texts: What pattern of position lights did early Soviet jetliners use?

texts:
All aircraft that operate at night or in poor weather need position lights to make them visible to other aircraft for the purpose of avoiding mid-air collisions.  On most aircraft, these follow a set pattern: two continuously-illuminated lights on the wingtips (red on the left wingtip, green on the right [a pattern inherited from marine navigation lights], to allow other aircraft to see whether yours is flying towards or away from them), a continuously-illuminated white light in the tail, and high-intensity white anticollision strobe lights on each wingtip, in the tail, and on the upper and lower surfaces of the fuselage.
However, according to the Wikipedia article on the Ilyushin Il-62, early Soviet jetliners did not follow the standard arrangement for position lighting:

The Il-62 entered Aeroflot civilian service on 15 September 1967 with an inaugural passenger flight from Moscow to Montreal, and remained the standard long-range airliner for the Soviet Union (and later, Russia) for several decades. It was the first Soviet pressurised aircraft with non-circular cross-section fuselage and ergonomic passenger doors, and the first Soviet jet with six-abreast seating (the turboprop Tu-114 shared this arrangement) and international-standard position lights.  [Emphasis added.]

What arrangement of position lighting did pre-Il-62 Soviet jetliners use?


texts: How to read SID/star procedures and visualise them?

texts:
I plan to make a software to show the flight passage from take off to landing. I have worked on GIS software & now I'm searching for more info about NAVIGATION PROCEDURES. I'm trying to visualize SID/Star procedures and display them in a GIS software. I'm a software engineer & have no experience in aviation and navigation.
Q1. Is there a quick and simple way to learn how to read  NAVIGATION PROCEDURES for an aviation newbie like me ? Such as a website, article or tutorial.
Q2. Is there a free software to display navigation procedures? I have tested Little Navmap, I found that it couldn't display the procedures accurately as shown in Charts.
Q3. Is there any open source software library for displaying those procedures which can be used beside a GIS sofware? In fact is there a solution to import those navigation procedures through a GIS software?


texts: Why did Boeing choose to give the Boeing 720 such a designation?

texts: The Boeing 720 was a modification of the Boeing 707. Why was it given the unusual number of "720" instead of a "707-xxx" or "7x7" designation?


texts: When replying to ATC, callsign first or last?

texts:
When I was in flight school, some instructor told me that it is the unknown ICAO standard that you should reply to an ATC call with your callsign first, like this:

"XYZ123, climb FL350"
- "XYZ123, climb FL350"

But I only know one airline that operates like this. In all other parts of the world, I hear:

"XYZ123, climb FL350"
- "Climb FL350, XYZ123"

So can someone tell me the definite ICAO standard on that and where it is written down?


texts: Flying Considerations during an Eclipse?

texts:
August 21, 2017 will see a total eclipse of the sun across large sections of the United States, generally between about 10a.m. and 2p.m. (depending on location and timezone)

If one is flying during the eclipse, are there considerations, other than sudden transitions to darkness and then to light, that should be taken into account?

Do Pilots flying during this time need to be Night Current?
Can time logged during the eclipse be logged as Night Conditions?


texts: What are some specific benefits of cryogenic wind tunnels?

texts: What are some benefits to using a cryogenic wind tunnel over a more traditional one? Are there certain aerodynamic properties or principles that are better studied at low temperatures?


texts: Do Blue Angels jets have a snap-to-angle feature in their control sticks?

texts:
So, in most drafting/modelling software, we have a feature called Snap to Angle or Snap to Edge; its function is to snap the control(cursor) to the nearest most obvious angle/edge to relieve strain on operator to carefully move the cursor to that exact point.
If you haven't seen it try Right Click on Desktop > View > Align Icons to Grid & then move the icons around.

Now on to my question:
When performing the maneuver Opposing Knife Edge it is crucial that the roll angle (w.r.t. level) should be very close to ±90°.

Especially considering the high speed (& probably high G-Force) situations is a feature equivalent to CAD's Snap-to-Angle employed in air-show modified jets?


texts:
I am from Bangladesh. Bangladesh has EASA 147 approval.

Is EASA B1 equivalent to DCAM B1?
Will Bangladesh accept the license?
If I want to convert the DCAM license to EASA license what do I have
to do?
About type training, from which country should I get the training?


texts:
Someone help me understand this thing in a simple way.
I understand it helps determine Vx.


texts: Aborted take off due to not closed cargo doors. How this will be signalled?

texts:
A hypothetical situation (I know that it is very unlikely to happen in real). When closing cargo doors, a piece of fabric from the luggage carrier's uniform stick in between. The cargo door is actually closed (no real danger), but the latching sensors are sending a misleading signals.

How this will be communicated in the cockpit? What visual or audio signal will be used / emitted in the cockpit to inform the crew about the reason? Is there any specific light or button as an endpoint for cargo doors sensor? Is there any specific sound?

How will the crew communicate to the tower the reason for an aborted take off (what kind of message, who will do this -- flying pilot, non-flying pilot)?

Clarification: This question is for the sake of the story that I am writing. It (both story and the question) involves Boeing 777 taking off from LHR in August 2014.

Aborted take of is due to a misleading information coming from cargo doors' sensors that reveal a possible problem only during take-off, not before (i.e. during taxi). The doors are actually closed (no real danger posed after check). But there's a tiny piece of fabrics from cargo loader's uniform stick in between doors. This question is a follow-up or alternate version of this question. Here I'd like to know what happens, if such situation will be detected before V1. In linked question I am asking about the same situation detected after V1 or shortly after take-off and thus after such aircraft returns safely to the airport and clears the runway.

I am aware that most airline experts will say that such situation is not possible at all. I am, on the other hand, a system designer and I know that such "ghost" situations of "neither 0 nor 1" sometimes do happen. But, for the sake of this question, if you feel uncomfortable with such reason -- let's assume that take-off was aborted due to any other reason, i.e. engine failure. I belive that such reason has similar severity as the need of checking whether cargo doors are really closed due to fact that on-board computer provides misleading data.

I'd lilke to underline that this is purely hypothetical question. I am aware that while such questions are sometimes hard to answer, they're in general quite welcomed in this site and are not off-topic.


texts: Does thrust output in jet airplane remains constant when altitude increases?

texts: I’m a noob so sorry for my ignorance. The question is: do we need (in jet airplane) to increase the throttle to maintain constant thrust output if we want to fly higher (not considering climb phase), I mean whether on 2000 ft and 20000 ft altitude throttle is in the same position or we need to push it forward if we fly at higher altitudes to maintain constant power (as in piston airplanes).


texts: What is the difference between HFEC and LFEC inspections?

texts: Sometimes we have to do High Frequency Eddy Current (HFEC) or Low Frequency Eddy Current (LFEC) inspections. My question is: what are the major differences between these two types of inspection? Which one is preferable and more economical? Which type of inspection is required in which cases?


texts: Is it technically viable to reintroduce sleeping berths?

texts:
The airlines are always trying to jam more passengers into each plane. I'm smaller than today's average, and I'm still often uncomfortable in a standard Economy seat.

It occurred to me that in the current design, there's a great deal of space wasted over the passengers' heads. And that many of us passengers already do our best to sleep through flights.

Hence my question: Is there any reason an airline couldn't introduce a cabin in which some or all passengers travel in a reclining, rather than sitting, position? Seems to me that  it would be more comfortable (except for claustrophobes and those who really need to work during the flight). The enclosed space would inherently reduce some of the risks of passengers being thrown around in turbulence or an emergency landing; safety belts (or cargo restraint webbing? I'm not sure I'm joking) could handle the remaining risk.

No, I don't really think it would be commercially viable ... but I'm wondering whether folks who actually Know Something about aircraft safety and loading think it's technically viable.


texts: Can a civilian purchase a new (Not Retired) fighter jet?

texts:
Let's take a jet like the F22 for example. Strip all the classified systems/weaponry out of it (civilian wouldn't need that), and just leave the basic aircraft itself.

Could a civilian technically purchase this aircraft for personal recreational use/travel? Or are these exclusively contracted to the military? How does that work legally/technically? I've always been curious.

There are multiple cases of wealthy civilians purchasing USED fighter jets, sure, but I'm talking about a wealthy civilian who can afford it ordering a shiny new (not retired, there is a difference) personalized, non-armed F22 for personal use. Is that even a legitimate premise?


texts: How do military fighter aircraft identify themselves and each other?

texts:
I live in an area where there is much NATO military activity. Often there are various fighter aircraft fly-overs. But none of the common websites such as flightradar24, flightaware and planeflighttracker etc. used for identifying aircraft using ADS-B and ACARS etc, are able to "see" them.

So apart from ground radar, how does the military aircraft identify themselves?
Are there other type of transponders used in these?
Has there been any known attempts at building some amateur radar network to track these unidentified aircraft?

There was little useful information in this SE answer. I also found after posting a very similar SE question and answers. However, it still doesn't fully address the questions.

EDIT: As an update for question (3), there seem to have been some success on using SDR's as passive radars, as shown in these links:

http://www.rtl-sdr.com/building-a-passive-radar-system-with-an-rtl-sdr/
http://www.rtl-sdr.com/tag/passive-radar/
http://www.kaminski.up.lublin.pl/RTL-SRD.html
http://hackaday.com/2015/06/05/building-your-own-sdr-based-passive-radar-on-a-shoestring/


texts: There are very large wind tunnels out there. Wouldn't it be very efficient to test new airplanes flying them "on the spot" inside of these tunnels? That is, in free flight - not mounted to a pylon? One could presumably omit the test pilot and remote control them, get excellent visual feedback and have a completely controlled environment. Has this been done? If not, why?


texts:
I recently saw a very interesting documentary film made in 1980 about a narrowly-averted airline disaster in which the flight crew were incapacitated and a retired pilot, with the help of other crew members and experienced ground controllers, managed to land the plane safely.

The aircraft in the film is a 707, though I was puzzled by some of the interior shots, in which I thought it looked much more like a DC-8 (it's been a very long time since I flew in either). The footage of the cockpit was actually quite baffling, and I really didn't recognise it at all.

What exterior and interior features would help identify the particular 707 variant?

