texts: Is a biplane without dihedral more stable than a low wing monoplane without dihedral?

texts:
I was wondering if a biplane's top mounted wing created the same stability effect as that of a high wing airplane?
Also, would the unstable effects of the low wing cancel the stability provided by the high wing and condition the biplane to behave like a mid wing airplane? If yes, is it one of the reasons why manufacturers make the top wing longer or is it just extra length provided to generate more lift and replace that lost due to wing interference?
This questions have been bugging me for some time now.
Someone pls clarify me.
Maybe I missed something...


texts: What's a stepdown fix in a non-precision approach procedure?

texts: Could someone explain to me what's a stepdown fix in non-precision approaches?


texts: Do modern aircrafts like 747/787/A320/A380 have some Plug and Play subsystems/sensors?

texts: Do modern passenger aircafts like 747/787/A320/A380 have some sub-system or sensors which are plug and play that might include some kind of sensors or radars which comes as optional and can be used plug-play as and when needed as per the requirement?


texts: How can I legally land VFR in class D airspace with low and few clouds?

texts:
This question is a bit specific because it applies to an actual situation I'm observing for a flight I'm looking to make tomorrow.

I'm a Non-IFR rated pilot looking to fly class D airspace. My destination airport is anticipated to have clouds (FEW @ 1,000 ft). In this case, it seems like it would be pretty easy for 1 single cloud's position to make it impossible for me to land at the airport despite being able to (likely) safely land. For example, if the cloud were over the middle of the runway, but I had plenty of runway at my landing end, it's technically possible that the requirements for distance from clouds could keep me from landing here.

I realize the example is trite, but hopefully this illustrates my point.

What is the appropriate way to handle this situation as a pilot?
I'm calling up tower before I have a visual on the airport (which would be the case in this situation) would they likely deny clearance to land due to knowing that a singular cloud sits out there and would cause a bust the visual flight rules or might they clear me without regard to the rules?
What is considered cloud clearance in this situation? I realize clearance is easy to determine if you are directly above, below or adjacent to a cloud, but more commonly you'll be at some sort of angle to the cloud as in the picture. Shown are two ways to consider cloud clearance (in red and blue lines)


texts: Does joystick position control bank angle in some Airbus aircraft? And what happens when the pilot deflects the joystick when wheels are on ground?

texts:
Does joystick position control bank angle rather than directly controlling aileron/spoileron deflection in some Airbus aircraft?

Also, what happens when the pilot deflects the joystick when the all wheels are on the ground and the bank angle (or roll rate) cannot change substantially?

Also, if the pilot is landing and the left main undercarriage assemblies are not extended for some reason, when the wheels on the right main undercarriage assemblies touch the ground, will maintaining a strong right control input on the joystick help delay the left wingtip (or engine nacelle) from contacting the runway, or not?


texts: Are there certification requirements on Dual Inputs?

texts:
Is anyone of you aware of (certification) requirements or similar for dual input, and the priority management of dual controls?

I only know the Airbus philosophy of summing both inputs and limit them afterwards, but I wonder if there are any requirements on this?


texts: I am over 6' 2" and endured an extremely unpleasant 9-hour flight last year.  Shorter folk were just fine. Are there any guidelines or regulations for seat legroom on airlines?


texts: I have tried to find what timed approach is, but I cannot find any reference to it. Could you let me know what it is and when it is used?


texts: Is it safe to fly a glider when I can't move the stick fully left and right?

texts:
This past Saturday, I started training in a Schweizer 2-33A glider.

When I got in the glider for the first time, I found that I couldn't move the control stick fully left and right, because my legs were in the way. I could only move it about halfway. I could move it fully forwards and backwards, though.

Is it safe to fly a glider like this? I asked my instructor about this, and he said it was fine.

Normally, you're not going to use full aileron deflection anyway, unless the glider is on the ground and moving slowly.

On the other hand, if you get into an unusual attitude somehow, then the limited aileron travel could increase the amount of time it takes to recover. But I don't know if that's a realistic concern.


texts: How do I determine the VFR pattern altitude at an airport? Can I find it on a sectional?


texts: A pilot has filed an IFR flight plan.  While airborne, he feels like changing to VFR flight. Can he request for it and what are the conditions?


texts: Is there any size of tethered kite that is regulated by the FAA?

texts:
Civilians fly kites for entertainment.

Is there a limit, after which the kite is considered an aircraft and becomes regulated?

Is a kite considered a balloon, after a certain size?  Do technology or other control apparatus make the distinction?  Is it purely height-based, and size is (mostly?) irrelevant?


texts: Why did the turbojet replace the piston engine?

texts:
Many people say that this was because aircraft powered by turbojet engines were faster during WWII. However the Grumman F7F-4N Tigercat, a fighter powered by a piston engine, flew at a maximum speed of 460mph and the Gloster E28/39 (first British jet engine aircraft) flew at a maximum speed of 466mph, which is not that great a difference.

Others say it's because aircraft powered by piston engines cannot fly as high as jet engine aircraft, but what is the reason for this?

Why did jet engine aircraft replace piston engine aircraft?


texts: Is any convention to tell the propeller rotation direction of an airplane?

texts:
Here are two airplane with single and dual engine.

From single engine airplane we know there is TURN LEFT tendencies. There are four tendencies (Torque reaction, Precession, Slip Stream, and P-Factor) caused by the propeller rotation, which it rotate clockwise seen from the tail to the nose side. If the rotation is opposite, probably the name will be TURN RIGHT tendencies.

Then my question, is any convention to tell the propeller rotation, such as, rotation is must be seen from tail or pilot side. I.e:

Clockwise, mean the propeller is rotates clockwise seen from the tail nose side. Vice versa:
Anti/contra/counter clockwise, mean the propeller is rotate anti clock wise seen from nose to the tail side.

The four tendencies are like confirming that the rotation is clockwise seen from tail side to the nose side. But however, I need a valid info regarding this, which expected the convention is applicable to another airplane with multiple engines/propellers and it will confirm that no need to tell where our stand point when saying the propeller direction. It is enough to say, clockwise or anti/counter/contra clock wise.


texts: Could a moving film of gas reduce aerodynamic drag?

texts:
Source: Wikipedia
In this image there is depicted a system which creates, using the Coandă effect, a film of gas traveling along the surface of a body. If this object was moving through air in the "up" direction on the image, could aerodynamic drag be reduced since the gas at the boundary layer of the body would have lower velocity than the free stream air (in relation to the body)?


texts: What is CAS and EAS and how to calculate from IAS?

texts:
I am trying to understand IAS, CAS, EAS, and TAS. I was under the impression that CAS is IAS corrected for instrumentation error and position error. The error is specific to the type of aircraft. Why then on the wikipedia page for CAS is there a formula to calculate CAS which is a function of just dynamic pressure? Where did this formula come from and how can it be valid if the correction for CAS is aircraft specific?

Also, EAS is CAS corrected for compressibility. What does this really mean? How can I convert a speed in CAS to EAS?


texts: Why does the LEAP 1A HPT run at such a high RPM?

texts: I've watched the N2 on the LEAP sit at 100% at cruise and fluctuate as high as 101%.  Why does the HPT run at such a high RPM?


texts: How will the Rolls Royce UltraFan provide reverse thrust?

texts:
When perusing the Wikipedia article on the upcoming Rolls Royce UltraFan engine, I noticed that it cited an interesting bit of information from an Aviation Week article:

  As the fan system is designed to vary pitch in all phases of flight, including landing, the nacelle will not include a thrust reverser.

I understand that a turboprop can enter the beta range in order to vary the blade pitch into the negative range in order to supply reverse thrust.

However, my understanding of the UltraFan was that it is to be a geared turbofan design with the fan and the core ducted inside a more-or-less conventional turbofan nacelle (minus the thrust reverser, apparently.)

My question, then, is how does the airflow work through this engine with negative fan blade pitch?

When the blade pitch goes negative, then the fan will be blowing air out the intake rather than sucking it in through the intake, no? Where then is the air coming from which is getting pushed out the front and where is the air coming from that is still needing to go in the normal flow direction through the core? Does the flow direction through the bypass ducts reverse?


texts: Does the FAA maintain pilot records from before 1998?

texts:
I have held a PPL with an instrument rating since 1999, and I am desperate to continue, but I lost my logbook.

Is there any way to get records from the FAA about my total flying time?

I contacted my flight school, but they say they don't have a record of me, so they asked me to start over from 0 hours.

What can I do?


texts: What are the financial implications for Lufthansa (and other airlines) of keeping the back row of their A320neo free of passengers?

texts: After the recent EASA airworthiness directive concerning the potential for weight and balance problems with the A320neo, Lufthansa announced it would no longer sell seats on the back row of those aircraft.  What are the financial implications for airlines of not being able to fill an aircraft?


texts: How to relay an emergency to ATC while on the ground?

texts: So we have somebody that contacted ATC via a Facebook post. Suppose I saw that Facebook post and believed it to be a genuine emergency. How can I contact ATC?


texts: Is it possible to reach an A340's fuselage from the ground?

texts:
There is this ATC recording where an A340 pilot requests to leave the aircraft and close the fuel panel on the bottom of the fuselage, while the aircraft is on a taxiway (the request is made at 2:50). Now, here is a picture to show how to get in and out of an A340 without deploying the emergency slides and causing even more issues:

(Source: http://www.flugzeugbilder.de/show.php?id=695499 and yes, I realize this is technically a A330)

However, the picture also makes it look like it not actually possible for anyone to reach the fuselage from the ground. Is that actually the case? And if so, how would the pilot actually reach the fuselage and close the fuel panel?


texts: How do you know ELT's batteries used more than 50% of their capacity?

texts:
Batteries in ELT need to be replaced or recharged when the transmitter has been used for more than 1 cumulative hour or when 50% of their useful life.

How could I know it's already 50% or more than 1 cumulative hour?


texts: What’s service does ATC service include?

texts:
As I’ve studied on ATC service and airspace class by referring to ICAO Annex, I have some doubts on ATC service.

According to ICAO Annex 11, Class D airspace is defined as “IFR and VFR flights are permitted and all flights are provided with air traffic control service, IFR flights are separated from other IFR flights and receive traffic information in respect of VFR flights, VFR flights receive traffic information in respect of all other flights.”

When referring to other definition such as ATS service, It is divided into ATC service, flight information service and alerting service. And I think separation and traffic information service are included to ATC service of ATS service.

