texts: Can a small GA plane maintain level flight with a significant nose-down attitude?

texts:
Consider a small, one- or two-seater motor GA aircraft, something like a Cessna 152 or similar, designed for level flight at roughly neutral pitch.

It's certainly possible to fly such an aircraft in a nose-high attitude while maintaining altitude, by careful use of pitch and thrust. I'm not sure I'd want to do that for any significant length of time, but as long as the angle of attack is kept below the critical angle for the current aircraft configuration, I can see no aerodynamic reason why it can't be done even in the general case.

But is it possible to fly it in a significant nose-down (say, several degrees or more) attitude while maintaining altitude?

My gut feeling says no; no matter what else you do with the aircraft in such a nose-down attitude, you're going to be losing altitude. But I've been surprised before, so: is there a way?


texts: How do combat jets know when to launch flares to counter IR missiles?

texts:
From my related question, it seems fighter jets do not usually track missiles by radar. Instead, they have a system that warns of radar lock.

So what about infrared missiles (heat-seeking missiles)? Flares are a countermeasure to these, so how does the jet know when one is incoming?

I would be pretty surprised if such a system didn't exist. I want to know more about that system and when it was first implemented.


texts: What are some examples of pilot error with criminal negligence?

texts: I’m having a hard time understanding why pilot error technically can’t be criminal negligence all the time? So I’m curious to find out some examples of this exact scenario, and how investigators determine if ones negligence is punishable by law.


texts: Can a CAP Form 5 flight evaluation be used as the flight portion of a flight review?

texts: I recently completed successfully a Civil Air Patrol Form 5 flight evaluation.  I was told that the Form 5 satisfied the flight portion of the Flight Review.  If true, which additional seminars do I need to complete?


texts: Could the Concorde reliably land with all engines out?

texts: The Concorde was designed to fly at supersonic speeds; because of this its delta wings produce more drag at subsonic speeds. My understanding is that delta wings can produce a large amount of lift at high angles of attack. But is this enough to overcome the other obvious difficulties of an all engine out case caused by, for example, fuel leak?


texts: Did every X-15 pilot become weightless when flying into the upper strato- and mesosphere?

texts:
The North American X-15 was aimed at breaking airspeed and altitude records. The flights that sought to achieve new airspeed records (Mach 5+) were rather leveled but the flights into the upper stratosphere, into the mesosphere and into space were parabolae. Since all of them were parabolic flights, was the pilot always weightless at peak altitude even during the flights that didn't surpass the 50 mi space border? In the stratosphere I think it depended on the rotational velocity of the plane whether they experienced weightlessness, negative gravity or "just" lower positive gravity after engine shutdown.
The same question also applies to any other high atmosphere parabola-flying plane such as Aleksandr Fedotov's MiG-25 reaching 37,650 metres (123,520 ft), Iven Kincheloe's Bell X-2 reaching 38,491 m (126,283 ft) and the SpaceShipOne and Two reaching sub-space altitudes.


texts: Why does it take months, sometimes years, for the BEA and NTSB to complete aviation accident investigations?

texts:
I'm aware that there is a lot that goes into an aircraft accident investigation, so I understand that the investigations take a long time for a reason.

But what I don't know is what those reasons are.  I'm hoping someone with some familiarity can give a high level overview as to why aircraft accident investigations take so much time?


texts: Do I need to change cruising altitudes for really short legs?

texts: Let's say I'm cruising on a magnetic course of 150, so I'm flying at 7,500 feet.  Then I need to fly for 6 miles on a magnetic course of 210, then back to 150.  Do I need to switch to 8,500 or 6,500 for the short 6 mile leg, or is it better to stay at 7,500?  And if I need to switch altitudes for the short leg and I'm getting flight following, do I need to request an altitude change for the short leg and then request to change it back when I resume a course of 150?


texts: Why do electronics have to be off before engine startup/shut down on a Cessna 172?

texts: Can someone explain in simple words why we make sure electronics are off before we start up/ shut down our Cessna172 engine?


texts: What is this plane seen in the Falcon Crest TV series?

texts: Does anyone recognize the make and model of this small plane?  It was used in episode 154 <6.27> "Chain Reaction" of the 1980's TV show "Falcon Crest".  I'm working on a database for the show's picture planes and I am missing the identification of this aircraft and two more planes. Thank you so much for your help.


texts:
When an F-15 (or your favorite fighter aircraft) punches it's external tanks...

...to engage in combat, (or when they are empty), what happens to them?

Through my best reasoning skills and Newton's calculations, I have determined that they will fall.

But what happens when they hit the ground? Do they explode? Do they detonate at a certain height? Is this a problem? Are there regulations determining where/when pilots may pickle their tanks? Have there ever been any accidents? (E.g. houses/cows/grandmothers destroyed by falling fuel tanks?)


texts: What is the effect of non-LASER light sources on pilots?

texts:
After all the media coverage about people pointing lasers at commercial aircraft, I started to wonder what was so special about lasers.

It seems to me that the amount of distraction that could be done with a 5mW laser is significantly less than what could be done with something else.

For example, if I bought/borrowed the light beam from the Luxor hotel, put it in my backyard, turned it on, and pointed it at the planes flying out of a major airport, I would expect that pilots might have some more issues with a 4.3 Billion candela beam than with a 5mW laser (right?)

However, I can't find any laws against it, so would this technically be legal?

Alternatively, what if I just wanted to swing that beam around in the sky, and it accidentally crossed the path of a plane?  Are there different laws regarding unintentionally hitting a plane with something like this?


texts: what are the no load rates of f-16 control surfaces?

texts: What are the no-load rates for the control surfaces of f-16 like flaperon,leading edge flap and horizontal and vertical stabs?


texts: Does ATC clear IFR helicopters for a visual approach if landing at a helipad on a high-rise?

texts: I'm guessing that most helipads on downtown high rises don't have any instrument approaches. If a helicopter is on an IFR to a helipad without any instrument approaches, does ATC just clear them for the visual approach, and do helicopters have their own CTAF frequency for announcing their intentions at off-airport helipads?


texts: What is the benefit of a curved up flight deck?

texts:
A Russian aircraft carrier Admiral Kuznetsov has an interesting aspect: the edge of the runway is raised, which “pushes” the plane in the air during the takeoff. Looking at takeoff videos, the curved edge seems very natural.

All USA aircraft carriers I can think of have an absolutely flat deck, similarly to, for instance, USS Abraham Lincoln:

The Admiral Kuznetsov's curved deck provides benefits, so why were most carriers not built the same way?


texts: Are there cameras which can show external components of an airplane to help pilots determine a fault?

texts:
Looking at this crash - wiki - my question came up - are there passanger planes, which have real time view of external components like engines, wings and so on, which can eventually help pilots understand what part malfunctioned ? If not what would be a good reason ?

Edit: Please note that I am not looking for planes with cameras used for manoeuvring, but for such pointed towards critical components e.g. engines, so if there is a visible fault (smoke coming out of the engine) the pilots would know the exact failed component/part of it.


texts: What is this smoke coming from an F/A-18 shortly before takeoff?

texts:
Watching a video of F/A-18 fighter-jets taking off, I noticed some sort of gas blowing out behind the canopy shortly before the start of the takeoff roll.

Here's a screenshot:

In some videos the smoke is more dense than in others. Has this something to do with cockpit pressurization?


texts: Is there a way to avoid fuel loss caused by vaporization from engine heat?

texts: Concorde had engines directly attached to the wings, close to the fuel tanks. Some fuel was evaporated due to heat. What were the reasons to not use pylons or some cooling system to limit this effect?


texts: Is there a time limit after the ATPL theory exam to get the license?

texts:
If I did the ATPL theory exam now, would I have a time limit to finish the ATPL? If so, what is it?

And what about other EASA licenses, CPL, (E-/CB-)IR, etc.?


texts: How much training does an A320 pilot need to fly an A321?

texts:
From flight simulation and from pictures, it appears that the cockpit of the  A318, A319, A320, and A321 have few if any differences.

Could an A320 pilot fly an A321 without further training?
If not, how much training would he need? Maybe he has to practice landing, because of the different length of the aircraft.
What big differences in the cockpit do those planes have?


texts: Why don't helicopter blades look like other propellers?

texts:
While doing an image search, I found many different shaped propellers and asked about them in this question.

In it, Peter Kampf answered my question with his usual thoroughness. However, as I looked at more images of various shaped blades, I saw images of the helicopters of my youth, Bells. The Bell Huey and the Cobra both have very long, very squared off primary blades. They don't have an aerodynamic looking shape and both the leading and trailing edges are straight.

Why would Bell have chosen this shape and not the shape more like a 'normal' plane propeller?


texts: What is the working principle of trim tabs on the elevators?

texts: Trim tabs are used on the tail's horizontal elevators to adjust its neutral position. What is the working principle behind this? How does this affect the sensitivity (the feel) of the pitch to the pilot in a plane with no fly by wire?


texts: Why would a Mode-C transponder report a different altitude than an altimeter/GPS?

texts:
This is related to a small single-engined plane.

On a recent flight, the controller kept telling me that I was 300 ft higher than it appeared on my altimeter and GPS (which were in sync). This was not a problem on the previous two legs of the flight. However, multiple controllers thought that my altitude was 300 ft higher.

Has someone run into this issue? What could be the problem?


texts: Why are/were there almost no tricycle-gear biplanes?

texts: A friend recently asked me: are there any tricycle-gear biplanes? After hunting around, we found the Waco AVN-8, but that's all. This causes me to ask: is there an aerodynamic or other design consideration which makes a tricycle gear a bad choice for a biplane, or is it just an evolutionary coincidence that the move to single-wing designs shortly preceded the move to tricycle gear?


texts: What are the contributors of lift-dependent drag?

texts:
If someone wants to plot the drag polar of an aircraft, we have

$$ C_D = C_{D,o} + C_{D,i} $$

form/skin drag plus the induced.

However, as I feel, form drag and probably skin friction drag (parasite drag) also lift-coefficient dependent. For example,
as the angle of attack increases, the shape will be different and so the parasite drag will be different  .

Does that increment in parasite drag considered in the induced drag term because it's lift-dependent?

