Questions tagged [flight-dynamics]
Flight dynamics is the study of the physics driving the performance, stability, and control of aircraft. It is concerned with how forces acting on the aircraft influence its speed, altitude and attitude with respect to time.
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Why does this site allow misleading answers to remain, and stay at the top of the stack? [migrated]
In searching for some relevant photos for a lecture I am writing, I came across a question "Does lift equal weight in a climb?". The first answer, with most upvotes, is not only very ...
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Climbing turn with constant bank -- how to compute final attitude, from initial attitude and degrees of rotation about pitch axis? (Specific example)
(Note: highly related, but different: How to compute final aircraft attitude, if we know starting attitude and degrees of rotation around each axis? (Specific example))
I'm flying due north (000 ...
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How to compute final aircraft attitude, if we know starting attitude and degrees of rotation around each axis? (Specific example)
I'm flying due north (000 degrees heading), with bank angle of 0 degrees and a pitch attitude of 0 degrees.
I roll the airplane 30 degrees to the right, rotating only around the aircraft's roll axis (...
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Would twin-engine airplanes be safer (in case of engine failure) if had minimal dihedral?
In the specific context of the sudden failure of one engine, would twin-engine airplanes (with wing-mounted engines) be safer if designed with minimal dihedral, so that aerodynamic coupling between ...
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Moment required for disk tilt Cierva Autogyro?
The first prototypes of the Cierva autogyro used a disk tilt mechanism rahter than cyclic pitch by means of a swashplate to achieve roll and pitch (DOI: 10.13140/RG.2.2.19168.94729).
Let's first ...
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Am I slipping or am I skidding?
I'm in a shallow left bank, maybe 15 degrees. Right rudder pedal is all the way to the floor. Flight path is curving toward the right. Ball is far to the left corner of the glass tube. Yaw string1, ...
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What causes a jet airliner (with a yaw damper) to roll toward the "weaker" engine during an asymmetrical thrust condition?
Please help me better understand what causes a jet airliner (such as the Boeing 737-500) to roll toward the "weaker" engine when power is reduced on one side.
Such as in the situations ...
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Why should the leading edge of the horizontal tail be lower than the trailing edge? [duplicate]
As mentioned in this answer: https://drones.stackexchange.com/a/2564/5088
The leading edge of the tail should be lower than its trailing edge, providing some "down force" in flight.
I am ...
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What causes a slip/skid turn? [duplicate]
Is the rate of turn being too low/high for a given bank angle the cause of slip/skid turn? Or is it yawing too much inside/outside turn causing an imbalance in centripetal/fugal force and thus the ...
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Causes of yaw in slip/skid turn [closed]
Why does the plane yaw when the rate of turn is not suitable to bank angle in a turn? In a slipping/skidding turn, there is an imbalance of centripetal/ centrifugal force. How does that cause a yaw?
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Why does increasing speed in a turn not change load factor?
From what I've read, load factor (n) is the forces of lift (F) divided by weight (W), so the equation would be n=F/W. In a question about a constant bank angle turn, an increase in airspeed will ...
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Would an S-92 / CH-148 (or any helicopter) be able to land successfully after rolling over and eating someone with its main rotor in flight?
In the SCP Foundation story "Over/",1 the protagonist and his fiancée get kidnapped by some terrorists looking for information, who eventually throw the two of them out of a CH-148 (with ...
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Does the reduced aerodynamic damping at higher altitudes affect the Vno (maneuvering speed) of an airplane?
Since reduced aerodynamic damping at higher altitudes reduces the needed control input for maneuvers, is this just about the required force to move the controls or also about the speed of the ...
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Control surfaces on radio-control models of airliners
Do large RC airliners like the huge Emirates RC A380 still need all the same control surfaces that a real A380 has I,e leading edge slats? If not why is this the case.
Many thanks for your time in ...
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what is acceleration of gravity in free fall situation with air drag? [closed]
consider a ballistic missile in reentry trajectory with initial velocity of 1000 m/s. as missile enters the atmosphere, air drag decelereting its velocity so missile's acceleration becomes negative. ...
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Which Provides a Faster Turn - A Horizontal Turn or a Vertical Loop?
I am starting to research this question with respect to WWII aircraft - specifically the FM2 Wildcat, which was considered an excellent dogfighter.
To approximate an "apples to apples" ...
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What is the direction of the centrifugal force of a hinged helicopter blade?
In helicopter dynamics the flapping angle and corresponding equation is a well known concept. Suppose now that an hinge is added to the rotor, as with gyrocopters and that there is an aerodynamic ...
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Without wind, would a plane go straight if the pilot let go of the controls?
If you let go of the steering wheel of a (properly maintained) car, it will typically go in a straight or nearly straight line. Would a powered airplane in no-wind conditions do the same thing?
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Terminology: is the "normal acceleration" (nz) considered to be 1 G, or 0, when an aircraft is at rest on the ground with fuselage horizontal?
This is meant to be a question about terminology, not a request for an explanation of the underlying physics at play.
When an airplane is in constant-speed straight-and-level upright flight with the ...
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Can an ionized airflow be controlled magnetically?
I am thinking about the possibility of replacing the control surfaces of an aircraft with thrust vectoring. The most straightforward form of that would be mechanically adaptable nozzles which ...
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Aircraft load factor and body normal acceleration
A load factor is defined as "the ratio of the lift of an aircraft to its weight", i.e., N = Lift/Weight.
Normal acceleration (nz) is defined as the component of the linear acceleration of an ...
