Questions tagged [aircraft-physics]

Physics as they apply to aircraft. Including aerodynamics, flight dynamics, stability and control, aircraft hydraulic and electric systems, engine thermodynamics.

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2 answers
164 views

RPM of wheels on touchdown

What is the average RPM of the wheels of commercial airplanes upon touchdown? I understand there is variability that comes with different wheel sizes, approach speed, etc. Just thinking of the average ...
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3 votes
2 answers
475 views

What fraction of fuel is consumed just for keeping a plane in the air?

In a typical airliner, what fraction of fuel/power/energy is used for providing lift and overcoming lift-related drag Do the density of the air and the speed through it influence this ratio or do they ...
0 votes
1 answer
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for a piston-prop aircraft, why "V max excess power" equals Vmd and "V max excess thrust" equals Vmp?

as what i read from books, on thrust-velocity and power-velocity curves for a piston-prop airplane V max excess power= Vmd V max excess thrust= Vmp these two values are just so clicking, and i ...
-1 votes
3 answers
482 views

Induced drag - where does it actually arise from?

Several explanations about induced drag exist. Even if these explanations are simple and appealing (and not necessarily correct) they lack any connection to how actually the concept of induced drag ...
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9 votes
2 answers
2k views

How much momentum is lost through the wheels when landing?

I am idly curious whether any significant proportion of a landing plane's momentum is lost through wheel braking vs. everything else like thrust reversers, aero drag, etc? If I have to pick a plane, ...
0 votes
2 answers
189 views

Can fighter jets drift on air, and if so what does it look like?

I saw a video of a jet "drifting" from the air. I don't know if it was the quality of the video or my lack of knowledge with maneuvers but it didn't really do much but just fly over but ...
9 votes
1 answer
1k views

How AeroVironment's Switchblades steer their flight?

I'm very intrigued with how AeroVironment Switchblades: SW-300, and SW-600, steer their flight. There are plenty of images and animations and to my observation, none of the Switchblades have ailerons, ...
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-1 votes
2 answers
276 views

Has there ever been a VTOL aircraft thruster that generated lift through the use of a drag force?

I have been recently thinking about a conceptual VTOL aircraft thruster that should generate lift through the use of a drag force and I am very curious to know if such a thruster has ever been built ...
1 vote
1 answer
62 views

When using momentum theory for estimating power needed to hover, is propulsive efficiency accounted for?

I am using momentum theory to estimate power needed for an eVTOL. I have read past papers where the results got from momentum theory was direcly use to estimate the power needed from the battery. How ...
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3 votes
1 answer
415 views

Could the Wright Flyer II takeoff without wind?

The Wright Flyer II could reach about 20 mph of airspeed on the track alone. The aircraft needed an airspeed of about 30 mph to make a proper takeoff (without hanging in ground effect). Before the ...
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0 votes
2 answers
171 views

Which one produces more lift?

I have come across this question on Twitter. I have found a similar question here. The aircraft isn't flying but just doing Cobra Maneuver. Since the direction of the lift is in the same direction and ...
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7 votes
6 answers
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What is the name of the effect that causes a plane in a dive to go up?

What's the name of the effect that causes the aircraft to automatically pull out of a dive and buffet up due to aerodynamic lift produced at high speeds?
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-3 votes
4 answers
246 views

How can ground speed be higher than airspeed? [duplicate]

I've heard that ground speed is higher than air speed when the plane is being pushed by wind wind. But how is this possible? Wouldn't your AirSpeed also increase since you're going faster?
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0 answers
71 views

Is there an equation for how fast air accelerates into lower-pressure regions?

I’m designing a propeller, and I want to plan the shape of the trailing edge of each blade such that (as much as reasonably possible) the pressure comes out as an “equal” line. Thus - I'm wondering ...
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2 votes
1 answer
183 views

Why do transport-category aircraft have hard tailwind limitations?

With most transport-category aircraft, even with a 5 km runway, gross weight close to ZFW, using maximum flaps for takeoff, performing an unpressurized, full-power takeoff, the maximum legal tailwind ...
-1 votes
2 answers
161 views

Is Vbg maximum Lift/Drag ratio, or is it really maximum Speed/Drag ratio?

