Helicopter Aeros & Display Flying

[Ewan Whosearmy]

Does anybody have any first hand experience of rolling and/or looping helicopters with appropriate rigid rotor heads and blades (i.e. MD-500, Lynx, Apache etc.)?

If so, are there any safety tips or advice which might be passed on those who might be interested in learning how?

Some of those i have spoken to are adamant that rotary wing aircraft should not be flown upside down at ANY time, but i am inquisitve and would like to know more of the theory behind flying helicopters outside of the 'straight and level' flight envelope.

Many thanks...

[Cyclic Hotline]

There are a variety of helicopters that have demonstrated aerobatic manouevers over the years. The most spectacular is the Sikorsky CH-53, can't get much more dramatic than rolling a big ship! I believe the S61 was the first of the Sikorsky products to demonstrate this manoueuver.

In the commercial world, there are a few known inadvertent rolls that have occurred, and the machine succesfully recovered. Many years ago, a logging S61 managed to snag a B206, after both long lines became entwined during an avoidance action. The 206 ended up inverted at the end of its long line and the 206 pilot punched off from his belly hook and recovered!

I also know of a now unemployed pilot who rolled a commercial MD500D. Perhaps the most inane activity was a pilot who demonstrated a roll in a Lama, to impress his passengers. Unfortunately the VIDEO that they shot from inside the helicopter ended up on the Chief Pilot's desk - another unemployed individual!

None of these manoeuvers are permitted in the commercial flight manuals, so the appropriate procedures are not in the public domain. So don't go rolling your R22!

[This message has been edited by Cyclic Hotline (edited 05 January 2001).]

[helimutt]

I once rolled an R22 with rather disastrous consequences but managed to mantain positive G throughout and didn't chop my tail boom off. I woke up and spilled my cornflakes!! It had been a heavy night on the town though!

[greenarrow]

Yes to the above in a Lynx AH-1 and AH-7
With and without TOW Launchers fitted!
Nice machine to do it with but keep within the 'G' limits.
Tends to bit at 85kts backwards though.
You have more cyclic movement available from the right hand seat that the left so when you are teaching the next display pilot the static flip you can run into a bit of grey hair syndrome.

[Lu Zuckerman]

The first helicopter to loop (14 times) was a modified Sikorsky S 52. It happened prior to my joining Sikorsky so it must have been around 1954 or therabouts. The pilot was US Army.

OK, so it wasn't a roll.

Then again the rolling of a B-707 was demonstrated over lake Washington during the powerboat festival.

------------------
The Cat

[eden]

I've just re-read the email I sent you and realise it didn't really connect to the thread. Anyway - it's from me. I would be delighted to chat about this topic away from this very public arena.

e

[Larry]

I have Video tape from the 1960s of the Lockheed L286 doing loops , rolls and other neat stuff.Very impressive.The Lockheed XH-51A also did some incredible flying , like flying close to 300mph in nap-of earth.
The lockheed test pilots wanted to do
Aerbatics with the AH-65A Cheyenne but the
Army wouldnt allow it.
I also have a video tape of the German pilot by the last name Zimmerman doing things in BO-105 that was simply incredible.
He ended up dying in a crash a few years later.

I beleive the Bell 222 with the 680 rotor did rolls and possibly loops and lots of other interesting Aerobatics.

The CH-53A did loops and rolls but was at a very low gross weight and needed the rotor head and drivetrain repaired/replaced.

I know Sikorsky did some amazing stuff with the S-67 Blackhawk during its testing
until it was crashed at the Paris Airshow in 1973.

[widgeon]

The german pilot was Ziggy ( Hoffman I think ) , He died in Pensylvania doing some aerobatics in a 105 for a film with Nick Cage .(The final cut had a 500 as the bogey)
I have a copy of the aerobatics video and it is very impressive .

[Larry]

I knew the German B0-105 pilots name had a Z in it.

So you also have a copy of the tape...
....does yours have the BO-105 flying thru the German forest in nap-of-earth ?

[rotorque]

That French machine the 'Tiger'I think its called did a full aerobatics display over Sydney Harbour early last year. The whole thing was displayed on national television. It was here on evaluation for the Australian Army - It was also here that it crashed while doing night ops shortly there after.

[eden]

His name was Zimmerman - unfortunately I belive he's now rolling and looping at the great heliport in the sky.

He was quite a character

[SPS]

Helimutt -

I had a similar dream last night.

Did it in an R22 HP running on 3 cyls. only.
Didn't have any doors fitted.

Lost my map (again) which I had only just replaced....Don't you just hate it when that happens!

[widgeon]

There was a story ( maybe an urban legend) that one of the Westlands pilot tried a roll a lynx too low and ended up putting a permenant bend in the dogbone ( lead lag thingy) . BTW I believe there are 2 pilots in the 105 video.

[seismicpilot]

The rusky mil mi-34 Hermit claims the most aerobatic capabilities. Demos at airshows have been impressive too.
It's mainly used as civ ltwt, 4pax single pilot ops; police, patrol, evac, etc.
cost 300K USD, but can get one much cheaper if you have ties, or better yet family in the mafia (steal for under 10k....) Parts not difficult either, maint is easy and do able with translated manuals.

"Apart from high performance, the Mi-34 differs from western aircraft in economics of operation, maintenance procedures and reliability. In the future the Mi-34 will be operated "on condition", needing no overhauls. Its initial lifetime is set at 5,000 flight hours or 25 years. DOC is about 100USD/fhr."

[Larry]

Does anyone know how many Mi-34s have actually been built ?

Seems like an intersting helicopter.

[212man]

I've seen a Sikorsky promotional video showing the 76 rolling and pulling through the vertical from level flight. Never been past 120 degrees in one myself though.

------------------
Another day in paradise

[seismicpilot]

Larry,
this is what I know from rusky sources and friends over there: it does run on a radial piston, mounted in rear.
Heli came out for debut in '88 and boasted reliability, low DOC, and esp it's "fully aerobatic" capabilities. Not until 96 was is put into substantial production (well, goals of 50 to be put into service, mostly police work).
"Joint stock company "Mi light helicopters" specialises in development and production of the Mi-34S helicopter and its modifications, as well as sales, maintenance and technical support for Mil aircraft in service, pilot and ground crew training. Production of the MI-34S is set at Arseniev-based Progress factory with a yearly manufacturing capacity of 350 airframes.""

seems like a fun ship! nice looking too.

[Pinger]

Does the name Denis Kenyon ring a bell anywhere?

Those of us who have been around the UK rotary world over the last 15 or so yrs will know of this extraordinary man and the even more extraordinary things he can make an standard piston Enstrom do (don't laugh, it's one of the strongest and most agile machines around).

His displays at Helitech are a mind boggling series of impossible low altitude maneuvres that make the military displays look utterly tame.

Aerobatic is, I believe, defined as over 30' roll or pitch which is pretty ornery, the magnificent Whales (bigger and greyer than Sharks) ripped that definition up in a 3 ship formation in the early '80s. DK's displays (solo) go at least 3 times over those parameters, I never saw a military helo pitch to 110' nose down at 200'agl and roll 360' in the vertical before pulling out at zip feet agl to pitch right into a vertical torque turn....up and down...

Aeros in helicopters? You'd better believe it!

I never got anywhere close to those attitudes in Hughes 500 and Gazelle and God knows I tried, at a safe altitde. There are still Giants walking this Earth!!

[Larry]

Pinger
I noticed you have flown both the H-500 and 341 Gazelle.Can you please give me a comparison of the two ? I know both are very manuverable but which do you prefer in regards to flying qualities , power , agility ,vibration ,comfort ,Etc ?
And if you could own one of the two which would you prefer ?

Thanks
Larry

[hover lover]

Well for anyone who wants to practise loops in a (civilian) ((gyroplane)) there is at least one firm that builds one sturdy enough to loop if you've got the moxie to loop a GyroPlane -
"Vortex Breaks New Territory for Gyros". Jim Vanek performs world's First Loop in a Vortex gyroplane at the PRA Convention in Mentone, Indiana, Summer 1997.
If you would like to witness this for yourself, tapes showing five loops & more exciting flying footage are available.

hover lover

[Randy_g]

212Man, I just watched a show on the Comanche, and one of the test beds was what looked like a 76, but it had a version of the Comanche's fan tail. They showed it doing rolls and looping, as well as showing the 53 doing a roll. That is what I call impressive !! :)

As for any civilian ships doing any of those maneuvers, well only heard rumours. Most of them including the 500. Can't think of any operational need for doing either, except for that one-in-a-million emergency.

Oh well that's my 2 cents worth.

Cheers !!!

Randy_G

BTW Ewan, my tip on learning aerobatics; go find a reputable seized rotor (uh fixed wing I think they might also be called :)) aerobatic flight school, and go up with a qualified instructor. Learn in something designed for it, and with someone trained to instruct aerobatics as well.


If you can't stand the heat...

then turn up the airconditioner !!! :)


[This message has been edited by Randy_g (edited 07 January 2001).]

[212man]

Yes, Sikorsky did trial a fenestron version of the 76, I think it was going to be called the 'D' (but don't quote me). The film I have seen was of a standard 76, but in military trim (some forces use them eg Phillipines) and it was doing all manner of things.

I agree Dennis Kenyon has a spectacular show, but how prudent some of his manouevres are is a moot point I think.

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Another day in paradise

[Speechless Two]

widgeon - yup, you're right about a Westlands test pilot bending a Lynx during a slow roll - must have been late '72 or very early '73. He didn't continue in that employment(!) and I ended up working for him in '73 on a new offshore operation. He later went on to work for a rather well known Gas exploration company in a senior aviation role.

I must agree with the remarks about Dennis Kenyon - I have never seen a helicopter display like it and have to admit turning away during some of the manoeuvres as I hate seeing helicopters crash - but he always seem to pull it off.

[Pinger]

Larry, here goes.

I'd say handling and agility are similar, though with hydraulic controls the Gazelle is perhaps a bit easier to fling around. Both are smooth in the cruise and vibs only go up when you try to go too fast. Neither will realistically cruise over 120Kt.

Both have stacks of power, but you'd have to look at manufacturers figures to see how much fuel you can carry with all seats full.

Regarding full seats, the Gaz has a decent sized cargo compartment even for 4 people's luggage, the H500 has none. Not even room for a toothbrush. Also rear pax have a pretty grim time in the Hughes. Its cramped, noisy and vis is poor. If you want to carry 4/5 people it has to be the Gaz, 3 in front in the Hughes is too cosy. The 'one cabin' layout of the Gaz is far better for pax, it also scores with easy access due low floor hight, getting into a H500 even on "low" skids is a three step climb, high skids makes it mountaineering. That said the Gaz is a lousy charter machine as the seating is still very military and the cabin nowhere near the comfort levels of even a JetRanger.