Where should we add this contribution of drag in terms of
the drag polar formula? in the lift-independent part or in the lift-dependent part?


texts: How does a towed banner maintain a steady tilt?

texts:
Today a small airplane is towing an advertising banner, about 20 by 30 feet, in a circular path around my town's university campus.  The banner stays tilted about 45 degrees to make it easier to read by those whom the airplane is circling.  Winds are 10 knots gusting to 20, if that matters.
How can it maintain that tilt?  Surely the tether can't exert a torque on the banner.
Websites of companies such as Van Wagner Aerial Media and Airplane Banners Nationwide say they can do this, but without explanation:

Each advertisement will be tilted, with your choice between zero and 90 degrees, towards your audience.


texts: How large and heavy is the B737's built-in stair?

texts:
Some version of B737 have built in stair, which allows passengers boarding and exit without jet bridge or stair car.

How much do the stair systems weigh? And how much volume do they occupy?


texts: Is the National Aviation Authority the same as the Civil Aviation Authority?

texts: Are the NAA (National aviation authority) and the CAA (Civil aviation authority) the same organisation? According Wikipedia it looks like they are the same organisation.


texts: How do the Kaman K-225 rotor "planes" work?

texts:
I had the opportunity to go to one of the Smithsonian Air and Space museums today and they had a Kaman K-225 on display. For those who don't know, the K-225 is a dual side-by-side helicopter design with an open cockpit:

Source: Own Work

The blades look to be very basic wooden design without any kind of variable pitch on the rotor head. What I found very odd were the "planes" on the rotors:

Source: Own Work

Each rotor seems to have one of these "planes" on it located about 2/3rds of the way from the root. Here is a close look:

Source: Own Work

I wish I could have gotten a better picture but it looks like there is a rod going from the main blade to the smaller "wing" on the device. The rotors seem to be solid, so I'm wondering...

What are the purpose of these "planes" and how do they work (I'm assuming to change the AoA of the blade)?


texts: How does an airline pilot log P1U/S time under EASA regulations?

texts:
I am looking for the exact way to log P1 Under Supervision (P1U/S) time for Commercial Airline Pilots (FOs).

I know as a fact that, as a Pilot Flying first officer, you can log up to 500 hours in P1U/S which are counted as PIC time towards unfreezing the ATPL (must be countersigned by the captain).

However, I am not sure if I need to also log the SIC time in the same entry of the logbook (same flight)? Where can I find the exact regulation about this?


texts: What procedures do I have to follow to fly a seaplane from the US to Canada?

texts: I work in the States and I'm thinking to go visit my friend in Canada. I have access to an Icon A5 and was thinking to fly from my closest lake in Vermont to his house which is also on a lake. What would be the protocols for doing this? Customs wise. Since I believe I would have to file a flight plan. How would immigration work since I am not planning to land at an airport and I'm also not a citizen of either the US or Canada?


texts: Can I fly a quadcopter over 50m above a property I don't own according to the UK's Dronecode?

texts: I have a question about the law on flying quadcopters equipped with a camera in the UK. The dronesafe.uk website states that drones are not to be flown within 50m of any property or people that you do not have control over. Does this mean horizontally or both horizontally and vertically? Basically is it legal to fly a quadcopter above a property that I do not own as long as it is 50m or above the property?


texts: How is DME station ident coded in ARINC 429?

texts: I understand that labels 242,244, 246, 247 are set for DME Station Id or DME Station Ident. they are marked as discrete. How should I convert the station code from alphabet to these 'discretes'? The station codes are something like AGG.


texts: Are VFR pilots required to avoid an isolated cumulus cloud like any other cloud?

texts:
When flying VFR, pilots are to stay free of clouds, which includes a minimum of 3 miles visibility, and 2,000 feet laterally.

Yet, I've seen some youtube videos where it appears the pilot gets too close to a "cotton ball" (a small, isolated cloud) simply because it is along his flight path.

If it is a very small, very isolated cloud, and you can see all the way around it, and have had good visibility on it for awhile as you approach, you know its not a "threat", right?

I suppose the FAA could violate you if you approach a cotton ball, but other than that, is there any reason to deviate and go slaloming around the sky just to keep distance from FEW clouds?


texts: Is the modelname of a flight management system chosen in accordance with the aircraft it will be used on?

texts:
I am looking for information about what modules (not necessarly partnumbers) are used in a flight management system of a relatively new airplane.
After having looked around for quite some time, I found this bit of information with a very nice scheme block.

The flight management system (FMS) they are talking about is the 737 FCMS. However it is not totally clear to me (even after having looked around online), whether this is the FCMS is the one being used for Boeings 737.

Is this the case? Or is that number just coincidence?


texts: Is breaking a FAR an issue when flying outside of FAA jurisdiction?

texts:
When flying outside the US it is advisable to follow the FAA rules when they are stricter than ICAO, and when it does not violate the local flight governing body's rules.

Can you still be fined or get into trouble or does the FAA only have jurisdiction in USA airspace?


texts: Has a jet "engine" ever been made that only uses the thrust from the bypass air and doesn't have a combustion chamber?

texts:
I recently have been looking at different types of jet engines and came to this thread wherein they talk about how most of the thrust from airline turbofan engines (high bypass) comes from the bypass air and not the combusted air coming out of the internals of the engine.

So my question is, has there ever been a sort of fan engine used that only uses bypass air and the fan is run by a separate engine? Would this even be viable?

Edit:
Basically a turbofan that just uses the power of the increasing speed of the air through the smaller space, no combustion (other than the standard piston engine/electric motor/whatever).


texts: What is the difference between a ground controller and an air traffic controller?

texts: In terms of their roles at an airport. I'm designing a system that would inform its users if there is space on the runway that a pilot could use to land or take off, when there is an obstacle on the runway. From my understanding, a ground controller would use this system however the roles of a ground controller and air traffic controller seem to be similar to me so I'm unsure if both would use the system or just the ground controller.


texts: Why did the Flightaware groundspeed readout suddenly spike for this flight?

texts:
My 18yr old son is currently in Barcelona - first time abroad and in a plane. Being an overprotective parent I thought I'd track his flight so I could see when he had landed safely = and save the data for him so he could see his journey.

Anyhow, I noticed weird spike in the flight graph (which I couldn't save). A sudden jump of 200mph in air speed - and equally sudden reduction - at around 15,000ft. No jump in altitude increase though. Also a rapid change in direction.

The flight was on Friday 3rd at around 7.18 am bst leaving from Bristol. Data copied below - any thoughts?

BST Latitude Longitude Course  Direction  KTS MPH feet   Rate
Fri 07:22:11 51.3043   -2.6938 254° West  306 352 10,900 2,338
Fri 07:22:37 51.2927   -2.7573 255° West  322 371 11,900 2,759
Fri 07:23:38 51.2674   -2.8943 360° North 503 579 14,900 2,804
Fri 07:24:24 51.2459   -3.0081 253° West  340 391 16,900 2,365


texts: Which evacuation incidents were followed by a large fire?

texts:
Are there statistics about how many Aircraft emergency evacuation incidents (land-based) in the recent past (say, last 10 years) actually were followed by significant fires?

By "significant" I mean fires large enough to spread to the passenger cabins in spite of fire fighting attempts & which may conceivably have led to fatalities had passengers still been on board.

The context of what I am asking is: Are we doing a good job balancing the upside & downside risks of an Evac? Keeping in mind that most some Evacs can come with serious injuries to passengers.


texts: Why do cargo airplanes fly fewer cycles then airliners?

texts: Reading Why do cargo airlines frequently choose passenger aircraft rather than aircraft designed specifically for cargo?, some answers say that cargo aircraft fly less than passengers aircraft.  Why?


texts:
Planes can sometimes be seen towing banners around large cities or events.

What kind of plane is good for this type of flight? With banners they appear to be flying slower than usual. Is this just an illusion?

What are the practical or regulatory requirements that the plane must meet to be capable? I am tagging with FAA but information about other jurisdictions is welcome.


texts: Why does strong shock wave-boundary-layer interaction produce a bubble reattachment?

texts:
The picture represents a lambda type shock wave, separating the boundary layer at its foot. Separation causes a recirculation bubble to appear. I understand why separation has happened, but what is the exact reason for a bubble reattachment?

The picture is from the book called Shock Wave-Boundary-Layer Interaction by Holger Babinsky and John K. Harvey, Cambridge University.


texts: Should I have one hand on the throttle during engine ignition?

texts:
I'm training in a Cessna 172 for my private pilot license (PPL).

My flight instructor recommended that I keep my checklist in one hand (so that I can keep looking outside with my peripheral vision) and turn the magneto key with the other.

The other day another instructor told me that the checklist should be on my lap and my right hand should be on the throttle, in case I find the setting too high on starting the engine and I need to decrease power immediately.
He sounded like this was something very obvious and said I'll fail my checkride immediately if I didn't have my hand on the throttle.

To be as safe as possible I could put my checklist down, start the engine with the right hand on the throttle, then pick up the checklist again, but is this really what I should be doing, and if I don't will I really fail my checkride?


texts: Why does instability in pitch lower trim drag for an aircraft with a tail?

texts: I have a hard time figuring out why a longitudinally unstable aircraft has a lower trim drag. This seems to be a thing especially in fighter aircraft, so does it have to do anything with supersonic flight as well?


texts: In the US, in actual practice, workload permitting, will ARTC facilities grant SVFR clearance for surface-level Class E "extensions" (E4 airspace)?

texts:
In the US, in actual practice, workload permitting, will ARTC Centers and Approach Control facilities grant clearance for Special VFR operations in surface-level Class E "extensions" (E4 airspace)?
Does the answer vary between different ATC facilities?


texts: What determines the "hang point" and control bar position of a hang glider?

texts:
What is the relation between Center of Pressure (C.P.), Aerodynamic Center (A.C.), "hang point" (the point where the flexible "hang strap" connects to the glider, or the point where the "trike" unit is connected to the wing), and the control bar position relative to pilot's body, if the glider is to fly well, meaning that when I lift hands from bar, the glider will not pitch.

Does hang glider change stability from stable to neutral to unstable when man move his body fore and aft?

I look this video, man must change AoA of wing with bar, so this means no moment(or very little) in this place...
I can't believe how pressure point is so stable/fixed!


texts:
This is a news from Indonesian  local news

This is the translations from google translate.

  Tambolaka - Garuda Indonesia plane seems broken and pushed by people.
  This is a complete explanation from Garuda Indonesia.

  The incident was crowded on social media and commented on by various
  netizens. Considering this, Senior Manager of Public Relations of
  Garuda Indonesia Ikhsan Rosan raised his voice and explained it.

  "It just happened today, it's at Tambolaka Airport (Southwest Sumba,
  East Nusa Tenggara-red)," he told detikTravel, Friday (8/2/2018).

