270 degree roll

[smithy2003]

Quick question. Is there a name for the rather pleasing 270 degree roll into a high G turn during an air display?
Thanks in advance

[Intruder]

In some applications, a "tuck-under". Dunno if it's universally accepted...

[Localiser]

It's called a 'Derry Turn' I believe.

[pithblot]

It's a Derry Turn, named after the first pilot to break the speed of sound in England, De Havilland test pilot John Derry. I don't know if Mr Derry "invented" the Derry Turn, but he certainly popularised it. And you are right, it is very a pleasing manoeuvre.

John Derry was killed with his observer and 29 spectators in the 1952 Farnborough Air show tragedy (http://news.bbc.co.uk/onthisday/hi/witness/september/6/newsid_4219000/4219540.stm).

[DaveReidUK]

A Derry Turn starts when the aircraft is already in a steeply banked turn. By rolling in the direction of the low wing and passing through the inverted, the aircraft ends up in an equally steeply banked turn in the opposite direction.

From start to finish, the roll attitude change is nearer to 180° than 270°.

[Background Noise]

Yes, classically a Derry turn is a reversal of an established turn by rolling underneath, rather than rolling through upright.

What you describe is a Canadian Break - starting from wings level, instead of rolling in the direction of turn to (almost) 90 degrees of bank, the ac rolls through 270 degrees in the opposite to the desired direction of turn (or break).

[pithblot]

Background Noise and DaveReidUK

You are quite right gents, I stand corrected.

pithblot

[FAStoat]

Yes there was such a thing as a 270 degree roll,but usually this was a 3 out of 4 point roll,which is then held at the 270 degree point.Providing the entry speed is fine at this stage,a one and a half knife edge flick is then initiated,finishing on the opposite knife edge,which is then followed by the remaining quarter point roll back to the horizontal straight and level.This should be completed from straight and level flight.Back in the 70s Rothmans Solo man,usually Iain Weston,used to perform this frequently,as the Pitts has the power to weight to achieve it without losing the necessary entry speed after holding the third point in knife edge.Bucker Jungmeisters were capable of doing this as well because of exceptional control surfaces,with only 160 HP available.Another Jungmeister owner and pilot,the late James Gilbert showed me how to do this with relevant entry speeds at Redhill back in 73.The only point of achieving a 270 degree roll would be to end up on knife edge,either to then follow with the flick or proceed down the crowd line in knife edge flight for the purpose of showing the Aircraft to the public/photographers.A Derry turn has nothing to do with this,as explained by the posters above.Hope this is useful!!??

[Background Noise]

Well not quite. Have a look at this video from about 7:15. This is at the end of the display, the aircraft rolls 270 degrees left to enter a right hand turn into a right hand circuit to land.

https://www.youtube.com/watch?v=6anllAGw6ZM

[Intruder]

In Blue Angels parlance, that's a "tuckunder break". Much more impressive when done from formation...

[Background Noise]

Ah, see what you mean - slightly different terms either side of the pond then.

Blue Angels (https://www.youtube.com/watch?v=Qb6BgqNMviM)

..and a line drawing explanation: Tuck Under Roll Turn - Advanced Aerobatics - Jet Fighter School II by Richard G. Sheffield (http://www.flightsimbooks.com/jfs2/chapter3-13.php)

[smithy2003]

Jeez,sorry guys. Work means am only just now looking at this....

Thanks for the replies. You have described exactly what i meant.


https://www.youtube.com/watch?v=bJuYh4eVCs8