The documentary is apparently quite famous, so perhaps someone even knows the tail number. It's simply called Airplane! - very informative, and I learned a great deal about the aviation - highly recommended.


texts: What do these double Class Bravo airspace floor and ceiling limits mean?

texts: While browsing SkyVector I came across these double Class B airspace limits within the same section (is that what you call it?). I'm wondering what it means and what the difference is between this and FL145/SFC.


texts: Navigate to the final approach course after radio failure under IFR

texts: What would ATC expect the pilot to do if, at the position marked below by the red X, the aircraft lost radio communication and was on a radar vector heading 250 degrees at/assigned 3000 msl and the pilot was told to expect the ILS approach to Runway 7 Right? Assume the IFR aircraft did not have DME, RNAV or GPS equipment and the weather was IMC.


texts: Should people flying UAVs be called "Operators" or "Pilots"?

texts:
I'm wondering if there is any formal/official definition* pertaining to the title given to people controlling Unmanned Aerial Vehicles? Are they "more" correctly titled Operators or Pilots?

*As set by ICAO, EASA or FAA for instance.

Examples:

The Guardian: "Life as a drone operator"
Air Force Times: "Enlisted drone pilots? Decision expected early next year"

I've had a look through EASA Directive 2009/48/EC where it states:

  Operator shall mean any legal or natural person, operating
  or proposing to operate one or more aircraft;

That does not provide a distinction between the entity organizing (e.g. airline) and the actual person doing the flying. A commercial pilot will not title himself an "aircraft operator" but will call themselves a pilot. This is less well defined with UAVs.


texts: What pilot certificates were needed to fly the Space Shuttle?

texts: Were there specific FAA (or other relevant regulatory body) pilot licensing or certifications required to fly the Space Shuttle? Are they specific to the Space Shuttle, or would it have fallen under an existing pilot license scheme?


texts: How long does the gear extension/retraction takes on the ATR-42?

texts:
Which is typical time of landing gear extension in normal conditions ? I would like to know it especially for the ATR-42 but any other typical value is welcome !
Furthermore can you provide any link to data sheet for ATR-42 technical data about landing gear ?


texts: Can you fly 2000 miles on an engine that costs less than $500k? If so, what type of engine?

texts: Ok so Im exploring ways to bring cargo and medical supplies to various rural cities in say Africa without relying on ground infrastructure. Just short and cheap runways spread around the continent. It seems any type of VTOL plane wouldn't have the range. Electric is also out. It also seems like piston planes don't have the range, while turbojets are millions of dollars. What about used turbojets? Whats stopping piston engines from flying longer?


texts: What precautions should be taken when flying near the magnetic poles?

texts:
Aerial navigation is designed to primarily use magnetic headings. Consider an international flight which flies a great circle route across the North Pole, or an aerial tour around the Atlantic area. What should the pilots do to avoid getting lost?

This question asks about VOR alignment, and this question discusses the coordinate system used; but neither discuss what the pilots should do in the cockpit. How do you align the HSI? And what happens if GPS has malfunctioned?


texts: Why is thrust said to be constant over speed for a jet engine?

texts:
I'm just interested in some basic facts regarding flight. On reading the rather "low level" book "Understanding Flight, David F. Anderson, Scott Eberhardt), I recently came up to the following diagram:

Why is thrust approximately constant with speed for a jet engine? Everything gets mixed up in my head as follows:
Thrust is approximately $F_t=\dot m \cdot \left( v_{gas}-v_a\right) $, where the speeds are outlet speed on the nozzle and true airspeed, respectively.
https://en.wikipedia.org/wiki/Turbojet#Net_thrust
So there are really a lot of parameters. What of them are assumed to kept constant in the right diagram and what are changing? Without that information, the diagram seems meaningless for me. For my naïve opinion, a change of thrust is controlled by changing the thrust lever and thereby changing the fuel content within the combustion chamber. Lets say the lever is at its max or a fixed position (whatever this means). Then while increasing speed the factor $v_{gas}-v_a$ gets smaller, assuming the outlet speed is constant.
So to have still the same thrust there are three possibilities':

outlet speed increases
mass stream increases
both of them increase

I can imagine that mass stream increases "somehow" with airspeed (keeping fuel injection constant), so there might be some cancellation of the speed factor. .But is this the whole story? Why is it canceling completely?
On writing this question another question arises:
Considering an ideal engine without losses, total power is
$P_{tot} = \frac{1}{2} \dot m \cdot (v_{gas}^2-v_a^2) = \frac{1}{2} \dot m \cdot (v_{gas}-v_a)(v_{gas}+v_a) = \frac{F_t}{2}\cdot (v_{gas}+v_a)$
Lets say, the power lever is on a fixed position. Is this position an indicator for the total power of the engine? In other words: is total power to the engine constant, when the lever is on a fixed position? I ask, because when assuming constant thrust this formula would mean, that total power (as well as propulsive power) must also increase, because at higher TAS of the plane, gas outlet speed would (up to my poor understanding) rather increase instead of decrease. So what happens, when the thrust lever is on a fixed position? Could it be, that there is a governor behind, taking control of thrust? In this case the right picture has no meaning at all, because while increasing TAS the governor automatically injects more fuel.
There are so many questions and in fact no understanding of anything...


texts: How does security and baggage checking work in regards to a private jet?

texts:
I was told recently that if you are flying on your own private jet, you can drive your car directly on to the runway, park next to your plane and board without any security checks.

This can't be true can it?

I don't own my own private jet so I'm afraid I can't check for myself.

How does security work around privately owned planes landing in public airports?


texts: What is the purpose of the three cylinders under the engines of the Junkers 52?

texts: They're mounted underneath each engines on the JU-52. I saw them up close at the museum. Each one consists of bundled half-inch pipes running through the whole length, open at both ends.


texts:
This comment to a question about underwing vs rear-mounted engines notes the existence of a rarely used third option: overwing engines.

There seems to be very few planes using those. What are the disadvantages that makes it so unpopular, and what are the advantages that made it worth building those few planes?


texts: Why does the UK CAA restart its page numbering with every new chapter of their CAP publications?

texts:
Every CAA Publication (CAP) seems to restart its page numbering when starting a new chapter. Does anyone know why they have decided to do this?
For example, the CAP413. Instead of a logical page number ordering throughout the document, you have to reference it as chapter 4, pg 4 or chapter 5, pg 2.
It makes it very difficult to reference information to others. It also makes navigating as a PDF challenging - many of the CAPs are solely in PDF format. (Often you can only view one page at a time, and it is so easy to get lost in a document which restarts its page ordering).
Is there a reason why the CAA has done this? What would be the formal or best way of referencing a CAP page?


texts: How does a hot tip-jet supply fuel to its engines?

texts: Some tip-jets move their rotors by running jet engines on each end of the rotor. Obviously there must be some ways to supply fuel to those engines through a rotating body. How is this accomplished?


texts: If an airline cancels an aircraft order, can a different airline acquire those options?

texts: Let's say Airline A placed an order for an aircraft a while back. After a bit of time, Airline A decides it no longer has a need for the aircraft and decides to cancel the order. Meanwhile, Airline B decides it wants to buy said aircraft but doesn't want to go to the back of the delivery line. Is there a process where Airline B can take Airline A's spot in the delivery queue? I vaguely remember seeing something like this happen before, but cannot find any sources.


texts: How did jet engine aircraft perform compared to the best reciprocating engine aircraft during WW2?

texts: How did the performance of jets in World War II compare to the cutting edge propeller planes (e.g. P-51, Zero's, etc) of the day?


texts: Why do most A320s make that distinct scream on takeoff?

texts:
I've noticed that the engines on the A320 make a very a distinct sound on takeoff. Is there something about the CFM-56 series that causes this?

This noise can be heard in this video.


texts: Why is a large flashing "X" placed on a closed runway at Reagan National Airport?

texts:
Runway 15 at DCA (Reagan National) is closed at night and other times. By "closed," I mean that airport management places a gigantic lit/flashing "X" in the landing zone of 15. I'd estimate the big "X" is 8 by 8 feet, at least. It's like one of those roadside trailer flashing signs, except it's a runway.

The flashing X is very evident to pedestrians, bikers, etc., on the Mount Vernon trail. It's not some bizarre national secret.

My question: Why, in the tightly controlled airspace of Washington, DC, would DCA need to roll out a giant lit "X" to keep planes from landing there?

As if the obstruction were not there, you could fly in? That doesn't calculate, given how tight the airspace is controlled.

Why does this airport in the center of the world's highest airspace security roll out a construction trailer with a big X to keep planes from landing there?


texts: To determine wing loading, do you need to subtract the weight of the wing from the gross weight?

texts:
Is it true that I must subtract the weight of my ultralight wing from the gross weight of my airplane inorder to determine the wing loading of my ultralight airplane? If yes,why is this so?
I read a pdf sometime ago stating that the weight of the wing is negligible when determining the wing loading.


texts: What's the correct ATC phraseology to enter a nonpublished hold?

texts: Before entering on a hold (stack), the ATC should instruct the turns and headings to be accomplished by the crew.  If it is not printed on the charts, as on STARs, what is the correct phraseology to be used by ATC?


texts: Per the AIM, Helicopter pilots may fly non-copter approaches at half the published visibility. Where is that in the FAR?

texts: In AIM 10-1-2 Helicopter Instrument Approaches, paragraph a1 says the visibility reduction rule comes from 14 CFR Section 97.3. From what I can see, that section is just definitions. What is the AIM referencing?


texts: How is the Cessna 172S G1000 Electrical System powered?

texts:
Why, on a Cessna 172S, there is a positive voltage reading on the Main bus when only the standby battery switch is on? In the checklist it says

  verify M BUS Volts are 1.5volts or less.

I thought that the standby battery was supposed to power only the essential bus.


texts: How much does the design, implementation, test and certification of a Passenger-to-Freighter Conversion cost?

texts:
This question answers how much it costs to convert a given aircraft from passenger to freighter once the STC is approved by the FAA. How much does it cost to obtain the STC in the first place?
If this data is not publicly available, would there be a generic way to estimate the cost of such a conversion?

