texts: How can landing in zero visibility be safe?

texts:
I recognise that autoland and ILS can enable landings in zero visibility, which I presuppose in this question (e.g. in this video where touchdown happens around 5:22). Further, suppose that the fog is so thick that runway lights are only visible after touchdown.

Then how would landing be safe or reasonable?
Would such landings recklessly over-rely on and over-trust technology?
Instead, why not wait for increased visibility or divert to another airport?
Or does this sort of landing (video linked above) only occur as the last resort, where the aircraft must land, before depleting fuel?


texts: Why not always take off with 10 degree flaps in a Cessna 172?

texts:
10 degree flaps increase our lift, reduce stall speed, reduce ground roll.
Seems like all advantages with no disadvantages.
So why does the Cessna 172 POH say normal take off is 0-10 degree flaps?
Why not always use 10 degree?


texts:
I've just started working with weather radars and such. With weather radars, it is possible to detect bird migrations with a specific algorithm and a lot of information about birds, but it would be a problem to detect a single bird (depending on the bird size) because of the radar's resolution.

I am wondering, if you have a place or a secret base that you don't really want the population to see whats in that area and take photos of the inside of the area or spy, is there a way to detect small drones with radar signals if you pack a few radars around your place or military base? If so, how?


texts: Operating with BasicMed, may pilot use a medication otherwise restricted under Part 67 Medical Regulations?

texts:
I have a CFI student who is currently using BasicMed to satisfy her FAA Medical Requirement.  She is taking a drug, which the FAA in AME guidance prohibits, and is wondering if she can continue to take that drug.  Going through the regulations, there is no FAR specifically naming drugs, and it appears that for BasicMed, the approval for drug use lies with the examining/issuing physician.

She has gone back to her (issuing) physician and verified that there is no concern with her taking this drug while operating a "vehicle or aircraft" and the physician has confirmed that in the physician's opinion there is no concern.  In her case, her primary care physician (PCP) declined to provide a BasicMed exam, but her endocrinologist agreed to. The drug in question is one the endocrinologist is using to treat her with.

So what we have is a situation where the AME's receive guidance to "Do Not Issue" (DNI) and under BasicMed it appears that the issuing physician can decide contrary to FAA Class 1, 2 or 3 policy.  The question is: Under BasicMed may a pilot be taking a drug, with the approval of their physician, which would otherwise be prohibited under a Class 1,2 or 3 FAA medical?

Addendum: The following is a AC issued shortly before this question was asked:
https://www.faa.gov/documentLibrary/media/Advisory_Circular/AC_68-1A.pdf


texts: Do ICAO specifications have the force of regulation?

texts: ICAO, the International Civil Aviation Organization, has specifications for the conduct of civil aviation throughout the world. Such things as the language to be used between controllers and pilots, aircraft calls signs, and a host of other things are covered. At the time of my retirement in 1999, the ICAO specifications were merely recommendations, they did not have the force of regulation in the U.S. or, to the best of my knowledge, in any country in which I operated. Is that still true? Is there any country that says, essentially, that if ICAO says it should be so, the country treats that as a regulation.


texts: What do taxiway lane, taxiway strip and taxiway shoulder mean?

texts:
I am developing a game which involves an airport simulation. And I am looking into the general rules that traffic control has for busy airports and am also confused on the terminology of a taxiway.

According to ICAO taxiway widths have 3 types of labeling which is as follows:

Taxiway Lane
Taxiway Strip
Taxiway Shoulder

What is the taxiway shoulder? I am fairly sure the lane is the 2 outer yellow lines from the center  taxiway line right? And the strip is the entire taxiway width, but I am unclear on the shoulder label? I could not find an image that showed what this was.


texts: How often is QFE set on an altimeter during flight?

texts:
In countries that use QFE rather than QNH (such as China), how often will a pilot set the QFE setting on their altimeter during flight? Is it only when they intend to land at an airfield, or does it get set for the nearest airfield/aerodrome and updated when entering a new airfields's airspace?

I understand that in the US, QFE is primarily used for airshows and aerobatic competitions, which are presumably operating out of a single airfield and therefore wouldn't be changed in flight.


texts: Was there really a wide gap between the performance of the F-16 similar contestants in the Lightweight Fighter Contest?

texts: Five manufacturers submitted proposals – Vought's V-1100, Lockheed's CL-1200   the Boeing Model 908 and the F-16 and F-17. The F-16 turned out to be an agile dogfighter with "superior acceleration, climb rates, endurance, and (except around Mach 0.7) turn rates"(Wikipedia). Given that the Boeing and Vought designs resembled the F-16, would it be fair to assume that their performance would have been quite similar? Answers would have to be based on the specifications as well as a guess as to agility in combat.


texts: Can air travel cause packaging air pads to burst or deflate?

texts:
This question is a new cross-post from the physics stack exchange: https://physics.stackexchange.com/questions/265884/can-a-decompressed-airplane-cargo-hold-cause-packaging-air-pads-to-burst-defla

I received a parcel from Germany to Chile. The contents were severely bruised due to a lack of packaging material. On second inspection I found a bunch of deflated air pads.

It was a personal shipment, the air pads were used and potentially not in pristine condition, but there were several brands of them, a manufacturing defect can be ruled out. It seems most of them burst, while at least one still had some air remaining and just had a leak that required a bit of pressure to release more air. Surprisingly there was very little air remaining, maybe 20% of the maximum volume.

The contents were light, I doubt they could have damaged a pad at all, let alone destroy them all. Could this phenomena be caused by a pressure difference between the air inside the packs and the cargo plane's hold? It seems a bad explanation considering the popularity of the packaging material.

I did check for needles and dead chicken. ;-)


texts: Feasibility of using secondary props to generate power on an electric model aircraft

texts:
Beginning with the aeroplane itself, it is a small, fixed wing model aeroplane, reminiscent design-wise to a Cessna 172. It is completely battery powered and has a primary prop attached to a motor housed in the nose of the aeroplane.

I was wondering how feasible it would be to attach two props behind the wings of the aircraft, one on each wing, connected to a generator which would then connect to the main battery, so as to recharge the battery while the aircraft is airborne.

I haven't been able to find much information regarding this, so any ideas would be greatly appreciated.


texts:
There is a hole on the belly fairing circled in yellow. I guess is an air intake but I tried searching some info and couldn't find anything.

Source


texts: What is NASR, The FAA's System for Managing Aeronautical Information?

texts:
I've googled this question, and know:

  The National Airspace System Resource (NASR) System provides the Federal Aviation Administration (FAA) with the means for storing and maintaining a reference database with descriptive details of the National Airspace System's (NAS's) infrastructure and the operational status of all components

But what I'm asking is, what does that mean? Is this where companies like AirNav, Jeppesen, and foreflight get their data? When I update my foreflight database, is it downloading new charts and nav data from NASR, or am I misunderstanding the above quote?

Also, related, when Jeppesen makes their own charts, updates them, etc. are they getting their data from NASR, or somewhere else?


texts: Long pole on the tail of a Cessna, what could it be?

texts:
I live just near the finals for our local airport. Today while in the backyard I saw a Cessna fly overhead for landing, it was a tricycle gear and looked like a 150/152, but may have been a 172.
There was a long pole that appeared to be coming out of the tail, although there is a small chance it could have been from the wing on the other side of the aircraft from me. It wasn't very wide in diameter (I couldn't tell even an estimate), was maybe around two-thirds of the length of the aircraft, was painted the same white as the aircraft and capped at the end by a black piece that appeared to be hemispherical.

Does anybody know what this pole could be?


texts: Can an online course replace "ground school"?

texts:
I just found an ad for a "Learn to Fly Course."  Can this course be used INSTEAD OF taking "ground school" at a flight school?  On their site it says:

  Get Your Written Test Endorsement   "... We’ll even give you the
  flight instructor endorsement to take the written test—right from the
  course! You can take this endorsement to the FAA testing center, and
  log it in your ForeFlight logbook."

This seems odd.  The flight school I'm looking at charges $1,000 for a few MONTHS of "ground school" (meeting once per week).  This online course is 25% of that cost and I can study with it 24/7.

What am I missing here?

Note:
This question was reported as a duplicate.  Someone previously asked IF ground school is necessary.  That is NOT what I'm asking here.  What I am asking here is for a COMPARISON between ONLINE ground school versus IN PERSON ground school.  I would like to know if there is some intrinsic value of doing ground school in person versus online or, in other words, if one can adequately replace the other.


texts: What is the difference between turbojet and turbofan engines?

texts:
What is the difference between a turbojet engine and a turbofan engine?

I know that both of them have a fan and have turbines but how to distinguish them?


texts:
How does a company like Martin Baker, evaluate the safety of their ejection seats. Are there any standard metrics or tests that exist? If not, what would be the suggested tests to be performed before they release the seat.

Edit: I am more interested in the type of data they collect from the tests. If I were to create a ejection seat on my own, what quantities would I use it to compare it against Martin Baker's seat?


texts: Do all GA autopilots use cable "clutches"?

texts:
In researching General Aviation autopilots it seems to me that most commonly the way control surfaces are affected is via a servo that attaches (via a clutch) to the control cable. References here and here.

Are there any autopilots that have a servo that directly attaches to, and actuates the control surface(s) as opposed to indirectly via the control cable?


texts: If an airliner turns back midway, how is the route planned?

texts:
There's several incidents of "flights to nowhere", e.g. https://onemileatatime.com/klm-787-nine-hour-flight-to-nowhere/
After a pilot decides to turn back, how is this handled from a routing/flight plan/ATC perspective?  I assume ATC needs a flight plan back to the airport; is this just generated "on the fly"?  Who does this, ATC or the airline's dispatch?
I'm not talking about a diversion to the nearest airport but actually returning to the origin airport after the flight's been underway for a while.  I assume this needs to be coordinated with all the FIRs/centers.


texts: At what distance between two aircraft will the air traffic controller get an alarm?

texts:
I am developing an air traffic control radar simulation.

At what minimum distance between two aircraft in mid-air should a conflict alert be given?


texts: A glider gets the power it needs to fly from the decrease of gravitational potential energy associated to the descent. My question is: for the same weight $W$, airspeed $V$, and a prop efficiency of 100%, is the amount of ‘gravitational power’  $W · w$ that drives a plane in an unpowered glide exactly identical to the ‘engine power’ it needs for s/l, unaccelerated flight?


texts: Why does disk loading mean anything when rotors/propellers are not disks?

texts:
"The helicopter rotor is modeled as an infinitely thin disc with an infinite number of blades that induce a constant pressure jump over the disk area and along the axis of rotation."

