OK, what caused this accident? (Video) [Archive]

PPRUNE FAN#1

8th Dec 2003, 00:18

We've been over this before. Looks like neither of the geniusi in the 206 put much thought into what they were doing, and were obviously in one heck of a rush for some reason.

We see the guy in the left seat hand one end of the rope to someone in the boat. We do not know where the other end of the rope is attached to, but we can guess that it's not the cargo hook, as the aircraft does not appear to be so equipped. That leaves either the left skid/crosstube, or perhaps the left-side door post (and then out over the left skid). Whatever. As the pilot pulls power to start the tow, the inevitable happens.

Looks to me like the guy in the right-front seat was horribly a inexperienced helicopter pilot with an incredible lack of talent (I wonder if he posts on PPRuNe?).

Odd though that the narrator of the clip should refer to a 206B as a "million-dollar helicopter." If that's what people think about a lowly JetRanger, imagine what they think an S-76 costs!

headsethair

8th Dec 2003, 01:30

"million-dollar helicopter" : he's squawking about Oz dollars. A 206 with the Oz import duty is about a mill.

This video should be compulsory for every pilot - just as they pass their flight test they should be made to watch this. And then again at 50,100,150 hrs etc.

In fact, it should be fed to the gps screen of every helicopter at start-up!

odonnella

8th Dec 2003, 01:40

That is one of the daftest rescue attempts I have ever seen. As pullning the power on requires left pedal anyway and the machnie is being dragged to the left by the tow also, is it not more likely he ran out of tail rotor pitch rather than cyclic and was unable to prevent it spinning? The machine appears to yaw to the left before being pulled in by the tension in the rope and the pilot appears to be unable to prevent it.

Reminds me of the famous helicopter rescue attempt in the film Jaws 2.

John Farley

8th Dec 2003, 02:48

Barannfin.

Perhaps he ran out of cyclic

Too right! The drag load of the heavy virtually stationary boat was acting through the front port skid attachment. This would have applied a huge nose down pitching moment. To be safe he needed to take up the slack nice and gradually then when he felt the ONSET of the (inevitable) nose down trim change he should have countered that with aft cyclic, maintained his attitude and waited for the boat to gradually start to move without pulling any more collective and generating even more nose down trim change. Once he had got the ensemble drifting forward nicely he could have gradually increased power within his ability to hold the nose down trim with say one third back cyclic.

But he knows all that now!

Flying Lawyer

8th Dec 2003, 05:33

John Farley

Pleased to see you posting in this forum John.
Quite a few contributors are rotary and fixed-wing qualified, but we don't get many f/w-only pilots. That said, you do have a lot of hovering time. ;)

Tudor Owen

sycamore

8th Dec 2003, 07:08

It looks as though the 206 is fitted wiv an `ook, or certainly something where the `ook would be.So, he`s actually run out of everything, cyclic, yaw, and power, and as John says, if only they`d have thought about it, even looped the rope around the cabin floor, and out between the skids, and then eased off gently, they all might have been home and "dry...

John, were you around when there were trials at RAE/AAEE towing a minesweeper( well, not actually there, but you know what I mean)?

Syc..:ok:

PS. and no,I don`t think a Lynx would`ve` been able to tow the frigate off the rocks!!

Rotor1

8th Dec 2003, 11:38

the pilot was visually impared by the swim suit clad ladies in the boat:ok:

helmet fire

8th Dec 2003, 17:48

******!

Bronx: I reckon the answer to your question has two possible answers but the video is not clear enough to be able to determine which.

Perhaps the rope is connected correctly to the cargo hook (hook looks fitted in the video I watched ), but then instead of taking the tension slowly, the pilot seems to nose over and begin to pull. As he is not over the top of the load when he begins to pull, it is just as if he had snagged his line in forward flight, ie the aircraft begins to pitch downwards, and the rope pulls him down. There is a momentary cause for misguided joy by the pilot as the boat overcomes its inertia and begins to move, but even though he is now accelerating well, he is still being pulled down. As this realisation comes to him, he probably pulls all the power he has in the hope of missing the water and this has three immediate effects: he gets pulled down faster, he runs out of left pedal (begins turning to the right), and the passenger notices a strange poo smell coming from the pilot. :}

The other would be that the rope was around the left skid, as several have said above. If this was the case, I am very suprised that the aircraft did not bank far more harshly to the left and continue to accelerate in its left rolling moment all the way to the water, a la dynamic rollover. I say "suprised" because I had always imagined it would be far more violent that the video.

Wonder if he tried a release?

