R44 loop - latest Robbie bashing thread
 

Not really a loop (close enough)but seriously stupid... :eek: :eek: :eek:

balls of steel

R44 numpty
 

I guess if he'd had an accident/incident it would be RHCs fault

No neg G there what's the problem. :8

R44 loop - latest Robbie bashing thread
 

No loop there either!

I guess some guys never listen or learn
 

R44 Pilots Operating Handbook - Section 2 - Limitations: Aerobatic flight is prohibited!

Wasn't there a 407 in SA that did a very expensive loop on camera a couple of years ago!? Bell made them change parts worth around $ 1 mil after that one.

Might have balls of steel but there is **** all between his ears.

Don't really see the problem. He's doing somewhat of a "wingover", no loop or even close to a loop for that matter. The camera angel fools you a little :)

I'm quite sure that is a model helicopter and by the sound it just might be jet turbine powered.

BTW it is perfectly easy to loop a model helicopter with a teetering head rotor system. You just need lots of speed before entry otherwise you dont make it around before getting a mast bump - which isnt serious as the masts are usually solid steel and they wont break very easily.

I cant think of a real helicopter with the required grunt.

oow

A number of "real" helicopters have the "grunt" to pull a loop. The first recorded on film was 1949, an S-52
Others since

Licensed to Loop: America's Only Aerobatic Copter Pilot | Autopia | Wired.com

For freshman flyers .. please be sure to read the word "model" in the above statement as attempting a loop or roll with an underslung system in a full size aircraft and it's likely to be the last thing you do!

If you must loop .. then this is how to do it:

...and this is how not !

...and if anyone wishes to copy the actions of Dennis 'The Maestro' Kenyon's antics, as seen on Savoia's link, just remember even Maestro's cock it all up eventually!!!

Someone mention mast bumping?

The Lynx was back-flipping, not looping.

The s-58s did it too!

Rotor separation what...?:ugh:

No neg G but probably 10Gs at the end. Good luck to whoever flies that one

Cock-up
 

Yes, the Salt Lake City accident surely qualifies as a master cock-up, and just goes to prove that even after that particular 'wing-over' manoeuvre had been publicly performed around two and a half thousand times, a small drop in self discipline and peripheral awareness bites back hard.

SLC airfield ... 5,800 ft ASL, temperature +96 degrees F ... So just to say please don't try this at home without some guidance from a qualified DAE. Best wishes to all loopers. Dennis K.

Loops
 

Oh ... and to keep the record straight, the video clip embedded by Savoia was the Enstrom version of a Loop performed at North Weald. The accident Salt Lake City Sikorsky 300C manoeuvre was a 'nil power wing-over.' For the uninformed - not a lot of difference perhaps. DRK

"Don't f***ing loop them unless it says in the flight manual you can" would have to be the definitive answer on the subject, I'd have thought!

Is it me? In the original R44 vid at the beginning of this thread, did the aircraft enter scene from the right, but then finish the maneuver heading away from the camera? Intentional?
And in Robinson's eyes, what is the legal definition of 'aerobatic'?

Anything more than a 20° turn in a Robinson is considered aerobatic !! :E

This was at the WHC in Russia back in August wasn't it?

He did quite a few of these, two on board i seem to recall and some being right over our heads whilst enjoying a post competition beer :8.

Maybe not a full loop but looked as good as from the ground...

Dennis Kenyon !!!! -
Thank you for being active on this forum - a lot of freshmen flyers like myself appreciate your knowledge and advice.

I second that as I have read a lot about Dennis Kenyon on the forum.

I had wanted to ask Mr Kenyon - when looping a helicopter do you have to put the collective control down or does is remain in flight mode?

ahem
 

Pretending to be Mr Kenyon's attorney: "Don't answer that!"

Dennis:

Actually SLC is at 4227' and your display was at West Desert Airfield in Fairfield about 30 miles south at 4902', although the terrain is higher all around you out there.