This is spectacularly not true of common propeller disks. Most of the area in propeller/rotor disk is empty space, through which air flows freely from top to bottom.

So why do we take this mostly empty disk and use it's area in aerodynamic calculations, when it would seem that we should rather be using the area of the blades themselves?

It seems to permit "fooling" disk loading equations by, for example, decreasing the blade chord without increasing the span, but still getting the same results from equations. So, what a I missing?


texts: When is the descent clearance requested from ATC?

texts: Is there a rule / Standard Operating Procedure as to when request the descent clearance during cruise flight? Something like one minute before reaching the Top of Descent point?


texts: What are the benefits of mounting an engine above the fuselage?

texts:
I'm wondering what advantage/disadvantage, if any, does mounting an engine above the fuselage give? This question comes up after seeing the Macchi M.33 below:

The engine mounted in such a way does look interesting, but I'm wondering if it might make the plane want to dip down slightly. Any help would be appreciated.


texts: What are the aileron lengths of commercial and military aircraft?

texts:
I would like to know the aileron lengths for different aircraft, such as:

Cessna 150
Airbus A380, A320
Boeing 747, 777, 787
Lockheed Martin F-22 Raptor

I have tried to search online, but was unsuccessful in finding the values. I also tried searching in some books but couldn't find the values there either.

Any help guiding me to the books or any resources which would give me the values would be highly appreciated.


texts: Is the ILS CAT III system the most complex landing system available?

texts: Is the ILS CAT III the most technologically sophisticated navigation / landing  system available for helping commercial pilots land a commercial passenger aircraft in severe and extremely low visibility weather conditions. Does the airport require special compatible equipment for this system to work properly?


texts: Fighter jet with two rudders, the deflection angle it is not identical. One have more angle of deflection. Why?

texts: If an aircraft have two vertical tails then pilot push in the  rudder  pedal the rudders will not be deployed at the same angle.It is used throughout the all envelope of flight or is it possible only for low speed? Why and which ones  is  more deflected?


texts: Do jets breaking the sound barrier leave shredded metal on the ground?

texts: As a kid (1960s and 1970s) we would find shredded metal rolled into a loose ball similar to the shredded paper one might find in an Easter basket, in the hills surrounding our farm. We had the Royal Canadian Air Force (RCAF) based about 60 miles north of us in Moose Jaw, Saskatchewan, and the jets used to fly over the farm quite often. We were told that this metal came from the jets when they broke the sound barrier. I can not find any information to confirm this.


texts: Calculate resultant force from pressure distribution?

texts: Can you explain with example how can I calculate magnitude and direction of resultant force from pressure distribution over airfoil?


texts: Is it OK practice to use one altimeter on QFE and one on QNH (local flight, dual altimeters)?

texts:
PPL student, wondering on how this practice is viewed. The aircraft I'm learning to fly in has a small Dynon EFIS which displays horizon, airspeed, heading & altitude. It also has a regular altimeter.

Assuming I'm going for a local flight, returning to land where I departed, is it OK practice to leave the Dynon on QFE and the Altimeter on QNH? This way I don't have to change any settings.


texts: Is there a niche market for A&P mechanics with an aerospace engineering degree?

texts:
I've noticed a few people posting on this site who I would guess are aerospace engineers.

I am an A&P Mechanic, who is currently in the process of applying to college for an aerospace engineering degree.

My question is this:

Does a niche exist that would involve both skill sets, and will the A&P license/experience give me a competitive edge for hiring in some companies?


texts: What is the relation between cargo smoke and EDTO?

texts: I have heard a lot of people discussing about cargo smoke and Extended Diversion Time Operations (EDTO) together. Just want to know how these two affect each other.


texts: Can one pilot lock the other out of the cockpit?

texts:
One seemingly plausible theory about the MH370 disappearance is that one or other of the pilots locked the other one out of the cockpit and then depressurised the cabin.

However, this answer mentions a code that can be entered to unlock the cockpit door. Could this apply in this case (on a 777)?


texts: How to record flights and cockpit radio com using an Android phone?

texts:
I am a student pilot, and would like to record my training flights (in a C152) to look back on. I do not have a Go-Pro, and do not want to fork over the money for one. I do however, own a Samsung Galaxy S5, that has a pretty good camera.

I was wondering if anyone had some ideas as to how I could record my flights using my phone? I have bought a mount, a Y-cable connection for the 1/4"" phone jack, an TRRS cable and a Headphone/Microphone splitter cable for recording the headset audio.

I have, however, noticed that the avionics interferes with the recording and causes the phone to stop recording. Does anyone happen to know why this is?

In addition, this question is not limited to my specific cables/connectors.

Please let me know if anyone has found a working solution with their Android phone in the past. A similar question was answered for IPhone users. Does anyone have experience with Android phones?


texts: How much different are civilian and military aircraft autopilots?

texts: The requirements for military and civil aircraft are pretty different, so this possibly applies to their autopilots. Are they different in the way they function or capabilities that they are programmed with?


texts: Did any metal airplane use a Maxwell slot?

texts:
The Douglas DC-8 used leading-edge slots. Unlike slots in light planes, this one was door operated.
I thought Douglas must have patented it. But as far as I searched, they did not. So it must have been an older design. More researching later, I arrived at a patent, inconveniently titled "Airplane wing", by Frank R Maxwell (image below). Which is the same as the DC-8 minus the pop-out upper part. Earlier designs by Maxwell for this design date back to at least 1928.
And indeed a 1937 NACA report, Wind-tunnel tests of a Clark Y wing with 'Maxwell' leading-edge slots, uses the term Maxwell slot to describe them.

For a given slat size the Maxwell wing with the narrow slat has approximately the same aerodynamic characteristics as the Handley Page type of slotted wing.

Did any metal airplane use a true Maxwell slot? One example would suffice. I haven't been able to find any. I think the 'pop-up part' is important; the DC-8-style slot did not work on the DC-9 without vortilons (during development).


texts: Does a request for a Pop-Up IFR clearance constitute filing a flight plan?

texts:
Introduction

Pop-up IFR clearances are an accepted way to transition from VFR to IFR flight by obtaining an IFR clearance. They are well documented from a controller's perspective in this Tarrance Kramer article appearing in AvWeb and from a pilot's perspective in this Rick Durdan article appearing in AvWeb.

These related Aviation.SE questions also address the topic:

How do you request a “pop up” IFR clearance?
How do you open and get a IFR clearance while in the air?
How should I request an IFR approach at the end of a VFR flight?

Clearly, this is an accepted way to obtain an IFR clearance; I have made use of the option myself plenty of times.

Legal Background

Now, pop-up clearances are often requested and granted with no previously filed IFR flight plan which, on the face of it, would seem to be in violation of 14 CFR 91.173 which states (emphasis mine):

  No person may operate an aircraft in controlled airspace under IFR
  unless that person has—
  (a) Filed an IFR flight plan; and
  (b) Received an appropriate ATC clearance.

14 CFR 91.169 gives the information required for filing that required IFR flight plan, which states, in part (emphasis mine):

  Unless otherwise authorized by ATC, each person filing an IFR flight plan must include in it the following information: [...]

(I omit the long list of actual information)

The Question

The first part of my question is:

Does a request for a pop-up IFR clearance constitute filing a flight
plan?

Is there an unwritten (or perhaps written) understanding that the request for the IFR clearance constitutes filing a flight plan to the extent required by 14 CFR 91.173?

The second part of my question is:

Why is the full list of information required
for filing an IFR flight plan not required, in fact, of a pilot
requesting a pop-up IFR clearance?

If ATC issues an IFR clearance without this information, is that a tacit, but legally valid, authorization to exclude the information otherwise required by 14 CFR 91.169?

Is all this actually codified somewhere that I am not aware of?


texts: Is the aft position the ideal place to fly a large aircraft from?

texts:
Cockpits are at the front of the airplane, and they have pretty limited visibility. Pilot windows can actually open to help with some of this. We know that there are a ton of tricks that are done to assist pilots in navigating their aircraft with the limited visibility that the cockpit provides. The A380 has multiple cameras to assist in visibility. On the ground, there are people to assist in taxing the aircraft.

Has there ever been any research into a flight engineer, or pilot flying an airplane with a VR headset?


texts: Why did air traffic levels decrease dramatically in the US through the 2000s?

texts:
In 2015, the FAA stated that

  System-wide, air traffic has declined by 24 percent since peak year 2000. The chart in Figure 1.1 shows that air traffic
  volume is not expected to return to peak levels in the near term.

This is talking about traffic in terms of ATC operations.

My question: why was there such a drastic, sustained drop-off? I understand that commercial traffic dropped off after 9-11, but I assumed it had since returned to 'normal'. Apparently this is not the case, but are there any other reasons? Is it something with the metric? It doesn't seem like there are any less people flying, do airline fleets consists of larger jets than 15 years ago?

(Info from the Air Traffic Controller Workforce Plan )


texts: What process do flight attendants and pilots follow to bid for routes?

texts:
What process do flight attendants and pilots follow to bid for routes and how does seniority play into this?

Is it the same across multiple airlines/does IATA have a preordained process that airlines are required to follow?


texts: Is high speed buffet possible at supersonic speed?

texts: Since high speed buffet is caused by boundary layer separation due to shock wave and at supersonic flight there is no shock wave directly onto the airfoil (it is attached to the trailing edge), is high speed buffet then possible?


texts: Is it possible to celebrate a holiday twice by flying from one point on Earth to another?

texts:
It recently came to my attention that the different time zones on Earth could allow for a person to celebrate holidays such as New Years twice by flying from one point to another.

Is it possible to fly quickly enough to celebrate a holiday twice?


texts: How can an airliner have low altitude stall recovery?

texts:
I was going through the air crash record and found out that a lot of them happened when the aircraft stalled at a low enough altitude where the pilots couldn't get enough speed to pull back out. I was curious to see why this was the case when I learned about flow separation hysteresis where to reattach the flow the wing needs to pitch down further than the static stall angle. Reading that and the crash record brought up a question in my mind:

How could an aircraft be engineered to have safe low altitude stall recovery? (aside from having a VERY low wing loading, ballistic parachutes, or a computer to prevent pilots from entering low altitude stalls)

From a cursory analysis, this situation seems ideal for some form of emergency engine, either electrically powered fans or a few solid rocket motors to right the aircraft and provide enough power to at least make the touchdown not a crash. Or the wing and stabilizers have some form boundary layer acceleration to reduce the amount of time needed to recover from a stall.

