NACA paper on the topic. If there is research on this (and published in english) they are likely to be the ones who have done some.


Who manages air traffic during Red Bull air races?

This is a fairly broad question since the races move around the world the the regulations vary heavily depending on where its occurring but ill answer for the FAA understanding that most countries treat this kind of stuff similarly. The Air race its self has its own control tower of sorts that talks directly to the pilots to clear them onto and off of the course (this seems to be #2 in your question) but local ATC will be involved for departures.

Depending on where they intend on flying they may need to get a special flight permit, these are applied for in advance with the FSDO. I dont know if this is something the teams need to do or if this is something organizers handle. If the country has such regulations a TFR may be issued, for example this one from the french race (thanks to @mins for digging it up!). This keeps traffic out of the way so the organizers don't to worry about a Cessna 150 putting through the course @90Kts trying to "watch the race".

The planes typically depart from a local field close to the course. Here in the US they need to follow the same procedures as anyone else, if its controlled that means ground and tower coms if its uncontrolled thats CTAF announcements.

Once in the air they will head to the race course. Since these planes are effectively VFR radio com's is not mandatory outside of controlled airspace. The tower may simply transition them outside of the terminal area to the course frequency when appropriate.

According to this walk through the aircraft has one radio for taking to "race control" who clear them through the course. This behind the scenes video will walk you through how race control works and what they do.

No communication occurs during the race its self, you can see in this video the pilot is mostly concentrating on breathing and flying.

Once off the course they will either loiter around if they need to run again or head back to the airport, heading back is the same as any flight, fly on over and call up the tower to request landing.

This podcast is also a pretty great overview on the race and what it takes to be a pilot.


Would all these three things have the exact same effect on the flight duration of a glider?

Scenarios 2 and 3 would be almost exactly the same. Scenario 1 would be very different. However, the glider would be able to stay up for almost exactly the same amount of time in all three scenarios.

The basic summary of what would happen: In scenario 1, both the weight and the mass would be doubled. In scenarios 2 and 3, the weight would be doubled but the mass would remain the same.

The simplest way to distinguish scenario 1 from the others is to pitch into a vertical climb (or a vertical dive). In scenario 1, the glider will accelerate downwards at $1\ g$, but in scenarios 2 and 3, it'll accelerate downwards at $2\ g$.

Scenarios 2 and 3, on the other hand, are almost completely identical. Specifically:

Scenario 2 simply adds more gravity. Pretty straightforward.

Scenario 3 consists of having the ground accelerate "up" at $1\ g$. We can look at this scenario in a frame of reference where the ground remains stationary. In this frame of reference, everything is just like the real world, except that everything is now experiencing an inertial force equal to $1\ g$ straight down.

How does an inertial force work? Inertial forces feel just like gravity. In fact, the only differences between the extra forces in the two scenarios are:

In scenario 2, the direction of the extra force changes as you move horizontally, because the direction of "down" changes as you move. In scenario 3, the extra force is in the same direction everywhere: namely, the direction opposite the direction of acceleration.
In scenario 2, the extra force gets weaker as you get farther away from the earth. In scenario 3, the extra force is equally strong everywhere.

Both of these differences are probably too small to measure.

Now, finally, I said that the glider will be able to stay up for the same amount of time in all three scenarios. This is because, although the mass of the glider differs between the three scenarios, its weight is the same in all three scenarios. And if the glider is flying at a constant speed in a straight line, weight is the only quantity that matters; mass is now irrelevant, because the glider is not accelerating (in the frame of reference where the earth is stationary).


Are there competitors to Jeppesen making Electronic Flight Folders?

For the UK NATS makes most of the charts which I frequently use for flight stimulation. I believe that for charts especially the Aerodrome charts are much better than the style of charts Jeppesen produce. The only downside is that the charts aren't compiled in the way that charts on Jeppesen are and must be compiled. But for outside the UK the best charts in my opinion are Jeppesen.


The reason radios in general are used is covered in this question Why is radio communication still used?

As for why VHF is the band of choice its largely because its assigned for aviation use and the the radio spectrum is not unlimited. Here in the US the FCC regulates which bands are for what, you can find the full list here and you will see that many of them are in use for lots of different things so using a higher (or lower) band for aviation may not be possible as they are likely used for something else.


Do I need a trim tab system on my twin tail?

Yes a trim system would be a most excellent idea. If you can trim the aircraft such that it just flies straight on when you release your hands and feet off of the flying controls, the flight will be more enjoyable than when you need to keep pulling one way for the duration of the flight, like walking while holding up a briefcase in front of you.

Trim adjusts the neutral point of the flying controls: the point where the stick returns to when released.


As previously seen in a comment section, there are two main schools of thought:

The dimensionality indicates the actuation Degree of Freedom (1D has
1 DoF per exhaust vector, 2D has 2).
The dimensionality indicates the aircraft attitudes that can be affected (2 exhaust vectors with 1 DoF each can affect pitch and roll, hence this would be a 2D thrust vectoring, 2 exhausts with 2 DoFs can affect all 3 attitude angles, hence 3D)

Using the definitions of these two approaches, to make a couple of examples, the F22 thrust vectoring is 1D for the first group and 2D for the second, while the Su30 is 2D and 3D respectively.


What is the relation between aircraft descent rate and speed?

If the pilot commands a certain glide path angle, any change in airspeed will also change vertical speed, because both are connected by the glide path angle $\gamma$.

Note that the vertical speed is air speed$\cdot\sin\gamma$. Climbing or descending makes no difference; only the sign of $\gamma$ changes (positive $\gamma$ means the aircraft climbs). Also the type of propulsion will not affect this basic relationship.

Since descending reduces potential energy, some other energy will increase. If the aircraft speeds up, its kinetic energy increases until the increase in drag balances the energy gain. Reducing engine thrust or deploying spoilers will limit the speed increase, but for a steep descent, even with idling engines and full spoiler deflection the flight speed will increase.

  Is it the same for aircraft climb rate?

No. In a climb the potential energy must be increased, and the primary source of energy are the engines. Only now will the type of propulsion affect the result: Both the speeds for the steepest and the fastest climb for propeller aircraft are fairly low, so an increase in vertical speed will normally be accompanied by a reduction in flight speed, freeing up more excess energy for climbing.

Jets also need to fly slow for their steepest climb, but need to pick up speed for their fastest climb speed. This is the more pronounced the lower the bypass ratio of the engines is, so fighter jets need speed to climb quickly. Turbofan-powered airliners fall between propeller aircraft and fighter jets and prefer a moderate speed for their best climb performance.

This is all only true in stationary flight. In a pull-up, any aircraft can gain altitude quickly by trading kinetic for potential energy. But this is a transitionary effect - the high climb speed will only last while the aircraft has excess speed to spend.


