texts: Can I take position behind a plane for V formation legally?

texts: First, I must find a plane with the same capabilities to fly in its wake. As a pilot, what would I need to locate other planes near me? Or find and weight on a plane going in the direction with equal cruising speeds to follow? Then would there be and issue of just taking position without asking. Should I ask for permission to do so, from the pilot which I'm shadowing or no I need more?


texts: How can a plane fly far longer than designed?

texts:
The current record for longest commercial flight is 21,602.22km by Boeing 777-200LR.

However the designed maximum range for B777-200LR is 15,800 km. So how is this possible?


texts:
The Boeing 787 shares its type rating with the 777, but what exactly does that imply?

Surely it cannot mean any 777 pilot can just jump into a 787 and fly it. While being similar, the 787 has some different systems, most notably bleed-less engines.

I assume it means something like a reduced course to switch to the 787 instead of a full type rating. But then again, Airbus advertises how easy it is to switch between different Airbus aircraft (see "Benefits for Pilots" section in https://www.airbus.com/aircraft/passenger-aircraft/commonality.html), so shouldn't they all share the same type rating then?

So what are the limits for "same type rating"?


texts:
I know that aircraft generate wake turbulence and wingtip vortices, and the strength of those phenomena are related to the size of the aircraft, but how powerful are wingtip vortices in terms a non-pilot would understand?

For example, if a human were standing inside of a wingtip vortex would it have the strength to knock them off their feet?  If the wingtip vortex were turned vertical like a tornado would it be an EF1, or an EF5?


texts: Are carbon fiber/composite aircraft at greater risk from lightning?

texts:
Modern jetliners are protected from lightning by their metal skin. When they are struck by lightning, the electricity almost invariably travels through the skin and out the other side without damaging the internals or passengers.

While carbon fiber is electrically conductive, I have not been able to find any resources with a direct comparison between it and aluminum. This forum post would seem to suggest that it is less conductive, mentioning that

  Although partially conductive, carbon fiber materials, and carbon fiber masts, are regarded as non-conductive (nonmetallic) for the purpose of this technical information report. For lightning protection, carbon fiber masts require the addition of an air terminal and primary conductor as described elsewhere in this technical information report.

Is carbon fiber as electrically conductive as aluminum, and if not, does this pose a problem in the event of a lightning strike?


texts: Why disable stall warning based only on low airspeed, rather than multiple criteria?

texts:
One of the factors that potentially contributed to the Air France 447 crash is that the stall warning was disabled when the airspeed fell below 60 knots.

I understand why this is -- you don't want to have the stall warning go off while the plane is parked at the gate or slowly taxiing.

However, this seems like clearly bad design for two reasons (that should have been obvious to the designers):

This introduces an extra point of failure. If the pitot-static system fails, then the stall warning may be disabled due to erroneously low reported airspeed.
As demonstrated by AF447, a stalled plane may have very low forward airspeed in an extreme stall.

Moreover, it seems like the solution is easy: Only disable the stall warning if a number of criteria are met. For example, the following logic could be used.

  The the stall warning (based on AoA vanes) is disabled if and only if (i) the forward airspeed is below 60 knots AND (ii) the landing gear is down/on the ground AND (iii) the radar altimeter reports a height of 0.

This logic would still prevent erroneous stall warnings on the ground, but it is more unlikely to suppress "real" stall warnings, as it would require multiple systems to fail.

Alternatively, if you are worried about one broken sensor resulting in erroneous stall warnings, you could require only two of the three conditions to hold for the stall warning to be disabled. That's still better than only one condition.

My question: Why do aircraft not use multiple criteria, such as suggested above, for disabling the stall warning?

The point of my question is that you want the stall warning disabled when the plane is on the ground. Whether or not the plane is on the ground should be rather obvious and you should not need to try guessing whether the plane is on the ground based on airspeed alone. There are plenty of other sources of information that can indicate whether the plane is on the ground.


texts: Why is the weather radar mounted on the left wing of the TBM?

texts:
Weather radar is mounted starboard on the Pilatus PC12 or in the Piper Meridian/M600/M500.

It adds drag to the right wing, thus a right yawing moment, and helps to counteract the slipstream effect and P-factor that tends to yaw the aircraft to the left.

So why is the wx-radar mounted port on the TBM ? (the propeller rotates in the same direction as the PC12, so it seems like the wx-radar only adds more yaw to the left)


texts: Is vertical separation based on geometric difference or altimeter difference?

texts:
In the comments below one of the answers to this question about the influence of temperature on vertical separation, the question was raised whether ATC ensure 1000ft vertical separation based on geometric difference (true altitude) or pressure altitude difference.

In cold air, the true vertical separation will be less than 1000ft if the difference in altitude indicated on the altimeter is 1000ft.

Source: the other question

Is there an offical reference that gives the answer?


texts: C-152 carb heat on before landing in hot weather?

texts:
I know the POH for the C-152 explicitly states carb heat should be applied before landing. I fly in a tropical country where temperature is at 30°C on average on the ground, twice the standard temp. Airports I frequent have an elevation at 300' the most. Cruising altitude on most days is between 2500-3500'.

Should I still treat the POH as the bible in this situation, or will the 30°C qualify as an exception?


texts: What are the different wing planforms? What are each's advantages? Where are they commonly used?

texts:
I remember reading that there are four common wing planforms:

Rectangular
Eliptical
Tapered
Sweptback

I'm sure there are more. What are the different types of planform out there?

Each must have its own advantages and disadvantages. What are those?

What's a good example of each?


texts: Why does enriching the mixture ratio beyond stoichiometry give more power?

texts:
In other words, in a piston engine, the best-power mixture is richer than that producing the EGT peak that signals stoichiometric combustion.

Why is that, physically?


texts: What is the difference between a waypoint and a significant point in an airspace?

texts: I know ATS routes are made up of waypoints, but what are Significant Points used for? Is there a difference, or are they really just two names for the same thing?


texts: Why would Emirates fly over Iraq, avoiding Iran?

texts:
For the last few years flying with Emirates from the UK to Dubai, I've noticed it avoids Iraq and fly over Iran to the north. For example, EK40 from BHX to DXB

From Flightradar24

However, flying this month on EK40 I noticed the exact opposite, the flight avoided Iran and flew over Iraq to the south.

I know that the conflict in Iraq has mellowed recently, but that doesn't explain this: the first picture is of EK40 on Feb 7th 2018, while the second picture is of EK40 on Feb 6th 2018.

So, what could be the reason for avoiding Iran so explicitly when the next day the same flight avoids Iraq?

EK 040 on Flightradar24


texts: What are the radio characteristics of communications between tower and aircraft?

texts:
I have a few questions on the types of antenna used for tower-aircraft comms.

What type of antennas are used today for tower-aircraft comms? Are they directional or omni-directional?

What's the range of data rate (in kbps) that these antennas can provide?

Also, is there any safety issues related to power transmission between tower and aircraft? What's the power limit for this transmission? I know that the tower controls the plane until the cruising altitude and after that it hands it over to enroute. Before enroute takes control, how does the tower ensure that the transmit tower is not too high while ensuring it can still reach the plane?


texts: What is the optimum viewing angle to search for something on the ground from the air?

texts:
Continuing my series on our upcoming search for a downed Douglas B-18 bomber in Alaska* (13 more days to go!), I've started to think about the angle we should use to "look down" at the terrain.  This is especially important because I will be mounting go-pro like cameras on the airplane to capture what we "see" on the ground as we go.  I will do this with this handy tie-down mount I came across:

This mount allows the camera's to be positioned at any downward angle.  I wouldn't think that either straight down or straight ahead would be optimum...I would assume a good angle would be somewhere in between.

Obviously this question has some relation to photography, and I may also post this question to Photography.SE.  However, I would also assume there are a great number of pilots and other aviation professionals with experience searching from airplanes/helicopters for things on the ground.

So my question is, what is the best angle (relative to straight ahead) to search for something on the ground?

Keep in mind that I will be searching over glaciers around an active volcano in partially snow covered terrain.

* Related posts:
Where can I find more information about my grandfather's crashed B-18a bomber on Mt. Redoubt Alaska? and
What navigational aid(s) would WWII bomber pilots have used while flying in instrument conditions?


texts: Why are KACV and KTLV depicted differently on sectional charts than KSGU, KBIH, and KTPL, even though each is E2 w/ E4 extensions?

texts:
This question specifically is about non-towered airports surrounded by round circles of E2 airspace, with one or more "extensions" of E4 airspace that abut the E2 airspace.  Therefore it is not the same as the related question that may be noted above.  Also the question noted above is about how certain airspace functions when the tower is open versus closed, not about why it is drawn a certain way on the sectional chart.

Note that this configuration-- a non-towered airport surrounded by a round circle of E2 airspace, with one or more "extensions" of E4 airspace that abut the E2 airspace -- is a somewhat unusual airspace configuration. In the vast majority of cases where a non-towered airport is surrounded by Class-E-to-surface airspace that has one or more rectangular projections, the entire Class-E-to-surface airspace is designated as E2 airspace.  No E4 "extensions" are designated.  Examples: KONP, KSHR.  This question is not about that airspace configuration.

The question:

According to the FAA's "Airspace Designations and Reporting Points" document Order 7400.11C ( https://www.faa.gov/documentLibrary/media/Order/JO_7400.11C.pdf ) , KACV, KTLV, KSGU, KBIH, and KTPL all share the same airspace configuration: a round E2 circle around the airport, with one or more E4 "extensions".

Why then on the aeronautical sectional charts is the Class-E-to-surface airspace near KACV and KTLV depicted differently than the Class-E-to-surface airspace near KSGU, KBIH, and KTPL?

The first two are depicted with a dashed magenta circle going all the way around the airport, while the last three are not.  In the case of the last three the charts give the impression that all the Class-E-to-surface near the airport may be E2, with no E4 "extensions".