I'm curious to see what approaches have been tried to try and solve this problem or if the newer aircraft have some other technology incorporated.


texts: Why east-bound flight is faster than the reverse flight along the same route?

texts:
Compare

http://www.wolframalpha.com/input/?i=Alaska+Airlines+764+yesterday+duration

and

http://www.wolframalpha.com/input/?i=Alaska+Airlines+771+yesterday+duration

Why the east-bound flight is about 20% faster than the west-bound reverse flight?

Is it because of the average airflow is east-bound?


texts: Can a fighter jet land on a modified airliner?

texts:
Imagine this scenario:

A modified military 747 is flying at a constant speed and altitude. On the top of the fuselage there is a device like a helipad but with three holes to accommodate the fighter jet landing gear, when pressure is applied the holes close, locking the landing gear in the holes. The fighter is flying at the same speed and slightly above. With proper training, is it possible for the pilot to land on the plane and then shut off the engines?


texts: How does a helicopter pilot execute an auto-rotation landing?

texts: What are the critical steps a pilot follows to perform an auto-rotation landing?


texts:
I was wondering how much unusable fuel is in each tank or maybe in total for an A320. I searched through the FCOM and could not find answers.

To add to this question is the fuel shown on the fuel SD page all usable fuel? Or is it unusable + usable fuel?

Please show the references to the answers.


texts: Flight path question? re missing 777 MH370

texts: Can someone explain why the aircraft would fly in an arc using the satellite as a reference point? Have I missed something?


texts: Why would Air France fly to Algeria when it had a civil war?

texts:
I was reading about the Polaris Award that was awarded to the pilots of Air France Flight 8969:

  Algeria was in a state of civil war at the time of the hijacking. Aircraft flying to Algiers faced the possibility of missile attacks. As a result, Air France's flights to Algiers had crews entirely made of people who volunteered for the route. Air France had asked government officials if it absolutely had to continue flying to Algeria; as of the time of the hijacking, but they never gave Air France a reply. Bernard Delhemme was the captain of the flight.[3] Jean-Paul Borderie was the copilot, and Alain Bossuat was the flight engineer.[1] The Airbus A300B2-1C, tail number F-GBEC, had first flown on 28 February 1980.[4]

Please see the question in the title.
Why would rational air crew volunteer to fly to a state with civil war, like Algeria? Did they have optimism bias? How did they underestimate the risk?


texts: In symmetrical airfoils is the stall angle the same for negative AOAs as for positive ones?

texts: In symmetrical airfoils is the stall angle the same for negative Gs as for positive ones? Let say the stall angle is 17 degrees AOA. Is it the same if you push the nose down?


texts: What's the meaning of "the break is a level" in a recovery operation of an aircraft carrier?

texts:
The break is a level, 180° turn made at 800 feet (240 m), descending to 600 feet (180 m) when established downwind. Landing gear/flaps are lowered, and landing checks are completed.

(source: wikimili.com)


texts:
I read through the reference speeds of the Hawker 850XP and I stumbled upon the "Bird Strike Speed". It is specified as "280 KIAS up to 8000 ft".

What does that speed mean?


texts: How do the engines of a multi-engine airplane shut down after fuel starvation?

texts: If a multi-engine aircraft runs out of fuel, can the engines flame out at different times due to fuel inequality between the tanks, or do they both die at the same time because fuel is constantly balanced?


texts:
Wikipedia has this page https://en.wikipedia.org/wiki/Flight_information_region containing a table of all FIR (with ICAO codes) and their respective authority countries.

Is there any place where I can download an updated list like this one as a CSV file (or XML)?

I need to do some automatic calculation of overflight costs. For that I have a set of calculation formulas from IATA, but they are based on authority country, and my input is based on the FIR, that the actual flight is passing through. Therefore I need some way to find the authority country for each specific FIR.

I would prefer somehow to be able to automatically download a fresh list once in a while. I'm not yet sure, how often these data might change.


texts: What were four objects seen in Flightradar24 over Germany with the callsign TWR?

texts: In Flightradar24 from 290030Z and then for two more hours, there were 4 identical objects over Germany between EDFM and EDDS at altitudes from 600 to 1900 feet, a few knots speed and each changing course more than two times per minute but no trace like if stationary. The distance between the objects was about 20km. They all have the same callsign: "TWR". What are they?


texts: Why do children need to leave the plane during a refueling operation?

texts:
On a flight at the end of the 90s,  the plane --  most likely a 747 -- made a stopover at an airport to refuel.

In my recollection, during the refueling process all of the children needed to leave
   the plane. What is the reason for this procedure?


texts: Are there any privately owned large commercial airports?

texts:
Do any large, commercial airports exist that aren’t owned and run by the city government they exist in/near?

To provide context, I’m talking major airports that handle commercial airline volume. Do any (hub or regional) airports exist that are fully owned and operated by private companies vs government authorities? Or is this a total fallacy? I could understand companies big enough to have their own corporate fleet/airstrip, but I’m talking a full-scale airport with airlines the public can use.


texts: What is this airport outside of Cairo, Egypt?

texts:
Out to the east of Cairo, Egypt, is a large two-runway airport that Google Maps calls "Capital Cairo Airport" or "Capital International Airport". Here's a link. However, I can't find any information about this airport or what it's used for. Cairo has a major international airport within the city, here, so I'm confused as to what this large airport only 30-40 minutes away is.

As far as I can tell, it doesn't appear on Wikipedia's List of airports in Egypt, and satellite view shows no planes parked at this airport. Satellite view history in Google Earth shows that two years ago, the airport only had one runway, but since then the second runway was added. So apparently this airport was important enough to merit two runways, both over 10,000 ft. Why? What is it used for? Does anyone know?

30°02'52.55" N  31°49'55.05" E


texts: Why does the diffuser section generate thrust in a jet engine?

texts:
I am studying the thrust distribution of jet engines.
But I'm now a bit confused.

In Rolls-Royce's "The Jet Engine" book,

http://aeromodelbasic.blogspot.com/2012/05/thrust-distribution-distribution-of.html

  At the start of the cycle, air is induced into the engine and is compressed. The rearward accelera- tions through the compressor stages and the resultant pressure rise produces a large reactive force in a forward direction. On the next stage of its journey the air passes through the diffuser where it  exerts a small reactive force, also in a forward direction

I understand the first part of the paragraph that the compressor is providing forward thrust, as it is pushing (so compressing) air rearward. But why is the diffuser also providing forward thrust?
And also why the nozzle is providing rearward thrust?

The similar conculsion is also shown here:
http://www.pulse-jets.com/phpbb3/viewtopic.php?t=2183, that the diffuser is providing positive thrust by calculating the pressure force.

From my understanding of basic fluid mechanics,
shouldn't a nozzle be providing forward thrust, like the sprinkler in the garden or a fire hose?
And shouldn't a diffuser be providing rearward thrust, as the outlet speed is slower than the inlet speed, and so m dot X (v - u) is negative?

What's wrong with my understanding?


texts: How are these flywheel-like devices used in the Boeing 737 Max?

texts:
The recent news video CNN's exclusive look inside a Boeing 737 Max simulator shows a 737 Max simulator cockpit. There are a pair of what look like large black flywheels on the console, shown spinning on their own, and then coming to rest.

What do these do, how are they used, and why is such a large, apparently very haptic device felt to provide the pilot with the best information and/or interaction?

In the real plane (not this simulator) do these connect by cables directly to moving surfaces, or are they actuated only in order to provide information in the cockpit?


texts: Are there any serious plans for a new supersonic civilian aircraft?

texts:
Since the retirement of the Concorde and the Tupolev Tu-144, there aren't any civilian airplanes (passengers carrier or business jet) flying supersonic. I heard that Dassault and SAAB had rather advanced studies on this topic but abandoned them due to various problems.

Does anyone have current references indicating that an aircraft manufacturer plans to develop a supersonic transport aircraft?


texts: Is there a minimum amount of time an airline has to leave between using two identical callsigns?

texts:
Does anyone know if there is a minimum time that an airline has to leave before reusing the same callsign?

I have noticed that airlines reuse callsigns, they usually leave a day or two between reusing them. I'm just wondering is there any regulation on the minimum amount of time that must pass before they can reuse the same call sign again?


texts: How is a turbine engine rotated for starting and inspections?

texts:
I'm doing an assignment for my Level 3 Aeronautical Engineering course and stumbled on this question and I can't seem to answer it (we have had no teacher for 4 months and therefore we have to learn by ourselves):

Name and explain the type of coupling between the main engine rotating
assembly and the accessory gearbox and therefore how a gas turbine
engine is rotated for:
a) engine starting
b) internal inspection (boroscope)

Any help is greatly appreciated.


texts: Is propeller wake turbulence quantifiable based on operating conditions?

texts: I know the propeller does work on the air and thus the flow behind a propeller is higher than the airspeed. However, what is the quality of this flow? If I were doing a heat transfer analysis of an object behind a propeller, other than the accelerated flow speed, the effect of turbulence would matter too, where turbulent flow will contribute towards higher forced convection. I'm not sure how to quantify the added turbulence from a propeller. Is there a simple rule of thumb?


texts: Is it allowed to mount fake missiles on a civilian aircraft?

texts:
In this answer to a question asking to identify an aircraft, we can see a picture of a Aero L-39 Albatros with some missiles hanging from the wings:

(flickr.com) N915WE.

Supposedly, this is a civilian airplane, and another user pointed out the oddity in a comment. The author of the answer then replied that [those missiles] "are as real as this being a USAF L-39 ;)". This second picture shows an airplane with "United States Air Force" painted on it.
Does this mean that it is perfectly legal for a civilian aircraft to mount some fake missiles? And to write "USAF" on an airplane that doesn't belong to the USAF, even? Especially considering this airplane can really be configured as a military one, with real missiles!