What happens during a solo checkride and how do I put myself in the best position to be successful?

It's pretty simple.  You will be asked to demonstrate everything you've learned.  The Grade II is evaluating you and is also evaluating your instructor's teaching skills.  The two hour block probably includes extra time allowance if the check instructor wants to give you remedial or supplemental training before signing you off (assuming you are acceptable), and the actual flight may be the full 2 hours or quite a lot less.

Just relax and do what you're told to the best of your ability and don't worry about it. To best prepare, go through all the things that you may have to recall from memory, especially emergency memory items or sequences or mental check lists, and drill drill drill that stuff on the ground while at home or while driving until you can't stand it any more, then do it some more.  You want to be able to spit out procedures or numbers automatically without thinking, under pressure, with distractions, and to do that it just takes repetition (have a friend shove you and yell at you while you recite everything - you'll know right away if you have things internalized sufficiently).

I cannot stress that aspect enough.  If you have everything that needs to be memorized fully burned in to your brain beforehand, it will massively reduce the stress of the flight itself and you'll find you are better able to free your brain to concentrate on flying and it's only a matter of having the physical and judgement skills in place or not.

The other thing to add is that instructors and examiners love students who show up well prepared, who have obviously taken a lot of time and effort to learn what they need to learn, who can spit out answers to verbal questions immediately without having to mull the question over (to a reasonable degree).  The result is that they will tend to cut you a bit of slack on little screw ups you make during the evaluation or test if it's obvious you are putting in the work, and obviously, aren't dangerous.  In the end they just need to be satisfied you won't kill yourself, and a lot of that comes from a general feeling of comfort the examiner gets from the overall experience of flying with you and knowing what you have put into it.


Why are non-essential passenger flights still being flown?

As discussed in this question airplanes carry a lot more than just passengers so shutting down passenger flights can stop the flow of essential supplies as well as people. In some cases charter flights are being used during this crisis but the general movement of people (even essential people) often relies on commercial flights.

Similarly most states are issuing-shelter-in-place and stay-home-orders while it is only the federal government via the FAA that can totally shut down the airspace. Individual states, municipalities and private owners can shut down airports that they control but this may only stop flights in and out of those airports.

Its worth noting that airports in other countries are starting to shut down. It is more than likely flights will be seriously curbed as a result.


Once you have passed the oral portion of a checkride, do you have to retake it ever again?

Unfortunately, yes.  It is part of the checkride and if you don't finish it within the required time you will need to take the entire checkride again.

The commercial PTS shows the areas of operations that are included in the checkride, and the oral itself is given throughout the entire process.  What most people consider "the oral" is the examiner asking questions during the "preflight preparation" portion of the checkride.  This is where they ask the most questions because in all reality, this is where you as a pilot should be asking the most questions.

There is a note in the beginning of the PTS which talks about this:

  Examiner Responsibility

  The examiner conducting the practical test is responsible for
  determining that the applicant meets the acceptable standards of
  knowledge and skill of each Task within the appropriate practical
  test standard. Since there is no formal division between the “oral”
  and “skill” portions of the practical test, this becomes an ongoing
  process throughout the test. Oral questioning, to determine the
  applicant’s knowledge of Tasks and related safety factors, should be
  used judiciously at all times, especially during the flight portion of
  the  practical test. Examiners shall test to the greatest extent
  practicable  the applicant’s correlative abilities rather than mere
  rote  enumeration of facts throughout the practical test.

  ...

As a small aside, you don't really get two months, but rather 60 days.  This is covered in 14 CFR 61.43:

  §61.43 Practical tests: General procedures.

  ...

  (f) If a practical test is discontinued, the applicant is entitled
  credit for those areas of operation that were passed, but only if the
  applicant:

  (1) Passes the remainder of the practical test within the 60-day
  period after the date the practical test was discontinued;

  (2) Presents to the examiner for the retest the original notice of
  disapproval form or the letter of discontinuance form, as appropriate;

  (3) Satisfactorily accomplishes any additional training needed and
  obtains the appropriate instructor endorsements, if additional
  training is required; and

  (4) Presents to the examiner for the retest a properly completed and
  signed application.


What components of the Boeing 787 are made out of titanium?

The Boeing 787 is special due to its high count of composite parts. When aluminium comes in contact with graphite fiber, contact corrosion will damage the aluminium whereas titanium will be unaffected due to its higher position in the electrochemical series.

15% of the initial 787s empty weight consists of titanium, a fraction much higher than in other airliners and one of the reasons that Boeing lost 23 million USD on each of their 787s sold initially.

787 material breakdown (picture source). Dark grey is carbon fiber composites and light grey is glassfiber composites.

The linked Reuters article contains a few parts which Boeing made from titanium in the first 787s:

  Boeing has changed the cockpit window frame to aluminum from titanium, and has changed the frames of some doors to composite from titanium. Special coatings or materials are used to prevent aluminum corrosion, experts said. It wasn’t known how much Boeing saved by the change. Boeing declined to comment.

The article goes on to mention a part in the wing-fuselage connection which is milled from a solid block of titanium. 97.5% of the block is lost when it is machined - very similar to the Tornado center wing box!

Another use of titanium is in the hi-lok fasteners which are used to bolt metallic or graphite parts together. I would expect that those are the biggest use of titanium in regular aluminium airliners, because using titanium hi-loks instead of steel results in weight savings.


What are the practical impacts of airports in the US being mostly IATA Level 2?

Why aren't there many level 3's in the US?

Let's check the IATA criteria:

  A Level 3 airport is one where:

  a) Demand for airport infrastructure significantly exceeds the airport’s capacity
  during the relevant period;

  b) Expansion of airport infrastructure to meet demand is not possible in the
  short term;

  c) Attempts to resolve the problem through voluntary schedule adjustments
  have failed or are ineffective; and

  d) As a result, a process of slot allocation is required whereby it is necessary
  for all airlines and other aircraft operators to have a slot allocated by a
  coordinator in order to arrive or depart at the airport during the periods when
  slot allocation occurs.

a) Demand exceeding capacity

According to this study, the demand levels on US airports is lower compared to the EU.

  In 2014 the average payload at 11 of the largest US airports was 108 passengers per
  aircraft. At 10 of the largest EU airports, the average was 134 passengers per aircraft.
  This confirms that the structure of traffic is quite different.

b) Infrastructure and expansion

In the US, say apart from New York, expansion is easy. A good comparison would be comparing a major European city with a major US city. The US had the benefit of hindsight when they planned for their cities. Heathrow has been trying to expand since forever, and only recently a third runway was approved.

