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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How does the accelerometer calculate component turn angles? (yaw, pitch) One first then the other? Or both simultaneously? [closed]
This question is not specific to a particular engineering architecture. But I am hoping that most aircraft are designed in the same way.
When the aircraft yaws and pitches at the same time, which ...
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References for lift and drag coeficient formula/values
I'm looking for references for values/formula for lift and drag coenficients. In this paper https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=6244461 it is said that
$C_L(α)$ and $C_D(α)$ ...
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What is a "rapid changes in gravitational force"
I've been reading an article on the BBC Website about the 21/May/2024 incident on Singapore Airlines. According to this article:
"The rapid changes in G over the 4.6 seconds duration resulted in ...
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In a straight and level flight if thrust is equal to drag how is aircraft moving forward?
If two forces are equal and acting in opposite direction should not the object remain stationary.
Is there an excess thrust which actually pushes the aircraft forward ?
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How do you compute the net lift force location?
There are a lot of formula that give an approximate solution to the lift and drag forces associated with certain wing configurations.
What I'm curious about is how do you find where the net force is ...
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What are all the ways that wind velocity can affect a paraglider/ canopy before it touches the ground?
Let's assume that a "perfect" humanoid robot flying a ram air parafoil (paraglider or canopy) performs some maneuver for landing exactly the same way multiple times.
The only difference ...
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Doubt in the Coriolis component of the net force acting on the aircraft
I dig a little and got to know that the force equation in 6DOF are nothing but a mathematical depiction of the fact that for a translating & Rotating body in 3D,The net force is the Translational ...
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Why is the wave drag of a straight wing less than that of a swept back wing?
According to NASA's claims, when the swept back wing is inside the shock cone and the shock is not attached to the leading edge of the wing(subsonic leading edge), the wave drag of the swept wing is ...
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Turbocharged vs Turboprop cruise altitudes
I know that both turbocharged & turboprop engines offer better performance above 10,000 feet than normally aspirated piston aircraft. My question is to what degree do their optimal cruise ...
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How to calculate fuel burn rate in Model BK117 helicopter
I am confused which parameters we are use, I have fuel quantity, fuel flow, fuel weight and speed etc is there so how to using and which parameters using the Endurance time calculate in helicopter
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Hexacopter Vn diagram/ flight envelope/ operational envelope
I am currently intern at a company. They are making agriculture hexacopter, now there is a confusion that does the hexacopter or multicopter have a V n diagram if yes how to make one what's the ...
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What causes the secondary effect of rudder, and which direction does it act?
I understand that rudder deflection causes several things to happen. Primarily the aircraft yaws, and for a positive (trailing edge left) rudder deflection there will be a positive side force ...
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How does the horizontal component of lift when flying at a bank angle cause the aircraft to follow a circular path?
I understand that when the aircraft is put into some bank angle, the lift vector now acts at that angle instead of directly against gravity, so we can pitch the aircraft up to increase AoA to increase ...
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Thrust needed to overcome parasite drag that increases with speed
Can anyone explain this passage from page 11-5 of the PHAK: “ For example, if an aircraft in a steady flight condition at 100 knots is then accelerated to 200 knots, the parasite drag becomes four ...
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Yawing during turns
This is a question about aeronautics. Does an airplane yaw while it is turning?
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Entry to back-side of power curve
When entering slow flight, when do we enter the back side of the power curve? Is it when we reduce the throttle or when the airspeed decreases to just above 5 knots from the stall speed?
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Why does the turn tighten in a Spiral Dive as it progresses? Even without applying any elevator control?
Why does the turn keeps getting tighter as the spiral dive develops?
Use of elevator control makes sense as it would increase the horizontal lift vector inside the turn. But even without any elevator ...
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Taxiing with a crosswind
Let us say we have a right quartering headwind, we should “fly into the wind” so yoke to the right then that our right aileron will deflect up and left aileron down. How does this avoid the chances of ...
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If in a coordinated turn, the horizontal lift vector is equal to the Centrifugal force. Then how is the aircraft still turning?
Image source
How does the Aircraft continue to turn when the both the Horizontal component of lift and the centrifugal force are equal?
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What are the effects of whiteout (snow) and brownout (sand/dust) on helos?
Is there any other effect besides low visibility?
Both seem to show very similar conditions.
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What differences would a helicopter designed to withstand many negative Gs have compared with a normal one?
There are a few helicopters that are able to take negative G's, and to this day only one can actually perform aerobatics (ie. Chuck Aaron's BO-105). The BO 105 is a rigid rotor helicopter that has ...
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Why is a flat turn less efficient than a coordinated turn?
How I understand a flat (rudder-only) turn:
AOA between relative wind and the fuselage of the airplane causes a sideslip in the direction of yaw.
Vertical stabilizer weathervanes into the relative ...
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What is the theoretical justification for "proportional navigation (PN)" guidance law?
In missile guidance theory, one of the fundamental guidance algorithms is the so-called "Proportional navigation", which directs a constant-speed missile into a collision course with the ...
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What would happen to the aircraft and its control surfaces immediately after the loss of all hydraulics?
In cases like the DHL shoot-down in 2003 or the Sioux City crash, both aircraft lost all of their hydraulics because of a catastrophic failure of aircraft structure.
What would happen if the aircraft ...
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Does AOA become 0 after the aircraft flies in a particular attitude for sometime as the relative airflow has changed and how does it affect Stall AOA?
As AOA is the angle between relative airflow and Chord Line. Then after you increase the angle of attack and fly at that angle of attack for some amount of time and the relative airflow changes ...
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why lift coefficient decreases at supersonic flow?
In Anderson's performance book, he wrote that the higher the speed, the greater the pressure difference between two points, and as a result, the lift coefficient is greater.
But when we reach the ...
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Could you use the flaps to recover from a flat spin
If the plane is in a flat spin, what would happen if you put the flaps down to cause the backward turning wing to be pushed down, and the forward turning wing up, to tip it out of the spin.
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Maximise Range Vs Pitching Down while flying a Glider in a Downward Air Mass
While flying a glider, if I encounter a downward moving air mass (i.e. sink) while on final, should I fly to maximise range (best lift to drag ratio) or should I pitch downward in order to exit the ...
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What can cause an unstable phugoid mode?
For clarity, I am wondering about how aircraft design can lead to the phugoid poles becoming complex with a positive real part, so an oscillation with increasing amplitudes.
My understanding of the ...
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Can the use of wide-chord supercritical airfoil blades in a helicopter with coaxial counter-rotating rotors solve retreating blade stall?
The problem with retreating blade stall is that it limits the VNE and the overall top speed of helicopters. Retreating blade stall is basically the tip of the retreating blade having too much AoA at a ...