KACV: California Redwood Coast Humboldt County near Arcata -- http://vfrmap.com/?type=vfrc&lat=40.978&lon=-124.108&zoom=10

E2 described on page E-127 of the "Airspace Designations and Reporting Points" document, E4 described on page E-211

KTLV South Lake Tahoe --
http://vfrmap.com/?type=vfrc&lat=38.894&lon=-119.995&zoom=10

E2 described on page E-135, E4 described on page E-220

KSGU -- St. George Regional Airport, UT --
http://vfrmap.com/?type=vfrc&lat=37.036&lon=-113.510&zoom=10

E2 described on p. E-84, E4 described on p. E-190

KBIH -- Bishop Airport, Bishop CA --
http://vfrmap.com/?type=vfrc&lat=37.373&lon=-118.364&zoom=10

E2 described on p. E-130, E4 described on p. E-211-212

KTPL -- Temple, Draughon-Miller Central Texas Regional Airport, TX --
http://vfrmap.com/?type=vfrc&lat=31.152&lon=-97.408&zoom=10

E2 described on on p. E-127, E4 described on p. E-209

It seems that it would be good for the chartmakers to standardize on the notation used at KACV and KTLV rather than the notation used at KSGU, KTPL, and KBIH, since there appear to be some functional differences between the E2 and E4 airspaces, as explored in the related question linked below.

Related question with links to additional related content --
What is the primary reason that the non-towered airports KACV and KTLV have E4 extensions to E2 airspace?


texts: What is the exhaust port on the tail of jetliners for?

texts: Jetliners usually have their engines mounted on the wings, so what is the exhaust port on the tail for?


texts:
It seems that there is no XXX IATA code: from Wikipedia, XVL (Vinh Long, Vietnam) is followed by XYA (Yandina, Solomon Islands). There is a source claiming that XXX used to refer to Mena Intermountain Municipal Airport, but from Wikipedia this place seems (rather strangely) to have no IATA code at all (and a source for this claim is given).

What are the reasons for not having the XXX IATA code? Is this a reserved combination? Has it belonged to the Mena Airport in the past, and if so, why has it been deregistered on October 21, 2014, as the source claims?


texts: How does the nose wheel tire stop rotating on retraction as the aircraft takes off?

texts: As we know, the nose wheel tire and main gear tires are rotating when aircraft is taking off and the wheels are retracting. Thus there should be a mechanism to stop this rotation in order to prevent oscillations transmitting to fuselage and damages to wheel well so auto brake system is used in main landing gear brake system to counter this problem. What mechanism used to stop rotation the nose wheel tire? Is it a shoe brake system?


texts: What is the amount of lift produced by friction?

texts:
As Mr. John D. Anderson states, the aerodynamic forces on a body are due to only two sources: pressure distribution over the body and shear stress distribution.

Shear stress is acting tangential to the surface, so to some amount, friction is also contributing to the lift of a body, not only to drag. But what I most of the time see, is that one is looking at the pressure distribution and integrating this over the surface to get the resulting force.

Do we neglect the part of friction lift because it is so little? But for drag we account for it?


texts: What aircraft maintenance logs should I have available for a private checkride?

texts: I’m about to do my Private Pilot Checkride in my own plane. I’ve been trying to find a list of things that will be needed for the Checkride in the logbook, as I had thought it was an updated annual, ELT battery is within time, and all ADs are complied with. My CFI said he thought it needed other things like VOR checks in the last 30 days and transponder checks and more.  Is there a specific part in the FARs or somewhere that lists out exactly what it needed for VFR day/night flight as far as maintenance logs to keep the plane airworthy? I’m not talking ATOMATOFLAMES, but maintenance logs (aircraft, engine, prop) specific?


texts: What information might go in the remarks section of an IFR flight plan?

texts: When filing an IFR flight plan, what information might go in the "Remarks" section?


texts: When do conditions permit doing a controlled fly-by over the runway of a commercial airport?

texts:
A lot of people reading this probably saw Top Gun and remember Maverick performing a fly-by over the deck of the USS Enterprise (in spite of being explicitly ordered not to do so), or saw air shows where aerobatic pilots do all kinds of cool maneuvers for the entertainment of the people on the ground.

What I didn't know was possible is that a commercial aircraft with passengers on board would be allowed to perform such maneuver over an active civilian airport (you can find the video here). The video shows the last approach and landing of a commercial pilot before retirement, in which he's allowed to perform a fly-by over the runway of Jorge Newbery airport in Buenos Aires, Argentina. Throughout the video you can hear other pilots over the radio saluting the pilot who is about to retire, and near the end you can see the passengers applaud and airport and airline personnel on the taxi runway welcoming the aircraft. It's a pretty emotional video even for someone like me who's not related in any way to the aviation community, you should see it if you can spare a couple of minutes.

Anyway, I know that there are certain traditions involved in the last flight of a pilot before retirement but I didn't know that a flyby was one of them. In order obey the rules of this site, the main question I'm asking here is:

What would be the right circumstances where a stunt like this would be allowed?

But I would also like to know if this kind of maneuver has ever been performed on similar circumstances over airports with more traffic or using a bigger aircraft.


texts: Restore air traffic controllers' instructions from aircraft tracks

texts:
Is it possible to understand what commands had been given to an aircraft if you look at its track containing information about lat, lon, altitude, speed and course? Is there anyone who has already tried to do this thing?

What do you think can be a problem? I suppose it may be ambiguous sometimes. For example, heading command and proceed to a fix command can both result in changing heading.


texts: What documented practices are there for NOTAM creators and handlers to combat NOTAM spam?

texts:
Sadly, NOTAM spam is a persistent thorn in the world aviation community's side.  Bureaucratic rump-covering exercises lead to NOTAMs being issued and distributed that are mere noise to the average airman, leaving them pawing through pages and pages of briefing packets looking for a needle in a haystack.

As airmen, we're largely stuck with the results of this all.  While better filtering would indeed be an improvement over what we have now, it would but paper over the underlying problem: the fact that there's this sea of noise to begin with.

How can NOTAM creators and handlers can this spam problem?  Are there documented practices or guidelines they can follow to reduce the amount of rubbish that gets input into AFTN and dutifully delivered to hapless airmen everywhere?


texts: Is it usual for a first officer not to know how to taxi?

texts:
According to this article on afspc.af.mil, the first officer of the 737 the pilot in the story was flying with had never taxied a 737. Is this normal?

The exact quote in the article:

  After landing, the first officer turned to Gongol and asked if he knew
  where to taxi, she had never been to the Omaha airport before. Taken
  aback by how cool, calm and collected the first officer had acted
  without knowing the airport, Gongol remembered landing at the airport
  before pilot training.

  "Surprisingly, taxiing was the most stressful part of the day for the
  first officer," said Gongol. "She had never taxied a 737 before and
  the ATC had no idea that the pilot was the reason for the emergency.
  We had to make a quick decision that her switching to the pilot's seat
  and taxiing the aircraft without the training was necessary to save
  the captain's life."


texts: Can one country really ban another from using its airspace?

texts: Consider the recent restriction by Saudi Arabia on Qatar Airways flights, which prevents Qatar flights from flying over Saudi airspace. Qatar now has to use longer routes and go fly around the land mass. Does the ICAO not prevent Saudi Arabia from this kind of behavior?


texts: Why did my business class seat have a three point shoulder harness?

texts:
I recently rode a short haul international flight on Asiana Airlines AAR111 from KIX to ICN. I was surprised that my business class seat had a three-point shoulder harness given that we’ve discussed many times on this SE why shoulder harnesses aren’t provided to customers.

Interestingly, on the flight back I flew Korean on the same route and KAL [business class] seats don’t have three points, only standard seat belts.

Is there a reason AAR111’s business class has three point harnesses? Why just that plane and not similarly configured other flights?


texts:
Is there a website to find waypoint ID's from coordinate values?

I am looking for waypoints in the Indian ocean area.


texts: ATC calling out regional airlines in traffic advisories: phonetic or "aircraft paint" airline used?

texts:
When ATC points out traffic that is a regional airline (e.g. Compass, Envoy, SkyWest, etc.), do they use the phonetic callsign of the airline, or do they use the callsign of the airline that they are operating as (how the plane is painted)?

The plane that a regional airline flies might be painted differently, depending on which airline they are flying for.

My thinking:

1) Pros of using the "aircraft paint": aircraft who are flying in VMC can spot each other more easily.

2) Pros of using the phonetic callsign: aircraft are on the same frequency in the same phase of flight, so they are more situationally aware if you use their phonetic callsign because they have probably already heard it in another transmission.


texts: Why do the F-22 and F-35 look similar to each other and different from previous designs?

texts: Is there a reason the F-22 and F-35 look very similar other than style, they look very different to F-16s so is there a conscious effort to make them look cool?


texts: VORTAC symbol over KMOT airport - is the small dot the center?

texts: I am looking at KMOT and I see a little dot over the airport symbol, is that the center of the VORTAC?


texts: I've read that modern aircraft don't need spark plugs like conventional aircraft do, as the jet fuel autoignites once it's mixed with the hot air exiting from the compressors. Then why do aircraft like the Airbus A320 still have 2 igniters in the combustion chamber, to ignite the air fuel mixture?


texts:
How high can an airplane be spotted with eyesight? Suppose a plane has a wingspan of 15 m then at what distance it will appear as a faint dot?
What is the correct way to calculate this?


texts:
I need information on the following aspects of flying a small plane.
1). What is involved in a small craft pre-flight inspection?
2). When do you need to, and what is involved in filing a flight plan for a small craft?
3). What things are looked at most closely during a small craft crash investigation? Is there still a 'black box' on a small craft?

Any assistance would be greatly appreciated.


texts: Can someone identify these two Bell helicopters seen in the Czech Republic?

texts:
I would like to ask you for help with identification of two particular airframes.

On Sunday 13 May 2018 around 11.45 local time, I took a picture of two Bell UH-1s south of Brno, Czech Republic. I had only wide lens, so it is not very detailed shot. From what I can see, the heli on the left is very likely Bell 212 (or UH-1N), wearing some colorful paint, maybe in SAR version (it probably has also some sensor ball under nose, or reflector), the heli on the right appears to be Bell 214 wearing military camo or dark paint (green or brown), also with sensor ball. They were flying from east to west, approximately in direction from Slovakia to Germany.

Is anybody here able to help me with as precise identification of these two helicopters as possible: version, operator, tail number...?


texts: Can you operate regular commercial flights from an airport that is uncharted and not in the national AIP?

texts:
Is it possible to operate regular, commercial flights from an airport (aerodrome) that is not in the national AIP, and for which there are no charts, maps, terrain information, obstacle information, NOTAMs etc.?

