texts: What is the name for the Mitsubishi A6M Zero's one-piece wing/fuselage?

texts:
The Wikipedia article on Mitsubishi A6M Zero fighter cites an article from Life magazine published on Nov 4, 1942:

  The Zero's fuselage and wings were constructed in one piece, unlike the American method that built them separately and joined the two parts together. The Japanese method was much slower, but resulted in a very strong structure and improved close maneuverability.— Wikipedia

(Source)

This design is harder to implement but it allows for higher strengths for the same weight or lighter weight for the same required strength.

Is there a name for such fuselage design?


texts: In a helicopter does forward flight produce a rolling moment?

texts: In forward flight the advancing blade will produce more lift than the retreating blade. It seems this would produce a rolling moment. If so, does the pilot have to move the cyclic to compensate for this? If it doesn't, why not?


texts: How do airblast fuel atomisers work? Do they simply inject fuel with high velocity? Against the flow or perpendicular to it? How is the fuel jet shaped?


texts: Time Tracking: Does Turboshaft count towards Turbine time?

texts:
another edit
To clarify - I'm programming an application for logbook tracking and want to automate turbine time calculations to help people fill in insurance firms easily.

edit: I guess a more general way to ask this is do you consider turbo shaft to count towards turbine time? Do insurance companies have a standard opinion?

original question:
For insurance forms, when you are asked your turbine time, do you include all of the following in that hour calculation:

Turboprop
Turbojet
Turboshaft

I want to make sure I'm not short changing my time, but don't want to put some helicopter specific turbine in my time if that isn't correct. As far as I'm concerned they should count, right? It is, after all, only asking about the source of thrust not category of aircraft...

Thanks!


texts: Where can I obtain a .KML file for a TRACON’s area of responsibility?

texts: I want an overlay on my moving map for the radar service areas of a TRACON facility.  Are there any sites that host this for free?


texts: How I determine numerically the roll rate of an aircraft?

texts:
I'm a Spanish student of aerospace engineering and I'm doing my final bachelor work that consists in designing an unlimited aerobatic plane, and I wonder if it is possible to calculate an approximation of the roll rate depending on design parameters. ( I have aerodynamic analysis of the wing, CL, CD, MAC, W, ...)

And another question about it, how exactly the trailing edge sweep angle affects the stability? And some bibliography?


texts: Can VOR indication be reliable if one of its antennas breaks?

texts:
What will be the reliability of the VOR indication inside the cockpit if one of the two outside antenna is broken ?

Can we trust it to make a VOR approach?

What will be the consequences assuming that we are in a general aviation aircraft like cessna 150 / 172 / 182 .

Picture of antenna:

(Image Source: http://www.simmer.fr/)


texts: In what manner does the Cockpit Voice Recorder timestamps?

texts:
See here the transcript of ending moments of Aeroflot Flight 593 . The Wikipedia writes :

  (N.B.: All timestamps refer to the flight data recorder time, not GMT or local time.)

What do 2265,2266...2300.....2393..2400 mean? Maybe, they don't mean seconds since CVR can record for only 30 minutes i.e. 1800 seconds..


texts: How should a helicopter pilot react after V-belt breaking?

texts: I have a question concerning the V-belts of the Robinson R22 (or R44) breaking in-flight. When they break, the rotor RPM will drop and the engine will tend to overspeed. (Is this actually correct?) What are the appropriate actions? I know that I need to flare to get rotor RPM back, but do I also need to close the throttle a bit to reduce engine RPM?


texts: Does filing a flight plan with Garmin Pilot activate ACAS and SE-SAR for my inReach?

texts: I have my aircraft set up with a Garmin inReach for ACAS and SE-SAR on 1800wxbrief.com. If I file using the Garmin Pilot app, will the inReach ACAS and SE-SAR work or only if I file on the 1800wxbrief.com site?


texts: What are the extra wheels for on the Harrier series?

texts: On the Harrier series, what are the landing gears on the end of its wings for?


texts: Does headwind on takeoff affect g force?

texts: I'm aware that headwind or tailwind does not affect rate of climb or descent but only the angle. I'm not sure if it affects the g force or not. I'd assume it affects g force because using trignometry, using SIN theta the vertical component increases as the angle increases. However a confirmation would be aappreciated.


texts: Who is the owner of the world's only private Boeing 787 Dreamliner?

texts:
I have just stumbled across this video and I was wondering, if anyone knows who is the owner of this particular airplane (world's only private Boeing 787 Dreamliner)? I mean a man or a company -- an actual user or property owner. Not an airline / operator, because it seems to be Deer Jet.

The video itself does not reveal plane's registration or serial number, so I cannot look it up in any aviation database.

I've tried to locate it in Flightradar 24 database, based on airline / operator -- Deer Jet -- but it lists Gulfstreams and Dassault Falcons only for this operator. Neither Boeing 787 nor any other Boeing.


texts: Which Terminal Arrival Area depiction is correct between NACO and Jeppesen plates?

texts:
Looking at the RNAV (GPS) 19R into Wichita, KS (KICT), the TAA arrival segments are drawn differently between NACO and Jeppesen plates.  Please take note that the TAA arrivals on NACO charts show both the IAF and IF fixes on the arc segment while Jeppesen charts only show the IAF fix.

Which depiction more accurately depicts what the pilots are expected to do from ATC and when would a pilot ever perform the hold in lieu of procedure turn at ACUBO?

Thanks


texts: Are modern Airbus aircraft protected from excessive rudder input?

texts: When in normal Law are Airbus aircraft now protected from the types of excessive rudder input that caused the crash of American Airlines 587 (as dramatized in Mayday, S13E05)?


texts: Could a helicopter fly like a plane this way?

texts:
Could a wing be added to a helicopter to allow the entire craft to tip 90 degrees forward allowing it to fly faster like a plane using a fixed wing and leaning into the wing for lift?

I understand that there would be major modifications to be made but would there be any benefit?


texts: Can I fly for commercial jobs with just my temporary certificate?

texts: I just received my temporary certificate and when I called the airman registry to ask how long it would be before I received my permanent copy, they basically told me it was going to take awhile. So my question is, what can I do with the temporary? Are commercial jobs allowed? Can I apply at private companies to fly for them?


texts: What alternatives to pitot static systems are available or in development?

texts: Air France 447 is a powerful example of what a serious situation unreliable air data indications can be if not handled properly by a crew. Still, whether crews are properly trained or use that training, unreliable air data presents a dangerous situation. Pitot tubes are fallible devices susceptible to errors caused by environmental factors such as ice crystals. With this in mind, what technical alternatives to pitot static systems exist or might be developed that are more accurate and less prone to interruption?


texts: Can a 40 hp ultralight trike with a 15 m wing take off with simple (homebuilt) tube floats?

texts:
There seem to be no floats manufactured for 103 trikes- under 500 pounds including gas and pilot. Seems like they could be smaller and lighter than existing ones.
I am considering fabricating floats primarily for a possible emergency engine out landing along a rocky coast.  Being able to take off would be great, but secondary.  (I would prefer to not turn turtle and sink instantly). I would be landing at about 25 mph

Can a 40 hp trike with a 15 m wing take off with simple tube floats or are stepped hard shell stepped floats necessary?


texts:
According to Reuters, Iran says it refrained from shooting down U.S. plane with 35 on board. The article goes onto say the aircraft was a P-8 Poseidon with 35 on board:

  Iran refrained from shooting down a U.S. plane with 35 people on board
  that was accompanying the downed drone in the Gulf, a Revolutionary
  Guards commander said on Friday...

  Amirali Hajizadeh, head of the Revolutionary Guards aerospace
  division, was quoted as saying by Tasnim news agency: “With the U.S.
  drone in the region there was also an American P-8 plane with 35
  people on board. This plane also entered our airspace and we could
  have shot it down, but we did not.”

I thought the P-8 had a crew of about 12 or so. I thought two or three were flight crew, and the remainder were technicians working with the electronic warfare packages.

Is 35 an accurate number for the P-8?


texts: Using XFOIL to find the angle of attack corresponding to buffet onset and stall

texts: I am trying to find the angle of attack that corresponds to the stall point and buffet onset. I understand for stall this occurs at the maximum lift coefficient? However upon plotting a range of angles on XFOIL it continues to ascend before it reaches a point where convergence no longer occurs so I am unsure what this means.


texts: How much advance notice does the FAA have to give for a TFR?

texts: I recently heard a story from a friend about a pilot that broke a TFR which was issued after takeoff. This sounds suspicious to me that the pilot had no advance notice of the TFR. Is the FAA able to issue an immediate TFR with no advance notice? If so, how can a pilot become aware of these?


texts: Why do spoilers seem to be slightly activated during take off?

texts:
In this video (minutes from 10:46 to 11:00), the spoilers seem to be slightly deployed during take off. What's the purpose of this? I've already seen this in other videos too.

I've also read the answers to the question When can spoilers be used on airliners, but they seem to be related to slowing down the aircraft or for descending faster. But what is the point during take off, when it's supposed the pilots want to climb and go faster?


texts: Is it technically possible to have nuclear-powered hot-air balloons?

texts:
Could a balloon use non-fissile isotope, like Pu-238, to heat air in the envelope to stay afloat for years?

let's put political and health related problems aside, and consider if it's technically possible at all. Say, as an unmanned, high-altitude scientific/weather station.

I know that:

Pu-238 has power output of 0.54 watts per gram
Its half-life is 87.7 years (power output halves after that time).
great most of the energy can be radiated out as heat, and transferred to surrounding air.

I don't know what buoyancy can the hot air balloons provide, and what kind of energy input they require to stay afloat. So - would it fly?


texts: General dimensions for a uav type rc plane?

texts:
I want to build an rc plane that looks like this one

What are the general dimensions that I should follow? I dont want to copy other designs of real uav's and scale them down. A drawing would be great

I want to build something small, wing span should be about 125 cm


texts: Is data approval by DER/DAR still required under new FAR part 23?

texts:
New FAR Part 23 rules have been enacted on August 30th 2017, simplifying certification for small airplanes.

Will the FAA still require:

Designated Engineering Representative (DER) approval for each drawing, and
Designated Airworthiness Representative (DAR) conformity of each part?

This is not required for Light-Sport Aircraft (LSA).


texts: What is the highest service ceiling for turboprop airplane like a Cessna 425?

texts:
What is the highest service ceiling turboprop airplane,  that is fairly small, like maximum of 8 seats, and fairly cheap as well, not going over a million dollars. I looked at Cessna 425, and this plane has a service ceiling of 10km(33000ft), and this plane had the highest service ceiling, that fit the size and cost, that I could find.