  Ikhsan Rosan asserted, the CRJ type aircraft is not broken. Instead,
  the plane was a little too far as it landed and passed through the
  apron, the aircraft parking lot.

  "The plane should be landing go straight to the left to the apron."
  Well, he passed a little, "he added.

  Then why should be pushed by people?

  "Because there's no pushback car, that's what drives the plane, so it
  seems that it is driven by technicians and airport officers," Ikhsan
  Rosan replied.

  Ikhsan Rosan confirmed, Garuda aircraft flight is fine. Everything is
  running smoothly

My Question is : Is it True that the plane can not taxi backward, so if it pass it's apron, people or a push back car must  push the plane back? Why The plane manufacturer do not give the ability to the plane to move backward?


texts: What would be the advantages and drawbacks of a single-propeller tiltrotor?

texts:
When looking at existing tiltrotors, most of the designs use two propellers, sometimes four. helicopters (and light planes), on the other hand, generally use only one propeller.

Have there ever been designs or proposals using a single rotor (or contra-rotative rotors on the same axis) instead? If so, what advantages and drawbacks did they have? If not, are there specific reasons why this configuration is always ignored?

The most obvious one would be that the engine would sit right on the cockpit, taking its place or at least blocking visibility. But we can imagine a tiltrotor UAV where this would not be an issue.

For the needs of this question, tail-sitters like the Convair XFY Pogo are not considered tiltrotors, as the entire craft changed orientation instead of only the engines.


texts: Asymptomatic Cavernous Malformation been approved for Class 1, 2 or 3 Medical?

texts:
Anyone here with a asymptomatic cavernous malformation been approved for PPL, CPL or ATP?

Recently was concerned with the symmetry of my eyes changing. Opthamologiest ordered an MRI that incidentally showed a small left medial parietal cavernous malformation. This just as I was applying for my PPL medical! The vanity of it all! lol. Anyways, no symptoms, benign, no medications, no treatment suggested.

I'm hoping it won't be procedural denial and turn into a costly and lengthy appeal. Anyone have info to share please?


texts: Why are general aviation avionics so expensive?

texts:
I am quite sure that someone already asked this question, but I couldn't find it on this site.

Why are avionics for general aviation aircraft so expensive?

For example:

The Garmin® G5

$ 2,149.00

The mighty Garmin® G1000

$ ~ 50,000.00

Nobody can tell me, the hardware and development for a small screen costs more than 2,000 dollars. Or two screens with some knobs for the price of a middle-class car. (Of course, those avionics are not bad, they are worth every cent. But it still looks expensive for me.)

What causes this, quite high price?

I guess it's because of high licensing costs to license it for use in aircraft, or are the production costs really so high?


texts: Why does the angle of descent increase in a constant headwind while decreases in a sudden encounter with a headwind, in a descend?

texts:
I'm currently studying aerodynamics.
I have realized that a sudden encounter with a headwind during descent
will result in the aircraft generating more lift, thus angle of descent decreases.
I haven't studied the descent in a constant headwind, but through research I've come across that a constant headwind during descent will increase the angle of descent.
This does not make sense. Shouldn't the angle of descent decrease in both situations? Will appreciate it if someone could explain this.


texts: Do pilots land a helicopter sideways for improved visibility of the landing area?

texts:
When flying helicopters in the PC-based game Arma 3 (not a flight simulator), some of the cockpit have a large instrument panel directly in front of the pilot, obscuring the view of the ground ahead when flying low. However, the cockpit has excellent visibility to the sides.

One of the technique to achieve a precise landing is to land not forward, but sideways. For example, let's assume the pilot is seated on the right, and the helicopter is heading North and approaching a landing target from the South. When the helicopter is approximately 50 feet from the landing target, the pilot swings the helicopter to the left by applying left pedal, pointing the nose to West while keeping the helicopter travelling North. The pilot then completes the landing by looking to the right.

Is this technique valid in real world helicopters?


texts: What temperature are Pitot Tubes heated to?

texts:
What temperature is a pitot tube usually heated to prevent ice?

And are pitot tubes always heated to the same temperature, is there any difference between aircraft (say, a C172 and an A321)?


texts: What rules allow a student pilot to add oil to an airplane?

texts:
A private pilot oral exam guide I'm reading asks a basic question about an issue I had taken for granted:

You have just completed the first leg of a long cross-country and notice that the oil level is approaching the one quart low mark. As a private pilot, can you add the quart of oil yourself or is a mechanic required? (See 14 CFR Part 43)

Clearly this must be preventative maintenance? No. 14 CFR Part 43 Appendix A does not explicitly list adding oil as preventative maintenance.
Searching online I found a lot of forum posts discussing this issue, some suggesting it is "obviously" preventative maintenance per the definition, but 14 CFR Part 1 does not define preventative maintenance, and others suggesting it isn't maintenance, it's servicing, but this isn't defined either.
How does this work if you're a student pilot on a solo cross country? If you shut the engine off and check the oil, are you stuck if the oil is low?
The best answer I can find is adding oil is not "maintenance" or "servicing," it is Normal Procedure per the Pilot Operating Handbook / Information Manual. The Cessna 172S POH as part of the preflight check on page 4-10 states:

Engine Oil Dipstick/Filler Cap -- CHECK oil level, the check dipstick/filler cap SECURE. Do not operate with less than five quarts. Fill to eight quarts for extended flight.

The POH is a little ambiguous how much oil to add, but it clearly states the pilot executing this procedure should add oil.
I believe this how a student pilot can add oil to a plane, or at least a Cessna 172S. Is this correct or is there a better explanation?


texts: Under what conditions may a colorblind pilot fly a Light Sport Aircraft legally?

texts: Are pilots of Light Sport Aircraft within the FAA's jurisdiction required to have color vision? Do colorblind LSA pilots have to take the Operational Color Vision Test (OCVT)? Without the requirement for a medical certificate, where does any testing or certification for color vision come into play?


texts: Why do turbine engines take so long to spool up?

texts: Piston engines reach full rpm within a second or two, but turbines take much longer. Why is that?


texts: How are "expect" altitudes on STARs used?

texts:
STAR charts often have expected altitudes. For example:

This is, of course, different from mandatory crossing altitudes, and it seems a STAR with only expected altitudes would be insufficient for ATC to issue a descend via clearance, though I could be wrong about the second part.

Some charts say "VERTICAL NAVIGATION PLANNING INFORMATION" before the expected altitude, so my assumption is that these altitudes are strictly for planning purposes and allow a top of descent to be calculated.

My questions are:

When you enter the STAR in the FMS, will it pre-populate the expected altitude, and does this show up in the FMS exactly the same as a mandatory crossing altitude?
Are expected altitudes treated as suggestions by pilots or controllers? For example, in the above chart, if you were at JHAWK 15,000ft landing south, and Kansas City Center or Approach told you to "descend at your discretion, maintain 8000", would you (or the FMS) make any attempt to cross RUGBB at 12,000 even though it's not required?
How common is it for ATC to actually issue a "cross [fix] at [altitude]" where the fix and altitude are as expected on the chart? And, if it is common, why wouldn't it simply be mandatory?
Are expected altitudes part of lost communications procedures?
Am I missing anything with regards to the purpose of expected altitudes?


texts: Can you help me ID these two helicopters?

texts:
Hey folks! Desperate to find what these two helicopters are. Any help greatly appreciated!!

A


texts: Is there a roadmap to satellite / inertial only based navigation?

texts:
GNSS is the most accurate mean of navigation available on the flight deck but it relies on satellite being available and under control. Inertial systems are autonomous, but far less accurate.

While GNSS and inertial systems relieve authorities from the burden and cost of building and maintaining terrestrial navaids, terrestrial navaids (VOR/DME) are still imposed as a safety net in case instruments fail (GNSS) or drift (inertial).

As a matter of fact it's not possible to deliver an IFR certificate to an aircraft without a VOR-DME navigation equipment.

Note: Taking comments into account, this last sentence may be not true for IFR certification in the US. However flying IFR in controlled airspace, or flying some approaches may mandate VOR/DME/ADF, depending on the country. E.g. "ADF, DME: Until about 2013, the UK Air Navigation Order required an ADF for all IFR in controlled airspace. The ADF requirement now remains only for instrument approaches that contain an NDB." (source).

Is there any credible roadmap to remove those constraints and have IFR aircraft relying only on GNSS/Inertial? If so what are the mainlines of this new framework?


texts: What requirements aren't met, that would designate an airspace to be Class E instead of A, B, C, or D?

texts:
Quoted from Transport Canada "Class E airspace is designated where an operational need exists for controlled airspace but does not meet the requirements for Class A, B, C, or D."

Class A airspace requires you to be at a certain altitude to actually be in Class A airspace.

Class B is the same, Class C requires ATC clearance for both IFR and VFR.

Class D just requires VFR to have dialogue (two way communcation) with ATC.

What requirements wouldn't be met in a particular airspace that would need to designate it as Class E instead of the other classes?

EDIT: After some further research, the easiest way I've thought about Class E is an area that requires some control strictly for IFR traffic, but to VFR aircraft it's pretty much uncontrolled airspace.

Thank you!


texts: Is there an IATA airport code that is unassigned and that can be used for "any airport"?

texts:
The question is basically up there in the title; I need a default value for an app that won't do anything. A friend suggested XXX, but I'm sure there must be one reserved specifically for that purpose? ;-)

Is there a code that's used in the travel industry to denote "enter city code here" without actually being mapped to a metropolitan area/city/airport? I'm guessing it might be one beginning with Y... :)


texts:
I see this GIF animation a few times then I wonder how many fastener can an aircraft lose before it becomes dangerous. I’m sure losing one wouldn’t be an issue due to safety margin built into every component of aircraft. But how many fastener?

Original link https://www.gifng.com/wtf/65633/


texts:
An aviation expert claimed to me that a propeller is a wing.

While I understand that propellers use similar principles to generate force, it muddied the definition of a rotary wing aircraft vs a fixed wing aircraft.  If the propeller of a fixed wing aircraft is considered a wing, what is the distinction between the two?  Is it how much surface area each type of wing works on?  Is it the direction of force?


texts: Why was my flight cancelled due to bad weather while other flights were not?

texts:
I'm stuck in Frankfurt. I missed my connection due to a delay. I was rebooked, but this new flight was also cancelled due to bad weather.