According to this MIT presentation, for the top 34 airports, the US has 4.12 runways per airport, compared to 2.47 in Europe.

How do airlines manage?

Since a) and b) are usually not met, c) and d) are less likely to happen.

c) and d) Schedule adjustments and slot allocation

14 CFR Part 93. The FAA stepped in a long time ago, and hasn't changed a thing since the deregulation act. All the majors who had all the slots, are hanging on to them.

Any trading that happens is not through an open auction. Only once was an experimental free-market auction held in 1982. So any problem, is evidently usually solved voluntarily.

According to the same MIT presentation, when slots exist in the US, they are "set with reference to VMC capacities". While Europe uses IFR procedures figures. This allows the US to declare higher capacities than Europe. So, it's easier for airlines to schedule flights in the US.

How does it impact the pilots (flights)?

Again, from the MIT presentation, the US faces high delays when IMC (instrument meteorological conditions) sets in, because of using VMC (visual meteorological conditions) capacities. Europe is more reliable in this area. So a pilot flying into a level 2 airport in bad weather in the US is likey to be delayed, whether in the air or on ground.

  Schedule reliability is much lower in the US than in Europe
  Reliability of schedules in US declines over the course of a day, particularly in the presence of poor weather
  In defense, US airlines have been increasing (up to 2007) the advertised flight durations; European airlines have not
  European airports place a premium on predictability and "smoothing" operations, relying on (often too low) declared capacities and IFR separations at all times

They also mention delays are not necessarily due to over capacity. My interpretation: You can have a time like Christmas with many flyers and bad winter weather causing many delays and cancelled flights. But still, airlines can't apply the level 3 options. Especially that they can't resort to c) and d) to move Christmas time to the summer.

All airlines suffer, the passengers expect it, and that's it. However, there are studies for and against changing the way the US handles capacities and slots (messy debates).

So, there are two systems, with no clear winner.


What is a "sidestep landing" in an instrument approach?

From the AIM 5-4-19:

  5−4−19. Side−step Maneuver

  a. ATC may authorize a standard instrument approach procedure which serves either one of parallel runways that are separated by
  1,200 feet or less followed by a straight−in landing on the adjacent
  runway.

  b. Aircraft that will execute a side−step maneuver will be
  cleared for a specified approach procedure and landing on the adjacent
  parallel runway. Example, “cleared ILS runway 7 left approach,
  side−step to runway 7 right.” Pilots are expected to commence the
  side−step maneuver as soon as possible after the runway or runway
  environment is in sight. Compliance with minimum altitudes associated
  with stepdown fixes is expected even after the side−step maneuver is
  initiated.

  NOTE−
  Side−step minima are flown to a Minimum Descent
  Altitude (MDA) regardless of the approach authorized.

  c. Landing
  minimums to the adjacent runway will be based on nonprecision criteria
  and therefore higher than the precision minimums to the primary
  runway, but will normally be lower than the published circling
  minimums.


What is needed to remove my CPL restriction after becoming a US citizen?

You will need to pass the US commercial pilot test to remove the restriction.  If you have enough hours, you may want to consider applying for an ATP certificate.

A couple of things are required to be completed.

Verify the authenticity of your foreign license through the FAA
https://www.faa.gov/licenses_certificates/airmen_certification/foreign_license_verification/
Complete an application for the new commercial or ATP license
Pass the appropriate practical test


Did Biplane pilots turn off their engines before landing?

Sometimes--

Rotary engines had rather primitive throttle arrangements, so a pilot would often use a "coup" button or "blip" switch, mounted on the control stick, to "blip" the ignition on and off and give partial power.

However, an alternative technique was recommended for some rotary engines:

  By 1918 a Clerget handbook advised maintaining all necessary control
  by using the fuel and air controls, and starting and stopping the
  engine by turning the fuel on and off. The recommended landing
  procedure involved shutting off the fuel using the fuel lever, while
  leaving the blip switch on. The windmilling propeller made the engine
  continue to spin without delivering any power as the aircraft
  descended. It was important to leave the ignition on to allow the
  spark plugs to continue to spark and keep them from oiling up, so that
  the engine could (if all went well) be restarted simply by re-opening
  the fuel valve. Pilots were advised to not use an ignition cut out
  switch, as it would eventually damage the engine.[7]

  Pilots of surviving or reproduction aircraft fitted with rotary
  engines still find that the blip switch is useful while landing, as it
  provides a more reliable, quicker way to initiate power if needed,
  rather than risk a sudden engine stall, or the failure of a
  windmilling engine to restart at the worst possible moment.

(Source: https://en.wikipedia.org/wiki/Rotary_engine#Monosoupape_rotaries, quoting Nahum, Andrew (1999). The Rotary Aero Engine. NMSI Trading Ltd. pp. 44–45. ISBN 1-900747-12-X.)

The key here is "rotary", not "radial", and regardless of which technique was used, the concern wasn't to avoid a hazard from engine torque or other related effects per se, but just to control the power output of the engine to allow the aircraft to descend for landing.

Of course, at other times, such as when taking off, the gyroscopic reaction to the whirling mass of the engine was a very significant factor while flying with a rotary engine, and the low ground clearance of the lower wingtips of most biplanes wouldn't have helped matters.

You can read much more here--

How are rotary engines controlled?

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

http://www.theaerodrome.com/forum/showthread.php?t=17121

http://www.theaerodrome.com/forum/showthread.php?t=2302&page=1&pp=10


The aileron itself doesn't stall, being part of the main wing.  But since it alters the camber of the main wing it changes the local angle of attack in effect.  On older airplanes, a down aileron at low speed could trigger a stall separation of the wing in the area of the aileron and if you applied aileron to correct a wing drop at the stall, it would just speed things along and over you go.  This was one of the reasons for slots in front of the ailerons on airplanes like the Globe Swift.

Not sure how it is taught today (I learned to fly in 1975) but long ago pilots were always taught to avoid aileron input close to the stall and keep wings level with rudder, although on modern airplanes with washout and other features to delay stall near the tip you can generally get away with it.


Why can't some airports handle heavy aircraft while others do it easily (same runway length)?

There are a few possible reasons Bournemouth (EGHH) can support a Boeing 787 but Kherson (UKOH) can't. Runway length is definitely not the issue. The runway at EGHH is 2271 metres long, the one at UKOH is 2500 metres long.

The runway at UKOH is slightly narrower, though: 42 metres compared to 46 metres at EGHH. Whether this has operational significance, I do not know.

Another thing to compare is the strength of the pavement, which is expressed as a Pavement Classification Number, or PCN.