Related Question:
From what I've found the required design and analysis is primarily focused on the modification of the aircraft structure (as opposed to e.g. flight controls), and to some extent related to the avionics that monitor the health of the various onboard aircraft systems (e.g. ensure that no warnings/errors are displayed to the flight crew as a result of the absence of the passenger entertainment system).
Does that imply that the cost to generate the certification basis for the initial conversion would be fairly comparable across different aircraft? I realize that the labor of the actual conversion (once approved) will differ based on the size of the aircraft.
By way of example - how much would the required analysis differ between the cargo versions of the CRJ-200 and the B737-800BCF?
Cargo Version of the CRJ-200:

Cargo Version of the 737-800:


texts: Boeing worked its Supersonic Transport (Boeing SST 2707) design in the 1960s. They gave it the number "2707". Why was this aircraft given that number? Did it have some significant inside-Boeing relation to the B707 or was it just some number that followed another Boeing numbering scheme?


texts: Why does an aircraft as big as the Airbus A400M use turboprops?

texts:
Why is it that a plane as big as the C-17 (the A400M is slightly smaller though) use turboprops instead of turbofans? Both aircraft seem to have the same purpose and are both capable of landing at short runways. So why does the A400M have turboprops?

I want to know why two very large planes have different propulsion systems.


texts: How does an increase in climb rate affect climb gradient?

texts:
I'm learning to take (and pass I hope ;)) my PPL exam and I've just found one question, that I'm not 100% sure about.
How is climb gradient going to change (for small angles) while rate of climb increases 2 times? (TAS = constant)

a) stay the same
b) increase 2 times
c) increase 4 times
d) decrease 2 times

Can I calculate climb gradient as (rate of climb/TAS)? If yes, the correct answer is B.
Guys, could you please confirm?


texts: Do airports charge airlines for extra time spent on ground due to weather conditions?

texts:
I heard somewhere that airlines pay the airport depending on the time spent at the gate. Suppose there are weather conditions that cause the aircraft to be delayed at the gate, such as heavy rain lasting few minutes, snow requiring half the runway to be closed to remove the snow, and so on.

What happen in those exceptional conditions? Does the airport still charge the airline for all the time spent at the gate? Is there special tariff for exceptional weather conditions?


texts: Why battery voltage is lower than system/alternator voltage

texts: I’m a noob in electricity so pardon for my ignorance. Why the battery voltage is always lower than whole system and alternator voltage (considering light aircraft electrical system). E.g. In Cessna 150 system voltage is 14 V and battery voltage is 12 V, in C152 system and alternator voltage is 28 V and battery voltage is 24 V.


texts: What is the difference between RFL and ECL in Air Traffic Control?

texts: There are two messages to change the Flight Level: RFL and ECL. However, I don't know the differences. Can anyone explain them?


texts:
FAA databases list multiple Official Facility Names with a given Associated City Name, for example:

  CITY: Fort Lauderdale
  FACILITY NAMES: Fort Lauderdale/Hollywood International (FLL); BSO Public Safety Helistop; Port Everglades; Broward Health Medical Center; Fort Lauderdale Executive (FXE).

Only FLL and FXE are airports. The rest are heliports. Are there airport identifiers assigned to heliports?


texts: How are IAS to CAS conversions calculated?

texts: How do I calculate calibrated airspeed (CAS) from indicated airspeed (IAS)? For example, how is 600 knots indicated calculated to 595 knots calibrated?


texts: Is the Dassault "ministop" related to the Dunlop Maxaret ABS?

texts:
Dassault fighters e.g. Ourargan and Mystere had Anti-lock devices called "Ministop" on main landing gear brakes.
Anybody has a picture / drawing / detailed description ?
Is the Ministop related to the Dunlop Maxaret ABS ?


texts: I've been denied VFR clearance through C airspace, what should I do?

texts:
If I'm flying along in my C-152 and I am trying to go in a straight line through the "center" of C airspace (to land at a regional airport under the airspace), but the controller tells me to remain clear, what should I do?

Would it be safe to fly under the C, or above it, or would it be best to completely circle around even if it takes extra time and fuel?


texts: How do Throttle control and Propeller control work together?

texts:
I haven't been able to understand.

If propeller control controls the pitch of the blades in a constant speed engine, what do the throttle control do?

I've seen (in some normal operation manuals for some planes) that you have a Torque limit and control the Torque with the throttle control, and the RPM with the Propeller Control, but, if the propeller is spinning always at the same speed and the blades are positioned at the same pitch how can the throttle reduce or increase thrust?


texts:
Can endplates be used to reduce chord length by up to 14%?

I understand large endplates can change the lift distribution from an elliptical one to a uniform one, making the wing more efficient by increasing lift near the wing tips.

This increases the effective aerodynamic span by up to 16% ( see pic below ).

pic: Effect of large endplates on a short span wing, Source: Zenith

Can this be used to shorten the chord?

eg.

16' span, 2' chord, total wing area: 32 sq ft rectangular wing.

Use large end plate, h/b=20%.

revised effective aerodynamic wing span: 16' x 1.16= 18.5'

Revised chord: 32 sq ft / 18.5 = 1.7' chord.

Is this correct thinking?


texts: How to keep a helicopter steady when close to the ground?

texts:
I understand the ground effect and the air cushion of approximately 3-6 inches when the helicopter is close to the ground. With that in mind, my questions are:

Why does the helicopter become inherently unstable when close to the ground?
What are some methods to keep it smooth when operating close to the ground?


texts: Why some WWII fighters still have fabric/wood control surfaces?

texts: I've heard people say that the reason US in WWII preferred designs with fabric control surfaces with either a metal or plywood frame is they can sustain some small arms fire without disintegrating. Is this really the reason? Or is it simply weight saving?


texts: What is the effect of aileron deflection on the centre of pressure?

texts:
Deflecting an aileron will increase or decrease the camber of the outer wing where the aileron is attached. I learnt on this platform that centre of pressure (c.p.) moves fore and aft with aileron deflection.

Is the c.p. movement as a result of aileron deflection significant?
If it is significant, how does one calculate the difference in c.p. with respect to aileron upward or downward deflection?


texts: What factors should be included when calculating hourly aircraft operating cost?

texts:
I'm working on a budget for operating an aircraft and trying to better understand the hourly operating costs.  What factors should be included that are often forgotten?

Although this is partially discussed here I'm interested in distinguishing between general cost of ownership (hangar, insurance costs, etc.) with items specific to hourly costs. And I'm not looking for actual numbers - just the categories to consider.

Obviously this list will depend upon the type of aircraft, but to keep the question somewhat general, I'm interested in a light single-engined piston aircraft.

So far my categories include:

Cost of fuel per hour
Engine reserve per hour
Prop reserve per hour
Oil cost per hour


texts: What kinds of jobs could a senior in high school get at a small local airport?

texts: Is there anything a senior in high school could do for a small regional airport in Utah?


texts:
From the question about sharp pods under airliner wings, I think the right term is anti-shock bodies, or flap actuators/track fairings.

What's the little antenna looking thing extending off the rear end of it? My best guess it something anti-static? Why are they necessary?

I should add that this is an American Airlines Airbus 321.


texts: Does total aerodynamic force include skin friction/shear streses contribution?

texts: Does total aerodynamic force by definition  include skin friction/shear streses contribution or this only represent overall intergration of static pressure(normal to surface) around wing/airfoil?


texts: Does Qantas have an above-average safety record?

texts:
There is a widespread belief, at least within Australia, that Qantas has, or had, an above-average safety record. For example, AirlineRatings.com recently listed Qantas as the world's safest airline, which was reported on by the Australian Broadcasting Corporation and Fairfax Media. Personally speaking, it seems like aircraft incidents with Qantas or JetStar get more coverage than those involving other airlines, but I can't verify that.

I'm skeptical of the belief that Qantas has an above-average safety record, let alone being the safest airline in the world.

From the Wikipedia article List of Qantas fatal accidents, I know that Qantas hasn't had any fatal jet airliner incidents, and the last accident it had was in 1951. However, I don't know whether aircraft accidents are so rare that an airline can have a better average than others because of chance alone.

I'm not doubting that some countries have safer airlines than others. If offered the choice between Qantas and Air Koryo, I'd definitely choose the former. I also don't doubt that some countries are safer to fly in than others - for example, planes in Australia don't have to deal with snow very often. However, I don't expect that to be a major factor. So I'm ultimately interested in a comparison between Qantas and airlines from countries that are comparable to Australia.

Did Qantas have a perception of having an extraordinary safety record before the 1988 movie Rain Man, where the titular character said that Qantas never crashed?

Is there enough data to say that Qantas is the safest airline in the world, or even say that it's safer than similar airlines, such as the ones Raymond refused to get on in the movie?


texts: What are these wheel-chocks made of and what color do they most probably have?

texts:
I found a new hobby of mine: Colorizing black and white photos. My first project was a B-17 and now I'm working on a He 162 Volksjäger. The plane is on ground and fixed with wheel-chocks.

Now the question is what they are made of and what color they could have. Maybe there is a specialist for german aviation in WWII out there.


texts: If the efficiency of a turbofan engine is 35%, where does the rest of the fuel energy go?

texts:
There have been a couple of questions on this site about the efficiency and propulsive power of turbine engines (here, here, here).

In a high bypass turbofan engine, what are the losses in the different stages? Where does the unutilised energy go, and what exactly is left over to make the aeroplane fly?


texts: Difference between constant speed and variable pitch propellers?

texts:
Here is how I currently understand constant speed and variable pitch propellers.

In constant speed propellers, the pilot controls the governor via the prop control knob and the speeder spring, flyweights, and other parts of the system act accordingly to increase or decrease the amount of oil entering the propeller hub. This automatically changes the blade pitch in order to maintain a certain engine RPM, even in an over speeding or under speeding condition. Setting the engine at 2300 RPM will keep the engine at 2300 RPM at all phases of flight even if no adjustments to the blue knob are made.

In a variable pitch propeller, the pilot adjusts the pitch via the prop control knob for different phases of flight. However, the blade pitch doesn't automatically change in order to maintain a certain engine RPM. The pilot would need to adjust the prop control in under speeding or over speeding conditions. Setting the engine at 2300 RPM will not keep it at 2300 RPM if climb or descents are made without adjustments to the blue knob.

Is my understanding of both kinds of propellers correct?
Are the flyweights only found in constant speed propellers? Are there any other parts in the system that can only be found in constant speed propellers and vice versa?


texts: What is this hole above the intake of engines of Mil helicopters?

texts:
Almost all the helicopters designed and manufactured by Mil have a hole above the intake. e.g.

What is it for? APU? Other helicopters made by this company:


texts: What does 'EST' at the end of a NOTAM's valid time mean?

texts:
In this NOTAM below, the valid time is "2006280446-2007312359EST".
EST does not appear in the FAA NOTAM contractions list.