To me this looks like going through security checks at the airport with a fake gun in your hands. Sure, it's fake and it can't harm anyone, but I'm not sure the police would appreciate my sense of humour.

Seriously, is this allowed? With all the attention to security (which often borders on paranoia), it is allowed to fly around with fake missiles? Won't this lead to unnecessary confusion, fear, and even false alarms?


texts: What's the speed callout by the PNF on airliners for?

texts:
On all Airliners, there is a speed callout by the PNF at some point during take-off, usually at 80 or 100 KIAS.

Whats the reason for those callouts? And why are some at 80 KIAS and some at 100 KIAS?


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

texts:
Say you had a runway for light aircraft, but only 700 meters or so of runway. Wouldn't it help to end the runway with a ramp that is ~40 meters above ground and slightly facing the sky at a gradient of 5%. Imagine the runway below was 700 meters long:

The point is to put the plane in a position where it is off the ground and in an upwards trajectory so it doesn't have to raise it's own pitch (but still travelling at near-takeoff speed), I think this could be useful with gliders (maybe with some sort of winch to launch it).

If money were no object, what would the flaws be in this sort of contraption? Is there a reason most runways are flat? Is this sort of thing used on any aircraft carriers or other remote-takeoff locations?


texts: Can I measure induced drag with a simple wind tunnel test?

texts:
Device can measures total drag force  and lift of wing for given AoA and airflow speed.
Wing both wingtips are far away from side walls.
Airflow speed is constant all the time:50m/s
TOTAL DRAG=MEASURED DRAG
TOTAL DRAG =ZERO LIFT DRAG + INDUCED DRAG
TOTAL DRAG=PROFILE DRAG +INDUCED DRAG
profile drag=skin friction drag + pressure drag
Step 1.
•First I put  wing at zero-lift angle: it show 500N drag force
Step 2.
•Then I put wing at 15° AoA:it show 700N drag force
Results:
So for 15° AoA and 50m/s:
"Profile drag"(Skin friction + pressure drag) is 500N and induced drag is 200N(700-500).
Is this correct calculation?


texts: Does the headwind component change noticeably when transitioning from a crab to a slip on short final?

texts:
I don't know if I'm overthinking this, but it has been causing a bit of confusion in my head.

Knowing that the headwind component affects the angle of climb/descent, I was wondering how it affects landing when transitioning from a crab to slip technique?

During a crab the nose is facing more into the wind, but when kicking the nose out to align with the runway, I am trying to imagine if that causes a slight loss of lift or a sudden decrease in descent angle? As there would be more of a crosswind component in relation to the direction the wings are facing?

I might be missing something here, but it seems important to know the physics of this when you're only 100 or 200ft above the runway!


texts: How to increase payload capacity of plane?

texts: Keeping thrust, wing span, weight (of plane) constant, can we increase the payload capacity (nearly 50% more)? Adding payload to plane, it decreases thrust/weight ratio, how does it affect the control over plane?


texts: What's for the "smoke fittings" in this muffler?

texts:
Just was reading this manaul => DLE-120 engine User Manual
In this page (pg 4), saw this part:

What's for the "smoke fittings" or "fuel tubing"in this muffler?


texts: Why is the GP7200-powered A380 fleet not grounded?

texts:
After the Qantas A380 engine failure, all Trent-powered A380s were grounded.1

After the Air France A380 engine failure, the GP7200-powered A380 fleet was not grounded.

Why were these two incidents handled differently? And what are the primary drivers for grounding a fleet?


texts: How does a large cargo plane like the C-130 Hercules take off and land in such a short distance?

texts:
So I was at an air show and saw a C-130J Super Hercules showcasing its capabilities.

The take-off distance it covered was amazingly short (I guess equal to fighter jets), even though it uses propeller based engines. The landing was also super short.

My questions are:

How does such a massive plane manage to take off in short distances ? Is it because it has four engines?
During landing, I couldn't see any thrust reverser (as in commercial jets) in play. What tech does it use to stop so quickly?


texts: What was the Vmca of the 2-engine 747 config the El Al 1862 crew faced, and could they have landed the plane at a corresponding Vref?

texts:
In the El Al 1862 crash, the flight crew lost control of their 747 in what basically amounts to an aggravated Vmca roll during approach after two engines detached from the aircraft, causing the loss of two hydraulic systems and damage to flight control surfaces on the right wing.

What was the actual Vmca of the aircraft in that damaged configuration though?  Further, if they had not been focused on trying to get down to a normal configuration Vref and instead sped back up as soon as they started nearing full control deflection, thus increasing their control authority, could they have gone around and then reconfigured partially for what would be an increased Vref, then landed the aircraft at that increased speed?  Schiphol has no shortage of runway, after all...


texts: Why is the front part of the engine not painted?

texts:
The engines are always painted a certain colour but the front part is always grey.

Source

And here on the XWB:

Source

Why is it that?


texts: What is the reason for not providing glide slope guidance on the western approach to Innsbruck?

texts:
When approaching Innsbruck (ICAO: LOWI) from the east, you intercept a localizer (111.10) which also provides glide slope indication. I believe this should be used just for guidance and not for A/P controlled descent.

Making the western approach, you intercept another localizer (109.70) that guides you in the right direction before making the final circling procedures towards the runway. However, this one has no glide slope guidance, and you have to manually compare the current altitude and DME values to the ones in the profile given in the charts (excerpt below) and correct the descent accordingly.

I'm wondering why this is. The descent in the western approach is by no means easier than when coming from the east, see images below.

The approaches differ somewhat in that the eastern localizer gives guidance all the way to runway 26, albeit offset by 5 degrees, but the western localizer is placed far from the airport and is used to get to the start of the circling procedures to either runway.

Could this be the reason that glide slope guidance is omitted, or are there other reasons not to provide this support in the western approach?

Update:
I would like to expand and clarify this question to give it a more general touch. Are there regulations that control the appropriateness of g/s equipment when it comes to the particulars of the terrain or the vicinity to the runway? Are there other properties (geographical or other) that would limit its usability?

Eastern approach profile

Western approach profile


texts: How to take into account man hours in a Service Bulletin?

texts: There are two phrases in any SB included "Total Man hour"and"Elapse time", which quantity should we use in job card for accomplishment an AD or SB?


texts: Why do (some) aircraft shake at low speeds with flaps, slats extended?

texts:
I landed a couple of times as a passenger with the Embraer 190 (I like Embraer very much) on runways with a length below 2 km.

I noticed that the plane started to shake or vibrate quite strongly once reducing its speed prior to landing. The flaps during this time were fully extended. How can one explain these vibrations? I have to note though, that I often sit in the back of the fuselage, where vibrations tend to be more pronounced.


texts: How are pilots alerted to the publication of a NOTAM affecting their flight while in-flight?

texts:
With the length of flights in this day and age, it is possible for an activity to be published in a NOTAM, that NOTAM to be disseminated via the NOTAM system, and the activity to start taking place after a flight whose PIC should have received that NOTAM took off!  Take for instance a by-NOTAM restricted area activation with the minimum 4 hour advance notice, and a 777 whose crew flightplanned through the restricted area based on it being "cold" at the time they briefed their flight, which was oh, another 4 hours before the NOTAM for activating said restricted area was put out.  Keep in mind that the 777 crew took off 2 hours before the restricted area was activated...

How is the flight crew of our hypothetical 777 supposed to find out that the restricted area they were told was cold during their preflight briefing is now hot?  (Of course, this applies to other kinds of NOTAMs as well, some of which can pop up with even less notice; for instance, a mishap-induced runway closure could occur at any time, and a long-haul flight crew would probably rather get that memo before they seek a landing clearance!)

Also, assume this is in US airspace.


texts: Why is it harder to maintain laminar flow on larger aircraft?

texts: I am told that on larger aircraft, suction will be needed to maintain laminar flow because of the larger leading edge radius. Why so? Is it because the air has to travel over a longer distance on the skin, so slows more, and thus piles up toward the trailing edge, causing adverse pressure?


texts: How are Airbus pilots trained for using the mechanical backup control systems?

texts:
The A320 and friends have mechanical-only control capability (manual pitch trim + rudder pedals) for cases of total fly-by-wire computer or electrical failure.  Obviously, this would be covered in ground school when the various control laws are gone through.

However, is any further training given to line pilots on operating the aircraft this way? Or is it one of those "dusty corner" procedures that you learn about in ground school, but never really touch again?

Alternately, what would the chances be of someone who'd never flown a 'Bus in mechanical/backup law being able to keep the plane dirty-side-down and airborne long enough to get the FBW back going and/or perform a landing where the aircraft is reusable?  Clearly, it's non-nil as the Airbus test pilots actually tested flying the plane that way, but how difficult is the aircraft to fly in mechanical/backup law?


texts: Can the removal of a duty-free sales trolley result in a measurable reduction in emissions?

texts:
Recently, SAS announced that:

  Withdrawing tax-free sales will reduce the overall weight of the aircraft, which in turn will reduce fuel consumption and emissions.

I could buy that this might be a polite way to say "we don't make any sales, consequently, the trolley with the items is just ballast; throw it away". It's not the first time that I hear it though: some time ago I remember an article in Aegean's Blue magazine about saving 15 tons of CO2 in one year just by replacing the pilots' flight bags with the electronic equivalent (EFBs). Unfortunately I don't remember in which issue was that.

Now assuming that a trolley weights approximately 25kg empty so let's say 30kg with the merchandise. The L/D ratio of a an Airbus A320 is 16,3 and thus a 30kg reduction in the weight will result in approximately 18,05N reduction in drag and and an equal reduction in the thrust required to maintain the same speed.

Compared to the ~150kN that 2 CFM56-5B4 produce in cruise, The 30 Kg reduction in weight will result in 0,00012% a 0,038% to 0,06% reduction in required thrust (depending on the aircraft gross weight), which seems like a drop in the ocean. Can this make a difference measurable by an airline company at the end of the month/semester/year/century?


texts: In the U.S., Is it ever legal for an aircraft to occupy the runway turnaround area while another is taking off or landing?

texts:
In voretaq7's answer to the question Is there a name for the area for aircraft to back track near the runway threshold?, it is mentioned that runway turnaround areas are considered part of the runway to which they are attached and that any aircraft in the turnaround zone are considered to occupy the runway.