So, when I read the definition of Class D airspace that IFR and VFR aircraft are provided with ATC service, I think separation and traffic information service are also provided because these are the ATC service. However, as you guys know, although ATC service is provided to all VFR and IFR in controlled airspace, separation and traffic information are selectively applied depending on airspace class.

To sum up, I want to know what ATC service includes and whether traffic information and separation are one of ATC service or not.


texts: Was the Space Shuttle landing sequence executed manually or automatically?

texts:
I was motivated by another SE Aviation Question where the complex set of manouveres needed to land the space shuttle is described to ask the following question:

Is the landing handled manually or is there an auto landing system? I suppose there is a high fidelity simulator to train all this on?

I wonder if that simulation engine has gotten into any of the enthusiast flight simulator software?

How does the space shuttle slow down on the re-entry, descent, and landing?


texts: Why is a Lockheed MC-130J Commando II creating such a loud droning sound?

texts: Today I heard a loud droning sound which is really unusual in the area of west London I live in; so I went on ADS-B exchange and it showed a USAF Lockheed MC-130J Commando II flying literally right over my house. However, it showed the altitude as being 27,000ft! I didn't know you could hear airplanes which are flying that high. Is it a case of the engines being so loud on that particular case or maybe the wind transferring the noise etc?


texts: What are the factors required to estimate the minimum required power for an experimental aircraft of a specific mass?

texts:
I have already viewed these questions:

Basic aircraft performance: how can you calculate the required power?
How can I estimate the required T/O power for propeller aircraft?

But is there a comprehensive list of factors, and a single formula for estimating the minimum required power, including the take-off power, for an aircraft of a certain mass?

EDIT: I'd like to be a bit more specific - I'm looking to estimate the minimum required power for an experimental micro-light (not ultra-light), for which I have a 3D model, and estimated MTOW in kg. The primary objective is to fly at a 'safe' speed (above stall speed - probably around 80 - 100 knots). So I have the following with me:

3D Model of Airframe: Composite + Foam (Burt Rutan style), closely resembles a Cirrus SR22
MTOW estimate: approx. 340 kg
Speed range: 60 - 100 knots

Can I calculate the minimum required engine power from these factors? Do I need more? How do I calculate the minimum required power (or is it thrust)?


texts: How can a pilot involved in serious accident remain unknown?

texts:
Somewhat similar to this question. A short part from Wikipedia article about Emirates Flight 521 (emphasis mine):

The captain was an unnamed 34-year-old UAE national who had been with Emirates since March 2001 and had logged 7,457 flight hours, including 5,123 hours on the Boeing 777.

In which situations or under which circumstances a name of pilot involved in serious crash may remain unknown or hidden?


texts: Do modern aircraft require rudder input in order to perform a coordinated turn?

texts:
With today's state-of-the-art electronic systems in modern aircraft, do aircraft equipped with autopilot systems, still require pilot rudder input to keep a turn coordinated?

For the context, I'm assuming the pilot is hand-flying the aircraft so the autopilot must be at least partially disengaged to let the pilot manually initiate and perform the turn via the yoke/stick, but still make the rudder use unnecessary or optional.

For example, would an F-16 pilot still need to apply the rudder during a turn? If the military case is not generic enough, how about an airliner pilot? Or a GA aircraft like the Cirrus SR22?


texts: How to simulate magnetometer used on navigation system?

texts:
Magnetometer is used to measure yaw angle which will be used on AHRS system.When I simulate the magnetometer in matlab, I feel confused about what unit should be used for measurements magnetometer?Should I use μT(microtesla),rad or degree?
I know in real world, the magnetometer is to measure earth magnetic field, so it should be μT. the reason that I feel confused is that:In some papers, their simulation says $B_{i}$(earth's magnetic field) is given by $[\frac{1}{\sqrt{2}},0,\frac{1}{\sqrt{2}}]$ or $[1;0;1]$,symmetry-preserving observer.page11 and they didn't give the unit of above vector. I also find a book, called Small Unmanned Aircraft: Theory and Practice, it introduced how to simulate IMU sensors and says the standard deviation and bias error of Magnetometer could be 0.3 degrees and 1 degree.
So I am totally confused about the unit and value of the earth's magnetic field or Magnetometer measurements.


texts: What is the technical name of the electric window dimming system?

texts:
I have recently flown from Mexico City (MMMX) to Tokyo, Japan (RJAA) in a Boeing 787 of All Nipon Airways (ANA).

The plane had an electric system for dimming the windows.

Does the window-dimming system have a technical name?


texts: Why do airlines require passengers to return to their allocated seats for landing?

texts:
Airlines which allocate seats often make announcements prior to landing to request passengers return to their allocated seats. What is the motivation for this requirement, especially since I have never seen the requirement rigorously enforced by the crew (by requesting sight of the boarding pass).

The requirement is not simply a polite way of requesting standing passengers return to their seats – for two reasons:

Crews are typically explicit in their language when giving directions, such as requiring standing passengers be seated. It is clear from the phraseology and emphasis given in the announcements that returning to the allocated seat is a critical component of the request.
On a recent long-haul flight, a couple seated in my row were offered to relocate to vacant seats in an exit row for the duration of the flight, provided they returned to the allocated seats for landing. (They were not, at the time, standing.) Furthermore, in the event, only one member of the couple returned; the other remained in the non-allocated seats (an example of non-enforcement).

Some possible motivating factors I have considered:

Weight distribution – ensuring the flight envelope of the aircraft is not exceeded during critical phases of flight. However, I have encountered this situation on wide-body jets on long-haul flights (e.g. A346, A388), where a handful of passengers, of nominal mass, being situated elsewhere in the plane does not seem cause for concern.
Collection of personal effects – if passengers relocate after takeoff, they may leave personal belongings at their original seat, unwittingly or not.   A requirement to return to the original seat may:

trigger passengers to locate & take with them items left/forgotten at their original seat, reducing the cost of the airline returning these to passengers later.
improve the efficiency of disembarking by avoiding passengers who need to move against the flow to collect belongings elsewhere in the aircraft.

However, I have encountered this after long-haul flights with tens of hours of turnaround time on the ground, so eliminating a few minutes from the disembarking time of some passengers does not seem a high priority (and, in any event, the effect of reducing the overall exit time would be in the noise and difficult to quantify).

Limitation of privilege (hence, revenue protection) – passengers in a higher cabin tier may benefit from certain privileges upon landing, such as the possibility to disembark the aircraft more quickly. However, crew are normally hot on ensuring passengers do not self-upgrade to a higher cabin, so this would not seem to apply.
Emergency preparedness – for example, ensuring there is a sufficient cabin crew to passenger ratio in all areas of the aircraft to meet emergency / evacuation requirements. Such ratios may be upset in the event passengers relocate far from their original seat. (If so, why is this not an issue when in the cruise?)
Passenger identification – air crash investigators often use seating manifests to identify remains of deceased passengers, so this requirement could be to ease any future investigation in the event of an incident on landing. (Similarly, what about the rare likelihood of an emergency which rapidly develops while in the cruise, without opportunity for passengers to relocate?)

None of these reasons seem to entirely justify the requirement for this routine request or its existence across all manner of aircraft types.

My questions

What benefit do airlines or the wider industry gain from this requirement?
Why is it not rigorously enforced by crews?
How do airlines which do not allocate seats to passengers satisfy the same requirement when there is no published seating manifest in advance of passengers entering the aircraft, or why are they exempt from such requirements?


texts: Is there any cockpit procedure used to avoid shutting the good engine, instead of the bad one (on fire, for example)?

texts: Reading some reports, about the failure of crew members to fully understand the fault on engines, rarely, but it happens, the crew can misjudge the engine on fire, shutting down the good one. On airlines where you fly, is there any standard procedure to avoid this event, I mean, shutting the good engine, instead of the bad one?


texts: Does Smeaton's coefficient have a modern accepted value or it is dependent of the air density?

texts:
Does Smeaton's coefficient, k, have a modern value or it is
dependent of the air density?
Why is the accepted value of k so high?

In various texts about the Wright brothers (see 1 and 2) one can read about Smeaton's coefficient that troubled them a lot and that they finally discovered the parameter had a much lower value reaching the conclusion $k = 0.0033 lbf/ft^2/mph^2 = 0.79 kg/m^3$ (instead of $k = 0.005$), a fact also noticed by others before them.

"the Wright brothers calculated a new average value of 0.0033.
Modern aerodynamicists have confirmed this figure to be accurate
within a few percent." Source: Correcting Smeaton's
Coefficient
$L = k \cdot  S \cdot V^2 \cdot C_L$

$L$ = lift in pounds

$k$ = coefficient of air pressure (Smeaton coefficient)

$S$ = total area of lifting surface in square feet

$V$ = velocity (headwind plus ground speed) in miles per hour

$C_L$ = coefficient of lift (varies with wing shape)"

Source: The Wiki page of the Wright brothers

However, knowing that the modern formula for lift is
$$L = 0.5 \cdot \rho \cdot S \cdot V^2 \cdot C_L$$
Where $\rho$ = the air density.

It appears that $k = 0.5 \cdot \rho$ and so it does not have a standard average value. Also a $k = 0.0033 lbf/ft^2/mph^2 = 0.79 kg/m^3$ leads to a $\rho = k/0.5 = 1.58 kg/m^3$ that corresponds to a sea level air temperature well below -25 C, which is unusual.

If the two relations for lift are correct, the Smeaton's coefficient can not be 0.0033 but closer to 0.0025 a value corresponding to a standard air density at $20 ^\circ C$ close to $1.2 kg/m^3$.


texts: What security clearances does a foreign citizen doing a flying course in the United States have to pass?

texts: I remember reading that the security for foreigners doing a flying license in the United States were rigorous (as would be expected). As a European Union citizen, what would I expect to need to do from a paperwork/legal standpoint (FAA, CBP etc.) to be allowed to pursue a private licence in the USA, assuming I have no previous flying experience?


texts: What is the rationale of a weight/passenger value for the ICAO TCAS requirement?

texts:
What is the rationale for the figures 5,700 Kg and 19 passengers?

Excerpt from TCAS's Wikipedia entry page:

  It is a type of airborne collision avoidance system mandated by the
  International Civil Aviation Organization to be fitted to all aircraft
  with a maximum take-off mass (MTOM) of over 5,700 kg (12,600 lb) or
  authorized to carry more than 19 passengers.


texts: Do similar angles on a plane make it more stealthy?

texts:
I learned in my intro to engineering class at my college that 5th gen fighters (which are stealth aircraft) are designed with similar angles to evade radar.

