r22 rollover
 

From the Ananova news website:
Two escape as frost downs helicopter
Two men have narrowly escaped injury after a helicopter toppled over on take-off because part of its undercarriage was frozen to the ground.
The privately-owned R22 helicopter was attempting to take-off from Gamston, Nottingham.

A spokeswoman for Nottinghamshire Police says the two occupants were not seriously injured, but one was taken to Bassetlaw District General Hospital, suffering from shock.

The spokeswoman said: "In trying to take off one of the helicopter pads was frozen to the ground. This caused the helicopter to topple over. There are no serious injuries to the two men inside."

Fire crews went to the scene and air investigators informed, the spokeswoman added.

The Robinson POH addresses Dynamic Rollover and tells the pilot what to do in order to counter this condition. That countermeasure is to dump collective when the pilot becomes aware that he is in that condition. I can see it now, Robinson will ammend Safety Notice SN-9 to tell the pilot to check for freezing of the skids to the ground and add a new piece of kit to the helicopter support equipment. An M1A1 MkI Ice pick.

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The Cat

Well, if he does it will be due to litigation gone mad on your side of the pond (and coming this way too).

Another company in my neck of the woods recently had a B206 thrash itself (and the pilot) to death before falling off the edge of the platform. The cause? the pilot forgot to check that all 3 tie downs were removed, it only takes one. Can't see Bell adding that to the FM though, some things just have to be left to airmanship.

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Another day in paradise

The Robinson POH advice on DR (and the safety
course material for that matter) is good, as far as it goes.

Trouble is that it might channel thought in one direction only, ie. when drift is allowed during take off or landing.

When a skid is frozen to the ground or obstructed the hapless Pilot may be pulling increasing amounts of collective, wondering why it feels so heavy and the WHACK! It's all over for the little beast(hopefully the occupants will not be injured).

The Heli. must act a little like a taut catapult. Whatever holds the skid lets go and in a very short time......

In reaction to this occurrence I have written
some advice for Pilots to take BEFORE any take off is attempted. It will go into my version 2 website (to be online from Xmas)
and I would appreciate you opinion(s) on it.

Follows-


A Helicopter may be landed on a frozen surface without the Pilot being aware of the danger that awaits. Latent heat from a skid or wheel may melt ice on the surface which can refreeze shortly afterward. It can be very strongly bonded to the surface. Dynamic can end the next (very short) flight. Check that skids or wheels are free before attempting to take off. Use a lever if you have to (it can be done with a length of timber in preference to metal which may cause damage).

For an R22 Pilot the initial check is easy to perform, no lever required. Gently pull down on the tail in the same way as you would check the TR gearbox oil level. If the front of the skids lift readily then it is less likely (but not impossible) that the heels are stuck. If there is any resistance don't hang from the tail but be suspicious and move on to the lever check. (It is unlikely that the heels of the skids would 'dig in' to a grass surface by lowering the tail as it is harder when frozen but use your judgement.)

Regards
SPS

Or, how about a winterization kit that ducts the engine exhaust through the skids?

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The Cat

Lu, perhaps not a good idea if you land on snow or ice. The aircraft will sink further in, then really freeze in and be there till next spring comes.

[This message has been edited by ShyTorque (edited 17 December 2000).]

To: Shy Torque

That's true, but there would be one less R22.

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The Cat

I truly hope you are trying to joke Lu, no mod is necessary, no POH amendment is necessary. Proper pre-flight is required (assuming the stated cause is correct).

And you don't have to dump collective as long as you performed your proper pre-flight preparations and were paying attention.

Maybe this is the "C"CFI's way of grounding the machine!

As one of the most important parts of the pre flight check is to pull down the tail and check the tail rotor gearbox level, hopefully this should catch this problem as described above.. Whereas we are very aware from training of the need not to have any sideways drift as you lift off, if both skids were frozen down you would not realise until the thing came unstuck with a great leap into the air. Nasty!

Very funny.

Just be mindful of this -

(A)Every time a robbie 'falls over' the potential exists for someone to lose their life. All lives are worth the same.

