Bristow Academy 206 down, Florida

[helihub]

Strong set of skids here. All 3 POB out and OK, refusing hospital treatment

Press story at 3 Survive Helicopter Crash in Titusville | firstcoastnews.com (http://www.firstcoastnews.com/topstories/article/245565/483/3-Survive-Helicopter-Crash-in-Titusville)

Slightly wider angle photo in the video at Helicopter crashes near Titusville during training (http://www.wptv.com/dpp/news/state/helicopter-crashes-near-titusville-during-training)

http://www.firstcoastnews.com/images/640/360/2/assetpool/images/120306121825_03062012_chopper.jpg

[baby spanner]

the blades are still in the head.... and the aircraft look in good shape conciderng...

[wardy20]

Glad to hear all are ok

[DauphinDude]

That is the fifth (?) accident in 2 years :/

[GoodGrief]

That is the fifth (?) accident in 2 years :/

Might be, but it has to be put in perspective. Figure in the amount of students, FIs, hence training and flight hours.
My guess is the school sells far in excess of 20000 flight hours per year.

[muermel]

Really? Which would that be?

[mickjoebill]

My guess is the school sells far in excess of 20000 flight hours per year.

5 prangs per 40000 hours... what is the industry average?

We could do a survey here.. pilot hours per prang?





Mickjoebill

[FairWeatherFlyer]

Good to hear all are ok.

I'm not sure if a single statistic is going to differentiate on training, charter, lifting, filming, various authorities, differing geographical/weather conditions, damage, injuries, fatalities?

[MartinCh]

low G/mast bumping very low?? Did that happen before?

How else would more accident versed guys explain the separation of MR like this and a/c upside down with skids seemingly intact? Too abrupt/large forward cyclic on departure/climb, yet still low level and not too fast?

Wouldn't hard landing damage skids? Then rolling on side, blades destructing themselves, etc?
Was the tailboom broken by itself or hit by MR blade? Blades look 'too good' for tailboom strike or regular rollover.

Glad there are bruised egos and machine, not lost lives/serious injuries, indeed.
If it was what I think, very, very lucky, vs at least one of the R66 down probable cause. Get that couple hundred feet up and it gets ugly fast.

[Gordy]

No doubt I will be accused of stirring the proverbial sh*t, as I always am when I even breathe near a BA post, but I will give my constructive $0.02.

MartinCh

Wouldn't hard landing damage skids? Then rolling on side, blades destructing themselves, etc?
Was the tailboom broken by itself or hit by MR blade? Blades look 'too good' for tailboom strike or regular rollover.

Not necessarily. They had an accident in 05 very similar to this. Read the report HERE (http://dms.ntsb.gov/aviation/AccidentReports/aomozl45murjdw45ky0cbh3m1/Y03082012120000.pdf). The report is extremely vague, (I wrote it that way... ;) and no I was not on-board, I just did the paperwork). In this case the instructor was not signed off for doing full down autos and was doing "power recoveries". The aircraft hit the ground hard and bounced about 6 inches forward---during the bounce, the instructor pulled aft cyclic and severed the tail boom. The aircraft remained upright with the main rotor system intact. The tail boom was cut at a similar point as is shown in this latest accident. There was no bending or distortion on the landing gear skid tubes. Unfortunately I do not have my pictures of this accident with me---they do show all the ground marks pretty well.

Without knowing anything further, I would like to suggest that this might have been a repeat of the 2005 accident in that during the flare/touchdown portion of an auto, (whether it be simulated or real), the aircraft bounced, aft cyclic was applied thereby severing or distorting the tail boom, T/R authority was lost, the aircraft started to spin with bank angle, a skid contacted the ground and due to the momentum, the aircraft rolled onto its side.

While we are on the subject of autos, one thing that Shawn Coyle and I discussed during his visit to the academy back then, (it was still HAI at the time), was conducting full downs to grass vs hard surface. That may or may not have changed the outcome on the 2005 accident---I tend to think it might have had a different outcome. On grass, the skids dig in which negates the "flex" capability of the system. On a hard surface, a fair amount of the downward energy would be absorbed by the flexing undercarriage and the aircraft "may" not bounce.

For the Bristow "sensor" who likes to accuse me of "stirring"..... All of my comments here are my opinion, are stated for the purpose of continuing education and speculation, and are in no way intended to discredit anyone. It is after all called :

http://images.ibsrv.net/ibsrv/res/src:www.pprune.org/get/images/misc/pplogonew3.gif

[malabo]

Nice write, Gordy. I agree with your perspective.