Why is this true?

Also, does the angle matter?  Many of these modern fighters looks to have very similar angles (no pun intended).


texts: Why should AKE LD3s not be used in the A380?

texts: I noticed some LD3 ULDs (Unit load device, container type LD3) - like AKE (LD3 without forklift holes/half ALF) - mention DO NOT USE A380. What is the difference between normal LD3 and A380 LD3?


texts: What is the difference between CAMO and CAME?

texts: Could someone explain the difference between a Continuing Airworthiness Management Exposition CAME and a Continuing Airworthiness Management Organization CAMO?


texts: Where can I get aviation weather information?

texts:
Where can I get weather information (preferably something similar to what pilots get) for a non-pilot?

I usually use flightradar24 for flight tracking, would love to see weather data as well.


texts: How does Integrated Modular Avionics (IMA) improve reliability and obsolescence mitigation over the federated architecture?

texts:
I've been researching this question on why IMA is more reliable, and the common answer seems to be because of the robust partitioning which is reliable and can prevent software fault propagation.
But how is it more reliable? Wouldn't sharing of hardware resources create more dependencies for these systems?
How does IMA prevent obsolescence comparing it to federated architecture?


texts:
I notice the term LNAV engagement being frequently mentioned in aviation related discussions or in several FAA's relevant material. Take, for example, this quote from Order 8260.58A (PBN Instrument Procedure Design) which states:

  Order 8260.58A [5-1]: The ICA must be long enough to allow LNAV engagement (500 feet above airport elevation).

I am aware that LNAV means "Lateral NAVigation" but I have some trouble understanding what does "engagement" exactly mean and why an aircraft have to climb at 500 feet above airport's elevation before the initial turn for this engagement to happen. Could someone point me in the right direction?


texts: What is the pattern of the flashing light in Airbus A340-300?

texts:
I'm looking for the lights and flashing patterns of the Airbus A340-313 (or any Airbus A340).

My question is related to this one: Do lights on aircraft flash in a specific pattern?

but is very specific for this model.

In any case I'll be grateful is there is some page or link with the patterns of several models (so I don't have to disturb you in the future :) )

Thanks in advance.


texts: How to get the correct speed/power on downwind?

texts:
(Note: in this example I'm taking speeds from a Cessna 172)

I was taught that on downwind, you fly at pattern altitude at a normal power setting until you beam the numbers, at which you reduce power (to 1800 RPM.. ish) and start your descent. I was also told that the speed of each leg of the descent should be 80 (downwind), 70 (crosswind), and 60 (on final), and you add 10° of flaps each leg.

I'm running into two related problems:

On downwind, my airspeed can be 100-100 knots. This means I float for awhile at pattern altitude after beaming the numbers to get my airspeed down before starting the descent. I can't extend flaps until I'm under 80 knots and in the white arc.
My goal is not to add power after I've taken it out. Idea is to control the landing enough that I can still make the runway during an engine out. If I reduce the power a lot to hit 80 knots, I end up having to add a bunch of power on final to make the runway. If I keep the nose high and drop airspeed after beaming the numbers, I end up floating too far away before starting my descent, causing me to fly a larger pattern, and the need to add power to make the runway.

How do I control the speed and power setting to have a graceful pattern and smooth power setting while landing?


texts: What IFR clearances may a pilot obtain from ATC directly without a pre-filed flight plan with FSS?

texts:
I have known two types IFR clearance that a pilot may request with flight plan filing.

Pop-up clearance: A pilot on VFR requests an IFR clearance to destination airport. ATC grants a clearance on a work-load permit basis.
IFR Climb to VFR-on-top: A pilot may obtain this type of clearance from ground clearance delivery and the clearance limit is usually a nearby Nav aid.

The unlikely clearance without pre-filed plan is,

Airport-to-airport: Ask ground clearance delivery for an IFR clearance to another airport.

What other types of IFR clearance else may I request ATC directly? We know that the flight plan checked-in time needs to 30 min prior to its start time.

Another example is

"IFR-descent-to-VFR-under-bottom": Is it possible to request an IFR descent through a cloud layer, say 8000 to 5000 through a layer 6000~7000? Is it just one special case of "pop-up clearance", or due to the descent nature, ATC won't grant it?

Are there any concrete regulations or general conventions that a pilot may follow?


texts: Structural rating of aircraft to withstand storm induced structural stresses

texts:
I was watching an accident report where an aircraft crashes when  a storm destroys a wing spar.

I'm curious is this only a danger for small aircraft or are there situations when a storm has caused  structural damage to large commercial aircraft?

Even among smaller aircraft are different models built to withstand different limits of such storm induced structural stresses & what would be the metric to compare them by?


texts: Helicopter Flight: What is the reason for decrease in Induced drag with increase in speed?

texts:
As per the figure the induced drag will decrease only if the AoA of the blade is decreased — But in the forward flight, cyclic input increases and decreases the AoA throughout the blade rotation cycle.

Also, in forward flight, a component of the Lift force is used to compensate for the parasite drag, so the overall Lift vector will increase. This should increase the induced drag further.

Where I am getting wrong? What causes Induced drag to decrease with an increase in speed?


texts: Why does a steady-state non-zero body yaw and/ or roll rate induce side force?

texts:
An answer on ASE states

The presence of steady-state non-zero body yaw and roll rate induces side force ($C_{y_p}$ and $C_{y_r}$).

What is a non-mathematical explanation of why this is so?
Is it correct to say that the side force components described above would exist even if the body were somehow following the same trajectory, and experiencing the same yaw and roll rotation rates, in a vacuum?  I.e., that they do not directly stem from aerodynamic effects?
Also, do the sideforce components created by a non-zero body yaw and/ or roll rate depend upon at what physical location on the aircraft we are measuring the sideforce, i.e. upon exactly where the slip-skid ball (inclinometer) is located?  If so, might there be a location where the measured sideforce resulting from the yaw and/or roll rate is zero even though the aircraft is yawing and/or rolling?


texts: How do pilots rest on long-haul flights?

texts: When flying on a long-haul airliner flight in economy, often I find it very hard to fall asleep. However, when off cockpit duties, they still have to get rest so that they are able to control the aircraft without being exhausted and collapsing on the controls when they are on duty. Are there are any specific methods of helping pilots to gain the rest required on board an aircraft? Have there been any studies about the effectiveness of these?


texts:
Jet lag, medically referred to as desynchronosis and rarely as
  circadian dysrhythmia, is a physiological condition which results from
  alterations to the body's circadian rhythms resulting from rapid
  long-distance trans-meridian (east–west or west–east) travel on
  high-speed aircraft. For example, someone travelling from New York to
  California feels as if the time were three hours later than local
  time. (Source)

As pilots often have to travel between multiple time-zones, especially during long haul flights, with as much as 12 hours of difference between them, how do they fight jet lag?


texts:
My father used to work as an air traffic controller, and often I heard mention of a 'running rabbit'.

Obviously, vermin on the runways of airports can be a bad thing, but I don't think he was literally talking about animals.


texts: Why is a aerofoil modeled by attached torsional and linear spring in a  wing flutter analysis.The model does not even satisfy the boundary condition of zero displacement of wing at point of attachment to fuselage. I am considering the pitch plunge model as shown in figure.


texts: On Air France 447, what would have been the lowest altitude to initiate recovery after the stall developed?

texts:
What could the lowest altitude of Air France 447 have been to recover the (stalled) flight, where the co-pilot informed the captain that he was pulling up the whole time?

The co-pilot didn't inform the captain until 2000 feet, which obviously was too low.


texts: Is true altitude vertical separation between airplanes dependent on temperature?

texts:
Does the "true" altitude vertical separation between airplanes (using the same altimeter setting) vary as the temperature changes?

( I fully realize that the "true" altitude of both airplanes is lower when it's colder than ISA and higher when it's warmer than ISA)


texts: How is the cargo hold volume for passenger aircraft designed?

texts: An A380 has up to 2 decks for passengers and only 1 deck for cargo (for passenger's luggage), whereas a B777 has 1 deck for passengers and 1 deck for luggages. It looks like the volume of luggage per passenger is reduced in a A380 compared to a B777. Is that true? Is the volume of luggage per passenger the same? Is there a method to calculate the volume of the cargo and then to design its shape?


texts: Is it possible for a modified hang glider to land safely coming from orbit?

texts: Can a glider be dropped from geosynchronous or other orbits and safely land?


texts: Why would a jet engine that runs at temps excess of 2000°C burn when it crashes?

texts:
Airline engines are designed to work at very high temperatures. Yet, when a plane crashes they're burnt (see below). Is it something in their design?

(bostonherald.com)


texts: What's the purpose of airline CREW tags?

texts:
I see it sometimes on airline crew luggage, but not always. I see these come with airline name, sometimes airline base code and large CREW.

What is the purpose of these airline crew tags? After all, I got one in Crew Outfitters store as "collectible". Is this official airline tag which gives priority, different way of airport handling or something?

What would happen if I put it on my suitcase (either checked or carry-on).


texts: Why are Stratolaunch's engines so far forward?

texts: Stratolaunch's engines hang from pylons, not under the wing, but entirely forward of the wing's leading edge.  (Even farther forward than, say, the 747's.)  What benefit does this have, to compensate for the heavier pylons?


texts: How to modify an amateur kit build with wing hard points

texts:
I plan on modifying an amateur-built all-metal kit plane so it has a hard point under each wing where various external loads (cameras, probes, etc) can be fitted to (university research). The location would be approximately mid-wing. The aircraft in question is a Sling 2. It will be registered in Germany as an experimental with a permit-to-fly.

I was unable find any resources on how to tackle this engineering problem on small aircraft. The resources I have access to are all for large aircraft and are somewhat "oversized" in my opinion.

We are talking external loads up to about 5 kg (11 lbs) in mass.

An aerodynamic envelope expansion will be needed for each external load but how do I design the wing for it?

Edit: I found a builders log of a 75% Tucano-R Replica who did this, however there is no explanation on the engineering part. It looks relatively straightforward with just two thicker plates attached to a rib.


texts:
I can understand what function(s) the flaps serve, but how are they controlled from an internal perspective? Does flipping the switch send signals to an electrical servo? Or is it hydraulics? How are these devices attached to the main wing body, and if they use hinges (which they probably do) where do the hinges connect to? Do these devices have "Control Horns" and "Push-rods" like RC Planes? This can also be generalised to apply to ailerons and rudders too.