(B) Every time it happens the whole industry is damaged, not just a small helicopter that attracts ridicule from the industry's upper strata.

(C)Public perception of Helicopters in general and the industry as a whole needs to be improved. Every accident counts on the public scoreboard, whether it involves an R22 or a V22. The public make no distinction. A Helicopter is a Helicopter and that is that.

(D)Everyone in the industry should (could) be pulling in the same direction, whether a lowly 'C' cat (which I am proud to be)or the highest powered cat.

I'll carry on doing what I can to improve things and leave this with you.

My initial post was placed not in response to the story about the problem of a frozen skid but to a post placed by Helidrvr regarding Occams Razor which stated that Robinson shifts the responsibility to the pilot in order to absolve themselves from responsibility.

I added the Icepick as a bit of humor. When the post was made about the latent heat of the skids or wheels causing the snow or ice to melt and refreeze I ,with a bit of humor posted the thing about the Exhaust being ducted through the skids. Another post was made about the helicopter being frozen til spring. I assumed that that post was made also in humor and I made my response about one less Robbie.

If you look at my bio and have read my posts you will have noted that I support aviation safety. I once knew a guy that was crewing a Hiller H-23. They had just Dropped the Governor of Mass. on a roof top landing platform and when they took off the APU was still connected. The helicopter tipped and fell about 20 feet. the blades hit the ground and the stub of one blade flexed down and seriously damaged my friend in the area of his chest and arm pit.

I think on my following posts I should indicate what is fact and what is posted in humor.

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The Cat

Pleased that the pilot and pax weren't injured. It must have been a terrifying experience.
A lesson (or reminder) to us all.

Lu
You've livened up this forum. Well done.
One small request, try to resist the temptation to use every topic to make anti Robinson remarks!

To: Hoverman

Truth be told, I think that the Robinson helicopters are quite good helicopters for what they can do. My problem is that I feel that the restrictions placed on them by the POHs makes them uncertifiable because they can't meet the FAA requirements to demonstrate sideslip and out of trim flight. It is not to say that they can't do these things it is that they are restricted from doing them (see Helidrvrs' post on Occams' Razor somewhere on this forum).

My major thrust in writing my report was to get Robinson to go to a three bladed rotor system. I even offered a design for the system that would use their existing blades.

The three blade system would incorporate offset hinges that would allow lead lag and flapping. Even if they were not to use this design the three blade system would offer a larger cg travel and at the same time eliminate the problems of zero G and most of all the problems related to the 18-degree offset would go away.

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The Cat

[This message has been edited by Lu Zuckerman (edited 17 December 2000).]

With regard to the original thread of the Robbo accident..........

The aircraft was located at a private house some 800m from the airfield boundary at Gamston and had remained on the ground all night prior to attempting its ill fated depature.

As we were the first emergency service allocated to the incident, I find it very surprising (or not in the case of a PPL pilot, no disrespect intended!) that the pilot had not phoned or called Gamston to inform them of his intention to depart within the ATZ. Do we still teach airmanship these days?

Additionally, on informing D&D,(we did this enroute) they contacted Gamston who denied any knowledge of any such incident, therefore degrading the response of SAR.

So it was with much confusion that we actually located the incident. Fortunately, both occupants only suffered minor injuries and the aircraft had actually bounced back onto its skids after suffering the roll over, therefore minimising any spillage of fuel etc. However, I don't expect there will be much change out of 60k for the repair bill!

I was a little disappointed by the response of the pilot to one of the paramedics who stated that it was all a fuss about nothing.

However, I'll put that down to shock!

I just hope that if I am ever in such a situation, that I end up with a medical helicopter, police helicopter, SAR helicopter, 3 fire tenders, 4 ambulances, 6 police cars, all on scene within 15 minutes!