So, basically , what plane out there has the greatest service ceiling, that  is small in size, like the Cessna 425, turboprop,  and cheap (under a million) ?


texts:
What are the boundaries of responsibility by the  National Aviation Authorities (Member States of EASA, e.g. France = DGAC) versus the responsibilities of EASA concerning aircraft operations? I know EASA has some responsibility for aircraft operations as noted in EC No 1592-2002, EC 216-2008 and EC 2018-1139. However the National Aviation Authorities (DGAC, ENCA, FOCA, etc.) surely still maintain some operational power or they would cease to exist?

Does anybody have a reference that can clarify whom is responsible for what areas of the "Air Operation" regulations (EASA calls Part 121 "Air Operation") for National Aviation Authorities versus EASA?


texts: What are the ground and flight requirements for high performance endorsement?

texts: I'm told ground is proficiency based but that in the plane you have to fly up to 25,000 feet! I don't know anything short of a turboprop capable of doing that, let alone have the ability to rent it. I'm finding different answers everywhere I look! Can anyone cite the FAR on this?


texts: I want to find out more about Raab Schwalbe Reg SX-AAG

texts:
According to the records on the web, Raab Schwalbe 11 reg SX-AAG was built in Greece in 1935 and sold abroad in 1937.

I know that it was destroyed in a crash on landing in Palestine but I am not sure when that happened.  I originally thought it would have been in 1936 but it may have been later. The picture was taken in Palestine before it crashed.

Does anybody know more about the history of SX-AAG?


texts: After purchasing an aircraft, how do I put the transponder in my name?

texts: I just purchased an aircraft and the prior owner said that I need to put the transponder to my name. What is the procedure to do that?


texts: How are the compressor and turbine disks connected?

texts: What is the typical way the compressor and turbine disks connected to (LP/HP) shaft ? How are the disks connected to each other  (e.g., curvic coupling, bolts or others ?)


texts: How does flying below the freezing level in a thunderstorm help avoid the most critical icing?

texts:
AC 00-6A (Aviation Weather) Chapter 11 states:

Do's and Don'ts of Thunderstorm Flying

To avoid the most critical icing, establish
a penetration altitude below the freezing
level or above the level of -15 C.

I'm trying to understand how flying above an altitude where -15 degrees Celsius occurs would help me avoid icing. I'm also trying to understand how flying below the freezing level would help me avoid icing. What is the explanation?


texts: Can pilots smoke in the cockpit of an airliner?

texts:
An answer on travel.se suggests that some pilots are smoking on long-distance passenger flights.

Can passenger airliner pilots smoke if both the captain and first officer agree it’s ok? If I recall, smoking is only prohibited on flights that require cabin crew as a crew health issue (sidestream smoke) and not as flight safety issue. Given that cabin crew are not on the flight deck, is there anything that prevents a pilot on a larger airline from lighting up?

For the purposes of the question, let’s consider flights originating in  USA, EU, UAE, and China as the four biggest country/areas.


texts: Do any aircraft use throttle steering during normal flight?

texts:
If the engine(s) on one side of a multiengine airplane are set to a higher throttle setting than those on the other side, the airplane (all else being equal) will yaw towards the lower-throttle side; this is best known as a technique for controlling airplanes that have suffered a partial or complete failure of their primary flight control system(s).

Are there any airplanes that make use of throttle steering during normal operation?


texts: How is the emergency exit row handled when there are no passengers aboard eligible to sit in an exit row seat?

texts: Based on Roddy's question about nobody volunteering for the exit row, I can imagine a related but more extreme scenario: what if there are no passengers on the plane who are eligible for an exit row seat? (Say if you had a charter flight full of seniors.)  Do the exit rows simply remain empty in that case? How would the operator ensure that the overwing exits are usable in case they are needed?


texts: Can anyone identify this biplane from 1920s-1930s?

texts: It was my grandfather's, but he is no longer around to ask. He lived in Nebraska.


texts: How much of an improvement would a 1% weight decrease on an airplane be to the industry?

texts: Say I thought of a very easy and inexpensive way to reduce the takeoff weight of a commercial airplane (body, fuel and passengers) by 1%. How much would this mean to the industry? Would it make much of a difference, or would the savings be insignificant enough to not really be worth anyone's time?


texts: What is the purpose of the plush-like seat covers in an airliner cockpit?

texts:
What is the purpose of the plush-like seat covers that I have seen on almost all the airliners I looked at? See for example the following picture of a Bombardier CRJ flight deck:

(wikimedia.org)


texts: Why is the surge line of an aeroengine curved? Why is it not a straight line?


texts: How long does it take to refuel a big jumbo jet? What about a smaller A320?


texts: How is heavy cargo secured in military cargo carriers?

texts:
Some big military cargo carriers carry tanks and other heavy equipment and I am not sure if they have some kind of special locks or tie-downs in the cargo space to manage those heavy loads.

How are these very heavy loads secured?


texts: In the Cl vs Cd graph, Why the drag coefficient decreases initially with the small increment in lift coefficient?

texts:
Cd = Cdo + KCl2

Total drag = Parasite drag + Induced drag

When  Cl = 0 , Cd = Cdo

Increasing in Cl introduces another component of drag (Induced Drag) and therefore the total drag Cd should be increased. But, Why in this plot Cd decreases initially with the small increment in Cl?


texts: Can commercial airplanes be converted to drones?

texts: Is it possible to convert a commercial airplane into a drone, such that if a pilot fails to respond to ATC it can be remotely piloted?


texts: How have fuel consumption and emissions per passenger/kilometre declined since the first jet airliners?

texts:
The efficiency of jet aircraft has improved since the 1960s.

Is it possible to chart figures that show how consumption and emissions of pollutants and CO2, per passenger/kilometre, have declined since then?


texts: What does it mean for a payload to be "caged"?

texts:
If an aircraft has a movable payload (e.g. camera) attached to it, two of the status modes are caged and stowed.

Stowed indicates the payload is retracted and or in a locked position.

What is caged?  I have found reference to "caged" in a couple of resources online, but the do not explain the term.  In some documents about passenger aircraft, it refers to cages in the luggage compartment, but this is completely different.


texts: What is the tolerance of SSR against signal frequency shifts?

texts:
I know that the Secondary surveillance radar (SSR) interrogates at 1030MHz, and the reply is at 1090MHz.

What happens if the radio signal sent to the plane is less than/more than 1030MHz?
Also what happens if the radio signal with which the plane responds is less than/ more than 1090MHz?


texts:
Micro aerial vehicles are a special class of UAVs that have gained a lot of attention and research focus in the past few years. These are generally smaller in size ranging from 3m to 15 cm depending on where you look.

So, is there a clear, recognized or accepted definition of an MAV in terms of size and power? I am interested in the upper limits i.e. the line classifying a UAV as an MAV.


texts: Can a pilot work flight engineer's station?

texts:
In kinda reverse of Did Flight Engineers progress to be pilots?

In three-crew cockpit can a person qualified as pilot work in the position of flight engineer? Does a flight enginner have different qualifications that are not covered by an ATPL, thus rendering a pilot unqualified for the position?


texts: Delta wing flow patterns (straight and yawing)

texts: I was wondering the differences between fluid patterns and their consequences when a delta wing is straight and yawed slightly. Thank you.


texts: Did Clement Ader make the first flight even before the Wright brothers?

texts: Clement Ader invented in the late 1890s, a plane that looked like a bat. It had a steam engine. Witnesses said it went airborne at least once and recorded a distance just over 50 meters. The Wright brothers made their first controlled flight in 1903.


texts:
Can the ILS be manually turned off? Not by the pilots inside the cockpit by simply shutting of the ILS button, but rather by a 3rd party personnel, such as an ATC or a ground crew member.

ATC shuts off ILS on RWY 05L for safety reasons.. or traffic separation reasons.

I am a second year electronics and communications student, so if you would like to use a couple of technical terms, i can understand them, to some extent


texts: Should full flaps be deployed on takeoff?

texts:
Are full flaps ever used on takeoff?

One flying book I read strongly discouraged anything more than quarter flaps on most planes due to the amount of drag produced. I was just wondering if there are any scenarios where full flaps might be necessary.


texts: Does fly-by-wire permit smaller tail fins (area and thickness) for jetliners?

texts:
To prevent an XY problem, here's the context:

A striking feature of the 777 is how small and thin its tail fin is compared to the 747.

When I asked about this many, many years ago, someone told me it's because of the 777's fly-by-wire, which makes better use of small fins. But I started to question that recently.

Above are overlaid scaled drawings (747 and 777). Right away the engine placement seemed to provide the answer: one engine inoperative (OEI) controllability.

Using each plane's lateral engine placement and max thrust (282 kN and 513 kN for the 747-400 and 777, respectively), and with a worst case scenario OEI for the 747 (which would be an outboard engine), the 747 ends up with ~27% more yawing torque. Which would explain the tail fin areas of ~77 and 53 $m^2$.

But (big but), I recalled a famous A340-600 OEI takeoff video (a quad just like the 747 and with equal thrust of ~280 kN), and decided to compare it with the 777-300.

And here the tail fin areas are ~53 (777) and 48 (A346) $m^2$:

So, back to square one.

Of course there's the upper-deck (hump) of the 747; if that is one of the main reasons for the bigger tail, then it still does not explain how the A340 (-500 and -600) manages its OEI by having a smaller tail and more outboard engines compared to the 777.

Is it really fly-by-wire that permitted the smaller fins (area and thickness) of the A345/6 and 777?

One possibility that came to mind is perhaps the use of asymmetric spoilers when an extreme yaw is commanded – which can be seen in the linked A340 video at one moment (before/after the ailerons showed big deflection without the use of spoilers). Of course that presents its own problem: the accompanying roll (and with the video's low-quality and lack of telemetry, it is not really evidence).

Tail fin areas via https://booksite.elsevier.com/9780340741528/appendices/default.htm
Scaled drawings via Boeing and Airbus (for the 777 I used the -300, not the -300ER, in case you're wondering about the wingspan).


texts: Why do aviation careers have age limits?

texts:
Many aviation careers have mandatory retirement ages.