EDIT: I'm primarily referring to small GA planes like the C172 and the PA-28 - So while I'd like to hear about air-liners too, I primarily want to know about its implementation in GA aircraft.


texts: What materials are used to build a military runway?

texts: What type of matrix should be used on a military runway used by C130 aircraft?


texts: Why doesn't the flight path angle increase beyond a certain angle even if the angle of attack is increased?

texts:
From level flight, when the angle of attack is increased the flight path angle increases (the aircraft starts to climb). What causes the aircraft to stop to increase its angle of climb (angle between the horizon and the speed vector) as I continue increasing AoA at full thrust?
Is the effect described in Paragaraph 1 the same as with steepening the descent at idle thrust when I pull the stick?
Is it right that the critical AoA, above which continuing to pull the stick  causes decreasing speed vector's angle (i.e. "going down instead of up"), is the same for climb and descent and corresponds to $V_X$ (best angle of climb speed) up to negligible corrections?

Thanks
Alex


texts: Why is the F-104 Starfighter’s afterburner thrust not greatly impacted by altitude?

texts:
Here is a page from the F-104 flight manual. It shows the flight envelope for the F-104 Starfighter with the powerful J79-GE-19 turbojet engine:

I have a question regarding the shape of the afterburner envelope.
In Aerodynamics for Naval Aviators, published in 1965, the author, Hugh Harrison Hurt, Jr., states:

The thrust added by the afterburner of a turbojet engine is not
affected so greatly by altitude as the basic engine thrust. The use of
afterburner may provide a thrust increase of 50 percent at low
altitude or as much as 100 percent at high altitude.

Why is military thrust (basic engine thrust) greatly impacted by altitude, and afterburner thrust is not?


texts: In what way are the airfoils used for a propeller different from the ones used in turbofan engine?

texts: Airfoils are used in the blades of a propeller as well as the blades of the fan, axial compressor and turbine in a turbofan engine. Thus, the airfoils used in above two applications have different purposes. In propeller, the lift from the airfoil is used for generating thrust. Whereas, in a turbofan engine, airfoils are used for adding and extracting work from the flow in the compressor and turbine sections respectively. Therefore, my question is what are the characteristics of the airfoils employed in both propeller and turbofan engine, and how they vary from each other. Also, how different is the blade section of a fan with respect to the ones in axial compressor and turbine.


texts: Strut braced or wire braced airplane wings?

texts: For an ultralight (or other airplane designed for slow flight), would a strut-braced or wire-braced wing be more efficient aerodynamically?


texts: How do I do these VOR time and distance calculations?

texts:
I'm trying to figure out the calculation to these questions:

  A pilot tracking a VOR turns 90 degrees from current heading. The
  pilot notes that it takes 3.0 minutes for the plane to intercept the
  radial 5 degrees from where it previously was. What is the time to
  VOR?

And:

  Using the previous question, what is the aircraft speed if the
  distance to travel is 100 miles?

I used the formulas my professor gave me and the numbers are coming out unrealistic to me. Could someone walk me through how to get the correct answer?


texts: Is my understanding of a gas turbine engine compressor correct?

texts:
So I understand that the rotors add dynamic pressure to the airflow and this dynamic pressure airflow is transformed into static pressure in the stator vanes. But now does the airflow still have dynamic pressure once it leaves the stator vanes, or does it get completely transferred into static pressure?

And the static pressure stays in the airflow and keeps increasing as it goes on, it doesn't get transformed into dynamic pressure because the movement of the rotor vanes create the dynamic pressure, is that correct?


texts:
I once had a dream of becoming a helicopter pilot. Then life happened: married young, kids, school, career, etc. I'm working in a good career while finishing a Ph.D. in engineering. But still, I find myself wondering "what if?"

My dad was in a similar situation when he was my age (33) when he started flying (and selling to pay for the habit of flying) powered parachutes. I soloed for the first time in a PPC at 10-years-old and have hundreds of unlogged flight hours. Not a helicopter, but still, some flying experience and lots of good memories.

So my question that isn't career advice: what are the paths for getting into a helicopter flight career? And, are there any routes for people like me?

Military? Probably too late for me. I've heard that there are age restrictions but I'm not certain regarding the specifics. Others may be interested, though.
Local flight school? I'm hesitant. I know people who have gotten burned by the flight schools at local airports when the school closed and the owners disappeared with their money. These seem sort of like a Ponzi scheme anyway, IMO, since once you become an instructor, you train others, who are also becoming instructors, who are also... turtles all the way down...
Commercial Flight School?

Are there any grey-beards out there who can offer some perspective on the three options? Or offer other alternatives?


texts: What is the relation between aircraft altitude and ADS-B coverage?

texts:
While reading the description of ADS-B given on the FR24 website (ADS-B How it works), I came across this sentence:

  The farther away from the receiver an aircraft is flying, the higher it must fly to be covered by the receiver.

What is the relation between height and coverage in this case?


texts: Can control surfaces for slow aircraft be 3D printed?

texts:
Can control surfaces for slow aircraft be 3D printed or even just printed as a core and then wrapped in fibreglass or carbon fibre?
I understand that 3D printing of wings, etc. is pretty common in the RC Aircraft world.
What about for slow flying aircraft such as Ultralights, etc.
In Rutan's book, "Moldless Composite Sandwich Aircraft Construction", Rutan strictly notes that only certain foams can be used as a core for structural components. Other foams are just for shaping of non-structural components such as interior panels, etc.
I assume there are certain engineering/material properties of the structural components that need to be met such as flexibility, no delamination, no structural degradation, high number of loading cycles, etc.
The question is, do any 3D printed materials meet these engineering/material properties.
Any help would be appreciated.


texts: What is the wording on outline of Wright Flyer on FAA pilot license?

texts:
I was told once that the outline of the Wright Flyer was taken from a speech given by the Wright Brothers.  In the picture below you can very clearly see the words on the Wright Flyer.  Does anybody know what that speech was?

Picture taken from Wikipedia Commons

Picture taken from Keven's Aviation Adventure


texts:
Anybody knows what is this outlet for and why it is designed in such way?

Edit: On MD-90 didn't see such thingy


texts: On modern fighter aircraft, why do most carry a rotary cannon when they tend to have little use against aircraft?

texts: I understand that in multirole or strike aircraft the cannon has a CAS use, but on a purely fighter aircraft, does the benefit of a fallback weapon outweigh the handicap of added weight?


texts: Does the a320 neo have anything like MCAS?

texts:
I am trying to book a flight that will be on an A320 NEO.

Does this have any 'new' systems or features, like the MAX MCAS system?

I'm asking this question also because one airline has just grounded it's NEOs...


texts: Why does the spanwise flow along a swept wing not accelerate?

texts: I read this article explaining flow around a fixed-sweep swept wing, and it stated that the spanwise flow component does not accelerate, but the chordwise flow component does. What is so special about spanwise flow that it does not accelerate?


texts: Can an ultralight aircraft fly with a 18hp engine?

texts:
I have some questions - I'm planning on building single seat UL aircraft with this plan sketch (I have more), I drew this based on real plain and some research. Empty weight is between 50-70kg with engine

The power plant I will use this engine. 4 stroke, OHV, single cylinder, 440cc, power 18hp/3600 RPM, torque 3.0 kgm/2500 RPM (21.7 lb ft), ignition TCI, gross weight 37 Kg.

My questions:

Is this engine enough to make it fly?
Do I need belt reduction or gear reduction for a 1 meter propeller?
What propeller size to fit with this engine?
Do you see any problems with this design?

https://en.wikipedia.org/wiki/AmEagle_American_Eaglet

I found this on Wikipedia, it use a McCulloch MC101 15HP engine with 9000 RPM, that's make me doubt to use SFE 460 because the RPM far bellow. I can't find McCulloch MC101 here


texts: Is the pilot required to keep visual lookout during IFR operations in VMC?

texts:
During VFR operations, the pilot must always self-assure separation from other aircraft, and thus must maintain a visual lookout all the time.

For IFR operations but in VMC, are there any rules as to pilot visual lookout? Is the pilot still required to maintain visual lookout (might be difficult in clouds, though...). Even if ATC assures separation, some objects such as drones may not be known to ATC, so ATC cannot provide separation...


texts: Was the Hughes H-4 Hercules capable of flying out of ground effect?

texts: According to the wikipedia article the Hughes H-4 Hercules (Spruce Goose) reached a maximum altitude of 70 feet on its flight.  At this altitude the aircraft was still in ground effect.  Would the H-4 have been capable of flying out of ground effect?  Why or why not?


texts: Does the P&W F100 turbofan engine of the F-16 really produce this much power?

texts:
I've been trying to calculate the power a P&W F100 engine on a F-16 is producing using some of the available data on thrust and velocity and I ended up with a number that I want to confirm. Here's how I made the calculations.

First of all, I don't want my calculations to involve any complications due to the altitude and its effect on the engine thrust, so I just chose to make my calculations at sea level. Wikipedia states that the maximum speed of an F-16 at sea level is 1,470 $km/h $ which is ~$408$ $m/s$.

Secondly, I found out that jet engines in general produce different thrust at different speeds. I did some research and found that turbojets produce somewhat  constant thrust at subsonic speeds and gain extra thrust at supersonic speeds, while turbofans suffer degrading thrust with speed with a degree depending on the bypass ratio of the turbofan. I found that high bypass ratio turbofans suffer much more thrust degradation at high speeds compared to low bypass ratio turbofans. which means that low BPR turbofans fall somewhere in between the turbojet and high BPR turbofans according to their BPR.

I found that P&W F100 Wiki gives a bypass ratio of $0.36:1$, then looking at this thrust vs speed graph, which confirms what I concluded above, I could determine that the F100 engine with 0.36 BPR can have no more than 10% thrust degradation at mach 1.2. I also think that using the afterburner shifts the curve further up since more air is now entering the core than before without increasing the fan flow and therefore the engine behaves even more like a turbojet than a turbofan. Overall, I think it would be safe to say that the afterburner thrust at Mach 1.2 at sea level will not degrade more than 10% and so the F100 engine thrust will become 0.9×127 kN = $114.3$ $kN$

Now the power is simply $P = F . v$ = $(114.3 × 10^3) × 408$ = $46.6 × 10^6$ $W$ or about $62,000$ $hp$.