Been in that "oh s**t" situation where the student has left the flare a little late and you (the instructor) didn't catch it in time. Fast slide-on with a collective pull will take care of it, let the skid gear do its job. Bell Academy did all their full-on auto to pavement, and there is more noise (and sparks at night) than grass. Sounds like hell, but the skid shoes do their job, and are replaceable. Almost doing a nose-stand on grass once that turned out to be mud teaches a few other cautions about checking the grass surface carefully - it is also less tolerant of side-drift than pavement. Almost funny the way some simulators are programmed to give you different feedback if you auto onto grass or the runway.

Recent AStar fatality on the West Coast here from an engine failure on takeoff had the comment that if had come down on level ground instead of deep snow, the gear would have done its job and absobed the vertical shock. Instead the cabin took the full jolt.

[MartinCh]

Thanks Gordy.

The bounce is plausible, I just don't get the blades with hub separated and ending up like that. Still together. You've been flying those machines for ages, so you know more about it. What you said is more likely than low G pushover. By the time people do Jetranger transition, they should be careful enough.
The mishaps mentioned earlier that happened in the past, well, there could have been more had BA used R22 as main trainer and not more forgiving S300.

I looked at the report. 6k+ heli time and 1300 206 time? I guess people can get caught out at any level. There were few articles about full downs to grass vs tarmac/concrete. I'd not dare to do full down in R22 to grass, especially little to no wind. I've heard/read of people flipping over machines in muddy etc terrain doing full downs practice, even off airport.

So, to take some advice form Gordy's words, if people end up doing flare too low and too late to arrest the descent rate, then they should rather slide forward bit more than yank back and possibly cut the tail a bit. Even more so in two bladed helicopters. If bouncing anyway, better level with forward motion than on heels or aft cyclic making things worse. Still lots of variables in any auto, though.

[Shawn Coyle]

Anyone who wants a copy of 'Pass on the Grass' (why you shouldn't do touchdown autorotations to grass), please PM me.

[206Fan]

Shawn,

Is that a book of yours? If so I would be interested to have a look.

In my case in Ireland all I have is Grass if an Autorotation had to be done.

[nigelh]

Don't do full down autos at all and save all of us ( owners ... Not pilots ..) a load of cash on our premiums !!!!!!...... Apart from ,admittedly , being fun they are totally unnecessary and have caused the writing off of 10x as many aircraft than have ever been trashed by genuine engine failures . Instructors seem to be mesmerised by practicing something that ( from 2ft up .... ie you practice power recovery after the flare ) is v v unlikely to kill or even hurt you . If you can get the machine to 2-3ft and near zero ground speed then forget the rest !!!
I certainly now would never allow autos to the ground in any of my machines and will expect my insurance co to take that into account .
Ps. If you can cock it up in a 206 god knows how you would have ended up in something more tricky ......

[Gordy]

nigelh

Don't do full down autos at all

While I may agree with you in principle, some organisations require it, and to be honest, in some aircraft it is easier to put it on the ground than to try and power recover.......

[krypton_john]

Anything with overhead throttles!

[XV666]

they are totally unnecessary and have caused the writing off of 10x as many aircraft than have ever been trashed by genuine engine failures.

And you know this because you have heard it somewhere?

Against which you have (of course) added up all the aircraft that have been saved because the pilot was proficient in engine offs, and was therefore able to hand in a perfectly useable airframe at the end of the emergency?

:rolleyes:

[Arm out the window]

the student has left the flare a little late so you are low and fast, and you (the instructor) didn't catch it in time. Fast slide-on with a collective pull will take care of it, let the skid gear do its job.

If you're not in a position to accept a fast ground slide, this will also work as a last-ditch bum-saver:

Student leaves the flare too late (which is kind of your fault anyhow, but having got yourself in the position you have to deal with it);

Take over, reef up on the collective to quickly get some height under your tail, then immedately flare hard and lower the collective again to regain / maintain rotor rpm (flare 'zoom' and collective reduction should balance eachother out if judged right, keeping you at the right height);

Now you should be back in a relatively normal 'end of auto flare' position, continue as usual.

It's not for the faint-hearted, but it does work.

[Savoia]

Some good points raised so far.

Certainly (for the reasons mentioned) using a firm surface such as asphalt or concrete is advisable but grass tends to be kinder on the airframe - less vertical 'shock' (through the absorption of some of the energy by the ground on initial touchdown) and sometimes, depending on the surface, less 'juddering' to the skids during run-on.

Checking the touchdown zone is truly an important consideration and can save much heartache later on!

Its been posted before but its such a good example of a 'classic' 206 auto that its worth repeating:

A8CgMEnoyVo&feature=related

Back in the day some insurers would get pretty specific about what could and what could not be done when it came to autos. More than one 206 I flew had approval for touchdowns .. with the provision that this be carried-out only when the craft was wearing shorts (ie. fitted with low skids). Certainly the lower centre of gravity with short skids helps.