Here in Mongolia there are 23 airports listed in the AIP (ETOD is already collected and published for free) but there is discussion about removing all of them except Chinggis Khaan International Airport (ZMUB). That means, there would be no information available about those airports. Would they still be usable for flight operations?

(Related to this question.)


texts: Can I include my point of departure in the three landings for my commercial solo cross-country?

texts:
I flew a cross-country with one stop on the way down: A -> B -> C
From A to C is over 250nm in a straight line and over 300nm total.
The next day I flew back: C -> A
That covers the 3 landings at intermediate (B), destination (C) and back at departure (A). But does the landing back at the departure location count as one of the three?


texts: Is there a more specific term than 'flight line' for straight lines flown during flight?

texts:
I work for a small software startup, where its just my boss and I. Prior to this job, I had no experience with aircraft. We have a client that uses our software to fly a pattern over an area, where they fly straight for a while, turn around, and fly back over an adjacent area. They do this so that they can canvas an entire area. I sketched out what this looks like below.

      (start) ---------------------> (turn around)
                                    )
(turn around) <---------------------
             (
              ---------------------> (turn around)
                                    )
(turn around) <---------------------
             (
              ------------>    (and so on)

My boss refers to one of these straight flights as a "flight line". When I looked up the term "flight line" though, I found that it has a few different meanings all related to where the aircraft is parked or serviced on the ground.

So my question: Is there a more correct term than "flight line" that describes the patterns our client flies, which are these sets of straight lines?


texts: How come sonic booms only occur once at the speed of sound and not multiple times?

texts: Fighter aircraft today are capable of flying several times the speed of sound. Why is it that the sonic boom only occurs at the moment the plane crosses Mach 1?


texts: How do rocket engines produce more thrust than aircraft jet engines?

texts:
I can't find the reason why rockets are able to produce so much thrust when compared to turbojets.

I do know that the rockets carry their own own supply of oxygen since there is no oxygen in space or the upper region of our atmosphere. And that the upper stages use hydrogen for longer range.

But given that RP-1 is kerosene basically. A highly refined form of kerosene that is used in jets but kerosene nevertheless. Is there something else that gives the first stage of the rocket it's unbelievable thrust or is it just all down to the RP-1 fuel?


texts: What Makes G1000 NXi Different From G1000?

texts:
The new displays are installed on the brand new Cessna aircraft and upgrade plans are ready.

But what is the difference from the G1000 that was there from the early 2000s? Is the tablet/phone compatibility (Which can be used for charts) what makes it different? I cant find comparisons on the internet.

In short. What makes G1000 NXi better than G1000?


texts: What are the current principles for turbofan nacelle air path design?

texts:
The Wikipedia entry for 'turbofan' states:

  Some high bypass ratio civil turbofans use an extremely low area ratio (less than 1.01), convergent-divergent, nozzle on the bypass...

But the article doesn't give supplemental references or other background apart from working line control. Can anybody give some more information if this is the case for a lot of nacelles being built nowadays or that the majority of turbofan cowls are 'simply' converging ducts and whether or not there is a trend to go to condi-nozzles in the future?


texts: Difference between general visual inspection and pre-flight check inspection

texts:
I know the definition of general visual inspection (GVI) but I cannot understand the differences (if there are) with a pre-flight check inspection.

I am new in the field and I am not a pilot (don't worry...) but I would be glad if anyone could clarify this for me.
Thanks.


texts: If the updated MCAS software needs two AOA sensors, doesn't that introduce a new single point of failure?

texts:
Regarding the 737 MAX story, the New York Times writes:

  "Boeing’s software update would require the system to rely on two
  sensors, rather than just one, and would not be triggered if the
  sensors disagreed by a certain amount, according to the three people.
  Given that the 737 Max has had both sensors already, many pilots and
  safety officials have questioned why the system was designed to rely
  on a single sensor, creating, in effect, one point of failure [emphasis mine]"

Now I understand that this avoids a False Positive, when one erroneous sensor triggers the MCAS.

But, considering the opposite situation, doesn't this update introduce a new single point of failure, a False Negative, when a stall should be counteracted with MCAS but it isn't, because only one sensor detects it?

(Or if not, what am I missing here? Is it that a faulty sensor fails in a certain way and will not read normal AOA erroneously?)


texts:
These new GE9x engines are huge and extremely powerful, but could two of them power a B747–8?

It is possible for some engines to power the original 741s but I am mainly interested in the B748.


texts: What is the effect of uneven ground on ground effect vehicles?

texts:
I understand ground effect as far as Wikipedia explains it. There are two ways to ask my question;

A ground effect vehicle flies along and encounters an obstacle (say a big wave) that's maybe about half the flying height. What will this feel to the craft? My assumption would be a short moment of more lift, which would feel bumpy at best and could damage the craft at worst.
How choppy may the ground be? From the articles about Ekranoplans and similar concepts I read all these vehicles seemed to be designed for inner seas like the Caspian Sea or the Wattenmeer, not for the Pacific. This may be a coincidence or simply wrong. But can we quantify somewhat how seaworthy such a craft would be, or what were the most extreme conditions in which a ground effect vehicle has operated?
When I try to answer the question myself, the one 'killer' condition I can come up with is when the ground rises faster than the craft can gain height (duh). Is this correct, are there others?

I've put this in a list so you can see where my misconceptions might be when addressing the underlying question: the ground in ground effect....


texts: Do airline pilots use this high-speed, high-drag technique for losing altitude?

texts:
This question and another more recent one got me thinking about this.

Years ago on my MEII checkride the DPE showed me a technique for losing altitude on final when the aircraft was high. Typically, I would reduce power, increase drag (flaps, landing gear, etc), hold nose up to lose speed,   and sink like a rock (if necessary slip). However, what he showed me kind of blew my mind. I rarely do it, except when just having fun.

He said, "Do you remember what happens when airspeed doubles?" I said, "Yes, drag quadruples." More precisely the parasite drag quadruples. Drag $= pv^2$, where $p$ is some constant representing parasite drag and $v$ is velocity.

So, we set up high on final, and he dropped the flaps and descended at $v_{FE}$. I was surprised to find that the maneuver used up a lot of the aircraft's energy, and the aircraft was brought down to the glide path and slowed down with plenty of time for a normal landing.

My DPE was a Captain for Southwest back when Southwest was a small airline. My question is whether this is a technique used by airline captains nowadays?

I don't have access to a B737 to try this out, but in a small aircraft like a Cessna 152 you have a $v_{s_{0}}$ of about 35 and $v_{FE}$ of 85.

The idea is you can descend with full flaps at 42.5 knots and power off and it will sink slowly but in a somewhat nose up attitude. Or, you can put the nose down and speed up to 85 knots and quadruple the drag and get on your glide path sooner so that the last bit of the landing is at a proper glide path, attitude, and speed.


texts: We normally hear of wing geometry with dihedral. Most commonly, when speaking of a wing with negative dihedral, we hear the term anhedral. As I recall the prefix "an" indicates "without". On a few rare occasions I have heard knowledgeable aviation people use the terms anhedral for zero up or downward angle and the term "cathedral' for downward  angle (negative dihedral). Which is the correct term for negative dihedral?


texts: Why aren't leading edge root extensions used on airliners?

texts:
Why aren't leading-edge root extensions used on airliners?

Wouldn't they result in shorter wings and smaller slats?

Image source: Wikimedia


texts: How is Calculated TakeOff Time (CTOT) calculated?

texts:
This answer mentions:

  How these CTOT times are calculated is very complex, and deserves
  another question if you are interested.

I'm interested. How does it work? What is the level of complexity involved? What factors must be considered? If possible, what is the complexity class (P, NP, NP-complete, etc) of this problem?


texts: Does the Piper PA-28 Cherokee wing have laminar flow behavior?

texts:
I've heard (and read) that the PA-28 series has a laminar flow wing:

  The Piper had a very thick airfoil that used laminar flow to assure that lift would be lost very slowly up to the stall.

People seem to pitch the Cherokee's wing as some sort of amazing safety and performance improvement. I've always understood that laminar flow wings had an abrupt, harsh stall, but offered reduced drag in cruise. I have a ton of early-Cherokee time on the 'Hershey Bar' wing, and its stall behavior is gentle and predictable, while its cruise speed is almost knot-for-knot on par with a Cessna 172 of comparable power.

Is the PA-28 laminar flow wing just a marketing gimmick? If one were to put a Cherokee wing in a wind tunnel, would we see laminar flow?


texts: What are the slash markings on Gatwick's 08R/26L?

texts:
Google Earth @ 51°08'52.24" N   0°11'35.71" W

The markings are at 100 m intervals, to one side only of the centerline. They're also lighted as seen below.

They are missing from the ICAO aerodrome chart, and are not mentioned in CAP 637 (Visual Aids Handbook).

I measured from each threshold, but the distances to the first in each set don't match. They also don't seem to be new (judging by older satellite imagery).

YouTube


texts: With positive passenger/bag matching rules, what happens to a bag that does not arrive with the passenger?

texts:
According to one answer to Why offload bags for missing passengers when flights are allowed to carry unaccompanied non-PAX air-cargo in holds?, the requirement for Positive Passenger/Bag Matching was introduced in 1988 following Pan Am 103. According to another answer to the same question, airlines cannot accept cargo from the general public.

Yet on a number of occasions when I've flown commercially as a passenger (including once to the US in the summer of 2001), for one reason or another my/our bag(s) have ended up somewhere else, or at the very least, not showed up on the conveyor belt at the destination airport along with the other passengers' bags.

What usually happens at that point is a conversation with an airline representative, and possibly one's card issuer or other travel insurance provider; and the bag arrives a day or two later. For the passenger, that's an inconvenience, but thankfully not usually a disaster.

However, what happens to the bag in the interim in such a situation?

Clearly, the bag very likely wasn't on the same plane as the passenger. This could mean one of two things:

The bag was not loaded onto any airplane (so it's still at the origin airport).
The bag was loaded onto some other airplane (so it's somewhere else).