The PCN of the runway at EGHH is 46/F/B/X/U, at UKOH it is 28/R/C/X/T. Those values can be decoded like this:

EGHH: Load carrying capacity: 46, flexible pavement (typically asphalt), high strength, high tire pressure supported.
UKOH: Load carrying capacity 28, rigid pavement (typically concrete), low strength, high tire pressure supported.

This is a bit technical, but what it means, in essence, is that the pavement at UKOH is not nearly as strong as that at EGHH. The 787 has a max takeoff mass of around 230 tons, so it needs some pretty strong pavement to support it.

Finally, the rescue and fire fighting services provided at the two airports is different. EGHH provides up to CAT 9 (capable of handling aircraft up to 76 metres long and 7 metres wide (fuselage width)). UKOH provides only CAT 7 (capable of handling aircraft up to 49 metres long and 5 metres wide.

The 787-8 (the smallest of the 787 variants) is 56,7 metres long and 5,77 metres wide. So most likely, what's keeping Kherson Airport from handling 787's is a big investment in new pavement, and maybe the need to buy a few extra fire trucks.

Then of course, there's also the whole question about capacity of the terminal building, size of gates and various equipment (push back trucks, stairs, jet bridges etc.). Those things are a bit harder to compare directly, though.


Why does the B-2 Spirit have a pattern of thin white lines?

@RAC and @Hobbes are right. I found a high res photo on defense.gov.

The crop below shows WALKWAY and NO STEP instructions indeed. Similar to what you'd find on a jetliner's wing.

It makes me wonder though why the person below did not abide.

Source: https://tucson.com/news/national/costly-b--bombers-both-tech-marvels-hangar-queens/article_273b0f50-71f6-56ca-a399-401e342658c1.html


Can a supersonic plane use a subsonic wing if the nosecone shock produces subsonic airflow around the wing?

Normally, the flow speed at the wing is about the same as the speed ahead of the bow shock. Only if the fuselage is still conical and expanding at the wing station would the local flow speed be smaller. In order to be subsonic, you would need an absurdly blunt fuselage at Mach 1.5. But the wing is in a way still subsonic if its leading edge sweep is sufficient.

If you look closely enough, every shock has a subsonic region, but it is normally very small. The size of the subsonic region depends on the flow speed and the bluntness of the body causing the shock. See the diagram below for the parts of a classical oblique shock.

Diagram of an oblique shock and its three areas (picture source)

Supersonic aircraft are pointed at the front end in order to minimize the region of the strong shock, resulting effectively in an attached shock. The steeper the shock angle for a given flow speed, the higher the losses are. Only in hypersonic vehicles are blunt noses used on purpose, but nor for braking but for limiting local heat loads.

Why does the subsonic region disappear so soon? Because the cross section of the body stops to grow in flow direction, and the pressure energy past the strong shock is converted into speed again in expansion waves.

This means that the wings still fly in supersonic flow. If the fuselage has a constant cross section along the wing's chord, the flow speed is even the same as the speed ahead of the shock. Otherwise, the tail shock would have a smaller cone angle, which it does not have; the flow accelerates again in expansion waves when the conical nose changes to the regular fuselage, and again when the fuselage contracts at its end.

Now it makes sense to sweep the wing such that it will fit inside the Mach cone resulting from the inboard wing section. This results in a subsonic orthogonal speed component at the leading edge. The important insight here is that the spanwise speed component of the flow is not affected by the wing, and only the orthogonal component counts. If that component is subsonic, the whole wing behaves like a straight wing in subsonic flow. Note that all supersonic aircraft with a subsonic leading edge use blunt-nosed airfoils, because those create a suction force (PDF!) which reduces drag.

At higher speed sweep needs to be so steep that the problems of swept wings cannot be tolerated any more. Then and only then it makes sense to have a supersonic leading edge which has less sweep than the Mach cone and needs to be sharp in order to minimize drag. Another way to combine high sweep and good subsonic characteristics is to use variable sweep. This was the preferred solution until it was realised that high supersonic speed is rarely used in combat.


Why did a circular paper aeroplane of larger diameter fly further than one of a smaller diameter?

The larger glider flies with a larger Reynolds number, so friction drag will be lower relative to lift.

Using paper of the same grammage (weight per area) would result in the same wing loading and the same flight speed, and the Reynolds number will grow linearly with glider size. If you look up in the linked answer how friction drag changes with Reynolds number, you will see that friction drag drops with increasing Reynolds numbers.


You are very correct that this can happen- If i'm not wrong, what happened during the last 6 minutes of Swissair Flight 111 will never be known for this reason.

In general however, by the time the fire would spread to this extent the CVR and/or FDR would probably have picked up some hint of fire and the reason. To increase survivability, the FDR and CVR are connected off separate power buses ('boards'), so I'd imagine the cables for each not exactly next to each other on the fuselage, and if one trips, the other one will hopefully still run for a bit longer.

The cockpit voice recorder operates a simple microphone I believe, so I'd expect that it wouldn't be much more complicated than your computer microphone. The data would probably be converted from analog to digital before being transmitted backwards.

As for the 88 parameters that the Flight Data recorder currently requires, I'd imagine that there would be a serial connection from each relevant part- each flight computer, engine etc. all leading to the back of the aircraft.

Source: FDR Handbook- NTSB


When cleared for an approach and not on vectors, is a depicted course reversal always required?

Yes, with this procedure you are required to fly the procedure turn unless you are flying the CVV transition (which is notated as NoPT), are receiving vectors to final, or receive a clearance for a "straight-in approach" over EYWOK.  If you are cleared direct to the final approach fix, none of these apply (but remember that you can always request a straight-in approach if you don't want to do the course reversal)!

FAR 91.175

  (j) Limitation on procedure turns. In the case of a radar vector to a
  final approach course or fix, a timed approach from a holding fix, or
  an approach for which the procedure specifies "No PT," no pilot may
  make a procedure turn unless cleared to do so by ATC.

The AIM states:

  5-4-6. Approach Clearance

  4. If proceeding to an IAF with a published course reversal (procedure turn or holdinlieu of PT pattern), except when cleared for a
  straight in approach by ATC, the pilot must execute the procedure
  turn/holdinlieu of PT, and complete the approach.

  5. If cleared to an IAF/IF via a NoPT route, or no procedure turn/holdinlieu of PT is published, continue with the published
  approach.