I noticed that in the picture provided in his answer showing a runway turnaround area, the runway edge stripes actually included the runway turnaround area:

However, I've also noted that at the small, uncontrolled GA airport I've most often flown from, the runway edge stripes do not include the turnaround area:

Of course, in either case, a departing aircraft must cross the runway hold line and enter the runway to back-taxi to the turnaround area in the first place. However, I'm curious under what, if any, circumstances is it legal under the U.S. FARs for an aircraft to land or take off on a runway while another aircraft occupies the turn-around zone on that runway? And, of course, I'm talking about normal operations here, not emergencies.

Does the runway edge stripe configuration matter, for example?
How does this differ between controlled and uncontrolled fields?

For the sake of simplicity, let's assume that both aircraft in question are light GA aircraft, not aircraft whose wings might stick off the sides of the runway, and that all parts of the aircraft in the turnaround zone are on the turnaround side of where the runway edge line would be were it a straight line (like it is in the second picture.)

I have seen both landings and takeoffs with another aircraft in the turnaround area at the bottom field pictured above, including a couple of aircraft back-taxiing out there (under mutual agreement and while in radio communication with each other) and the second of them wait in the turnaround while the first takes off.


texts: would a dimpled heat shield reduce heat transfer during reentry?

texts:
Would a large ceramic golfball absorb less heat on reentry than a standard sphere?

"The difference in the flowfields around a smooth sphere and a rough, or dimpled, sphere can be seen above. Since the laminar boundary layer around the smooth sphere separates so rapidly, it creates a very large wake over the entire rear face. This large wake maximizes the region of low pressure and, therefore, results in the maximum difference in pressure between the front and rear faces. As we have seen, this difference creates a large drag like that seen below the transition Reynolds number"(http://www.aerospaceweb.org/question/aerodynamics/q0215.shtml).

Would the reduction in heat absorbed be significant enough to warrant a larger payload via lessening the weight of the heat shield?


texts: How to trigger warnings on an unplugged aural warning unit?

texts:
I got an old 80-0557-11 Rev A manufactured by Grimmes from an EMB-120 Brasilia, and I was wondering how to make it speak.

I powered the component with a 28VDC power supply. It only said "Aural unit Ok" while I was expecting a lot of warnings, due the lack of connected sensors.

Checking an old wiring manual, I realized that most of the sensor inputs have a single connection, not a "HI/LO (+/-)" lines.

Does someone have some idea about how make it play alarms?

Thank you in advance for anyone who can explain me the logic of the system. Please, keep in mind that I'm just a enthusiast trying to better understand how this system works.


texts: How does ATC direct aircraft on ground from the parking to the runway?

texts:
For medium size airports, ATC will direct aircraft with a single message like this "Taxi to runway 29 via Papa, Sierra".

I was wondering if it was the same thing for bigger airports (like international airports) which have a lot of taxiways.

I know that if the pilots are not very familiar with the airport, they can ask for controller guidance. But does the ATC can give all the taxiways points like for medium size airports?

Thank you


texts: Are weather-reporting requirements for an airport in Class D airspace more stringent than for an airport in surface-level Class E airspace?

texts:
In the US, are weather-reporting requirements for an airport in Class D airspace more stringent than for an airport in surface-level Class E airspace?
Are there other requirements that would cause an airport with an operating control tower to be eligible for surface-level Class E airspace but not for Class D airspace?
The intent of the question is to understand why any airport with an operating control tower, whether "temporary" or otherwise, would have surface-level Class E airspace rather than Class D airspace during the hours that the tower was operational, if in fact this ever occurs-- apart from the obvious case of a temporary (or new) control tower going into operation in pre-existing surface-level Class E airspace.
Related ASE links: In the US, are there any operational control towers located in surface-level Class E airspace or in Class G airspace?
This outside link appears to describe the establishment of temporary surface-level Class E airspace concurrent with the establishment of a temporary control tower-- but may just be an example of inaccurate or unclear writing.  The surface-level airspace at this airport is normally Class G, and the same was true in 2016.  The only NOTAM turned up during an archive search for this airport at this time references the temporary control tower, but no temporary change in airspace designation.


texts: What are these openings on the TBD/TBM Avenger?

texts: I've been looking at some pictures and models of the TBF1 and TBM3 Avengers, a torpedo and dive bomber from WW2. I've noticed in some cases there are these openings/slots towards the leading edge of the wing on the top, and it seems as if they pass through to an opening to either the very leading edge of the wing, or just below it. The strange thing is that I've seen many pictures and have noticed that in most models these openings/slots are absent. I'm pretty sure they're more common on the TBM3 than the TBD1, if at all. I was wondering what function these have. I have seen one 3D computer model that shows it's just essentially a rectangularly shaped hole going through the entire wing, though I'm not sure if the modeler just guessed at this. Any ideas of what this might be? You might need to zoom in to see them better.


texts: Do airliners have horns for use on the ground?

texts: When an airliner is on the ground, does it have a way of making a noise that can be heard by other people on the ground? Something like a car horn?


texts: This photo, taken circa 1939, was taken of my uncle's aircraft at Roosevelt Field on Long Island, New York.  Lotar Munch and his partner operated "Munch & Romeo Flying Service" out of Hanger 32. I'm trying to learn more about his business and his aircraft as well.  Note the registration number "NC966V."  I have learned that the "C" indicated that it was a commercial registration. Any help would be much appreciated!


texts: Why is the nose cone of Russian fighters pointing slightly down?

texts:
Let's take SU-30 as an example:

The nose cone is clearly pointing a bit downwards with respect to the level of the engines and wings. Why is this? How can this kind of a banana even fly properly?

Here's the profile an F-18 for comparison:


texts: Can a part 103 ultralight weigh 400kg fully loaded?

texts:
I am designing an electric VTOL personal part 103 ultralight.

My question is: I have 114kg for the ultralight, 100kg for the pilot and 30kg for the baggage. About 260kg is enough to be take off safely but I want to design it up to 400kg.

If I do that, will it still be accepted as a part 103 ultralight and what is the weight limit for it?


texts: Can a vacuum cleaner create sufficient vacuum to operate the artificial horizon?

texts: Inspired by this question about breaking the glass of instruments, I was wondering if a sufficient level of vacuum can be achieved by using a vacuum cleaner on the inlet, or simply sucking through a straw connected to the vacuum inlet, in case the artificial horizon's vacuum pump failed?


texts: Is ATC communication subject to FCC profanity regulations?

texts:
I've never had instance to swear or use profane terminology on ATC frequencies but I've always wondered if the same FCC restrictions which apply to terrestrial entertainment radio stations are in effect for air traffic as well.  I'm guessing that yes, they do and you can run afoul with the FCC over the use of bad language over aviation VHF frequencies?  Does anyone else know about this?

18 USC 1464 seems to spell out a criminal act, but 'any obscene, indecent, or profane thing' is fairly vague language and subject to quite a bit of interpretation.  Is this to be cross referenced against, say, the indecency lines in the Supreme Court case FCC vs Pacifica Foundation in respect to George Carlin's 'Seven Dirty Words'?

Some examples: in the film Threshold: The Blue Angels Experience, an opposing Solo makes the following radio comment while performing the Dirty Loop:

"That's very interesting, boss.  I just got down to 40 knots on the top of that son of a bitch."

And then there are these two potty mouths who work (or used to work) for Southwest Airlines making some less than flattering comments about their coworkers on a hot mike.

Both seem to violate the terms of 18 USC 1464.  Is one more deserving of prosecution than the other?


texts: Is there a use scenario for the Detote value?

texts:
Im currently working on the fuel calculation of an airplane, when i stumbled upon a value called "Detote". When asking around, no one knew what the use case of this value is or why it even exists.

In the handbook it is described as follows:

  A DET (detotalizer) fuel amount is a digital value from which the
  fuel used, as measured by the fuel flow meter, is deducted, allowing a
  comparison to be made with the measured fuel contents.

This value can be set via the UFCP and will show up on the MFD.

What are the application scenarios for the Detote value?
Did you see this value implemented on an aircraft?


texts: I just watched at least 20 airplanes flying northeast over Washington, DC every 15-20 seconds, what were they?

texts: I just watched at least 20 airplanes flying northeast every 15-20 seconds over Washington, DC. They must have been military aircraft since flying very high. I just saw their lights (not blinking). They actually looked like satellites but I doubt so many in the same orbit every 15 seconds.  What is going on?


texts: In helicopters, why not have electric motors controlling blade pitch?

texts:
From my related question comes this idea of electrically controlled blade pitch in helicopters.

Control linkages in helicopter rotors seem to be pretty complex. This surely incurs a lot of friction, especially if you realize that blades have to "flap" back and forth as they rotate around (in order to compensate for retreating blade stall and/or dissymmetry of lift during forward flight). So the swashplate and linkages must surely undergo a lot of friction.

So why not replace all this with electric motors that control blade pitch? They would be small, inside the rod connecting the blade to the hub. No need for any pitch control to be mechanically connected to any other blade(s), so no friction. A computer would control what the pitch should be given the blade's position during its rotation.

This does not mean the main rotor has to be electrically driven. The turboshaft engines can drive the main rotors mechanically as normal. But there would be an electric generator for the blade pitch motors. Note: I'm pretty sure there's already an electric generator on these engines as the computers and radars and stuff have to get their electric power from somewhere.


texts: Why do Boeing and Airbus have distinctively different nose designs?

texts:
Boeing aircraft generally have a pointy nose, which seems to me to imply better aerodynamic qualities, less drag etc. Airbus aircraft on the other hand have rather bulbous noses.

Is this difference to give Boeing and Airbus aircraft a consistent, distinctive visual appearance, or is there any specific aerodynamic reason for the different designs?

This image is only an example and my question is not about any specific model.


texts: How does the B737's 'throttle offline' setting work?

texts:
I'm concerned about this article:

Throttle online means that the crew can override the autothrottle logic, while Throttle offline means that the logic cannot be overridden.

So for example - rejected take-off:
Table shows that at 60 knots 'throttle mode is offline' and we cannot override.
So at 60 knots we can't first move throttle to idle (because it's blocked?) before turning off A/T? Or we can same as at 80 knots?


texts: What is Lower Traffic Area (LTA) airspace in France?

texts:
In France, AIP ENR-2.1 subsection 2.1.2 defines airspaces of type CTA (control area), UTA (upper traffic area) and LTA (lower traffic area).