The case of the bag not being loaded onto an airplane is strange, but doesn't seem to violate the requirements of PPBM; it's just sitting in a cargo holding area somewhere. If the bag was actually loaded onto some other airplane, that would violate PPBM, since there's no passenger on that flight accompanying the bag. (That said, I don't know if it would be possible to exploit this as a security weakness. Probably not, at least not reliably.)

Once the bag is found, it needs to get to where the passenger is now. I can see two basic ways to do that:

The bag is moved by ground vehicle (car, truck, boat, ...).
The bag is moved by airplane.

Driving a potentially long distance potentially just to get a single bag from one location to another seems the less reasonable alternative (it could probably easily cost a significant fraction of the profit from that whole flight), but on the other hand, if the bag is loaded onto an airplane, it definitely is a bag travelling without an accompanying passenger and in this case, it's known as such to the airline, thereby seemingly violating the requirements of PPBM.

If it were to be shipped as cargo, that would presumably qualify as "from the general public".

This seems to me like a "damned if you do, damned if you don't" kind of situation. So what really does happen to the bag, from when passenger and bag are separated, until the two are reunited?

For simplicity's sake, let's assume that what's inside the bag is completely innocous.


texts:
I have trouble understanding why the ball (on the turn & slip indicator) falls into the turn e.g. drop to the left when aircraft is rolled left, when in an uncoordinated turn (slipping turn). What are the forces that goes into this?

From reading up online, many sources quote that in a slipping turn, the aircraft is banked too much for the rate of turn. So, the horizontal lift component is greater than centrifugal force. As a result, the ball drops into the turn since there is less g force to "centralise" the ball.

Isn't centrifugal force suppose to be equal and opposite of the horizontal component of lift. How can being in a slipping turn make the centrifugal force lesser? Essentially, what is so special about slipping turn can allow the centrifugal force to change?

Image from: http://avstop.com/ac/flighttrainghandbook/forcesinturns.html


texts: Is there an aerofoil that gives reasonably good lift for both air flow directions: forward and backward?

texts:
Could an aerofoil be designed to give reasonably good lift for both flow directions?
I was motivated by this related question on Aviation SE: Can a plane fly backward if its propeller is in reverse?
It seems that in practice most wings are indeed optimized for one direction of travel. And that makes sense in the context of the use case they are designed for.
But hypothetically, had a designer to design a wing profile for an aircraft that wanted to be able to fly both ways could it be done? The means of flow reversal could be varied e.g. reversible pitch propellers etc.
Any examples of such profiles?
Why Would You Want To Do This?
I don't have a good answer here. Maybe just curiosity.
More speculation: It could give a fighter or acrobatic aircraft some special manouveres? The ability to reverse without stalling at the end of a steep climb etc.?
Modified Question:
What about an aerofoil that's primarily optimized for forward flow but still has sufficient lift to not perform abyssmally in reverse? i.e. Not strictly symmetric performance. With good lift to drag ratios in forward flight but somewhat draggy in reverse.  Say, a use case where 99% of the flight time is in forward motion but for the other 1% you don't want absolute crap lift in reverse motion.
Perhaps this flexibility can bring out more creativity in the designs?


texts: Are transponder codes 7701 - 7777 ever used?

texts: I understand that blocks of transponder codes are assigned to different area controls. I am curious if the block 7701 to 7777 is in use anywhere? Maybe the emergency code 7700 needs some extra protection?


texts: What is the difference between a wing station and wing buttock line?

texts:
Can someone explain (with images) what the difference between a Wing Station and Wing Buttock Line is, in terms of aircraft structures location identification?

The text I'm reading states:

  W. STA = A plane perpendicular to the wing set at 90 degrees to
  leading edge

  WBL = A plane perpendicular to the wing and parallel to the body
  buttock line

This description has utterly confused me!


texts: Companies that currently manufacture aircraft with center stick controls?

texts: I was wondering if any general aviation manufacturers currently produce center stick control aircraft.  (Not including LSA, Sailplanes, Helicopters). I'm asking about four+ place aircraft other than the diamond da40.


texts: Under EASA rules, what do I need to do to be able to perform aerobatics?

texts:
In addition to the aerobatics mentioned in the title, I would also be interested into formation flying.

Is there a specific licence to be acquired? Does a licence covers both?
What are the requirements?


texts: Does the Flight Data Recorder store the data locally or send it to an offsite backup while in flight?

texts: I was wondering, what a black box actually does ? Does it store the in flight data, in case an accident should occur or it's sending it to an offsite backup while in flight ? And if it stores the data, how huge is it's size, cause I've heard airplanes are known to generate several terabytes of data during a flight.


texts:
I was looking through my ADSB Virtual Radar outputs couple days ago and saw a weird re-route for one of the aircraft that looked out of place.

Can one of the pilots/ATC guys pitch in to help me understand what may have caused this A/C to do this?  Is this "normal"?

I would expect if this was a wake turbulence from A/C ahead they would have just asked the rerouting A/C to just slow down?

Tail #: N39463


texts:
Can planes bank without turning, and if so, how is it possible?
A plane's wing is designed to naturally create lift; the explanation for that is that the greater speed of the air moving over the wing reduces the air pressure above the wing and air pressure from underneath pushes the wing up.
But when the plane is tilted to the left or right relative to Earth's surface and gravity, shouldn't it be "pushed" to the left or right?


texts: Does the flap settings for the best lift/drag ratio change with speed on the Diamond DA20-A?

texts:
As I've recently started time building in DA20, I've noticed the AFM suggests flaps at T/O for a glide. Being very intrigued by this I run across this post. Although I appreciate Peter's reply that does throw some light I'm not quite clear with it and I'd like to elaborate on it further. As the topic is closed, and the forum advises against asking for more clarification, I open a new topic here.

Diamond DA20-A1 FM says:

Climb

Wing Flaps: T/O or UP
Airspeed:   65 kts

further elaborating with a table:

altitude:      0-4000 ft, flaps T/O:  65 kts, flaps UP:  69 kts
altitude:   4000-7000 ft, flaps T/O:  63 kts, flaps UP:  65 kts
altitude:  7000-10000 ft, flaps T/O:  62 kts, flaps UP:  -- kts
altitude: above 10000 ft, flaps T/O:  59 kts, flaps UP:  -- kts

Cruise

Throttle:  as required
Prop. Speed Lever:  1900 - 2400 RPM
Wing Flaps: UP

Gliding

Wing Flaps:  T/O
Airspeed at 1609 lbs (730 kg) (vIAS): 72 kts

I deduce there is a speed below which flaps at T/O create more lift than drag and it is therefore beneficial to have them down, however in the whole ATPL syllabus  I've never run across such a thing - a specific speed at which lift/drag ratio for flaps down changes.

I can understand it's either up or down for the best L/D ratio but I don't get why does it change at a specific speed? Unless the reason is the limitation by Vfe (81 kts) when pilot eventually must retract the flaps even at the cost of lower L/D ratio. If that is the reason, then I don't understand why would someone design a wing that's less efficient to fly in Cruise then in Climb?

So, my final question: does the flap settings for the best lift/drag ratio change with speed, or the wing is not flying at its best efficiency in cruise?

Besides, if we compare climb with gliding speed, we can see that in a climb flaps are to be retracted at 69kts (and even lover as altitude increases), while in glide they are to be at T/O position at 72kts. Where does this difference come from?


texts: What is the low resistance design path in an aircraft to withstand a lightning strike?

texts: I know in a building we have lightning rods that conduct a lightning strike into the earth, but for an aircarft there is no ground to 'ground' so I assume the lightning enters and passes through the aircraft. Therefore, since some areas must have high resistance paths of protection, for example a path through the antennas or main electronics bay, they must be an alternate low resistance path capable of conducting a very high power flow with minimum damage and burning. What is this design path?


texts: If the Quadcopter is a MIMO Nonlinear System, How Can it be Controlled using PID?

texts:
I know that it is very common to control quadcopters using PID algorithms. I'm just wondering if it isn't a problem that the system is highly nonlinear as well as having multiple inputs and outputs. Does the model need to be linearized so that PID algorithms can be used?

Thanks in advance!


texts: What regulations or procedures address runway-taxiway interference for aircraft with large wingspan?

texts:
Are there cases of airports where a large wingspan aircraft on a taxiway can interfere with another aircraft on the runway?

Or do the airport design parameters take care that the largest wingspan aircraft on a taxiway will still never infringe on a runway's safety zone?

How about taxiway-to-taxiway interference? Is that precluded by design itself for worst case combinations or can there be cases where two large wingspan aircraft on two taxiways may interfere?

If so, is it the pilot's duty primarily or the tower's  to ensure that interference does not occur due to conflicting wingspans of aircraft on different taxiways?

Are taxiways with potential for such interference separately indicated on the airport taxi charts?


texts: What is the difference between boomset and headset?

texts:
Both "boomset" and "headset" are terms used e.g. by Airbus:

The audio management system includes:

[...] sockets at each station

headset jack and boomset connector (hand microphone connector) for pilot, copilot and third occupant
headset jack for fourth occupant

[...] boomsets for the pilot, copilot, and third occupant, and three hand microphones (fourth) [...]

(Airbus A320 FCOM - Communications - General - Audio Management System, emphasis mine)
What's the main difference between these two things or are they the same?


texts:
What is that sensor on the Airbus A220?
What is the that sensor in the picture?


texts: Is precession a problem for two-bladed propellers?

texts: The vast majority of wind turbines are a three-bladed design. Although two blades would be more efficient, two-bladed designs are more likely to suffer from precession. Do two-bladed propellers suffer from precession? If not, why would it be a problem for wind turbines, but not aircraft props?


texts: I am a student of a flying school which has 10 Cessna-152's. Since all the aircraft are not equipped with a transponder, there is no way to track them. I am searching for a way to track them like Flightradar24 does with the maps. This is a project assigned for a bunch of students, so we are looking for an inexpensive but still good quality system.


texts: Are there tricks or training to handle spatial disorientation?

texts: For spatial disorientation, are there tricks to block out certain inputs like focusing on what the eyes see and blocking out the ears? I am curious if there are training techniques to practice on the ground to help with spatial disorientation. Do you have any techniques to practice?


texts:
What is the airplane in this video?