Gaz loses heavily on it's engine. The Astazou is a fine engine and far more robust than the Alison, but it time-exs at 2200hrs if memory serves and the cost of a recon one (if you can find one) is egual to the total value of the machine, so the economics just dont stack up. Parts may be a problem with the Gaz, few were made for civvy street and there may be certification/compatability problems on some items. DOC of the Gaz is said to be as high as a Twin Squirrel, H500 is pretty cheap to run (no hudraulics and good spares availability)

I always liked the ability of the Gaz to stop the rotor with the engine running, the disk is too low for rotors-running changes anyway. Fenestron is safer than a tail rotor and the ogre of fenestron stall is much overplayed as it is extremely rare even when provoked.

If I had enough money to buy a helicopter I would not have either, a Single Squirrel is leagues ahead in every respect. For practicality I think a B206 beats both too.

However if I had to chose I would prefer the Gaz, cos if I was that rich the cost of a new engine would not matter too much!

Does that answer the question?

Oh, and if you ever get one, can I come for a ride?

[Larry]

To 212MAN:
Yes ,Sikorsky built a Fantail(Fenstron)
equipped S-76B but it was only a test bed for the commanche program. Nick Lappos (Sikorsky Test Pilot) said they needed to put put a couple hundred pounds of weight in the nose to keep it within CG.I don`t think Sikorsky expected to put a Fantail S-76 into production. As a matter of fact there`s
a new "quiet" tail rotor design that`s supposed to be incorporated into the S-76 in the (near)future.At least thats what some Sikorsky people told me.
Ive seen a photo from about 1995 of a Bell 230 with a prototype "Fenstron".
Ive also seen a AS-350 with a fenstron ,
i didnt know about it till i saw a picture
(if anyone wants to see the pic let me know and ill post a link).
Finally ive heard about a Puma testing a Fenstron but havent seen a picture but i have seen a artists rendering of a Super Puma with a Fenstron.From what i understand the weight penalty and power requirements of a Fenstron in this large a helicopter is to high to be economical.

[Larry]

Pinger
Thank you very much for your thoughts.
every thing you said is pretty much what i thought. Really the best bet is a Jetranger because its almost like owning a Ford ,
easy to get parts and everybody can fix it.
The Squirel (or as we call it ASTAR , unless it powered by the Lycoming 101 then its called an Exploding Star !!))
is actually very popular in the Los Angeles area as LA City Police fly them and all the
TV Stations fly AS-350s for ENG. There are
also many used for Private/commercial use.
Finding people to repair the AS-350 and
obtaining parts is quite easy.
The Gazelle has always been exotic around here and is getting more so.Parts are not impossible to find but can take time to receive. Its not a good commercial machine but im looking for one for private use with the intention of flying about 150 hours a year. With this usage an engine with 750 hours remaining will last 5 years. (the overhaul time on the Civil 341Gs engine is
1750 hours). I hear the engines are near bullet proof and go to TBO if not abused.

The 500 series is extremely popular with
police operations in Southern California and id say 80 percent of Police Helicopters are
either 500Es or the Notar( the 520 NOTAR is
terribly underpowered considering tempratures
stay between 70-80degrees during the year and
90-105 degrees during the summer). A few Depts fly the 530F and it has performance to spare even during summer and desert operations.
Parts and maintenance on a 500E is no problem around here.The Cockpit is a bit tight and sitting in the back is not fun nor comfortable.
But the 500E is much more sporty then a 206B and is much faster.

Its looking more and more like the Jetranger is the most resonable machine for
personal use.
But the Gazelle has it all , Beauty ,
, speed ,power ,decent cabin and is very exotic but i believe im about 15 years late for it to be resonable to own without breaking the bank.
The AS-350 would be of interest but the prices are just to high , as is the Bell 407.
Both would be at the top of my list if they were more affordable.

[Cyclic Hotline]

Here is the AS350Z, with the fenestron. It just so happens that our Eurocopter rep e-mailed this picture the other day!
http://perso.wanadoo.fr/lionel.laporte/image/ecureuil/fwgmq.jpg

Sikorsky also installed a fenestron to a modified S-67 Blackhawk. The machine was configured with S61 components, so the tail looked abnormally long and skinny, but was flown successfully.



[This message has been edited by Cyclic Hotline (edited 07 January 2001).]

[[email protected]]

Ewan - getting back to the original thread - don't even think of trying it yourself - yes some helicopters can be looped and rolled but unlike a fixed wing aircraft the fatigue penalties on the airframe are impossible to calculate without having a fully instrumented aircraft. You might survive a loop or 2 but what happens when the next guy gets in and the intermediate gearbox seizes or the tail rotor fails? Helicopters are not designed to operate in this manner even though some, like the Lynx are particularly good at it (try finding another helicopter that can backflip from 1000').
As someone else suggested - try a fixed wing if you want to aerobat.

[leading edge]

Larry

Sikorsky are indeed coming out with a new "quiet" tail rotor on the S76 in the near future. It seems that they need to be able to compete with the 139 and the 155 with the S76 which is now well over 20 years old (and a very fine helicopter)

Latest product briefings have outlined several improvements including the quiet tail rotor, sensible move, as I believe that environmental and noise concerns are one of the biggest hurdles to be overcome by helicopters if we are all to have a long term viable and sustainable industry.

[Larry]

Cyclic
Do you know when the Fenstron was tested
on the AS-350Z and will it be incorporated
into the new EC-130/AS-350 ?
I saw a EC-120 operated by the San Bernardino Sheriffs Dept.a few months ago and was VERY impressed with the quietness of the helicopter itself and the fenstron in particular.
I was expecting to hear a AS-365 howl or a Gazelles whine but instead it was as quiet as the MD-520N "Notar" taking off beside it.
If Eurocopter can do the same with the AS-350/EC-130 they`ll have another helicopter perfect for the Law enforcement , ENG ,Tour
and other markets requiring low noise levels.

Now if Bell can quiet down the 407 !! That is one annoying Police helicopter when it circles your house at 2am......LAPD had four
for 4 years.....now replaced with the slightly quieter AS-350B-2 ASTARs.

[Lu Zuckerman]

To: Larry

Speaking of quiet helicopters, when I worked on the Apache program Hughes was developing a “Quiet helicopter for DARPA (a scientific government organization). They took an H-500 and mounted it on a framework. They had the capability of cutting the rotor drive and tail rotor drive and connect them into a dynamometer. They could also run it as a conventional helicopter running both the main and tail rotor pulling pitch in both. The purpose of these tests was to determine what generated noise and at what amplitude and frequency.

After collecting these data they incorporated fixes on the airframe so it would not vibrate and broadcast the vibrations at the various frequencies into the surrounding air. They incorporated a five-blade rotor head and incorporated an X tail rotor, which allowed them to cut the rotational speed of the rotor and tail rotor. They then put a muffler on the engine exhaust and started to fly it.

The helicopter flew about five hundred feet above the other onlookers and me and it was just like Airwolf. All you could hear was whoosh. No blade noise, no tail rotor noise and no engine noise.


------------------
The Cat

[whatsarunway]

larry..........> ec130???

[Larry]

Whatsarunway:

EC-130 is the new designation for the
AS-350 and is supposed to be unveiled in february at the HAI Helicopter show in Anahiem Calif.Im not sure what will be new about the helicopter but im going to the show and will post what i learn ASAP.

Might it have a Fenstron ????

Larry

[tailrotor]

Greetings gents,

W.r.t. the thread...the only machines that I have personally seen doing any form of aerobatics where back in S.A where I saw my instructor do consecutive roll's in a BK117 and on another occasion I was witness to the ROOIVALK doing a barrel roll followed by a loop.This is part of it's demo that it does at airshows all over the world. Also included in it's demo is a 60 -70 knot climb out..backwards !!! and a demo of sideways flight at the same speed...

Not to shabby huh ?

Interesting thread by the way.

Cheers.

------------------
** To hover is devine but to MOO is bovine **

[EESDL]

Using the thought process of:

"Well we might aswell show you this because you'd only kill yourself if you tried it first..."
Once you were Combat Ready in NI, you were dragged off and shown what Walter was actually capable off...quite an eye opener (all of them)! Needless-to-say - no one is going to admit to looping a non-rigid-anything RAF helicopter but it could pass the time of day when you're waiting for Uncle Dermot's Rifles to finish their cup of tea at the local farmhouse!

[helisphere]

The S-52 was the first sikorsky to loop. It was in 1949, and the pilot was Harold "Tommy" thompson, he's still alive and has footage the loops. Funny thing, the FAA (then CAA) didn't like what he did and they took his license away, but only for a few days.

I have also read that a Piasecki tandem looped successfully sometime in the late 40s due to a mechanical malfuction.

As for gyros, I've seen old black and white footage of the old gyros with wings tail and fabric covered blades doing consecutive loops at low level.

If any of you has ever seen a good model helicopter pilot fly, then you know that a helicopter is capable of almost any maneuver you can think of if the aircraft is properly designed and rigged. Obviously none of the people out there designing and building full size helicopters seem to find it of much value or they would have built something by now.

It is not illegal to do aerobatics in all helicopters. You can do anything you want if you certify the aircraft in the experimental category.

It seems to me that people in the helicopter industry shy away from this aerobatic stuff. Just look at all of the responses on this forum. I'm not saying anyone should go do aerobatics, the aircraft just aren't designed for it. But what if this same subject was brought up concerning fixed wing? We'd be talking about Pitts specials, extras, eagles, sukois and all kinds of homebuilts. And all of the maneuvers we've done and techniques. The fact is fixed wing aerobatics aren't anymore useful or easier to make happen than rotory winged aerobatics. The only reason we rotorheads are not out flying upside down is that no one makes any helicopter equivilants to a pitts or an extra.

[This message has been edited by helisphere (edited 14 January 2001).]

[helisphere]

Just heresay but someone told me that the EC-130 was supposed to be much faster, like 150kt cruise. I guess they wanna outrun the 407.

[widgeon]

there was a joke going around that the mod kit for the 407 AD included a blanking decal to blank out the 0 in the 407 as the performance after the AD was close to the old 47.

[Grey Area]

In answer to the original question. I have looped and barrel rolled Lynx.

My advice? If you want to do it, find a way of doing it legally and with someone who has proper experience of the manoeuvres. I would strongly recommend you do not do it without the above, otherwise check your life insurance and don't make any holiday plans.

[ShyTorque]

I used to display a military (7.4 tonne green plastic) helicopter. My brief was that aerobatics were anything more than 90 degrees of pitch or roll and were not to be done. Some of the manoeuvres we worked up to were quite a bit more than those limits, but the display was cleared by the hierarchy). It was obvious to me that the aircraft was quite capable of looping but rolling was less certain because of physical limits to lateral cyclic movement; on some manoeuvres I used to hit the lateral stops. After I moved on my sequence was used by other pilots. The display was banned after two pilots had nasties with the tail rotor hitting the tail cone (not theoretically possible due to hinge limits). That confirmed we had taken things as far as they could go with that aircraft. People said it looked good from the ground anyway.

