A380 take off - tail strike ?

[dushank]

I recieved the following prictures through email from once of my friends.

Is this a tail strike ?

if so, is there anybody know where exactly this has happend and when ?

http://img353.imageshack.us/img353/9519/vmua380017ko.jpg
http://img353.imageshack.us/img353/516/vmua380022yk.jpg
http://img99.imageshack.us/img99/1521/vmua380030qd.jpg
http://img356.imageshack.us/img356/9085/vmua380049qj.jpg

[blueloo]

Yes - part of the testing is for Unstick testing - Vmu (for geometry limited aircraft). I believe it is meant to demonstrate (amongst other reasons), the ability to fly the aircraft off theground should overroatation occur. In the testing they dont actually damage the aircraft - you can see there is a bit of wood or something to scrape the ground on.


I dont know how often substaitial scrapes occur in real life, the most notably of recent times was Singair I think?

Someone who knows more about testing can elaborate.

[SMOC]

These actually weren't the formal VMU tests, these tests were performed to confirm data for the optimum flap setting for takeoff. The odd thing was that they did actually strike the tail aft of the tail skid/bumper a couple of times which required some repair work.

SMOC

[Dani]

VMU (Minimum Unstick Speed) is the lowest speed, at which the aircraft still is able to take off. Because the speed is so low, the angle of attack (the "nose up") has to be higher, thus the tail is lower and touches the ground. Below VMU an aircraft is not able to take off, it would skid along the runway, the angle of attack is not big enough to produce enough lift to get airborn, above VMU the aircraft is able to take off without the tail touching the concrete (but tail strike could still occur due to overrotation).

Dani

[dushank]

Thanks guys for the replies ...

I found more details in this link

http://airbusa380.canalblog.com/

Actually the deail is in French. You could use the google language tool to translate the text.

[Volume]

"With regard to the take-off trials at minimum velocity in Istres (VMU tests), Jacques Rosay reports that on the first take-off the A380 had rotated further than expected and not just on the shock-mounted tail skid provided for this purpose, but had also unintentionally slid along the runway on the tail section behind it. Fortunately the tail had been protected at that point with a steel casing as a precaution, so that no damage occurred as a result of this tailstrike. But in this special case, the aircraft had behaved differently from what the simulator had led the team to expect.

Since then, according to Rosay, the test pilots have adopted a different rotation technique for VMU tests: they now raise the A380's nose from the runway in an accentuated way at a lower taxiing speed and then carefully reduce the distance between tail skid and runway with minimal elevator angles. The tail skid now only touches the ground very lightly and can withstand four VMU take-offs instead of the previous one before it has to be replaced. "


complete story can be read on the
FlugRevue (http://www.flug-revue.rotor.com/FRheft/FRHeft05/FRH0511/FR0511g.htm) homepage.

[Gingerbread Man]

Did concorde have that little wheely dealy in case of over rotation, or was it supposed to use it in normal circumstances? Just curious.

Ginge :p