(Video is intentionally set to start at 1:27; that is shortly before the first appearance of the airplane in the video.  After 1:50 there are no clear views of the exterior of the airplane, and only extremely limited views of the interior, so there is little need to watch beyond that point, unless you are into the music.  At 2:12-2:15 there is a brief low-resolution shot that includes a good portion of the control panel; nothing of significance after that.)


texts: While waiting for a delayed outbound flight how can I guess where's the inbound plane?

texts:
This summer in Mykonos our flight back to FCO was delayed and nobody at the airport could communicate reliable estimates on when it would be.

In that case I managed to find the FCO-JMK inbound flight on FR24 and saw it left FCO with 2 hours delay, so our own would have been at least that.

In bigger airports with more connections you might not be able to guess which airplane will become yours.

I guess the registration number of the plane assigned to my flight will be available some time (maybe a few hours?) before as per the flight plan.

Is there a reliable public accessible source for that?

When I have the assigned RegNum I can use plane finder, FR24 or whatever to see if it's on its way and have a rough estimate of when it will land and then be available for my flight.

Apologies for my English.

Thank you


texts: What would non-potable water be used for on an airliner?

texts:
Airliners have potable water tanks and distribution systems for galley functions and such; of course, this water is used for any non-potable functions as well as it's what's available on a modern airliner.

However, this question makes me wonder if there are water uses on an airliner that could be served by a separate non-potable water system, or if all the water needed is potable.  If there are non-potable water uses, what would they be?


texts: What is a good plane for aerial photography?

texts:
I'm a bit of a photographer and I keep thinking it would be fun to try and do some shots aloft.  Only trick is, I'm not sure what kind of plane I would want to use to get those pictures done.  I'd have to rent the plane and the pilot and I'd like to keep the price down as best as possible...  So a purpose built plane isn't such a big deal.

Other considerations

Good view of the ground, though it doesn't have to be straight down (I'm not doing surveying
Stable while banking so I can more easily track shots when the plane is at an angle.
Ability to be held stably at a bank without actually turning the craft, again to help me track my shots.
Low vibration, for the same reason as stated over the last two.
Big windows
Can fly low and slow for if I want to get close to things (within reason.)

Also, a high wing is probably preferred.  Though, if it's exceptionally good at holding a bank, it may not matter.

If you think of anything else that I should consider to keep my camera from being jangled about, and to allow me to have a good view so I can get some shots...  Please feel free to leave them in the comments.

So, what plane would work best for this mission?


texts: What effect does tropopause entry have on the FMGC?

texts: In my company it’s a procedure to enter the highest tropopause level into the INIT A page. Could someone please explain the effect it has.


texts: Would it be feasible to use graphene in the gearbox of a large turbofan engine?

texts: What is the possibility or are the drawbacks of substituting graphene for metal in a gearbox of a geared turbofan the size of a Trent 900, given its strength properties(graphene), harder than a diamond, cheaper than a diamond and 10 times the strength of steel?  Previous answers here, on the reasons why large bypass turbofan engines cannot be fitted with gears for efficiency have alluded to torque vs metal gear strength with metal not being strong enough and net energy losses to heat


texts: How can I find our FAA airport designation number?

texts: Several years ago we were issued an airport designation number by the FAA. The information was lost when my father died. How do I find out what our designation number is?


texts: Why is the ILS16 approach at KSKF not available in my Garmin 430W?

texts:
I am doing flight instruction on the San Antonio area (Texas) and I've been shooting different approches on the vecinity airports.
One of the approaches I usually execute is the ILS 16 at KSKF, which is a military and civilian airport. Yes you can land there and do fuel on the self service pump.
Everything was okay until the last garmin database update in which they removed the ILS approach. When you select the approaches on the GPS the only available ones are the RNAV approaches. I looked into the NOTAMs and there is nothing published there, I am still able to request the approach and do it with the VHF Nav Instruments, but was cool for students to monitor what was going on on the GPS as well.
Does anyone know why the approach is not able to be selected on the GPS?
Note: The GPS Database is current


texts: There are many ETOPS certification levels, such as 120 (2 hours), 180 (3 hours), or 300 (5 hours).  However, what is the reason behind ETOPS 207?  Is there anything specific at that point?  Why not make it ETOPS 210 (3.5 hours) altogether?


texts: I've noticed that when a WiFi system is set up on an aircraft, a small bulbous structure is added. What does it contain and how does this WiFi system work?


texts:
Recently, I've been watching a few YouTubers (mostly FOs) who make great videos like this:

Then I realized... They must spend a lot of time setting up cameras, playing with them, hitting record and stop etc. This could potentially distract them or make them miss something (a warning, a pre flight check etc)..

Are they breaking any formal rules doing this? If an accident occurred during filming would they be under investigation due to negligence?


texts: Does a multi-engine rating propagate down from commercial to private?

texts:
I have a private pilot license with airplane single engine land and instrument ratings. I'm about to get the commercial with a airplane multi engine land class rating.

Let's say I'm not currently flying for hire and my second class medical is more than a year old, so I cannot exercise my commercial privileges. Can I then legally fly a multi-engine plane exercising my private privileges, carrying, say, a friend or other non-paying passengers in a part-91 operation?

In other words, does the class-rating propagate down to my private?


texts: What is this device below the door of a 737 (and other aircraft)?

texts: The other day I made a question about the External Power Hatch. Now I would want to know what's that hole below the door.


texts: Relation between lift force and torque produced in propeller used for vertical take-off and landing aircrafts

texts:
There are many answers for this question but none of them are specific.
I need to find the exact relation between the lift force of a propeller of specific pitch, attack angle , dimensions and material with torque to be produced in a propeller at a specific speed at a certain altitude of a vertical take-off and landing aircraft to hover and fly forward.
Can some experts in the field derive this relation.


texts: How has CAD influenced aircraft design in the last few decades?

texts:
I know that computer aided design was used extensively when designing the Boeing 777, are there any other good examples of aircraft where CAD was essential in the design process?

Are there any major leaps forward in aircraft technology that would have been impossible without CAD?


texts: What is the difference between P208 and P209 base runway materials?

texts: Runways are made with P208 base or P209 base does anyone know why there are labeled differently from regular crushed aggregate base? And what the different uses are for?


texts: Is it possible to have two different makes of engine on a single twin-engine aircraft?

texts: Is it possible to have to have two different makes of engines which are generating almost similar thrust for a twin-engine aircraft?


texts: I went to go fly around DFW today, wanted to do some sight see of the city and such. When I got in the air I contacted approach to get VFR flight following and was going to remain outside of the class B airspace anyways for most of it. When requesting to go closer I was told I would need to have an LOA with KDAL (Dallas-Lovefield), which I did not so I remained outside the Bravo, what is an LOA and or how is the best way to be inside the class B for sight seeing?


texts: Is there a relationship between control surface deflection and a particular turn radius or bank angle?

texts:
I am making a project which includes automation of aileron, rudder and elevator deflection.

Is there a quantifiable relation which can tell me the amount of deflection required for any radius of turn if the other parameters are put constants.


texts: What is "detonation" in a piston engine?

texts:
Recently, I saw this question, which included a rather alarming quote:

  Full throttle operation with carburetor heat on can cause detonation.

Woah! That doesn't sound good. In fact, I would have figured aviation engine manufacturers would have worked hard to prevent their engines from exploding, and possibly destroying the rest of the aircraft and/or killing the pilot in the process.

I also found this question, with a rather calm quote:

  What if I have a noise cancelling headset on, and the engine undergoes detonation?

It seems like there should be other cues that your engine just blew itself to bits...

I'm figuring that perhaps "detonation" in this context doesn't actually mean that your engine block turns into shrapnel. I also figure that it doesn't refer to the normal process of piston engines, where fuel is injected and mixed with fuel before detonating. So what does it mean?


texts: Why does the B737NG need electrical power for aircraft towing?

texts:
I have read the AMM for towing and one of the mentioned steps is to supply electrical power. Is it because you need power to turn on the hydraulics in order to pressurize your brakes?

For B737NG


texts: Is there any aircraft that cruises in the transonic regime?

texts: Has there been any airplane that has been able to cruise in both the subsonic and transonic regime where the drag is high because the critical Mach number has been reached or surpassed?


texts: How can you identify the upwind side of a thunderstorm, and why should you fly there?

texts: When flying around a thunderstorm, it is advised that you fly in the upwind portion of the thunderstorm. First off, how do you figure out which side is the upwind and downwind of a thunderstorm? Second, why fly in the upwind?


texts: GPS satellites send data at the rate of 50 bits per second. One GPS subframe is 6 seconds long. How is it possible to update one's position faster than once in 30 seconds when we require the whole frame (5 subframes adding up to 30 seconds) to extract the NavBits for the pseudorange calculation?


texts: What is the way to calculate the required twist of a flying wing?

texts:
I am interested in flying wings and a couple of weeks ago I started researching them. I found mh-aerotools.de website and think it's a great source.

The website stated that flying wings need twist to stabilize, but I don't know how to do this or even is it required at all.

Is a twist needed and if so how do I to calculate it?

Note: I chose airfoil EH 1.0-9.0 for this purpose.


texts: Does the FBW system of a passenger aircraft use differential thrust for yawing?

texts:
Are there situations where the fly-by-wire system of a commercial passenger aircraft will use differential thrust to yaw? Or is that even possible at all (i.e. do the necessary interfaces exist)?

I imagine it could for instance be useful in the case of a crosswing landing, to maintain full yawing capabilities. Also, I guess the connection between flight controls and the engine control system exists, as it is shown for example by the envelope protection of an Airbus.


texts: Does aircraft nacelle length/shape/geometry affect the contrail formation?

texts:
This is coming from Question 1 and further down Question 2.
I think the nacelle and exhaust cone do affect the contrail formation in some way, what is the relationship between them? Do the famous 787 Chevrons also affect the contrails? And How does it  compare with engines with exhaust mixer?


texts:
What is a line replaceable unit (LRU) in an aircraft data bus system?

What kind of components are defined as LRU in a data bus system?


texts: What does it mean when ATC says "altitude indicates"?

texts:
I've noticed that ATC sometimes calls out traffic (a traffic advisory?) to aircraft using the "altitude indicates" phraseology, and sometimes a specific altitude is given without the phrase "altitude indicates".