I assumed this EST meant "Eastern Standard Time", but that conflicts with the information shown below in ForeFlight.
This is what ForeFlight shows for the same NOTAM:

What does this "EST" mean?


texts: On an engine failure, can I contact the tower instead of 121.5?

texts:
Let's say I am cruising at a very high altitude with my Cessna, like at 5000ft+ AGL, and I got an engine failure.

After going through the checklist, my engine is still not working, but I realized that I could easily land the airplane on an airport near me with my gliding speed.

Can I just talk to the airport, whether controlled or uncontrolled and take whatever runway is best for landing, instead of declaring an emergency on 121.5 and squawk 7700?

Thanks.


texts: Does ATC have to maintain separation on diverging aircraft?

texts: Say you have an eastbound flight at FL210 that wants to climb and a westbound flight on a converging track at FL220 that wants to descend. There's the minimum required 1000 ft vertical separation. Once the planes have passed each other can ATC clear them to climb/descend right away or do they have to wait until they are 5nm apart before they can break the vertical separation? And what about TCAS? Would it consider that a conflict?


texts: What is the device at the tail of the F-16 Block 60?

texts:
The F-16 Block 60 has a lot of advancements, one of which is the device at the tail. What is it?

For clarification, I believe all these vents (second image) are for said device.


texts: How does one calculate the Mean Geometric Chord in extended Trapezoid Wing?

texts: The general formula to calulate MGC of a wing is given for a trapezoid in many books but there isn't an example showing how to calculate it for a wing shaped like the one below. I tried to solve individually for section 1 and section 2 and take the mean between those values but couldnt get the solution. I just want to derive a simple formula in case the wing looks like this.


texts: Do some aircraft lower the landing gear mid-flight?

texts:
Are there situations in which a pilot could/has to lower the landing gear during flight for reasons not directly connected to landing? (i.e., not part of the landing checklist)

Originally I thought I had seen some around the location indicated by the pin on the map below (17° 25' 30.093" N,  78° 32' 27.4734" E), in the evening time around 4:00  and the weather was clear.


texts: How long will it take a new pilot to start flying more advanced planes like a Cirrus SR22T or Piper Malibu?

texts:
Here is my scenario.   I'm 53 years old and getting ready to sell my business and retire.  I've always been fascinated with aviation and have done lots of research and taken multiple training flights.

What I keep reading is "match your plane to your mission".  Makes sense.  Here is my mission.

I live in Kansas City and would like to fly to a second home approximately 900 miles away.  Also visit kids, vacations, etc.  Most flights in the 400-1,000 mile range.

Plan is to start my PPL once the business sells and I can commit to two-three lessons per week.   Hopefully get my PPL in 60 hours or so, then start on my instrument rating.  Another 50 hours for that appears to be typical.  As such, instrument rated with 100-120 hours logged within 12-18 months.

For my typical mission, something like a TTx, SR22T or a Malibu sound appealing.  Pressurization would be nice.  I don't see myself flying a 172/182 900 miles comfortably.

I figure I will be flying by myself 50% of the time.  With a second person 25% of the time and with a third person 20% of the time.  Only rarely with 4 seats occupied.  Budget around \$700K to max \$1M.

What is a realistic path for me? At what point is it reasonable for me to safely and legally pilot these high performance planes?   How would you suggest I get from newbie to mission capable?

Thanks!


texts: Do pilots need to know how to use a sextant?

texts: Can a sextant be used while flying? How accurate/reliable is a sextant, both standing still and at 500+ mph? Are sextants found in any cockpits today?


texts: Why does the door slide mode need to be changed after the jetway or stairs are detached? Does the mode only need to be set when the door is closed?


texts: Why does the Falcon 900 have anhedral wings?

texts:
Why does it have anhedral wings and not "normal" wings? Many other similar aircraft with low-wing have dihedral wings.

Source: DassaultFalcon.com

Edit: This is about the Falcon 900, which apparently has a low-wing design and it's not used for cargo like the An-225


texts:
The short BBC news item and video The drone designed to fly on one propeller shows the flight of something that looks like quadcopter missing three of its propellors and motors. It continuously rotates around a vertical axis through its center of mass tilted at perhaps 30 degrees, and the single propellor can provide different lateral thrust in different directions by (I assume) quickly modulating its power throughout the rotation cycle.

This seems to be only a demonstration of an interesting effect at this point in time, but I'd like to understand how it can retain both stable position and attitude with only one degree of freedom (speed). Yes the attitude is rotating, but that motion appears constant.

So far I haven't found anything to read about how this can actually work. In the video there is a suggestion that this has been calculated and equations are briefly flashed on the screen.

The work is done at ETH Zurich and the Flying Machines Arena.

How can this single-prop drone maintain stable (rotating) attitude and position?

I'm also curious if this is a 'new' effect, or is this a version of something that has been previously demonstrated or at least discussed.

above: GIF made from screenshots of BBC video found here.

above: Screenshots of BBC video found here.


texts:
After hernia surgery, what do I need to do to be cleared to exercise the privileges of my PPL?

I recently had hernia surgery in the past few weeks and just had my follow-up appointment with my surgeon yesterday. A week or so ago, I called the FAA Medical Hotline to self-report on my condition and was told that I was grounded until I received a doctor's notice clearing me for normal activity.

The research I've done shows that I need to submit a doctor's letter and an operative report to the FAA to be considered medically eligible again.  My doctor's notice from my recent appointment says that I am cleared to return to normal activity on 1/31/20. Is this sufficient for the FAA to clear my grounded status?


texts: What is that invisible bump in the air called that occurs after completing a 360 degree turn?

texts:
Does that bump you feel after completing a level 360 degree turn in an airplane have a proper name? I've heard it called an "attaboy bump", but obviously thats not a proper name.

My understanding is that the bump occurs when a properly executed level 360 turn overlaps the disturbed air caused by the same aircraft's flight path into the turn.


texts: What is the difference between the red and black box identifiers on UK airport charts?

texts:
On UK airport charts like the one below for Manchester (EGCC), what is the difference between an identifier with white lettering on a red square and one with yellow lettering on a black square with a yellow outline?

(eurocontrol.int)


texts: Can small children be seated away from their parents/guardians on a flight?

texts:
I am interested if there is any law or regulation which prohibits carriers from seating children in a seat not adjacent to their parent/guardian?

I am flying with a group of 17, which includes 2 infants (without allocated seats), but seven children ranging in age from 2-5. We opted not to pay the extra charge to pre-allocate seats, and the airline has allocated us seats spread around the aircraft in a configuration which does not allow an accompanying adult to sit next to a child.

I was sure there was some air law which prohibited this on safety grounds, but have been unable to find it.

This question relates to the EU, but answers regarding other jurisdictions welcome.


texts: Why does obstacle clearance area splay outward instead of being a rectangle?

texts:
I am having trouble figuring out the logic behind the way that obstacle clearance areas are constructed. Take, for example, a departure procedure where Initial Climb Area is defined in TERPS (section 14-1-6) as a trapezoid:

Even as far as subsequent segments are concerned, their respective obstacle clearance areas seem to follow the same pattern, like this example from TERPS:

Why is this happening? Is there a reason that at the beginning of each segment the obstacle clearance area "shrinks" and then splays outward? Especially when one considers SIDs with really lengthy segments, where near their end the aircraft's perpendicular distance from OCA's borders is huge. It would seem more reasonable to me if the obstacle clearance area was a rectangular region, as it is the case with STARs:

Could someone point me in the right direction?


texts: What is the first fighter jet which was built with twin engine and tail configuration?

texts: What is the very first fighter jet that pioneers the twin engine and twin vertical stabilizers over the engine just before the exhaust (like the F-14, F-15, F-22, Su-35, etc)?


texts: Military paintjobs matte for airshow also?

texts:
Combat aircraft are painted in a matte paint to prevent them from reflecting moon/sunlight too much.

But what about liveries used for airshows? Those colorful paintjobs, are they also always matte, or are they sometimes painted in more shiny paint.


texts: Is it possible to modify an AV-8B Harrier II to a supersonic aircraft by applying some modification?

texts:
Is it possible to convert McDonnell Douglas/BAe Systems AV-8B Harrier II Plus into an effective and usable supersonic aircraft?

May be, by changing the engine or applying some modifications on the air-frame...


texts: Regarding 49 CFR 830, what is considered an in-flight fire?

texts:
49 CFR 830.5 requires immediate notification for in-flight fires.

Does that mean there must have been visible plasma?  Would the presence of smoke alone be enough to report that there was a fire, or would something that simply smolders not meet the standard of an in-flight fire?


texts: Should I log flight time as a passenger?

texts:
If I only have a private pilot license, and am not the pilot in command, should I log my flight time?

If so, what are the limits of this? i.e. is that as true in the backseat as it is in the front seat? Must I have that type rating?


texts: What jobs are available for a person on the autistic spectrum with ADHD?

texts: For a young man who has Autism and ADHD and considered high functioning ( cognitive and processing difficulties but very social ) what types of " hands on " jobs are there for him in the aviation industry?


texts: Could Malaysia Airlines Flight 370 have sunk without leaving any floating wreckage?

texts:
With all the searching on the surface of the Indian Ocean for evidence of Flt. 370, I'm wondering if there's any conceivable scenario in which the Boeing 777 could have sunk without producing any floating wreckage.

Is it possible for a 777 or similar model to hit water without leaving a trace of remains on the surface?


texts: Do I need a checkride for an initial SIC A320 type rating?

texts:
I have an FAA A320 initial pilot-in-command (PIC) type rating but haven't flown the actual aircraft.

Currently I am undergoing the second-in-command (SIC) type rating. I have completed the ground school program, Fixed Base Simulator and the Full Flight Simulator exactly like the Practical Test Standards for PIC.

Do I now according to FAA need to do a check ride? Or should I be issued the SIC privileges?


texts: How can I use an ADS-B receiver to make my aircraft visible in Flightradar24?

texts:
I recently bought a SENTRY ADS-B receiver for the aircraft in order to track the flight.

How could I make Flightradar24 or Flightaware show my aircraft and how to register my aircraft on the website?


texts: What if all passengers pay to check in extra baggage?

texts:
Suppose a given flight is fully booked and everybody shows up. Not only have they all brought the allowed fully loaded carry-on & checked-in luggage weight but exceed the free-limits. They are all willing to pay extra for, say, an additional 10 Kg per person. Let's assume average weight for all passengers.