After I had moved on to more aerobatic fixed-wing things I was invited to attend a display flight safety briefing at fixed wing CFS. A Westlands video of a Lynx looping and rolling was well received BUT! The Westlands rep stood up and pointed out that the aircraft had suffered gearbox damage as a result. He strongly stated that the Lynx aircraft should NOT be flown like this without factory supervision as damage would occur.

[Capt Tercrue]

Stu Collins was the Westlands TP that did the roll that caused the problem in the late 80's early 90's. (See the Westlands video "Over the Edge").
His problem was that he had no idea how to do it and didn't enjoy that sort of flying anyway!
On the vid it's noticeable that the tail boom is a different colour to the rest of the aircraft, the reason that is claimed is that he bent the original trying to do the manoeuvre.Which is borne out by the piss-poor standard of the roll that is shown on the vid.
The problem with rolling(aileron roll or Barrel roll)the Lynx is that there is a severe couple caused by the combination of pitch and roll that results in an uncontrollable T/R breakaway.
This is exacerbated if the Lx is fitted with TOW booms(lots of dirty vortices ingested by the T/R).
The answer is quite simply, if you're not TAUGHT how to do it from someone who knows - DON'T.

[helisphere]

Yes, but how would anyone ever know if someone didn't first try it with out knowing?

[SARcastic]

There was an Army Air Corps instructor (can't remember the name), who regularly looped a Gazelle circa 1978/79.
Anyone remember that far back ??

:rolleyes:

[Roundout]

.....you don't see everyday!!

http://www.airliners.net/photos/big/t/tues-8.jpg

[VPL]

One way of getting ya Fags from the back seat I suppose....... http://www.pprune.org/ubb/NonCGI/tongue.gif

[VPL]

Roundout.......
Your right its not often see "Army aircraft" serviceable and flying everyday.........anymore......

[whatsarunway]

I Have a heli that looks loke that.........
so let me see , down collective , aft cyclic , change pants.

[SPS]

All of ours look like that but the ground is at the top of the frame as well......

[B Sousa]

Intersting Photo and somewhat hard to tell which is inverted, the picture or the aircraft. If its the aircraft, Im sure someone has already ran sniveling to the commander about what some pilot did. If Identified, it could be a very expensive photo.
(Not a lot of Blade coning)
Any guessing on this one??

[Lu Zuckerman]

From the looks of the shadow on the airframe the helicopter is upside down. The question begs answering,"why did he do it?"

------------------
The Cat

[hoverbover]

I think the answer is he probably didn't know a photo was being taken !

I guess he would get away with saying he was flying over a lake and the sun was going down.Providing his CO wears glasses!

But hell I'm only jealous, i'd love to be able to fly well enough to even think about how you would attempt it (not that I would !!)

Regards
hoverbover

[RW-1]

Besides the shadow, I took it into photoshop to blow it up to look for evidence of, shall we say "Creative touch ups".... None found. My evidence for realism would be long wire antenna too. Hard to get that inserted against that backround, etc.

Interesting pic though. Just like this one (A buddy of mine having fun, of course this bird can stay still for the camera inverted :)):

http://albums.photopoint.com/j/View?u=965015&a=7070809&p=39438682

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Marc


[This message has been edited by RW-1 (edited 08 March 2001).]

[nomdeplume]

Lu says "Why did he do it?" begs answering.
Possibly because .....
... (assuming he lived to tell the tale) he proved it could be done
... and he had the skill to do it
... it was a challenge to his piloting skills
... it was that fine line between bravery and recklessness which some people seem to find irresistable
and just because, like Mt Everest, it was there to be done!

All just wild guesses, I'm afraid.
As a lowly PPL, I'm more than happy if my number of landings matches the number of take-offs. I leave my aeros to fixed-wings! :)


[This message has been edited by nomdeplume (edited 08 March 2001).]

[PurplePitot]

This looks like a ‘Split S’ manoeuvre where you pull up slightly from around 100 knots roll it inverted (disc unloads) and then pull it through with aft cyclic taking care not to jackstall. Either that or a very sporty wingover.

Why did he do it? Because it’s fun, which is why I try and do at least two a day…………

[hoverbover]

On my flight home this evening I remembered AN answer to the question "why did he do it" .

For the same reason dogs lick their b!!!s...... because they can!!!!!!!!!!!! http://www.pprune.org/ubb/NonCGI/tongue.gif

Regards

hoverbover

[Roundout]

Interesting comments - I had the pleasure of flying the 350B for a year about 15 years ago - greatest all-round chopper I've ever flown - sadly consigned to fixed-wing now - but in my time I'd never have dreamt of doing something like the photo shows - and I thought I had a lot of fun :)

[John Eacott]

This sequence of photos were taken over Lake Burley Griffin in Canberra some years ago, and are quite genuine. It was a barrel roll, done by 5 Sqdn as part of their air display routine back in 89 - 90. Being Army, no explanation was deemed necessary :)

The AS350BA's are coming up for sale soon. Take a note of the rego........

[Lu Zuckerman]

It appears that many of you are in awe of the pilot doing the loop/roll and some of you expressed a tad of jealousy of his being able to do it. What you don’t take into consideration is that if he couldn’t maintain 1G during the maneuver he may have overstressed some of the dynamic system. And, as some of you had alluded he may not have told anybody about it and possibly didn’t even realize he was being photographed in the process. If in fact he had overstressed a component maybe the next guy to fly that helicopter would be killed when that part failed. To paraphrase an old axiom,” When you screw with the bull someone else may get the horn”.

Now I’ll get off my soap box.

PS A long time ago a test pilot did a slow roll in a 707 in full view of thousands of spectators at the Seattle Unlimited Power Boat Races. He was severely chastized and when he asked why he did it he replied that he knew he could do it and as long as he maintained 1 G during the maneuver the aircraft would not be damaged. He did and, it didn't.

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The Cat

[VLift]

And his name was Tex Johnson I believe.

[John Eacott]

LZ,

To elaborate on my previous post, the barrel roll was part of 5 Sqdn's air display routine, and was done on the basis that it was a positive G manouevre. Eurocopter are reputed to have been consulted, and gave tacit approval. The routine was flown for some time over a period of a year or so.

Wiser heads then prevailed, and decided that the risk involved did not justify the flight display, and the barrel roll was dropped from the display routine. AFAIK, engineering found no undue stress on any of the machines used, and they are still in service ten years after the displays that were pictured. The pictures, by the way, were in no way clandenstine, since the air displays were always performed for the public, with the full knowledge of the powers-that-be.

[Hoverman]

Which is the most manouv, manoeou, man ... agile helicopter you've flown?

[volpe]

Dauphin are good for their size. You can do heaps out of wind etc. and are quite forgiving when stressed.

[twistair]

When speaking in terms of aerobatic capability in can be Mil Mi-34 (when only 1-2 aboard) - I didn't flew it but I was really impressed with it flown over the MAKS Airshow in 1999 and 2001 - I believe it's hard to find any other light heli doing loops so easily. Nothing surprising - it was primarily designed specially for USSR national helicopter team training.

Sincerely,

Alex
Light Helicopters and Gyros in Russia (http://galsaero.al.ru)

[quillshaft]

Bo105 or British Mil Lynx. They are both very agile aircraft. ;)

[Capn Notarious]

I once saw an MD520N doing some rather clever gyrations. This was at the all England Championships, Wroughton Wiltshire, during the early 1990`s. So to extend the thread and bring in all of the experianced pilots: Could a tail rotar/fenestron, be more or less useful than the coanda effect of MD fame; in identical circumstances and how could this be tested?
Just to be

[Droopy]

EC135. But that might be because I haven't flown a Lynx.

[quillshaft]

Yep EC135 too, I fly the 135 but as yet have not "explored the envelope" fully yet. She is a very stable platform when executing some very challenging manoeuvres i.e. chasing a stolen car in a built up area. :cool:

[Fortyodd]

Lynx. While Westlands may have F***ed up everything else about the aicraft at least they got the Man-Hoover-Ability (I couldn't spell it either) right. :D

[greenarrow]

I must say the Lynx would be hard to beat, even with the TOW launchers fitted and loaded. The early Mk1's were a bitch upside down as you tended to run out of Tail Rotor and bottle.

[JohnCarr]

Or when seeing who would bottle first on a pairs pedal turn!!! :p

[Marco]

Lynx without a doubt!

[pedroalpha]

I did like the Scout AH1 - sensitive, unstable and pure fun.

[John Eacott]

Apart from a disgusting lack of TR authority when heavy/high, the BK117 is heaps of fun. At mid weights, it can be encouraged to provide as much manoueverabilty as can be wished for in a civvie ship.

Now the pilot of mine who scored a ride in (and poled!) the Apache demonstrator at Avalon professed that it was an agile beast, but he would, wouldn't he :D

[Ancient Pelican]

I saw an MBB film about 10 years ago of a BO105 doing some very impressive things. One of them was forward movement(not sure if it would qualify as flight) tail first and inverted!!! He did a whole series of rolls, loops and hammerheads, the film was very impressive to watch. Never had the courage to try them myself, but the BO105 is fun to fly and very very responsive to control movements.

[buttline]

Don't worry, I've no intention of trying it - just curious as to how it's done. Does it require a rigid head? I'm guessing the trick is to keep the disc loaded through the roll?

[[email protected]]

A true barrel roll requires a constant rate of pitch and roll throughout the manoeuvre which helicopters cannot achieve as they run out of speed. Most rolls in helicopter aerobatics are the equivalent of an aileron roll in a fixed wing - that is to say they are a product of lateral cyclic. The ability to achieve a rapid roll rate is required so hingless or semi rigid rotors have the advantage here due to increased effective hinge offset and therefore control power. The problem with snap rolling a helicopter is the twisting force experienced by the tail boom - the mass of the TR, TRgearbox and drive shafts has a lot of inertia.
The Lynx display manoeuvre called the Eagle roll starts with a gentle nose up to reduce the speed followed by full right cyclic and a lot of right pedal. The result is spectacular both from inside and outside the aircraft but you pay the penalty of vastly reduced component times and increased servicing for the pleasure.

[Aro]

Wouldn't barrell rolling a semi-rigid not likely result in most undesirable rotor seperation?

[Nick Lappos]

Having rolled, split S'd and looped several helicopter types, and also helped lay out Comanche's rotors for the air combat mission it accepts, here are some thoughts:

1) The barrel roll is made with a pitch up followed by lots of lateral cyclic. The aircraft scribes a spiral flight pah and holds positive G. This is the common helo roll, albeit with some speed loss as Crab suggests.