I'm not familiar with LTA which appears not to exist outside of France and isn't part of AIXM neither. Can anybody fill me in on how LTA differs from CTA and how it could be coded in AIXM?


texts: Is it an acceptable practice to take off in a microburst?

texts:
This video has been posted on Youtube:

Strong winds are blowing at the airfield, pilots are taking off aircraft to prevent them being damaged. However I noticed that gliders have been successfully kept on the ground.

Is that standard practice to take off and fly to try to escape a burst? Is that even allowed and/or sensible?


texts: How realistic is atc-sim.com as an ATC simulator?

texts: I was wondering how realistic https://atc-sim.com/ is.  I only play for fun, not for training, but I want to play as accurately as possible.


texts: What is implied about altitude and the VDP by this Visual Flight Segment arrow in the profile view example in the Aeronautical Chart User's Guide?

texts:
This is out of the Aeronautical Chart User's Guide.

The arrow for the visual segment is depicted as being level flight.  Is that what is intended to be conveyed?  If so, how would you know what altitude?  Would it just be the DA?
LNAV/VNAV would only be second to LPV in vertically-guided precision.  Does this imply that the VDP applies only to an LPV minima, or does the VDP apply to both LNAV/VNAV and LPV minima regardless of the visual segment arrow for LNAV/VNAV??


texts: What is the reason for this engine oil service procedure on a Bombardier CRJ?

texts:
Someone told me that servicing the engine oil on a Bombardier CRJ900 aircraft with the APU on could lead to the particular engine being overserviced. He then advised that the engine-oil service be done within 20 minutes of aircraft shutdown.

What's the reason for this?


texts: Why do pilots use airways instead of just "flying direct" every time?

texts:
These days, on larger/newer aircraft at least, GPS navigation is ubiquitous.  So VORs and Non-directional Beacons (NDBs) are used less.  Wasn't the reason for airways because they were the connection points between VORs and NDBs?

It seems like a pilot could easily "fly direct" from one airport to another without using any intermediary checkpoints.  And yet I've been told on several occasions that most pilots use airways.

Why do pilots still use airways instead of flying direct?


texts: What qualifies as "open water" with respect to FAR 91.119?

texts: FAR 91.119 governs minimum safe altitudes.  It contains a reference to open water.  What qualifies as open water in the eyes of the FAA?


texts:
How are jet engines started? says that engines must be started from bleed air, which can come from the APU, another engine, or a huffer cart, or from windmilling.

As far as I understand, APUs are also jet engines. How are they started? In the air, they must be able to start when both engines are out, so are they able to windmill start? On the ground, can they connect to a huffer cart?


texts: ARINC429 - Encoding and Decoding of BINARY DATA

texts:
In ARINC429 protocol, how to encode and decode FAN DISCHARGE STATIC PRESSURE (LABEL - 127).
Range is 1.5 to 30.0
No of Sig. Bits - 11
Resolution is 0.016
What should be the value to be loaded into the word if my pressure value is 1.5 PSIA ?
As per my calculation, value need to be loaded = 1.5/0.016 = 93.75 which is a fractional value that cannot be loaded. So the value need to be scaled by some value.
Total no of data bits = 19 (including sign bit)
No of bits for representing value = 18
No of Significant bits are 11
Value need to be shifted by (18-11) which is equal to 7 bits => Max value = 128. So scaling factor will be 127 now.
Value before scaling = 93.75
Value after scaling = (93.75 x 128) = 12,000
Value to be loaded (bits-28 to 11) = 00 0010 1110 1110 0000b
But at the decoding side, the value will be decoded as 00 0010 1110 1b (i.e., Only 11 bits of data will be considered for decoding, and rest of the bits will be padding bits).
Decoded value = 00 0010 1110 1b = 93
Decoded Pressure value in PSIA = 93 x 0.016 = 1.488.
Please let me know, encoding and decoding is correct or not ?
Is it OK to take approximate value instead of actual value after decoding ?
What is the use of padding bits. Lets say in this example, i am using only 11 bits for representing a value due to which fractional part is getting discarded. So can i use these padding bits to represent fractional value ? In that case, How the value gets decoded ?
Thanks in advance.


texts: What prevents a propeller from detaching completely from the engine body?

texts: How does a propeller remain attached to the engine? I know there is a gearbox and/or some other mechanism that transmit the movement but is there any security mechanism that avoids it from completely detaching from the main engine? There is a huge amount of forces acting on that tiny spot where the propeller is attached to the engine, especially on turboprops, and this is where my question comes from.


texts: How can I tune a frequency like 121.62 on a comm radio?

texts: On my radio, an ICOM A210, I can't tune 121.62 (the clearance delivery frequency at KMSN). How can I tune a frequency ending in 2?


texts: What does prevent air and fuel to be mixed upstream of the compressor?

texts:
Why isn't fuel injected before the compressor or intake chamber?

The combustion chamber gets a lot of design and clever thinking to be able to mix fuel and compressed air in a short distance/space. This adds more weight and length to the overall engine.

I understand that changing that way of injecting fuel would need a new design and engineering to make it happen, e.g. to prevent blade corrosion, but nevertheless, could it be done?

If someone or a company did it already, and it didn't work, what were the reasons?


texts: Flight Levels shall be transmitted by pronouncing each digit separately. And how should be FL200 transmitted?

texts: It is a huge doubt I have, because I have seen on CAP 413, FL 200, transmitted as flight Level two hundred, and how should then transmit it on Europe (out of UK) and on The USA airspace?


texts: What is the willingness of non-AME/pilot physicians to perform BasicMed exams?

texts:
May 1st, 2017, BasicMed rolls out and for certain operations and certain pilots BasicMed promises a much more permissive and yet preventive oriented approach to medical approvals for pilots.

A concern is that one's physician may not issue BasicMed.

From AAFP's newsletter, where BasicMed was overviewed for Academy members (mostly Family Practice Physicians), I have extracted the following excerpts.

  In an interview with AAFP News, Cowl stressed that physicians should
  understand FAA medical guidelines as they pertain to potential
  liability.

  "There is the potential for liability to physicians, in part because
  the pilots most likely to use the alternative qualification pathway
  may be the very people who need the standard flight physical," said
  Cowl.

  ...

  "At that altitude and type of airframe, these planes are sharing the
  airspace with paying commercial passengers. As physicians, we need to
  maximize the health of our patients and promote aviation safety," he
  said.

  Simply put, "This comprehensive medical checklist is not a summer camp
  physical," said Cowl. Physicians should familiarize themselves with
  FAA guidelines, communicate with aviation medical examiners in their
  communities and understand the liability they take on when they put
  their medical license number on the FAA form.

  Cowl acknowledged that some family physicians may already perform
  commercial truck and bus driver examinations that are similar in
  nature to pilot exams. For those physicians, a certain comfort level
  may already exist.

  However, he added, "Physicians who do these exams need to be cognizant
  of the 'ask' -- and that is to perform a comprehensive exam and then
  sign an attestation statement that says, 'Based on my comprehensive
  exam, this person is safe to fly.'"

So I asked my non-pilot family practice doc whether he would be doing BasicMed exams.  "Absolutely not.  Truck drivers are one thing, but flying planes and the liability potential is too great for me to stomach."

I asked another FP doc, and she told me that she would avoid doing the exams, because as she understands them, they require a comprehensive physical that has higher complexity than other physicals she performs, and along with it there is an unknown liability potential, which is new to the risk market and she doesn't like being a guinea pig.

Then I talked with a former student of mine, who is an emergency medicine attending, and holds a Private Airplane-Instrument certificate.  He has been tracking BasicMed, because it is relevant to him.  He hauls his family around at vacation time in his Saratoga, and BasicMed meets his requirements. "Honestly, I will just see (my AME) and get a regular third class medical.  I don't know anyone who wants to touch BasicMed if they are in private practice.  If you get someone working for a hospital clinic, it might be different."

So my question is: Is there any preliminary data on the willingness of physicians to perform BasicMed exams, and in particular those who are not AMEs or pilots?

Addendum #1

https://generalaviationnews.com/2017/05/18/basicmed-is-creating-conversation/

An update article, after the start of BasicMed.


texts: What kind of container should be used for storing a disassembled Cessna 172?

texts:
I need to store a damaged aircraft away rather than leave it exposed to the weather and elements on a tie-down at an airport. It is a Cessna 172. If I remove the wings and horizontal stabilizer (from the tail), I can fit all lengthwise into a 40 foot shipping container.

However the span of the landing gear is just over 8 feet and won't allow fitting width-wise into a standard container. I suppose the landing gear can also be removed, but not desirable. Are there extra-wide containers suitable for storing small aircraft?


texts: How long would a cruising aircraft take to crash if everyone spontaneously vanished?

texts:
I recently saw a movie in which what appeared to be a Lockheed C-130 Hercules was suddenly without occupants. They did not move or exit the craft, they simply vanished. I assume that the craft remained pressurised, and no modifications to controls were made. I assume that any auto-pilot-like features remained either on or off as they were at the time, unless they have some kind of system to automatically engage in certain situations. At the time of the incident, the aircraft appeared to be cruising.

I am wondering how long it would take for a cruising aircraft take to crash if everyone spontaneously vanished?


texts:
Audio Clip

There is a rwy 24 in this airport. I'm not sure but the aircraft callsign likes 'TBN3BV'. I tried to find what the aircraft type is but I couldn't. Does somebody know what type of aircraft this is?

The aircraft was approaching to land and had number 3. I think there was traffic close to the aircraft. So the controller said make S-turn for safety...is it correct?

I sometimes make L/R360 or 270 to avoid other traffic but, I've never made S-turn while approaching to land.

I want to know what the controller said because I missed some word and I wonder if I can make S-turn while approaching to land. If I could, should I make two half circle?


texts: What are the helicopter frequencies on the LA heli charts used for?

texts:
The LA heli charts list frequencies for the different heli routes in LA:

Are the frequencies used as a "CTAF" for helicopters, or is there an air traffic controller on that frequency telling helicopters what to do? I'm also wondering if the helicopter freq 119.80 at LAX issues class bravo transitions?


texts: Tyre wear and land gear shock reduced by wheel spin up

texts:
From the answer to the question 'How are forces on the landing gear reduced or compensated for at touchdown?' I note:

  "For what it's worth you do not necessarily want to spin up the gear
  before landing for a few reasons. First off you would need to spin up
  the gear to precisely (or at least very close to) the speed that the
  plane was going to touch down at."