John Farley

8th Dec 2003, 18:46

Flying Lawyer

Thanks, I did have the privilege of flying choppers a little for the boffins at Bedford. One day I lost a small pointed and dense underslung instrumented load from a Whirlwind 7 when the parachute intended to float it down candled. It embedded itself deep in a ploughed field, but the parachute was visible above the surface. To save my team a lot of shovel and spade work I was talked into landing alongside, fixing the cable to the chopper and trying to pull it all out. It was my first experience of tethered hovering and like a lot of first experiences it did not go too well. I got into a very nasty lateral oscillation as I pulled. When in a chopper close to the surface there is an instinctive desire to pull more power as a general solution to problems. In my case (as with the boat tow case) this was actually only going to make matters worse as you have to reduce power to get rid of the line tension which is the root cause of the problem. And that is not instinctive. I did not do it then either, but was fortunate to have the services of a cable cutter.

The only way to really learn so many things in aviation is to make a mistake. The trick is to survive the mistake....

IHL

8th Dec 2003, 20:55

Its an inovative form of dynamic roll-over.

Heliport

8th Dec 2003, 21:09

Just in case any of our younger or non-UK members didn't understand why Flying Lawyer was teasing John Farley about hovering ……….

John is a distinguished test pilot. He first flew the P.1127 (fore-runner of the Harrier) in 1964 while at the Royal Aircraft Establishment and spent 19 years of his career contributing to the development of the Harrier.
After retiring as Chief Test Pilot BAe Dunsfold, he spent five years as Manager of Dunsfold and a further two as Special Operations Manager at BAe Kingston.

If anyone would like to read about hovering a fixed-wing, this is a link to the text of a lecture John delivered to the Royal Aeronautical Society in May 2000:

The Harrier Development Story - by John Farley OBE AFC CEng (http://www.harrier.org.uk/history/history_farley.htm)

MaxNg

9th Dec 2003, 03:37

If you think that this guy qualifies for Numpty of the year what about the two Jetrangers joined together by tow rope from Hook point to hook point so a stunt man could walk from one A/C to another, apparently the producers of the show had approached several operators and told in no uncertain mannor where to stick thier Idea, exept these two numpties decided to do it.

Guess what happened whet they lifted off.

I will try and find the photo but if any one else has a link it would be appreciated

:rolleyes:

bugdevheli

9th Dec 2003, 04:53

I have just conducted an experiment to determine why the heli rolled over. I used one dog, one collar, one lead. I attatched collar to dogs neck to represent the place in which the rope was tied to the helicopter. I ran lead from collar around left side of dog and under his belly, leaving remainder of lead draped along floor behind dog. Threw large bone in front of dog. As he accelerated away (as per helicopter), stood on lead. Result. Dog goes arse over tit just the same as the helicopter. Simple:D :D

Flight Safety

9th Dec 2003, 08:05

To add my 2 cents....

All you have to do is look carefully at what happens to the boat.

It appears that the pilot got the slack out of the line OK, but the initial pull on the boat was enormous. The helo pulls the boat up instantly to plane on the water and accelerates it rather quickly. Just look at the wake it made.

I think the acceleration after planing of the boat (from very large forward thrust) is caused by applying full collective after the pilot runs out of aft cyclic during the pitchover, when he realizes he might go down. With full collective applied, he probably runs the rotor RPM down quickly, and lowering RPM combined with hard collective causes an LTE that yaws the tail boom to the left just before it hits the water. The reason I think the pilot must have had full collectve applied up until he hit the water, is because the boat doesn't slow down until after the water impact.

Like others, I can't see clearly where the rope is attached to the helo, but this is basically the pitch forward version of a dynamic rollover. Like John said, it wouldn't have been so bad if the pilot had gradually started moving the boat. It was the stump pulling power start that got him into trouble.

Too bad the rope didn't break under the load.

Flying Lawyer

9th Dec 2003, 08:25

bugdevheli

Now that's an explanation even I can understand.
I don't mind if it's right or wrong - brilliant. :)

9th Dec 2003, 09:49

IHL was perfectly correct...

A very innovative form of dynamic rollover..

Game over, insert another couple of hundred thou.. (and another ass)

Steve76

9th Dec 2003, 22:56

I thought I could quite clearly see the line over the LH skid. Definately dynamic rollover.
I was interested in the decending LH turn to approach the boat....seemed a little bit hurried if you guys know what I mean.

Guys in the Canadian Navy attach themselves to boats all the time. They seem to have little trouble with it in serious sea states.:E

Cron

10th Dec 2003, 00:17

Agreed FL, very descriptive. Now I got it. (What type of Dog was it B?)

bugdevheli

10th Dec 2003, 05:25

Thank you FL and CRON Patterdale terrier. No ,never heard of em either. Best features,. Love experiments and have a similar build to a Jet Ranger.