If all that gear showed up, I'd be in shock too! ;)

I too am glad no-one was hurt, and pleased to hear your comments Lu. Thanks.

to muffin: if the skids suddenly come unstuck at a very high power setting then there is a problem. Prior to flight you MUST be aware of your expected hover power. With this knowledge any excess collective while still on the ground is an alarm bell that should be going beserk in your head. I've had many skids stick to the ground for a variety of reasons, and so far have had no rollovers for this reason.

Also, the proper R22 preflight where the tail is lowered moves the contact point with the ground aft of the rear contact while skids level. This should break most of the stickiness.

Muffin is correct HT, and so are you. Problem is that they likely did this at the beginning of their flight, and not before attempting to take off from their location.

I'll always do a full pre-flight before first flight of the day. Teletemps, GB oil and fuel levels, sump gas, and a precautionary glance over prior to any remaining liftoffs (if I've been flying it without interruption for the duration, otherwise another full preflight)

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Marc

Found a piece of paper tucked in my R22 Operating Handbook, not sure where it came from, maybe the Robo Safety course?:
"Helicopter operations in snow - Robinson R22:.....If skids stick to the ground on t/o lower lever immediately to stop dynamic roll over." Doh...

No-one seems to have mentioned the other "precaution" (or way of dislodging it, depending on the helo), i.e shuffling it round on the ground with the yaw pedals).

I wouldn't dare offer any advice without first taking out several million bucks' worth of legal insurance, but just thought these ought to be mentioned.

RW-1,

According to jacquestall: "The aircraft was located at a private house some 800m from the airfield boundary at Gamston and had remained on the ground all night prior to attempting its ill fated departure".

Sounds like this was the first flight of the day. So how come they didn't do a full preflight check and realise the skids were frozen to the ground? Sounds an awful lot like carelessness to me, unless I'm missing something here.

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Whirly

To fly is human, to hover, divine.

Whirly,
To hover IS divine, to judge on hearsay is crass.

WB,

>>Sounds like this was the first flight of the day. So how come they didn't do a full preflight check and realise the skids were frozen to the ground? Sounds an awful lot like carelessness to me, unless I'm missing something here.<<

Sounds like it to me too. What else may they have forgone? Cold weather pre-flights can be a b*tch, but you got to do them. Just another case of not taking the proper steps to assure safety, period.

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Marc

4Rvibes,

Then why are we discussing this at all?

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Whirly

To fly is human, to hover, divine.

4Rvibes:
Well said. With you all the way.
A fellow aviator (may have) made a mistake. It's far to early to be sure.
Even if he did, let's just be happy that a few days before Christmas, nobody was killed, nobody was widowed, no child lost a parent.
If the day ever arrived when I knew everything, and never made a mistake, perhaps I'd adopt the Whirlybird approach.
In the meantime, there but for the grace of God ....

Lu: What on earth have your posts, especially the last, got to do with this thread?
Hoverman made a valid point very politely. Instead of taking the point, you just took the opportunity to add yet another anti-Robinson post. Amazing! :rolleyes:

Oh! So it "Sounds an awful lot like carelessness" does it Whirlybird?
That'll save the AAIB a lot of trouble then. :rolleyes:
A little compassion, and humility, wouldn't go amiss.
Well said Hoverman, and others.

To: Nomdeplume.

My last post was in response to taking a swipe at Robinson Helicopters. It has every thing to do with this thread. I made a comment, sombody objected and I replied to that objection.

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The Cat

Yes, nondeplume, carelessness is what it sounds like. But it might not have been; I wasn't there and I was relying on jacquestall's account of what happened. and I could be wrong anyway. And if it was, yes, I too have been careless, many times, and there but for the grace of God etc. And yes, thankfully no-one was killed. All these things are true, why the oversensitivity to an opinion all of a sudden? http://www.pprune.org/ubb/NonCGI/confused.gif http://www.pprune.org/ubb/NonCGI/confused.gif http://www.pprune.org/ubb/NonCGI/confused.gif This is PPRuNe!!!

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Whirly

To fly is human, to hover, divine.