About 30 percent of all flights were cancelled today. However, if the weather is that bad, shouldn't all departures have been cancelled? Why was the weather bad for my flight, but not for other flights that actually departed?


texts:
I know that ACARS and CPDLC are 2 different systems, so I can compare ACARS vs CPDLC, but can I do the same comparation between CPDLC vs VDL? Or a CPDLC it’s a VDL?

If CPDLC it is a VDL, ACARS it is a VDL also?


texts: Are the Gulfstream III's ailerons controlled by hydraulically boosted cables?

texts: Are the ailerons for a Gulfstream III controlled cables with hydraulic boost? Also, is it possible that an aircraft mechanic could easily access the control to tamper with it?


texts: Can I apply for a commercial-utility licence for an auto-gyro?

texts:
Can an auto-gyro apply for commercial purposes? Utility in remote areas, Alaska for example.

What license is needed (airworthiness, etc.)? How much does it cost approximately?

Can I build my own Auto-gyro and license it to this purpose? Applying for the required FAA license surely will improve the design's safety.


texts: Why has the A340 not been fitted with only three engines?

texts:
The A340 was created because the airlines wanted an aircraft they could cross the atlantic ocean with (They couldn't with their twins because of ETOPS so far). So Airbus upgraded the A330 and added two engines. Because of the four engines, the plane was now allowed to cross the ocean.

However, four engines instead of two increase fuel cost dramatically (I assume). And the A340 is the same size as the A330. The A330 could fly with 2 engines. So why hasn't Airbus built the A340 with three engines instead of four. The fuel cost could have been reduced significantly without loosing the permission to cross the atlantic ocean. For example the MD-11 had three engines and also had permission to cross the ocean.


texts: Does European airspace use the metric system?

texts:
I figured this was probably a no brainer, since Europe uses the metric system, I assume the airspace does...  But then I remembered that aviation likes international standards, and I know the US uses Imperial so, does Europe as well?

And, yes or no, why do they take that choice?


texts: Why did Cessna get rid of manual flaps in their 172?

texts:
At the club I fly at, there is an older Cessna 172 that has a manual "Johnson Bar" that is used to put the flaps down.

In the newer 152, and I believe the rest of the planes (I have yet to fly them), the flaps are controlled via a electronic (or hydraulic?) lever.

It appears to me that the manual flaps are more reliable, more maintainable, and a hell of a lot more fun in my opinion. Additionally, the manually flaps don't require a lot of strength to operate IMO. Does anyone know why the automatic design is favored over the manual counterpart? Same question applies to car transmissions...


texts: What is the most efficient symmetrical airfoil shape?

texts:
What is the most efficient symmetrical airfoil shape to make for a covering for a round upright bar that measures 40mm outside diameter?

The speed of travel will be 25Kph and I also need a shape to travel at 30Kph. I assume these will be different to some extent?


texts: Could a test crew replicate the 1961 DC-8 supersonic dive in a more modern airliner?

texts:
The first airliner to ever break the sound barrier was the DC-8, doing so in a semi-famous dive from 52,000' to 35,000' over the Edwards test range on August 21, 1961.

Could this supersonic dive be planned and reproduced by a suitable flight test crew in a more modern jet transport aircraft?


texts: Can you continue an ILS approach when weather falls below minimum?

texts: If, after passing the final approach fix, weather deteriorates so that the reported values are now below required minima, is it allowed to continue the approach?


texts: How are the glide polar and L/D ratio charts related?

texts:
We know from other questions and answers that airplanes and gliders in particular can have their performance described in terms of glide polar and Lift-to-Drag ratio.

As it appears from the images in the first linked answer (included below), the two are connected to each other.

Despite my research I couldn't find a source on how to derive one curve given the other (the polar given the ratio or the ratio given the polar).

Is it possible to do so? I have heard from friends that are glider pilots that the glide polar curve can be described as a parabola, but I haven't found any reference.

L/D ratio

Glide Polar

Images from this question


texts: How are the landing, takeoff, and cruise speeds calculated for my homebuilt ultralight?

texts: How can I calculate the takeoff, landing, and cruise speeds of my ultralight with a total weight (with load) of 120 kg, average air density of 1.23 kg/m3, wing area of 13.18 m2, and a coefficient of lift 1.15?


texts:
Aircraft use pitot tubes or pitot-static tubes. Do these have some kind of anti-ice system? If so, how? And if not, why not?
I'll just point out that it doesn't seem trivial to de-ice such a thing. A simple heating element at the front would melt the ice but then the water will travel through the tube and probably quickly reform somewhere else. So the entire tube could be heated, but then, that will drastically alter the ambient conditions that the pitot is trying to measure.


texts: Why do some aircraft require type ratings to fly them?

texts:
I know it might seem like a silly basic question, clearly some of these aircraft are awfully complex.  I doubt anyone questions the idea of a type rating for a 747-400.

But where is the line between, "sure, if you can fly you can probably fly this one" and, "you need to know how to fly this plane in particular".  What sorts of functionality cause that sort of distinction?


texts: What is the non-projected cross-hair for on the F-18 HUD?

texts:
Top right, there's a little cross-hair - it looks like it's for lining something up, since on the second pane there's a little dot.

I haven't seen this on any other HUDs. Appears to be present on all variants including Super Hornet.

source

simulated - source


texts: How can an airplane descend faster than a free-falling roll of toilet paper?

texts:
Watching this video, I was wondering, does the Toilet paper have this much lift, because I think the descent speed of the Airplane is not that much?

I don't think that a parachute-plane can catch up with a person in
free-fall?
Can somebody explain me physical how this maneuver works?


texts: What technologies exist to find an aircraft position after it crashed out of line of sight?

texts: What is the best way in the manner of products to find an aircraft after it crashed out of line of sight. Are there defined standards, and what are the selection criteria?


texts: Why is it not recommended to hold the nose up on the A320 after touchdown?

texts: I was recently told by a trainer in my airline that on the A320 if we hold the nose up after main gear touchdown then the flight control laws logic will memorise that pitch attitude after 5 seconds and will hold it there. Can anyone provide clarity on this? I have read the FCTM and know this is not a recommended procedure.


texts: What alternative designs competed for the C-130 in the 1950s?

texts: Which manufacturers and aircraft entered the U.S. government design competition back in the 1950s in which the Lockheed C-130 was selected? Were they all clean sheet designs, modified versions of current aircraft, or unmodified aircraft already in service? Is there any documented history which states justifications for the Lockheed design?


texts: Do the speed brakes on an F-16 change its pitch?

texts: In level flight at 400 knots, what happens when the speed brakes are extended?


texts:
Can anyone identify this aircraft:
This plane was used in a horrible skydiving attempt where the person in the back attempted to climb out but was unable. As a skydiver, this made me very uncomfortable. I am guessing there is a large tail on this aircraft that would have made exiting fatal. The full video is here:


texts: Why are brake temperature limitations lower when the brake fans are running?

texts: In the A320 FCOM it is stated that if the brake fans are running prior to takeoff then the brake temperature must be below 150 degrees Celsius. But if the brake fans are off then our limitation is 300 degrees Celsius. Any reason behind such different limits?


texts: Why is the initial short-field climb below Vₓ in a Cessna 172?

texts:
Short-field takeoff procedure for a Cessna 172R is

  Wing Flaps – 10°.
  Brakes – APPLY.
  Throttle – FULL OPEN.
  Mixture – RICH …
  Brakes – RELEASE.
  Elevator Control – SLIGHTLY TAIL LOW.
  Climb Speed – 56 KIAS (until all obstacles are cleared then $V_y$).
  Wing Flaps – RETRACT slowly after reaching 60 KIAS.

However, best angle-of-climb or $V_x$ at is 62-67 KIAS depending on elevation. Why is the first stage of the climb slower than $V_x$, and if the slower speed gives better performance, then why isn’t that the published figure?


texts: Why do some airports have to put 2 jetbridges on one aircraft?

texts:
At a gate in Denver Int'l there is a United plane with 2 jetbridges.

Why do some airports have to put 2 jetbridges on a plane? Is it necessary?


texts: Are the number of unique passengers per airport counted?

texts:
In airport passenger number statistics, all enplanes and deplanes are added to all direct transfers during a year.

So if I travelled 21 times via Heathrow I was counted as 42 passenger movements at LHR.

Is there anywhere statistics that show the number of unique human beings that travelled via an airport?


texts: On the B737 FCTM, what are the limit values for strong and gust definitions?

texts:
There are definitions called as "Gusty and Strong Crosswind Condition" related to takeoff thrust setting choice and "Strong Crosswind" in  touchdown in crab part of B737NG FCTM.
I wonder if there is a standard crosswind and gust limits. For example can a 15-knot-crosswind be considered as strong? Otherwise what are the limit values for strong and gust definitions?


texts: Why does the CF-100 autopilot have a toggle switch labeled 'ATTACK'?

texts: I took this photograph of the autopilot controls inside the cockpit of a CF-100. There are a bunch of switches for the autopilot. Why does one have a label of "ATTACK" and what did turning it on/off do?


texts: When do pilots facing bad weather turn back (U-turn)?

texts:
Passenger aircraft are not supposed to cross red areas on the weather radar. But what if the weather system is too large to circumnavigate and red areas inside the system are too large/prevalent to avoid ?

What are pilots supposed to do if the required detour around red areas would be impractically long ?

divert to an alternate airport in front of the storm (on the near side) ?
go back to the departure airport ?

Most importantly:
When/where (at what stage of the flight: e.g. PNR minus x minutes, or at a specific distance to the weather front ahead, etc.) is the decision made whether to fly through the bad weather or to abandon the destination airport ? And which criteria is this decision based on ?

I assume this decision takes place between the conflicting priorities of assuring the passengers' safety and the (real-world) pressure exerted by (some) airlines on their pilots to reach their destination airport for financial reasons ?

Please distinguish in your answer flight over land and sea, assuming different considerations apply. For example, the pilot may need to take the decision before reaching the critical point or point of no return. What are the implications of ETOPS for this question ?