2) A rapid lateral stick input will produce zero or negative G at the 180 point, and is very much like the aileron roll in an airplane.

3) These maneuvers do not tax the tail cone or tail plyon at all, those components are designed for very high yaw thrusts, beyond anything experienced in a roll. The tail rotor blades, hub and shafting, however, are subject to lots of flapping and precession forces, and can achieve limit loads at high roll rates, maybe 100 degrees per second. Fantails like Comanche see no such forces, and so do not inhibit rolls at all.

4) Loss of control is a big factor in most helo designs due to the issues of rotor control loss at zero G. These maneuvers are quite likely to cause rotor contact at the hub, and on the fuselage, that will be catastrophic. Teetering rotors are verboten in this discussion, and low offset articulated systems are marginal.

5) The barrel roll is a semi-useless maneuver, basically for air combat when a rapid slowdown is needed (the spiral flight path is much longer, so excess speed can be burned off while tail chasing a bogie), the aileron roll is used to rapidly change the direction of the lift vector as a climb/descent or turn entry maneuver.

6) Helicopters in air combat do very different things, and they are quite a bit more maneuverable than airplanes, just not in the airshow sense. Most helo air combat will involve rapid turns and then weapons engagements, and little vertical maneuvering. Classic WWII/Vietnam airplane air combat involved jockying around to align the fixed guns with the bogie, a style of combat that is now basically obsolete. All aspect weapons and supermaneuverable aircraft (F-22, Comanche) will make snap turns and rapid shoots much more the style.

[SASless]

Nick ol' bean!

Being an old (sorry) err...former Cobra pilot....would you do such maneuvers in Bell built machines with their underslung, teeter totter, type rotor systems? Am I being a scardy cat here or would the a bit of mast bumping not occur just prior to rotor head disapperance?

Having flown the BO-105 and BK-117.....and being a real man about town (in my own mind anyway) I could never get the courage up to go past about 135 degrees angle of bank.....always chickened out and tucked out towards terra firma!

But then in Chinooks....we developed gentlemanly habits of flying....things like coffee makers, canned music, and walks about the cabin thanking the passengers for flying with us.....thus radical maneuvering only took place on the ground in ops when trying to dodge a flight that had a two way rifle range (borrowing Nick's phrase here) as a destination.:rolleyes:

[Nick Lappos]

SASless,

Doing anything but straight and level with moderate turns in a teetering rotor is taking a chance. The control is so very much dependant on maintaining positive G that any screw-up makes the situation a real catastrophe.

Aerobatics in helos in general should be left to the bar talk. Doing this stuff without a test pilot and a good insurance policy is not too bright, definately illegal, and not conducive to longevity (to paraphrase Bomber Harris).

Nick
:D

[blave]

Nick,

This discussion brings up something I've wondered about for some time... I've read most of the available books about Cobra ops in Vietnam - and am under the impression that the pilots would regularly perform maneuvers in getting set up for a "run" that would appear to be just the sort of thing that a teetering rotor wouldn't like very much - i.e. an unloaded dive. Were these guys just real careful to always keep the rotor loaded?

Also, I have some OH-6 training tapes from '67/'68 that show "wingover" type maneuvers... I have the same question about those; it seems like that would unload the (non-teetering, of course) main rotor.

thanks,

Dave Blevins

[Nick Lappos]

blave,
The rocket run entry used to be done as a bunt or low g pushover, but in 1969 an emergency flight warning went out for Cobras to avoid the low g. We simply pushed over a bit more gently, with no difficutly. The dive is a 1 g maneuver, and no sweat.

We all did "wingovers" or target returns, and they made us feel quite aerobatic. As long as you pull 1 g or more in the whole maneuver, it could be done safely.

The OH-6, and the UH-60, AH-64 and the S-76 all have moderate offset main rotor heads (4 to 5 %) that permit quite a bit of control at zero g. These aircraft can all be coaxed into impressive shows. We express the percent hinge offset as the ratio of the flapping hinge to the rotor radius, so a 25 foot rotor radius with the flapping hinge 1 foot from the center of the mast has 4% offset. This is a measure of the snappiness of the cyclic, and also of the control power remaining at zero g. Later in the week I'll post a little discussion of hinge offset for those who wish to go deeper into it. For a BO-105/BK-117/RAH-66 the hinge offset is in the 10 to 15% range, ideal for such messing around.

[SASless]

Nick....now I have never been accused of being "bright" and afterall...heck...I read about it how to do it....any well gee....but you are right.....my internal self preservation gyro...has never let me down for those intentional misdeameanors I have been tempted to commit. It has however, deserted me on more than one time when unintentional felonies have occurred!

[Hone22]

:(

-------------------Quote N Lappos------------------------------------
Aerobatics in helos in general should be left to the bar talk. Doing this stuff without a test pilot and a good insurance policy is not too bright, definately illegal, and not conducive to longevity (to paraphrase Bomber Harris).



:( Brings to mind the bloke in the ENG MD600 (LA?), last words were something like "watch this" as he attempted to roll the ac in front of friends alongside in a R44.

They got to watch as the ac chopped the tail off mid manouvre, plummeted to earth killing pilot + cameraman.

Kinda ruined everyone's day:(

[HeliMark]

Hone22, the NTSB report is #MIA00FA102. Occured in Florida. The pilot apparently was doing a wingover that turned into a hammerhead? It seems that he unloaded the blades a bit too much.

[Low N aahhR]

If you want to barrel roll things - then get a plank and do it in that. Helicopters are great fun for lots of things...but let's be reasonable about it!

Keep the blue above the brown. Just remember that ones' rotor blades have a nasty habit of coming down (or up) to meet you if you're doing something silly.

I say this as a young pilot who intends to get old!

Flysafe (and the right way up!!)

[FLIR]

Buttline,
Having in my past had the pleasure (if that's the correct word) of practising and performing limited aerobatics in the lynx heli I would advise you not to even think about it!! The accident always starts with "I wonder if" unless you are with a test pilot in a competent machine!!!!

Nick,
Do you know of, or remember a certain F. Zimmerman (think thats the correct name) who used to throw a BO105 around a few years ago - always thought that he was a guy with a death wish!
FLIR

[Nick Lappos]

FLIR,
I do recall his name and fame, I saw a video he performed in while flying a PAH-1 BO-105. It was awsome.

Also Sigfried Hoffman, who died mysteriously while filming a movie in the States, even with his experience, something got him.

I have done quite a bit of helo aerobatics, many of the Discovery Channel shots of split S or roll maneuvers of Sikorsky's are mine, but I admit I still haven't figured out why.....

No other flying machine can pull to a stop, pedal turn and then sprint away. To toss a helo around until it performs like a Spad proves little, I think. Much better to do what we do best, and get better at that.
Nick

[buttline]

Low N aaahrr and Flir,

I respectfully refer you to the first sentence in my original post..."Don't worry, I have no intention of trying it but.." Actually, if the truth be known, I'm a bit of a coward now I've past 30!

I've seen it done in Lynx's, Gazelles and of course Nick's stuff on Discovery but they never show what's going on with the controls...

[attackattackattack]

I've sat in Lynxes while the QHI beside me demonstrated back flips. Fun but very scary. That, more than anything else confirmed where my own limitations lie. The machine might be able to do it but not if I'm the pilot!

[T_richard]

Okay can a civilian ask a question?

Thank you. Is it really possible to fly a heilocopter up side down or is a loop de loop sort of a controlled stall that you hope to come out of before the Laws of Physics start working against you? If I didn't ask it correctly try it this way is the photo with the horizon upside down and the binoculars floating in midair real or PhotoStudio?

Thanks

[Gunship]

Lo Richard,

A quick answer .. yes certain helicopters CAN do a loop like a BK 117 (with certain mod's like clipping part of the vertical stabilizer)

The big criteria is the Rotor HEAD must be of the Fixed - type and not the type that you find on a Allouette / Gazelle / Puma or Mi-24 for that matter .

They all have dragging hinges and use hydraulics to lead and lag ... eischhh this is a long subject - where do I start ..

To answer you question - yes they can and a very well known video clip is of a massivve CH53 "jolly Green Giant" doing a slow roll ... sorry ran out of power om Laptop - power out !

Gunsss

[T_richard]

I just did a google search for a CH53. Somebody looped that beast up and around? It looks like a hippo with a whirly gig on its head. Thats the most ungainly 11 tons Ive ever seen. How cool

[Gunship]

Now that you have seen it Richard ... imagine a slow roll ... I am searching for the video ... can not find it on my hard drive and yes ... damn - I had it ! :mad:

Take note : Slow roll NOT a loop - maybe it can do one from 20 000 vt AGL ? :p

[Flying Lawyer]

T_richard
I wasn't 'correcting' your post, just hoping to tempt TC to tell us more about the pic. I should have added a ;) .

[T_richard]

Excuse me guys

Would someone please clarify for a civilian what a helio can do. I recognize that helios come in different shapes and sizes. I suspect that chinooks handle very differently then a cobra, what about a Hind M24?, or a Bell. I don't expect a primer on every airframe made, just an short outline of what a frame of a certain size can do. I know from years of experiance what I can do in different power boats and sail boats. Happy to share info if you care

Basic can you loop a helio for real or do you just throw it up and hope it comes through the loop before you run out of air?

Thanks

[Lu Zuckerman]

To: Gunship

They all have dragging hinges and use hydraulics to lead and lag

Please explain what hydraulics are used to effect lead and lag.

:confused:

[Jez]

T_Richard

The answer to your question is YES. Some helicopter types CAN loop - BK117, BO105 & Eurocopter Tiger (they are the three that I have seen).

Not all helicopters can loop due to the characteristics of their rotor systems. The beauty of the BO105 and BK117 is that their rotor systems are hingeless (or rigid for want of a better word). What this means is that they have no hinges to allow leading, lagging or flapping of the blades as they fly through the air. The blades themselves do these three functions. The beauty of this system is that they retain control power even down to -1g. To be precise, the BK117 and BO105 retains approx. 90% control power at -1g. What this means is that the rotor system has 90% ability to move into a new attitude at -1g. This is pretty good for a helicopter.

Down side - the ride can be a little bumpy but after the pilot becomes familiar with the flying characteristics - not too bad.

Enough of the Nerdy stuff. :8

[Thomas coupling]

T Richard: you have been extremely patient with us all, trying to expand your knowledge of helos. Whether some can do loops or rolls. Or is it mirrors and string technology?
Well I can honestly tell you that the real answer is:
somewhere up there in the clouds......................:uhoh:

[Gunship]

Lu Zuckerman To: Gunship


Please explain what hydraulics are used to effect lead and lag.




... Wise Owl ... do me a favour and explain ... the hang - over is killing me ..... :E

[Old Man Rotor]

Was the reference concerning gadgets such as the Hydraulic Dampers ......as on the S76???