So my question now is: Are my calculations acceptable to a certain degree or are they completely off and I didn't take into account another significant factor?

EDIT: I have another question. I'm assuming here that the engine is producing full thrust at the sea level to counter the air drag and achieve the quoted speed. But is this a correct assumption? In other words, could an F-16 fly at its maximum speed at sea level while not using the maximum thrust?


texts: How does the FOVE system work with the Airbus FMS?

texts:
The Flight Operations Versatile Environment (FOVE) is a separate software system used with Airbus aircraft by dispatchers to determine performance data to enter into the FMS. There seems to be little info on the interwebs about it.

Since the FMS takes the parameters and makes its own calculations, I'm not sure why a separate system is needed. A U.K. CAA bulletin says:

  "As [FOVE] gives more accurate performance figures it is generally used on occasions where takeoff performance is more limiting."

In what way does it produce more accurate figures than the aircraft's own FMS? Is FOVE created by Airbus or a third party? If it's third party, has Airbus approved it?

How does FOVE work with the FMS? Do they just override the FMS calculations, or does it give them alternate data to enter into the FMS to create the required parameters?


texts: When did the military/Air Force start measuring fuel in pounds instead of gallons?

texts: Watching a training film for the B-47 from 1951, they mention (around 12:30) that the fuel is now measured in pounds instead of gallons on the instruments.   Was that a new concept with jet aircraft?  Did previous propeller aircraft instruments always measure gallons instead?


texts: Are air traffic controllers required to obtain a pilot license?

texts:
Here in my home country (Hong Kong), all air traffic controllers are required  to obtain a PPL as part of their training. The reason being, if the controllers can better imagine a pilot's perspective, they can better accommodate and provide assistance to pilots. I don't think they are required to keep the license current, but sure they need to pass all PPL exams.

Is this requirement common around the world? (Note that I intentionally do not specify which country or jurisdiction. I'm looking for an answer which lists the countries which have this requirement.)


texts: What max Mach number of the blade tips on Concorde's engines?

texts: What was the maximum velocity and Mach speed of blade tips in Concorde's engines?


texts: What is the use of this remove before flight cover on the nose of a Bombardier Global 6000?

texts:
I recently saw a Bombardier Global 6000 at my local airport. I was just wondering what the use of this circled remove before flight cover on the nose of the Bombardier Global 6000 is. I never saw such covers before on a aircraft. What is the cover covering and why are the 3 ones connected with a wire?

(Own work)


texts: Does the A320 autopilot work in flight with both engines off?

texts:
For a series of simulator sessions to determine the speed polar with students we plan to cutoff both engines in our A320 simulator, but we still want to use the autopilot to control speed (in theory, the autopilot would adjust pitch to keep a desired speed). Obviously, some modes, like altitude hold, positive vertical speed and autothrottle modes will not make sense in such a scenario.

In a real A320, can the autopilot (or selected functions only?) be used (activated) when both engines are cut off? (for example, after a double bird strike)? Assume APU running, so electrical power is guaranteed.


texts: What is the advantage of the two-part rudder and how does it work?

texts:
I saw that some aircraft's rudder is composed of an upper rudder and a lower rudder (B727, A380, ...) as illustrated:

Image Source

I wonder how does it work compare to a normal rudder and what are the pros and cons of the two-parts rudder over the one-part rudder?


texts: What happens when all passengers jump at once?

texts:
As a thought experiment, imagine a plane with minimal fuel/appliances on board with hundreds of heavy passengers that make up say 10% of the weight of the plane.

Now imagine that they have a way to synchronize a jump where temporarily for 0.5s they are airborne in relation to the plane.

(NOTE: If idea of so many heavy passengers is troublesome to you, assume this is a cargo carrier with spring loaded "widgets" that have ability to be programmed to "jump" at once.)

Questions:

Can flight dynamics be affected due to the jump at ANY phase of the flight?
What % of the typical (cargo/passanger) plane weight is the actual cargo (excluding fuel)?
Does the location of the "jumping" cargo matter?  Tail vs. Cockpit
What happens if all pax/cargo suddenly jumped to tail or cockpit section?

Everybody jump!


texts: Is it possible for a plane to be over fueled (and over-weight) to take off?

texts:
I've just reached my destination after 33 hours going from one European hub to another. A journey which usually takes a max of 6 from leaving my house!

On the final leg of the journey, after boarding, the pilot asked for volunteers to leave the plane as they were too heavy to take off.

They had flown a 50 min flight from my final destination to where I was and, without fuelling, were turning around to go back. They were adamant that the plane was too heavy and (with a print out from one of the flight computers in hand) were asking for 27 people to leave the flight.

Is this possible? Because the MTOW of the aircraft is greater than the max landing weight, how could they have landed under max landing weight but now be too heavy to take off?

Maybe they flew with no passengers, but exceeded MTOW after adding more passengers and luggage?

Any suggestions for question re-phrasing or additional clarity are greatly appreciated.


texts: What are the differences between FADEC and EEC systems?

texts:
Can anyone differentiate FADEC and EEC system in an aircraft Engines?

As I was working related to Engine controlling. I got confused of FADEC and EECs.
As per some of the doc. I read like EECs are a part of FADEC.


texts:
According to the VNC, the MEF represents the highest feature in each quadrangle. It refers to

AIM RAC 5.4 and CAR 602.15(2b) which basically says "lower than 500 AGL (CAR 602.14(2b)) ok, when for aerial application or aerial inspection, photography, ..."
AIM AIR 1.5 which is about "Pressure Altitude" which I guess is because the heights are ASL

Now, the sample quadrangle here shows a MEF of 2700'. Looking at that quadrangle, the highest obstacle I would say is the mountain in the very east, north of 50°35' which is 2290' high. I wonder where that difference comes from.

I think that both figures, 2700' MEF and 2290' are ASL. Therefore it can't be the difference between ASL and AGL.
It always seems to be ~400' more than the highest feature.


texts: From what I understand, in jet engines, air is compressed and fuel is not only injected but also ignited : how is this done ?


texts: Why is there a difference between aileron upwards and downwards deflection angles?

texts:
I have noticed that on airliners the ailerons have different angles if deflecting upwards than deflecting downwards. When deflected at the maximum angle maximum angle downwards is lower than when deflected upwards. I suppose that this is due to the fact that when the wing has to be deflected upwards and consequently the aileron moves downwards, the force required is lower as there is already lift being produced by the wing whereas the opposite would happen when deflecting the wing downwards and more power is required.

Is this assumption true or are there any other technical reasons behind this deflection angle difference?


texts: What's the rule of thumb for power and rpm in a constant speed prop?

texts:
I think I understand the relationship between the power lever and the RPM lever in an aircraft with a constant speed prop thanks to this question. However, what'd be a general rule of thumb for flying a small aircraft (e.g. Cessna 170) that has a variable-pitch propeller?

Edit:
I'm flying a Cessna 170 that has been modified to fit a constant speed prop. What I'm trying to determine are the general recommendations for flying with them. Things like: On takeoff you should use full power & full rpms, on cruise lower power to 75% but keep full  rpms, etc. I'm not sure if there are general recommendations to begin with.


texts: Can I land on an abandoned runway in California?

texts:
Can a private pilot land on an abandoned runway in southern California's remote areas?

There are a few unpaved runways near scenic hillsides, ideal for camping or swimming.


texts: Where can the ICAO recommendations be found?

texts:
ICAO issues recommendations/rules/statutes/something? that standardizes the regulations for international air travel world-wide.

What are these "rules" officially called and where can they be found?  Are they available on the internet?


texts: How did this air force plane likely get into the eye of Hurricane Florence?

texts:
The annotation for this CNN video says

Air Force plane flies into Hurricane Florence
Watch as a US Air Force plane flies into the eye of Hurricane Florence to collect weather data for the National Hurricane Center. Source: CNN

But I can't find any information on what kind of plane this is nor how it safely got into the eye in order to record this.
Would they generally fly through the storm at this altitude, or do they fly above it to reach the eye, then "drop down" into the eye?
The video is also viewable here where the footage is between 00:24 and 00:40.


texts: Why do some helicopters have the tail rotor mounted higher than the tailboom?

texts:
Why do some helicopters have the tail rotor mounted high above the tailboom, whereas others have it at the end of the tail boom?

Above the tailboom:

Wiki Commons

At the end of the tailboom:

Boeing.com

I know the reason for having tail rotors, that's not the question at all. I am just curious as to whether the heavier helicopters have different torque counter requirements than the lighter ones?

Generally I notice that the heavier ones have the tail rotor mounted higher up and the lighter ones have it on the boom.

In R/C almost all of the 3D  models have the tail rotor at the same level as the tailboom.


texts: What is this air-scoop behind the cockpit of the Polikarpov I-153 and Stearman?

texts:
(Source)

There is a Ferrari-looking air-scoop behind the cockpit of the I-153 and most of the Stearman planes too.

What is that?


texts: What are typical insurance costs for airliners?

texts:
What are typical insurance costs for airliners, and how are they arrived at?

Factors that might be relevant are hours flown, number of landings/takeoffs per year, total hours of airframe and engines, hours on type for the pilot in command, etc. - but are they considered, and how?

Also, are long-haul flights treated differently than short-haul?

Obviously, each specific contract is covered by commercial confidentiality, but some baseline estimates should be available somewhere.


texts: Is there a clear or particular pattern in the mistake-making that leads to a landing at the wrong airport?

texts:
I'm interested in how decisions and mistakes are made in the cockpit.
According to a brief news report about a recent landing at the wrong airport (see also the Aviation Herald report):

Landings at wrong airports by commercial pilots, while unusual, are still more common than many passengers may realize or airlines would like to acknowledge.
An Associated Press search two years ago of government safety data and news reports since the early 1990s found at least 150 flights in which US commercial passenger and cargo planes have either landed at the wrong airport or started to land and realized their mistake in time.
In most cases, the pilots were cleared by controllers to fly based on what they could see rather than relying on automation. Many incidents occurred at night, with pilots reporting they were attracted by the runway lights of the first airport they saw during descent. Some pilots said they disregarded navigation equipment that showed their planes slightly off course because the information didn’t match what they were seeing through their windows – a runway straight ahead.