Airline Pilot (licensed with FAA): 65 (raised from age 60 a few years ago)
Controller

FAA: 56
NATS: 60

Why do these age limits exist? Is it a matter of increasing risk (even when one is healthy) of becoming incapacitated while on the job (heart-atack, etc.)?


texts: How do the blades on a propeller generate thrust?

texts:
I am having trouble understanding how this type of propeller generates thrust:

It is so much different than a propeller on a Cessna and thrust would be provided differently. I am also confused of how the turbofan blades in a jet engine provide thrust:

Doesn't the turbofan push the bypass air back really fast providing thrust?  How do each of the these propellers (turbo prop and turbofan) produce thrust?


texts: Can I do an IFR checkride in an airplane that isn't certified for IMC?

texts:
Related to Can a plane be IFR certified, but not allowed in IMC? and Are there any LSA aircraft that can be flown IFR in IMC? .  I understand the distinction between IFR and IMC.  I can train for IFR in such an airplane in non-IMC conditions, but I cannot fly in actual IMC.

Does this mean that I can take my IFR checkride in such an airplane, too?


texts:
32°09'16.6"N 110°50'36.4"W, co-ordinates of the aircraft at Davis-Monthan Air Force base.

Source: Google Maps


texts: Are the airport "taxi" plans available online?

texts:
Whenever I sit in an aircraft and we taxi around the airport, I wonder how exactly is the airport organized, for example, the arrangement of the taxiways and runways.

Is it possible to locate airport diagrams? I'm mostly interested in Paris CDG, Prague PRG and Amsterdam AMS.


texts: What is the meaning of GPS IAP RNP that appears in Notes?

texts:
Referring to the RNAV (GPS) RWY 30 approach, what is the meaning of RNP APCH in the notes section? (Highlighted in YELLOW)
Also, what are the separate DA values in parenthesis? (Highlighted with a red oval)


texts: Why are student pilots' shirt tails cut after they complete their first solo?

texts: There's a standing tradition, at least in the USA, that a student pilot has their shirt cut, signed and dated by their instructor. What is the origin of this practice and what is its significance?


texts: Can large airliners be operated without ground support?

texts:
I'm wondering if large A3x0/B7x7 airliners could be operated without ground support. Short of using the inflatable slides, I guess at least stairs would be required to load/unload passengers. Apart from that, assuming fuel and push-back is not required, would it be possible to land, switch the engines and systems off and then take-off again without electrical, A/C, etc. ground support?

Bonus question:

If possible, are there any circumstances where this is routinely/occasionally done? I know that it's definitely the case for smaller aircraft such as an ATR 72 servicing remote airports - I experienced that at e.g. Luang Prabang airport.


texts: Has any accident been prevented by bending or breaking the rules?

texts:
I wonder if there is an incident that pilots saved the plane or minimized the damage by bending or breaking the rules like Sully? (As it's known Sullenberger started the APU at first which was the 15th thing in QRH.)

Thanks in advance.


texts:
There exist several aircraft - especially carrier-based ones - that have folding wings, to save space.

How is this structure strong, taking into account the considerable amount of force on the hinge-based system (is it?) from the wing loading? How are they prevented from just snapping mid-air?

 Photo by Petty Officer 3rd Class Jason Johnston, U.S. Navy: Public Domain

The same question regarding helicopter rotors too.

 Photo by Lt. Col. Kevin Gross: Public Domain


texts: Why does the A-320 allow 1.3 degrees more left rudder trim than right?

texts:
On the a320, can someone explain why this is:

  AMM 27-22-00 PB 001
  NOTE:The maximum admissible rudder trim limits
  indicated on the control panel when the aircraft is stabilized in
  heading with the AP engaged are RH 1 DEG and LH 2.3 DEG.

Why is there a 1.3 difference in deg between LH & RH?


texts: What kind of horizontal stabilizer does a Boeing 737 have?

texts: Does this plane have fixed horizontal stabilizers and elevators or has it been fixed with stabilators instead?


texts: Do airline pilots increase thrust when ordered to increase altitude by traffic controllers?  Do they simply use flaps, the yoke (or joystick in the case of airbus) and the stabilizers without any increase in thrust.  What is the altitude increase sequence or procedure .  Do they simply rely on auto pilot and if so does it increase thrust too?


texts: How does this RC helicopter keep itself upright?

texts:
I have this (cheap, beginner-level) RC helicopter:

It has 3 controls: one for climbing and descending (collective throttle), one for yawing (differential throttle), and one for pitching (the tail rotor control). There's no roll control.

This helicopter seems to have a very strong tendency to stay upright. Even if you grab it by the skids in mid-air and tilt it slightly, it will right itself (after first flying in whichever direction you tilted it in).

As shown in the picture, the helicopter has two coaxial main rotors and one tail rotor. The tail rotor is pointed vertically, so that it produces a pitching moment. The lower main rotor is fixed-pitch, but the upper rotor has cyclic pitch controlled by a weighted "balance bar". The balance bar itself is mounted about 45° ahead of the rotor. The balance bar is on a hinge so that the ends can move up and down relative to the shaft. If one end of the balance bar goes up, then the blade closer to it is automatically set to a coarser pitch; meanwhile, as the other end goes down, the blade closer to that end is set to a finer pitch.

It seems very unlikely that this helicopter has any electronic accelerometers or gyroscopes.

So, how does this helicopter keep itself upright? Here's what I can figure out myself:

Suppose that the fuselage accidentally rolls to the right while the balance bar remains upright. Then the rotor's cyclic pitch will be set so that each blade is coarsest when it's in the forward right position, and finest when it's in the rear left position. This will produce a left rolling moment, which will tend to bring the helicopter upright again. (It will also produce an up pitching moment... or maybe a down pitching moment, thanks to phase lag? Or no pitching moment at all? I don't know.)
Suppose that the fuselage and the balance bar both accidentally roll to the right. This will cause the helicopter to fly to the right... which will somehow cause it to right itself? But I don't understand the details of why this will happen.

By the way, I've noticed that the helicopter has a tendency to fly in clockwise circles, especially after being disturbed. (It doesn't yaw during this circular motion; it simply moves in a circle while maintaining a constant heading.) I bet that this tendency is caused by the balance bar somehow, but I don't know how.

(Someone may be tempted to answer, "It rights itself because the rotors are above the center of gravity." That explanation doesn't work, though, because the only way an aircraft can right itself is by means of torque. The rotors will generate this torque somehow, but they won't generate it by virtue of being located above the center of gravity.)


texts: What are the requirements for an aircraft to be allowed to perform fast taxi runs?

texts:
In the UK, are any certifications or particular checks legally required for a retired aircraft to perform fast taxi runs (only)?

Would it still be possible to do them if the main wing spars have been cut and shut, for transportation purposes (no ferry flight)?


texts: How can I calculate the relationship between propeller pitch and thrust?

texts:
I am trying to design a WWI propeller so I started calculating. The propeller comes with a specified pitch of 1.75m. The engine is supposed to run at around 1900 rpm and 147kW. These are most likely not the maximums, but I use these values as a starting point.

So I calculated the propeller speed: 1900/60 * 1.75 * 3.6 = 199.5 km/h

I also found on the internet an angle of 16.88 degrees but the site mentions "angle of attack" which I deem incorrect. However if I treat the value as "effective pitch angle" I get about the same speed of ~195.68 km/h (using the formula from Koyovis for Φ from How to calculate variable pitch propeller parameters?).

Everything looks good, my reasoning at this point is that this prop is suitable to be used for the particular aircraft. The speed that I found seems to be reasonable for this aircraft.

But here comes the problem, this is the part that I don't understand and that is 'thrust': if the propeller reaches 1.75 pitch this means that the exit velocity - the input velocity (Ve - V0) is 0!

If I understand the formulas (such as here) correctly this means there can no longer be thrust. How would it possible then that the aircraft is still being pulled forward? This automatically means the aircraft has to slow down. But my assumption is that the propeller is 'designed' to go as fast as the specified pitch.

Can someone enlighten me please. Why does my propeller have to be slower than designed?

edit (I will leave my question above unaltered).
Clarification as per request of JZYL:

The propeller is: AB622
Some of these propellers can still be found on auction sites and such. They have markings like "G 1669 NO 90 DRG AB 662 CRH HISPANO SUIZA, WOLDSLEY VIPER D2400 M/M p 1750 2400mm"

The pitch is 1750mm
The diameter is 2400mm

The aircraft I am looking at is a WWI SE5a with a Wolseley W.4A Viper engine.
It is difficult to state exact parameters. There is a lot of 'belief' of what the aircraft at that time could do.
Some people say the aircraft top speed would be 138 mph (220 km/h). However might as well be one top speed ever recorderd for one plane at excellent flying contditions. Also some people claim the engine could run at 2200 RPM.

So instead I go for some 'safe' or nominal values:
Speed = 125 mph
RPM = 1900

The calculations that I make do not add up. The "pitch speed" (I don't know what the official term is) that I have calculated for the prop is 199.5 km/h (124.6 mph) with these parameters.

But if I have to take slip of say 10% into account (how much is normal, 5% 10%?).
In that case I go down to: 112 mph.

112 mph is way below what people see as the maximum speed of the craft.

So I am basically trying to find a clarification for this.


texts: Are regulations covering private jets different from those covering commercial jets?

texts: Do private jets have relaxed FAA regulations (and regulations imposed by any other aviation agency) when compared to commercial jets? If yes, which aspects of aviation are these relaxations are pertaining to?


texts: Is it easy for a Boeing 747 pilot to get a second typerating on the 777?

texts: Is this easy and responsible? Since the 747 and 777 have a glass cockpit, you would think this would be easy.


texts: Do pilots on approach receive automated warnings of sudden windshear or seismic motion?

texts:
I've read about Windshear Awareness and there is mention of a Predictive Windshear System (PWS) which I believe is a function of the radar system of the aircraft itself.

To complement the reactive windshear system and provide an early warning of potential windshear activity, some weather radars feature the capability to detect windshear areas ahead of the aircraft.
This equipment is referred to as a Predictive Windshear System (PWS).

Are there any gound-based systems that detect possible windshear situations that generate automated warnings directly to planes on approach? Or is the information only distributed verbally by controlers  (e.g. LLWAS)?
Albeit exceedingly rare, are there any automated warning systems to pilots indicating other sudden dangers, for example large seismic motion? For example, the automated stopping of high-speed trains - sometimes before the sesimic wave even reaches a particular train - is being explored (in places where earthquakes and high speed trains are both frequent).


texts: Do adding high thrust in plane prevents it from stalling?

texts:
I am convinced that fighter jets (every flying object) do stall. So from quora, Why don't fighter jets stall?