  6. In addition to the above, RNAV aircraft may be issued a clearance direct to the IAF/IF at intercept angles not greater than 90 degrees
  for both conventional and RNAV instrument approaches. Controllers may
  issue a heading or a course direct to a fix between the IF and FAF at
  intercept angles not greater than 30 degrees for both conventional and
  RNAV instrument approaches. In all cases, controllers will assign
  altitudes that ensure obstacle clearance and will permit a normal
  descent to the FAF. When clearing aircraft direct to the IF, ATC will
  radar monitor the aircraft until the IF and will advise the pilot to
  expect clearance direct to the IF at least 5 miles from the fix. ATC
  must issue a straightin approach clearance when clearing an aircraft
  direct to an IAF/IF with a procedure turn or hold-in-lieu of a
  procedure turn, and ATC does not want the aircraft to execute the
  course reversal.

  7. RNAV aircraft may be issued a clearance direct to the FAF that is also charted as an IAF, in which case the pilot is expected to execute
  the depicted procedure turn or holdinlieu of procedure turn.  ATC
  will not issue a straightin approach clearance.  If the pilot desires
  a straightin approach, they must request vectors to the final
  approach course outside of the FAF or fly a published “NoPT” route.
  When visual approaches are in use, ATC may clear an aircraft direct to
  the FAF.


Why are there many different approach lighting systems?

The different systems generally have to do with ILS landings and the ability to have the runway in sight. As approach systems have gotten better and our understanding of flight mechanics and general operations has increased the need for different systems has evolved. As new requirements come out and new (generally lower) minimums are allowed different lighting requirements may accompany that but not all airports can always afford to install new lighting (and other related things) as such most regulations allow older systems to stay in place so long as the minimums remain.

In some cases airports simply don't have the physical land at the runway threshold to install larger/longer light systems. In some cases they need to do things like extend out into the ocean to install the lights.


Why is YF22 designed with conventional rudders while YF23 with all-moving rudders?

As a general rule when you see an all-moving surface vs a fixed fin and control surface it's because you get more control authority per unit of surface area, so the surface itself can be smaller.  Better stealth, less drag.  You lose the passive weathervaning effect that provides basic yaw stability you get with a fixed fin, but with a fully active artificial stability system, that might be acceptable to the designer (although maybe not to the Air Force).

The 23 went with what amounts to a V tail, on top of all-moving surfaces, with the surfaces providing yaw and pitch authority at same time, and a fully active artificial stability system to make up for the lack of fixed surfaces.  This would have had much less drag than the regular horizontal and vertical surfaces, and probably a better radar signature to boot.

Why it lost out to the 22? According to Wikipedia, it was faster and had better stealth, as your would expect from the tail arrangement, but was less agile, so we know what the Air Force's priorities were. And there was probably a range of other factors that made the 22 a better choice overall (it could be that the 23 was just a bit too radical, which may have impacted maintainability, reliability, and cost factors in a way that made the 22 look like a safer bet).


There is a notation for V15 (low altitude IFR airway) in the southern portion of the top map in your question.

V15 is a Federal Airway, normally used for IFR operations and shown on IFR charts as well as VFR Sectionals. Federal Airways, unless otherwise notated, begin at 1200 AGL. These airways are Class E airspace. If you look in the legend of your Sectional Chart it describes this airspace.


This approach of using an engine is called pulse and glide. It generally works because each engine has an optimal power setting at which it converts fuel into power most efficiently.
If the most efficient power is higher than is required, something should be done to accumulate and later use the excess energy. Raising the vehicle up looks like a solution, better than accelerating.
This method can only work if the power to efficiency curve of the machine is known. Otherwise, it is easy to do worse.


How to understand US military aircraft designation on the vertical stabilizer?

The number on the vertical tail is the aircraft serial number, not the type designation. Here the serial number is AF 41 823. The '4' is the last digit of the finacial year in which money was allocated to manufacture the aircraft and the remaining 4 digits represent the sequence number indicating the sequential order in which the particular aircraft was ordered within that particular financial year.

From USAF serials:

  Starting on July 1, 1921 (the beginning of FY 1922) a new serial number system was adopted based on procurement within each Fiscal Year. Each serial number now consisted of a base number corresponding to the last two digits of the FY in which money was allocated to manufacture the aircraft, and a sequence number indicating the sequential order in which the particular aircraft was ordered within that particular FY. For example, airplane 22-1 was the first aircraft ordered in FY 1922, 23-1 was the first example ordered in FY 1923, etc. This system is still in use today.

Apparently, USAF decided to have five digits in its tail number in 1958. This resulted in the cutting of first digit of the financial year.

  Camouflage began to reappear on USAF aircraft during the Vietnam War, and this led to a change in tail number presentation. The letters "AF" were added directly above the last two digits of the fiscal year, followed by the last three digits of the sequence number. The three-digit sequence number has a height of the AF and fiscal year letters combined and is sometimes called the "large" component of the tail number. For example, F-4E serial number 67-0288 had the tail number 67(small) 288 (large). This could of course lead to confusion, since aircraft 67-1288, 67-2288, etc would have exactly the same tail numbers as 67-0288 under this scheme. This would not ordinary cause a whole lot of difficulty unless of course some of these larger serial numbers also happened to be F-4Es (which they were not). Unfortunately, the system was not always consistent--for example F-4D serial number 66-0234 had a tail number that looks like this: 60(small) 234(large).

So, '4' represents the second digit of the finacial year, and 1823 gives the sequential number. The aircraft appears to be a F-100 Super Sabre. From f-100.org, the actual serial number appears to be 54-1862, a F-100C-20-NA model.


How do I use the GNS 620 Trainer provided by Garmin?

I found all the information needed in the "Trainer's User Guide.pdf" that was installed with the software.

In short, launch ONLY the GTN - G600 Trainer.  Do not have any other components started.

3 windows should launch: GTN Trainer, G600 Trainer and Navigation Control.

Give it a good 30 seconds to load up, then on the GTN Trainer window, click "Power On".
All windows should come up and be active.


How does one reverse direction on a VOR radial?

Spin the obs 180 so it changes from "To" to "from" then make a 210-220 degree turn(180 plus a 30-40deg intercept) and fly until the VOR radial comes in, then track the VOR.


How is the glide ratio affected when converting a wheeled plane to floats?

As glide ratio is the same as the L/D ratio, the increase in drag due to the addition of floats will reduce it. The Beaver's POH gives the effect of addition of floats in the glide ratio:

DHC-2 Beaver's Glide ratio; image from DHC-2- Beaver POH

Note that at their configuration for best glide ratio, there is a drop in about 10% in glide ratio for the configuration for floats. This will differ for different configurations and operating conditions, but the basic effect of addition of floats will be a reduction in glide ratio.


Is the airspace at KGPT class E or G when the tower is closed?

To expand a little more on what @rbp said, the VFR Sectional Note is referring to the Class D and Class E (sfc) designations.  So, when referring the the Chart Supplement, which says AIRSPACE: CLASS D svc (1200-0500Z) other times CLASS G they are referring to the Class D and Class E (sfc) specifically—just as @rbp said.