Capt Hollywood

10th Dec 2003, 22:02

Using the combined resources of my VHS video recorder, my mini DV camcorder, my laptop, Pinnacle home studio, Photoshop and my website I can finally post these pics!

They would seem to clearly show that the rope is indeed attached to the cargo hook and does not appear to be hooked over either skid.

You can also see that the boat hasn't actually broken down as they start it up in rather a hurry to assist the crew!

Cheers,

Hollywood :cool:

http://www.danodwyer.bigpondhosting.com/photos/9bba0356f5063472fd809652c5074c76.jpg
http://www.danodwyer.bigpondhosting.com/photos/dff0a8167d8621d127cba442effbd588.jpg
http://www.danodwyer.bigpondhosting.com/photos/7bec3e32312853820d03ac0bb63c525e.jpg
http://www.danodwyer.bigpondhosting.com/photos/1679258a884f7953dc2a8cd4c8d1cc07.jpg

John Eacott

11th Dec 2003, 05:44

Danno,

You've obviously got way too much time on your hands up there in the frozen North ;)

Has anyone any idea where this all happened? I can't make out the rego, and couldn't pick up any obvious location.

Speechless Two,

Intriguing tie down on the Wessex, any recollection why you would have done a high hover instead of using a tie down base on the ground? I like the 815 reunion site, looks like you had a good time :ok:

bugdevheli

11th Dec 2003, 06:20

Come on Bronksy put us all out of our misery!!!

Flight Safety

12th Dec 2003, 01:58

CH, excellent photo work. However I'd like to disagree on one point. You said You can also see that the boat hasn't actually broken down as they start it up in rather a hurry to assist the crew!
I think if you watch the entire video, you'll see that the pull of the helo put the boat in motion, and that it was coming to a stop after the helo hit the water.

It's nice to think they started thinking of the crew that quickly, but at the end of the video, the folks in the boat still look scared.

BlenderPilot

12th Dec 2003, 03:04

Hollywood,

You have all my respects as an image guru! Amazing work !

Did you get the images from the same video we have all watched? (Windows Media 328KB file)

Can you make the registration? Let me guess, its an XA-_ _ _ right?

Damn, I've got a story to tell. (although I really don't want to.)

John Eacott

12th Dec 2003, 05:00

Waiting, waiting.......

That's worse than not saying anything at all ;)

Flight Safety

12th Dec 2003, 05:01

OK Blender, spill the beans....

T_richard

12th Dec 2003, 05:13

Ah there is a question from the civilian in the back. What is the minimum cruising speed of the helo in question? That boats hull speed probably tops out around 50-55kts.. After that the drag from the hull goes through the proverbial roof. I am not challenging the analysis of the pros, just trying to add my pence worth. By the way I like the dog on the leash explanation. Very clear and very funny

Capt Hollywood

12th Dec 2003, 06:46

Thanks for the kind words. :ok:

Flight Safety,

I agree it was coming to a stop as the 206 hit the water but the video I have is much clearer than the link posted on this thread. I recorded it directly off one of those 'Funniest Home Video' shows and then downloaded it into my laptop at mini DV quality, my clip is about 14mb in size! In the footage I have, the driver of the boat is sitting on the front of the boat as it is being towed, then the rope snaps and he jumps back over the windscreen of the boat and fires up the engine. The last two frames I posted are from the very end of the clip and you can see the spray coming off the prop as he fires the engine up. I think it was more of a stunt than coming to the aid of a boat in distress. :hmm:

Blender pilot,

As mentioned above I recorded the footage off the telly myself so it's much clearer. Unfortunately not quite clear enough to make out the rego. I have slowed it down a little though and you can see that the tail section actually breaks clean off about a 10cm in front of the vertical stab. Any prizes for inventing a statement for the insurance claim form............there's a whole new thread right there!

Cheers,

Hollywood :cool:

Flight Safety

12th Dec 2003, 23:17

Capt Hollywood, from the video you saw, you don't think it was a stranded boat rescue after all?

Hmm....

I may not be the sharpest tack in the box, but using a helo to tow a boat that actually has a good engine and fuel in the tank, sounds totally askew. That might somehow account for the fast start on the tow. Maybe blender pilot can shed some light on this.

This is starting to get interesting....

Agaricus bisporus

13th Dec 2003, 00:24

Seems to me that "lack of imagination" kinda sums it up, but that's being kind.

Didn't the numptie think about the likely result of the obviously lightweight rope snapping, or coming loose/being jettisoned from the boat? It would have snapped back at the helo and almost certainly got wrapped in the tail or main rotor. To make such a connection without a long and thorough briefing with the "ground" party is nothing short of stupidity and incompetence.