[T_richard]

Thanks guys just what I was looking for. Now I gotta go find an airshow and see if it happens there. Very cool stuff even for and old fart like me

[PPRUNE FAN#1]

Why can't a helicopter loop? Certainly it's been done by helicopters with just about every head design extant. Back in the 1970's a chap named Mike Meager was a demo pilot for Enstrom and he used to loop the ship in his displays. (He used to do backwards touchdown autos too, which tells you something about his mental state.)

There are anecdotal stories galore of various military Bell 47's looping - albeit unintentionally. My father went through Navy flight school in the mid-1950's. He tells of looking up one day and seeing one of his squadron HTL's upside down. He thought he was witnessing a fatal crash, but the pilots pulled it out.

A friend of mine who began flying 206's when they first came out admits that he buzzed a friend's house. Being a lot faster than the 47 he had been flying, when he hauled back on the stick the nose went up past vertical. So he says he just kept pulling and it went over into a loop. B*llocks? This old guy was never known to exaggerate and he told the story very matter-of-factly and contritely, not in a bragging way.

Ray Prouty writes about the incredible power that the cyclic has in pitch, and how that power is not dependent on airspeed the way the elevator of a fixed-wing is. The problem of course is "keeping it positive." As long as you maintain a positive-G all through the maneuvre it should work fine. And a properly performed loop should not have any parts where you endure negative-G.

But there are other problems. In a 206, I'd worry about pulling the transmission deck fittings clean out of their mounts. I'd worry about clipping the tailboom upon entry. And of course I'd worry about the engine quitting right at the top of the loop. (Would you lower the collective? Raise it? Would it matter?) But an H-500? Man, I'd loop that baby all day long.

So......can a helicopter do a loop? Sure! Just as a hang-glider *could.* But would you want to? Errr, maybe not. It depends on a LOT of things.

[High Nr]

The S76 sim in West Palm Beach is great to play with. Until your half way around the roll. Then the lights all flash and the thing lurges and shakes as the the mild mouthed chap in the back shreeches something about his forced retirement plan , as we all sit there in the dark.

It was fun at the time.......

[PPRuNe Radar]

UK Army display team 'The Blue Eagles' have loops as part of the display. Aircraft type is a Lynx.

There are various example pictures on their website. This one is quite nice.

Lynx looping (http://www.deltaweb.co.uk/eagles/gallery/gall030.jpg)

There is also some video footage here, although the quality is not brilliant. The Lynx does a couple of loops in the sequence. File size is 1.2Megs.

http://www.deltaweb.co.uk/eagles/files/mildenhallsouthend01.rm

Edited as image was too big

[Buitenzorg]

PPRUNE FAN#1

"But an H-500? Man, I'd loop that baby all day long."

The scene: tropical isle, full of well-heeled tourists, spending dotcom dollars on helicopter rides. Mate works for one company, D and E models.

Chief pilot regularly loops (empty) ship, "just to show everyone who's the boss".

Then they have trouble balancing the main rotor, not a simple thing on a D anyway, but now it seems like nothing's working right. Until...

They pull the rotor head off and find cracks in 5 out of 7 straps in the strap pack. Some all the way through. Big "GULP" from chief pilot.

The chief pilot now uses the sign on his desk to show who's the boss.

[SASless]

Is the Lynx as unreliable as it is accused? Seems story after story is reported where it is described as being the holder of the worst availibilty rate of any UK military aircraft. Any truth to those accounts? What say ye who are in the know?

[T_richard]

Thank you for some very cool stuff, The video was better quality than I expected. They really do loop those things around. Great pictures I saved the one of the upside down Lynx.


Ya know, now that I think about it, I think your torque wrench has to be a few clicks away from a correct setting to roll a helio. I mean I am amazed that a/c didn't just fall out of the sky.

[BlenderPilot]

I really don't advise loops on any helicopter. The guys who do them regularly probably have the mechanics take the helicopter apart and inspect everything very carefully after a couple of those.

Buitenzorg
Strap packs on 500's break for many different reasons, also you are allowed to fly with a certain # of straps (can't remember how many) as long as they are not too many on the same side, and you don't need to pull the rotor head to find them you can almost see them from the ground.

I have only seen one helicopter loop and that was the MD900 Explorer, and they looked more like vertical ovals, the demo pilot did several here in the AeroExpo, and I was amazed at how slow he would do the whole thing, maybe started with about 50 kts, and finished the same.

I've seen video of a military S76 do a roll from level flight but the tail went all over the place and it looked sloppy not like airplanes.

Once to avoid a collision with another helicopter I pulled so hard on the cyclic of a 206, the aircraft went a little past vertical and slightly turning to the left fortunately I was going about 100 kts, and when the 206 was past vertical it must still have had about 70 kts. and I just kept back pressure until it first went slightly inverted pointing straight down and back to level waay past VNE, my passenger described the manuver as one of those little ribbons people pin on themselves to show solidarity for something. I had made a very odd 270 degree turn to the right. This happened out of pure stupidity and I wouldn't want it to happen again, I consider myself lucky and reborn after that.

http://homepage.mac.com/helipilot/PPRuNe/AS350Loop.jpg

[MightyGem]

Unless they've changed the display routine, the Lynx doesn't loop during the Blue Eagles display. What it does is a backflip. The pilot pulls up into a high hover, then pulls the cyclic smartly to the rear and the aircraft just flips over backwards, possible due to the semi rigid head design. :eek:

[PPRuNe Radar]

The Lynx currently doesn't feature in the Blue Eagles team due to operational commitments, however, in the last season when it appeared (2001 season) the routine included 2 loops and a backflip.

You can read reports on their official website.

http://www.deltaweb.co.uk/eagles/

[Flying Lawyer]

What MightyGem describes is the principle of the 'Flip' first performed by my friend Graham Waddington when he was the AAC Lynx display pilot.

This is how Graham described the manoeuvre to me:
The manoeuvre starts with a vertical climb using the Lynx's speed - care needed not to exceed 'G' limits on initial pull-up. As the airspeed decreases to zero, the aircraft is levelled maintaining high power.
Once stable in level attitude, but with a vertical climb, the pilot smartly pulls back the cyclic to the stop, and lowers the collective lever slightly to contain Nr. The Lynx flips smartly onto its back.
As the nose passes through the vertical, a forward push on the cyclic is required to continue the descent for display purposes.
During the manoeuvre the only time the Lynx gets near to its limits is during the initial pull-up.
The manoeuvre was fist displayed during the 1988 Blue Eagles season using a Lynx AH1.
Later in the season Graham practised with the then new Mark 7. With it's enhanced tail rotor authority, he was able to complete a 180 degree turn whilst upside down!

As the Mark 7 was new on the scene and in short supply, he never publicly displayed the 'Waddington Flip with 180 twist'.

The Lynx was able to do a normal loop, but as they only displayed with the Tow missile system fitted which caused a considerable drag, a lot of airspeed was lost during the inverted portion so that the aircraft had a tendency to fall out of the air!
Still recoverable but "not a nice polished performance".


Makes my gentle manoeuvres in the Gazelle seem a little wimpish. :*

[Hoverman]

Flying Lawyer
That's a name I haven't heard for some time.
Where is Graham now?

[CAC Runaway]

MightyGen is right the Blue Eagled do not currently loop the Lynx in the display. The backflip he describes is correct and the aircraft only loses about 200 feet. As to looping and requiring extra maintenance its not true (i have both looped and barrel rolled the Lynx). A properly flown loop can be done at 1g and will not stress the aircraft in any way. The head type does not matter too much either..the Gazelle will happily barrel roll and loop (although you have to be careful not to chop the tail with too much rear cyclic). Even a teetering rotor head system will loop as long as positive 'g' is maintained throughout.

[sycamore]

CAC-R
To take you to task-how do you perform a normal loop at 1g?
It is impossible to do even in a fixed-wing a/c with a pwr/wt ratio of >1:1 ,so what is your secret?And ,are you not flying the a/c outside its Release-to- Service Document?Aerobatic manoeuvres not permitted?What are the "g" limits on your Lynx? Do you have an approved accelerometer fitted?
I presume you have seen the "Westlands" publicity film of a Lynx doing carefully monitored rolls and loops,to demonstrate it`s agility, but I doubt it was ever cleared for Service use.Unless you can quote-?
I will agree that the Gazelle is pretty nimble,and as /one of the original project t/p`s for in-Service testing have probably been to more corners of the envelope,all I would say-a la Hill-Street- is-"Let`s be careful out there,boys and girls"!!

Syc../
:ok:

[BlenderPilot]

CAC-R

You talk about making loop as if it were the same as doing a practice auto, something relatively easy,

You stated:

"A properly flown loop can be done at 1g and will not stress the aircraft in any way. The head type does not matter too much either..the Gazelle will happily barrel roll and loop (although you have to be careful not to chop the tail with too much rear cyclic). Even a teetering rotor head system will loop as long as positive 'g' is maintained throughout."

In my very humble opinion the things you state on the above paragraph are misleading and largely incorrect.

Let me say I usually read a lot of things I usually don't agree with and let them go by, BUT in this case I am afraid some new guy or girl will read this and be mislead into thinking "its easy" and maybe go for it, so I feel it necessary to counterbalance your opinion.

So here,

I really doubt your average heli pilot could fly a "properly flown loop at 1 g", there are many reasons for this and I am sure some will be much better than me at explaining why this is very unlikely.

You said "The head type does not matter too much either" My humble opinion is that this is inaccurate, rotorhead type is what matters the most if you are going to attempt this, I am sure most sane pilots in this world wouldn't even consider performing a loop in an articulated or teetering head.

Then you state "even a teetering rotor head system will loop as long as positive 'g' is maintained throughout." do you have any idea how many things could go wrong here? My honest opinion is that if you get thru a loop in a teetering head heli, you got very lucky, and should consider yourself reborn.

I just really want to ask that when someone posts comments such as this, they do it responsibly, taking into account that the posters represent a small percentage of readers, there are a lot of new guys who only read this forum and rely on it for building their "descison making criteria"

Respectfully, BlenderPilot



LU-Z,

What Gunship was referring to in regards to "hydraulics, lead, lag" was probably the hydraulic dampers that control/restrict the lead lag in a lot of helicopters like the Agusta if I remember correctly.

[Ascend Charlie]

To correct a previous person's post, that CH53 did a BARREL ROLL, with positive g all the way. A slow roll is impossible in a helicopter (models do them OK, though) because you can't get negative pitch in flight.

And I am sure I have read previously that helicopters such as the Bell 206 are certified to +2.7g. This allows you to perform a level steep turn at 60 degrees of bank, where you must pull 2g to hold height, and be able to survive some turbulence while doing the turn, without the Jesus Nut popping off.

