Max Shutterspeed

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'?

Anthony Supplebottom

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

HeddW

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 .

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

Runon

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

HeliStudent

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?

grumpytroll

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

Gordy

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".........

Dennis Kenyon

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.

AAKEE

@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.

311kph

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

Savoia

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 !!

Aucky

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.

SilsoeSid

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.

[email protected]

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.

JohnDixson

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.

[email protected]

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

Anthony Supplebottom

Something very graceful about large helicopters doing rolls -

JohnDixson

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.

Dennis Kenyon

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

Dennis Kenyon

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.