Now consider what the next level of controlled airspace is when the tower is closed and the airspace over KGPT becomes Class G. It would be 700’ AGL Class E airspace. The AIM goes on to detail this (emphasis mine):

  Where a Class D surface area is part-time, the airspace may revert to either a Class E surface area (see paragraph 3−2−6e1) or Class G airspace. When a part–time Class D surface area changes to Class G, the surface area becomes Class G airspace up to, but not including, the overlying controlled airspace.

Source: Aeronautical Information Manual (AIM), Change 1, May 26 2016, 3-2-5 Class D Airspace (13 MB PDF)

And goes on to explain in Note 2 of paragraph 3-2-5 (with added emphasis):

  Normally, the overlying controlled airspace is the Class E transition area airspace that begins at either 700 feet AGL (charted as magenta vignette) or 1200 feet AGL (charted as blue vignette). This may be determined by consulting the applicable VFR Sectional or Terminal Area Charts.


Do thermals stop rising when clouds are formed?

No, the opposite is in fact true. When the water condenses, it releases latent thermal energy, causing the air to rise even faster. That is why some glider pilots (who are appropriately licensed) fly, not just under, but into cumulus clouds to gain height.

When water vaporizes, it absorbs thermal energy. That is why, for example, humans sweat to cool down. As the sweat vaporizes, it removes thermal energy (heat) from the body. This thermal energy is stored in the water vapor, and will be released when it condenses.

The air in a thermal will only stop rising once it reaches the temperature of  the surrounding air, which can happen at different altitudes, depending on the state of the atmosphere. The main reason rising air cools down is because there is a relation between temperature and pressure. As the air rises higher, the pressure drops, and the temperature does the same. This can be depicted on a diagram of the temperature gradient, like this:

The thick red line is the ambient temperature of air at different levels. The oblique lines indicate the rate at which a column of rising air will cool down as it rises. As long as the thick red line is more inclined than the oblique lines, it is an indication that air will continue to rise, since it will not cool down fast enough to reach the temperature of the surrounding air.


How can I find the maximum climb angle of a propeller driven aircraft from a graph of vertical velocity against airspeed?

All you need to do is to plot vertical versus horizontal speed using the same scale on both axes. Then the solution is the point with the steepest angle from the origin of the graph.
Of course, it helps to do this in metric units. And to add a description to the axes of a plot. The solution can then be directly read from the graph.


Why are turbofan inlets circular- or oval-shaped instead of square-shaped?

Airliner jet intakes are round because the engines are round, and for subsonic flight that's all you need - it's easy and cheap to engineer, provides a clean airflow for the engine and unlike some other shape doesn't present unnecessary frontal area that will only cause drag. You've already identified ground clearance as the reason for a flattened shape on some installations.

Ah, you say, what about Concorde or the Tu144?

Source: http://www.hitechweb.genezis.eu

Notice that I specified 'subsonic'. Once one reaches supersonic speeds the requirements change. The intake is crucial in controlling airflow into the engine, reducing it's speed to a subsonic level so that the engine can operate efficiently. It's far easier to engineer the required flaps and baffles around a rectangular intake than to do the same with a circular one.

These are the different intake configurations for Concorde at (A) Take-off, (B) Supersonic cruise and (C) Reverse Thrust

(By Nubifer (Own work) [CC0], via Wikimedia Commons)

This is just as true of air intakes on supersonic military aircraft. You'll notice that almost all supersonic military aircraft use some variation of rectangular intakes for this reason.

As with all things aeronautical, there are exceptions. The English Electric Lightning,  Mig-21 and the SR-71 (and numerous others) use circular intakes with the geometry adjusted by a movable inlet cone.

You'll find a more detailed discussion of supersonic intakes in this answer

"MiG-21 RB23". Licensed under CC BY-SA 3.0 via Commons - https://commons.wikimedia.org/wiki/File:MiG-21_RB23.JPG#/media/File:MiG-21_RB23.JPG

"Lockheed SR-71 Blackbird" by Judson Brohmer/USAF - NASA Website Licensed under Public Domain via Commons - https://commons.wikimedia.org/wiki/File:Lockheed_SR-71_Blackbird.jpg#/media/File:Lockheed_SR-71_Blackbird.jpg


Are the PW1100G and PW1400G engine series not certified by the FAA?

They are certified by the FAA. The following 1100/1400 models:

  PW1133G-JM, PW1133GA-JM, PW1130G-JM, PW1129G-JM, PW1127G-JM, PW1127GA-JM, PW1127G1-JM, PW1124G-JM, PW1124G1-JM, PW1122G-JM,PW1431G-JM, PW1431GA-JM, PW1431GH-JM, PW1428G-JM, PW1428GA-JM, PW1428GH-JM

Are certified under TCDS (type certificate data sheet) E00087EN (PDF).

Note: The certificate holder is International Aero Engines, LLC, and I was able to find it by searching https://rgl.faa.gov for "E00087EN", which I got from the neo's TCDS.


How do you calibrate the compass of an aircraft on a compass rose?

Most aircraft compasses include compensating magnets to correct for installation error (due to natural magnetic fields in an aircraft from steel parts and electrical equipment). When installing a new compass or performing significant electrical work on an aircraft the compass may need to be re-calibrated and the compensating magnets adjusted (typically by turning small screws, like the ones shown below).

There are several ways to calibrate (or "swing") an aircraft compass - the use of a properly-surveyed compass rose constructed to applicable FAA standards and marked on an airport is one of them, and ensures the compass swing is being performed in an area free of magnetic disturbances which should result in an accurate calibration.

The basic procedure is to taxi the aircraft to the compass rose and align it with the compass directions using a combination of the ground markings and a "gunsight" compass. A full description of the procedure can be found in AC 43-13.1, Chapter 12-37 ("Compass Swing"), but the quick-and-dirty version is:

Taxi out to the compass rose and align the aircraft so it is pointing toward Magnetic North.

Adjust the compass compensating magnets so that the compass reads North.

Turn the airplane so it is pointing toward Magnetic East (090).

Adjust the compass compensating magnets so that the compass reads East.

Turn the airplane so it is pointing toward Magnetic South (180).

Adjust the compass compensating magnets to remove one half of the "South" error.

Turn the airplane so it is pointing toward Magnetic West (270)

Adjust the compass compensating magnets to remove one half of the "West" error.

Once the compensating magnets have been adjusted a Compass Deviation Card is prepared to inform the pilot of the remaining compass error.
Beginning with Magnetic West (270) turn the aircraft to align with each of the 30-degree lines on the compass rose (270, 300, 330, North, 30, 60, 90, 120, 150, 180, 210, 240), and the error is recorded on a compass deviation card similar to the one shown below.

