Lealaust !

[Kingfisher]

Hva er det som foregår her. Noen form for testing?
Det ser i allefall noe underlig ut.

Stein

[jj]

For høy hastighet

[Soarer]

Test av VNE..
Velocity Never to Exeed..
Alle fly har en slik grense som blir satt av karer som ikke har det akkurat kjedelig på jobb.
Seilfly i særdeleshet.

Av og til flyr de vingene av flyet, og åpner hooden og hopper ut når en ser at testen er vellykket..
Husk å notere farta..

[jj]

Du finner dokumentasjonen om akkurat denne turen ved litt googling. Har lest det før, men lenge siden

[OAK]

Du finner dokumentasjonen om akkurat denne turen ved litt googling. Har lest det før, men lenge siden

Sakset fra DG sine websider:

this DG-300/17 is a Research Plane, in comparison to the factory DG-300 is it a plane on which the wingspan was increased from 15m to 17m. The additional wingspan was added towards the wing root.

The filmed flutter with limited amplitude only occurred with a high water ballast. The too large water tanks contained more water than the allowed amount. The flutter tendency with increasing amount of water was known based on flatter calculation and static flutter tests by the DLR Institut for Aero-elastic. During these tests a small reduction within a limited speed range was discovered.

The observed flutter oscillation during this experiment of the glider in actual flight gave us the opportunity, to prove the results of the theoretical methods used. Of course it goes without saying that such high risk flight tests could only be planned and carried out by highly experienced specialists of the DLR Braunschweig.

To obtain the airworthiness certificate the water ballast was reduced to such an amount that for the normal use of this plane, for research purposes within the DLR and at the yearly IDAflieg comparison glider performance program, such Flutter cannot occur.

The film shows the flutter occurring at an airspeed between 140 and 150 km/hr during which the anti-symmetric wing bending and rotation momentum of the aileron are involved. By fastening the controls a non-linear reaction occurs , which develops a flutter with limited amplitude. Because of this, an overload and breakup of the plane does not occur.

When the airspeed by pulling on the stick, without hindering the sidewards movements of the stick, is reduced, the flutter oscillations will stop, but only when an appreciably slower airspeed is reached. This speed is the actual flutter airspeed of the plane. Flutter will start, when this airspeed is exceeded and the right disturbance influences the plane at this point.

Please Note:
All planes having an airworthiness certificate have gone through extensive static oscillation tests and flutter calculations in addition to a flight test program during which they have been checked for critical flutter behavior. Within approved operation field and its limitations as shown in the flight handbook one can be assured that no aero-elastic instabilities/flutter will occur.