Is there a clear pattern in the decision-making process that leads to such landings?
For example:

Does the transition from automated or instrument flight to visual flight represent a vulnerable point in cockpit management?
Is this phase of flight (perhaps after a long day) associated with moments of pilot inattention?
Are there issues in the relationship that a flight crew has with navigational equipment that allow it to be 'disregarded' in this way?

I don't know if any of these are actually involved, they're just examples that I'm suggesting because I'd like a deeper answer than "sometimes pilots are inattentive".


texts: What is the function of interplane strut of a Biplane?

texts:
What kind of load does the interplane strut(s) carry,is it compression, tension or shear?
In order words,what's their function and how do you calculate the force that the interplane strut carries?


texts: Are there any known incidents of ejections by capsule? What are the survival chances?

texts:
One hears of many stories of ejection seats but rarely of ejection by capsule. Probably because seats are so much more common.

So are there any known incidents of ejections by capsule? F-111 was one such aircraft that had an ejection capsule I recall.


texts: Can an aircraft re-pressurize at high altitude?

texts:
When parachute jumps are performed from 32000 feet (or between 28000 - 30000 feet), once the jumpers are let out from the aft (cargo area), does the aircraft need to change altitude (e.g. descent)? Can the crew not pressurise the aircraft by simply closing the door?

In particular, I am talking about wide body aircraft with cargo deployment facility.


texts: What are the takeoff and landing speeds of a Learjet 45?

texts:
I am a fairly new enthusiast to flight simulation.

I would like to know what are the takeoff and landing speeds of a Learjet 45? If they are not fixed, what factors influence those speeds?


texts: How serious is an impact like the 10/2017 Delta Airlines suspected bird strike?

texts:
Recently, there was an incident where a Delta Airlines charter flight carrying the Oklahoma City Thunder basketball team was struck by an "unidentified object". Delta's official statement claims that

  Delta flight 8935, operating from Minneapolis to Chicago-Midway as a charter flight for the Oklahoma City Thunder, likely encountered a bird while on descent into Chicago. The aircraft, a Boeing 757-200, landed safely without incident; customers have since deplaned and maintenance teams are evaluating.

While I do not agree with the UFO label that this story seems to have run with, I am shocked that a bird (especially at such an altitude) could cause such severe damage to the nose cone (even at such speeds).

Is this characteristic of a bird strike and how severe would this incident have been had the collision been with the windshield?


texts: Why are pilots deemed unfit to fly after emergency ejection?

texts: There are many instances where pilots need to eject out of the cockpit due to emergency situations, and after such an ejection from some modern aircraft, pilots are deemed unfit to fly airplanes for some years. Why is this done? What is the minimum number of years after which a pilot is deemed fit to fly again?


texts: Is a 100 hour inspection required for an aircraft to be used in a checkride?

texts:
Is a 100 hour inspection required when renting an aircraft for a practical test with a DPE, to whom you are paying a fee?

Lots of money is being exchanged, yet the DPE told me that it is not "For Hire" because the money is going to him (i.e. he's not paying me, I'm paying him). How can the direction that the funds are traveling in affect the meaning of the term "for hire"?


texts: What are the implications to consider when starting a university Flight Club?

texts:
I'm currently a University student in the United States, and finishing my PPL within the next two weeks (assuming I pass my checkride!)

Unfortunately, when I return to University for the Fall semester, there are zero flying resources. No local clubs, or anything of that nature. I am told by many of the pilots around my out of state flight school about their student flying clubs back in college, and it sounds amazing.

My University encourages students to start clubs, offering a maximum funding of $10,000 - $50,000. I presume because clubs increase the schools admission, it is worth the money for them? Being a large engineering school, I could see it being a selling point in tours.

My question is in three parts.

What are the implications of starting a student Flight/Aviators Club, and what benefits could it provide, outside of meeting new aviation friends? (Implications referring to expected safety precautions a school might want to impose, any FAA regulations pertinent to a club, and associations/partnerships we could create to show legitimacy to the school)
What would be a good way to find pilots within the University? (I'm sure out of 30,000 students there are some)
Would this be percieved by the general aviation community as "not my place" to start a student flying club, as I am a new pilot?


texts: Why are adjustable area jet engine nozzles mostly limited to military use?

texts:
It seems that only jet engines with afterburners use adjustable area nozzles (this means adjusting the area of the nozzle but not necessarily the direction). This includes most fighter jets, as well as bombers like the B-1B and Tu-160. Outside of the military or afterburning engines, they don't seem to be used, even for smaller engines.

What is the reason for this? Is the Variable Area Fan Nozzle (VAFN) concept related?

Wikipedia explains that it is related to supersonic operation; I'm looking for a more detailed explanation about the reasons for this.


texts: How is the compliance time in this AD interpreted?

texts:
Within 25 flight hours (FH) after the effective date of this AD, or
  within 100 FH since the last inspection, whichever occurs later, and
  thereafter at intervals not to exceed 100 FH

Do we have the same condition in both states of above? If our A/C inspected since the last inspection in 100 FH over or less because of this state "whichever occurs later", we must comply for 100 FH grace period and 25 F/H is omitted?


texts: What is the lift-to-weight ratio during takeoff for an ultralight?

texts: Lift to weight ratio at cruise is 1:1, what is the average lift to weight ratio during takeoff (rotation) of an ultralight with 2m/s as rate of climb?


texts:
From what it appears to me, flight control surfaces seem to be taken for granted. In terms of how they actually work and what kind of physical outputs they give in terms of forces and such.

Take for example the elevators of a Boeing 777, if the pilot wanted to pitch up, the elevators would move up. What are the physics behind this? Is it air being deflected thus a change in momentum occurring to pivot the aircraft's tail down or is the angle of attack changing due to the moving nature of the trailing edge? or both?

I am quite interested to know because I want to simulate Aerodynamical forces in a game I plan to make soon. Diagrams would also be useful but not required. Thanks in advance.


texts: Why isn't tungsten used in supersonic aircraft?

texts: Why isn't Tungsten used in supersonic jets or flights even though it has a High Melting and Boiling point?


texts: When flying on a glide slope, does the G meter show 1G or less?

texts: If your angle of attack in landing pattern is 14 degrees but your vertical velocity is 600 feet/minute, does the HUD show you 1G or not? Why?


texts: Why are there non-standard altitude callouts?

texts:
I just saw a YouTube video with an A340 landing. There were the regular altitude callouts (1000, 500, etc.) until the callout "110". I was quite puzzled by this.

What are the conditions that the automatic callout would call "one hundred and ten" instead of one hundred?

Parenthetically, I'm almost certain - though I can't recall the details right now - that I've also heard a callout "seventy" in some other video, possibly with another plane type.


texts: Why do we still use pilots to fly airplanes?

texts:
With the recent advances in drone and remote control technology, why are there still commercial and military pilots?

I understand that there can be some serious tactical advantages to human pilots in military operations, but for patrol and commercial flights what are the advantages of a human pilot in the aircraft as opposed to a drone or a remotely controlled airplane?


texts: Why do military aircraft use a different kind of aviation fuel?

texts:
Regular airliners use JET A-1 fuel. However, I've seen that military aircraft, i.e., Airforce or Navy; use a different kind of fuel called JP-N, where N is a number.

What is the reason why this happens? If those other fuels have different properties, which are them to be better than the JET A-1 fuel properties?


texts: Why, during a magneto check, does manifold pressure increase as RPM decreases?

texts: When performing a magneto check or exercising the propeller prior to take off (constant speed propeller), you notice that as the rpm drops the manifold pressure rises slightly. Why does the manifold pressure rise?


texts:
The one labeled as "1" in the picture. And I'm having doubts about "2", it is an air supplier for cabin, right? Or am I wrong?

Thank you.


texts: What advantages and disadvantages do tri planes have?

texts:
A triplane, mainly used in WW1 on the german side, was a biplane with 3 wings.

What were the advantages to having more wings?

And, why don't countries use them today?


texts: How do I find all the frequencies for my local TRACON?

texts:
I'd like to program my hand held radio with all frequencies that I can expect to need around my area.  Specifically, I'd like to find an official list of all the frequencies used by the local Tracon facility.

Looking in the Chart Supplement for the primary airport, I get a list of frequencies for approach and departure at that airport.

If I look at charts for airports around the periphery, I can find other frequencies not listed in the supplement for the primary airport.

My example is Salt Lake City.  Outlying airport is Provo Municipal from which you can reach Salt Lake Approach on 118.85.  I'd guess terrain prevents collocation of the 118.85 antenna with the others.

I'd also be interested to know if there are maps available for ATC sectors within facilities.


texts: What is the data size of Hilton Software's WingX Pro 7 app and all of its databases?

texts:
What is the data size of the WingX Pro 7 installation files and databases including the app itself and the VFR Sectional, IFR Low Enroute, IFR High Enroute, and the full "All Charts(IFR)" databases?

I've noticed that the databases for different aviation apps have different sizes. What is the total storage for WingX Pro7 if you select the option to download all of the following databases:

List item
VFR Sections
IFR Low Enroute
IFR High Enroute
All Charts (IFR) - USA

My understanding is that WingX Pro7 uses higher compression than foreflight, leading to smaller database sizes, but I have been unable to find this information on their website, nor have their customer service responded to my email question.

UPDATE: I got my hands on a 16GB iPad Air and installed the latest version (July 2017) of WingX Pro 7 and downloaded all of the databases for the US including VFR and all IFR charts and plates for the Contiguous USA, plus terrain information. The only database I excluded was the High altitude IFR enroute charts. The total storage used by WingX Pro7 on the iPad is reported as 4.62GB.

2nd UPDATE: I finally got a response from HiltonSoftware on this question. They responded as follows:

Support  07/05/2017 at 2:25 PM
To: Devil07
Message body
WingX, fully loaded required 8GB
iOS may require at least 2GB free memory when all App are loaded
Space also has to be allowed for iOS

Support Team


texts: Could I receive flight training in my company's jet, while on company business with passengers?

texts: On occasion I will travel on my company's corporate jet. From a legal/FAA standpoint, are there any regulations against receiving flight training from a CFI with the proper ratings and currency during those flights? I'm a private ASEL pilot, so this would be working on an instrument/multiengine/type rating. And does the answer change if the jet is certified for a single crew member vs requiring 2 pilots? Assume that my employer is ok with this if it's legal.


texts: When will Europe allow phones (to communicate) on planes?

texts: Currently USA has allowed phones to be used in commercial flights, is there a similar ruling coming to Europe or will my mid air Bluetooth battles have to wait?


texts:
In the suburbs of Lisbon today two people were killed because a pilot of a light aircraft (I imagine without retractable landing gear) landed on one beach full of people (it's Summer and the beaches are crowded).