If anybody can perform a loop without pulling 3g or more, I would like to see it. Even in a clean jet like a Macchi, with plenty of airspeed, a 3g pullup still resulted in such a speed loss that the loop was more egg-shaped and you could barely hold 1g over the top. Doing a loop in a teetering head is just practising bleeding. I have come very close to inadvertently barrel-rolling a 206, and almost intentionally did it in a BK117, but the pucker valve over-rode my intentions. But the BK's aero demonstration is special.

Anybody who has seen the NH90 demo will certainly be awed- most spectacular thing I have ever seen by a chopper.:sad:

[cuzcurry]

I was fortunate enough to be in The Blue Eagles for a few years and have displayed the Lynx AH7 many times. Just for the record all of the manoeuvres flown were approved by the manufacturer and the MOD.

The last time I personally displayed it the more extreme parts were a loop which was entered at 120kts 600ft agl and completed purely in the pitch plane with no roll at all at the top of the loop. (That was Plan A anyway).

The backflip was flown from 600ft agl and was recoverable by 300ft agl quite easily.

The Eagle Roll was entered at 600ft 120kts and consisted of rolling the aircraft inverted and simultaneously turning through 270deg to the right.

The rearwards transition was flow at 60kts ending in a 90deg nose down attitude to fly away.

Other parts of the display include pedal turns which are broadly similar to a fixed wing hammerhead stall turn and wingovers which are almost identical to fixed wing wingovers.

By far the most difficult thing to do however was stopping the rotor blades at the same time as the Gazelles during the post display shutdown!

The short answer to your question is yes it can and has been done, the aircraft is not falling out of the loop, you are still definitely flying it. Incidentally the display aircraft were fitted with a G meter and all of the display was flown within the normal aircraft limitations. Flying this machine in the displays we did was without doubt tiring and demanding on the concentration front but also unquestionably the highlight of my flying career to date.

Hope this is of use to you. Feel free to e mail me if you would like further.



Thanks for your post and offer of further info.
Can I suggest questions/answers here on the forum instead of email so that we can all read and discuss.

Heliport

[CAC Runaway]

Thanks for that Cuz.... QED.

[Shawn Coyle]

Helicopters that I know of that have done aerobatics include the Apache, the UH-60 (one famous shot of Nick upside down in a Turkish model shortly after the US Army declared the Blackhawk was not cleared for anything more than 60 degrees of bank), the Rooivalk, Bo-105, CH-53, S-67 (old Sikorsky prototype that unfortunately crashed at Farnborough), Gazelle, Lynx.
At the speeds most helicopters are capable of, aerobatic maneuvers will resemble those of Cessna 152 Aerobat or other underpowered light airplanes (i.e. not like a Pitts Special)

[MightyGem]

Graham Waddindton left the UK 12-18 months(ish) ago for a job in the Bahrain/Oman region. Flying for one of the Royal families I think.

[Flying Lawyer]

Hoverman / MightyGem

Graham is flying in Dubai - and thoroughly enjoying himself.

[ShyTorque]

One manoeuvre I used to enjoy was a max power climb from the normal hover, increasing negative airspeed to around -ve 25 kts and retracting the landing gear. At 450-500 feet agl, the cyclic was moved sharply forwards, and the collective lowered to about half the previous setting.

The aircraft nosed very sharply over to 90 degrees nose down, by about 400 ft agl. Once fully vertical, full right cyclic (to the mechanical stop) and some right yaw pedal rolled the aircraft 180 degrees whilst maintaing the 90 degrees nose down descent. It was then just a matter of a natural easing out of the dive, on the reciprocal heading, to level flight at about 50 agl and 120 kts.

Unfortunately it was latter banned as another display pilot (well two others actually, on separate occasions) managed to get the tail rotor blades to hit the inclined tail structure, even though when the blade hinges hit their stops there should have been about 12 inches of clearance from blade tip to hull!

[Triple Matched TQ]

Was that in the Puma ?

[avlerx]

Did the Uk Army display the Westland Scout and if so what was in the program.

[ratsarrse]

I thought I'd seen a Lynx do a loop somewhere back when I was still at school. I'd dismissed it as a hallucination, or false memory syndrome, but know I know it might just be true - thanks guys! Now, where did I see this happen? Or was it just on TV? I wish my memory was better.

[the wizard of auz]

I once managed some spectacular aero's in a R22 once.
I was trying to hover during my very first time at the controls :D :}
Sorry Dave, I hope your over the initial shock and will let me try again mate, gotta finish this damn licence ya know. ;) (and I know ya reading this)

[Fair Flair]

Hi Heli Aerobatic fans.

Just a little more info for the pot.

I co piloted for Mike Meger, Enstrom test pilot in the 70's for the world championships in 1973. He won the freestyle event. (PFM won't allow the routine to be called - aerobatics) He took me through the handling so I was able to display a semi aero routine at Farnborough 1974- 1980.

Since then I've completed the same display on Enstrom 280, Hughes 300, Hughs/MD 500 and Enstrom 480. I'm up to 378 public displays, plus as many practices. Every three years or so a World Freestyle championships is held, but it is always a little publicised, little attended event. I've been placed 5th, 1st and a most recent third at the eleventh championships in Austria last year. I feel if the Lynx boys had been allowed to take part, a military first place would have been achieved every year. Q Smith has won this event and a Japanese pilot took the 2002 title on a R22 !! But a fine display.

The real master was of course, Charlie Zimmerman - the German who won the event in two consecutive events using the fixed head B105. A phenomenal display routine.

All the types I fly can be looped and the handling I use on the Enstrom is as follows.

Up to 100 knots S & L, with aft cyclic, although translational flap back also brings the nose up. At the 90 degree point with the disc level and at 70 knots, firm aft cyclic looking over the shoulder for the horizon to come round. At 60 knots, lever is going down and providing the disc is still held level AND a minimum of 40 knots is on the dial, aft cyclic can be maintained to pull through to the descent with lever still being down. As the vertical is passed speed will build to 60 knots which is monitored with cyclic and raised lever. The S & L attitude is usually reached at the entry speed of 100 knots.

This routine is only adviseable over 1000 feet, since any speed error results in considerable height loss. Being a small helicopter, my full display is performed at 400 feet for an effective show. I have 'split the needles' with too much down lever when inverted, but overall all my manoeuvres have been observed by Enstrom flight test department and considered safe. On a personal basis, I have flown the full routine with an eight inch balsa wood dorsal fin extension to check on blade travel and tell tale markings on M/R dampers, so I am happy to go on displaying until the doc tells me to stop !

Mott Stanchfield in Florida flew my routine a few good years before me and quite a few other 'nutty pilots' also enjoy showing off the capabilities of the various articulated head marques.

A final note. Please don't try this at home without some guidance.

Good flying out there.

Rotorboy.

[PPRUNE FAN#1]

Nice post, Rotorboi :)

If you were to ask most helicopter pilots what the technique would be to perform a loop, they'd probably recite that for a fixed-wing: dive for as much airspeed as you can get and then pull, pull, pull. But most helicopter pilots also probably misunderstand just how much pitch power the cyclic has. Rotorboy ("Fair Flair") tells us that he started his loop from straight and level flight!

And if an Angst-rom...sorry, Enstrom can be looped from 100 knots S&L, imagine the loop a 206 could do! (Uhh, if the deck fittings kept the transmission attached to the airframe, that is.)

Granted, a helicopter loop will probably not be symmetrically-shaped like that of an airplane, but hey- a loop's a loop.

I never saw Mott or Mike Meager or Rotorboy do their routine, but I've heard from those who have that it is awesome to see a helicopter doing what we've always assumed was "impossible."

I understand Nick is working on a Comanche airshow routine with a maneuvre called the "hover roll." Reportedly, he's gotten it to work, but the downside is that is uses up an hellacious amount of altitude ;)

[Blue Rotor Ronin]

positive pitch. easy.

[B47]

I am about to get a display authorisation for my B47 and keen to do a few Northern airshows next year. Got the provisional DA number and fully digested CAP 403, but now giving thought to the actual display routine.

Anyone done any display flying and have any advice for a newbee?

It would also be good to hear opinions on what constitutes a good display.

Leaving aside 'edge of envelope' aeros in Gazelles and Lynx's and the fantastic display of personal skill by Dennis Kenyon, how do you think a classic (and precious) Bell 47 should be displayed?

[Ascend Charlie]

It's a bit hard to make a 47 display look interesting, when the difference between a high-speed pass and a low-speed pass is only 30 knots!

Whatever you choose to do, start with each segment by itself and practice, practice, practice. There are plenty of display pilots in the ground because they attempted something they had not practiced - an impromptu display. "It seemed like a good idea at the time."

Torque turns look good when well done, and a hovering "waltz" done downwind shows off some manoeuverability. Doing it downwind gives you a bit more tail rotor authority.

Somebody with more 47 time than me could tell you what to do, but in a Huey for a short display, we would fly in at 100 kt at 50' downwind along the crowd line, pull up into a torque turn, recover from that around 100' back into wind about 80 kt, pull around into a tight descending 360 to do a skidding landing to stop in front of the crowd. Pull up vertically and allow the tail to turn through 360 as you go. Nose down, pull around in another descending turn to finish in a hover at about 30'. Hoist one person down to the ground, recover the cable. Bow to the crowd, pull the nose up, pedal turn 180, depart downwind.

A reasonable amount of action, and the only time the crowd loses interest is while the cable is being winched back up.:p

[The Nr Fairy]

B47:

Check also DASC Display Flying Notes (http://www.dasc.mod.uk/HTML/Display-Flying-Notes/dfn-contents.htm).

[Helinut]

Try talking to other B47 pilots who have done display flying. There was a lady pilot who had a B47 she used to display (G-MASH). Not seen her lately, but she may still be around the bazaars.

[Zlin526]

Ring up those awfully nice chaps in the CAA Air Display section. Every time I've had dealings with them, they've been very helpful..Very un-CAA like.

As Tim Nice-but-Dim would say, "Awfully, bloody nice blokes"

Zzzzzz526

[KENNYR]

Try and get in touch with a fellow by the name of Al Gwilt. He displayed the sioux with the Army Air Corps and should be a goldmine of information for you.

I last heard of him at [email protected] or try 01708-688115.

[DBChopper]

I believe the lady pilot in G-MASH who Helinut refers to is Tracy Martin who displayed at Aerofair earlier this year. I think she may have been based at Redhill... Not sure if she's a PPRuNer. Great display.

[PPRUNE FAN#1]

B47 asked:Leaving aside 'edge of envelope' aeros in Gazelles and Lynx's and the fantastic display of personal skill by Dennis Kenyon, how do you think a classic (and precious) Bell 47 should be displayed?Static.