A compass reading within ±10 degrees on each 30-degree heading marker is considered acceptable per AC 43-13, and better results are usually achieved.

The compass swing is typically performed with the engine and electrical accessories (radios) running per AC 43-13. Some mechanics may also perform a second swing with radios off, and include an alternate deviation card for that configuration.


What is the average cost/timeframe of obtaining a pilot job at a major passenger airline in the US?

The distribution of how pilots get to the majors is bimodal.

If you can get a military pilot slot and give 4-10 years to the USAF, you can then get an FAA ATP and start interviewing at whatever majors are hiring and have your ex-mil buddies on the hiring board. Great way to get in at FedEx or UPS. This costs a few grand for your ATP but that's about it.

If you can't get a military slot, getting up to the point you can instruct from nothing can vary wildly in cost. The accelerated flight training programs will do this for around $70,000. Next you instruct until you hit 135 mins and do either that or instructing. At this point you shouldn't be paying for time anymore. When you get on at a regional you'll sit right seat for a few to many years then you'll upgrade. After about 1.5-2 years in the left seat you'll have the bare minimums to apply at a major.


Why has the IO-390 not replaced the IO-360?

Short answer: OEMs don't see a big enough return on investment (ROI) to justify the change.

Long answer:  Getting an STC is not a simple or cheap process. It costs a lot of money. The recovery off that cost has to be factored into the sales price of the updated aircraft. And there are additional costs associated with supporting a new model of an aircraft -- supply chain, spare parts, warranty, maintenance documentation, flight manuals, etc.

Marketing has to figure how many they can sell at what price. Will it generate new sales in addition to the existing aircraft? Will it cannibalize existing a/c sales? How long will it take to recoup the cost of the change? How much will it add to the bottom line over each of the next 10 years?

Ultimately; what's the ROI? And; is there a better place to allocate our capital for a better ROI?

I'm guessing most OEMs found a better place to spend their development dollars.


What is this odd large sign near Aalborg airport/millitary airport?

It's a maritime navigation aid. I'm fairly rusty, but I'm pretty sure it's a form of lead mark. When seen from the water, as you travel towards the mark, if you keep the diamond centred between the circled dots, it will have you travelling in a straight line down the centre/safest path of a channel.

It will normally be associated with a channel through shallow water, or a hazardous bend, or promontory, or breakwater, or a safe entrance or exit course for a harbour, or similar. Sometimes there may be a progression of such marks to enable zigzagging along an irregular waterway with a minimum of course changes.


When a plane flies faster than the speed of sound, does the distance between plane and sound increase?

I think you are missing some physics knowledge, so let's start from here:

  If a plane flies faster than the speed of sound

Sound is a compression wave that travels through air. Given a certain air temperature, the sound will travel at different speeds through the air.

If a plane flies faster than the speed of sound means that the compression waves it is generating will remain behind the aircraft:

image from here

  will he be able to overtake his own sound and hear itself?

As you can see on the right picture, if the aircraft is travelling faster that the speed of sound, the compression waves it generated in the past will remain behind. If it would stop/slow down, the waves would then catch up with the plane and a person on board would be theoretically capable of hearing them.


What would be the potential effects of not having an accumulator in the hydraulic system?

Accumulators act as storage for flow. At times of peak flow demand, the accumulator delivers a large flow supply at nominal pressure until its oil has been used up, after which the maximum flow is the pump flow. The same functionality that a capacitor or a battery has in an electric system.

If there are no accumulators installed:

Peak hydraulic power is greatly reduced: peak flow supply equals the pump flow, and pressure drops when the pump supplies high flow.
Pressure surges are high when the pump is running and demand suddenly stops, the accumulator evens out the pressure peak, again like how a capacitor functions. (From @Gerry comment).


Can weather groups contain multiple descriptors in a METAR?

No, a METAR descriptor can only appear once in a METAR or line of a TAF. That is because METARs and TAFs report weather phenomena in the format of

[Intensity][Proximity][Descriptor][Precipitation][Obstructions to Visibility].

Thunderstorms, for example, are one descriptor; therefore, thunderstorms (TS) will only appear once.

Intensity

Applies only to the first type of precipitation reported. A “−” denotes light, no symbol denotes moderate, and a “+” denotes heavy.
Proximity

Applies to and reported only for weather occurring in the vicinity of the airport (between 5 and 10 miles of the point(s) of observation). It is denoted by the letters “VC.” (Intensity and “VC” will not appear together in the weather group.)
Descriptor

These eight descriptors apply to the precipitation or obstructions to visibility:

TS = Thunderstorm
DR = Low drifting
SH = Showers
MI = Shallow
FZ = Freezing
BC = Patches
BL = Blowing
PR = Partial

Precipitation

There are nine types of precipitation in the METAR code

RA = Rain
DZ = Drizzle
SN = Snow
GR = Hail (1/4" or greater)
GS = Small hail
PL = Ice pellets
SG = Snow grains
IC = Ice crystals
UP = Unknown precipitation

Obstructions to Visibility
There are eight types of obscuration phenomena in the METAR code

FG = Fog
HZ = Haze
FU = Smoke
PY = Spray
BR = Mist
SA = Sand
DU = Dust
VA = Volcanic ash


Does every Safety–of–Flight Test (SOFT) include full testing of each and every equipment?

Safety of Flight (SOF) Testing is a sample, a subset, of a more exhaustive set of tests.1 It evaluates critical functions that "assures basic" levels of safety for critical components of the system.

The FAA further defines "critical" in this way:
   Usually a function whose loss would prevent the continued safe flight
   and landing of the airplane.2

Though the definition is somewhat circular, it is usually clear when a function is not critical, not required for safety of flight.  For example, a Terrain Awareness and Warning System (TAWS) is not required to be installed, therefore, it's function would not be part of the SOF testing.  However, attitude display, engine instruments, and airspeed are all defined in 2 as critical and would be part of SOF testing.


Should I mention an altitude restriction from the previous controller during an ATC handoff?

There is a bit of a misunderstanding as to what happened here

  Should I have told the new controller I was restricted at or above
  4,500 even though the previous controller didn't explicitly say I was
  restricted (recall she just said, "you can descend to 4500, if you
  want").

You were not restricted to anything (assuming you were within any airspace limitations), flight following is not the same thing as being vectored. Sometimes on flight following you will hear something like

  VFR Altitude At Your Discretion

When you are on flight following you are subject to ATC vectors when they are issued in controlled airspace (A,B,C,D and E) but you are also free to maneuver within the VFR regulations so long as you are not asked to hold a course or avoid a certain area or move for traffic etc.

  you can descend to 4500, if you want

This was not an explicit instruction and not one you needed to comply with nor the floor to which you could come down to technically. They were saying there was no apparent traffic conflicts and if you (for what ever reason) wanted to come down you were clear to at least 4500 ft.