Is there a specific reason for when they use one over the other?


texts: Could a blown wing ever be powerful enough to lift an aircraft at zero forward velocity?

texts:
Theoretically, could an aircraft, using any manner of self generated air flow over the (fixed) wing, ever gain enough lift in order to take off (or just simply lift off the ground) at zero forward velocity?

I am guessing that if an aircraft and its engines were light enough, you might be able to provide a high enough airflow across the wings using the propellers (akin to forward motion) - although obviously I am fully aware that most of the important control surfaces would not be functional. This is just theoretical.

To what end.. well... a more efficient understanding of self-generated lift (possibly?) might result from research into extreme blown flap/wing super-STOL utilization. High-lift, small transport aircraft operating out of small congested city air/heliports with very small runways.

I am aware of the limitations of such designs, such as inefficiency at higher speeds and, in the absence of variable form and geometry (which would add too much weight) the fuel usage would become prohibitive. It's purely an idea for speculation.


texts: Can an airline order a 777 with 787 flight deck avionics?

texts: So an airline orders a 777, but instead of the cockpit in that, they request the 787 cockpit installed in their 777, is this even doable?


texts: Do any aircraft windshields have anti-reflective coatings?

texts:
Anti-reflective coatings are used in many applications to reduce glare and prevent double images.  Double images in particular are a concern because of the several layers involved in a cockpit window.  More high-tech optical coatings can also have other desirable properties such as reducing UV and IR light transmission. There is some evidence of them being used in industry, like this patent for a windscreen. On a related note, cockpit instruments have a limit for maximum reflectivity of their glass/plastic surface and sometimes use anti-reflective coatings.

I started thinking about this because of a recent question on why windscreens aren't more reflective.

However, I can't find many examples of anti-reflective coatings (possibly because of the harsh environmental conditions?).  UV and IR protection seem to be mostly through tinting instead of coating.

Do any production aircraft use anti-reflective or other coatings?  Why or why not?


texts: Is this Corrected Mass Flow equation correct?

texts:
I have an engine air mass flow rate (322 kg/s) which I would like to convert to a corrected mass flow rate at 10000 feet.

I have tried using the equation found here. However, this article lacks any sources and I have struggled to find any other reliable sources online.

I have made an attempt using the equation in the article but have gotten a greater mass flow than 322, which doesn't make sense.

Is the equation in the article correct or am I just calculating this wrong?

For 10000 ft I get:

Temperature 268K
Pressure 69.6817 KPa

So
Theta = 0.9301 and Delta = 0.6877

Which gives a corrected mass flow of 451 kg/s.


texts: Can Transition Altitude (TA) and Transition Level (TL) be equal?

texts: In Europe, is it possible that Transition Altitude and Transition Level are equal, that is, TA=8000 ft and TL=FL080? In that scenario, at 8000 feet, what pressure (QNH or QNE) should be set in the altimeter? Is it possible that Transition Altitude is higher than Transition Level, e.g. TA=10,000 ft and TL= FL090? If the above scenarios are not possible, is there some minimum altitude of the transition layer that must always be assured?


texts: I was flying the other day by a military base and heard a military aircraft (I'm not sure what type it was) request a tactical penetration descent from the controller at a civilian airport. What is a tactical penetration descent?


texts: Do older aircraft require increased general maintenance?

texts:
Does the age of the aircraft increase the aircraft's maintenance expenses, fuel consumption, and electrical shorts?
If so, by how much?
And is this a reason why planes get scrapped?


texts: What is the loud noise of a helicopter when the rotors are not yet moving?

texts:
What is the loud noise when a helicopter is ready to start flying, but the rotor is not yet rotating?

For example at Trump's "chopper talk", when he is intercepted by reporters on the way to Marine One? The helicopter nearby makes really loud noise already, which makes it hard to communicate between reporters an Trump - so it seems to be something important. It's not the rotor itself, as it's not rotating.


texts: Why doesn’t runway 31R at JFK have a VGSI?

texts:
All of the runways at JFK have a PAPI except 31R.

Why does 31R not have any kind of VGSI?


texts: Why didn’t the space shuttle have flight control manual-reversion capability?

texts:
The Wikipedia article on STS-1 (the first orbital space shuttle mission), in a discussion of all the problems and malfunctions occurring during the mission, mentions that, due to an unexpected shockwave during booster ignition, Columbia’s rear bodyflap (part of its pitch control system) was (unbeknownst at the time to either Mission Control or the crew) bent upwards beyond the point where damage to the shuttle’s hydraulic systems would have been expected.

According to the article, had Columbia’s hydraulic lines actually been breached, resulting in a total loss of hydraulic fluid, this would have rendered the shuttle uncontrollable as soon as the aerodynamic forces on the orbiter during reentry exceeded the control authority of its reaction-control system.

Small- to medium-sized aircraft with hydraulically-actuated flight controls essentially always have some form of manual reversion capability in case a no-hydraulics situation occurs, where the primary flight control surfaces (always the elevator and ailerons, and sometimes the rudder as well) are operated manually by the pilots, usually by control cables attached to the pilots’ yokes and pulling (depending on the aircraft) either on the control surfaces directly or on servo tabs which then generate aerodynamic forces which move the control surfaces.  (Large aircraft generally don’t, even though even partial control authority would still be better than nothing, but that’s another question.)

To the best of my knowledge, the largest Western aircraft to have flight controls with manual-reversion capability is the Boeing 737 MAX,1 which has provisions for full manual control of the ailerons and elevator, plus a small amount of undocumented manual rudder control (as the rudder is rarely or never used during normal flight, manual rudder control is far less critical to have than manual elevator and aileron control, and using a manual aileron-and-elevator system rather than a manual three-axis system allows for a simpler system; however, due to the design of the 737’s rudder system, the rudder can nevertheless be manually moved slightly by a sufficiently large amount of force on the rudder pedals).  The 737 MAX is considerably larger than a shuttle orbiter, with a maximum weight of 88,300 kg, as compared to the shuttle’s empty weight (as its flight control capability, or lack thereof, would only be relevant during descent, when it would generally be empty, and, therefore, at its lightest) of 68,600 kg; even with the shuttle orbiter at its maximum allowable weight (to allow for the possibility of a hydraulic failure during an abort scenario while carrying the absolute heaviest possible payload) of 109,000 kg, it would be less than a quarter again the size of a 737 MAX 9, which would seem to indicate that including manual-reversion capability for the shuttle’s flight controls would have been doable.

Why, therefore, wasn’t it included?

1 The Ilyushin Il-62 is almost twice as heavy as the 737 MAX 8, with an MTOW of 165,000 kg, and has a fully mechanical flight control system (no hydraulics even in normal operation); however, it was a Soviet aircraft, making it somewhat unlikely that the space shuttle design teams could have gotten access to its technical data (especially given the heavy involvement of the U.S. Air Force in the design and development of the shuttle - for instance, the shuttle would have had much smaller wings were it not for the design requirement to launch into a polar orbit to either deploy a U.S. spy satellite or kidnap a Soviet one, and then reenter and land after just one orbit, with the consequent large crossrange requirements).


texts: Would the benign spiral maneuver be one alternative to dealing with being "stuck above" or inside a cloud?

texts:
Recently I provided an alternate answer to a question involving "hands off" recovery techniques.  In this I briefly illustrated the benign spiral maneuver.  For completeness I will reiterate what I said in that answer:

This (benign spiral) maneuver is considered to be the safest way of recovering in a glider when one has found themselves above a hole-free cloud layer or inside a cloud.  My club teaches this maneuver as part of initial glider pilot training, though it is not (yet) part of the US FAA Glider Practical Test Standards.

The steps my club recommends are:

Full spoilers
Trim slightly aft (Other references suggest 1.5 times the stall speed)
Hands off stick
Feet off rudders

The effect of this maneuver is the glider will settle into a gentle spiral with a roughly constant (and not load-exceeding) airspeed and altitude loss.  The maneuver is also taking advantage of the aerodynamic stability mentioned in other answers which is inherent in most (all?) modern gliders.

Here are some additional sources that discuss this maneuver:

Scottish Gliding Centre's Airfield Procedures, Page 17 - 18
This post, which quotes "Transition to Gliders, A Flight Training Handbook for Power Pilots" by Thomas L. Knauff.

That got me to thinking about whether this technique would be applicable to recovery from the same situation in a powered airplane.  Being "stuck above" or even inside a cloud has certainly been the cause of accidents.  One harrowing story that really hit home for me is told in this video from the Air safety institute.

So, my question: Would a benign spiral be one alternative to dealing with being "stuck above" or inside a cloud?  Lets assume for the sake of argument that the airplane involved is a typical single-engine, forward prop GA aircraft (e.g. Cessna 172, Piper Cherokee, etc.)


texts: If pilots in a A320 or 737 had a dual engine failure, would they add flaps for the landing?

texts: Would this not be smart to do because you may come in a little fast, therefore the flaps would send you back up? Or would you absolutely want flaps in this situation


texts: The stall angle  of a wing in ground effect reduces in comparison to the stall angle of a wing flying outside of ground effect. Doesn't this make soft field takeoff dangerous?


texts: What are the requirements to get your private pilot certificate?

texts:
I am 15 right now and I want to get the Certificate/License when i am 17. (17 is the age right?)

How much training do I need and is there any written tests etc?

What kind of IFR training will be included/needed?


texts: Why is a contra-rotating High Pressure section more efficient?

texts: In the Rolls Royce Trent 900 marketing material, the use of contra-rotating HP system is described as increasing the efficiency of the engine. Can anyone explain why/how that increases the efficiency?


texts: Rolling take off compared to take off from a standstill

texts: When ever I fly I choose flights with the most take off and landings. After going down the taxiway and turning onto the runway sometimes the flight crew ramp up the engines up while holding the airplane from moving with the brakes, then let off the brakes and the plane shoots down the runway like a rocket sled on on wheels. Other times the plane will go down the taxiway, turn onto the runway and without stopping ramp up the engines and head down the runway. What is the difference in these two techniques? Is it pilot choice?


texts: What is the standard temperature used in this true altitude equation?

texts:
The control tower of a certain airport with true altitude of 2000ft informs the pilot that QNH is 900hPa and the temperature at the airport is -10 degrees Celsius. The airplane is at FL300 (vertically above the airport) and the OAT measured by the airplane sensor is -30 degrees Celsius. What's the true altitude of the airplane?