But most of the fighters have thrust:Weight ratio > 1 which means that they are not following aerodynamics at that time (during vertical climbs). You can consider them to be like rockets with propulsion system.
It suggests fighter planes don't follow aerodynamics. That means stall can be prevented using the jet power. So  what causes them to stall?

Edit: I realized my question is currently away from singularity. Based on comment, jamesqf, zeus and Robert maybe right. That quora answer might be wrong. It claims that fighter jets don't follow aerodynamics. I mean every flying object do follow it. So my question is if fighter jet has enormous power compared to their weight, will it prevent stall by a bit?
My prediction is stall only depends upon AoA. Regardless of airspeed, if AoA exceeds critical angle, stall can't be prevented (even using high thrust propulsion). Only way to prevent stall is to decrease its AoA. Are my claims correct? What if flying object relies on propulsion engine for lift (lot like missile, rocket), they keep flying and nothing hinders their speed?

Stay Safe...


texts: Why high air speed at flat surface don't always produce low pressure?

texts:
Can you explain why flat surfaces don't produce low pressure in both experiments ,even air has high speed in both case?
1)experiment where flat surface DON'T produce low pressure:
http://www.cabrillo.edu/~jwelch/bernoulli/bernoulli.wmv
2)experiment where flat surface produce low pressure:
video 2

3)experiment where curved surface produce low pressure(as always):
video3
If car has flat floor 5cm from ground,will this floor produce low pressure or we must add some curvature to lower pressure?
What is key for low pressure,airflow  speed or airflow curvature?


texts: How does aircraft weight affect landing distance?

texts:
I am a private pilot. I posed a question to instructors in the flight school and got differing answers. For a given aircraft, landing at the same speed, with everything the same except for landing weight, and using maximum braking without skidding the tires, which will stop in a shorter distance after the wheels touch down:  the plane at max gross weight, or the same plane lightly loaded?

I submit that because the heavy plane has more energy to dissipate, it would take longer to stop. Some instructors said that because there is more weight on the wheels, the heavier plane would stop in a shorter distance. I think it is a simple energy conversion physics issue.


texts: Is there an indication in the cockpit when the refueling control panel door is open on the ATR72?

texts: Is there any indication (light, MFD/SD displays) in the cockpit of opened/closed refueling control panel door in ATR72-600?


texts: Why didn’t the Concorde have flap-canards like the Tu-144?

texts:
One of only two ways of which I am aware in which the Tu-144 was “ahead” of the Concorde1 was in its use of retractable flap-canards, which increased the lift on the front of the aircraft at low speeds, thus allowing the aircraft’s elevons to be used as flaperons (flapevons?) for increased lift without pitching the nose down uncontrollably, and, thereby, decreasing the required takeoff and landing speeds;2 the Concorde, in contrast, had no high-lift devices at all as produced.3

Although the Concorde’s myriad aerodynamic advantages over the Tu-144 allowed it to take off and land at much lower speeds than the Soviet SST even without any canards, its takeoff and landing speeds (especially the former) were still very high by airliner standards, with a typical approach and landing speed of 160 kts (296 kph; 184 mph), and a rotation speed, at maximum takeoff weight, of nearly 200 kts (370 kph; 230 mph).  This made the Concorde require very long runways to take off and land (and required the readdition of afterburners in order to keep its runway-length requirements from being even longer), forced the development of a whole new type of brakes in order to be able to stop the aircraft during a landing or rejected takeoff,4 and greatly increased (due to a] centrifugal force, and b] downforce on the main-gear tyres during rotation) the stress on the tyres, and the potential (and actual) destructiveness of a tyre failure.

Why didn’t the Concorde use flap-canards to further decrease its takeoff and landing speeds?

1: The other being the use, in later Tu-144s, of a non-afterburning turbojet.

2: Despite this, the Tu-144 still had a much higher landing speed than the Concorde, thanx to all its other aerodynamic deficiencies.

3: An improved version (the Concorde B) was planned, which would have included leading-edge droops (as well as larger wings and non-afterburning engines) for improved efficiency in subsonic flight and decreased takeoff and landing speeds, but the Concorde programme was cancelled just as the production line was getting ready to build the first Concorde B.

4: Not that I’m complaining about carbon brakes!


texts: Is it possible to get a list of flights at a specific geographic location and specific time?

texts: I would like to know if it is possible to achieve a list of flights that flights above range ring (specific geographic location, range distance), for example the list of flights that passed above London at some date.


texts: How to navigate an aircraft without GPS?

texts:
In case of loss of GPS: how can an aircraft not only be navigated but navigated so precisely that it can pinpoint its destination airport ?

(case in point: Finland and Norway are telling airline pilots to be ready to fly without GPS )


texts: Why is it that only light aircraft are equipped with airframe parachutes?

texts: Why is it that only light aircraft (like Cessnas and Cirrus') are equipped with airframe parachutes? Isn't it possible for at least slightly larger aircraft to have this feature? And isn't there a way to recover the fuselage of a relatively larger aircraft?


texts:
I'm roughly (edit: very well) familiar with flight simulation, but recently I came across a new term. In this brochure (scroll to the second page) by Airbus about flight simulators, they talk about

  Natural Flight Loop models:

  GRM, Aerodynamics...

I've never heard that term before. What does "Natural Flight Loop" mean? Is it Airbus-specific?

(GRM is probably ground-reaction model, aerodynamics is obvious - but that doesn't really explain Natural flight loop, does it?)

EDIT: Ok, "roughly familiar" is a bit understated... I should have made clearer that I'm an aerospace engineer. Actually I have been working on flight dynamics models for simulators myself, so I understand very well, what it needs to develop an accurate flight simulator from a technical point of view (yup - natural flight loop seems to be what is required for FAA FTD Level 6 devices and FFS).

The issue that remains is that I'm curious what this natural flight loop contains in detail.

Is there someone out there who can tell me if this is...

executable code (like a .dll or whatsoever),
mathematical equations (with probably huge lookup-tables for the parameters),
something like Simulink models (or Modelica or ... )?
does it contain separate models for actuators, gear, aerodynamics, weight & balance,...?
does it contain just the open loop model or also the flight control system?


texts: How do diffusers turn velocity into pressure?

texts:
There are many resources that give explanations for the behavior of nozzles and diffusers. But at the crux point they all say, "Velocity goes down and pressure goes up." As if that doesn't warrant any deeper explanation, or as if it were just a law of nature.

To me, the reason behind this energy transfer isn't obvious.

To maintain a constant mass flow rate, $\dot{m}=const$ , through a small inlet and a large outlet you would need a deceleration of the flow. To decelerate a flow requires a force, $F=ma$. Forces interactions are equal and opposite so the fluid would exert a larger force, relative to the inlet, if forced to slow down. But what is the origin of this decelerating force? Why does this geometry increase the $\frac{F}{A}$ of the molecules that pass through it? I understand the energy conservation, but how is this behavior explained in terms of force interactions?

It's like you asked how an electric motor worked and someone said, "By turning electric energy into rotational motion." and you said, "How?" And they just repeat, "By turning electric energy into rotational motion." Energy balance just isn't descriptive enough.


texts: Is a Control Law Degradation in Airbus Planes displayed on the ECAM?

texts:
I would like to know if there is any warning displayed on the ECAM, when control laws get degraded from, let' say normal to direct law, other than the small text on the PFD.

Also if there are any sounds played in the cockpit.

This is because I am at the moment intensively researching myself on XL Airways Germany Flight 888T.
Have there been any software updates, that tell the pilot if the laws are getting degraded since then?

Maybe even because of that crash.


texts: When has China said it will mandate head up displays (HUD)?

texts: I tried to google this but could not seem to get a clear answer.  I was wondering because I heard they first mandated all aircraft by some date which was no where near realistic in terms of cost to the airlines.  They therefore either have reconsidered, or will need to reconsider but I am unclear on it all.


texts: What is this aircraft parked in Oceanside Municipal Airport?

texts:
I was on my way to the beach at Oceanside on October 2020. On 4:32, I saw multiple Cessna or Beechcraft aircraft, as well as a Velocity V-Twin, on the runway of the Oceanside Municipal Airport.
When I was looking at the further spots, I noticed an odd-looking, single-engined twin tail aircraft parked on the runway. As seen in this photo, the red arrow indicates the strange aircraft.


texts: How can air travel be so safe if the aircraft skin is only 1-2 mm thick?

texts:
Aircraft skin is not very thick at all, yet air travel is the safest form of travel. All aviation professionals know why, but most occupants of an airliner are not professionals. How can it be explained to members of the general public that 1 mm is enough to:

Keep the air pressure in.
Keep the wings from breaking off.
Transport the passengers in greater safety than when they travel in their car.

I've used examples like "you can stand on a full beer can but not on an empty one". What are the secrets of aeroplane construction that makes such a seemingly flimsy construction so safe?

Update

How is a stressed skin construction explained to the general public? Lots of non-experts get quite alarmed when they are thinking of crushing a beer can.


texts: How is it possible to perform a rapid climb / tight loop without stalling?

texts:
I'm still trying to get my mind fully around "Angle of Attack". This makes sense to me in the most basic situations, but when I start throwing more dramatic situations at it, my understanding breaks down... which means I don't really understand it.

Take this video for example (at  0:17 and 1:32):

How is this possible? Is it due to the excess power of the aircraft allowing it to change its "flight path" constantly through the maneuver and thus keeping the flight path (relative wind) not far away from the Critical Angle of Attack?


texts: Are you required to disclose medical conditions to your flight instructor?

texts: When talking with a local flight school about my interest in starting training, I started asking questions about how the AME process works. The flight instructor then asked me if I had any specific medical issues. Are you required to disclose any health information to your flight instructor? What about if the issue(s) could be disqualifying? Would you get in trouble for lying to the instructor (to avoid judgement or maintain privacy) but NOT lying during the AME?


texts: What noises are considered worrying on a passenger flight?

texts:
As a typical 'nervous flyer', I often find myself asking crew about a noise that they say is completely normal during flights. The thing is, I've flown a lot and still hear new sounds sometimes!

For example on a recent Easyjet Airbus flight, when the aircraft went into full throttle to take off, a loud whirring/buzzing sound started and lasted the whole flight (I was sat on the wing)... still no idea what that was.