That extraordinary zero level downwind turn before passing the rope. I get the feeling he had the collective under his armpit and full boot on as he visibly sank towards the oggin in that manoeuvre, it was only the poor old Jetranger that got him out of that pickle, bless it. First time I saw the clip I thought that was where he was stoofing in.

Then the insane angle of pitch as he accelerated away. That big heavy speedboat was hoicked onto the plane in a second or two. Where was the caution, care and finesse in that? Nowhere, mon frere!

And, as someone noted above, he made no effort to ensure he was perpendicular to the load, he was clearly way off to the left of it. Result? a big couple between the lateral pull on the hook and the thrustline of the rotorhead equals roll to the left. So he pulls harder (if not at max torque anyway, which I suspect he is) , rolls harder, runs out of rt cyclic to oppose roll left as couple overpowers cyclic and SPLOSH!

Scary to think that someone with a commercial licence would do such a thing.

If the registration prefix is visible then surely the national accident reports will give the whole story???

Capt Hollywood

13th Dec 2003, 01:33

I may not be the sharpest tack in the box, but using a helo to tow a boat that actually has a good engine and fuel in the tank, sounds totally askew.

Flight Safety,

"Totally askew" might be a bit of an understatement. I don't think I'm too far off the mark in saying that it was a stunt or just plain showing off. At the end of the clip it shows several other boats coming to the aid of the downed 206 within a very short time, I'm sure they could have aided the original boat if it had a problem. Also, let's assume the boat had a legitimate problem, how did it alert an aircraft that it would require a tow and did there just happen to be a 206 in the area with a line already attached to the cargo hook? In the clip I have you can see that the line is attached to the cargo hook and runs up to the passenger in the co-pilot seat to allow him to hand it to someone!

Of course there is always the possibility that the boat did just breakdown, the sailor managed to flag down a passing Jetranger, radioed that he would be requiring a tow to the nearest boat repair facility, and so on!!!! ;)

Me thinks this was planned, but not very well! :hmm:

As for the rego, you'll have to make up your own mind on that one.

http://www.danodwyer.bigpondhosting.com/photos/94f28c4e9b7f7ab39f9a97a224310edb.jpg

Cheers,

Hollywood :cool:

BlenderPilot

13th Dec 2003, 02:54

XA-_ _ _ registration, damn! I knew it!

I knew the pilot, and have even seen the sawed off cyclic one of the local guys collected as a souvenir from the wreck!

Give me a day to me prepare mentally to admit this happened to someone I know and tell the story. (gather all the precise info)

Clue: Happened here, and the boat was working perfectly.
http://www.flymex.com/mexico/Photo_Album/viewclouds.jpg

T_richard

13th Dec 2003, 02:59

Let me guess, the pilot saw a spandex bikini that looked very appealing and decided to use his "big strong helo" to get a bit of something later on. Am I right?

RDRickster

13th Dec 2003, 04:40

BlenderPilot, you ba$tard... you can't keep us in suspense like that! :D We need details (leave registration numbers and actual names out of it, if you prefer).

SASless

13th Dec 2003, 08:12

Watching the video gave rise to some old naggng questions....one of which is "why ever would the US Army put two teenaged W-1 Warrant Officers together in a UH-1 Huey and think things just like this would not happen?"

I can assure all readers that a "lack of imagination" could never be the issue.....lack of commonsense, maybe....dual simultaneous brain infarctions, maybe....twin cases of the roaring dumbass.....but lack of imagination? Never!

:ok:

RDRickster

16th Dec 2003, 06:43

Are you going to enlighten us? :suspect:
I kinda feel like a mushroom... kept in the dark and fed fertilizer! :p
Show me the light, My Brother! :cool:

Ian Corrigible

12th Jan 2004, 02:56

The link to the video of the failed "JetRanger tows speedboat" experiment seems to have expired. Does anyone have another link to the vid ?

Thanks,
I/C

Head Turner

15th Jan 2004, 22:18

A big cock-up. However, as I see it;-

The tow rope was routed around the front left skid post. This caused a pivot point at which the nose rotated down. Cyclic used to counteract this effect but the rotor head is offset ie above the pivot point.
Maximum collective applied to avert a nose into the water.
Full right pedal used to counter torque.
Cyclic effectiveness was nigh on zero as couple between pivot point and rotor head would still be in front of the helicopter even with full aft cyclic.. Total Rotor Thrust roughly perpendicular to the mast.

A question is raised here.

When/if full collective is used, then how much cyclic authority remains? This assumes that there is a limit to the pitch that can be applied to each blade, and if some is used for collective then what's left must be all that can be used for cyclic control.