The teacher gave us the following formula

$$Z_v=Z_{QNH}+(Z_{QNH}-Z_t)\frac{4(T_v-T_{Std})}{1000}$$

but the question is. We have the $Z_t$ (2000ft) and $T_v$ (-30 degrees Celsius), we can calculate the $Z_{QNH}$, but what is the $T_{Std}$ ? Is it the temperature at the flight level considering the ISA Atmosphere or do we need to start with -10 degrees Celsius and calculate the temperature at FL300?


texts: What are the margins used to avoid a stall while slipping near the ground?

texts:
Similar questions have been asked before, but in life-and-death questions like this, I want to be certain. This question is about airplane behavior close to the ground in normal and/or near slow flight.

I know that based on the angle of attack, a stall can occur at any airspeed. Alas, what should/does the IAS measure?  Presumably, it is from a pitot tube extending from the wing, straight into the relevant wind that is to fly over the wing, so if the angle of attack becomes very high, presumably the IAS dives, too.

For a small 2-seater or 4-seater with a modern wing (like a Diamond or Cirrus or Flight Design), is an indicated airspeed of 10 knots above stall speed a sufficient guarantor for not stalling?

For example, in a slip near the ground, if my configured stall speed is 60, and I fly it so that my IAS steadily drops down to 70 in my uncoordinated slip (at which point I relax back pressure to keep IAS at 70), am I then assured that the airplane cannot enter a stall?


texts: Does an heavy propeller aircraft (CS-25) have the Blu Line (Vyse) displayed on ASI?

texts:
Does a propeller aircraft that is categorized as CS-25 (EASA Regulation) have the Blue Line (Vyse) mandatory displyed on ASI?
I know that would be the case for lighter aircraft (Less than 19000 lbs /8600kg), but my question is related for heavy aircraft (Dash8 example).


texts: Who makes the call to start in terrible weather conditions?

texts:
I once headed to the airport during a huge thunderstorm with winds above 55 knots and massive rain and some small hail. At the airport, I saw that most flights were delayed or even canceled. To my surprise, my flight was still planned to depart on time. At the counter, I got the information that it was up to the pilots to make the decision if they want to delay or if they what to depart during the storm.

My flight was only a short hop of about 50 minutes and given the direction of the storm it was pretty clear that the storm would reach the destination at the time of the scheduled arrival. And this is exactly what happened. It was the most turbulent, terrifying and scary flight I ever had.

In the last two days, there was another windstorm in Europe with winds above 60kts. The news reported that some airports were closed but there are also videos on Youtube about planes landing during that storm.

My question is: Is it really only up to the pilot to make this decision? Who else might make that call? The airline? The airport? Are there official rules about departing in such conditions?


texts: How do I fill the PBN\ part in a Flight Plan Form?

texts:
Flight Plan Form Section 10 is the "Equipment" section, where one input whatever navigation or communication equipment on board. In addition, Section 18 is the "Other information" section, where you can add any supplemental information, some of it in relation to the aforementioned "Equipment" section.

My aircraft has every RNAV\RNP capabilities with indicators 1 through 10 (RNAV/RNP 10, RNAV 5, RNP 4, RNAV 2, RNAV/RNP 1). I need to use the "PBN\" indicator to detail PBN equipment capabilities. My question is how exactly?

In my case, should I file PBN\A1B2B4C2D2L1O2S1? Is it over the character limit? Is it actually necessary? Does it make sense?


texts: What protection did the Concorde have against an uncontrolled decompression?

texts:
The Concorde's cruising altitude was 60,000 ft. I believe if the cabin ruptured at this altitude, everyone onboard would be almost instantly killed, if not from the Armstrong limit then from hypoxia (as oxygen masks cannot supply sufficient oxygen at that altitude).

Therefore, there should have been extra protection against cabin decompression in the Concorde. This type of accident would have probably caused an immediate stop to the Concorde program.

What safeguards did the Concorde have against an uncontrolled decompression?


texts: Can the back tail of an airplane move the neutral point backwards?

texts: I'm currently in the process of designing a prototype aircraft and since I don't have very much experience with this I have the following question: I know that the center of gravity of an airplane should be located in front of the neutral point (aerodynamic center) so it is self stabilizing. The problem with my design is that the main wings have to be in front of the center of gravity. To counteract that, can I design the back wings in a way so that the neutral point is moved behind the CoG?


texts: How far could the Wright brother's catapult have thrown their unpowered plane?

texts:
I know that the Wright brothers started to use a catapult in September 1904 to help their Flyer II take off easily even when no headwind was available.

Assuming the propellers did not turn, or they were not even mounted on their shafts, how far away the catapult could have thrown Flyer II together with its engine and pilot? 1m, 5m, 10m, 25m, 100m or more? Even a rough evaluation, based for example on an experiment with a scale model, would be good for me.

(Note: I am not interested in a pure ballistic evaluation, considering the plane the equivalent of canon ball of mass, m, that is accelerated to the speed, v, and launched at an angle alpha.)


texts:
I would be interested in learning more about Flight Data Monitoring  in order to build data analysis tools.

The most basic question I have, is whether Flight data is recorded using a standard format. If yes, where could I find additional information about this, including sample data


texts: Calculate G-Load of a Rocket with Thrust Vector Control

texts:
maybe someone of you can help me: I have a rocket which uses rudders as well as a thrust vector control system to do maneuvering.

My question is, how can I calculate now the maximum possible g-load which I can use to do maneuvering?

To my mind, the maximum possible g-load is more or less independent of the thrust vector force as well as the rudder force. It nearly depends only on the lift, generated by the wing. This lift has to balance the thrust vector control and the rudder (both pushing the back of my rocket downwards (like in the picture)) as well as the weight. Thus, maximum generated lift determines my maximum possible g-load (Lift / Weight).

But in any way, my thrust control system is responsible in "how fast" my rocket can spin about it's centre of gravity. So if the thrust pushes the aft downwards, it is turning faster than without because the thrust system creates a moment (when not in line with the flight direction). This way I can do a faster maneuver than without a thrust control system. And g-load and turning rate do depend on each other in any way as well.
So I think: the higher the thrust vector -- > the faster it CAN spin around it's center of gravity. But nontheless, we still need the lift of the wings, which must balance the thrust and weight. So only the lift is responsible for my maneuvering?

Thanks for your ideas
Lucas


texts: Why can't I exactly match the same points on different VFR sectional charts?

texts:
I am taking a trip from somewhere on the Phoenix sectional up to the grand canyon.  I wanted to just splice the two sectionals together on my computer and then print them out.

I picked a coordinate to align (as you can see in the first image), and with that coordinate aligned, almost nothing else on the map matched up.

Why aren't the sectional maps standardized to people can do this more easily?  I would have loved to make a "custom" map out of the Phoenix sectional, Vegas sectional, and Grand Canyon map, but it's virtually impossible without modifying them further, which I don't want to do in case of messing up the scale and/or orientation.


texts: Are there cases where a double horizontal stabilizer is useful?

texts:
I was watching Agents of Shield recently, and in it the team fly a plane that's claimed to be a modified C-17 Globemaster. It has two extra engines, rotary turrets, and, according to the wiki, a pair of half-length wings at the rear of the fuselage, seen here:

(image courtesy of Agents of SHIELD wiki)

To me, it also kind of looks like a second horizontal stabilizer. Certainly some of the modifications to this fictional plane are pure flights of fancy, but is there any basis behind this one? Is there any reason why this feature would be useful? Have there possibly been any experimental or production aircraft with something like this? Or is this pure "cool factor," with no real basis in aviation?


texts: What is the requirement to become a flight attendant?

texts:
We know that flight attendants, on top of serving passengers (which is what they do 99% of the time), are there to ensure the safety of passengers on board. For example, they are trained to operate emergency equipment in the event it is necessary.

What is the legal requirement to become a flight attendant? I am not asking how one can get hired (which may involve speaking different languages, being friendly to customers etc.), but how one can serve as a flight attendant on a commercial flight recognized by aviation authority.


texts: What happened to the Boeing Y3 aircraft? Did they ever produce a fully functional prototype? What is the likelihood that it will ever be produced, and when will they start production?


texts: Is the KC-135 landing gear life limited?

texts: I'm looking for information about the KC-135 landing gear. Specifically I want to know if its life limited and if so where is it documented? If its NOT life limited where is that documented? I'm talking about gear that has regularly been maintained or gear that's been overhauled. I've been looking on the internet and a variety of 135 manuals.


texts:
According to this press release by Boeing earlier this year, the 747-8 has received its ETOPS 330 rating. This is required by all 4-engined planes made after February 2015 to fly beyond 180 minutes from an en-route alternate airport.

Does this apply only when one engine has already failed? I understand four-engine jets usually continue to their destination on three engines. And how does this compare to the 747-400. Can it fly ETOPS 330+ routes? I remember them doing missions that twin-engine aircraft couldn't because of their lack of ETOPS.

A follow-up question for those who are interested: Why does ETOPS not apply to older 4 engine aircraft?


texts: If indicated air speed does not change can the amount of lift change?

texts:
A friend and I were having a discussion. He says that if you are flying in a 50 knot headwind and the wind suddenly stops, the airplane will lose lift.

I say that this will not result in a loss of lift because, although the ground speed will change, the indicated airspeed does not change and no lift will be lost.

He then brought up microbursts and wind shear as an example of wind direction changing causing a change in lift, however I am not so sure. I think in those examples it is actual downdrafts pushing the plane down or the movement of air over the wing in a non-coordinated way, similar to how the air in a slip does not pass over the wing in a way that generates the most lift.

Does anyone have an answer? If an airplane is in a 50 knot headwind and the wind suddenly stops, will the airplane lose lift? What is the actual cause for loss of lift in a microburst or in wind shear?


texts: What is the process to contest a local FAA (FSDO) policy which appears to contradict their guidance?

texts:
As the title asks, what is the formal process to contest a local FSDO policy which appears to contradict a FAR or FSIMS (8900.1) guidance?

I have already sent an email asking them to reconsider, to which the inspector reviewed the request with his front line manager and said that they were not going to change it (in spite of what I feel is clear guidance to the contrary).