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Why is more angle of bank (AOB) at the best gliding speed giving less altitude loss?
Reading the manual for the T6b (turboprop aircraft single engine), it says different altitude losses during a 360 degree turn, holding 125 kts (the best glide for range speed), power is either dead, ...
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Do airliners reduce their angle of attack to maintain lift = weight as fuel burns off during cruise?
For an aircraft to remain in level flight, it must generate lift force that is exactly equivalent to its weight. However, modern airliners lose a lot of weight when they are in cruise flight in the ...
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General Rule for Calculating Center of Gravity of any Aircraft Configuration
I'm looking for method(s) to determine the CG of any fixed wing aircraft for it to be reasonably stable. I only know for conventional aircraft, placing the CG between 1/4th and 1/3rd of MAC behind MAC ...
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At what angle to the ground track does wind become favorable to lower fuel consumption?
We can all agree, flying from point A to B, a headwind will increase fuel consumption, and a tail wind will reduce it. The "jet stream" inspires these types of thoughts.
Quartering headwind,...
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Does does turning into the wind increase airspeed and/or climb rate?
At 5:24 to 6:10 in the video linked below, Kelsey appears to be claiming that turning into the wind tends to create 1) an increase in airspeed and 2) and an increase in climb rate. Are either of ...
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What does deploying landing flaps do to the (L/D)max and minimum drag speed of an airplane?
I thought that deploying flaps will increase both the drag and lift, thus increasing L/D ratio? But do they increase proportionately? And how exactly does that correlate with the increase/decrease of ...
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Change of absolute ceiling with weight
Let's say an aircraft has an abs ceiling of some value at the start of its cruise and then it consumes some percentage of its fuel during cruise. How will this change the new abs ceiling at the end of ...
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Aircraft pitch and AOA change during a coordinated turn maneuver
Let us say I am flying a constant airspeed turn while maintaining my altitude, when I enter into the turn, lift has to be increased and since airspeed remains constant, the AOA has to be increased to ...
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Can an encapsulated airfoil generate enough lift to lift the capsule?
Can an airfoil generate enough lift, if it is contained in an enclosed space, to lift the enclosed space? Assume that there would be sufficient airflow over the foil to generate lift if it was not in ...
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If i have equal lift and drag, do they cancel each other out?
I am working on a throw glider and was wondering, How much lift would be too much lift, as in it causes the glider to stall (maybe thrust that causes this, but still). also, if I create a body that ...
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Body angle rate and body angular velocity
Are these terms used interchangeably to mean the same things?
I'm aware of the conversion between body rates (often, $[p, q, r])$ and Euler rates (commonly, [$\dot\phi, \dot\theta, \dot\psi])$. This ...
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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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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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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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Given roll angle and constant velocity, calculate new position
I'm simulating an aircraft in Simulink and then using a controller to make it follow a reference path. My control inputs are elevator, aileron and rudder angles and the outputs of the state space are ...
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What "designs" the dihedral angle in modern airliners?
Is this an accurate description of the design process for modern jet airliners?
If not, why not? What other factors come into play in determining the choice of dihedral angle?
Designer starts by ...
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How to calculate lateral velocity of a turning aircraft
An aircraft in a 45 degree banked turn has a horizontal lift force vector equal to the weight of the aircraft. Although the Coefficient of Drag is much larger for the aircraft profile, it seems there ...
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What was the tactical purpose of the unusual flight control system that allowed the Northrop YA-9 to generate sideforce without banking?
What was the tactical purpose of the unusual flight control system that allowed the Northrop YA-9 to generate sideforce without banking? (And, how was the system controlled by the pilot?)
(Image is ...
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Viable to slip onto the center line?
One of the constant problems of aviation is drawing onto the center line on final. Either due to a bad rollout or due to crosswinds a pilot often finds that the aircraft is not on the center line for ...
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Why is this plane struggling to gain altitude?
Here in this video, you can see an airplane trying hard to gain altitude (happens at 1 min 17 secs, original video):
Plane Gets Struck By Lightning
I am skeptical. Does it actually happen, or is the ...
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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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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 ...
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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 <...
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Why is the ball no longer centred in a multi-engine airplane with inoperable engine?
I'm currently working on my PPL, and whilst trying to understand fully how the turn coordinator works, I got down a rabbit hole that makes me question my understanding, and that I can't dig myself out ...
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What means when center of pressure is out of physical dimension of wing?
Center of pressure(CoP) is point where total force vector acting at. If you hold wing at this point, wing will not rotate(moment=0). Example hanging point at hanglider.
I see at some diagrams for very ...
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How the AOA, Pitch and FPA are changing during a flight maneuver
For a steady state flight, there is a equation that FPA + AOA = Pitch, but how these three variables are correlated during a flight maneuver like currently I am in a leveling flight and then I want to ...
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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/...
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Can I just differentiate my Euler rates to get the angular rates?
There is this matrix:
$${W_{\eta}}=\begin{bmatrix}
-\sin(\theta) & 0 & 1 \\
\cos(\theta) \sin(\phi) & \cos(\phi) & 0 \\
\cos(\theta) \cos(\phi) & -\sin(\phi) & 0
\end{bmatrix}$...
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In a banked turn, why does the center of gravity, rather than the center of lift, follow the path of a circular arc?
I'm a post-solo student pilot who sometimes gets hung up on fundamental points of aerodynamics.
"As long as the aircraft is banked, the side force is a constant, unopposed force on the aircraft. ...
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