NZFF

This is 'another' loop that starts too low, killing the pilot...RIP...

Video here

To be honest I don't get it. If you go to youtube you can find at least 6 videos showing loops performed way too low (IMHO), ending in a tragedy like this....I'm not a pilot (yet) and don't know much about aerobatics, but shouldn't they have some kind of altitude restriction to avoid these extremely unfortunate events?

Daniel

Loops and barrel rolls are two of the most fundamental maneuvers in aerobatic flight yet they are also responsible for more accidents at air shows than any other, more than apparently more spectacular figures in which the aircraft is intentionally 'out of control'.

Anytime energy is directed downwards you are exposed to great risk and as such its vital to have clear 'gates' for an aerobatic sequence. These could be a minimum height, speed or both before commencing the maneuver.

What makes these two simple figures so potentially deadly is that it not until the aircraft is 75% of the way through the maneuver that its becomes apparent that its not looking good and by then its probably to late to recover safely. You literally ride it in.

Passing through inverted at the top of a loop and commencing the downward side, a pilot must make a snap judgement on whether he can safely complete the figure, if there is any doubt the safest and quickest recovery method is to halt the pitching movement, roll upright and pull to level. Of course this is only effective before the aircraft passes the vertical down position.

The safest way is to rely on experience and a safety margin in excess of the worst case scenario 100% of the time. Old pilots and bold pilots...

At the end of the day the Hughes 500C is not an aerobatic rated machine, so technically the rules and regulations are already there?? But this is not going to stop pilots from attempting these kind of stunts. That said many non aerobatic aircraft have been put through their paces by some very competent pilots who knew their limits and planned carefully. (I'm thinking people like the legendary Bob Hoover).
In the early Eighties I watched Joe Keeley, a deer hunter/pilot, practically turn a H500D inside out at an aishow in New Plymouth, his opening sequence was a max speed pass with pull up into a half loop and roll out on the way down. It was obvious from his skill he knew what he was doing and he certainly did not attemt a full loop. His finishing sequence was worth a mention to - he landed, had an assistant take the front pax door off and hop in with a box of toilet rolls! Then a vertical climb to about 5000ft where upon the bog rolls were tipped out turning into long fluttering streamers, the helo was pitched down into a dive and he proceded to go nuts slicing all the paper up as it slowly dropped to the ground - there was toilet paper everywhere by the time he'd finished!! Sadly Joe died in a car crash just a few years later.

I saw that Deane (I think I saw him at a Stratford Air Show as well)..amazing pilot...his Hughes had a fancy paint scheme IIRC?

Naki wrote:

QUOTE (Naki @ Aug 10 2010, 03:46 PM) <{POST_SNAPBACK}>

I saw that Deane (I think I saw him at a Stratford Air Show as well)..amazing pilot...his Hughes had a fancy paint scheme IIRC?

Yes was a metallic green colour with some airbrushed artwork. My friend has a photo of me standing beside it somwhere, we also got to sit in it too. Quite a while ago now !!
He became a legend for such things as dropping off his hunter to tie up deer to hang off the hook, then flying away and shooting a couple more while he was waiting - while still flying. He used to lock the collective and put the cyclic between knees and then shoot !! I'm sure there are pics of him in the "chopper boys" and/or other helicopter/deer hunters books that were published several years back.

Did I hear people clapping?

Tragic loss alright, my boss has a H500 in the green "Mrs Claws II" theme
Goes to a few airshows in the central north island which you might have seen displaying..

I recall seeing at WOW 94 the Wellington based BK117 Westpac chopper during its display complete a full loop , flown by Toby Clark, now the BK1117 is not exactly a small Helicopter!

Syncop8r wrote:

QUOTE (Syncop8r @ Aug 10 2010, 06:57 PM) <{POST_SNAPBACK}>

Did I hear people clapping?

I can't hear it although it's certainly possible. People who go to something to be entertained do expect that whatever happens has been put on for their entertainment, and do cheer huge explosions, and to a degree they're used to people appearing out of whatever had just exploded and waving triumphantly at the crowd.

Some of the better fireworks displays I've seen at speedway meetings started with a stockcar 'accidentally' being spun off the track into an innocent looking vehicle parked on the infield 'causing' a spectacular explosion, and one night at Waikaraka Park a few years back when the pyro guys were there for the fireworks they also rigged up a fuel bomb in the (lidless) boot of a competing streetstock which they'd rigged to go off when the car was 'accidentally' shunted from behind by another streetstock while the race was gridding up. The streetstock boys were quite happy to play the game, the resulting explosion was totally unexpected and shook the concrete grandstand, and the driver got a massive cheer when he jumped out and waved.