The question immediately arose on the public opinion: can those light aircrafts, with wheels, land safely on water? This aircraft seems to be a Cessna 152.

The other post "What are the risks in landing on a beach vs. shallow waters?" does not solve this question.

Can light aircrafts with no retractable landing gear make an emergency water landing?


texts:
Inspired by building a new drone, I got lost in curiosity.
What if I have a fixed length of rotor blades and a target amount of lift I want to, well, lift. How do you calculate the number of blades?

I have read a lot about disk loading and was intrigued by this answer (https://aviation.stackexchange.com/a/32252/44213) which found a correlation between diskloading and amount of blades (or lift per blade). It made me wonder; is it actually possible to calculate the number of blades? If it matters (and I guess it does) I want to use a naca0012 airfoil.

Searching around I did find the relation between the number of blades and decreasing efficiency/lift per blade when you add a blade. Also the fact that is would be easier to lengthen the blades is something I found. But if lengthening is not an option, how can you actually calculate this? And, to complete the question disturbing me, what effect does a second disk (like the chinook) have on these calculations?

Any help is much appreciated. Any links will be read thoroughly.


texts: NASA's flying telescope SOFIA — How to find flight plans and real time location?

texts:
SOFIA, NASA's Stratospheric Observatory for Infrared Astronomy:

  SOFIA is based on a Boeing 747SP wide-body aircraft that has been modified to include a large door in the aft fuselage that can be opened in flight to allow a 2.5 m (8.2 ft) diameter reflecting telescope access to the sky. This telescope is designed for infrared astronomy observations in the stratosphere at altitudes of about 12 kilometres (41,000 ft). SOFIA's flight capability allows it to rise above almost all of the water vapor in the Earth's atmosphere, which blocks some infrared wavelengths from reaching the ground. At the aircraft's cruising altitude, 85% of the full infrared range will be available. The aircraft can also travel to almost any point on the Earth's surface, allowing observation from the northern and southern hemispheres.

has arrived in Christchurch New Zealand for a period of airborne observations; 1, 2. More about SOFIA can be found at SOFIA Science Center official website.

I know that there were plans to try to observe a rare occultation event, where the asteroid 2014 MU69 around 17-July 2017 will pass in front of a faint star and block out its light. There are predictions (data and maps) shown below, and a cryptic list of SOFIA flight plans can be found here.

You can read more about what's happening in this interesting answer as well as in the original question there. This is important because 2014 MU69 is the next target for the New Horizons spacecraft after its Pluto flyby in July of 2015.

QUESTION: If I wanted to look for official flight plans, and watch for any possibility of near real-time data (even if intermittent) on FR24, how and where could I look up the SOFIA aircraft?

above: predictions from here.

below x2: images from Space.com's Photos from SOFIA, NASA's Flying Telescope (Gallery); click them for full size images.


texts: How can I combine flight training hours flown under various legislations in a single logbook?

texts:
I am a European citizen and last year I went to the US to start flight training. I got my student license and did my FAA private written exam. I logged about 78 flight hours with a flight school.

I also flew several times with an FAA authorized instructor but I never logged those hours because I was flying part 141 and since my flight instructor was under part 61 I was afraid I could not log those hours. I do not have a private license because I had do go back to Europe.

Now I'm back in Europe but I have the chance to fly at Christmas with an instructor in the US (not a flight school). Could I log these hours on my logbook I had started in the US?

And how can I combine my US and European logbooks?


texts: Is the September 11th the only time a plane was crashed into skyscrapers?

texts: I wonder if there has been other plane crashes with skyscrapers in history, except the one of the World Trade Center.


texts: How does an AMRAAM communicate securely with the aircraft that launched it?

texts:
From Wikipedia:

  It also incorporates a datalink to guide the missile to a point where
  its active radar turns on and makes terminal intercept of the target.
  An inertial reference unit and micro-computer system makes the missile
  less dependent upon the fire-control system of the aircraft.

What is the nature of this "datalink"? What is it called, what protocol does it use?

How is this datalink secure?


texts: Will an axial compressor work with an ideal fluid?

texts:
Will an axial compressor, like the one described starting on page 275 of Mechanics and Thermodyanmics (PDF link), work if the flow was assumed to be ideal (i.e. incompressible and inviscid)?

Specifically, what mechanism will slow the flow down in the axial direction? It's my understanding that slowing the flow down is the job of the stators, but I fail to see how they accomplish this in the axial direction.  The author states on page 284 that the axial flow velocity through the compressor is made constant by design but never explains how that design is achieved and I'm curious if that design could still be achieved with an incompressible fluid. -Thanks in advance!


texts: Has a scheduled passenger flight ever stalled because of shifting cargo?

texts:
Has any scheduled commercial passenger - not cargo - flight ever experienced a stall due to cargo shifting, like the National Airlines Flight 102 did, back in 2013?

Please note I am specifically asking about scheduled airline flights with passengers on board, i.e. not cargo flights. No incidents involving tanks or other military equipment.


texts: Is a forward slip considered a "normal maneuver" under 91.175(c)(1)?

texts:
After an instrument approach in IMC, 91.175(c)(1) requires, among other things, that operations below the DH or MDA must allow for a "normal rate of descent using normal maneuvers."
Can someone point me to a regulation or a definition of what is a normal rate of descent and normal maneuvers under this regulation?
Specifically, my question is whether a forward slip is considered a normal maneuver for purposes of 91.175(c)(1)?


texts: What surface materials do airplanes use to reduce friction?

texts:
Full swimming body suits were banned from Olympic Games a few years ago because some materials have less friction than skin and contestants that could not afford gear to increase their performance were disadvantaged.
However, low friction materials could benefit many industries including aviation. Are there any special surface coatings either experimental or used by manufacturers to improve the aircraft performance and decrease drag?


texts: Does weight affect the fuel burn calculations in a light GA airplane?

texts:
When calculating fuel burn in say a Piper Archer, I usually just use the conservative estimate of 10GPH, but, does the weight of the aircraft affect my fuel burn?

Assuming I have full fuel and am taking off a max takeoff weight, will I still burn the same amount of fuel in 4 hours as I would if I took off with only myself in the plane and full fuel?


texts: In case of failure in the Electronic Flight Instrument System, how would they be transferred between each other?

texts: In EFIS, in case of failure in the PFD, where would be PFD shown? In case of failure in the ND, where it would be shown? In case the PFD & ND both fail, where would they be shown?


texts: What is the purpose of drag and anti drag wires?

texts: What are drag and anti drag wires,and how important are they to the performance and strength of the wings of an airplane?


texts: Would this "being paid while flying" scenario be considered "flying for compensation"?

texts:
The difference between a private and commercial pilot's license hinges on this critical ability to expressly receive pay for flying; a PPL is allowed to fly "in furtherance of a business" but cannot be paid to fly a plane, while a CPL can. That brings up an important question; in today's corporate world, there often isn't a strict "hours for pay" exchange; you get a salary, for which you perform the duties of the job (which do not necessarily mean being there 8 hours a day). So,  what's the difference between being paid while flying in furtherance of a business, and being paid for flying?

A simple example (I hope): I'm a salary man, and my workplace happens to abut a public air park in Dallas. A coworker of mine needs to get to Waco to have a short face-to-face meeting with a client (teleconferencing won't do), and my boss knows I'm a PPL and own a fairly speedy Cherokee 235 (cruising speed 135 mph). The forecast for tomorrow is perfect flying weather, so he proposes this deal; I commute to work in my plane tomorrow instead of driving. After morning coffee and e-mails, my coworker and I will head over to the air park and fly out from there to Waco in my plane and be picked up by the client. We'll have the meeting, be driven back to the airfield, and I'll fly us back to Dallas so he can drive home.

For this, I'll get paid for the workday as I normally would, no vacation or other leave time required to be used. My boss also suggests that I can expense my fuel costs and any landing fees, like I would be able to do with my gas and parking fees if I drove. My boss gets two people face-to-face with the client faster than if we drove, with less time off our normal duties than if we flew on a regional jet (and much cheaper), and I get paid to fly my plane without being explicitly hired to do so.

The questions:

Can I accept the deal at all, or will the fact that I'm technically being paid while flying be considered the same as being paid for flying even though no additional money specifically for my yoke time is changing hands?
What portion of my out-of-pocket costs can legally be expensed?

All my fuel and landing fees incurred between taking off from and landing back at my home field (which I otherwise would not have incurred)?
100% of costs from when I take off at the air park near work to when I return there (the portion of the flight in furtherance of the business)?
50% of "non-commuter" flight costs (gas to and from Waco and the landing fee there, but not the fees at the air park or gas to and from my home field)?
No expenses allowed (because that would be "compensation for flying")?

Would any of this change if I were an hourly employee doing this "on the clock" as opposed to being salaried?
Would any of the above answers change if my boss wanted me to rent a speedier plane (that I was rated for of course)? Would I be able to expense some or all of the rental?
I'll try not to make this an off-topic "legal advice" question: if I refused the deal because I thought it would violate the restrictions of my PPL on flying for pay, and I was summarily fired, should I be talking to a lawyer about a wrongful termination suit?


texts: Is there a specific relation between sideslip angle and yaw rate OR how sideslip angle depend on yaw rate?

texts: Since, yaw rate is controlled via rudder and sideslip angle can also be controlled by rudder, I want to know if there is any dependence of sideslip angle on yaw rate in fly by wire aircraft as I am working on the SAS design of a/c lateral/directional dynamics?


texts:
What is this door below the lavatory of this airplane?

Other aircraft have similar doors near the rear lavatory?


texts: How to convert a pressure height (ADS-B) to a geometric height?

texts:
As far as I know, ADS-B broadcast a pressure altitude, so I want convert it to geometric one. How is it possible?

e.g in MSG format: http://adsb-decode-guide.readthedocs.io/en/latest/position.html
which kind of altitude is there?


texts: How does a fighter jet perform good and quick maneuvers with such small wings?

texts: Fighter jets like the F-16, F-15, etc. have wings smaller than the length of the fuselage and can perform great maneuvers very quickly while an airliner with a long wingspan takes a lot of time to perform these kind of maneuvers. How does a short wingspan on a fighter jet perform such great maneuvers?


texts: What sort of sensors are used for sensing the positions of the control surfaces for the ECAM F/CTL page on Airbus aircraft?

texts:
During the pre-flight flight-controls-check how does the ECAM F/CTL page report on the actual positions of the control surfaces?