So what is a general list of sounds that are to be expected vs a list that tells you that you are all but doomed :/

Let's keep this to an Airbus Easyjet might use to keep it a short(er) list.


texts: What is this little door on the upper deck of the A380?

texts:
I found a little "door" on the upper deck of this A380:

Source: Airliners.net

What is the purpose of that door, hatch, whatever?


texts: Where do LAX commercial cargo planes land/take off?

texts:
At the Los Angeles airport, do commercial freight planes such as a 777F, 737F etc. take off near the Lufthansa / FedEx / DHL cargo areas from the 25L /25R runways towards the ocean ?

Do they land in the same direction but farther down the runway?


texts: I know the pressure is highest at end of compressor. But what forces air to move low to higher pressure? Am i missing out something? I have heard seals are used to prevent leakage of air from compressor to forward section of engine.


texts: Do the A-320 landing gear extend if the mechanism is activated above a limiting speed?

texts:
I've been told that on the A-320, if the landing gear lever is lowered with the airspeed above a limiting speed, the system will not extend the landing gear. Further, once the aircraft is slowed to an appropriate speed in this condition (i.e. lever down but wheels up), it is necessary to cycle the landing gear lever up and then back down in order to extend the landing gear.

Can anybody confirm or deny, ideally with a reference, if this description is accurate, and if so, what indications accompany such a lever-down/wheels-up condition.


texts:
When I fly 12000ft, how can I know a distance from DME station?
Is there any formula to know or measure distance from DEM?


texts: What type of commercial aircrafts generate strong Wake Turbulence?

texts:
I know that 757, 737 generate strong Wake Turbulence and as pilots, we should always be aware of that and caution for the wake turbulence while landing and departing.

I would like to know if is there like a list of commercial aircraft based on their Wake turbulence generation?  Which one generate the most and which one generate the least? Let's assume they are all heavy, clean, slow!


texts: What does the message content in the ARINC 615A FIND protocol look like?

texts: I know the FIND protocol is used to discover which LRUs are available if the data loader supports the FIND protocol.  I also know the message is sent as a broadcast using UDP, but what is in the message that's being broadcasted?


texts: What would happen if I mounted a system dumping hydrogen (sound velocity 1310 m/s) at the leading edges of an aircraft flying at i.e. mach 2 (ignore all practicality issues)? What would happen at the hydrogen/air interface? Would the aircraft experience wave drag?


texts: Is there always a stall if you exceed a specific angle of attack?

texts:
So lets consider that the stall angle (=Cl max) of a B747 is at 16° (in clean configuration). Does this mean, that, at whatever speed you are flying (i.e. 500 knots), you would stall if you go on a climb angle of more than 16°? So there is no need to always reduce the speed to the stall speed (which might lie at around 150 knots...).
I am just wondering, since, if you fly in the microsoft flight simulator with a big jet, you can have an angle of attack of 30° and more, and not stall until you get to the stall speed.


texts: Can a supersonic aircraft have winglets?

texts:
In order to have laminar flow over the wings which helps in friction drag reduction, a number of airfoil designs have been proposed from the past to the latest 737 winglets.

But if we design a laminar flow wing for supersonic aircraft, the wing should be very thin which will end up with stall and speed related problems.

So, I am curious that if we add winglets on supersonic aircraft, will it be helpful other than for its drag? If so what are all the problems we need to consider?


texts: Why not increase the number of Flight Data Recorders and add jettisoning capability?

texts:
With some Flight Data Recorders gone unrecoverable during crashes , what's the argument for not changing their locations, like wings or engines?

Given their utility after accidents, why not increase the redundancy even more by placing separate boxes in each engine for example.

I understand that military aircraft have jettisoned Recorders  that signal their location for recovery. Could this option be considered with Jettisoned Engines even before the crash in case of Extreme Load or excessive vibrations ?


texts: How does a transonic aircraft gains longitudinal stability

texts: How is the transonic aircraft lift augmentation help in achieving stability


texts: Is an afterburner louder than the same jet engine without it?

texts:
I would speculate that an afterburner increases the noise because it is nearer to the exhaust. But it certainly causes so many changes in the exhaust flow that it could be less loud as well. It may also depend on the shape of the nozzle.

That an afterburner increases the spacial volume of exhaust gases does not necessarily mean that the sound volume increases as well, because it strongly depends on the level of turbulence.

Does activating an afterburner make a jet engine louder? And why?


texts: What is the difference between dry operating weight and dry operating mass?

texts:
What is the difference between dry operating mass and dry operating weight in the context of rotorcraft?

What is the formula for converting mass to weight?


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

texts:
Is there any additional requirement for A&Ps to work on avionics or is that even a totally different license?

I just wonder why only a few A&Ps I met, also do avionics.


texts: How to measure wind speed in a wind tunnel

texts: I'm currently building a wind tunnel that moves air at hundreds of meters per second. How do I cheaply measure the wind speed?


texts: On a commercial airliner, what is the purpose of the flaps? I understand that depending on which direction they move in, they can be used to decrease airspeed, but I don't know when flaps are used. Are flaps used before takeoff, after takeoff and on approach?


texts: What does 'intercept final' exactly mean?

texts:
I work as ATC in Korea. I have question about the exact meaning of the word 'intercept'.

In FAA order 7110.65, 5-9-1 vector to final approach course, "vector to intercept the final approach course", The Korean manual interprets the word of the sentence 'intercept' as "crossing".

I think the word 'intercept' means not 'crossing' but means the state just on the final, not exactly crossing but  just 'established'.

The reason why i have question about this is that in the PAR approach, for precision approach, the final controller can vector aircraft to be exactly on the final beyond the faf although he started control in the state aircraft is not exactly on final.

So I think 'intercept' doesn't mean "crossing" but something else... Because I'm not a native English speaker I want to know the exact meaning of the word 'intercept'.


texts: Why are gate numbers also marked on the outside of a terminal?

texts:
As per this question.
What are these numbers visible from the runway at Narita airport?
A UK document is linked in the accepted answer  but it doesn't list big number marking on the outside of the terminal. Surely such numbering is of little value to pilots- too coarse of location information. So who use such a gate number and how?


texts: What are the ways to perform air traffic control on long distance flights?

texts:
I have a few questions on air traffic control.

From my understanding, there are three major ways of sending control messages to an aircraft:

1) Direct radio link from control as long as the aircraft is in the line of sight.

2) Satellite

3) Ground stations, e.g., TRACON.

My questions are:

a) For an intercontinental flight, how does the control know which ground station to use (since it wouldn't make sense to connect all ground stations to each airport) for control messages?

b) Are the control links (e.g., control-to-ground-station-to-aircraft) to communicate with an aircraft predetermined before take-off?


texts: What kind of helmet is in this A-10 video?

texts:
Here is a screen capture from a YouTube video. The aircraft is an A-10.

What kind of helmet is that and where can I learn more about it?

Additionally, does the weight of the helmet and it's apparently awkward center of gravity cause issues during high-G maneuvers?


texts: Are there any future regulations planned for electric multi-motor LSAs?

texts: It seems with electric control of the multi engine configuration, such as with NASA's new leap tech technology, that there should be a way to use multiple motors in the LSA category. Is there anything in the works regarding regulations for this type of aircraft in the LSA category?


texts: How fixed air, gas and fixed weights in rigid airships is computed in this book?

texts:
I hope I am posting this in the right forum. My current problem is part aviation, part maths.
I have been struggling with the following computation ( Burgess, Charles Paine. Airship Design. Honolulu, Hawaii: University Press of the Pacific, 2004. page 14. The pdf is available at http://www.xlta.org/library/burgess.pdf, note that the first edition of this book was written in 1927. The present snippet uses the typographical conventions from the pdf.)

Problem 1:
Find the volume and horsepower of a rigid airship to carry a military load of 15,000 lbs.at 60 knots (101.3 ft. / sec.). for 60 hours, 85% of the total volume being filled with helium lifting .064 lb./ft.**3 (94 % pure) in the standard atmosphere.
Since the hull is specified in the condition of the problem to be 85% full of gas,
the weight of the gas is 85% D multiplied by the difference between the weight of air and
the lift of gas per unit volume, and divided by the weight of air per unit volume. The total
weight of air and gas is therefore given:

$$
Air\; and\; gas = [ .15 + .85 ( .07635 - .064 ) / .07635 ] \times D = .288 D
$$
While this formula is not an issue, the subsequent formula has been giving me headaches.

From existing data, the fixed weights exclusive of power plant, power cars, and fuel system
equal -3D, and the crew, stores and ballast amount to .055 D. There remains for power plant, fuel, and military load

$$
( 1 - .288 - .30 - .055) D = .357 D
$$
Question is how did the author arrive at this result? Not matter how I approach solving the equation,
I am unable to get the same result. Problem is that the result of this equation is used at a later
stage. I also considered that 1 might be an i, but there was no mention of any constant i in the chapter this formula was taken from. I have no clue what I am missing here.


texts: If we are talking about a slow flying aircraft with subsonic propeller tips, will adding a shroud increase efficiency, all else being the same?(ignoring the friction drag)


texts: ETH 409: Was the most obvious sign of fatigue being a factor due to one of the pilots calling out “go around” when they were climbing after T/O?

texts: One of the pilots yelled out “go around” x6. It looks like they were making a right turn when they should have been making a left turn. The controller informed them for the second time to turn left, and that’s when the callout happened. Is this the most obvious reason for fatigue being a contributor to the accident?


texts: How do I interpret these values in NASA's C-MAPSS dataset files?

texts:
I was studying a dual-speed, high-bypass ratio turbofan engine dataset which I happened to obtain from NASA's website. This dataset was generated from C-MAPSS simulator where dataset has nominal and fault files. I studied the user guide doc and some other documents related to the same but I failed to understand the difference between these two files (ie. at the value/ parameter level).

I have following questions, if anyone has used/aware of this dataset please help me:

difference between nominal and fault file
There are 27 parameteres used, among these which parameters will affect fan, HPC, HPT, LPC, LPT
what is the threshold value for these parameters or when do we say that the parameter has reached its max value and above which it would lead to fault condition.

Here is the link where I got the dataset:
c3.nasa.gov/dashlink/resources/140/


texts: How precise is an ILS (Instrument landing system)?

texts: I read that an ILS is a precision approach system. It provides a final approach with precision in both horizontal and vertical guidance to the runways. But I don't know how precise it is because there were a number of accidents related to landing operations.


texts: Why does AH-64 Apache have its radar over its rotors?

texts:
The targeting radar is above the rotor assembly !