A question about "minimum power" airspeed had me wondering, why not think of "maximum Lift/Drag ratio" as maximum Lift/Thrust ratio. Gliders would be included, as they use gravity ...
3 votes
1 answer
79 views

How to calculate the inaccuracy in the "standard" turn radius equation, for supersonic airspeeds

I learned to calculate the radius of a level turn (r) using the function $ r = \frac{V^2} {g . tan(bank angle)}$. V is true airspeed, g is the local gravity constant. But now I have seen in the ...
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3 votes
1 answer
156 views

Are Airbus A320 Cabin Door Exterior & Interior Levers Linked?

Was looking at this video on Airbus A320 Cabin door procedures and was wondering if the exterior door lever is mechanically linked to the interior lever? It seems as if the exterior lever will open ...
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0 votes
2 answers
79 views

How does the velocity of a turboprop engine relative to the airplane change when a plane is banking?

I saw this YouTube video recently: And in it, a turboprop engine propeller and gearbox comes out and slashes across the underbelly of the plane, crippling the aircraft....
1 vote
3 answers
352 views

Why does power go up with the cube of the airspeed?

If i have an airplane with over 100 kN of thrust, and i want to accelerate from a velocity at which drag force is 25kN to a velocity twice higher, is it possible that i wont be able to do this because ...
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0 votes
3 answers
172 views

Calculate Rudder Angle by Bank Angle [closed]

My question: Is rudder angle equal to bank angle? Or, does rudder angle has some relationship with ROT formula? Below is my steps trying to solve this question. Step 1: Found below graph from this ...
0 votes
3 answers
317 views

Calculate speed by turn angle and distance [closed]

I'm trying to combine two rate of turn formulas, which I found it online this and this. The first is ROT = 1091 * tan(bank angle) / speed in knots The second is <...
4 votes
1 answer
198 views

Can a jet-engine aircraft fly all the way to its service ceiling at its maximum takeoff weight? [closed]

I am trying to understand how high an aircraft can get to at its maximum takeoff weight (minus whatever fuel is consumed in getting to that altitude). Can it make it all the way to its service ceiling?...
5 votes
3 answers
762 views

Is it realistic that a plane reacts very quickly to rudder input as shown in a MSFS video?

Microsoft Flight Simulator is supposed to be a "simulator", so following the laws of physics. However, I'm looking at a gameplay video (at 2:17) and it shows a plane reacting really quickly ...
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0 votes
1 answer
167 views

Can a fixed pitch propeller be designed to act as both a propeller and a generator?

The angle of attack (AoA) plays a major role in designing a propeller for specific uses, such as if it is to be designed for aircraft propulsion the AoA must be high, while the AoA must be low if it ...
-1 votes
1 answer
135 views

What are the feasibility of making a spherical aircraft using Magnus/Coanda Effect? [closed]

Well, I'm quite ignorant in aerodynamics in general, but I couldn't find any aircraft that fits this description. And yes, I know that wouldn't be as efficient as a conventional aircraft, but I'm ...
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7 votes
2 answers
1k views

G Load during payload drop

Some days ago I saw the accident of the airtractor that, just after a drop, suffered a spar failure in both the wings. Luckily the pilot survived. If load factor in his simplest formula is: n=lift/...
6 votes
1 answer
168 views

What are the wake turbulence characteristics at ground level near landing aircraft?

I'm a structural engineer and I need to understand the additional forces that wake turbulence may cause on a building near a runway. I can determine the natural wind speed and associated forces on the ...
5 votes
2 answers
952 views

Can the energy dissipated in a power-off descent be calculated and expressed in horsepower?

If the weight in pounds of an aircraft is known along with its sink rate in feet per minute at best power-off glide conditions, can the horsepower being dissipated by drag as the plane descends via ...
0 votes
1 answer
536 views

How to calculate the takeoff speed for a hypothetical aircraft?

Given some basic information such as: aircraft weight wing load (including wingspan, and basically the whole wing configuration) airfoil profile coefficient of lift angle of attack Is it possible to ...
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3 votes
3 answers
285 views

Can you have a Hybrid Turboprop-Jet engine?

To start things off I am writing this to gain information for vehicles in a story, so I am more so looking for theoretical possibilities, unless there are real world examples. The background and my ...
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0 votes
2 answers
172 views

Can aileron control maintain track in a single engine failure on a twin?

Let us say I am flying a twin-engine aircraft and I got a engine failure during cruise, without any control on rudder and use the ailerons only, can I still maintain the target track or heading? Will ...
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2 votes
1 answer
225 views

Are the gyroscopic precession and P-factor of a pusher propeller in opposite directions?

according to this picture the P factor cuases airplane to yaw to the right but if pilot wants to pitch up , then p factor and gyroscopic precession acts on airplane at the same time but in opposite ...
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2 votes
0 answers
97 views

Streamline Curvature Theorem applied to Airfoils?

