All Questions
Tagged with flight-dynamics stability
25
questions
2
votes
0
answers
90
views
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 ...
1
vote
0
answers
306
views
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 ...
- 11
0
votes
3
answers
172
views
Simultaneous yaw damping and sideslip control of aircraft with rudder?
Yaw damping is achieved by using the rudder to generate a yawing moment that opposes any yawing motion. Also, rudder is used to correct sideslip by applying a rudder input in the opposite direction of ...
- 165
9
votes
1
answer
227
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Did the dog-tooth notches in the wing of the F-8 Crusader really have anything to do with "yaw stability"?
What was the real function of the "dog-tooth" notches in the leading edge of the wing of the Vought F8U crusader?
Wikipedia says:1
Vought's design team... produced... a relatively ...
- 22.9k
4
votes
2
answers
305
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How does conical camber decrease roll due to sideslip?
I was reading Ray Whitford's Design for Air combat and came upon a passage that said that on the SR-71 conical camber "gives a useful reduction in the otherwise very high rolling moment due to ...
- 41
6
votes
6
answers
5k
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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?
- 7,097
2
votes
1
answer
293
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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 ...
- 467
7
votes
6
answers
3k
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Is a trimmed flight not always an unstable system?
As soon as I am flying in trimmed flight condition, my pitching moment around the center of gravity becomes zero. So my center of pressure has to be located in the center of gravity, so that there is ...
- 71
1
vote
2
answers
305
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What happens if an aircraft is only stable at higher angles of attack?
Does anybody know what will happen to an aircraft, if it is stable (in longitude) for let's say: -8° > angle of attack > 8° ?
So for angle of attack 4° the aircraft is not stable (centre of ...
- 71
4
votes
1
answer
1k
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What happens when the eigenvalues of the longitudinal A matrix in dynamic stability analysis, are NOT two sets of complex conjugate pairs?
The complex conjugate pairs of eigenvalues of the longitudinal A matrix characterize phugoid and short period dynamic responses, this information is well established.
My question is - what happens ...
- 435
4
votes
2
answers
891
views
How does an aircraft designer increase dynamic stability?
This question explains that an aircraft can be statically stable (it will seek to return to equilibrium) but dynamically unstable (the amplitude of the oscillations increase) if there isn't enough ...
- 3,353
19
votes
4
answers
10k
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What does it mean when an aircraft is statically stable but dynamically unstable?
I am reading this book: "Flight Stability and Automatic Control", second edition, Dr. Robert C. Nelson. In the chapter 2, page 42, the author wrote:
Note that the vehicle can be statically ...
- 990
1
vote
2
answers
601
views
What is the purpose of downthrust?
Many light general aviation aircraft-- and perhaps many other aircraft as well-- are designed with some of amount of downthrust in the engine mounting, relative to the centerline of the fuselage. ...
- 22.9k
1
vote
3
answers
1k
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How attitude, speed, and altitude vary when increasing pitch?
I have been struggling with the following question for a while, would greatly appreciate some help and explanation why.
Scenario:
I'm cruising in my Cessna- cruise attitude 2300 RPM trimmed for 95.
...
- 853
3
votes
3
answers
1k
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Why does a banked aircraft create sideslip?
Below is an excerpt from Raymer (Aircraft Design) where he explains the dihedral effect. He states that a banked aircraft (due to say a roll disturbance) will have a sideslip which leads to a ...
- 616