The premise ("a weather system too large to circumnavigate and red areas inside the system are too large/prevalent to avoid") may be a particularly common situation when crossing the ITCZ:

   a broad band of high total precipitable water along
  the Intertropical Convergence Zone (ITCZ) (source)

Let me take AF447 as an example – not to say that red areas were unavoidable in this case, but just to illustrate how this flight through the ITCZ had to cross a weather system too large to circumnavigate entirely. Unless turning back, the pilots had to pick and choose "holes":


texts: Could an amateur build a full-scale UAV?

texts: FAA section 333 provides permission to fly in the NAS with an airworthiness certificate. Obviously, the design would need to be perfect with extremely redundant control schemes. Going through the red tape, could an amateur build a UAV the size of, say, an RV-8 and legally fly it like a normal airplane?


texts: Why the different wing and tail designs in similar sized jets vs turbo prop?

texts:
I was flying on Porter Airlines and they had an info card about how similar the Bombardier (I still say DeHavilland) Dash 8 Q400s are to the Bombardier CSeries they have ordered.
There was a cool overlay photo to show relative sizes and shapes:

Looking at that image, it got me wondering about the straight vs angled wing.  Straight vs angled tails, etc.
I get that a jet is faster than a turbo prop.
Cseries cruise speeds are:
Mach 0.78 (828 km/h, 447 kn, 514 mph)
Dash8 Q400 cruise speeds are:
414 mph (667 km/h) 360 knots
Those are pretty close and yet that is a pretty radical wing design change.
Is this just the history an old design (Dash 8) vs a very modern design?


texts: Why does Germany is not so advance in aircraft development?

texts:
I tried to see what countries are the most advance in developing aircraft. I found that Germany is not so advanced (CMMIW). Indeed, there is Dornier there beside has share in AirBus. I don't know whether they are the biggest share holder or not in AirBus.

In another side, among of the G8 countries, US is the leader. They have lot of aircraft industries. Boeing, Lockheed Martin, GulfStream, and many other. Canada has Bombardier. British has BAe with their RJ70, RJ100, so do Roll Royce with their power plant. Italy has Avanti and Augusta Westland, beside small aircraft industries. France with Dassault, Mirage, also joint venture AirBus, and some more small industries. Russia has Sukhoi, Ilyushin, Tupelov, Mikoyan, Beriev, and there are more. And Japan has Mitsubishi, Kawasaki, and Honda, now they are massively develop and  research aircraft, both for civil and military. But Germany is look like not so aggressively take part in this technology like they do in another part. Even China is now growing. With Comac, they has now C919, and now with Russia is developing C929 which will emphasizes their presence in aviation manufacture. ABC, AirBus, Boeing, and Comac are considered as the biggest manufacturer, leaving Germany behind. Is any reason why? Germans probably can explain.


texts:
The Valsalva Maneuver is where a pilot or passenger pinches their nose, closes their mouth, and then attempts to exhale through their nose. It is used to equalize or clear a buildup of pressure in the ear.  I'm always nervous when I do the maneuver, though. I'm afraid I'm going to damage my eardrums in some way.

Can performing the Valsalva Maneuver do damage to the ears, or is it entirely safe?


texts: Where can I find (or how can I calculate) the glide ratio for a PA-28-181?

texts:
I'm filling out ForeFlight's new glide slope feature, and I'm trying to find the glide ratio for a Piper Archer II (PA-28-181). I know the best glide speed is 76, but can't find the glide ratio. Any help on where to find this?

Edit:

Below is the glide range graph from my PoH, and below that is the information ForeFlight is asking for. I'm not really sure how to read that graph to get a glide slope number.


texts: Voltage induced in high-tension magneto ignition system

texts:
Why is there no voltage induced into the secondary winding (in high-voltage step-up transformer) when the ignition switch is closed (OFF).
When the current flows in the primary winding of the coil a magnetic field is generated. This interacts with the flux from the magnet. Assuming that the ignition switch is closed, the flow of alternating current created by the interaction of the two magnetic fields will flow to the ground. Will the flow of alternating current in the primary (while the ignition switch is closed, OFF position) induce a current in the secondary? If it does not, why not?


texts: Where did the 22NM come from in acceptable VOR signal on a MOCA? Why 22NM?

texts: SO a MOCA provides ROC along entire route but acceptable VOR nav signal for only 22NM.  Why 22NM?


texts: Is a Mode C or S Transponder a type of Mode 3 Transponder?

texts:
Mode A transponders are sometimes referred to as Mode 3/A transponders. According to NATO STANAG 4193 (not publicly available, summary from Wikipedia), the "3" in that description refers to the mode in the Identification of Friend or Foe ("IFF") system:

Mode 1 – 2-digit octal "mission code" that identifies the aircraft type or mission.
Mode 2 – 4-digit octal unit code or tail number
Mode 3/A – 4-digit octal identification code for the aircraft, assigned by the air traffic controller (the only mode shared with civilian aircraft)
Mode 4 – 3-pulse reply, delay is based on the encrypted challenge
Mode 5 – Cryptographically secured version of Mode S and ADS-B GPS position.

In flight school I was taught that Mode C was an improvement on Mode A through the addition of data fields that provide aircraft altitude. I extrapolated that to Mode S being an improvement on Mode C through the addition of yet other data fields and making the interrogation targeted at a specific aircraft, and Mode ES/ADS-B being a further improvement through automatic broadcasting.

I have, however, never seen Mode S referred to as Mode 3/S. So, is Mode S a variation within the Mode 3 "protocol" or is it a stand-alone mode outside of the five IFF modes?


texts: Am I likely to get permission at a Private Airport?

texts:
I'm planning a Labor Day flight to a relative's house, and the nearest airport is a Private Airport that looks to be part of a flying community (multiple houses all with hangars directly off the small runway).

I have no experience with private airports.
If I ask nicely in advance, am I likely to get permission to use it?
Or are they likely to be protective of their privacy and airport?

I realize any answer can't apply in all circumstances, but I'm asking if its worth a phone call and conversation? or if I should just go directly to the nearest public airport?


texts: How much pollution is created by an airplane taking off?

texts:
I read on a site that a 747 taking off emits the same amount of air pollution in the first 5 miles or so as 3000 cars. This seems extreme (accepting that the cars will be average).

Are there any more precise comparisons for 2 or 4 engine aircraft?


texts: Why use different data bus for civil and military avionics?

texts:
There are various type of data bus in aviation, the two most common in the '90 were ARINC 429 for civil aviation and Mil 1553 for military applications. They are not very different one for the other, the Mil is a little more complex.

My question is: why use two different data bus? The physical cable is the same (as far as I know, you can correct me if I am wrong) but the protocol is different. I think that what a data bus must do is the same in civil and military avionics, am I wrong?


texts: Just how inaccurate are (Las Vegas) VOR radials?

texts:
I was discussing VOR-based navigation with a pilot, and he mentioned that VOR doesn't provide a very high level of integrity and safety (at least, compared to GPS or DME). He explained that the FAA only guarantees VOR radials listed in approaches and claimed that "one quarter of the radials at Las Vegas are bad".

Are the Las Vegas radials off by just a degree or two or is it worse than that, and how did they get to be so bad? Is it a case of normal variation due to geography and magnetic drift, or is it something more serious like what happened in 2003 to an Airbus A-320-231, G-MEDA on approach to Addis Abeba Airport?


texts: Downstream clearance  means a clearance issued to an aircraft by an air traffic control unit that is not the current controlling authority of that aircraft; but I don't get it so well. Thanks in advance..


texts: Do all the engines/propellers of a VTOL UAV need to be identical?

texts: I would like to know if VTOL UAVs necessarily need $n$ identical propellers and motors. Have any design solutions considered the possibility of using non identical props? For instance 2 motors of type A, 2 motors of type B, and 2 motors of type C. If so, where can I find some studies or some designs that have attempted this kind of solution?


texts: Flight with 9 holding patterns before landing on the wrong airport

texts: Can someone explain why this happened? Quite odd why he cannot get landing clearance from atc. And is this common?


texts: Does a pilot need clearance to enter the traffic pattern?

texts:
In one video, I saw a Cessna that got its instructions to enter the pattern along with landing clearance, but I saw another where the pilot just flew in and got clearance somewhere around late-downwind.

Edit: Still confused here, if you need a landing clearance to enter traffic, then why do diagrams like this exist: (Figure 4 indicating the recommended area landing clearance should be given)

And why do you see so many videos on youtube of late landing clearances? And why do I see people get cleared to land when they're on downwind abeam to the numbers if they already have clearance?


texts: Can stored/leased 737s be used to substitute for grounded MAXs?

texts: The 737 MAX was introduced relatively recently. I would have assumed they were replacing at least some older 737 models in operation with the major airlines that took them (eg Southwest, American, United, in the US). Did those airlines immediately sell off their older planes as the new ones joined their fleet? I see reports of huge flight cancellations from lack of the new aircraft. Since they have common type ratings with the earlier 737, what happened to the older planes that none of them can be pulled from storage or dry leased and put back into service? Surely this grounding is long enough to be worth the transient expense?


texts: Do I need to copy old entries to my new logbook?

texts: i just got a new logbook to replace my cheap paper cover one, just wondering if i need to copy over all the logs(that my instructor wrote) or just leave it and when i need to tally up my hours read two. Is there any rules saying that I cant copy  logs that someone besides me wrote? Should I carry both with me?


texts:
Consider the LOC-D at KSEE and note the Alternate Minimums criteria.

99.9% of the time, the winds strongly favor 27R;
The tower closes at 1900 PT currently (usually at 2100 PT non COVID times);
LOC-D is a circle only approach with a 6.88º final segment;
LOC-D to 27R not available to at night at all I think since it is a circle only approach (given the steepness). However, you can cancel IFR and continue visually usually;
DEBEY to Apt Elev in 3.1 nm is over 1,500 ft / min descent rate at 120 kts (top of Class B approach speed and common for a small turbo jet aircraft such as a Phenom)
Stabilized approach criteria for a Phenom is no more than 1,000 ft / min decent rate within 1,000 ft of the ground;
Circle NA with tower closed or to the northeast;
Local custom is to start on the LOC-D approach and cancel IFR prior to DEBEY. That makes the approach a 2,400 and 3 mi approach.

With the following conditions:

Part 91 in a light turbojet, class B aircraft (a Phenom);
Night with 1,800 Broken / 3 (so below the altitude at DEBEY and beyond where it is practical to cancel IFR even though KSEE is VFR);
Wind from the west at 10 kts (most turbo jet aircraft have a 10 kt tailwind limitation including the Phenom);
Tower closed (so no circle to land 27R) and Class G around KSEE;
There are two RNAV approaches to 9L and 17. If you do one of these, you still have the 27R circle limitation for night and tower closed but they each have lower minima. 17 / 35 is 1200 feet shorter with a cross wind. 9L would have a limitation busting tail wind.