Will this cause the flight to go over the Maximum Take-Off Weight? If so, will the flight depart?
What are the measures taken for the passengers & their cargo for such flights? Are they divided to take separate flights?
What if everyone has 20 Kg extra? How about 30 Kg? Is there any limit to it?
Does it add if everyone is overweight?

I am asking this in a general context of a non-budget airline.


texts: Why were these crash location not located via ELT?

texts:
On Jan 14th 2019, at 9.10 Indonesia time, the CVR of the crashed Lion Air JT-610 has been found. Another vital device was found earlier.

There are three modern airplanes crashed in to water in Indonesia:

Adam Air, registration PK-KKW, Boeing 737-400, flight KI514, on 1-January-2007, crashed into Majene Sea due to the failure with the Internal Reference System (IRS), rested in 2,000m below the sea surface.
Air Asia, registration PK-AXC, Airbus A320-216, flight QZ8501, crashed on 28-December-2015, into Karimunjawa Sea, due to the failure with the rudder-travel-limiter.
Lion Air, registration PK-LQP, Boeing 737 Max-8, flight JT-610, crashed on 28-November-2018, into Java Sea. The crash cause is still under investigation.

Those three crash locations were found not by the electronic instrument system, but by fishermen.

Then my question is: why did the modern airplane has not been located via its ELT?


texts: What does "design-induced pilot error" means?

texts:
In the Slashdot article Is the Tesla Model S Pedal Placement A Safety Hazard? it says:

  what aviation analysts call a 'design-induced pilot error'

I tried to search for design-induced pilot error on Google, but found things too complex to understand! What does this mean?


texts: Can Part 141 instrument simulated time be logged?

texts: I'm doing my IR rating in Part 141, and the school says you cannot log simulated time in the logbook, whereas in Part 61 they are allowed. Why?


texts: How does CDI scaling transition from terminal to approach sensitivity?

texts:
I read in the AIM that WAAS vector modes will provide a linear course width of +/-1NM prior to the FAF and then provide a fixed width of +/-0.3NM to the point where an ILS splay would be 0.3NM and then tapers down to 700 ft total width at the runway threshold.

How smooth is the transition from the 1NM segment to the +/-0.3NM segment? Is it time-based, distance-based, or something else? Is it smooth at all, or is it actually an abrupt change?

Are all manufacturers following a common standard on how these scale transitions work?


texts: Why don't the US Navy Blue Angels fly Super Hornets?

texts:
The US Navy demonstration team has been flying the legacy Hornet for a long time and I was wondering why don't they use the Super Hornet? The legacy Hornet is over 30 years old and showing its age. I know there have been numerous incidents during shows where control surfaces have broken off the planes.

Why aren't they using the newer airframes? Is it the cost of upgrading? Performance concerns?


texts:
I have a question regarding this requirement as I work on my IFR SEL rating:

  Forty hours of actual or simulated instrument time in the areas of
  operation listed in paragraph (c) of this section, of which 15 hours
  must have been received from an authorized instructor who holds an
  instrument-airplane rating, and the instrument time includes [...]

The question is, if 15 hours of the 40 hours is required to be with an authorized instrument rated instructor, then how do you gain the other 25 hours of the required 40 hours?  Wouldn’t all 40 hours have to be with an instrument rated certified instructor?


texts: Why are some cardiac conditions disqualifying even if asymptomatic and corrected?

texts:
The FAA's website, in its list of medical conditions disqualifying for a would-be pilot, includes a number of cardiac conditions and procedures that would not intuitively seem, on their own, to warrant keeping someone on the ground, and, yet, automatically disqualify the applicant (even if they are completely asymptomatic or the condition has been corrected) from receiving a standard-issue medical certificate, requiring them to beg the FAA for a special-issuance certificate ([italicised brackets] indicate my additions):

[...]

Cardiac valve replacement [even if far in the past, with no history of symptoms or complications, and even if it completely and permanently corrected the precipitating condition]

Coronary heart disease that has been treated [even if completely resolved by said treatment] ...

...

Heart replacement [even with no history of complications]

Myocardial infarction [even if far in the past and devoid of complications or any recurrence]

Permanent cardiac pacemaker [even if causing no complications and completely resolving the underlying pacemaker-necessitating condition]

[...]

Even if some of these conditions have the potential to be associated with other, potentially-impairing conditions (such as cardiac arrhythmiae, heart failure, or heart transplant rejection), those associated conditions, if present, would be perfectly visible in their own right, without the need for using the conditions in the aboveexcerpted list as proxies.  In addition, some of the above procedures (such as valve replacement, pacemaker implantation, and some types of coronary-artery-disease interventions) are curative, or functionally-curative, procedures, and, yet, automatically disqualify their recipients from receiving a standard-issue medical certificate.
Why is this?


texts: What is the backup for a glass cockpit, if a plane loses power to the displays/controls?

texts: I'm assuming there is still power to the rest of the plane - maybe it's an unrealistic scenario.


texts: What does "MERMA" mean on the Los Angeles TAC chart?

texts: Just wondering what "MERMA" means on the Los Angeles TAC chart:


texts: Where to relocate a bomb on a plane to minimize damage?

texts:
In a video blog I saw today on the net, an airline Captain said: "if a bomb is found on board in-flight, pilots are trained to relocate it someplace where it would do the least damage" without further details as to what place standard operating procedures suggest in this case.

Where should the pilot put the bomb to have the best chances of limiting the detonation damage and rescuing the plane ?


texts:
The Shanghai Maglev Train's max speed is 267 mph. Could a plane be made to follow a rail, surface area provided, if not an existing rail to travel along? How much faster could the heavily modified train/plane travel?
The plane is "on rail, not touching the track while following it, not over water but over a track made of concrete" or less.
Another way to ask, is how much would a very large cruise missile shaped vehicle benefit from using ground effect (possibly using curved surface area or rail to follow) verses not? Because the the rail is not directly supporting the wight of the vehicle, at least directly, how sturdy would that rail need to be? When done over water, the water is displaced by the air pressure under the ground effect plane.


texts: How does the A350 variable camber system decrease drag?

texts:
Just curious how the A350 reduces drag/fuel burn by extending the flaps ever so slightly during cruise. Everything I've read about extending flaps says that extending them pushes the centre of pressure rearwards. This causes a pitching down moment, which means you need to increase the AoA, but this affects drag and fuel burn negatively (a pitch up command increases the down force from the tailplane which has the result of increasing the effective weight of the plane, which requires an even higher AoA to compensate, which also increases the induced drag).

Here's how it works as per the (A350 Flight Deck and Systems Briefing for Pilots)

  Differential Flap Setting and Variable Camber

  The Differential Flap Setting and Variable Camber enable to optimize the loads and drag on the wings.
  Small flaps deflections (4° maximum) either symmetrically or asymmetrically, enable to automatically:

  Optimize the wing camber to reduce wing loads and drag
  Perform an optimized Lateral Trim function.


texts: Why would an airplane's nosewheel bounce during landing?

texts:
A pilot recently had an issue involving the nose wheel bouncing several times before settling down during landing.  Setup was as follows:

Cessna 162 Skycatcher
Simulated short field landing.
Full Flaps, per POH
Approach speed 50 KIAS per POH
Headwind 6 knots
Good condition, paved runway
Pilot has 30 hour in this specific airplane, ~100 landings in this specific airplane and has not experienced this before.

During the touchdown, the following happened:

Pilot flared at correct altitude.
Plane touched down, main gear first.  Main gear remained on runway.
Nose wheel then bounced 3-5 times before settling down on the runway.

Note: Bounce was not pronouced enough to cause a tail strike

This felt to the pilot like a PIO, but it was not a Porpoise as described in this post.

Questions:

Is this a PIO?
Why did the nosewheel bounce?
How can the pilot prevent this from happening in the future?
Should this occur again, how can the pilot minimizes the nose bounces?


texts: What is the origin for "squawk" having two different meanings in aviation?

texts:
In Aviation, a "Squawk code" is a common term for a "Transponder Code".
"Squawk 2345 and Ident"

But it is also commonly a way to report problems with an airplane.
"After I landed, I Squawk'd the broken ADF, and marked it INOP"

Do these two terms share a common history?  Is it purely coincidence that the same term is used for such different meanings?


texts: Is there any common research model for supersonic transport?

texts:
Is there any common research platform, like the Common Research Model of NASA for supersonic transport flight?

I assume that in aerospace industry, every company has his own research platforms depending on previous projects but was there any common model that companies shared for this purpose?


texts:
$V_{md}$ is the speed where the rate of sink is the lowest. So if you add full power, it should be the speed with greatest rate of climb, namely $V_y$.

But we also know $V_{md}<V_{bg}$ according to this speed polar graph as a general rule

If I connect the inequalities, I have $V_y=V_{md}<V_{bg}$. In the particular Cherokee I'm trained in, $V_y$ is 75 knots and $V_{bg}$ is 69 knots. So where in the reasoning am I wrong? Why isn't $V_y$ equal to $V_{md}$?


texts:
I saw a vortex generator mentioned in an aircraft listing.

What is a vortex generator?


texts: Are we on the "wrong boat" with eliptical spanload all these years?

texts:
In this video AL Bowers (former NASA chief scientis) talk how bell spanload solution  can reduce OVERALL DRAG by 60%(11% reduction in total aircraft drag due to spanload, elimination of the tail results in another 20-30% efficiency gain, and then 15.4% improvement in propulsive efficiency, the total efficiency increase is on the order of 60%) and  how today aeronauticals engineers dont understand at all "bell spanload concept".

So are we using "wrong" spanload solution(eliptical or all versions of eliptical) all these years?

sources :
NASA link

on bell spanload(right wing) resultant force is tilted forward, that cause thrust at wingtip. Eliptical spanload(left wing) has drag at wingtip.

often people think,that wingtip produce download(negative lift),this is not true, wingtip produce lift all the time you can see from graph lift dont go below zero line.


texts: Why is there a hole in one of the layer of an airplane's windows?

texts:
On a commercial airliner, there is a hole in one of the layer of the passenger windows.