But why ?


texts: Do carrier-less militaries maintain carrier qualifications on allied boats?

texts:
"How do jet fighters get to war?" made me wonder if there was any cross-training for carrier operations between allied nations. While the equipment could be different (see "Do carrier-less militaries retain the equipment for carrier operations?"), do nations that don't operate carriers have pilots with training on it?

For example, are any Australian pilots qualified to land an F/A-18E/F on an American carrier, even if their own plane can't do it?

Example of use would be in an emergency, i.e., land their F/A-18's on a US carrier even though they won't be able to takeoff, and the aircraft will likely need to be shipped.


texts: Are there rules about using the "Fasten seatbelt" sign outside of take-off/landing/turbulence?

texts:
Related to this question regarding flight attendants continuing to stand during turbulence.

My understanding is that it is the law for passengers to be seated with their belts fastened during taxi/take-off/landing along with the flight attendants.

At other times during the flight, the fasten seatbelt sign is also illuminated at times of turbulence/expected turbulence (as per the question linked above, and usually accompanied by a warning from the captain that they're expecting turbulence) - I assume this is subject to the same rules that insist passengers are actually seated during these periods.

On several recent flights on budget airlines (Ryanair/EasyJet), I've begun to notice that the crew are using the fasten seatbelt sign in order to ensure passengers are seated whilst they're serving food/drinks etc. This was confirmed when I was sat at the front of the plane and over heard the cabin crew discussing this.

Clearly, there is a good rationale for keeping passengers seated whilst hot drinks are being served as the aisles on budget planes are too narrow to easily squeeze past, but on Ryanair/EasyJet flights there are also significant times when cabin crew are simply trying to flog cheap perfume and scratch cards.

During these recent flights where the fasten seatbelt sign was illuminated unnecessarily for long periods of time, passengers begun to simply ignore the signs in order to make use of the toilets (especially people with young children etc).

Are there rules that govern when pilots/crew may illuminate the fasten seatbelt signs, and are the passengers breaking any laws by ignoring them?


texts: Why don't pilots parachute from small planes that are in distress?

texts:
There was another question that asked why commercial flights don't have parachutes.  The almost ubiquitous response was that the parachutes would be useless because:

Most accidents with commercial airliners happen on take off and landing, and there is no time to parachute.
In order to get to a position where 100+ people can successfully jump out, you'd most likely need to descend some 20,000 ft and then maintain straight and level for a good 3 to 5 minutes once you got past 12,000 (so people have oxygen to breathe when they jump).  And if you can descend and maintain level flight, you might as well land.

But what about in a light, single engine plane (think Cessna 172 or Piper Cherokee)?  Engine failures in small aircraft, for example, seem to be more common, so you have more accidents that start high above the ground.  Thus, you usually have a few minutes before you're going to hit the ground and there's often only 1 or 2 passengers (rather than 100). Plus, you're usually already at an altitude where you don't need oxygen to bail out.

With that in mind, couldn't you put the plane into a shallow dive to keep it from stalling, trim it to keep it going straight and then bail out?  It seems like a somewhat practical solution, yet I have never heard of anyone doing it.

Why do pilots often try to find a road to land on or a lake to ditch in when trouble strikes instead of just bringing a parachute and bailing out?


texts: Are there pictures of unassembled planes being transported around?

texts:
My google-fu is failing me here.

A friend was telling me about the assembly of carbon-fibre planes, and how the huge parts of these need to be transported long distances between countries.

Are there any photos of this?


texts: What different intake designs are there, and what are their pros and cons?

texts:
I noticed that over the years (on fighter jets specifically) there have been many different methods of directing air into the engines. Primarily, the nose-intake, side intake, and underbody intakes have been very popular with many different designs.

Could somebody explain what the pros and cons behind each type are?


texts:
I was reading the DLE-120 engine User Manual and saw this sentence:

This engine was designed for use in a model aircraft. Do not attempt to use it for any other purpose.

Why? Why not use the engine of a model aircraft for other purpose? What does mean "model aircraft"? Does this mean only RC aircraft or RC and UAVs?
Is there any technical or safety reasons why this engine could not be used in a different application, not involving a model aircraft?


texts: What is the reason Light Sport Aircraft (LSA) minimum speed is limited?

texts:
I saw an explanation about Icon A5 Light Sport Airplane (LSA), it is said that according to FAA regulation, its stall speed NOT LESS than 45 miles per hour (mph) or around 39.1 knots or around 72 km per hour (kmph). Which is mean, its minimum speed is that 45 mph. I was curious that minimum speed is limited.
Than my question is, what is the reason FAA limits the minimum speed of an airplane? Is that stall speed limitation also applied to another type of airplane?

Photo source:
Edit: Some conversion from mph to knot was not clear. Should be 45mph or 39.1 knots.
Edit 2: I added the minimum speed not less than 45mph.


texts: What are the limiting factors for high altitude planes (e.g: U2 or SR71) preventing them from going higher?

texts:
I'm curious as to why planes like the U2 Dragon Lady and the SR71 Blackbird couldn't fly higher. What physical constraint set their operational ceiling?

Pilots wore spacesuits, so that wasn't the limiting factor.  Was the air too thin to give enough lift? Was there not enough oxygen for the engines? Some other reason?

EDIT: My question is specifically about planes designed for high-altitude flight, not for general aircraft. To narrow the scope of my question, consider the SR-71 as the prototypical example. What set the operational ceiling of the SR-71?


texts: Third Class medical license, what changed, if anything?

texts:
Supposedly, in 2016, Congress passed a new law making it easier to fly without the usual medical examination requirements. However, in looking at one of the rather obtuse "FAQs" on this new law, I don't really see what has changed. You still have to have had a medical exam, so new pilots apparently get no benefit whatsoever, they still have to be examined by a doctor. Not only that pilots still have to pass a medical exam at least every 4 years as far as I could tell. So, after years and years of lobbying for a medical-free third class, is the end result that now pilots only have to have an exam every 4 years instead of every 2? Here is an excerpt for the proposed law as I originally saw it:

Fly with drivers license. Did this not happen?


texts: What is the lifespan of an airline engine?

texts:
As per subject, what is the lifespan of a jet engine? Do they have a fixed hours which they can be used and regardless of the state have to be exchanged or are they serviced and maintained until they are deemed not good for use?

If they do have a lifespan, I suppose also that different types of airliner engines and models will have different lifespans.


texts: Can a passenger plane stand still in the air, or hover at a fixed location above a ground?

texts:
This Gizmodo link shows that a commercial passenger aircraft can stay at single location without any movement with respect to ground. (Is it real, an illusion, or faked?)

I have heard a friend saying that this happens for flights into Heathrow airport when the runway is busy with many aircraft required to land. I have argued with him about the holding circuit which basically requires airliner to follow a path around a airport, he is for sure that he has experienced such a thing happening when he was on board and also saw it live many times.


texts: Why is the thrust-specific fuel consumption much worse for high bypass turbofans at cruise?

texts:
General Electric GE90
Takeoff: 0.278 lb/lbf/h (28.3 kg/kN/h)
Cruise: 0.545 lb/lbf/h (55.6 kg/kN/h)
Source: https://en.wikipedia.org/wiki/General_Electric_GE90#Specifications

I assume this is typical for a modern HBPR turbofan.

But why?

Of course, as altitude rises, the reduced air density means the fan has less airflow, causing less thrust to be created. But then again, the bypass ratio does not change, so the core airflow also decreases by the same amount as fan airflow. So fuel flow should be decreasing too! So why is the TSFC TWICE as bad for cruise as takeoff? Is it because of losses in the fan duct increasing rapidly with speed?

(By the way, I know the higher speed helps reduce the seat-mile consumption, but still.)

EDIT: Wait what the? RB211, another HBPR turbofan, has almost no difference between cruise and "sea level" https://en.wikipedia.org/wiki/Thrust-specific_fuel_consumption


texts: What additional aircraft equipment is required to fly a US registered airplane in Europe?

texts:
If I want to take an airplane to Europe, what additional aircraft equipment is required beyond the US requirements?

For instance, I know that we need 8.33Khz spacing radios, what else is there?

Also, I heard that it will be changing in 2015 to have additional requirements.  What will those be, and will there be any exceptions (ie, can we obtain a waiver)?


texts: In the answer to this question the author mentions the chord of a wing.  What exactly is that, and how is it used in wing design?


texts: Why aren't grid fins used as wings for low speed aircraft?

texts:
Grid fins are used "commonly" in aerospace - usually for things like control of guided bombs or spacecraft. The most obvious example is SpaceX's use on the Falcon 9, but the US and Russian militaries have been using them for decades.
My understanding is that there's a tradeoff with grid fins. They offer greater control authority (and/or lift) in a more compact space, and require less torque to turn/reposition than the equivalent wing would. The downside is that they have a lot more drag, and are almost useless at trans-sonic speeds.
My question is: Why aren't they used as wings (to produce lift) on low-speed aircraft and RC drones? I was unable to find any examples of grid fins being used as wings or lifting surfaces. It seems like if it were possible to create more lift in less space someone would have used it in a design. Am I missing something obvious here? I'm guessing yes. :)


texts: What's the name for the structure that helps stop the nose wheel in Boeing 747-400?

texts:
From my understanding the nose wheel of a Boeing 747 does not have brakes, and as such when it is retracted it is still spinning. However, there are two "plates" that make contact with the wheels and slow them down, eventually stopping them.

I am curious as to whether someone could provide some more information about this structure, especially the name.

See the image below:

Thank you!


texts: Are there items bigger than an aircraft section transported by air today?

texts:
This question about engine transportation made me wonder what is the size of the biggest item ever transported. Then I remembered that it should have been a space shuttle (either Buran or the American Space Shuttle), but those items are no longer transported. Nowadays whole aircraft sections are transported, thanks to A300-600ST and B747LCF.

Are there cargo items bigger than a high by-pass ratio jet engine or an aircraft section that are transported by air today (in 2015)? How are those item handled?


texts: What are the two blisters on F-35 upper wing surface?

texts: For all of the F-35 models you can find pictures with and without a blister on the upper wing surface. I'm guessing that it is sensors for the missile warning system that were retrofitted later on, but I couldn't find any information supporting that.


texts: What is the late BF109's (G models) internal fuel capacity? I've been trying to google the answer for a few hours with no luck, perhaps someone here has the right source


texts: What produces thrust along the line of flight in a glider?

texts: After reviewing discussions and vector diagrams of gliders in flight, the vertical lift component and the vertical drag components seem to produce a steady state, 0 acceleration balance with gravity. The glider is on a straight line flight towards the ground. Would the forward motion of the glider be accounted for by combining the horizontal lift vector and gravity? Would any other forces be involved?


texts: Why don't short runways use (downhill) ramps for takeoff?

texts:
This is a followup on question: Why don't short runways use ramps for takeoff?