Questions (and my concern are the REGULATORY aspects here) with the airport 1800 and 3:

Can the LOC-D be flown with the tower closed at all? (The Alternate Minimums clearly state Circling is NA with the tower closed and LOC-D is a circling only approach. But aircraft are commonly cleared LOC-D approach with tower closed...)

Can you land on 27R with some interpretation of IFR rules?
a. If you fly LOC-D with with tower closed, is completion of that approach NA? As a practical matter, on LOC-D, you would break out at 1800 about 1.5 miles from the airport decending at 1500 fpm at night trying to break in to cancel IFR with SOCAL... You can descend to a VFR pattern height and complete the pattern VFR and buy time to cancel.
b. Can you fly one of the approaches and cancel IFR and complete the approach VFR?

What are the limitations on when during an approach you can cancel IFR and legally complete the approach VFR?


texts: Are there any data on the safety rate of gliders vs single-engine GA aircraft?

texts: Can anyone point me to statistics on the safety record of gliders vs. single engine general aviation aircraft?


texts: What equation describes the relation between engine thrust and EPR?

texts:
What is the formula for engine thrust as a function function of engine pressure ratio (EPR)?

If the EPR is lower than 1, is the engine producing thrust? For example during descent, when the engines are in idle power.


texts: Is the APU classified as a component of Airframe or Powerplant?

texts: In the classification of systems and components on the aircraft - is an APU classified under the Airframe or the Powerplant?


texts: Why are jet aircraft never designed with a slower cruise speed?

texts:
All jet airliners have a cruise speed between Mach 0.82 and Mach 0.85.

At those speeds the aircraft are flying at their maximum subsonic speed. Any greater cruise speed would only be possible with major design changes.

My question is about fuel efficiency.

As drag increases with the square of speed, would a slower cruise speed lead to better fuel efficiency?

So why are jet aircraft never designed with a slower cruise speed?

If transonic phenomena didn't exist, would a faster speed be more fuel efficient?

Currently some airliners, after flying a 12-hour route, stay on ground for a long time before returning. Wouldn't a slow flight (if it is more fuel efficient) be better in this scenario? So not to waste time on ground?

On long-range flights, any fuel saving significantly increases the flight's profitability.


texts: How does an airline decide when to cancel a long haul flight permanently?

texts:
BROAD QUESTION WARNING: Obviously the airlines cancel the routes because they are not making money, but would that not have been factored in when they start a route? For example, the current SFO-BLR route seems to be fully booked all the time (a friend flew on it recently), but it would not easily be scrubbed given that Air India is still a government owned airline.
Similarly international airlines would not start new flights to Phoenix because of its proximity to LAX. But there is a sizeable amount of traffic that flows between PHX-LHR (It used to be 2 daily direct flights out of PHX pre COVID)


texts:
Can anyone point me to why Burt Rutan's Voyager is a canard?

In other words, what reasoning could be behind it. What problems Burt Rutan might have tried to solve by using Canard configuration in this specific aircraft
and why those problems may not be solvable or less feasible in a conventional configuration?

For  comparison I would prefer to use predator or global hawk.

I believe this is because noticeable CG shift during flight and possibly has some advantage in relation to dynamic responses.

But I would like to get a second thought from you guys.

PS: English is not my mother language so apologies in advance if Im not clear enough. Unfortunately the answers I've got so far are either not very well thought or incorrect.


texts: Post MH370, are there developments to improve the tracking of airliners? Is there any technology being developed that would utilize the smartphones of the passengers?  MY question include smartphones and inflight wifi being standard or at least looking to be standard in the near future


texts: How will aiport operations at KOAK be affected when taxiway W is promoted to a runway?

texts:
For the record, my question is not about mistakenly using a taxiway as a runway.

I've noticed recent changes to the sectional and TAC VFR maps around Metropolitan Oakland International Airport (OAK/KOAK) - it appears that Taxiway W is being "promoted" to a runway close to, and parallel to, Runway 12/30.

Based on the airport map (PDF) and confirmed by the Google Earth image below, aircraft departing and landing on 12/30 (presumably soon-to-be 12R/30L) will have to taxi up or down this new runway.  From the looks of it, this runway will just be marginally long enough (about 7200 ft / 2195 m) to handle short-range commercial operations; certainly the longer runway will still need to be used.

This then begs the question:  How would airport operations be affected if both runways were active?

From Google Earth and Skyvector.com


texts: What amount of lift would be created in the fallacious "lift from equal transit time" theory?

texts:
Context

A wrong --but simple to understand-- theory for lift states:

Air molecules that were close before being separated at the leading edge must be close again after they join back at the trailing edge. For this to happen, molecules must travel the two paths in the same time.

As the path is longer on the upper side, due to the camber of the wing, air is accelerated on the upper side. By Bernoulli's equation, static pressure decreases when velocity increases, so the pressure is lower on the upper side, and higher on the lower side.
Lift is the force created by this pressure differential on the wing sides.

(What is wrong is not Bernoulli's equation, but the assumed relationship between path length and speed.)

Such theory is, for instance, presented as correct in this book.

More at Nasa.

Question

We know this theory is wrong and lift created by path length difference would be a very small percentage of the lift actually measured (and even null for symmetrical airfoils).

Let's assume a rectangular wing with a simple cambered airfoil, at the critical angle of attack:

What would be the pressure differential according to equal transit time difference? What percentage of actual lift does it represent?


texts:
I'd like to make an app (for personal use) that plots where a plane has been over the past day, week, etc.  Is there a free API or dataset that would have that information? I've already looked at a few:

https://aviationstack.com/documentation: none of the free endpoints give previous flights by a specific aircraft
https://developer.flightstats.com/: free trial only 30 days, not clear if it's available for personal use
https://www.adsbexchange.com/data/: has good info on current ADSB data (i.e. current position of planes) but as far as I can tell there's nothing for querying past data
https://flightaware.com/commercial/: no free option
https://www.flightradar24.com/commercial-services/data-services: no free option
https://opensky-network.org/apidoc/rest.html: this seems like my best option so far, but it has incomplete data. E.g., https://opensky-network.org/api/flights/aircraft?icao24=a7bba1&begin=1608729654&end=1609388755 is missing flights to/from Memphis for some reason and has an incorrect arrival/departure for some results.

Are there any other options anyone is aware of?


texts: When would CAPT 3 or FO 3 ever be used on the A320?

texts: On the Airbus A320, on the very top of the Pedestal and right below the bottom ECAM there are switches saying ATT HDG and the you can either switch it to CAPT 3 or FO 3 same for the other switches in that row AIR DATA, EIS DMC, and ECAM/ND XFR. I think they are for if the Captain or First Officer has custom gear or equipment. Please explain what each switch means, whats it's use, and when would they be used.


texts: What is the purpose of the winglets on the Socata TB-31 Omega vertical stabilizer?

texts:
Aérospatiale-Socata built a prototype of the TB-31 for the French Air Force, which never went to production:

Source: netAirspace.com, photo by miamiair

What is the purpose of the winglets at the top of the vertical stabilizer?


texts: What are the pros and cons of adding a gearbox to larger jet engines?

texts: What are the merits and demerits of adding a gearbox to larger jet engines like the Trent 900.  If its about torque, why not use a magnetic gearbox?  What are the demerits of using magnetic gearboxes in a geared turbofan engine?


texts: Do thrust reversers only have idle and full modes or are there intermediate settings?

texts:
Are there any intermediate thrust reverser settings?

If so, how often do pilots use these intermediate settings?


texts: The question is on my mind, because many passengers think there is no need to wear the seatbelt when the seatbelt sign is not illuminated.


texts: Is there a database of aircraft 3D models that are accurately created

texts:
I was just wondering if there was such a thing as the title describes. I am trying to work on a machine learning algorithm that generates aircraft designs based on what it learns from current designs, where I think the appropriate dataset format is in 3D model form.
If there exists no such database/dataset, I think I might have to find each design plan of individual aircraft and extract as much information as I can (if that's even possible)


texts: How is The Published Runway Touchdown Zone Elevation Decided?

texts:
The touchdown zone of a runway can be up to 3,000 feet long if the information I have is accurate.

How is the published Touchdown Zone Elevation determined?  Is it the center, an average of the elevation of the entire touchdown zone, or something else?


texts: Why was the Akron’s spy basket installation so remarkably unstable?

texts:
A spy basket (also known as a cloud car) is a type of airship appurtenance consisting of a streamlined one-(usually)-person gondola attached to its host airship by a long cable; to use it, the host airship hides in or above a cloud layer, and the spy basket is then lowered, cum crewmember,1 from the airship down through the base of the cloud deck, and serves as an observation station in the (hopefully) clearer lower-altitude air, allowing the airship to know what happens to be below it without exposing its gigantic soft underbelly beneath the clouds.2

It was pioneered by the German armed forces during World War I, who used (or at least tried to use) it to drop bombs on Londoners3 without getting shot down; they eventually discarded the whole concept, but it was picked back up, five seconds over a decade later, by the United States Navy (the only post-1918 military user of rigid airships),4 when the U.S.S. Akron (ZRS-4) was built with provisions for the fitting and use of a spy basket.  The Akron’s spy basket was first deployed in April 1932.

It did not go well:

  Soon after returning to Lakehurst to disembark her distinguished passengers, Akron took off again to conduct a test of the "spy basket"—something like a small airplane fuselage suspended beneath the airship that would enable an observer to serve as the ship's "eyes" below the clouds while the ship herself remained out of sight above them. The first time the basket was tried (with sandbags aboard instead of a man), it oscillated so violently that it put the whole ship in danger. The basket proved "frighteningly unstable", swooping from one side of the airship to the other before the startled gaze of Akron's officers and men and reaching as high as the ship's equator.[18] Though later improved by adding a ventral stabilizing fin, the spybasket was never used again.[26]

This was not, so far as I can tell, a problem faced by the German airship bomber crews of World War I (who were blessed with spy baskets that dangled placidly from their mounts), and I’m having trouble seeing why the Akron’s spy basket would exhibit such remarkably unstable behaviour, unless the first (and only) trial of her spy basket was held in severe turbulence (which, given the purpose and method of use of the spy basket, I’m having great trouble believing that her commanding officers would have allowed).  Can someone clarify this for me?

1: Presumably the one with the most favourable combination of good vision, non-acrophobia, and low rank.