I'm with grumpytroll, "Don't answer that".........

Heli Student
 

To hell with the legals ... I cannot advise on what other display pilots do to produce a loop, but at the highest point (and minimum 'G') of the standard loop manoeuvre I fly, the collective lever is in its LOWEST position. Indeed when practicing in a piston helicopter, I have actually 'split' the rotor and engine speed needles, ie an inverted autorotation. At the 1978 Farnborough exhibition, the MBB 105 pilot, Zigggy Hoffman told me he did the same. Once again... "Don't try this at home without guidance from an experienced display pilot. Dennis K.

@Dennis: One important thing(quite obvious, but anyhow): In a heli with 'normally' hinged blades, ie fully articulated hinge, the low pitch and 'inverted' auto shouldn't be a problem itself. But if it was an two bladed heli with seesaw hinge it would be very, very dangerous.

so, at the highest point, when upside down , LOWEST position means collective is in pilots armpit :E

Lol, how thoroughly refreshing!

I heard about this prolonged inverted manoeuvre in the 105 (I thought it was Karl Zimmerman but it may well have been one of the other German Air Force drivers) but never actually saw it.

Ciao Denissimo !!

Interesting, is that to maintain the rounded shape of the loop (or else gravity and more pitch together would make it more peaked once inverted)? Logic would say to me to raise collective to ensure maintaining disc loading, but then i'm picturing this in the R44 above which wouldn't take well to an unloaded disc.

DKI think some would consider Dennis' post to be 'guidance from an experienced display pilot'. Lets just hope the legals aren't required by the family of someone following that guidance.

IIRC - the 105s used for the more extreme manoeuvres (esp inverted flight) had the rigging adjusted so that at min collective position, they were actually able to get a small amount of negative pitch.

You can fly a loop without lowering the lever at the top but, as Aucky suggested, it won't be a nice, FW-style circular loop. The Lynx loop does have an element of lowering the lever over the top but not as far as MPOG and definitely not sub-min pitch - IIRC the engine oil system just will not cope well with negative G and the white-metal bearings at the input stage don't like being without lubrication.

Although Dennis lowers the lever at the top, I suspect he retains a smooth aft cyclic pull so as not to unload the head.

The real danger of looping - as one of the previous videos shows - is letting the nose drop in the second half of the manoeuvre, the speed will increase very rapidly and you will eat up your recovery height very, very quickly!
Fortunately, unless you actively push the cyclic forward too much, flapback helps with the recovery.

CH-53/S-67
 

Same pilot ( Byron Graham ) did both of these. Dive to about 170 with about 70%Q. Fix collective, pull to about 2.5 G, then, approaching vertical and with speed decreasing, increase collective to maxQ ( 100% in 53-111% in 67 ), go over the top, then back to about 70%Q for the pullout.

That's one way of ensuring you retain positive G and disc loading over the top;)

Something very graceful about large helicopters doing rolls -

53/67
 

Anthony, the 53 movies were flown by Byron Graham and USMC Major ( at that time as I recall ) Robert Guay. One day Byron mentioned that they tried very hard to do Cuban Eights as well, but were not able to get the maneuver to come out on the entry heading, despite a lot of tries in attempting to eliminate the gyroscopically induced coupling. No films exist of these efforts, but I imagine they would be eye-opening, in a sense.

Ref 311kph
 

I think the term 'lowest' in this context is ... 'relative to the lateral and/or longitudinal axis.' Dennis K

For S
 

And for Savoia ... the other German pilot you were thinking of is Herman Fuchs who came first at the 1986 'freestyle' WHC held at Cranfield using the factory standard 105. MBB seemed to have stopped their sponsored display flying a while back. Then Red Bull took over the mantle. The 105 type is probably the most 'agile' helicopter produced to this date, certainly in the hands of the likes of the marvellous Germans ... Charlie Zimmerman, Herman Fuchs and Ziggy Hoffman. I've always felt so honored to fly with them in competition. Dennis K.