See here:

and here:

Or in more detail:

Can you explain the physical reasons for this design choice?


texts: What is the meaning of the letters on the side(s) of WWII British aircraft?

texts: WWII British Spitfire and Hurricane had identification letters on the side of fuselage. Do they have a specific meaning? How are the letters chosen?


texts: Why don't aircraft use gimbaled engines instead of flaps?

texts:
Why do aircraft use flaps rather than vectoring the engine or angling the engine?

Elon Musk said he would gimbal the engine like a rocket with the aim of reducing total weight of the aircraft and thus increasing its range.

  Aircraft have all these unnecessary things like tails and rudders and elevators - not needed. Just gimbal.. anyway.. gimbal the electric fan. For some weird reason gimbaling motors is normal in rockets and not in aircraft. Why not.— Elon Musk (YouTube)


texts: What's the technique for landing without one set of wheels?

texts:
A Boeing 747-400 recently made an emergency landing without the wheels under the right wing:

News story
Photo of the undercarriage
Video of the landing from the end of the runway

What's the standard technique for carrying out such a landing?

What might go wrong? Does it require more runway? Is there a significant risk of dragging one wing on the ground?


texts: Will it be more efficient if airplanes flap like birds?

texts: Many airplanes have parts that are designed to mimic some features of animals. I have also read that birds are incredibly more efficient than most of the airplanes we see today. I wonder, will the future passenger airplanes resemble a big flapping bird? Considering that in the future we might have a lighter and more durable materials for wings.


texts: Fabric-covered Clark Y Max Coefficient of Lift

texts:
I'm looking at the Aeronca C-3 Collegian, which had a Clark Y airfoil, and I'm finding the following:

Wing area: 142 ft²
Empty weight: 466 lbs
Payload: 470 lbs
Stall speed: 38 mph

When I do the math for that wing area, a gross weight of 936 lbs, and a stall speed of 38 mph, I get a coefficient of lift of of about 1.8; that's higher than I see from either simulations or wind tunnel tests.

I'm inclined to trust these figures, since they line up with pilot reports on the C-3, and the airspeed range would be very narrow if the stall speed were higher; could it be that distortion of the fabric results in a later stall?  The little I could find on the subject doesn't suggest any such effect.  What's going on here?


texts: What is the correct answer to this Mass and Balance calculation?

texts:
I was practising some mass and balance questions and I found that my answer is a little bit too far from the listed answers. Can anyone help me to see if I did something wrong?

The question was:

  Given that the Dry Operating Mass (DOM) is 27 372 kg, there are 12 000 kg of
  trip fuel and 4 000 kg of fuel are expected on landing, what is the
  maximum allowable traffic load for the Medium-Range Jet Transport
  (MRJT) aeroplane?

  23,923
  23,528
  19,005
  19,428

My solution was:

  Operating mass = DOM + Usable fuel

  $27 372 - (12 000 - 4 000) = 19 372 kg$

That doesn't match any of the options, so what is the correct answer?


texts:
Why is it that black boxes don't float?

From what I gather the answer is:

  So they will not float away from a water crash site. The ping can be heard underwater with sonar. Finding the ping, finds the site.

But why not have two black boxes one that floats and one that stays with the aircraft?

That way if a plane is lost at sea, if we find the black box floating, we could use the data to find the other black box and the crash site. Plus the benefits of having a redundancy are enormous.


texts: Why landing gears still need bungee springs?

texts:
While studying landing gear, I came across this term 'bungee spring' to which there was no definitive explanation in text with regards to its usage.

So in the image, you can see for the jury strut/ drag brace down lock strut there are 2 bungee springs used even after the presence of downlock actuators.
As per my assumptions they must be used to give the jury strut some extra kick while extension and gravity extension and improve redundancy or there's some other reason?


texts: What is the fuel consumption of an aircraft in a holding pattern?

texts:
I am doing a research about fuel cost when an aircraft is about to land. they may be asked to be hold due to the traffic congestion at the runway. consequently they consume extra fuel. My question is how I can estimate the cost per minute or second being late of their *target time. Where can I get more details on this?

*target time: As I noticed each aircraft has a target time to land which is the most economical time and speed for them.

My research is about aircraft landing scheduling during rush hours where there are several objective functions such as maximizing the runway utilization, minimizing total delay and fuel consumption to be considered. these objective functions are subject to some constraints like aircraft's time window (earliest landing time,latest possible landing time), minimum time separation, Constraint position shifting...
In the literature that I have read so far they considered a fix fuel cost as a function of delay. as an instance: "Vj denotes the cost per unit time of the extra fuel associated with lateness relative to ULTj , then the overall extra fuel cost is : summation of Vj * (Landing times - ULTj) " (Aircraft Runway optimization, Mesgarpour, 2012)
Since it is more mathematically issue no body really pay attention to the details of that fuel cost or any other cost caused by the delay.


texts: Do stratospheric business and military jets use the North Atlantic Tracks?

texts:
The North Atlantic Tracks (NATs) are the airways generally used by airliners taking approximate great-circle routes between North America and Europe; due to the wild swings in wind strength and direction over the North Atlantic from day to day and place to place, the NATs are not fixed in position, but, rather, are plotted fresh every morning to allow transatlantic flights as much tailwind (and, thereby, as much groundspeed and as much per-flight fuel efficiency) as possible, and, then, sent to all the airlines preparing aircraft for transatlantic runs.

In contrast, the weather in the stratosphere - the layer of air lying above the tropopause (the upper boundary of the weather-prone troposphere; usually lying between 35 and 50 kilofeet at temperate and polar latitudes, but generally located at a much higher altitude over the tropics) and below the stratopause (the upper boundary of the stratosphere, and the lower boundary of the poorly-known mesosphere; usually located at around 165-180 kft) - is essentially uniform constant from day to day, changing (usually) only slowly, with the seasons.  This removes the raison d’etre for the moving NATs, as no particular stratospheric route is objectively significantly better than any other of comparable length.  For this reason, the Concorde (cruising at flight levels [FLs] 470-600, equating to an altitude of 47-60 kft, give or take a kilofoot or so)1 did not use the NATs, instead following, for open-ocean stratospheric cruise, one of a set of preplotted fixed airways, the locations of which did not change from day to day.

But the Concorde, even when it was still in service, wasn’t the only aircraft to cross the North Atlantic in the stratosphere; business jets (at least the many that are actually capable of doing so) routinely cruise at between FL 450 and FL 550 or so (the exact upper limit depending on the model of bizjet), and some smaller military jets routinely cruise above FL 600 in order to minimise aerodynamic drag on long-distance flights.  These other high-altitude jets would stand to benefit just as much as the Concorde did from being able to use fixed stratospheric airways rather than having to follow the variable and non-stratospheric-aircraft-benefitting NATs; yet, I’ve only ever come across mention of immobile stratospheric routes with reference to the Concorde, and in language that makes it sound like the Concorde was unique in its use of these routes.

So do stratospheric bizjets and military jets have to use the NATs (and, if so, why?), or do they get to use fixed stratospheric routes, like the Concorde did?

1: An aircraft’s flight level is the altitude, in hectofeet, that its barometric altimeter (if properly calibrated, and assuming the aircraft’s pitot-static system is working properly) indicates when set to standard pressure (29.93 inHg).


texts: Transonic Airfoil with high critical mach number

texts:
does anyone know, how I can find a transonic airfoil (high subsonic, Ma=0.88) with a high critical mach number?

I know that if I know c,0,min = minimal pressure coefficient of the airfoil, then I can calculate the critical mach number.

But when I use Xfoil for plotting the pressure distribution, I only get a nice picture, but I can not write out the data for the pressure distribution. otherwise I could determine the critical mach number.

Maybe someone has some hints for me?

Thank you

Lucas


texts: Why are aircraft parts built in different places and assembled in one?

texts:
Airbus has its manufacturing facilities in Spain, France, Great Britain and Germany. Each country produces different parts of the aircraft and is finally assembled in one place.

Why is this? Wouldn't it be more economically sound that everything was built and assembled in one place? Is it because all of the countries in Airbus group have to have some work? Is it because you can't get all those workers in just one country? I don't understand economical and logistical logic behind it (if there is one).

I believe Boeing has the same practice which puzzles me even more, since USA is more of a one country than EU. Is it really cheaper to manufacture something big as a wing overseas and transport it to one facility?


texts: What are the costs involved with getting a 2 seat ultralight?

texts:
About 7 years ago I got my private pilots cert but I let my medical cert lapse.

Now that life is more settled I'd like to get back into flying but I want something that I can keep at home. I was thinking of a two seat ultralight with folding wings.

My questions are:

What do I need to do to get back into the flight seat
What are some good options for a 2 seat folding wing ultralight that has a few hour range
What are some hidden costs of owning a new or used ultralight


texts: Can the need for an engine overhaul affect the ETOPS rating?

texts:
I read this news:

http://edition.cnn.com/2016/04/23/us/boeing-dreamliner-engine-fix/index.html

So seemingly the reliability of the 787 engines made by General Electric is not as high as expected and need to be overhauled to increase reliability. If one engine fails due to icing there should be also increased chances that the second one may fail as well.
Does it mean that - even temporarily - this may have an effect on the plane's ETOPS rating?


texts: What provides the greatest thrust in a high-bypass turbofan engine?

texts:
I'll try to make as much sense as I can with this question.

I've been flying quite often in 2015, and I have recently wondered this question regarding high-bypass turbofan engines. I know that there are two primary parts to the high-bypass turbofan: the fans themselves that pull air from the front of the aircraft through the engine, and the fraction of that air that gets compressed and undergoes combustion inside the combustion chamber.

Given those two main parts that I know about (or so I think I know about), which provides the greatest amount of thrust for the aircraft, the suction and escape of non-combusted air out of the back, or the hot combusted air that is ejected out of the back of the engine?

Thanks for reading, and I hope this question makes sense.


texts: Would a refueling stop be cheaper than finding lodging for all the passengers?

texts:
This is somewhat late followup question to my original question. Basic story was flight got delayed by almost 24 hours because first, technical reasons, secondly temperatures were very high.

As far as I can see airlines had to accommodate all the passengers somehow, either in terms of hotel rooms and meal or on other flights. There are costs involved in every action.

If they had taken off Abu Dhabi on less fuel and then refilled somewhere else would it have been cheaper? Would such refueling stop be allowed where passengers are not allowed to get off? Just fill her up and continue.

