An AAC QHI did as many loops in a minute as possible in a Gazelle for a Matthew Kelly TV prog back in the 80s ISTR.

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There is an early video (1950's ??) of a Sikorsky (S-52 I think) doing a complete loop above the factory property .

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I’m pretty sure that Sid S@#£&3r spent a fair proportion of his gazelle time upside down.

Please forgive an ignorant question – I know very little of the subtleties of rotary flying – but if it's possible to do a 1G barrel roll in a fixed-wing, isn't it possible to do a 1G barrel roll in a helicopter without stressing either the airframe or the moving parts?

Marginally more gutsy than my Basingstoke Carnival display in 1973!

Mog

It isn't possible to do a 1 g barrel roll in a FW - it's a myth that is perpetuated, and defies the basic laws of physics and motion!

You keep positive g throughout the manoeuvre and acceleration towards the centre of the manoeuvre but it goes more and less than 1g but not into negative figures (unless you cock it up):)

You can "attempt" a 1g barrel roll though - just won't turn out what you expected!

Aero's in a helicopter can be done "within limits" - the issue is Joe Pilot doesn't know what they are as the manufacturer or certification authority does not publish them.

Test pilots are called "test pilots" for a reason and they come in different flavours - Production and Experimental. Production Test are pretty much average Joe and Experimental Test live a bit closer to God than most!

Helicopters mostly if any do not have a large enough thrust margin to create high g loadings. They will just mush or wash off speed.

It's the other bits that most people don't think about that are the issue that maybe cannot keep up with what the aircraft "could do".

i.e. precession loads on the TR, feedback to the MR PCL's, Low or prolonged -ve g on lube, fuel and HYD systems and the list goes on.

For example - everybody knows about HYD "jack stall" in an AS350. Why is it that way? It is to give you a built in warning that you are approaching the feedback limits of the PCL's on the MR.

Dual HYD models have a LIMIT light as the warning as they will not "stall". What happens if you go past the "LIMIT"?. You probably will start bending and breaking stuff.

Operating outside the approved envelope is the territory of ETP's. Joe Pilot doing this stuff proves what exactly? You get away with it once, you get away with twice you get away with it...................................?

And don’t forget that those ETP’s operate dedicated , instrumented aircraft of which the critical parts can be monitored either in the cockpit or in a telemetry room full of engineers who can call “STOP” at any time during those tests…

Looks like 1G to me.

Bell 407 at an airshow in South Africa, circa 2004.

Bell permanently grounded the aircraft (and all components)

All you can tell from the Hoover video is that is positive G, but not how much. It is theoretically possible to maintain a minimum of 1G during the maneuver, but then you will have a maximum of well over 1G towards the end, as you will be in a rapid descent that needs to be arrested.

Exactly. You can’t start and end with 1 g! Newton 2

212man and others - thanks for your helpful comments.

Informative:


The school.

I thought this was a “Professional” Pilots rumour network?

Looping and rolling helicopters have no place or requirement when flying professionally. So any wannabes reading the !!!!e posted in this thread………just don’t!11!

All the warnings about rotor and airframe stress forgetting that if the positive g disappears all the fuel, oil and other juices necessary to keep the cab healthy end up in the wrong place.

Moronic Darwinian selection in action.

DB - do you know what the g limits for your helicopter are?

Is there a specific warning in the RFM about negative g? (other than for Robbies)

You can get negative g in turbulence - does all the fuel and oil disappear then?

No-one has suggested anyone tries this, it was a question worth asking and answering.

Most manuals will prohibit aerobatic maneuvers, they don't go into much more detail, it's not what civvie helicopters were designed to do.
It also looks quite dull, even with Chuck whatsisname in the 105, it's the wrong tool for that job.
If "pulling g" is the objective, choosing rotorcraft will prove disappointing.

I agree Bell_ringer, but DB getting on his high horse about a thread where no-one has suggested just going out and trying such manoeuvres seems rather OTT.

My point to DB was that less than 1g in a helicopter or even negative g doesn't lead to the instant mechanical failure he implied - you can get to negative g without aerobatic manoeuvres as you know.