Questions tagged [aircraft-physics]

Physics as they apply to aircraft, including aircraft motion, forces affecting an aircraft, and stability and control.

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2answers
139 views

What is the explanation of this airfoil phenomenon? Why the air from below the leading edge's tip deflected up?

I have difficulties to understand this air phenomenon, why the air from below the leading edge's tip (from below the horizontal line) is deflected up and not just follow the bottom wing's surface? ...
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0answers
82 views

Does the angular momentum of a jet engine affect aircraft performance?

I am interested, do jet engines have angular momentum? And how does such momentum affect airplane stability?
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41 views

How do I calculate the center of lift?

See my other question here for the background context. Consider this simple plane. I have applied the 4 basic forces: lift, drag, weight, and thrust. My question is, where, precisely, do I apply the ...
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1answer
66 views

How much force is produced by control surfaces?

Context: For some context, I'm a game developer and I'm building a flight sim game. My goal is to have realistic -- not arcade -- physics. The game is in Unity. Unity handles the actual application ...
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1answer
172 views

How do I obtain the max endurance altitude?

There are excellent explanations of the physics that determine maximum endurance speed here, here, and here. I was thinking of aircraft that have to be "on station" without an indicated altitude and ...
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1answer
103 views

What is an example of a quantitative analysis for the lift using Newtonian mechanics?

There are several different ways of explaining how an airplane generates lift. The simpler qualitative explanation uses Newtonian mechanics (the third law is invoked to explain how the wing pushes air ...
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1answer
36 views

How to calculate on ground aircraft yaw rate knowing the longitudinal speed and inferred yaw angle

Please consider the following scenario: a generic aircraft is on-ground taxing at 50 feet per second (~15.25 m/s, ~29.5 knots) The pilot inferred 20 degrees of yaw How can I calculate the yaw rate ...
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2answers
195 views

What is the “compression ratio” of air hitting the nose?

Sorry but I don't know how to accurately phrase this question. I want to know how much compression results from air hitting the nose of an aircraft. I'm interested in the traditional airliners (Mach ...
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3answers
161 views

What are accurate flight simulation models called? Is there a standard model?

I'm risking a question that might be "opinion based", but I hope it will not be seen as that. This question is touched upon in the following questions: What are the differences between PC and ...
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1answer
214 views

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

There have been a couple of questions on this site about the efficiency and propulsive power of turbine engines (here, here, here). In a high bypass turbofan engine, what are the losses in the ...
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1answer
75 views

At what angle-of-attack (sideslip angle) would a symmetrical vertical fin stop “helping” a deflected rudder produce sideforce? [duplicate]

For rudder deflection angles of 5, 10, 20, 30, and 45 degrees, at what (negative) angle-of-attack does a fin-rudder combination (including dorsal fin if present) create exactly the same amount of ...
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1answer
181 views

Would all these three things have the exact same effect on the flight duration of a glider?

Consider a glider trimmed to fly at some given angle-of-attack, gliding in smooth air (no thermal convection, ridge lift, wave lift, etc.). If air density is somehow kept exactly constant in all ...
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1answer
51 views

What does a higher pitching moment mean? (ie -0.095 vs -0.0022)

I've found that as the angle of attack increases, the moment becomes more negative. I wanted to know what does that negative value say about the characteristics of the airfoil, and what is its ...
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36 views

Two aircraft with same air speed, blank angle, but different mass, are the radius of turn the same? [duplicate]

Two aircraft with same airspeed, blank angle, but different mass, are the radius of turn the same?
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0answers
114 views

Why don't single propeller planes rotate around the horizontal axis? [duplicate]

According to Newton 3rd law, every action has reaction force in the opposite direction. That's how spaceship can move in space. That's why helicopter needs a second propeller in the back to prevent ...
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1answer
179 views

Could a rotor head wing be plausible?

Could a helicopter support a detachable wing with no controls on top of the rotor head in place of a radar dome? Could the rotor head be made to support more weight? Would it be more fuel efficient at ...
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2answers
4k views

How possible is a successful landing just with 1 wing?