Without knowing any technical/legal/contractual details, my simplistic view is, you land at some airport around 6 hours away, fill up your tanks - might take around 1 hour and continue rest of your 14 hours flight. Your crew could be in time limits as they must be provisioning for full length of the flight plus possible diversions, moreover almost working as planned and you don't have to pay for hundreds of rooms and/or rebooking/re-routing costs of the passengers.


texts: How can an airplane fly with single propeller without rolling over?

texts:
I have no knowledge about aviation or mechanics or something. Recently I started a computer game 'besiege', a kind of sandbox-like game with bunch of parts to make all kinds of machinery.

And I'm trying to make a single-propeller airplane. What I'm concerned about is that it might roll over. I made a simple helicopter once before, which rotated to the other direction of the way propeller(of course facing up) did when only one prop is attached. I know this is why another small prop is at the tail.

So, is my airplane going to stay in balance with single propeller? I considered putting one on another rotating to the opposite direction in the same speed too, but that isn't the way I am planning to. Thanks in advance.


texts: When builders say they load tested a wing, most of the time what they are saying is that they load tested the wing spar(s) by turning the plane upside down and putting weights on the wing. This procedure doesn't load test the ribs, so how do you load test a single rib?


texts: Who is this flyer seen in Oakland c. 1929?

texts:
Looking for identification of the man on the left. Second from left is W.A. "Sandy" Sanders, third is Denny Wright, and fourth is Clyde Sunderland.

Oakland, around 1929.


texts: How will the altimeter read in air colder than ISA?

texts:
When flying in air which is colder than ISA (International Standard Altitude), how will the altimeter read compared to true altitude?

My manual says the altimeter will over read - why?


texts: Identify canard, low-wing, single pusher-prop plane over Upstate NY

texts:
Yesterday, August 11, at around 3:30 pm, I saw an unusual-looking plane flying over Ithaca, NY. It seemed fairly small -- approximately business jet sized. Unfortunately, I didn't have time to get a picture, but I remember several distinctive aspects of its appearance:

Canard and seemingly no conventional tailplane
Single pusher propellor
Low, swept wing with winglets. Pretty sure it was tapered.

I only saw the plane from below, so I don't know anything about design aspects on the top side of the plane. I checked on FlightAware and FlightRadar24, and didn't see any obviously-matching flights, but I may have missed something. Based on some googling, what I saw seems pretty close in appearance to the AASI Jetcruzer (picture below), but apparently only five of these were ever registered, all in California. According to that same page, only one remains registered, most recently in Washington. The most recent flight recorded with its tail number (N200JC) by FlightAware is from 2014.

AASI Jetcruzer

Additionally, the wing profile doesn't look quite right to me. Another somewhat similar-looking plane that has a more correct-looking wing is the Beechcraft Starship (picture below). However, I'm quite sure that what I saw only had a single propellor. According to the same website, only one specimen of this aircraft remains registered, and similarly its last flight recorded by FlightAware was in 2011.

Beechcraft Starship

Are there any more likely possibilities for the aircraft I saw than one of these rare and seemingly seldom-flown planes?


texts: Why was I getting an uncomfortable feeling in an R22 at 3,000 feet?

texts:
I was thinking through my flying experiences when I remembered a strange sensation while I was a student.

In a Robinson R22, with about 35 hours experience, I was doing a solo flyout to a nearby airfield for a cup of coffee and a look at the weekend traffic.  To get there, I had to cross a MATZ which included some permanent danger areas up to 2,500 feet.  I'd transited this MATZ several times with a call to the tower but on this particular occasion, I couldn't reach anyone.

Being quite inexperienced, I didn't know if it was just unmanned, I had the wrong frequency or something else so I decided, with no particular place to go, to climb to 3,000 feet and go over the top.  One lesson learned is how long it takes to get to 3,000 feet in a Robbo, especially in a climbing spiral :)

Anyone who has been in an R22 will know that the visibility is superb and as I climbed, the views were spectacular.

As I got to 3,000 feet and leveled off, I had this strange sensation.  It felt as if the aircraft was balanced on top of a tall pole and the cabin had shrunk to really small. I felt as if the aircraft might tip off the top of this pole and plunge.  I also found it difficult to believe the 70kts indicated since the apparent speed over the ground was so low which makes sense given that I'd only ever been that high as a passenger.

I really didn't feel comfortable although I wasn't scared, didn't have any anxiety and felt fully in control of myself but I did abandon the plan, got back down to the 1,000 feet I was more used to and completed a couple of circuits at my home field before landing.

What did I experience?  Has anyone else had anything like this?  I guess that it might be a symptom of vertigo but I have never had problems before or, perhaps something weird in my ear canals following the long spiral climb followed by a level out?


texts: Why does a hydraulic system failure increase the landing distance?

texts: Considering wide body aircraft, why do emergencies, related to hydraulic system failure, increase the landing distance?


texts: Can I get a sport pilot license while taking Mirapex?

texts: May I get a sport pilot license while taking the medication Mirapex for Restless Leg Syndrome?


texts: Why does climb gradient at Changi be at minimum of 6 and 7 percent?

texts: Changi airport, Singapore, runway 20C and 20R both point into the sea with no significant obstacle to clear. There is no residential area down there. Next land mass is about 15 km away (Batam, Indonesia) so I guess noise abatement is less of a concern. What could be the possible reason for specify climb gradient at 6 and 7 percent?


texts: Can someone help me explain what is the magnetic bearing, heading and track, please?


texts: How does single-sided deafness affect the different pilot licenses?

texts:
About 12 and a half years ago I lost the sense of hearing in my left ear due to borreliosis. However, I have always wanted to get a pilot's license at some point in my life. I am aware that for some (or even all?) licenses, a medical examination must be passed and one-sided hearing loss is essentially a no-go.

So my question is: What are my possibilities with my disability? What kind of license could I still be allowed to get or will I have to bury this dream?

I live in Germany.


texts: Can cabin pressure be lower than outside pressure?

texts:
In order to allow adaption to changed pressure, the pressure change in an aircraft cabin is stretched out over time. My observation is that the cabin pressure drops even before the plane takes off, and has not yet reached ground level at the time the aircraft lands. This would make sense, allowing for longer adaption times, but needs better sealing which is able to work both ways.

My question to the systems specialists: Can an aircraft cabin have a lower pressure than outside, and is the technique of stretching out the pressure change as explained above actually used?


texts: What could cause GE and Rolls-Royce turbofan engines to sound different?

texts:
I've often as a passenger noticed the difference of the sound coming from different airliners. I believe the two manufacturers I have compared are Rolls-Royce and GE, where the latter's engines sound more "electric" (funny enough) and the former's more distorted and noisy.
Do these observations make sense? And what could possibly create such a difference i sound? I was in the belief that engine design of turbofan engines is somewhat established and detailed.


texts:
I am looking to buy a Cessna 182.  I am trying to work out the sweet spot between age and price.  I am looking for a plane that will be really reliable.  I am looking to spend several months flying around the USA with my wife and prefer not to spend my whole time dealing with mechanics.  Some questions:

At what age does a regularly maintained airframe most commonly start needing frequent  repairs?
At what age does the depreciation slow down (so I can buy and sell the plane after three years with minimal loss)?


texts: Does the Fairchild Metroliner have any unusual handling characteristics?

texts:
I have been told by several people that the Fairchild Metroliner is a quite difficult to handle aircraft.
Aside from that, I have seen that it has suffered several accidents throughout its history.
Does it have any aerodynamic deficiencies in its design or something like that?


texts: Why do privater jets often fly at or above FL 400, but large commercial aircraft are usually in the range of FL 300 to FL 400?

texts:
With rare exceptions (like the Embraer business jet, which is simply their commercial jet with a different interior), almost all private jets fly in the more rarified air above FL 400.
But, if its more efficient, why don't airliner fly at the same sorts of altitudes on long flights?


texts: How to best recover from an excessive descent?

texts:
Suppose I found myself in a rapid, steep descent, perhaps right after breaking a spin. E.g. a 60 degree nose down with 100kt and accelerating rapidly, on a Cessna 172.

What might be an ideal recovery strategy, other than trying to guess/feel the optimal back pressure on the yoke? Obviously, if I pull back too hard I risk overloading the wings (to the point of collapse?) whereas if I pull back too gently I risk gaining too much speed, losing too much altitude, etc. Among other considerations, would it be advisable to enter a slip to (greatly?) increase the drag?


texts: Why do airline pilots have shoulder harnesses?

texts: On airliners, passenger seatbelts are simple lap belts. However, flight crews seem to have at least shoulder straps, and often five-point harnesses. Why do flight crew have more restraints?


texts: What is the typical pilot to aircraft ratio in military squadrons?

texts:
On aviation.SE, we already find this question addressing the pilot to aircraft ratio in airlines. It states that typical big airlines have roughly between 15 and 20 pilots per aircraft.

Military aircraft may require less pilots per aircraft:

airliners are in flight almost all day long every day
a typical airliner flight requires between 2 and 3 pilots (the 3rd one for very long steps or as an instructer)
a typical fighter is a one-seater
a fighter flight less time than an airliner
military cargo may flight more than fighters, but I hardly see a cargo used as much as a passenger aircraft (I may be mistaken)
HALE UAV may require several crew per flights but I don't know how long are those flight neither how many UAV can be operated simultaneously by one crew

When searching the number of each type of pilots (fighters, cargo/airliners, UAV) per air force (whatever the country), it is easy to come across recruiting websites (with requirement to become a military pilot and salary) but I fail to find anything about the number of pilot an air force has.

My question is : What is a typical ratio of pilots to aircraft in a typical military squadron? Does it differ between fighter squadron, transport squadron and UAV squadron?


texts: Is there a difference between MEA and MOCA within 22 nm of a VOR?

texts:
As we all know from our instrument training, the MOCA is:

  MINIMUM OBSTRUCTION CLEARANCE ALTITUDE (MOCA)- The lowest published altitude in effect between radio fixes on VOR airways, off-airway routes, or route segments which meets obstacle clearance requirements for the entire route segment and which assures acceptable navigational signal coverage only within 25 statute (22 nautical) miles of a VOR.

Whereas the MEA is:

  MINIMUM EN ROUTE IFR ALTITUDE (MEA)- The lowest published altitude between radio fixes which assures acceptable navigational signal coverage and meets obstacle clearance requirements between those fixes. The MEA prescribed for a Federal airway or segment thereof, area navigation low or high route, or other direct route applies to the entire width of the airway, segment, or route between the radio fixes defining the airway, segment, or route.