More recently, one of the most popular parts of the A1GP programme at Taupo a couple of years ago was the fire brigade putting out the grass fires on the infield that the fireworks had started - even the team mechanics along the pit wall thought it was part of the show.

Gary

Fauville wrote:

QUOTE (Fauville @ Aug 14 2010, 03:03 PM) <{POST_SNAPBACK}>

I recall seeing at WOW 94 the Wellington based BK117 Westpac chopper during its display complete a full loop , flown by Toby Clark, now the BK1117 is not exactly a small Helicopter!

There is a difference between a 'loop' and a 'wingover' (a rotor-over? ).......My understanding is that only Helicopters with fully rigid rotor articulation (i.e. the Lynx) can do proper 'loops' as normal rotor systems have to have positive G loading to avoid either mast bumping or excessive roll when the disc is unloaded. In that case however, to my eye it looked as if the rotor disc stalled.......

A wingover, in terms of G loading, is quite benign and can be done in almost all aircraft.

A wingover is bascially a Climbing & Descending Turn to some degree, and yea Timmo I think your correct about the G loading for helicopters, friend said the same thing who flies them..

Certainly looked like a loop from the gold pass stand, as opposed to a wing over, and mentioned in the WOW 94 airshow book as, "performed the first full loop by a helicopter at an airshow in New Zealand"

I would say it was a loop as I recall seeing the Wellington BK117 do a full loop over the Trentham race course in Upper Hutt one year.

The Lynx, now that is AMAZING. I saw a routine where it did a back flip from a stationary start, something like this:

http://www.youtube.com/watch?v=WhHkcLIgZmg

Airtrainer wrote:

QUOTE (Airtrainer @ Aug 19 2010, 01:19 AM) <{POST_SNAPBACK}>

The Lynx, I saw a routine where it did a back flip from a stationary start,

I am very sure the Lynx was the first production Helo to do a loop and first displayed at Farnbourgh 1974 , many displayed did the near same till a crash off the first type off US attack prototypes mushed in killing all at the same event on the next annual .

The Lynx and the MBB-105 have rigid rotor systems...so does the BK-117 as its based on the MBB-105...so I guess the BK-117 can loop.

deaneb wrote:

QUOTE (deaneb @ Aug 10 2010, 03:58 PM) <{POST_SNAPBACK}>

Yes was a metallic green colour with some airbrushed artwork. My friend has a photo of me standing beside it somwhere, we also got to sit in it too. Quite a while ago now !!

I also have a pic somewhere of my school mates also standing next to Joe's 500D

Not being an "egg beater" type, I wonder if one of you lads can explain to me how ANY chopper can do a loop please? I would have thought that the G's, air pressure, and the way that the air is always being forced "down" would make such a thing physically impossible. Enquiring minds want to know...

I'll have a go but I'd love a rotorhead to correct me if I'm wrong - I would imagine it's all to do with "down" being relative to the rotor plane rather than the ground.

If you tilt the rotor back the helicopter pivots around the rotor head bringing the nose up and the tail down, and as long as you hold the rotor in that plane the nose will continue to be pulled up and your forward speed will carry you around a loop.

(I'm probably wrong though )

Gary

I had always assumed only modern rigid rotor helos were capable of loops, but this is not true. I got this from another web site. Ray Prouty is a well known helicopter guru. Quote "Ray Prouty tells us that all helicopters have more than enough cyclic power to do a loop, probably even from cruise airspeed. Unlike airplanes where the pitch-authority is limited by diminishing airflow over the horizontal stabilizer/elevator as the maneuver progresses (especially nearing the top), a helicopter retains its control power all the way 'round. Rotor blade/tailboom contact would be just one of your worries." unquote. Hence why rigid rotor helos are better suited as the rotor blades wont't flap or teeter excesivley to strike boom or fuselages

Nor are these stunts old - heres some proof of the first documented helo loop - in 1949 !!
Sikorsky S-52 First Helicopter Loop - 1949

Thanks deaneb for that info and link - very interesting. I am still surprised that the dynamics of the rotors allow for a full loop, but that was certainly food for thought about the "limitation" of the air flow over a fix-wing.

If you look at the last 1/3 of the loop the heli maintains a vertical down line for some time, presumably to unload the disc and gain RPM, before he realises his proximity to the ground and yanks back hard on both cyclic and collective. Either that or he wanted to increase the down going loop radius so as to pull out closer to the ground, or match the entry level, for effect. He certainly achieved the later. Can't see the insurance company paying out either.