[Vfrpilotpb]

Take us all back to early life, get two people in the bubble , dress on like PT and the other like Chuck, get some big rubber floats , and Hey, instant nostalgia, whatever else you do you caught the attention of most of the older guys!!;)

[Heliport]

Is this what you had in mind Vfrpb?

http://cellmath.med.utoronto.ca/B47/history/wbGuide/pix/HillTobey_01.jpg

http://cellmath.med.utoronto.ca/B47/history/wbGuide/pix/wbCover.jpg

[Vfrpilotpb]

Heliport your a Star, next to Neville Duke these two guys were my boyhood Hero's, always wanted to do their job, sad really finished up pushin big rigs around Europe!!:{ :{

[Rich Lee]

I, for one, am always excited to see older aircraft flying at airshows rather than sitting in the static area. I have always stopped to watch whenever G-MASH does a flyby because it is history. Good luck to you!

Here are a few general tips I have learned over the years about helicopter flying displays:

1. Restrict your display to no more than 5 minutes. It is better to leave them wanting more than having them walk away because they have seen too much.

2. If you are repeating any maneuver more than twice the routine you are flying is probably too long.

3. Use smoke if possible. Smoke adds to visibility to a small and relatively quiet aircraft. Smoke in a maneuver like a vertical auto when it boils around the rotor can be very exciting.

4. Center your show but do not forget to work the lateral limits of the show line. Plan at least one maneuver at the far left, far right and at the center of the show box. Many people forget the cheap seats in favor of the VIP's-please do not be one.

5. Use music and time your maneuvers to coincide with the music where possible.

6. Do not spend a lot of time hovering unless you are picking something up, putting something down or posing for photographs. Where possible keep moving and always move in three dimensions.

7. Associate your display with a theme (MASH, Whirlybirds, Blue Thunder, Flying Farmer or whatever tickles your fancy)

8. Never, ever dust off the spectators with rotor wash. Doing so is extremely poor form.

9. Never do anything your aircraft is not safely capable of doing.

10. Commit your routine to paper, practice your routine until it can be performed on a subconscious level, and never deviate (add or subtract) from what you have practiced.

11. Cancel a display when you feel bad, the aircraft is not perfect, the weather is uncooperative, or the planets aren't aligned correctly. Never continue because you don't want to let down your sponsors, the show, or the people.

12. Calculate and be aware of turning radius, scatter distance, and performance for each venue.

Heliport-Thanks for the Whirlybirds photographs. Awesome! I love those guys (in a manly sort of way of course!).

[VeeAny]

B47

Check your PMs

Cheers


VeeAny

[Rich Lee]

http://www.newwhirlybirds.com/

[greenarrow]

Give Al Gwilt a call he will help where he can and he is still in practise with the 47.
Numbers above are good.;)

[B47]

Thanks everyone very much for some great advice and apologies for the delay - I've been away.

Tracy Martin (G-MASH) has been very helpful - we're planning to meet soon and I'll follow up all the other contacts.

Will keep you posted!

Ta.


:ok:

[NickLappos]

Having flown displays at several dozen airshows, including Paris in front of 125,000 people (it was something I will never forget!!)let me chime in:

1) Do only comfortable maneuvers. A maneuver that takes the aircraft to 90% of its limit and a maneuver that rips the guts out of the machine look about the same to the crowd. Don't kill yourself for that extra 10%.

2) Do what helos do, it is simply amazing enough to sell itself. Go straight up, make pedal turns while doing so. Stop dead. Go sidewards. They see all the airplane stuff, show them what we do that is different.

3) Make every show just like the last one, and make them all like the one you practice. The way to tell a show pilot from a cowboy is the consistancy and practice.

4) Never go toward the crowd, ever. Never bust the show line, or the show box, ever.

5) Have fun.

[Hoss-Fly]

Howdy all,
When I was in army flight school, I saw a video of specially modified Apache and Blackhawk doing loops and rolls. I have also seen on Wings Discovery Channel a few other birds really tearing up the sky. What helicopters are capable of aerobatic manuevers? What are the design considerations? And the most important aspect, pilot technique? The reason I ask is because whenever this army thing gets old for me, I want to get a helicopter and do airshows. I know it would be easier to get a Pitts and do it, but I just like helicopters to much to turn on them (my Blackhawk saved my #ss several times in Iraq...908, what a bad #ss bird!). Thanks for you input, have a great day.

Fly Army,

Vince Rodgers

[Rich Lee]

For the record, neither the AH-64A nor AH-64D Apaches used for aerial display are, or ever were, specially modified. No unusual loads are experienced during the displays. No special or display unique maintenance is required after performing a display.

Every helicopter flying has some aerobatic ability. In some helicopters small deviations from limits are fatal.

[NickLappos]

Rich,

I can say the same for the aerobatic flights in the Black Hawk and Fantail demonstrator, since I flew some of those scenes.

It doesn't take modification to fly aerobatics in a modern, high control power helicopter (like a Boelkow, Black Hawk, Apache or Comanche) but it does take reasonably special knowledge. If you mess the maneuver up, you could really cause problems for yourself or the machine, including rotor head damage, blade strikes on the airframe, or sudden meetings with the ground.

In short, those maneuvers are great for Discovery Channel shows or magazine covers, but they are of little use tactically, and leave little margin for error. Like the small print at the bottom of the car ads when the family sedan is shown rat-racing down the walls of the Grand Canyon, "Professional drivers on closed course. Do not try this at home."

[Heliport]

Hoss
Welcome to the forum.
You may have missed these pictures which appeared earlier this year.

http://www.helicopterservice.com.au/photos/pprune/crash%2001/99-372-002%20small.jpg

http://www.helicopterservice.com.au/photos/pprune/crash%2001/99-372-014%20small.jpg


If anyone has any pics of the Black Hawk and Fantail demonstrator in similar mode, please post them.
Anyone at all ............ Nick? ;)

[Autorotate]

Nick - Whatever happened to the Cheyenne as I saw some old videos of it and it was an amazing looking aircraft.

Autorotate.

[Lowlevldevl]

I seem to remember that the Cheyenne, plus some other exotic 'one-off's' were destroyed in a fire at a helicopter museum somewhere.
Nick, True or False?

This thread confirms my worst suspicions, 8500 hrs in a Hughes 300 and never looped or rolled it. I MUST be a chicken.;)

[Hoss-Fly]

lowlevl,
I'm at Fort Rucker now, going through the IP course, and at the museum is a Cheyenne sitting out near the parking lot. Though they put a fresh coat of paint on her, she is corroding badly. Sad site.

Fly Army,

Vince Rodgers

Heliport, thanks for the photos, those are awesome.

Mr. Lappos and Mr. Lee, thanks for your advice, I know that you guys have thousands of hours and experience to what you say.

Mr. Lee and Mr. Lappos, what civil helicopters do you all believe would be a good aerobatic demonstrator? I won't try this stuff in an army ship, as they would really be pissed! But I really am serious about getting into the airshow arena. Though, this will all have to wait a while as I am currently in the IP course and about to head off to Europe. Thanks and have a great day.

Fly Army,

Vince Rodgers

PS. How do you guys like test flying? I have 15 years to go to retirement and I can't see myself just being a Blackhawk driver for that entire time, I would like to contribute to another area when I have more experience. Though my degree is not in engineering, I have started working on my Masters in Aeronautics (Embry-Riddle) and am looking at also taking some college math courses to see if it's suitable to me.

[SilsoeSid]

Mid 90's I was involved in getting a photograph of a GazelleAH1 inverted with a backdrop of the White Horse at Sutton Bank N.Yorkshire.
After MANY attempts the final photo is a pearler.
I don't have a copy myself that I can locate, but know a man who does and will try and post it.

In answer to the original question a helicopter cant 'fly' upside down as in FW speak. If you were to maintain the attitude, the last thing to go through your mind would be a white nav light!

Its like saying you can jump to the moon, but in reality you can only manage to go about a foot and a half !

Cheers, SS

[221B]

Here are a couple of clips taken from an R44 while flying the London Heli-Lanes (thanks to SteveR for hosting them):

Shots of London following the heli-lane along the Thames from East to West, Millenium Dome to the Battersea Heliport (39Mb): London (http://beast.gxn.net/spr/videos/london.mpg)

Shots of Heathrow following the heli-lane South to North (24Mb): Heathrow (http://beast.gxn.net/spr/videos/heathrow.mpg)

A bit of fun (39Mb): ateam (http://beast.gxn.net/spr/videos/ateam.mpg)

Updated version of the ateam vid which should be more compatible with most systems (and only 16Mb): a-team (http://beast.gxn.net/spr/videos/a-team.mpg)

Thanks also to rotorcraig for various bits of the flying and camera work (but not at the same time!). He is also responsible for the A-Team idea. I take no responsibility for anything.

[overpitched]

I saw, very briefly, on the tv the other night a helicopter doing what appeared to be a high speed low level pass down the Brisbane River with the skids actually skipping along the water.

The stunt was performed as part of World Expo 88 and I was curious to know if anyone can tell me who performed it and how it was done etc.

[Apollo 100]

I did a pairs display in a B206 for Expo 88 along the Brisbane river, but I don't remember dragging the skids along the water! (at least not that I knew about! ) Was it a B206 that you saw on the video? More memorable for me was a night display which I did for the FM104 skyshow in Bne a year later (don't try this at home kids) anyone who performs stunts at night must need their head tested....!

Apollo:}

[Heliport]

Apollo100

Have you got, or can you get, any pictures of your exploits?

Heliport

[Apollo 100]

I'm in danger of giving away my identity here! but what the hell! Most of my earlier antics at helicopter display flying were in the pre-digital age and the only records I have are your average glossy print taken by my faithful wife. In later years I performed as part of the Blue Eagles display team (i've done it now!) an there are a number of photo's available on their website including one or two when I was in the team. Anyone who went to Fairford in '93 (famous for the mid air of 2 x Mig 29's) will hopefully remember quite an impressive display by our team. While I'm on the subject - any of my old team pals reading this send me a PM, be good to know where you are now.

Apollo

Overpitched: In answer to your original question I do remember now who performed the particular stunt that you are referring to. A guy call Ross Rundle. He was in my opinion one of the most skillful helicopter pilots I have ever come across, and to answer your question as to how he did it? illegally for one! but he had such fine control of his aircraft that he got away with it. Those living in QLD in the mid - late 80's may have seen him perform his solo "snoopy" routine, with a piece of rope attached to the skid and a loyal assistant on the ground, great entertainment, don't know if anything like that still goes on. For my German collegues the greatest helicopter display pilot probably the world ever saw was the late Capt Charlie Zimmerman, saw his display in a BO 105 in Hanover many years ago, quite unbelievable. I'd be intersested to know if helicopter displaying is still alive and kicking. There used to be some great teams (RN Sharks, Grasshoppers etc) and some great parties!

[overpitched]

Apollo

Thanks for that. On the quick clip I saw it looked like he was doing quite a good speed as there seemed to be a lot of water flying around and the skids looked like they were actually skipping along the water. Do you remember what speed the stunt was performed at ??