And:

  "Spinning the gear up can also have a serious gyroscopic effect that
  will affect the handling of the aircraft."

So why is this not a takeoff problem?

You do not need to spin to landing speed to have a dramatic effect. If you start the spin, you have added angular momentum to the wheel. It is much easier to increase angular momentum in a spinning wheel than it is to instantaneously impart it to a stationary wheel. A few scupper cups on the rim of built into the tyre edge would do the job.

  "This is a great research paper on the topic that suggests (in their
  conclusion) a pre spin situation would see 1.07% of the wear of a
  static situation."

Sounds like a worthwhile saving on so many aircraft.


texts: Why are aircraft tyres not grooved horizontally?

texts: Why are aircraft tyres not grooved horizontally like vehicle tyres? If the tyres are grooved horizontally won't it help in achieving more friction and reduce the chances of veering off?


texts: How much lift is lost by wing dihedral, and can it be fixed?

texts: The loss of lift, though negligible, was mentioned in another thread regarding the angle of dihedral wings. Not knowing the coreect name but will external "ribs" on the wing surface reduce that loss? Also, is that lift loss less or greater with forward swept wings than straight or rear swept? And is that loss due to the dihedral angle of the wings increase with a greater angle?


texts: What is the function of the scissors link in helicopter flight controls?

texts:
What is the function of the scissors link on the rotor of a helicopter?
I assume it has something to do with the flight controls, but I'm not quite sure what.


texts:
Are there any companies that use atom interferometers in aircraft? If so, are they used for navigation? If not, is it possible to assemble it?

Here is the link from wiki Atom interferometer and link from MIT Technology Review of it and a link from a company work on it.


texts: How long does it take to assemble an Airbus A380?


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

texts:
I am a student pilot and just purchased my first sectional chart a couple months ago. While the chart itself is within the effective time frame, there are Aeronautical Chart Bulletins that contain updates to the printed chart. I am supposing that I should notate these changes on my paper chart so I have the most current information, but I am trying to find the best way to do this.

My initial thought was that I could use something like http://vfrmap.com/ to see what those changes look like on an actual chart, and notate them on my chart to match. -But the changes are not reflected on vfrmap, or any other online source that I have found.

Of course I could just create them manually, based on the information listed in the bulletin, but it would be a lot easier to copy them from an existing online chart.

For example, here is the change listed in the bulletin:

But here is the airport on the vfrmap.com:

Maybe I am going overboard here, but I would love some input from more experienced pilots on a practical way to keep my chart current between (6-month) printings.


texts: Are evacuation slides meant to be used as safety boats?

texts:
What are design considerations and usage procedures for these slides in case of some successful water landing?

For instance, are they meant to be detached from the fuselage at some point?

Or instead are they supposed to keep the whole or remaining airframe floating?

Are there any braces or ropes to grab them?


texts: What criteria do FAA VFR Charts use for High-Intensity Obstruction lights?

texts:
FAA’s website provides some symbology explanation (specifically, I’m looking at VFR Charts) and also a database of obstacles, the Digital Obstacle File (DOF). Their PDF provides an explanation of the lighted codes; options of R, D, H, M, S, F, C, W, L, N, U.

I assume that VFR Charts are created with the same data as the DOF. What are the lighting codes in the DOF that correspond to the “High Intensity Obstruction Lights” on VFR Charts?


texts: How does centre of pressure change with angle of attack?

texts: I've been given the distance of centre of pressure from the leading edge with a certain angle of attack and was wondering if it's possible to calculate the new position when the angle of attack changes.


texts: Why isn't there a single best airfoil for subsonic flight?

texts:
Why does airfoil used by modern subsonic aircraft (this is true for transonic airliners too) vary from plane to plane?

Haven't we figured out a single best airfoil shape, with the highest lift to drag ratio?


texts: Official way for tower to address all aircraft on frequency for new ATIS?

texts:
When there's new ATIS info available and the altimiter setting has changed, what's the official phraseology for making the announcement to all the aircraft on the frequency? I'm looking in the FAA ATC phraseology doc FAA order JO 7110.65W, but I don't see it.

My best guess would be something like "Phoenix traffic, information sierra is current, Phoenix altimiter two niner niner eight".


texts: What if there are no volunteers to sit in the emergency exit row?

texts:
I'm currently seated in the emergency exit row, and had an interesting thought. If I was unable or unwilling to assist the crew in an emergency and operate the emergency exit, then I am supposed to contact a flight attendant to be reseated.

But the emergency exit row sucks. The seats don't recline, there's no under-seat storage, there's not even tray tables. What if nobody volunteers to switch seats with me? Will I be rebooked onto a different flight? Or maybe will someone be forced to switch seats with me?

(Let's assume for the purposes of this question that I am physically unable to operate the emergency exit, say because of a broken arm. Let's also assume that the flight is fully booked and there's no empty seat that I could be moved to.)


texts: Is a civilian pilot allowed to fly under part 91 rules with Night Vision Goggles?

texts:
I asked a related question: How hard is it to fly with night vision goggles?

It appears from the answers so far that there are differing opinions, and I guess it might depend on the quality/age/capability of the equipment.

If someone was flying non-commercially (Part 91), Private Pilot (or higher) and it was VFR flight, if the pilot owned a pair of The ANVIS 9, Aviator Night Vision Goggles, Model M949, for example, could they legally fly around with them in their own airplane at night (and be acting as Pilot-In-Command)?

(Assume that they are a safe, prudent aviator, and took efforts to properly train themselves on the equipment and flew with a safety pilot until they were comfortable in the air with the equipment).

Would it be any different if they were flying IFR (appropriately-rated and on an instrument flight plan)?


texts: What is the effect of changing the autobrake setting after touchdown?

texts: If an autobrake setting is chosen prior to touchdown, but after touchdown and nosewheel compression (i.e. after the autobrake has engaged) a different setting is required, is it safe to change the setting during the roll-out? What happens when the setting is changed in this manner? I know application of manual brakes disables the autobrake. Does the autobrake immediately match the new deceleration requested?


texts: Who to contact when inbound to adjoining class deltas?

texts:
Given two class delta airports that share a boundary, say you wanted to transition through one to land at the other.  Who would you call first?  The transitioning controller, or the destination controller?

(skyvector.com)

Example: approaching KOXR from the east for landing through KCMA, VFR w/o flight-following.  Could the KOXR controller clear me through KCMA airspace?  Being conservative, I suppose I could call both but wonder if I'd have time for a frequency change before entering KOXR.


texts: Why the Antonov AN-225 has negative dihedral wings combined with a positive dihedral horizontal stabilizer?

texts: I know the reason why it has negative dihedral wings, but I do not really know why it is combined with a positive dihedral horizontal stabilzer, which are the benefits this configuration provides?


texts: Why is thrust vectoring not used on commercial jets?

texts:
Is there a particular reason for which thrust vectoring is not used in airliners as it is with military aircraft besides weight and complexity factors?

I understand that on military aircraft maneuverability is a core component but, by implementing this technique also on commercial airliners, wouldn't there be any benefit? For example one thing that comes into my mind would be reduction of stress on the tail of an aircraft at high speed/high altitude turns, thus potentially reducing maintenance.

Another option would be increased safety, whereas if maneuverability would be compromised by loss of the tail of the plane (for example American Airlines 587), you would still have some sort of control, even though reduced, on the plane with directional thrust.


texts: Where can I find blueprints for the Wright Model HS?

texts: I'm looking for the Wright Model HS blueprints. Can someone help me?


texts:
I've often flown short flights around the US on aircraft built by non-American companies whose range is less than is required to make a traditional Atlantic crossing.  The Airbus A319-100, for instance, has a range of 2,400 miles while the distance from London to NYC is 3,440 miles.

How do manufacturers get their small planes across oceans?  Do they operate factories in on all continents? Do they fly via Iceland or Greenland?


texts: How do small unmanned fixed wing aircraft protect themselves against lightning strikes?

texts:
I'm asking this question after doing a small research project to see if a small UAS can fly through thunderstorm and trigger lightning strikes. I've googled a bit, and all I've seen are large aircraft getting hardened against strikes.

From what I've read and looked at, all the aircraft use metallic mesh or metal skin to dissipate the heat and voltage. I'm thinking something similar could be done for for a UAS, but don't know how to analyze the system to make sure it can handle the strike.

How does one go about analyzing a structure to see if it can handle lightning strikes? Has anyone flown a fixed wing UAS through a thunderstorm to trigger lightning strikes?


texts: Does the B-1B Lancer have controllable canards?

texts:
These three pictures shows the B-1B Lancer's canards and its elevators. I am not sure to call that feature a canard as the jet also has elevators. In my limited understanding, canard and elevator are substitutes, to use canard or elevator. Then my questions are:

What is that feature's name? Is that canard?
Is that feature (specific to the B-1B) also controllable like elevators?

Picture source 1 and 2: captured from this Youtube video.
Picture source 3: from here.


texts: Why don't airports have weigh stations to prevent overweight takeoffs?

texts: Currently, ensuring that an airplane isn't overweight when it takes off relies on the cargo handlers loading the aircraft properly and accurately documenting (on the weight-and-balance sheet) what with how much weight was placed where, and on the pilots properly reviewing the weight-and-balance sheet once the airplane is loaded.  Even then, there are uncertainties (it is rarely possible to know exactly how much each passenger weighs, for instance).  So why don't airports have weigh stations to weigh the planes as they taxi after being loaded, allowing any flights found to be overweight to be ordered back to the terminal to jettison the excess weight?


texts:
Why do propellors have white markings on their tips?
Here are a couple of examples:


texts: What are the factors considered while placing a propeller on a plane?

texts:
I have read the post where it describes about the push and pull configurations of the engine, advantages/dis-advantages in them but not the purpose.

I have seen images of a figter where the propellers are placed both at the front as well as back, such as the Dornier Do 335.

(Image Source: WikiPedia - Author: Ad Meskens)

Later there are some downsized planes which are remotely controlled vehicles like the MQ-9 Reaper where the propellers are placed at the rear, Miniature UAV have the props in the front (sometimes even the direction of the propeller also vary)

Is it the size which makes the difference or the purpose?