Having in mind this famous F-15 incident : Would this be possible with any other fighter-jet? Or was there something really specific to F-15's design that allowed this ? Would this be possible at all ...
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3answers
261 views

Will the plane take off? [duplicate]

First, I was unsure where to ask, here on on Physics SE. Second, I have a strong feeling it might have been asked already somewhere but I didn't find it - so if it was, please link as a duplicate. ...
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2answers
135 views

With power off, is it possible to maintain constant altitude for some period of time, until the stall speed is reached?

With power off, is it possible to maintain constant altitude for some period of time, until the 1-G stall speed is reached, i.e. until the stall angle-of-attack is reached? Implicit in the question ...
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3answers
218 views

Is it better to have the engines center or apart on a plane?

Are there any advantages or disadvantages to having the engines closer or farther to the center of the plane? How is the ideal engine spacing determined length or span wise for performance? Related: ...
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1answer
148 views

How did Airbus A380 overcome corrosion issue in which aluminium wiring used? [duplicate]

The corrosion of aluminium is generally recognized to be a major problem. What new technologies or technics might be used in aluminium wiring to get away from the corrosion issue?.
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1answer
412 views

Using aluminium busbar/cables in an aircraft instead of copper [duplicate]

I have just found out Airbus uses aluminium wiring in the A380 to save weight. However, I didn't see anything about whether all the wiring is aluminium, or if copper wiring is also used. What is the ...
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2answers
658 views

At what altitude does a wing become useless? [duplicate]

At what speed or altitude does an aircraft become more efficient as a rocket then a plane using thrust vectoring instead of the wings to steer? At what altitude did the flight control surfaces of the ...
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4answers
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How can lift be less than thrust that is less than weight? [duplicate]

Physics in schools teaches two contradictory and mutually exclusive things: That the upward lift force on an airplane in flight equal its weight (Lift = Weight = Mass x Gravity). This is based on ...
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2answers
118 views

May turn rate indicators (and turn coordinators) be calibrated to be accurate at all airspeeds, or only for one?

2 related questions: may a turn rate indicator be calibrated to be accurate at all airspeeds, or only for one? Likewise for a turn "coordinator". The meaning of "accurate" intended in this question ...
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4answers
207 views

What is the formula for the bank angle required for a turn in line-abreast formation?

Imagine we have a line-abreast formation of aircraft, with differing airspeeds, turning around a central pivot point, like points on the radius of a phonograph record, with an equal amount time per ...
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3answers
125 views

Does pumping fuel to each wingtip affect roll trim in a stabilized turn?

If an aircraft is stabilized in a constant-bank, constant rate turn with no sideslip, and then we pump 200 gallons of fuel from a fuselage tank to a tank on the tip of each wing, without changing the ...
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3answers
343 views

Why are Vertical tails generally tapered?

I'm just intrigued to know why the vertical tail of a majority of aircraft is tapered? Is it due to aerodynamics, structural design or due to some instrumentation or multiple other reasons?
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788 views

Would this be a dangerous impeller to use for a drone?

I am considering using a 3D printer to make unconventional impellers for a custom-made drone that I am planning to build. I am concerned that these plastic impellers may explode if their motors' RPMs ...
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1answer
65 views

Do aircraft performance figures include corrections for areas with especially strong or weak gravity?

The strength of gravity at the Earth's surface is not constant, but varies from place to place by as much as a few percent: (Image by NASA.) As a result, an identically-loaded aircraft weighs less ...
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5answers
363 views

How much energy is “wasted” in an aeroplane's descent?

In descent, an aircraft must lose both potential energy (in order to get down to the ground) and kinetic energy (in order to land at a safe speed). Weight and drag can take care of that. An unpowered ...
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3answers
248 views

What does the “nose-high” product of inertia represent?

I am reading this slide: Source: http://www.stengel.mycpanel.princeton.edu/MAE331Lecture10.pdf Is Izx always considered small and we can assume it is 0, as many texts assume? I need to make this ...
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3answers
209 views

What is the derivative of the angle of attack?

Suppose a flying missile's velocity vector has components $u, v, w$, as illustrated below. From my knowledge of flight dynamics, the angle of attack is $$\alpha = \arctan \left(\frac{w}{u}\right)$$ ...
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4answers
185 views

What is the effect of the Load Factor on wing Structures?