(Both quotes taken straight from the Pilot/Controller Glossary)

The only difference in language is the bit about 22 miles from a VOR.

Therefore, when you're within those 22 miles, there's no practical difference between a MEA and a MOCA, right?

If that's true, why is there an 1800 foot difference between the MEA and the MOCA within 22 miles of the PMM VOR on V84?


texts: How are airline pilots assigned routes? Are there easy and tough ones?

texts:
How are routes given to airline pilots? Is it based on the amount of flying experience they have or just random or based on availability?

Also, can routes be classified into tough and easy? If so, what are some examples? In not, then are all routes equal? Doesn't more traffic in a particular area correspond to a harder route?


texts: Are there other examples of human-electric hybrid aircraft?

texts: Has there been a human-electric hybrid aircraft after this. A more streamlined design; maybe capable of soaring as well...


texts: When should a pilot use the word "takeoff?"

texts:
I've been taught before that the word "takeoff" should only be used when reading back a clearance, and that when requesting a clearance pilots should advise "ready" or "ready for departure."

Here's the really critical point to the question. I've always believed that the word "takeoff" should only be used when reading back a clearance for such an action. Not when requesting a clearance for that action.

I've also heard it taught that this is true only for IFR flights but it's okay to ask for a clearance with the word "takeoff" when VFR. I don't see why the difference between VFR or IFR flight would be a factor here.

Has the ICAO, FAA or any other controlling organization released any written guidance on radio communications that covers this procedure?


texts: What are torque events and are they very common when flying a rotorcraft?

texts:
On rotorcraft like the MD500 the POH suggests that torque events be recorded in the aircraft maintenance logbook.

What are these events, are they common and how many are typically logged during the average flight?


texts: Can you obtain a pilot license with impaired vision / being blind in one eye?

texts: A friend of mine is blind in one eye and has normal vision in the other eye.  Would this prevent him from getting a Private Pilots License in the US?


texts: What is the difference between a go-around and a missed approach? What are the steps involved in each of the procedures?


texts:
Does skin friction change with AoA or stay constant during change in angle of attack?
I think that local airflow velocity change with AoA so this must affect skin friction ..
But what definiton tells?


texts: Can a helicopter like the R44 be lifted up by his rotor head?

texts:
I am curious if a rotorcraft could be suspended from rotorhead for an extended period of time.

I am curious about R22 and R44.  I believe I have seen them in the shop lifted up from the 2 holes in the rotor head.

I am also curious if all helicopters have mount/lift points in the rotor head like an MD500C. Would you be able to do the same?

Or are you better lifting from the skids for a longer term lifting?


texts: Can you identify this jet turbine stage?

texts:
I was just wondering if anyone could give me any info about this turbine rotating stage I picked up at a yard sale today.

The stage measures 8-1/2" to the outside of the blades. The only markings I can find are TCYC5065 TT6776.0. It has 58 blades on the disk.


texts: What are the possible effects when an aircraft exceeds its approach speed limitations? i.e. unstable approach? Go around? Runway overrun I know a lot of factors come into play, however, I wish to determine the worst possible scenario


texts: What is the recommended pressure for refueling an Airbus A380?

texts: What is the recommended pressure on the hose that refuels an Airbus A380 when fueling this aircraft? How many litres per minute does it pump into the tanks. Can it safely be increased to reduce fueling time?


texts: There are some types of landings, can you, please, clarify them? Or even add some other types

texts:
I'd like to have explanations of these landing descriptors - what do they mean?

deep landing
bounced landing
hard landing
nose pointed down landing
technical landing
"smooth" landing
belly landing
landing gear up landing
partial landing gear up landing


texts: Is it legal to fly an aircraft with no navigation beacons, and only solid lighting?

texts:
Is it permissible for an aircraft to fly without red, green, and white strobe position lights?

Is it possible for any aircraft to legally fly with only a solid white or solid red light on the underbelly?


texts: Has anyone ever been penalised for buzzing a control tower?

texts:
Has there ever been a pilot who was caught and penalised for performing a "circus stunt fly-by" next to a control tower?

To clarify the question:

I mean legal actions took place; for example arrested, license revoked, attended a court martial (if the person is in military service)
the action must have been unapproved, possibly illegal. Pre-arranged fly-bys, such as air-shows, or the ones used to film Top Gun, do not count.


texts: Why is the A320neo considerably ahead of B737Max?

texts:
The A320neo has a 16% higher market share, 1022 more orders, 316 more MoU's and $122.1 bn greater estimated value than the B737Max.

Though both were released at almost the same time (231 days gap) with identical features and price (rather B737Max is  $15 mn cheaper), why is the A320 flying past the B737?

Data source : PDXLight


texts: What is angle of incidence of wing and tail at Savannah?

texts:
What is angle of incidence for wing and tail at Savannah?
Where can I find this data?
From picture it seems that  wing and tail has same angle.


texts:
The title says it all.

Can be clearly seen for example in this image:

(image source: Wikimedia)

The rest of the jet seems to have a camouflage.


texts: How long will an aircraft need to fly before it can land without dumping fuel?

texts:
Now, I know perfectly well that the literal and unhelpful answer to the question is long enough to burn sufficient fuel that it is no longer overweight for landing. What I'd like to understand is whether it is possible or not to give an answer about what's typical.

I am surprised that after flying all the way from Moscow to Ireland this aircraft had enough fuel on board to be still overweight (even given that it still had to go all the way to the Dominican Republic):

  An Azur Air Boeing 767-300, registration VP-BUX performing flight ZF-973 from Moscow Vnukovo (Russia) to La Romana (Dominican Republic), was enroute at FL320 about 90nm south of Shannon (Ireland) when the crew decided to divert to Shannon reporting all their lavatories were blocked. The aircraft dumped fuel and landed safely on Shannon's runway 24 about 90 minutes later.

Typically, how much of an airliner's flight will be in an overweight-for-landing condition?

Does it vary so much between aircraft types, distances, passenger/cargo weights and other conditions that it's not simply possible to say what is typical, or is it possible to say that the case above is (for example) unusual?


texts: Anybody know the reason for the ‘Star Wars’ themed STARs into KATL?

texts: There are new RNAV STARs for arrival into Atlanta Class Bravo for KATL.  Does anybody know the reason a Star Wars theme was chosen for waypoint names eg TYFTR, WOKIE, NWHPE, etc?


texts: Can seaplanes land on normal airfields or in a marsh or muddy area?

texts:
I know there are some amphibious planes which can land on both water and land but how different is the their landing in comparison to that of a normal small aircraft?

Also, if seaplanes needs to go into some marsh, will that work for them?


texts: What are the pilot responsibilities for "maintain visual separation" clearances?

texts:
ATC will sometimes give pilots the instruction to maintain visual separation from nearby traffic.

I have a couple questions about this:

There is a related question here about traffic separation.
Is the required separation in this case different, and how can they judge this? (I would like a bit more detail for this specific case than was provided on the answer there)
Normally pilots will follow their flight plan and ATC instructions. What actions should pilots take to maintain separation? I mean, obviously whatever is necessary, but is there any standard method? Should they anticipate an issue and ask ATC if they need to change course?

This is mostly focused on IFR traffic, but how different would VFR be? The situation could be that ATC clears you for a certain maneuver, and other traffic interferes.

It is my understanding that for IFR traffic the controller would expect that there would be no conflict, but things don't always go as planned.


texts: Why aren't planes loaded from both ends?

texts: Related to this question about plane loading efficiency, if planes have multiple entrances (generally 6 or more) why are planes not loaded from both ends? I think I've seen it happen sometimes, but the majority of my flights are on 737s and are just loaded from the front entrance.


texts:
sorry for the terrible quality, it's what I've got. I've not been able to find anything looking like it using google image search. It looks too detailed for a random bit of clip art.
Possibly around 12-15 feet long by 2-3 feet diameter


texts: What is the role of discontinuous surfaces on the inside and outside elevons of the F-117?

texts: Why are there discontinuous surfaces on the inside and outside elevons of the stealth F-117? Will that not be highly reflective to the radar?


texts: What are the best places to gain the most altitude in a glider?

texts: I'm a beginner pilot and I started with gliding. How to spot the best thermals and what is the most efficient way to climb?


texts: Do gyroscopic forces (from rotating engines) significantly affect yaw or pitch?

texts:
It occurs to me that jet engines are very heavy objects operating at high RPMs. This must have a very high angular moment and thus a high gyroscopic force.

This would restrict rotation when trying to yaw or pitch. Rolling, however, would not be effected.

How big of a problem is this? I imagine it is a concern to military aircraft as they want to be as maneuverable as possible. But I'm very interested in commericial efficiency too. I wonder if the giant A380, for example, had to be given greater elevator and rudder authority to help it pitch up at takeoff.

Note: all engines rotate but I'm assuming the jet engine will have by far the highest angular moment due to the weight of their turbines and compressors. Turbofans with high bypass ratio probably have the greatest gyro forces due to their huge fan in addition to heavy spinning spools.

(Presumably, contra-rotating engines would have zero gyroscopic forces.)


texts: SR-72 --- is the speed reported in this story wrong?

texts:
I was just reading this story from Sky news and reported the following

  Lockheed Martin says it is close to developing a military plane that flies at Mach 6 - six times the speed of sound, which travels at around 762mph (1,236km per hour).

Am I missing something, or is that a misprint?

6 * speed of sound at sea level = 4567.2423 miles per hour


texts: Why can't there be more than 4 anti-shock bodies on each wing?

texts: Most airliners have 3 or 4 shock bodies to reduce wave drag. But why can't there be more anti-shock bodies per wing?


texts: What happens during Engine Performance Restoration

texts:
What is the typical process during an Engine Performance Restoration?

I am trying to find a resource that gives an overview of what happens but I have not been successful.

Any help would be much appreciated.


texts: Is a fighter pilot allowed to fly two different model fighters?

texts: Does a fighter pilot who flies the F/A-18E have permission to fly the F/A-18F for training a new pilot? Or does an F/A-18E pilot fly with an F/A-18F for night bombardment?


texts: What is the current regulatory progress regarding autonomous aircraft carrying passengers?

texts: Are there any lobbying groups working towards this? Has there been any word whatsoever from the FAA on this topic yet?