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

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2answers
74 views

Is drag higher when flying in a crosswind?

Is this true that during a flight with a crosswind the drag increases due to the fact that the relative wind blows at a certain angle to the aircraft's nose but not precisely in the opposite direction ...
2
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5answers
192 views

Are we changing the angle of attack by changing the pitch of an aircraft?

For example: if I pitch the airplane up, but also increase power and am able to maintain the same speed, then no, the AoA hasn’t changed, although it may have varied in the transition between one ...
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0answers
39 views

How to compute actuator torque requirement for Variable pitch mechanism??

Suggest me any reference to compute the torque requirement for actuator/motor to control the pitch angle of propeller (Variable Pitch Propeller). Thanks in advance Arun Ravindran
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3answers
910 views

Does the pressure at the static ports drop as the aircraft's speed increases?

This answer by Tyler Durden explains what static ports are and how they work: The "static ports" allow air into the instrument to provide the input for the air pressure on the side of the aircraft. ...
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1answer
36 views

How to calculate the induced drag coefficient?

In an exercice of Flight mechanic, I have to compute the drag coefficient at zero lift: $C_{D0}$.We saw in class two ways to find it : $$ C_{D0} = \frac{\pi AR e}{4E_{max}^2} $$ With $AR$ the aspect ...
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5answers
84 views

Is there any effect that contributes to roll stability even in the absence of sideslip?

Is there any physical dynamic-- involving high wing placement, "pendulum" effect of CG far below wing, or anything else-- that contributes to roll stability in a way that is NOT dependent upon the ...
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6answers
166 views

Which way (if at all) do the ailerons need to be deflected in a full-rudder sideslip in a Cessna 152 or 172?

Do you typically have to maintain an aileron deflection in a constant-heading full-rudder sideslip in a Cessna 152 or 172? If so, in which direction? And why -- what is the source of the roll torque ...
1
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0answers
49 views

Induced drag - inverse proportion between induced drag and parasitic drag [duplicate]

I recently learned that the slower an aircraft is traveling, the higher the induced drag and the lower the parasitic drag. The parasitic drag is lower because the particles have less force against the ...
4
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1answer
114 views

How do you know the maximum load a control surface can withstand?

source This is a separate strength testing (load testing) of the elevator of an airplane, how was the load determined? How did the engineers determine the maximum elevator load?
2
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4answers
232 views

Does the required torque to spin a propeller increase with RPM?

I‘ve currently been experimenting with different propellers: 12x12 prop, 16x12 prop (both two blades) and a 22x14 (6 blades) prop. They were propelled by a 2.4 kW electric motor with 260 kV on a 6S/...
2
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4answers
177 views

Why is best angle/rate of climb indicated in airspeed?

I understand the difference between best angle of climb $V_{x}$ and best rate of climb $V_{y}$. When I take off I would aim to maintain one speed or another depending on what I want. But I don't ...
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4answers
187 views

Do swept back wings affect the moment of inertia of an aircraft enough to be relevant for the roll response?

I have studied that swept back wings help in delaying the shock waves formed on the wing, but also to my understanding I feel swept back wings reduce the moment of inertia (like for example a ...
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1answer
57 views

How do the vortices affect the flow of the horizontal stabilizer upon leaving the wing?

Other than the downwash effect, what other factors that affect the flow to the horizontal stabilizer? such as Dynamic Pressure? Air Flow Disturbance?
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2answers
83 views

Where can I find the best site to learn aircraft design on a small scale? [closed]

I am undergraduate student still trying to figure out a lot about Aerodynamics and aircraft design. I am learning how to design rc planes. So the thing I know the weight of my plane which is between ...
0
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1answer
85 views

How to determine the maximum servo torque required for a nose gear?

It's pretty much it. I know how to calculate the friction force on the nose gear for a three-point landing condition using the method set forth in ...
1
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2answers
193 views

What is the average aerodynamic load on a control surface of a commuter-sized airplane?

I'm doing a study about aircraft hydraulic pump sizing. In order to do that, I need to know the size of a flight control actuator, then determine the maximum flow and pressure that the actuator needs. ...
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0answers
129 views

How to calculate the shear force, and the bending and torsion moments on a wing?

