Questions tagged [flutter]

A type of uncontrolled divergent oscillations in an aircraft's structure, typically encountered at excessively-high speeds or if the airframe's stiffness has been reduced by previous damage. Flutter is extremely dangerous, and can rapidly cause an aircraft to break apart in flight; it has caused many fatal accidents over the years.

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12
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2answers
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How was flutter mitigated in jets such as the F-15 and F-16?

As I understand it flutter was a serious problem for early jets, like the XF-104. Flutter can affect any of the extended members of an aircraft during high-speed flight, including the wings and the ...
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4answers
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How are aircraft wings protected against flutter - aerodynamic oscillations that can break bridges?

It's a well known fact bridges can break due to self-amplified oscillations creating excessive loads on their structure, by resonance (galop). It happens from time to time. The Tacoma-Narrows bridge ...
6
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1answer
2k views

Why can not two modes coincide perfectly for some cases in Flutter phenomena?

I have a question about flutter phenomena. As you know, flutter occurs when two modes (for example, first mode and second mode) coincide (that is, after a specific velocity, the frequencies of two ...
18
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2answers
8k views

What causes aileron and elevator flutter?

This video shows a Hawker jet with the wing fluttering up and down like it's about to break. What can cause flutter like that? Can it actually cause a wing or stabilizer failure? How can flutter be ...
8
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3answers
667 views

How can engine positioning affect flutter tendency?

I understand that moving the engines towards the wingtips would increase flutter tendency, but are there any other positioning options which could affect flutter? How about moving the engine ...
1
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2answers
471 views

Why was the Electra uniquely vulnerable to whirl-mode flutter?

The Lockheed L-188 Electra, notoriously, suffered from early problems with whirl-mode flutter, which caused two Electras to break apart in flight in 1959 and 1960, forcing an expensive redesign of the ...