PDA

View Full Version : R44 loop - latest Robbie bashing thread


Flyting
8th Jan 2013, 10:36
j8h8PWv4AVI

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

Hughes500
8th Jan 2013, 12:13
balls of steel

Bondu121
8th Jan 2013, 12:27
I guess if he'd had an accident/incident it would be RHCs fault

chopjock
8th Jan 2013, 12:45
No neg G there what's the problem. :8

Harry the Hun
8th Jan 2013, 12:56
No loop there either!

hammerhead70
8th Jan 2013, 14:14
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.

Chopper Doc
8th Jan 2013, 14:29
Might have balls of steel but there is **** all between his ears.

martvidar
8th Jan 2013, 14:36
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 :)

outofwhack
8th Jan 2013, 15:04
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

John R81
8th Jan 2013, 15:18
A number of "real" helicopters have the "grunt" to pull a loop. The first recorded on film was 1949, an S-52 Sikorsky S-52 First Helicopter Loop - 1949 - YouTube

Others since

Apache Helicopter does a loop the loop at Farnborough, 2004 - YouTube
Lynx helicopter performing loop at Red Bull Air Race - YouTube
Licensed to Loop: America's Only Aerobatic Copter Pilot | Autopia | Wired.com (http://www.wired.com/autopia/2011/06/red-bull-chuck-aaron/)

Savoia
8th Jan 2013, 20:06
BTW it is perfectly easy to loop a model helicopter with a teetering head rotor system.

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:

s3vRD2kiG3I

SilsoeSid
8th Jan 2013, 20:56
...and this is how not !

HELICOPTER LOOP THE LOOP CRASH IN BELARUS - YouTube

SilsoeSid
8th Jan 2013, 21:07
...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!!!

Dennis Kenyon's helicopter crash 6-13-08 - YouTube

SilsoeSid
8th Jan 2013, 21:17
Someone mention mast bumping?

Mast Bumping in Helicopters - US Army Training Film - YouTube

MightyGem
9th Jan 2013, 00:28
The Lynx was back-flipping, not looping.

sablatnic
9th Jan 2013, 10:08
The s-58s did it too!

the best helicopter aerobatic of this world - YouTube

Soave_Pilot
9th Jan 2013, 10:21
Rotor separation what...?:ugh:

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

Dennis Kenyon
9th Jan 2013, 13:54
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.

Dennis Kenyon
10th Jan 2013, 05:26
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

Arm out the window
10th Jan 2013, 08:08
"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!

Max Shutterspeed
10th Jan 2013, 10:47
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
10th Jan 2013, 10:53
Anything more than a 20° turn in a Robinson is considered aerobatic !! :E

HeddW
10th Jan 2013, 13:27
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...

Runon
10th Jan 2013, 20:58
Dennis Kenyon !!!! -
Thank you for being active on this forum - a lot of freshmen flyers like myself appreciate your knowledge and advice.

HeliStudent
10th Jan 2013, 21:04
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
11th Jan 2013, 01:22
Pretending to be Mr Kenyon's attorney: "Don't answer that!"

Gordy
11th Jan 2013, 01:53
Dennis:

SLC airfield ... 5,800 ft ASL, temperature +96 degrees F

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
12th Jan 2013, 18:16
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
12th Jan 2013, 18:28
@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
12th Jan 2013, 18:32
... at the highest point (and minimum 'G') of the standard loop manoeuvre I fly, the collective lever is in its LOWEST position...

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

Savoia
12th Jan 2013, 19:03
To hell with the legals ..

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
12th Jan 2013, 19:53
at the highest point (and minimum 'G') of the standard loop manoeuvre I fly, the collective lever is in its LOWEST position

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
12th Jan 2013, 20:03
DK"Don't try this at home without guidance from an experienced display pilot."

I 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.

13th Jan 2013, 10:39
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
13th Jan 2013, 13:10
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.

13th Jan 2013, 14:03
That's one way of ensuring you retain positive G and disc loading over the top;)

Anthony Supplebottom
13th Jan 2013, 15:31
Something very graceful about large helicopters doing rolls -

SIKORSKY H-53 AEROBATIC ROLL - YouTube

JohnDixson
13th Jan 2013, 20:32
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
13th Jan 2013, 21:42
I think the term 'lowest' in this context is ... 'relative to the lateral and/or longitudinal axis.' Dennis K

Dennis Kenyon
13th Jan 2013, 22:03
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.