I would love to get some decent footage of it as the tiny clip I saw looked very impressive

[deeper]

Overpitched,

Actually the helicopter went a bit close to the water and the vertical tail fin or the rear of the skid did touch the suface.

It was a Kiowa from memory and it was very close to going in.

I have a video of a night aerobatics display in an aeroplane it is quite spectacular.

Deeper.

[Apollo 100]

Overpitched: Deeper is absolutely correct about it being a Kiowa (B206 B1) and it was most likely the stinger (the bar underneath the tailrotor) which probably went in the water a probably throwing up water into the tailrotor causing the spray. Couldn't be sure without seeing the video though. Hard to say what speed, I only vaguely remember it but I imagine about 60kts would probably be in the ballpark. Doing a stunt like that was not smart - nor a good example to more inexperienced pilots. There is a very good rule in display flying - your show should be as safe as houses whilst giving the illusion to the crowd that it is dangerous! In the UK your display is scrutinised before you are allowed to perform in public - any hint of a dangerous routine and "no show" :sad:

[overpitched]

From what I saw it was definately in the "don't try this at home folks" category

[Jacques Stahl]

Hey Apollo,

I didn't realise Charlie Zimmerman was dead - you are right, his displays were awesome. I still have a set of his wings which we swapped at a Heli-meet in UK in the eighties.

Those were the days!:ok:[B]

[Apollo 100]

Charlie was one the the nicest guys you could ever meet. He was very modest about his amazing skills with a BO 105. I was told by someone (I think at an airshow in Berlin in 1992), but can't remember who, that he was killed in an accident. Can't verify that though. I hope it is not true but I fear it is.

[sycamore]

Reminds me of a time(39 yrs) when we used to dabble the nose-wheels of our trusty Whirlwinds(S-55) in the surf at 90 kts on the long beaches in Borneo. The crewman in the door would usually get wet.......As you got lower , there was a reflected swishing noise from the rotors, which would increase in pitch the closer you flew to the surface.....probably Doppler frequency shift....but it allowed you to judge contact very precisely!!!!

And then, we did it at night.................!!, until we came back with a fishermans` mist net wrapped around the wheels.......!!!

However,that was then, this is now ,and I would never condone 20yr old helo pilots doing such a thing!!!!:ok:

[Vfrpilotpb]

At a CAA safety meet about 2 years ago, a video was shown of a pilot who was flying an R22 behind a speedboat and he appeared to try and dip his skids into the pond, what seems like three frames later the same pilot was breaking the surface gasping for breath, Neptune grabbed him within the blink of an eye!

[SilsoeSid]

Sorry for the delay, I said I would post here, but not when! I first posted this in the 'rotorheads gallery'

Sutton Bank, North Yorkshire.

http://i52.photobucket.com/albums/g11/silsoesid/GazelleSuttonBank.jpg



edited to re-insert the pic as the link was lost.

[Aser]

Just to add wood to the fire... :E

Loops and rolls in a CH-53

http://www.augustoheli.com/videos/videoarchive/FullScale/CH_53_RollLoop.zip

[nickel]

Hi all,

Ok, maybe the maneuver I will ask about doesn't have any practical use but still...

I have looked at 360 degree loop videos like http://youtube.com/watch?v=53y8An1zAsc or for a Ch53 http://youtube.com/watch?v=VC2E8RJE3Jo .

I am curious if it is possible to make such a loop from hover (from 0 initial speed case). If you would pull the stick back fully it would create a continous torque on the rotor and this should result in a turn. You would loose altitude pretty fast but assuming the starting altitude is high enough it should be makeable.

It would look cool if you are trying to show off! I, however, don't remember seeing such a thing. Is it just too dangerous or simply impossible? What would happen if you try this?

[RVDT]

Do you mean like this? http://www.youtube.com/watch?v=wIiFmHfdg-c
It is not a circular loop but is 360 deg of course.

[mountjoy]

I think its called a 'shuttlecock' saw a lynx do it at farnborough last year. From a standstill to following in lie/formation with 3/4 gazelles.

MJ

[nickel]

RVDT: Yes that's what I meant exactly. I somehow failed to find a video like this and was trying to figure out why it can't be done :) Thanks for the video the maneuver looks cool.

[wg13_dummy]

The Lynx carries out a manoeuvre called the 'Back Flip'. From the hover, it rotates pretty much around the tail rotor, vertically through 360 degrees. One of the advantages of a semi-rigid rotor head. ;)

[nickel]

wg13_dummy: Why is it an advantage of semi-rigid rotor head? Shouldn't other rotor heads be able to do the same given enough power?

[wg13_dummy]

Yes, but you have less chance of chopping your own tail off with a semi rigid arrangement. ;)

[somepitch]

i don't know about that! the semi-rigid head is the "teetering" head found on bells and the like...i think they'd do a fairly good job of de-booming a machine performing aerobatics. i think you're referring to a fully rigid head such as the 105 and lynx have :}

[wg13_dummy]

The Lynx has a semi rigid head. The Bell teetering head is not really concidered a semi rigid in the true sense of the word. The Lynx uses the flexing properties of the Titanium head in lieu of hinges.

[spinwing]

Mmmmm ....

Well Karl Zimmermann was awarded an FAI Gold Rotorcraft Medal award in 1993 so I assume he was alive for that!

However I believe it was Ziggy Hoffmann who was killed in a Bo105 whilst doing some filmwork in the USA .... though can't remember when ???

I am of course ready to be corrected ... :eek: ...'twas such a long time ago.


Cheers :E

[Big Bucks Bernie]

According to this thread (http://www.pprune.org/forums/showthread.php?t=169597&pp=15), the fatal accident involving Ziggy Hoffmann happened on September 20, 1989 in Tuckerton, NJ (see NTSB Report (http://www.ntsb.gov/ntsb/brief.asp?ev_id=20001213X29473&key=1)).

[somepitch]

The Lynx has a semi rigid head. The Bell teetering head is not really concidered a semi rigid in the true sense of the word. The Lynx uses the flexing properties of the Titanium head in lieu of hinges.


in every book i've ever read, and after googling "semi-rigid rotor head", i have always found that the terms teetering head and semi-rigid head are interchangeable, and that rigid heads do not use hinges for flapping or lead/lag, instead relying on the flex of the head/blades...

[wg13_dummy]

Like I said, I couldn't comment on what the Bell teetering head is as I only have experience of Bell 47's. I do know for sure that the Lynx has a semi-rigid arrangement. If not, I've been teaching it wrong for 15 years.

I know one thing for sure, I wouldn't try and back flip a Sioux!

[somepitch]

haha i'll second that one!

didn't mean to seem argumentative btw, i've just learned slightly differing terminology :}

[wg13_dummy]

Absoloutley. As GBS once said; "England and America are two countries separated by a common language." ;)

[DennisK]

Display Flying & Aeros

Ref the notes on Zimmerman & Hoffman ... both these guys helped me develop my display routine. I first flew with Zig Hoffman at the 1974 Farnborough show. I was demonstating the standard Enstrom 280 Shark and Hoffman and I swapped practice sorties as co-pilot. His BO 105 display included the first full loop I had seen. His machine was fitted with a rearward reading ASI which he used for his backward spiral climb. I copied his manoeuvre which has been part of my standard display routine for thirty-three years.

I flew with Charlie Zimmerman during the practice for the Cranfield World Championship in 1986. He was able to invert the BO105 at 1250 feet, with the lever full down and right yaw pedal, maintaining the inverted spin down to 500 feet before rolling to level flight as he stopped the spin to exit the manoeuvre..

Charlie had won the previous two events, but the 86 title was won by Hermann Fuchs with an almost identical display routine in the second team 105. At the 'apres ski' drinks later, the German team presented me with one of their display plaques which still adorns my study wall.

That year, Andy Berryman made a fourth place in the Army Gazelle. Anyone know if he is still a flyer?

I was taught the 'trade' by the Middle Wallop 1973 World Championship winner, Mike Meger, and a little later by another Enstrom test pilot, Mott Stanchfield.

Like our fixed wing cousins, my view is that 'display flying' does add a differing dimension to our industry. In my case, my early Enstrom displays at Farnborough and Paris certainly put a 'much criticised' type on the map. By today's Robinson standards, my sales weren't all that good, but I did personally make the sale of 138 Enstrom models while working for that wonderful entrepreneur, Roy Spooner.

Yes, of course there is an extra risk element, but display pilots are checked carefullly by a CAA appointed DAE, (display evaluator) and when, as occasionally happens to me, I am approached by a high time pilot, and advised I won't be lasting too long in the industry, I have to mention that the routine he had just witnessed was the 1205th (on the last occasion) public display I have flown, and save for a severed T/R cable at the 1999 Biggin Hill show, (non damaging landing though) I had not experienced any problems or ever damaged a machine.

I think I have said before on this forum, I'd dearly love to see a couple of suitably experienced youngsters take over from me (total retirement looms!) and work up a 'duo' display routine. I could run a two ship team, offer say a sixty display per year programme including all aspects and costs of the operation for around £350k a year. Any interested sponsors out there?

Best wishes to all,

Dennis K

[Gaseous]

What sort of experience is 'suitable' Dennis?
I've got a bit of Enstrom time and own and fly the last 28A you sold. G-BDKD no 319. A beautiful machine.

It would be a travesty if your display skills are not passed on.

[DennisK]

For Gaseous ... Not sure about the 'travesty' bit, but I do want to see some other pilots arrive on the heli aeros display scene. I've provided a few DAs to interested youngsters, but as far as I am aware, only one has actually displayed in public. A pity.

What is suitable experience? ... a moving feast for sure. But overall the budding display pilots needs - and in order.

1. The right temperament.
2. Plenty of type experience other than S & L work. Say 500 to 1000 hours, but those numbers shouldn't be set in rock.
3. Previous aerobatic experience in fixed wing. Pitts, Extra, Edge types.
4. The right temperament.

I'd be happy to offer an 'informal' course, but the trainee needs to provide the machine, with associated insurance for the role flying.

I use only twelve basic manoeuvres in my display sequence, so around twelve hours total should bring a competent pilot up to public display standard. I'm booked for a dozen shows this year, but can't see myself flying beyond the 2008 World Champs event. (I'm 75 this Oct !!!)

Regards to all,

Dennis Kenyon.

[Hoveronly]

I had just arrived in my first Squadron in Germany and was out on a recce near Minden when we came across a 105 which was being thrown around. The German Army pilot saw me too and obviously wanted to play. We came nose to nose and ended up with him flying at about 50 kts rearwards when he just flicked it over backwards and dissapeared beneath me - really cool! :cool: And all at lowish level as well!

I have an old video of Zimmerman display training at Buckeburg which I liberated from the ECD Eurocopter factory a few years ago! Even when I see it, I still cant believe what he got up to !