I then asked for the policy to be reviewed by the local FSDO manager who would be in a position to change it, who also said that the policy would not be changed.

What is the next step?  Elevate it to regional/national?  I remember reading about a formal process where you make a request, and if it gets denied you have 30 days in which to ask for it to be elevated to the next level, but I don't know where I saw that.


texts: Topics for high school chemistry project (IB Chemistry IA)?

texts:
I have to do an IB Chemistry IA and I wanted to relate it somehow to aviation; however, I can't do anything super complicated though because I'm only a high schooler. Here are some possible topics along with research questions...

Fuels - comparing qualities, response to different variables/environments
Aluminum alloys - strength testing, response to different weather, idk
Antifreeze - how it works, how to strengthen, etc
Paint - UV radiation corrosion, high temperatures

This list could go on and on, but I'm curious what you all think is a good idea. All a topic really needs is just a chemical reaction(s) that can be extensively studied and extended. Also it's important to note I don't actually have to do any experimentation, I just have to find information online in papers and databases. Sorry if these ideas sound ridiculous/outlandish, this is my first time attempting to tackle aviation from a scientific perspective. Thanks for any help.


texts: How do pilots cope with pressurization changes?

texts:
I have tried

drinking a glass of water
yawning
plugging my nostrils and pushing air

but none of these seem to work - I still have a distinct pain in my upper sinus cavities when changing pressure in an airplane. I have the same pain underwater.

Do some pilots have this problem, and do they have a remedy?


texts: Static ports open directly to the outside of fuselage. When aircraft is flying, there will be air flowing outside of static port. How does this not cause a vacuum effect inside the static port. Due to the Bernoulli Effect, as the speed of air flowing outside of fuselage increases, the pressure inside static port should decrease. This means, on same altitude, depending on my aircrafts speed, I will read different values on my altimeter. What prevents this ?


texts: Why is LGA's Instrument Approach Procedure VOR-H misaligned with the runway?

texts: I was looking at LGA's Instrument Approach Procedures, and I noticed that on this IAP plate the final segment (CHUGG to MAFAS) is misaligned with the runway. How should I interpret this? Shouldn't be aligned with the runway, in order for the aircraft to be able to land?


texts: Can I convert an FAA medical certificate to a Canadian one without visiting an AME?

texts:
I currently hold a first class FAA medical certificate. Can I transfer to a Canadian medical certificate without meeting with a Canadian AME?

  (2) The applicant may obtain a TCCA Medical Certificate as follows:

  (i) The applicant may submit either the original or certified copies
  of FAA medical examination reports directly to the Civil Aviation
  Medicine Branch of Transport Canada, Headquarters in Ottawa for
  processing and assessment;

or

  (ii) Applicants may complete an aviation medical examination by a
  person who is considered to be a medical examiner with the authority
  to conduct aviation medical examinations pursuant to CAR 404.16


texts: What are the minimum hours required for private instrument fixed-wing plus commercial helicopter?

texts:
I want to get my private pilot plus instrument rating in fixed-wing aircraft for personal use. In addition to that I want to get my private and commercial in helicopters to start a career in flying helicopters.

Does my flight time accumulated in both fixed wing and rotorcraft count towards my commercial rating? As in: 40 hours fixed private, then 40 hours fixed instrument. Then 30 hours helicopter private and 30 more hours for the commercial rating? That would come out to a total of 140 hours. All I would have to have would be 10 additional hours of flight time to qualify for my commercial.

I get that not everyone finishes in the minimum hours on everything, but that aside, am I reading the rules correctly? Or would it be 150 hours in helicopters only?


texts: What are the visual differences between the F/A-18 Hornet/Super Hornet and the EA-18G Growler?

texts: I was looking at the Northrop Grumman website and came across the EA-18G Growler, which looks very similar to the F/A-18. What are the visual differences between the two?


texts:
What exactly are upwash, downwash and propwash? My understanding is:

Upwash is the fluid (air) that initially flows over the wing
Downwash is the fluid going down the wing
Propwash is a byproduct of the thrust created by the propeller, and you would experience it ahead of the propeller

Is that correct?


texts: Can a CFM56-3C engine be converted into a CFM56-3B1?

texts: Is it possible to take a CFM56-3C engine and modify it to a CFM56-3B1 engine? I own a CFM56-3C engine but my customer would like to install a CFM56-3B1 engine on his plane. Can this be done?


texts: What would happen if a Russian TU-95 had an engine failure or other emergency close to the United States?

texts:
Russians often fly the Tu-95 for long distances, in some cases reaching the California coast.

What would happen if they had an engine failure or another emergency Considering the aircraft's age, an emergency is not a very remote possibility.

Would the Tu-95 land in California?
Would it rather try to come back home on 3 engines?


texts: Is ATC clearance or permission required to fly helicopter routes and transitions in the Los Angeles area?

texts:
Skyvector has Los Angeles helicopter charts here and here.

Are pilots required to obtain ATC clearance or permission to fly helicopter routes and transitions?


texts: Why don't all pilots receive at least basic instrument training?

texts: Given the frequency with which non-instrument-rated pilots get themselves killed attempting to continue VFR flights into instrument conditions, why don't all pilots receive at least basic instrument training (at the very least, knowing how to interpret the navball and headingometer) during their initial flight training?


texts: What is this twin engine propeller aircraft flying for Garuda airlines in Indonesia in 1983?

texts:
Twin propeller small civil aircraft flown by Garuda Airlines Indonesia in 1983.

aZxGQ.jpg


texts: How to get the true altitude in non-standard temperature using a regular barometric altimeter?

texts: I wondering how can we get the true altitude with non standard temperature on regular barometer altimeter, as we know that if we set Kollsman window to the current local setting the altimeter SHOULD shows the actual altitude above sea level ( True Altitude ), but if the temperature is above or below standard the indicated altitude on the altimeter will not be the same as the actual true altitude.


texts: Why do airplanes use MAYDAY when in danger but ships send SOS?

texts:
I thought SOS means "save our souls",  but apparently it doesn't.

But ships send SOS when in danger and they used Morse code.  Why do airplanes use MAYDAY?


texts: How can we calculate the fuel that we need?

texts: Let's assume that we are crossing the Atlantic (about 3,878 miles) with a 737-8 MAX. How can we calculate the fuel that we will use during our flight?


texts: How to transform a NACA airfoil into a near-circle using the inverse Karman-Trefftz?

texts:
Is there anyway to find the leading-edge's center of curvature of a NACA Airfoil?

I'm trying to transform a NACA airfoil into a near-circle using the inverse Karman-Trefftz transformation. the transformation has 2 singularity points, s1 which is located on the trailing edge, and s0 is located midway between the leading edge nose and its center of curvature.. now for symmetrical airfoils it's easy to find s0, since the center of curvature is on the x axis, and the leading edge radius formula is known, but for cambered airfoils it's a bit complicated with MATLAB, I've done all the hard work, and now stuck here.


texts: With wind, what will a perfectly circular flight path relative to the surrounding air look like from the ground?

texts: Let's suppose that an airplane flying at a uniform airspeed follows a perfect, level, closed circular trajectory with respect to the mass of air. Now, seen from the ground, and in the presence of a constant wind, will no longer be a circumference. What would it be...?


texts: Why don't private jets use higher bypass turbofans?

texts: Common private jet engines such as the Williams FJ44 has a bypass ratio of just 2.8:1. Installation requirements aside. From an engineering perspective is there much to gain in efficiency by going to a higher bypass ratio on such small engines?


texts:
In a poignant scene of 1933 WWI film The Eagle and the Hawk (not to be confused with the same-name 1950 western film), while the pilot played by Fredric March performs a loop-the-loop in his – I believe – Airco DH.9 (is that correct?) to evade a German opponent, his observer/gunner falls out of his place and plunges to the ground (he had already been hit and probably killed by the German, but the pilot wasn't aware of it, so this is a real trauma for him).

See the scene here, starting from about 57:25.

Besides the dramatic value of this scene within the narrative, would such a fall as the gunner's be realistic? If those aircraft were capable of such manoeuvres, wouldn't the crew be somehow secured?


texts:
Student pilot here.  I thought I was smarter than this, I’m struggling with this concept.  I got the ASA test prep book and there’s a question asking what happens to the indicated altitude when the altimeter setting is changed from 29.15 to 29.85.  Answer is indicated altitude increases by 700 feet.  Ok, makes sense.
But then I’m reading the aircraft performance chapter in the Aeronautical Knowledge book.  It has a chart about finding pressure altitude, and when the altimeter setting decreases on this chart the altitude increases.  So, the converse of the concept in the question.  I can make either make sense on its own but they seem to contradict each other.  What am I missing?


texts: How to select and electric propulsion system for my experimental Ultralight?

texts:
I've been trying to design and build, my experimental Ultralight using electric propulsion system, My plane designed base on Slaler and Gensis ultralight , following is the primary calculation

Empty weight 120KG

Wingspan 9.1

Length 2.8

cruise speed 120 Km/h

propulsion 20kw

I'm trying to select a pair of Brush-Less Direct Current motors (BLDC) for my airplane, but I have no experience using BLDC's before, whereas there is a lot of BLDC ambiguous options (mostly in Aliexpress) which claim to be a different KW.

My design goal is to find the best possible options for propulsion to have longest possible flight time duration.

Following is the 3D image of my design (located in my GrabCAD account)
any advice really appreciated


texts: What's the difference between a balked landing and a go-around?

texts:
Is there a difference between a balked landing and a go-around?

If there is, what exactly is a balked landing?


texts: What are the differences between direct law and mechanical back-up?

texts:
I am learning for an avionics exam and I cannot find any differences between the direct law and the mechanical backup.

I will describe the laws that I learned such that it is easier to see if I have some misconceptions.

Normal law: Standard mode of operation
Alternate law: (at least two failures detected):

Loss of pitch and bank protection
$\alpha$-protection and high-speed protection replaced by stabilities
Load factor limitation is still active

Direct law: (at least two failures second not self-detected)

All protections lost
Manual pitch trim

Mechanical back-up: (all electric supply for control computers lost)

All protections lost
Manual pitch trim

  Is the only difference between the direct law and the mechanical
  back-up that we do not have operating computers for control?