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PPRuNeUser0131
4th Aug 2020, 06:11
While rummaging through my old crash comics for the disposal thereof, I found a story on Aerobatics & structural limitations (issue 102/1978, pps 19-23).

It started “Several months ago the owner of a Cessna 177B became concerned about the structural integrity of his aircraft when he learned that it had been flown in aerobatic manoeuvres”.

Yes, I know a Cessna Cardinal and aerobatics; it just doesn’t gel. I thought a Cardinal was hard pressed to fly straight and level.

It went on, “the pilot who hired the aircraft said later the he believed that he complied with the flight manual, by limiting manoeuvres to spins and chandelles. But when he described the manoeuvres he had done, it was obvious that what he thought were chandelles were in fact, stall turns …”; later in stated “It was fortunate the pilot did not attempt a lazy eight, for when he was asked to describe this manoeuvre, he said it consisted of two consecutive loops with a half aileron roll on the down side of each loop”.

But over the page, the ASD had diagrams of certain manoeuvres, one of which was a vertical eight. I have never flown one but I doubt if I ever would in any light aircraft, it being described as “a manoeuvre in which the aircraft performs an upward loop followed by a half roll and a downward loop, with entry and exit at the same level and in the same direction”.

The diagram (if i can get it attached to this post) is much better in seeing what was involved. All I can say is, that the aircraft must have been seriously pushing Vne on the way down after the half roll.

Anyone do these regularly, successfully?

I realise it depends on the speed over the top, but going downwards twice, under gravity in a Cessna, no thanks!

djpil
4th Aug 2020, 10:03
Anyone do these regularly, successfully?It has been a while. Not regularly but successfully. In a Pitts.
Page 15 at https://www.casa.gov.au/files/1551pdf

Wizofoz
4th Aug 2020, 10:57
Used to do this in an Extra 300 but without the roll- 1/2 inside loop, full outside loop from inverted, 1/2 inside loop.

Great fun!

Capn Bloggs
4th Aug 2020, 13:37
I did a vertical 8 in an F-15 once... straight after liftoff, going up! Well, I was in the back seat watching... Great great fun! Beat that Wiz. :ok:

Wizofoz
4th Aug 2020, 22:17
I did a vertical 8 in an F-15 once... straight after liftoff, going up! Well, I was in the back seat watching... Great great fun! Beat that Wiz. :ok:

Well, I WAS going the remark that the fun was somewhat mitigated when I saw the fuel-flow . But then, I guess you weren't paying for the fuel!!

Capn Bloggs
4th Aug 2020, 23:54
Everything was free in those days...:E

FL235
6th Aug 2020, 00:55
The late (lamented). Neil Williams used to do an air show vertical eight in “Ballerina” Cosmic Wind when it belonged to the Tiger Club, on a c85 power. His description of the manouver was a classic. Remember, no radio so start on exact time. Run in power dive to 200+ , pull up at about 50ft, pulling 8G or so for a half loop, push thru from level into outside loop, about - 6G. Engine stops, no inverted fuel system. Level again, pull into half. Loop, restarting engine and positioning to finish in starting position and altitude.

Some of his displays were hair-raising. Lomcevac in a Stamp at about 400ft ?

Pearly White
6th Aug 2020, 05:19
The late (lamented). Neil Williams used to do an air show vertical eight in “Ballerina” Cosmic Wind when it belonged to the Tiger Club, on a c85 power. His description of the manouver was a classic. Remember, no radio so start on exact time. Run in power dive to 200+ , pull up at about 50ft, pulling 8G or so for a half loop, push thru from level into outside loop, about - 6G. Engine stops, no inverted fuel system. Level again, pull into half. Loop, restarting engine and positioning to finish in starting position and altitude.

Some of his displays were hair-raising. Lomcevac in a Stamp at about 400ft ?
The guy was unreal. I saw him do an aerobatic display in about 1970, in a Spitfire modified with a second seat, came in just over the treetops at Blackbushe at over 400kt, pulled straight up and just kept going until it disappeared. Very fast, very loud. Better than any of the jets that took part in the display. All those high jinks, and he lost his life in 1977 during a routine ferry flight of a Spanish-built Heinkell He111.

djpil
6th Aug 2020, 06:49
I also saw Neil Williams' displays in the mid-'70s and chatted to him a couple of times. Anything from a Pitts, Zlin, Provost, Spitfire etc, just marvellous. He was interested in coming to work in Australia, same place that I was at. A couple of his colleagues ended up coming. After I read his book Airborne I wasn't surprised to hear of his final accident.

Wizofoz
7th Aug 2020, 01:40
I also saw Neil Williams' displays in the mid-'70s and chatted to him a couple of times. Anything from a Pitts, Zlin, Provost, Spitfire etc, just marvellous. He was interested in coming to work in Australia, same place that I was at. A couple of his colleagues ended up coming. After I read his book Airborne I wasn't surprised to hear of his final accident.

Yeah, he did seem to consider things like load limits "Advisory"!!