I am new to studying aerodynamics and taking up aeromodelling and am currently learning how lift is obtained in-depth. When studying the two common explanations as to how lift is generated by an ...
2 votes
1 answer
217 views

Do pusher propellers create the same yawing moment as puller propellers? [closed]

We know that the effect of P-factor on puller propellers is the yawing moment in the opposite direction. I mean if we had a load (thrust or lift) on the right side of propeller, then the airplane will ...
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10 votes
6 answers
6k views

Why do planes fly at a high angle of attack when flying slow?

I've noticed that when a plane does slow flight, the pilot increases the angle of attack (AOA). What is the purpose of this? F-18 - Slow Pass
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0 votes
3 answers
218 views

How does bypass air work?

As far as I’m aware, high-bypass engines have far higher fuel efficiency than low-bypass engines, and as a result the effective specific impulse of the engine is increased. What I’m trying to figure ...
16 votes
5 answers
3k views

Why is thrust inverse to speed in piston engines?

It is said that piston engines have constant power output, and thus their thrust is inverse to speed (e.g. here), while turbines have relatively constant thrust. I'm looking for an intuitive ...
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1 answer
88 views

If aircraft specific energy is a combination of kinetic and potential energy, why is altitude not a variable in the energy-maneuverability theory? [closed]

The Energy-Manueverability formula is $$ P_S = V \left( \frac{T - D}{W} \right) $$ with velocity $V$, thrust $T$, drag $D$ and weight $W$. $P_s$ represents specific energy, which is a combination of ...
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1 vote
2 answers
180 views

How to fly a quick return to origin after takeoff

If I want the shortest traffic pattern to play touch and go or I got a emergency right after liftoff but the engine is still working, I just want to get back to ground as soon as possible, what is the ...
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2 votes
5 answers
345 views

Relationship between hover power and climbing power

I've been told that, generally speaking, rotor efficiency increase with rotor diameter. This is because the thrust generated by a helicopter rotor equals the mass of air moved times the delta V of the ...
7 votes
2 answers
510 views

How much does the fuselage of an airplane contribute to yaw stabilization?

Obviously considering that (almost) every plane has a vertical stabilizer, probably not, but for a relatively long aircraft does the fuselage measurably contribute to the yaw stabilization relative to ...
3 votes
4 answers
1k views

What is maximum acceleration that can be achieved by afterburner in level flight?

I am wondering how a fighter jet (let's take F-22 for example) would compare to other vehicles in terms of acceleration while in flight. For cars and motorcycles, achieving 0-100 KPH in 2 seconds is ...
2 votes
4 answers
237 views

Which way to turn to return to runway for downwind landing-- into crosswind or with crosswind?

The scenario-- you are taking off with a significant headwind component but also a significant crosswind component. You experience a power loss (or perhaps a tow rope break in a glider). You judge ...
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5 votes
4 answers
476 views

Is the total upwards vertical force (lift included) greater than the weight in a steady climb?

Related to questions on forces in a climb: if any aircraft is climbing with a constant velocity, is the total upwards vertical force (lift included) greater than the weight?
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0 votes
0 answers
48 views

Does a fighter aircraft slow down when firing machine guns? [duplicate]

I imagine the recoil of a powerful machine gun or cannon would decelerate a plane significantly. Is this an issue?
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2 votes
2 answers
1k views

Center of Gravity and Center of Lift stability

I have recently been reading about the center of gravity and center of lift. On the German Wikipedia there are many different graphics about the relation between the center of gravity and the center ...
-2 votes
3 answers
267 views

Is lift less in a steeper descent than in a shallower descent, and if so, by how much?

Is lift less in a steeper descent than in a shallower descent, and if so, by how much? For example, if we change our ratio of horizontal distance travelled to vertical distance travelled (through the ...
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-6 votes
1 answer
147 views

Would mid-air refueling for an air-to-space vehicle that flies like a plane be a viable advantage if the tech was available? [closed]

Let's take the style of an F-22 Raptor (awesome!), build the fuselage, wings, etc to handle runway takeoff horizontally and then vertically (if needed) up to orbital space flight to reach the ISS in ...
3 votes
1 answer
132 views

How can one change the wingtip geometry to enhance the wingtip vortices?

I'm doing some research on enhancing wingtip vortices as part of my Honours project. After spending a fair bit of time in the literature and on this forum I have some models which should kick-start my ...

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