I want to calculate the loads (shear force, bending and torsion moments). Assuming I have the force distribution along all the surfaces of the aircraft, my starting point is to consider the wing (and ...
3
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5answers
239 views

How do thrust reversers in high-bypass turbofan engines counteract initial thrust?

I've been searching the internet for awhile and haven't really come across a good answer for this question. So: I have a basic understanding of the principles of flight (thrust, lift, drag, etc). But ...
3
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2answers
713 views

What forces act on an airplane's door from the outside in cruise?

The inside cabin pressure from what I understand is pressurized to the values found at 6000-8000 feet high (11.34 psi at 7000 feet), at which point we can find the amount of force can be found acting ...
-6
votes
4answers
326 views

In which direction will an aircraft drift after taking off in a crosswind?

Assuming the pilot applies the appropriate crosswind flight controls (see below) during takeoff and rotation, and releases those flight controls after the aircraft leaves the ground, in what direction ...
1
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0answers
45 views

Single Engine operation on Twin Engine aircraft [duplicate]

I recently came across ETOPS and I wanted to know: How does a twin-engined aircraft balance out the lack of thrust on one side in the event that one of the engines is non operational? Any ...
-2
votes
2answers
342 views

What is the difference between centripetal and centrifugal force?

In a homework problem I was asked: In a balanced banked turn an increase in angle of attack will :? Answers are : 1/ reduce indused drag. 2/ increase centripetal force . 3/ increase centrifugal ...
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0answers
48 views

Could a airship be built using vacuum as the lighter-than-air “material”? [duplicate]

Could an airship be built that uses instead of a very light gas a vacuum to keep it floating? Or would the materials needed to keep its volume even without the pressure from the inside always be ...
1
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2answers
171 views

Is it possible to build a honeycombed vacuum balloon? [closed]

Is it possible to build a vacuum balloon with a near perfect void that can lift heavy objects and doesn't collapse and buckle under the atmosphere? I expect perhaps a honeycombed or lorimerlite ...
1
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2answers
170 views

Does angle of rotation during takeoff affect the g-force?

(Original) When an airplane banks 60° during row, 2 g of force is induced. When an airplane pitches 60° during takeoff, is 2 g induced on the airplane? Is the angle of rotation during takeoff ...
6
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2answers
402 views

How does the fuselage handle the different loads?

I have been trying to find out how the loads experienced by a fuselage are transferred between structural members (bulkheads, formers, frame assemblies, skin, longerons, stringers). I understand that ...
0
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1answer
169 views

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

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?
7
votes
3answers
483 views

Best procedure to Turn around in Canyon, Turn radius as a function of velocity

I just heard a briefing on mountain flying, and it was stated that the first thing, or the most important thing to do in the event you are unfortunate enough to find yourself in a blind canyon with no ...
1
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2answers
321 views

What is the average g force experienced on takeoff for an ultralight?

How much g-force is made on an ultralight during take off if its upward velocity of 2m/s?And what's the average g force experienced during takeoff on an ultralight?
2
votes
1answer
248 views

What factors are included in the moment coefficient of a wing?

I am trying to make sure I correctly understand the moment coefficient. Both the lift and the drag coefficients vary with angle of attack and can be either positive, negative or zero. The moment ...
4
votes
1answer
129 views

How to handle the formula for computing net thrust of closely coupled engine systems for an engine with a nacelle that has non-circular dimensions?

I am working on a paper and I wish to use this equation for calculating the thrust of an engine in a nacelle: $$ Fn= \displaystyle \oint V_x\rho\vec V\cdot\vec n \ dA + \displaystyle \oint(P-P_{\infty}...
5
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2answers
406 views

Why is Reverse thrust more effective at higher airspeeds?

It might seem logical at first but why is reverse thrust actually more effective at higher airspeeds? If we assume that engine performance will not change during a 100 knot deceleration on landing ...
3
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4answers
342 views

What is the flight trajectory of a commercial airplane in regards to altitude v/s distance?

So, my friend and I got into an argument regarding the flight trajectory of a plane. He said that for half the journey the plane is ascending and for the rest, it is descending and hence making a ...
5
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2answers
784 views

What is the physics of crosswind landings for large airplanes?