I am quite confused with the definition of Load factor and how it applies to the wing structures of an aircraft. For example, you have an Aircraft being subjected to a Load Factor of 2 and whose ...
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1answer
98 views

does a semi sphere have more drag in comparison to a flat plane with equal surface area?

What the title says, some things to know is that these aren't solid shapes, think of a bowl and a sheet of wood.
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3answers
496 views

Why did Air France flight 447 fail to recover from the stall? [duplicate]

I have read the wikipedia entry about the accident but I don't understand why did the stall happen and why the plane couldn't recover from the stall. Correct me if I am wrong but I would think a ...
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1answer
149 views

How energy efficient is an aircraft take off?

How much work is generally done by an aircraft (e.g. B737NG) in order to reach V_rotate, and how does this compare to the energy content of the fuel that is used?
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1answer
328 views

How fast do four Tire-Propellers have to rotate to lift 2000 lbs? [closed]

I just saw this come out, Goodyear's Tire-Propeller Concept – a combination tire that can also act as propeller (well, more like a ducted fan I guess). There's a neat video that goes with it, ...
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4answers
260 views

Why does elevator still raise and lower the nose when the aircraft is steeply banked?

In a steep turn, the aircraft is basically sideways. However, when executing a steep turn, one still raises and lowers the nose of the aircraft by using the elevator. Intuitively, it seems to be ...
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3answers
3k views

How does a single engine tail wheel landing gear airplane turn when it is on the ground?

Say Cessna 140 as in this video, look like no additional device to make it turnable when it on the ground. It is a single engine and a tail wheel landing gear. Then, how does it turn?
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2answers
94 views

Which one is more effective produce power of this two turbine's location?

Consider we have the exactly same turbine which is possible to be mounted to the tail (left picture) and to the wing (right picture) as picture below. Which one will produce more power to the airplane?...
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2answers
217 views

How does pulling back provide better steering during rollout for light GA planes?

I had requested clarification on an answer to the question, How do I keep a C172 straight on the centerline during landing/rollout? I did not comprehend how pulling back after touch down provides ...
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3answers
7k views

How does the F-35B not flip over during transition?

As the engine nozzle rotates, the lift-fan cannot. Wouldn't this imbalance of moments around the center of gravity result in the F-35 pitching up onto its back? As can be seen at 5:14 in this video: ...
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2answers
232 views

Which one needs longer runway of an airplane between take off and landing for a constant weight?

Consider we have an airplane that the weight will be constant when take off and landing (in fact will be no such common airplane right now as the fuel will be less due to engine consumption. But in an ...
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1answer
224 views

Why are all-moving horizontal stabilizers common but all-moving rudders rare on fighters?

According to Wikipedia Stabilators were developed to achieve adequate pitch control in supersonic flight, and are almost universal on modern military combat aircraft. All non-delta-winged ...
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1answer
172 views

What is the most effective of propeller's rotation in a two-propeller engine airplane?

Consider two-propeller airplane as picture below (picture 1 (the above) and picture 2 (the below)). Which one is the most effective configuration to produce thrust power, stability, structural design, ...
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2answers
567 views

If a twin-engine airplane's propellers both rotate in the same direction, do they still produce a left-turning tendency?

If an airplane with two propellers has both propellers with the same rotation direction (say, both the propellers rotate counter-clockwise as seen from nose to the tail), will be the four left-...
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4answers
496 views

What is the maximum angle between an airplane and runway centerline when touching down at a crab angle in a crosswind landing?

What is the maximum angle between the airplane's heading to the runway when an airplane is being landing sideway due to crosswind?
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5answers
6k views

People in a rollercoaster or falling elevator feel the rapid descent, so why don't pilots in the cockpit?

Judging from the CVR transcript, the AF447 pilots didn't realize for most of the plunge that they were stalled and rapidly losing altitude. Why don't pilots in the cockpit get the same sensation of ...
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3answers
277 views

How does the power requirement change when weight and speed change?

Suppose I have an airplane with a certain weight M, which uses a certain amount of power P, to fly at a certain speed V. If I use the same airplane, but quadruple the weight (4xM) and double the ...