2: It can also, if necessary, be used to determine if the cloud deck does, in fact, have a base, or if it extends all the way to ground level.  Obviously, due to the likelihood of eventual ground/water/tree/automobile/watership/Paul Bunyan contact in the event that the cloud layer is continuous to ground level, this is only advisable when the airship is in a stationary hover, unless you really don’t like the person manning the spy basket.

3: And probably some other people, too.

4: The German military, having lost World War I fair and square, was forbidden to build, use, possess, rent, touch, or think dreamily about any sort of aircraft at all, lighter-than-air or heavier-than-air, while the British military, in order to save money, scrapped its fleet of rigid airships at the end of the war and cancelled all those not yet delivered (with the sole exceptions of one they were going to sell to the Americans but which, due to poor judgement on both the designers’ and the pilot’s parts, crashed while they were showing it off for its prospective customers and one which was hastily reconfigured for passenger service but proved too small for the role).


texts: Are any software or aeronautical engineers yet attempting to design pilotless passenger planes (PPP'S)?

texts: With all of the effort currently under way to attempt to create driverless land vehicles (which I believe may be a rather misplaced effort) has anyone yet heard of any serious efforts also being made to one day try to eliminate passenger jet pilots as well?  As a former private pilot myself, such a thought seems rather ludicrous, but just wondering.  It seems to me the elimination of humans from overseeing human safety concerns such as flying or driving, would simply be "unsafe."


texts: What kind of Gyros are being used in smaller regional jets?

texts: As per my understanding, most of the Gyros in big jets are electric driven but I am not sure if the smaller planes also have the electric driven or vacuum/pressure driven Gyros?


texts: What is the minimum altitude over Egmond aan Zee when landing at Schiphol?

texts:
I live in Egmond aan Zee which is about 36 km flight distance from Schiphol.
It seems that aircraft fly over Egmond when there is a southerly wind so they can make a landing approach to Polderbaan runway.

Where can I find the minimum allowed altitude when flying over Egmond?


texts: What does this statement about steep descent mean?

texts:
Source: Wolfgang Langewiesche - Stick and Rudder; An Explanation of the Art of Flying

In the first chapter the author mentions, in a glide, if you want to descend more steeply, you want to want to point your nose less steeply.
And if you want descend less steeply you point your nose more steeply.

What is the reason for this?


texts: Regarding N1 and N2, what does the "N" stand for?

texts:
I initially phrased this question in a comment to another question regarding what N1 and N2 mean, hoping it would be that sort of low-hanging fruit that is easily answerable and not worth a proper question in its own right.  But then I starting searching and came up short.

This Yahoo Answers page has lots of guesses on it, from "nominal" to "Newell".  (And we all now are reminded why nobody goes to that site for real answers.)  Many other pages explain what N1 and N2 are, but not where the "N" part comes from.

I'm wondering if it might have its origin in German, as a lot of early developmental work on jet engines was done in Germany.  Or was it simply an unused letter that fit?


texts: Can a commercial airline pilot, flying either A320 or B737, charge people for a flight in their own personal Cessna 172?

texts: Or would they have to be some registered business for the industry?


texts: Is there some functionality of an airliner which is not controlled by the cockpit?

texts: We have had a blockbuster question, asking about the complexity of the cockpit, which was answered very well. With so many controls, are there any flight- or safety-critical functions which cannot be controlled by the cockpit?


texts: In what conditions is the APU used in midair?

texts:
In flight, engines provide all the needed energy (bleed air, hydraulic and electrical power). So the APU can be shut down shortly after engines are running. But I imagine that starting the APU in midair is a well known procedure because:

I understand that starting the APU while the engines are still running is common given the answers to this question (even if done when the aircraft has landed)
In the US Airways 1549, the APU was started in midair [1]

How is the APU used in midair? When is it started/shut down while the aircraft is not on the ground?

If needed, the answers can be restricted to airliners.

[1] NTSB report p.19


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

texts: I was just reading about Aircraft Conditiong Systems and found that, the A.C. mechanism begins with compressor in the engine. Do these compressor also work the way in which AC/Refrigerator's compressor do? If they do, then Freon Gas Leaks should be something happening atleast once in a long period .. They are pretty common with household Air conditioning system.So, does this happens? I have never really heard of something like this happening to an aircraft..


texts:
Could someone explain what aerodynamic damping exactly is? I'm not able to understand the whole concept. Pls try to keep the explanation simple.

I tried to understand the concept from the link below. Is aerodynamic damping the same as the dihedral effect, or is that a whole different story?

https://encyclopedia2.thefreedictionary.com/aerodynamic+damping


texts: Is "Pull up and be ready" standard phraseology?

texts: I was next in line (making IFR departure) just after a Bonanza departed, with about a dozen aircraft behind me. Tower called my number and said "pull up and be ready".  I'm accustomed to "line up and wait", changed from the old "position and hold", so I was expecting "line up and wait".  We're always taught to get clarification if we don't understand, but the tower guy seemed disgusted with me for asking, as if "pull up and be ready" is "duh"... standard phraseology.  I've never heard it before, or since, so am I needing to study the AIM a little bit more?


texts: How does the particular piece of flap behind an engine on a B777 work?

texts:
On several B77 photos, I notice that flaps just behind the engines are not always coordinated with the others flaps. On this photo flaps are extended but not behind the engine whereas on this photo all flaps are extended. Given the position of this particular flap, I suppose there is something to do with the interaction between flaps and engine. Given the difference between the two photos, it may also have something to do with spoiler extension.

EDIT: OK the two photos are not the same plane, but I find a video where it is obvious this piece of flap is not always coordinated with the rest of the flaps. When looking at the video I first thought it was a flaperon, but after the flaps are extended, it deflects upward several times without making the plane banking.


texts: What error is left uncorrected when "fast IRS align" is done?

texts:
As far as I understand, there are two ways to align the IRSs in B737s: "Full align" and "fast align."

For a full alignment, you rotate the IRS selector from OFF to NAV, and for a fast alignment, you roate the selector placed at NAV from ALIGN back to NAV.

The 737 FCOM explains that a fast alignment "automatically updates alignment and zeros ground speed error." What error is left uncorrected when "fast IRS align" is done as opposed to when a full alignment is made?


texts: Can the Safety Pilot log an approach if acting as PIC?

texts: Suppose you are acting as Safety Pilot and PIC on a flight in IMC. Further suppose that the pilot at the controls is instrument rated but his or her IFR currency has expired. If the other pilot acts as sole manipulator of the controls during an approach, can you, as the PIC, log that approach as well? Assume the approach is loggable given weather conditions, etc.


texts: How do terms apron, ramp, tarmac, taxiway, parking area, gate, hardstand relate to each other?

texts:
The terms apron, ramp, tarmac, taxiway, parking area, gate, hardstand are used in a way that I cannot understand.

Boeing Everett Factory. Photo by Andrew Hunt at Airliners.net (url unknown). Cropped image from this page

I can't figure out if one is generic and another a part of this set, or if they are well defined by their use (taxiway), or anything else.

Questions I can't answer:

Is this a binary split: Runways vs tarmac?
Is the gate stand part of the tarmac?
Is a parking area different from a ramp?
Is a taxiway considered part of the apron?
Are aprons made of Tarmac (tarmacadam)?
Is a de-icing area part of the ramp?

etc.

In addition I guess this may varies between countries and/or aeronautical jurisdiction.

Can someone provide an accurate view of the lingo and explain whether some are related or synonymous? (filling the blanks if some important term is missing).


texts: Could a fighter aircraft be operated indefinitely?

texts:
Is it possible for an air force to operate a fighter aircraft indefinitely?

Suppose a country has some Mig-21s or Mirage-IIIs. Is it possible for them to operate those aircraft indefinitely by continuously overhauling and upgrading them?


texts: Is it allowed to wear polarized sunglasses in cockpit?

texts:
Is it true that Pilots are not allowed to wear polarized sunglasses?
What is the worst thing that can happen if wearing polarized
sunglasses in cockpit?


texts: Were there any test flying incidents during which the pilots managed to escape the plane?

texts: I am only asking about flight testing civilian jets, not military ones. I know that all test pilots have to be equipped with a parachute, so I wonder was there any incident where the test pilots and test engineers had to leave the plane during the flight, and managed to reach the earth? Alive or dead.


texts: When can I start an approach if I lose comms and my clearance limit is not an initial approach fix?

texts:
Here is the AIM's definition for a clearance limit:

CLEARANCE LIMIT− The fix, point, or location to which an aircraft is cleared when issued an air traffic clearance

Assume a clearance such as:
"Cleared to Los Angeles Internal Airport (KLAX) via..."
This means our clearance limit is KLAX.
But what does this mean if I follow the instructions in 91.185?

If the clearance limit is not a fix from which an approach begins
[it's not], leave the clearance limit at the expect-further-clearance
time if one has been received [it hasn't], or if none has been
received, upon arrival over the clearance limit

A pilot should fly until the last fix on the route and then direct to their clearance limit: KLAX at their last assigned altitude (let's assume FL280).

and proceed to a fix from which an approach begins

Now fly direct from KLAX, with no assigned route, to an Initial Approach Fix (CRCUS or SEAVU).

commence descent or descent and approach as close as possible to the
estimated time of arrival as calculated from the filed or amended
(with ATC) estimated time en route

Hold at SEAVU or CRCUS (for which there is no published hold--so they can make one up), UNTIL their ETA into LAX. Then, descend in the hold and fly the approach. Or, realizing these fixes are 35nm away from KLAX, would a pilot turn around half way between SEAVU and KLAX to return to SEAVU at their ETA to descend?
Is that crazy to anyone else? To follow this regulation, a pilot would fly over their destination airport and then return to an IAF to do an approach. Does ATC really want us to do this in a lost comm situation? At a minimum, this doesn't seem like a prudent use of fuel which brings safety of flight into the mix.
When and where can I legally start an approach in this scenario?


texts: What is the reason to have LOC/VNAV landing method?

texts: What is purpose of mixing LOC/VNAV in this landing method?


texts: Cessna 172: at which RPM should the oil pressure reach the green arc?

texts:
I am part of a team developing a Cessna 172 P model for FlightGear, an open source free flight simulator. We are now trying to improve the oil pressure and temperature simulation, and we have a question concerning the behaviour of the oil pressure at startup. The oil pressure gauge in the model P ranges from 0 PSI until 115 PSI, with a green arc region between 50 PSI and 85-90 PSI. What we are trying to figure out is in which circunstances the needle should be in the green arc region.