This always confuses me from a physics perspective. Upon touchdown, what is the effect of the wind on a large airplane/airliner (Boeing 737 and above)? Below are three cases I put together to make it ...
0
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1answer
381 views

Why do zero gravity flights not stall? [duplicate]

Airbus' (A300 / A310) are being used by French companies (i.e. Novespace) that offer zero G flights. Now the airbus seems to risk a stall at a 40 degree angle of attack (i.e.Air France 447). In a ...
3
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0answers
395 views

What is the maximum weight on the main gear of a large aircraft at rotation and touchdown?

For a large aircraft like a B747 or A380, how much does the weight on the main gear increase when the nose gear is in the air? I mean, in these two cases: What is the maximum extra weight on the main ...
3
votes
2answers
350 views

How does a helicopter hover?

Technically, unless a helicopter's centre of gravity and centre of lift (centre of the rotor) are in perfect alignment, it would generate a pitching moment which would make it unstable. So, how does ...
21
votes
4answers
3k views

Can a barrel roll really be executed at a constant 1G?

I see this stated from time to time, for example in an answer to Can large airliners do aerobatics such as loops? A barrel roll is one thing; they can be performed at constant load factor of 1 G (...
5
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2answers
182 views

Does rolling affect the thrust of a propeller?

If a plane with a propeller, e.g., a Spitfire, does a constant barrel roll in the same direction as the propeller, will the plane travel faster as impractical?
5
votes
1answer
200 views

What are the missions of high-endurance aircraft?

What have been the missions of some notable high-endurance aircraft -- ones that can stay airborne for several days. Obviously, high-endurance missions have refueling, food, and human factors concerns ...
3
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0answers
144 views

Was the Wright Brothers' 1902 machine a working glider or just a kite?

Was the Wright Brothers' 1902 machine a working glider or just a kite? I spent the last days reading the letters and articles of Amos I. Root, the man who claimed he had seen Wilbur Wright flying his ...
3
votes
1answer
3k views

What is the 0-60mph time of an aircraft carrier catapult?

Tesla's new Roadster is giving a 0-60mph time of 1.9 seconds. Truly ludicrous acceleration. I was wondering how a fighter jet released from a steam catapult compares.
1
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1answer
61 views

What is the link OR difference between change in momentum & pressure difference?

I ask in regards to the the thrust formula, which includes change in momentum, as well as difference in pressure between inlet & outlet of the engine to calculate generated thrust; this implies ...
23
votes
3answers
4k views

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

This question and another more recent one got me thinking about this. Years ago on my MEII checkride the DPE showed me a technique for losing altitude on final when the aircraft was high. Typically, ...
14
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3answers
6k views

What's the use of so much torque on propellers?

(This question is closely related to this question) A typical Cessna 172 has a 180 hp engine, with a max. rotational velocity of 2700 RPM. Even small 1 hp electrical motors can achieve that RPM, and ...
5
votes
2answers
483 views

Is it possible to hear a sonic boom when the aircraft is exactly at Mach one?

Will an observer on the ground hear a sonic boom if a plane passes overhead at exactly the speed of sound? That is, the plane does not cross the sound barrier. The plane just hits Mach one - and ...
2
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3answers
497 views

Can one fly up side down while a glass of water keeps full due to g-forces?

If one makes a looping for example with a plane and the g-forces that the planes makes will keep the water in the glass, but if one is at the top of the loop is there still enough g-force to keep ...
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0answers
34 views

How could aerodynamicists reduce the intensity of the sonic boom? [duplicate]

My understanding of the sonic boom is that it is caused when shockwaves being emitted from an object travelling at Mach 1 or above compress and superimpose on each other because they cannot move out ...
12
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3answers
1k views

Why did the F-104 Starfighter have a T-tail?

The F-104 Starfighter was launched in 1954, nine years after WWII. It had short stubby wings and a T-tail. According to wiki, the short stubby wings caused inertia coupling and the T-tail reduced this....
14
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8answers
7k views

Does lift equal weight in a climb?

This subject keeps coming up in the discussions and questions such as this one, which asks if lift equals weight in level flight. Good answers there, pointing out that upwards force has many sources. ...