There are multiple answers to that question that answer why an uphill ramp at the end of the runway does not make sense. But what about going the other way?

I would imagine a downhill ramp at the beginning of the takeoff roll could give the aircraft more energy on takeoff (converting potential energy to speed), and that could indeed improve takeoff performance. This would be useful at places where extending the runway is not possible.

How the aircraft would get up there is another question, but worst case scenario it could always back-taxi on the runway before turning around and taking off.

Is this practice ever used? If not, what are the reasons?


texts: How do I calculate the heading to steer in this example?

texts:
At 1415 an aircraft was overhead a VOR maintaining radial 215°, en
  route for B, heading 210°(M). At 1430, the pilot decides to return to
  the VOR. The heading to steer is...

The answer is given as 040°(M), I'd just like to know the steps to calculate the answer.


texts: Can I be a commercial pilot if I've had a dental filling?

texts: Is there something like a health requirement in serious airlines? Or is it just a myth? How are potential pilots screened when it comes down to physical requirements?


texts: Where is the fuel stored on an aircraft’s wing?

texts: Maybe guys could provide me with a picture I originally thought the anti-shock pads were fuel tanks, but somebody recently told me that they are stored in the wing, so where are they stored at. The aircraft I refer to are like the (b737), (b747-8)(b787)(a-350)


texts: What is the purpose of blades on a compressor?

texts: What is the point of having blades on a compressor. I heard on NASA that it alters the flow but how would this help. As the flow of a fluid increases, the pressure decreases, and vice versa. The rotors increase the speed of the air and descreases the pressure and the stators decrease the speed of the air and increase the pressure. How would this help create higher pressure. Why not just have the rotors? I know that the ducts this whole thing goes in gets smaller as it goes on, does this play a role? Don't get all complicated here on me, I'm still learning about airplanes and flying. Try to be as simple as possible, thank you.


texts: What is the flap extension schedule on approach for an airliner?

texts:
I understand that there are probably no set altitudes and speeds for flaps extensions, but can someone with insight provide a general guide for speeds, altitude and flaps for an ILS approach in good weather for a Boeing 777-300ER with a landing of Flaps 25 and $V_{ref}$ of 147 knots.

Something like this:

Alt: 5000 ft - Speed: 210 kts - Flaps 1
Alt: 4000 ft - Speed: 190 kts - Flaps 5...


texts: Is it legal to use handheld radios to listen to aviation frequencies in the USA?

texts: Is it legal to use handheld radios to listen to (general aviation) airport frequencies in the USA? Can I go to an airport with a handheld radio and listen to their frequencies?


texts: Are there any standards on the dimensions of PFD symbols?

texts:
Are there industry standards on dimensions of PFD symbologies like heading, airspeed and altitude?

I want to design a 15 inch screen and wonder if there are any standards or regulations regarding the design of those information displays.


texts: What happened with flight AC692 to St John's?

texts:
Yesterday, 2nd of March 2020, I was on board of Air Canada flight AC692 from Toronto (YYZ) to St. Johns (YYT). 40 minutes before landing, the plane turned around and flew back to Toronto. The flight time was supposed to be 2:20 hours, instead we flew a round of ~4 hours. The pilot announced that it "unsafe to land" in St John's. But this sounds rather ambiguous to me.

I have a colleague in St John's. He says the there was quite a bit of snow in the morning, but by the time we were in the air, all the roads were clean. This mean they easily could have cleared the runway? Overall conditions weren't too bad and the sky was clear with sun.

Wind would be another condition, but this was a Boeing 777. Those can handle a bit of wind conditions, as opposed to the smaller aircraft types?

Why all the way back to Toronto? Why not divert to Halifax or Montreal and wait until the conditions get better?
I was in the understanding planes don't over-fuel for safety reasons. How did we make it back to Toronto without refueling? If we wouldn't have turned back, would the plane have had too much fuel to land?

I would like to add during the landing in Toronto, flaps were pulled down rather late to my experience. The approach was rather short (in time) and spoilers were used during descend. Also, (almost) no reverse thrust was used used during braking. Does this tell me the plane was running on fumes?


texts: During autoration, does it help to pump the cyclic to increase the RPM?

texts:
I have heard of the idea of moving the cyclic forward and backwards in order to get an increase in rotor RPMs. Does anyone have any information on this as to when you would use it or airspeeds it would only be effective at?

Scenario is low altitude autorotation/unpowered flight:

  About a 100 - 150 feet AGL, super slow (say 10 - 20 kts)
  You lose an engine there.
  The ideal thing would be to get as much airspeed as
  possible to reduce that sink rate as compared to a vertical descent /
  pull collective / do a hard run on.

  However presuming you had to come straight down (trees, power lines or
  whatever) I have heard from more than one source that pushing the
  cyclic back and forth at quick segments will help build RPM's but I
  just couldn't figure out how.


texts: What does an "X" at only one end of the runway mean?

texts:
I came across aerial imagery of a dirt strip in northern Idaho with a white "X" at one end of the runway, but no markings at the other.  Does this mean the runway is only closed in one direction, or that it's fully closed and one of the markings is missing?

Google Maps image: https://www.google.com/maps/@46.0062134,-114.8435236,590m/data=!3m1!1e3!5m1!1e1


texts: Referring to the B737NG, at what point (height) does a TOGA revert to LVL CHG after the takeoff?

texts:
If one takes off with HDG SEL armed and no vertical mode (like VNAV) armed, at what height (AGL) will the vertical mode switch from TOGA to LVL CHG, and what will be the IAS applied?
Also, why isn't it possible to arm LVL CHG before takeoff, as it is with VNAV?
Depending on the entered plan, there are instances when VNAV cannot be armed, even if one wanted to.


texts: Would an area-ruled fuselage improve the MiG-15/17's performance?

texts:
The top speed range of these MiG 15-17 airplanes is in the transonic region, but, when they were first designed, the area rule was unknown.
Even if owning a jet fighter is not exactly 'Maintaining pilot's performance', thus hard to obtain or license, the change looks not too complex to implement; curiosity, experimenting, is the force behind Aviation progress. Salut +


texts: Why aren't there simplified fly-by-wire helicopter controls?

texts:
I was discussing helicopter control with relatives over the holidays, particularly regarding how difficult it is to fly one and how changing any control requires adjusting the other two main controls. One of my relations asked whether any helicopters have a computer control system that automatically compensates, allowing simplified controls that almost anyone could fly.

I replied that I had not heard of such a thing and could only guess why not:

Reliability concerns and possibly pilot training concerns (i.e., you'd have to know how to really fly in the event of a computer failure anyway, so why even have the computer?)
Subtle complexities of the control interactions not lending themselves to reasonable computer automation.

Are there actually no systems like this? Why not? Were my guesses any good?

Regarding the possible duplicate, I saw that question and it seems to indicate that automatic simplified controls would be possible, but it doesn't seem to fully answer the question of why not have a psuedo autopilot that allows a pilot to just push forward on the cyclic to go forward (for example) without having to constantly adjust the collective and rudder at the same time.


texts: What material is used to make luminescent placard on civil aircraft?

texts:
I'm an engineer working in the civil aviation industry. Currently my company is preparing to make some placards. I've downloaded the drawings from Airbus. A drawing calls up the material of AD400 TV25/3881/83. I've seen the original OEM placard and I remember it's luminescent (it's located next to the emergency door).

I've searched "AD400" and "TV25/3881/83" as the keyword on Google but found nothing useful. I think it might be the spec of the material, but what it really is and where I can get it.

It will be greatly appreciated if someone can tell me more info on this material. It would be much better if someone can tell me where I can buy this material.

Update:
Below is how the placard looks like (a screenshot taken from the drawing):

The diamond 12 calls up the material of AD400 TV25/3881/83. Also the drawing says the base material is " MAKROFOL-E". I know "MAKROFOL" is a kind of PC film and it's a trademark of Bayer, but I didn't find this material on the website of Bayer either.


texts: Are there any known instances of airline pilots passing off aerobatics as “turbulence”?

texts:
Inspired by this Far Side cartoon, which shows the pilots of (presumably) a passenger airliner rolling the plane steeply from side to side, and claiming (to the passengers) that they’re just passing through some turbulence.

Are there any known instances of airline pilots actually doing something like that during revenue flights?  Yes, I am perfectly aware that this would be considered highly unprofessional behaviour, and, as we all know, pilots never behave unprofessionally.


texts:
My question is:
Is there any obligation from ICAO about migration from AFTN to AMHS? and If that's so, what are deadlines? Any ICAO doc about this?


texts: Why are passenger seats not facing backward on an airplane?

texts:
In the event of a crash, facing backward sounds much safer:

Forces are applied on a  much larger surface (your whole back is in contact with the seats, instead of just a seatbelt and maybe the opposite seat)
Most passenger are already in position in case of an unpredicted crash.
Passenger without a seatbelt might have higher survival rate

Flying objects would maybe be more dangerous, but

What made designers do it this way ?
Is there any plane with such a configuration ?


texts: What is the minimum radio and navigation equipment for required for VFR and IFR certified aircraft?

texts: As per ICAO or FAA, what are the minimum radio and navigation equipment must be fitted in VFR and IFR certified aircraft and helicopters?


texts: How are emergencies handled during In-Seat Rest?

texts:
Consider a Boeing 737 cruising over the Atlantic when an engine flames out. The procedure here is clear: the pilot flying should continue flying the plane, while the pilot not flying should pull out the QRH and follow the checklist for engine flameout. What happens, though, if the pilot not flying is engaging in Flight Crew In-Seat Rest? I assume they're woken up, and then I see a few options:

the pilot flying continues to fly while the pilot not flying wakes up and overcomes their sleep inertia. After 20 minutes, they go through the engine out checklist
the pilot flying continues to fly while the pilot not flying immediately goes through the engine out checklist, despite the risk of sleep inertia
the pilot not flying immediately starts flying despite the risk of sleep inertia, and the pilot flying goes through the engine out checklist
the pilot flying flies the plane while going through the checklist as the pilot not flying wakes up

These all sound like awful options. So  what would actually happen in such a situation?