However there are some cases under flight following where you should comply with instructions. Im actually not sure what the legality is on this since you technically don't need to take FF in which case "see ad avoid" is your responsibility. But on any note I have received something like

  Turn left 20 degrees for traffic climbing out of 2500 for 8000

In my experience flying trainer sized stuff in the congested north east corridor, flight following (which ultimate often comes from approach control in this area) will vector you out of the way for jet traffic. Strictly speaking this has occurred in class E airspace where VFR aircraft are largely free to do as they wish.

You may have also been handed off to an angry controller, but you should stick to VFR cruising altitudes when possible as per § 91.159.


Can helicopter rotor produce infrasound?

Yes. Each rotor blade produces a pressure wave. Here's an example from a Chinook:

At a rotor speed of 4 rotations per second, that's 12 pressure spikes per second, or a frequency of 12 Hz. At frequencies that low, you can hear the individual waves rather than a coherent tone (try this Youtube video on a good set of headphones).

At high levels you tend to feel more than hear this frequency: you can feel the pressure variations on your skin, your eardrums and in your lungs, and you could get resonances in your body.


What does the "D" symbol mean on this instrument approach chart?

A [D] symbol is shown to indicate runway declared distance information available, see appropriate Chart Supplement for distance information.

That's from the FAA Aeronautical Chart User's Guide page 124. The wording was different in the 12th edition, it used the A/FD terminology:


Should I log flight time as a passenger?

No, you should not*.

In my opinion, you should limit your logbook to records of your own flight experience. This would include any time spent training, as PIC, or as required crew.

The time you can log as PIC is that which you spend as the sole manipulator of the controls, the sole occupant, or as the pilot in command when the required crew is >1. Here's an article from an FAA FSDO describing the logging of PIC time in more detail. Rod Machado has some good coverage of this as well.

If you're just hanging out in the airplane, it doesn't matter if you're in the front seat or the back seat. If you're receiving instruction, you should get an entry and a logbook endorsement from the instructor you're flying with. Most General Aviation aircraft don't require a type rating, so I'm unsure what the context of your final question is.

* It's worth noting that you can technically put whatever you want in your logbook, though it's not a great idea; when it comes time to fill out an FAA 8710 form for later ratings, it can get confusing. In my opinion, you still shouldn't log any time, but if you're just wanting to record flights that you took with friends, that's fine. As an instructor who's had to slog through some weird logbooks, I'd really, really encourage you to track that elsewhere, though. Your logbook is exactly that - it's your logbook, for the logging of your flight time, and a record of your flight experience and training.


How can you navigate "Writing" onto FlightRadar Plans?

Most Robin 400s don't have autopilots, but some do. Whether it has an autopilot or not it was almost certainly navigated using a pre-set course which was fed into a GPS. One would use flight planning software to create a course using a series of waypoints which would then be uploaded to a built-in or handheld GPS, and then either flown by hand or followed by an autopilot.

You can see that the curves are mostly a series of small straight lines, I think that these straight lines are the space between waypoints, it could be the refresh between the FlightRadar inputs causing the lines though.


Why is the PIC position for helicopters the right seat, rather than the left seat as in airplanes?

The reason is both historical and operational.

The first mass produced helicopter was the Sikorsky R-4.  It had a single collective located between the two pilot seats, so by necessity, the person on the right would control the cyclic with their right hand, and the person on the left would control the cyclic with their left (because their right is needed on the collective).  The cyclic in the R-4 was very difficult to manipulate and required a lot of strength and coordination.  Since the vast majority of student helicopter pilots were right handed, they sat in the right seat, allowing them to use their dominant hand on the cyclic.  Thus, the first generation of helicopter pilots all sat in the right seat, since they all learned on the R-4 (or the R-6).  That's how traditions begin.

The operational applications of sitting in the right seat relate to the inherent instability of a helicopter. A helicopter pilot rarely wants to let go of the cyclic, as it often requires continuous control inputs, especially when hovering. The collective, on the other hand, does not need to be monitored as closely and can be held steady with a friction adjustment, so that hand is occasionally free to manipulate things like radios and other equipment, which are located in the center of the cockpit.

Most helicopters these days have a collective for each seat, located on the left, so the pilot wants to use the hand in the middle of the cockpit to work the radios and things.  Hence, they sit on the right side, which places the collective hand in the middle of the cockpit.

You can read a longer article about this: Why do helicopter pilots sit in the right seat?


Why does the Ka-50 (Hokum) have two main rotors, one on top of another?

The ka-50, like other coaxial rotor designs, use their contra-spinning rotors to cancel out the torque in the same way a traditional helicopter uses it's tail rotor.

A traditional single rotor:

Source

Contra-rotating rotors:

Source

There are a few benefits of the contra-rotating setup, such as

Reduced vibration
Reduced likelihood of settling with power
Reduced likelihood of anti-torque failure during flight.


How do I keep a C172 straight on the centerline during landing/rollout?

My guess here would be that you are not truly tracking the centerline of the runway on final or on roundout.  There’s an easy way to solve that when flying final:  if the runway centerline appears pure vertical from your perspective in the airplane while stationary in your field of view, you are tracking the centerline.  If it has a slight angle to it or is translating, then you’re not totally on centerline.

The differences can be subtle, but can lead to flying a serpentine track toward the runway on final, during roundout, and during ground roll.  It can also result in a touchdown with a slight drift to it which indicates poor piloting technique.

To counter this, first, remember to get the final approach stabilized ie on centerline, on glidepath, and on airspeed as soon as possible after rolling out from the base to final turn.  Remember the more corrections you need to make to do this closer to the runway threshold, the more difficult the approach becomes and the more likely errors in technique will grow unchecked.  Once on a stable final approach, observe the runway centerline and judge if it is a vertical, straight line.  If so, you’re tracking straight down the centerline.  If not, use shallow, coordinated turns to align the airplane so.  This technique will also work when flying a crabbed final in crosswind conditions.

As you roundout, remember you are in slow flight at an increased AoA, so the propeller will tend to pull the airplane’s nose to the left.  Use additional right rudder to prevent this and track straight.

After touchdown, use quick precise feetwork for rudder inputs - think “happy feet happy feet happy feet” - to track centerline.  Also, if doing a crosswind landing, DON’T RELAX AILERON PRESSURE AFTER TOUCHDOWN or the airplane will tend to veer off centerline rapidly.  Remember, fly the airplane all the way through the landing, including the complete rollout.