I have checked many different checklists for the 172 and many state that the throttle should be at 1000 RPM for the oil check, so that the oil pressure should be at least 50 PSI. On the other hand, the 1982's POH does not state that the oil check should happen at a particular RPM; it only says that the throttle should be OPEN 1/8 INCH on p. 4-7. But the POH is quite confusing concerning this issue, since it simply says Oil Pressure -- CHECK but not that the oil should be on the green arc. To add more confusion to it, on p. 4-12 it says:

  After starting, if the oil gauge does not begin to show pressure
  within 30 seconds in the summertime and about twice that long in very
  cold weather, stop the engine and investigate.

So nothing again about the green arc or 50 PSI, just about the gauge being alive. This is perhaps the reason those checklists include the 1000 RPM figure, perhaps the engine is not able to give 50 PSI or more of oil pressure when at idle (aprox. 750 RPM in the case of our model).

TL;DR

in the Cessna 172P, at which RPM should the oil pressure be equal to or above 50 PSI?
what is the procedure for oil pressure check, should it be done at 1000 RPM or at idle throttle?


texts: Why are some jet trails longer and some shorter?

texts: One can see  jet trails behind an airplane. I know that they form because of rapid condensation of Jet exhaust. But I can't figure out why some remain for too long time (hence, longer) while  some are smaller and disappear rapidly.  Does this depend on height of airplane or some other parameter ?


texts: Why can't an Airbus A330 dump fuel in an emergency?

texts:
It was reported recently that the Swiss flight LX18 from Zurich to New York had detected an engine issue shortly after take-off and decided to land back in Zurich.

Apparently, the Airbus A330-343 cannot just dump the fuel and, fully tanked, was too heavy to land safely, so it had to fly for 5 hours in a loop just to burn the excess kerosene.

Would it have been too complicated to implement a fuel draining mechanism?
What would have happened if they couldn't fly for 5 hours and had to emergency land right away? Wouldn't this inability to drop fuel be a safety hazard?


texts: Do I need to keep my foreign based PPL after passing an FAA instrument checkride?

texts:
I have a foreign based PPL (PPL issue on the basis and valid only as long as my foreign PPL is valid). I'm going to go for an instrument rating checkride very soon.

Assuming I pass the checkride successfully, does my license become valid regardless of my foreign one or do I still need to keep both?

I lived in the US for the past 10 years and I am a US citizen.


texts: What effects to controllability are there when the rear doors are opened on a KC-130?

texts:
Many years ago, I was part of a LRRP drop taking photos from inside a KC-130 aircraft. The rear doors are (relatively speaking) huge. The top half pivots up and into the craft, while the bottom half descends down and (I assume) into the airstream.

When the main doors are opened like that, how does that affect the stability and controllability of the airplane? Would the pilot have to trim down or up, or do nothing?

While my personal experience is that plane, I wonder of any plane that opens large portals into the airstream.


texts: How is the speed of a helicopter controlled? Does the pitch of the blade vary for speed while rotor blade moves at a constant speed as with turboprops? Or is there a throttle mechanism for varying the rotational speed of the rotor for forward airspeed?


texts: What's the appropriate course of action if an airliner bounces 5-10 feet on touchdown?

texts:
I regularly fly in a PC flight simulator, and I'm currently trying to refine landings in medium-to-large airliners in various weather conditions.

A problem I've faced in some conditions while flying the 737-800 has been bouncing on touchdown, where I lose just enough lift in the last few feet of my approach to touch down firmly on the main gear only, before bouncing back up 5-10 feet.

While I'm already looking into avoiding this kind of bounce whenever possible, I'd like to know what common procedures are in this situation assuming the gear is left intact and there's no urgent failures or factors (such as a fuel emergency) which would time-constrain a landing. Specifically; would a real-world flight in this situation go around, adjust thrust, adjust flare, or do something else entirely?


texts:
Since a very large sum of your ticket goes to airport tax, I was wondering how do they justify it and what is it used for?

Take your tax paid on your ticket and multiply it with the number of seats on that airplane and you realise that, per flight, the airports are receiving a substantial amount.

Is it all going to the government?

This question is very 'general' and just to get a loose idea of what the tax goes for. To get detailed information of every country is unnecessarily complex.


texts: What is the purpose of the sharp pods under airliner wings?

texts:
What are the pods with the sharp trailing edges underneath the wings of large airliners, as shown in the image below?

My best guess would be fuel tanks


texts: Is it normal for instantaneous GLOC to occur at 5 G's?

texts: Is it normal for a trainee to have an instantaneous G-force induced loss of consciousness (GLOC) at 4-5 G's in a light military trainer aircraft like Socata TB 30 Epsilon, after doing a manoeuvre sequence?


texts: Can anyone identify this pusher biplane?

texts: This plane was probably built around 1912. I do not know by what company built this. Does anyone know what airplane this is?


texts: Which part of the boundary layer(chordwise) contributes most to friction drag? fore? aft? Why?

texts:
along the chord of a wing/airfoil section, which portion of it creates the most friction drag through the boundary layer?
Is it in the fore section, close to the stagnation point? or the aft section


texts: Was differential thrust used in the P-38 to improve turn performance?

texts: In the P-38 Lightning could differential thrust be used to improve turn performance ? If so what was the procedure ?


texts: How can shifting to TCP/IP make current aviation systems more delay-tolerant?

texts:
I've recently been reading a number of articles on the current aviation systems. Many of them say that the current aviation infrastructure is 'inefficient' since it is based on OSI model and, so, Eurocontrol/FAA are trying to shift to a TCP/IP model (without further elaboration as to why it is inefficient.)

As far as I know OSI and TCP/IP are both protocol stacks and pretty much follow the same ideas.

I'm not quite sure why they say that the current OSI model is inefficient? In what sense is it inefficient?

Another point, in the articles I read, which I thought was a bit vague, was that it said that the TCP/IP model is more 'modular' and can improve 'flight delays'.

Again, weren't both OSI and TCP/IP models created to make systems more modular? How can shifting to TCP/IP make current aviation systems more delay-tolerant given that the main cause of delay is air traffic and weather?

Articles I've read.

This one is the main article, published by Eurocontrol/FAA, that I read. It suggests a transition from a voice-based to data-based services network.
This one is a PhD thesis. See Section 3.1 for the main references. They refer to the TCP/IP ATN as ATN/IPS. Search for the word 'ATN/IPS'.
This one gives a detailed description of ATN/IPS.
The following claims that a TCP/IP model is more modular than the current OSI based model.


texts: Does rolling or yawing affect the angle of attack?

texts: If I'm on final in windy conditions and I need excessive rolling and yawing movements to stay on centerline and say, my pitch stays constant - does rolling or yawing change my AOA such that I could stall?


texts: Do any aircraft have a "self-contained ILS"?

texts:
The ILS is an invaluable aid to pilots, especially those operating to/from the many airports where poor weather is common (low-visibility operations would be completely impossible without an ILS); however, ILSs are expensive and maintenance-intensive, with the result that many smaller airports lack ILS capability.  Also, the requirement for a considerable quantity of pre-emplaced infrastructure obviously precludes one from performing an off-airport instrument landing.

On the other hand, the technology is available to guide an aircraft down to a precision landing at an arbitrary point on the ground, and much of this technology is already mandatory equipment on aircraft; GPS (which most if not all aircraft already have anyway) could be used for horizontal positioning and guidance and for plotting a landing route about the local terrain, the radar altimeter (also standard aircraft equipment) would provide vertical guidance, and a forward-looking radar system (also already standard, in the form of the aircraft's weather radar, which should only require an additional driver or two to add a terrain-sensing mode) would allow fine control of the aircraft's flightpath for the landing itself (where GPS, with its ~10m CEP, is insufficiently precise and accurate for a safe touchdown) and allow the aircraft to orient itself in space (as GPS tells the aircraft where it is, but not which direction it's pointing).  Additional equipment that would be useful and could easily be added would be a second weather radar (to allow the pilots to continue to monitor the weather even with one radar in terrain-mapping mode), a Doppler radar system (to warn the pilots of dangerous windshear, microbursts, etc.), and a forward-looking lidar system (to provide advance warning of clear-air turbulence along the approach path).

With the appropriate software, these instruments could be used to plot and fly a safe instrument landing at a noninstrumented airport, or even at a non-airport; this latter capability would be extremely useful for medevac and SAR pilots (whose duties, by their very nature, involve operations to and from off-airport locations, frequently in poor weather) and for military helicopter pilots (same reason).

Are there any aircraft already equipped with such a "self-contained ILS"?


texts: What is the function of the hole at the rear of the airplane?

texts:
What is the function of the hole at the rear of a plane?
I searched online but didn't get a satisfying answer.


texts: Are there any plans to make the QF-16 into a drone for actual combat missions, or a fully autonomous fighter?

texts:
It appears to a naive layman like myself that the QF-16 is an excellent platform to use for remote controlled missions akin to that of other drones. Except that the F-16 appears to have a broader mission envelope than a Predator or Global Hawk. For one, the F-16 is in general quite capable against the majority of the world's active combat aircraft. As I'm sure anyone qualified to answer knows better than myself, it has a proven record in a variety of air to air missions, dogfighting, and ground attack missions.

Are there any other drones, besides the QF-16 that are even remotely as capable, in comparison, and that already exist, in large numbers, like the QF-16?

The benefits of this should be obvious. The QF-16 is after all a disposable aircraft, yet one that is at least somewhat capable. With a drone, no pilot life is at risk. With an autonomous drone, no pilot is required at all for the actual fight, only planning of the mission. This should be an obvious advantage, and from what little I can tell, various---albeit less capable---drones exploit this advantage already.

Just to provide some more context: Many interesting things can be easily imagined, the F-22/F-35 often talks of using fourth generation aircraft as a "force multiplier" by feeding them data from its sensors, such as target information. Such a force multiplier with autonomous, disposable aircraft seems rather interesting to say the least.

I'd like the know if there are any plans to use the QF-16 as a drone for combat missions, and if not, why not?

I'd also like to know if there are any plans to use the QF-16 as an autonomous fighter, as in, program the target into the aircraft, and send it on its way, and have it return, all without any pilot input.

The last question is the most interesting to me. Is there any publicly known research in this direction? Towards making autonomous combat aircraft? Perhaps the QF-16 platform is greatly underpowered both in terms of hardware and avionics (sensors) to realistically (even if the software could be developed) to act in such a manner.

Are there any plans for such things? If not, why not? Are other aircraft in consideration, or is it in general a bad idea? Why?