Related: Is a pilot allowed to sleep during a flight?


texts: What are the materials used in a tow bar of the pictured design? I am interested in the materials use for the tube (which aluminium alloy?) and the materials of the lunette mount flat and inside structure.


texts: Can I log simulated instrument time in a simulator as a CFII?

texts:
I started working as a flight instructor and have a couple of questions about logging sim time as a CFII:

If I fly a sim session with my student can I log the sim time as dual-given time?
If the sim session was conducted in simulated IMC, can I also log that for myself as simulated instrument time? Or does it only count for the student?


texts: What is the simplest way to explain a sonic boom that is still technically correct?

texts:
I'm looking for an explanation that preserves technical accuracy while remaining brief. Bonus points for including the double boom.

Try to avoid discussing laminar flow and such.


texts: How does p-factor affect jet engines, if at all? If it doesn't, why?


texts: How does a Mach Meter determine the speed of sound at a given altitude?

texts: By my understanding, the Mach Number at a given altitude is calculated by dividing IAS by the speed of sound at that altitude. So how is this speed of sound calculated to display the Mach Number on the Mach Meter? Does the Mach Meter share the same pitot tube used to calculate airspeed?


texts: Why Boeing 737 main landing gear wells have no doors?

texts:
My question is about the Boeing 737 main landing gears:

When the landing gears are up you can see a landing gear door to open in most planes and then it closes. But for Boeing 737 main landing gear are not behind well doors at any time of the flight.

Why are main landing gear wells opened during in flight?


texts:
(Source)
This is certainly not the Ampaire 337 or Electric EEL, which is a converted Cessna 337. It looks like a boundary layer ingestor. Being from Ampaire, it probably is electric or hybrid.
I've tried to find more information about this craft, but failed so far, even from their own website (including the linked page). Google seems to think it's a Learjet. I don't think I've been able to find much, if any other photos of this plane.
The foreground seems to indicate this was a real photo taken from another plane, as you can see window sills, details generally absent in renderings (and many show-off photos). I must admit though, that's not the safest flying around.
Even if it's a rendering, it would probably be a concept. I can't even name the plane yet.
It's beautiful.


texts: Can the safety of the Boeing 777 be extended to other models?

texts:
It is becoming accepted that the Boeing 777 is the world's safest aircraft. There must be a reason for this of course, and aircraft designers should know it.

So my question is, can't we take all the safety merits of a B777 and copy them into other models and bring all airplanes to the same level of safety?


texts: What is special about the ICAO Caribbean region for VFR climb/descent?

texts:
In the FAA JO 7110.65 that provides rules for air traffic control, the following limitations are listed for VFR climb and descent:

  8−8−5. VFR CLIMB AND DESCENT

  a. In the Houston, Miami, and San Juan
  CTAs, IFR flights may be cleared to climb and descend in VFR
  conditions only:
  1. When requested by the pilot; and
  2. Between sunrise and sunset.

The key part here seems to be the second condition, as section 7-1-2 just lists the first one.

  7−1−2. VFR CONDITIONS

  a. You may clear aircraft to maintain “VFR
  conditions” if one of the following conditions exists:
  1. The pilot of an aircraft on an IFR flight plan requests a VFR climb/descent.

So what makes the Houston, Miami, and San Juan areas special that VFR climb/descent must be during the day? Section 8 is the Caribbean ICAO region, which seems to only include the oceanic sections of Houston and Miami. But this rule doesn't specify "oceanic" and none of the other oceanic areas seem to have this rule.


texts: Has anyone attempted to board a flying aircraft mid-air?

texts:
A few movies (e.g. Air Force One, Executive Decision) feature a story where people board a flying aircraft from another flying aircraft.

Has anyone ever attempted, either via docking two aircraft together, using cables, parachuting on top etc., to get from one flying aircraft to another mid-air?


texts: Why would an airport have a beacon light on when there's no traffic?

texts:
I live in a small town (Lone Pine, CA) with a tiny airport that sees a couple planes a week at best... busy-ish days when a major fire is happening. Over the past month the airport beacon light has been running all night long, never stops and I have seen one plane land. This never happened in the past. This just started. The lights shines in my window all night and I am trying to understand the reasoning behind it.

I get airports need to have it on when planes are approaching but the question is why all night with no air traffic? Some say its broken and its supposed to be triggered by oncoming aircraft while other says its FAA regulation to have it on dawn till dusk.


texts: What would the ranks most likely be of the crew of a B-1B?

texts:
I'm currently attempting to write a novel which briefly features a modified B-1B undertaking a risky, highly important mission in support of a Special Access Program. Since a few scenes are set in the cockpit and feature a discussion between the crew, it would be very helpful to know what the ranks of the crew would most likely be.

I've done a little research via a number of sites and e-book previews but so far I've not turned up much other than at least one Lancer pilot who was a Major but I have no idea how the co-pilot, DSO and OSO would compare in rank, or if B-1B pilots of greater rank than Major would be realistic/believable.


texts: Can single engine aircraft fly in class A airspace?

texts:
A friend surprised me the other day by saying that single engined aircraft are not allowed to fly in class A airspace.

I understand that the aircraft is under IFR in class A, with ATC clearance, (flight plan) and must meet PBN specifications, however I can’t find any documentation in my textbooks, EASA or ICAO stating that single engined aircraft are not allowed to fly in class A.

If anyone could resolve this issue it would be much appreciated.


texts: I don't quite understand the various categories of Class E airspace.


texts: Is it quiet in the cockpit when flying faster than the speed of sound?

texts:
Is it quiet in the cockpit when flying faster than the speed of sound or is the noise from air resistance just too loud?

Similar question: is it quieter at the front of an airliner flying faster than the speed of sound because the engines are behind you (comparing to the rear of the plane)?


texts: How is the emergency locator transmitter of the A320 fixed, activated and carried away?

texts:
I've some closely related questions about the emergency locator transmitter, ELT, the "distress beacon", on the Airbus A320. From this question about antennas on the A320:

The ELT antenna seems to be located aft of the cabin.

However the ELT might need to be activated manually in case the acceleration sensor doesn't work. More importantly the ELT must be taken away if the crew/passengers decide to move away from the aircraft wreckage, e.g. after a ditching.

It could be interesting to know some details before being the only survivor of a A320 crash in the middle of the Amazon rainforest:

Were is the ELT located and how is it fixed?
How is it manually powered?
How is it connected to the fuselage antenna and to the overhead panel?
Is it possible to remove it from the aircraft and take it away?


texts: Can a commercial pilot fly passengers for hire without an air carrier certificate?

texts: I have my private multi instrument and almost done with my commercial multi. A collegiate school's football team has requested that I fly the coaches (2-4) to their away games and other travel events throughout the year. Once I receive my certificate, am I legally permitted to fly them for hire without needing an operator's certificate? Maybe through a contract agreement?


texts: Can an instrument procedure be intercepted from the middle and how?

texts:
While I was reading FAA-H-8083-6 I was wondering if a pilot can be instructed to intercept a procedure from a point somewhere in the middle of it.

Specifically:

A pilot departs from an airport having assigned the FOBAR1 SID. There is RADAR service, hence after departure they are vectored to a position outside of that SID. Can the ATC instruct for any reason the pilot to resume the SID? And if this can be done, how is it done? Simply Resume FOBAR1 SID or more specifically eg Fly heading 125, resume FOBAR1 SID or Proceed direct ABC, resume FOBAR1 SID?

NOTE While I mention an FAA document I am mostly interested for EASA and/or ICAO regulations/procedures.


texts: When an alternate minimum applies, does it change MDA or DA?

texts:
In US, the weather minimums for an alternate airport are typically 600-2 for precision approaches and 800-2 for non-precision approaches at ETA, unless otherwise specified at US Terminal Procedure Publication.

When it comes when we actually fly the approach,

a) Is the DA raised to 600 for precision approaches?
b) Is the MDA raised to 800 for non-precision approaches?
c) Is the visibility requirement raised to 2SM for approaches at an airport?

Do alternate minimums work similar to inoperative components, use of alternate altimeter settings, NOTAM to change the actual minimums we use to fly, or a purely preflight planning number for selecting alternate airport?


texts: Does the NTSB provide CVR audio recordings alongside transcripts in accident reports?

texts:
Reading the NTSB's accident report on US1549, there is a transcript of the CVR from page 149 onwards in the PDF (marked as page 130 on hardcopy).

Small clips of the ATC/crew communications exist, but I'm curious to know whether the NTSB also release the full audio recording, per the transcript provided? It's much longer than other clips I can find online.

Related: Can I get official recordings of ATC audio? (asks for FAA, not NTSB).


texts: How to calculate best glide speed at a 30 degree bank?

texts:
The Best Glide speed is the indicated airspeed that guarantees the maximum glide distance during an engine out scenario.  However, the landing straight ahead option after an engine failure may not be the best option especially if there is nothing but houses in front of you after an engine failure.  Sometimes turning back towards the field may be the best option.
The Best Glide speed is actually tied to a best Lift/Drag ratio for a specific angle of attack.  When in a banked turn, the pilot must increase the angle of attack to avoid a spiral dive.  So this implies that the best glide speed would increase during a banked turn in order to maintain the best L/D angle of attack.  My question is how would one calculate the Best Glide speed for an aircraft in a 30 degree bank based off the POH listed Best Glide at Gross Weight (I do realize best glide varies with weight).


texts:
I read on Wikipedia:

  JP-1 was an early jet fuel specified in 1944 by the United States government (AN-F-32). ... It was also known as avtur.

Is AVTUR the same as JP-1 fuel, and the term "AVTUR" is just a nickname?


texts: What radio equipment do pilots use to communicate with ATC?

texts: I know of the transponders used for communication by Air Traffic Control, but apart from that, what radio equipment do pilots use to talk to ATC? What modulation method is used?


texts: Does anxiety increase the likelihood of developing motion sickness?

texts:
In general, does a person's anxiety or "fear of flying" have an effect on his likelihood of experiencing motion sickness during flight?

I am wondering if providing some ground education to first-time flyers would have a positive impact on their experience by reducing anxiety levels and, therefore, the chances of needing to use regurgitation collection devices.

Assume all other factors such as specific G-forces and accelerations experienced, temperatures, meals eaten, etc. are controlled or disregarded.