What sort of sensors are these? Is it a proximity sensor?

This is motivated by this related question about pre-flight flight-controls-check:
Testing control surfaces pre flight; what feedback does pilot recieve?


texts: How many landings per year are performed using the integrated standby instrument system?

texts:
Could you tell me how many landings are exclusively driven by Integrated Standby Instrument System or equivalent in the world per year ?

Same question with "partially" using instead of "exclusively".


texts: Bright exhaust in afterburner vs no visible (bright) exhaust when not in afterburner?

texts:
When a jet engine has its afterburner engaged, a bunch of fuel is dumped into the back of the engine for additional thrust.  This burning fuel causes the exhaust and inside the engine to glow brightly, which is quite visible even to the casual observer.  However, when the afterburner is not engaged, there is no visible light at all that I've seen coming from the engine's exhaust.  I would think that the fuel burning process of a normal jet would be visible out the back as well, just not as noticeable as afterburner exhaust, but that doesn't seem to be the case.

Is there visible light from the exhaust of a non-afterburner jet and I'm just not seeing it, or is the burning fuel inside the engine so much that it just doesn't get out.


texts: Why couldn't the A380 secure any orders for two straight years?

texts:
The double-decker aircraft has failed to win a single order from any new airline customer for two years now. Comparing its orders and sales with its biggest competitor, the B747 it had received 315 orders in its first 10 years, about 40 years back. Today though, the A380 has recieved 317 in its first 8 years, but it failed to receive even a single order in past two years.

  “It’s true the market hasn’t developed as much as we’d have liked,” Airbus Chief Executive Officer Fabrice Bregier said this month. “This plane was probably launched 10 years too early.” (Source)

Why couldn't the A380 sell as much as the B747, even though it has won many admirers in a shorter period of time. Also, a rough comparison shows A380 is worth its price, when compared to 747-8. But the 747-8 is still getting more orders than the A380.

Update : Iran Air has finally ordered some A380s in February 2016.


texts: Why are airliner underbellies generally painted differently?

texts: Some airlines, Delta in particular, have dark underbellies on their liveries. Is this only aesthetic or is there a purpose for it?


texts: I am no expert at the Development Assurance Process, but hypothetically speaking what Design Assurance Level (DAL) would a human pilot receive if they were classified as one (i.e. DAL A, B, C, D, E). It seems absurd to try and answer this question since the plane can't even leave the gate today without a pilot or pilots, but I am hoping to learn more about the DAL process thru any answers received.


texts:
This article states:

  An occurrence was reported where an Airbus A321 aeroplane encountered a blockage of two Angle Of Attack (AOA) probes during climb, leading to activation of the Alpha Protection (Alpha Prot) while the Mach number increased. The flight crew managed to regain full control and the flight landed uneventfully.

What is Alpha protection?
Is it part of another major system (like auto-pilot)?
What can it do?
How is it activated?


texts: Why does the 757 fuselage bend more on turbulence than those of other airplanes?

texts:
According to this discussion(2nd)(3rd) and this video there is more fuselage bending in turbulence on the Boeing 757 than on other Jets.

Why does the B757 fuselage bend more on turbulence?
What are the factors related into fuselage bending?
I always thought there is only fuselage bending during take-off and landing on tarmac.

Edit: Picture Zoomed, fuselage shows flexing.


texts: How many layers do the Boeing 787 cabin windows have and what might make them fail?

texts: I am interested to know how the Boeing 787 cabin windows are made. Specifically, how many layers do they have and what can make them crack in-flight?


texts: What vertical separation is required in a holding stack to avoid wake turbulence?

texts:
Sometimes in my free time I play Endless ATC, a game where one acts as the approach and departure controller. In the game (as in real life) the controller is forced to put planes in a holding stack, separated vertically by 1000 feet.

Is this vertical separation - 1000 feet - enough on its own to prevent one plane's wake turbulence from affecting the plane immediately below? Or is it possible that I've accidentally had planes fly in each other's wake turbulence?

If so/if not, then what's the minimum vertical separation necessary to ensure one plane's wake turbulence doesn't affect the next plane in the holding stack?


texts: How should the VFR Cruising Altitudes (FAR 91.159) be applied over rising terrain?

texts:
Imagine flying at 4500' indicated altitude, 4500' AGL, heading 270, directly towards a steep mountain ridge that tops out at 4000 feet.  Imagine the mountain being almost like a flat wall.

When can I change altitudes to >4500' and still be in compliance with 91.159?  Do I have to wait until I get close to the ridge when I'll be under "3,000 feet above the surface"?  Can I interpret "above the surface" in a more liberal way?

  § 91.159 VFR cruising altitude or flight level.

  Except while holding in a holding pattern of 2 minutes or less, or while turning, each person operating an aircraft under VFR in level cruising flight more than 3,000 feet above the surface shall maintain the appropriate altitude or flight level prescribed below, unless otherwise authorized by ATC:

  (a) When operating below 18,000 feet MSL and -

  (1) On a magnetic course of zero degrees through 179 degrees, any odd thousand foot MSL altitude 500 feet (such as 3,500, 5,500, or 7,500); or

  (2) On a magnetic course of 180 degrees through 359 degrees, any even thousand foot MSL altitude 500 feet (such as 4,500, 6,500, or 8,500).

  (b) When operating above 18,000 feet MSL, maintain the altitude or flight level assigned by ATC.


texts: For electric aircraft, is MTOW = Empty weight + Maximum payload?

texts:
Electric aircrafts and most drones have simple powertrains, and their weight does not vary along the flight. After reviewing this thread I assume that:

MTOW = Empty weight (batteries incl) + max payload ?

I have reviewed some drone specs, and sometimes the numbers match, others don´t. Am I missing something?


texts:
Steering a seaplane on water appears to be a little more 'interesting' than steering a land aircraft, at least according to the FAA Practical Test Standards for single-engine seaplanes (ASES), which requires the pilot to:

  [use] flight controls, flaps, doors, water rudder, and power correctly
  so as to follow the desired course while sailing.

So how does it all work? Why/when/how do you use doors and flaps to steer? Are the water rudders connected to the pedals (like brakes on a land aircraft) or is there a separate steering control? What about braking: is there any, or do you just drift gradually to a stop?


texts: What is the technique or procedure to disable/disengage the MCAS on Boeing 737 Max 8 & 9 Aircraft?

texts:
What is the technique or procedure to disable the MCAS and manually fly the Boeing 737 MAX 8/9 Aircraft?
To clarify my question, what I'm asking is can the pilot disengage the MCAS and if so, how do they do that? Is it just flipping a switch or popping a breaker, or is it a complicated set of procedures?
UPDATE: The answer to this question explains how to disable/disengage the MCAS from pitching the nose down.
UPDATE: This video is the most concise answer to my question that I have found. It shows a crew in a full motion simulator like the Boeing 737 Max 8 that crashed in Ethiopia, then it shows the proper technique to disengage the MCAS and manually trim up in the same scenario.


texts: How to do a Rapid Descent in a jet with inoperative spoilers?

texts:
So, let us assume you are in a simulator for your favorite jet plane, and the instructor gives you a LOFT (Line-Oriented Flight Training) scenario that goes as follows:

A normal takeoff and climb to cruise altitude, and perhaps thirty minutes of normal cruise flight
The non-recoverable loss of speedbrake (flight spoiler) functionality due to a mechanical jam, or some other malfunction such as the loss of all SECs in a FBW Airbus.
Another 30 minutes of time to deal with the first malfunction: run the checklists, plan and initiate a diversion if needed.
You lose normal cabin pressure for some reason, and have to conduct a rapid descent to get back to 10,000' and complete your diversion.

How do you execute the descent, considering that the rapid descent procedures for most jets rely on using the speedbrakes to achieve a high descent rate without overspeeding the aircraft?  To use the 737 QRH checklist for Emergency Descent as an example:

  EMERGENCY DESCENT . . . . . . . . . . . . . . . . . . . . . .Announce

  The captain will advise the cabin crew, on the PA system,
  of impending rapid descent. The first officer will advise
  ATC and obtain the area altimeter setting.

  ENGINE START switches . . . . . . . . . . . . . . . . . . . . . . . . CONT

  THRUST levers . . . . . . . . . . . . . . . . . . . . . . . . . . . . CLOSE

  Reduce thrust to minimum or as needed for anti-ice.

  SPEED BRAKE . . . . . . . . . . . . . . . . . . . . . . . . . FLIGHT DETENT

  DESCENT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Initiate

  Target speed . . . . . . . . . . . . . . . . . . . . . . . . . . . Mmo/Vmo

  If structural integrity is in doubt, limit speed as much as
  possible and avoid high maneuvering loads.

  Level-off altitude . . . . . . . . . . . . . . . . . . . Lowest safe altitude
                                            or 10,000 feet, whichever is higher


texts: Are NPRMs published in the Federal Register?

texts:
Are FAA NPRMs (Notices of Proposed Rulemaking) published in the Federal Register?
I am currently researching the history of some airspace rule changes from the early 1990's, and am trying to figure out whether searching the Federal Register will turn up NPRMs, or only the resulting Final Rules.
For instance a "Terminal Airspace Reconfiguration NPRM", which is referenced on page 38963 of the Federal Register Volume 57 # 167 (Thursday August 27 1992).


texts: If all control surfaces were disabled, could a passenger plane be controlled by distribution of the passengers?

texts:
Let's assume that a large military plane has its control surfaces disabled in combat. The engine(s) can still be controlled. There is a substantial number of ground forces being transported.

In theory could the plane be flown purely by distribution and redistribution of the weight of the passengers? Note these are military personnel and are used to acting on orders.


texts: Which organizations and individuals are invited for a review before the first flight of a new aircraft?

texts:
The first flight of a new aircraft is a major aviation milestone for the company and the industry.  What departments or organizations (within a parent organization), and what individuals, are invited to the pre-flight review of a First Flight of a new aircraft?

What kind of stake holders are invited?
How many Technical guys are invited?
Is there any regulation by FAA to include a particular parties?


texts: Can i get A&P course materials in .pdf format?

texts: I would be very grateful if you provide me any material about A&P basic course for mechanics.