Still pleased that no one was injured as I am sure everyone is. Unfortunate that the skids were not checked (an assumption)for everyone. I have answered so many calls today "...and with all these accidents...."
Just shows what such an incident can do to
public perception. If two other people fell
off a motorcycle on the road nearby and were not badly injured the story would not have travelled further than the end of that road.

Reason for writing though is just to say that
all the good advice in the world on DR deals only with a drifting heli, not one with a skid stuck. By the time the stuck skid breaks free it is practically all over, it's a different game. It happens even faster than the tethered skid which must take up its slack first.

It would be some mighty quick pilot that managed to lower the lever and save the situation. I doubt it is possible. The best advice has to be check first, no matter if the Heli has been there 10 mins or 10 hrs. Easy to check with a Robbie as I mentioned eariler - Use the tail check. The 'power to hover' is also a very good check, well said.

Humour - It can be misunderstood (and don't I know it!). As long as we are all happy with our own conduct then that is often the best we can do. You most certainly cannot please everyone. In that way I am happy with what I had to say on the matter and do not intend to add to it now.

I read that using a bit of pitch and rocking the helicopter for and aft with the cyclic is a way of checking for a stuck skid. Anyone else heard of this (or tried it)?

Nom de plume - Are you seriously implying that just because no-one died in this accident that a complete lack of airmanship should be forgiven. I and many other QHIs spend hours trying to prevent such occurences by highlighting such cock-ups in the hope that our students will never make the same errors. If the reports are correct then the pilot (who sounds like a rich boy with a PPL given his attitude about it being a lot of fuss about nothing) failed to observe a very basic principle of aviation ie completing a thorough pre-flight walkround to ascertain if the aircraft is fit to fly.
I hope he has learned his lesson as is aviation not many people get a second chance!

During training in the Robo we had a simple way of checking if the skids were stuck: watch carefully when the instructor gets in.

Normally the skids splay out and the fuselage sinks. If nothing happens it means the skids are stuck to the ground...

Note: If the skids are stuck, in certain cases the weight of instructor climbing in may even serve to dislodge them.

I think I had that instructor once......... Hmmmm, now where's that C of G?

The green-eyed monster strikes again!

Hoverman - as a person who had to pass what is widely acknowledged to be the best flying training system in the world with the highest chop rate and the highest entry qualifications in order to fly a helicopter I think I am entitled to be pissed off that a civvy with c*ck all aptitude but a fat wallet gets to pollute the air and (ground in this case) and shrugs off a very serious accident as just one of those things!

Sparecrew :

I appreciate your objection to poor airmanship. I don't appreciate jumping to conclusions on nil evidence of someone else's background on flying - even ex-mil pilots have been known to brave Robbies, and also to bend them and other types in a careless manner.

Is it not possible that, faced with the press, the gent concerned was a) feeling lucky to be still in one piece, b) trying to say something non-committal to avoid future embarrassment and c) perhaps still slightly shocked ? And have other people never thought of you as an air-polluter in the sense you use ?

Of course, all the above is based on pure conjecture and no evidence, so feel free to ignore me and make your own minds up.

At least, having seen this, I know I've got one more thing to do on my walk-around.

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I got bored with "WhoNeedsRunways"

Yes, there but for the grace me too!

This chap was unlucky that his mistake (if he made one) was very unforgiving.

I had a little grin at the thought of watching the skids spread when an Instructor got in! It is a good and valid point, much truth in it but the thought of an Instructor in my past(The fat controller) just creased me!

Haven't written just for that. There have been some wise words on pedal/tail waggling. They are good moves for surfaces that have 'suction' or stickiness but I have to doubt they would have worked in this case.

An R22 TR produces circa 72 Lbs of thrust.
The MR (we do not know how much power was being pulled but it must have been enough for a vertical lift otherwise the roll would not have occurred) is doing its job whilst the skid or skids are/is being held down.

That would be around 1300 -1370 Lbs of vertical(if the stick were properly centred) thrust. It seems reasonable to assume that if the MR couldn't break the skid(s) free at (say) 1000 Lbs thrust the TR isn't going to do it with 72 from the end of a long and flexible tail. (I have thought over the lever/arm principle but doubt it has much bearing here.) I think that if the Heli were held firmly enough to the ground by frost or ice, all that would result from pedal juggling is tail deflection.