Also what was the scenario due to which the designers had to go in for a varying propellers why not stick to the simple front facing propellers (which are placed either on the wings or in the front why to go for propellers with backward design/rear placed)?


texts: How can an aircraft owner/operator track unauthorized flights?

texts: Is there a product or some other way to track an aircraft's use, even if the pilot doesn't file an IFR flight plan, to let the owner know if it's used without authorization?


texts: Is any endorsement required to take the Advanced Ground Instructor test?

texts:
What, if any, endorsement is required to take the Advanced Ground Instructor (AGI) test? 14 CFR 61.35 does make clear what is required for any knowledge test, but not what is specifically required for the AGI test.

I also noted that 14 CFR 61.193 mentioned that flight instructor privileges include providing an endorsement to take the test.

14 CFR 61.213 also lists several eligibility requirements to become and Advanced Ground Instructor including taking a knowledge test while mentioning no endorsement which is required to actually take the test.


texts:
5:00 am every morning I went to Rice-Field Road for a jog. I always see airplanes with flashing lights. All of them have the same flashing patterns except for the one that I just saw yesterday.

The pattern is a long flash. If I'm not mistaken (I counted it), it flash slowly for more or less 10 seconds and then gone at same count.

I was curious and surprised that there's an aircraft that has that kind of flashing patterns. I gazed at it for a minute until it was out of my sight.

I also found this and I'm not satisfied since I'm more concerned of what type of aircraft was it.

What type of aircraft uses this long flashing pattern? References might also help. Thanks in advance :)

UPDATED:

This was the exact location where I saw it.

I'm not so familiar how high or low an aircraft might be for a landing. But I guess the aircraft was too high for a landing and its direction was straight away from a landing area. And yeah, the flash was color white.


texts: Is there an FAA regulation to switch off the air-conditioning during take off?

texts: The warning above the big white switches in the following picture had me intrigued. Is there some FAA regulation related to the same?


texts: What are Water Vapour Resistant (WVR) engine bags made from?

texts: What specific material are Water Vapour Resistant (WVR) engine bags made from?


texts: Why did the MSA for Taipei (RTCP) change?

texts:
I got a question about the Minimum Sector Altitude (MSA) on Jeppesen arrival plate (RCTP 20-2). The MSA circle  was divided into three sectors with three altitude before (2008, top image), but I found that it is only one altitude (not divided anymore) on the new version.

I've been looking for the reason for a long time but still can't figure it out. Does anyone know why they did such the change?


texts: Why is the B787 one of the few aircraft with electro-thermal wing anti-/de-icing?

texts:
While I was searching for a listing of aircraft with different anti-/de-icing methods - especially for electro-thermal wing anti-ice - I couldn't find any information about other aircraft except the B787.
Is there any reason, why other methods like TKS or using bleed air were prefered in the past?
Are there any studies related to the pro's and con's of the different anti-/de-icing systems?


texts: How do I differentiate between different types of installed wire lock/safety wire on planes?

texts:
Common wire-locking/wire safe-tying materials used in aviation include copper, stainless steel, Monel and Inconel.

Is there any way one can differentiate an installed stainless steel one from an installed Monel or Inconel one? Copper can be differentiated from the rest by its colour.


texts: What are those bumps on top of the Antonov-225? What are they for? And what are they called?


texts: What is the significance of the "date designation expires" on a temporary airman certificate?

texts: I recently received my temporary airman certificate and it says that it expires in 120 days. However, there is a section that says "date designation expires". The date under "date designation expires" is not 120 days. So my question is, does it expire 120 days after the date of issuance or on the date under "date designation expires"? Thanks for any help!


texts: Who checks that pilots have their licenses?

texts:
One weird thing came to my head In the ground, Every time you drive an 91 CRX SIR/Civic Si EM1 or ride an Honda Dirtbike There is an possibility of getting busted by the cops waiting in the temporary checkpoints But what about the air? Who will check (Non existent) licenses of DC-3/Bell 47GH pilots?

Who will check (Non existent) licenses of C208B Grand Caravan Amphibian pilots on the sea? Who will check people that flies alone in a Learjet 35 during IFR conditions? (I know, there are countries that you can do IFR flights alone)

Do you tell your license information to the ATC before the takeoff or there is an another way like authorities requesting flight logs of an C208B etc?


texts: How do uncoordinated turns (skid, slip) affect a helicopter's turn radius?

texts:
Is a helicopter's flight path (track made good) an arc of constant radius regardless if it's a coordinated or uncoordinated turn? (Assume nil wind conditions and that the pilot maintains the angle of bank, altitude and airspeed constant in both cases.)

I'm confused because texts mention slipping and skidding as sliding downhill and skidding uphill from the turn respectively, which to me reads like the radius of the turn changes.

[EDIT] Updated assumptions to include bank angle and airspeed.


texts: Is a lower CHT on one cylinder cause for concern?

texts:
I have some concerns about the level of maintenance and service on some rental airplanes on an out of town trip.
The first airplane I rented had some misgivings, so I went on a different one today. It was a Cessna 172 and had a Cylinder Head Temperature (CHT) monitor, which I hadn't seen before. So while on an extended leg I fiddled with it. Three of the cylinders where 340-350.  However, cylinder 2 was only 280. That seems like a significant outlier.
Since most rental airplanes don't have a CHT monitor, I don't have experience with what is the normal temperature. Should I be concerned that one cylinder isn't close to the other three?
Below is some information about the airplane and that flight:

Power: 2400 RPM
Altitude: 7500 feet
Oil Quantity: 7 quarts
Oil Pressure: Top of green arc
Oil Temperature: Normal

Airplane was fresh out of a 100-hr maintenance
Anomalous Cylinder: #2

There was some issue with the engine during the 100-hr maintenance which held it up, but was signed off by a mechanic with an IA.
I am unsure about the quality of maintenance service there. We had two flights cancelled in a row because the carburetor  was fine when it was warm, but this cold snap (38°F) is making it hard impossible to start. In addition, there are all sorts of small squawks such as trim that was out of whack etc.
The bottom line is that I am concerned about my safety as probably I will be renting one more time. Is the above mentioned scenario something which could indicate a problem, or more likely something harmless? I have doubts that the maintenance is top quality, but I'm unsure if it's bad enough that I should just opt out.


texts: In what scenarios would one want to maximize or minimise rate of climb in an aircraft?

texts:
What are examples of scenarios where a pilot would want to maximise or minimise aircraft rate of climb? What performance metrics should one consider to analyse steady climbing flight?

The scenarios I thought one would maximise rate of climb is military aircraft dog fight and clearance of airspace quickly in airports

Please add your thoughts if you can imagine any


texts: Is there anywhere I can find examples of letters seeking interpretation of FARs, sent to the FAA Office of Chief Counsel?

texts:
Is there anywhere I may find examples of letters seeking interpretation of FARs, sent to the FAA Office of Chief Counsel?

What is the appropriate salutation, if one is needed, on a letter to the FAA Office of Chief Counsel?

Should the actual letter (not the envelope) be sent to the "Chief Counsel" or to the "Office of Chief Counsel"?

Should anything in the way letter is addressed, or who it is addressed to, signal that I specifically am seeking clarification of an FAR and not raising some other legal issue?

Related:

How can someone get clarification from the FAA on the intent of a regulation?

https://www.faa.gov/about/office_org/headquarters_offices/agc/key_officials/media/AGC_Org_Chart.pdf


texts: How does an aircraft report crew programming of the FMS to the ground?

texts:
I am reading in the news that the MH370 flight changed its course by "Computer entry" and that it was programmed into the computer at least 12 minutes before the last voice contact with the plane.

How can they know that the change in the computer was done 12 minutes before (while the plane was still flying as on the original course)? And how do they know it was done in the computer, rather than the pilot steering manually?


texts: What is the effect of flow separation on lift, pressure distribution and drag?

texts:
Consider an airfoil (a wing) in an airflow. When angle of attack increases, at some point the flow start to separate from trailing edge. By increasing the angle of attack more, this separation area increase toward the leading edge up to stall condition which must be avoided. We know that it will cause to reduce the lift and increase the drag suddenly.

But i don't remember what was the exact reason behind this. Whats the magnitude of pressure inside separated regions of flow (wakes)? is it higher or lower than normal flow patterns before separation occur?

I read (for example here) that separation increase 'Pressure Drag' as the pressure inside wakes are lower(?) and we get a more net back force comparing front side and back side of the airfoil:

  In aerodynamics, flow separation can often result in increased drag, particularly pressure drag which is caused by the pressure differential between the front and rear surfaces of the object as it travels through the fluid

But if this is true, then how could we say that this lower pressure in upside of the airfoil decrease the Lift? as the lift is produced from pressure difference of top and bottom of the airfoil.

Note: i can explain the reason using newton third law and change in flow directions. but not sure about exact pressure profiles.


texts: Did turbofan engine explosions become more frequent in last years in commercial aviation?

texts:
There are many incidents with turbofan engine failures during last years. I can list:

2010-11-04 - Qantas_Flight_32
2015-09-08 - British Airways Flight 2276
2016-05-27 - Korean Air Flight 2708
2016-06-27 - Singapore Airlines Flight 368
2016-10-28 - American Airlines Flight 383
2017-09-30 - Air France 66
2018-04-17 - Southwest Airlines Flight 1380

This list is not exhaustive.

Question: did turbofan incidents indeed become more frequent in recent years?

If yes, is there a reason of this suggested?


texts: How does a tiltrotor yaw while in vertical flight?

texts:
Conventional helicopters have a tail rotor or equivalent to counteract rotor torque. The pilot's rudder pedals control the force generated by the tail rotor (e.g. by changing its pitch).

But the V-22 Osprey lacks a tail rotor: it has rudders on its twin vertical stabilisers. Rudders wouldn't seem to have any useful effect when in vertical flight, because there's no horizontal airflow for them to deflect. The AW609 appears to lack even a rudder, in the photographs I've seen: the vertical stabiliser appears to be one piece in a fixed shape.

Co-axial helicopters such as the Ka-50 can yaw by varying the torque of one rotor compared to the other, but it seems unlikely to me that the same mechanism would work well when the two rotors are at opposite ends of the wings. The effect of differential torque would be much smaller, and it would have huge secondary effects (such as adverse roll). For that reason I don't think the Osprey can work that way.

So what mechanism controls the yaw on a tiltrotor?