I realise it is different in many ways, the skids lie in a different plane for the TR and MR thrust but I think the figures are overwhelming.

I lived in England long enough to have many things very firmly welded to the ground by ice, thankfullly none of them were my helicopter!

The sad thing is that you could say the Heli was not bonded to the ground firmly enough.
The pilot's warning lights and bells (in his head) might have come on if he got to 23-24"
and was going nowhere, having both skids equally well stuck. What caused this roll was only one of them 'letting go'.

If a lot of power is applied whilst only one of the skids was either not stuck at all
or it broke free first, that certainly sets up momentum in a direction none of us want.

Anyway, this is not said to dilute any of what has been said on the matter. What it actually is intended to do is to underline
the real point. It just cannot be got away from. I very much doubt that any pilot could
be as fast with the lever as he would have to be to recover from this 'catapult' type of roll. It is all over when the Heli gets to 42 degrees (or less with full fuel) anyway, no amount of lever lowering will stop the roll then.I also doubt that a Heli stuck that fast to the ground would be freed by pedal juggling in any but the mildest of cases.

It would be interesting to know which side
the Heli rolled to. I've been making a little study into DR for while now. My view is that it is most often a roll to the left (with anti clock MR) for many reasons, principally because of the left skid low attitude and a couple produced between TR thrust to the right and horizontal MR thrust to the left.

Then again, that is only valid with a roll caused by drift.

This one wasn't caused by drift at all and either skid could have 'let go'first. Whichever side it was would govern the direction of the roll.

Getting back to the point I was about to make, I do know one thing with absolute certainty.

If the pre - flight check includes leaning the tail down, levering the skids or testing
using the ground handling wheels to lift the skids no recovery is required as the prevention will succeed.

Imlanphere :

I have read about this technique, but only in relation to a Huey in Vietnam on a boggy field - sticky but pliable enough to be prised free.

Whether it would work on ice is a different matter, and on the R22 it's small enough to pull the tail gearbox downwards, different altogether in something a tad larger.

As SPS says, prevention is the only sure cure.

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I got bored with "WhoNeedsRunways"

Hey SPS,

I agree with you on not noticing something not right (not light on skids, etc.) at 23'-24'.

No where else is an activity so unforgiving of complacency and innattention to detail, but it is still rewarding isn't it? (Like when you drop into a confined area, etc. :)

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Marc

The days of vines and noses:

NTSB Identification: MIA01LA007
Accident occurred OCT-17-00 at MARIANNA, FL
Aircraft: Robinson R-22 BETA, registration: N621DM
Injuries: 2 Minor.

This is preliminary information, subject to change, and may contain errors. Any errors in this report will be corrected when the final report has been completed.

On October 17, 2000, about 0800 eastern daylight time, a Robinson R-22 Beta, N621DM, registered to and operated by Skycopters Incorporated, as a Title 14 CFR Part 91 aerial observation flight, experienced dynamic rollover during takeoff from a field in Marianna, Florida. Visual meteorological conditions prevailed, and no flight plan was filed. The pilot and passenger received minor injuries, and the aircraft incurred substantial damage. The flight was originating at the time of the accident. The pilot stated that his headset came off in flight, and he had landed in a field to secure the headset. The pilot further stated that while attempting to take off from the field, the helicopter's right skid became entangled in a vine, and the helicopter rolled over and incurred substantial damage.

RW 1 do you know this guy? This is what can happen when you fly with the doors off.

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The Cat

[This message has been edited by Lu Zuckerman (edited 23 December 2000).]

To: RW1
I tried to do exactly what you said about paying for one hour in an R22 to demonstrate the tendency for the disc to tilt left when the cyclic was pushed forward. Guess what, the only R22 in this area was destroyed in a dynamic rollover.

Fate is the hunter.



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The Cat