Would be interested to read a summary of Shawn's 'Pass on the Grass' booklet if someone would care to post the highlights.

Regarding touchdown autos in general; I always found they inspired confidence, especially when taught by a capable instructor. I do believe that getting that 'last bit' right is important!

Bell Academy did all their full-on auto to pavement, and there is more noise (and sparks at night) ..
Have some interesting memories from the US which involved spraying a stream of sparks from a set of 206 skids during night t/r failure training and which involved putting the bird on the taxiway at around 30kts or so but that, as they say, is another story!

[vaqueroaero]

I've done hundreds of touchdown autos at night, both with NVG's and without. The only time I've seen sparks was when we lost a skid shoe and the the skid tube snapped. That was impressive.

With regards to full downs being unnecessary I couldn't disagree more. The main problem that I have seen doing power recoveries is that people terminate too early. People trained to do that, unfortunately in the real event, will do what they have been trained to do. There is no use being trained to terminate an auto at 20 feet agl.

We had a technique on power recoveries where we would bring the throttle in prior to the flare. Once the flare is complete and collective is being brought in to cushion, the throttle is rolled off to terminate with a hovering auto. This works great, but be warned if you or the instructor are not very proficient at it don't try it as you can end up in a spectacular over torque.

The most important thing in a Jet Ranger at the end of an auto is GET IT LEVEL!!! You can drop a Jet Ranger from a frightening height and as long as she hits the ground level you can get away with no damage. Seen it and done it. Either that or my guardian angel was working overtime!

One last point. From an instructors point of view every autorotation should be treated as though the engine will fail and a power recovery is not an option. Then if it does fail you are not caught by surprise and are already mentally prepared to take it to the ground. Be careful where you roll that throttle off.

[MartinCh]

Yeah, those 206 autos are way easier than R22. Even the R44 rotor inertia is way better than little Robbie. What a luxury, having that much time and inertia being couple inches off the ground for so long to get it right.. The only issue for power recovery could be the spool up time in turbines, but I'm too rookie to know turbines personally.

Savoia, the article Shawn wrote should be in one of the Vertical magazine issues.

Agree with vaqueroaero. As my high time CFI course instructor/'old timer' reminded, regarding doing off-airports autos, that the power recovery may not happen and therefore suitable place to set it as if for real, is important.
Night full downs? Hm. I wish I was that good to be comfortable with them in future. But I'm not military, so I guess I'd not get to do that.

[nigelh]

Just a couple of points ...
1) I am not against EOL ,s in principle but think that follow through demos from the instructors is enough .
2) When i did my training in the States we never did them to the ground because a) the owners didnt want it and b) the students didnt want to take any risk of damaging a ship and delaying their training !!
3) Power recovery at a height of between 4 and 8ft should ensure that you get out in one piece . I know of many many machines written off or badly damaged practicing but only know of one or two saved in a real failure . I can also say that when i had a total failure i landed it fine AND had only done power recoveries . This shows that if you do the recovery at the end of a flare which brings you to the correct height and speed you actually have very little else to do !!
Just pull collective and keep cyclic centred and thats it .
Lastly i would accept that my views as an owner will be different to a lot of you guys who just fly and dont pay the bills ...or the premiums ..

[anti-talk]

Nigel,

Unfortunately I dissagree - EOL's are required by the Licence Issuing Authority here for all instructor training.

Additionally I strongly belive that any CPLH student should have the confidence in the machine and the ability to be able to put the machine on the ground in the event of an emergency (especially if they are going to be using the shiny new CPL H they have earned).

We routinely teach EOL's to the ground in the R22/R44/S300 machines but ALLWAYS to a hard paved surface and unfortunately its a training risk we have to accept as an operator in order to deliver our product.

Hope you are well and its sunny in 'ULL - should be over in the next month or so for a quick visit.

Geoff

[nigelh]

Well if those are the requirements then I accept they need to be done .... I just wish people wouldn't mess so many up with the resulting higher premiums !!!!
Hope all well in sunny Florida ....thinking of coming over to do IR .....seems a waste flying around in 109 vfr !!!! N

[Upland Goose]

In the Bristow of old we never carried out touchdown autorotations on high skid gear equipped B206's (AB206's). We never carried them out to a paved surface although I do remember doing them out in the desert in Dubai on hard sand.

We would swap skids to train - not negotiable. Maybe they had learned from hard experience.

With the low skid gear the rotor mast is vertical when the skids are parallel with the ground, so if you are at almost zero ground speed at the correct height - all should be well.

If you have a slightly higher forward speed at touchdown then the lower CofG helps to save the day. Maybe the Academy should look to the past - easy to say that now, of course! UG:p

[Shawn Coyle]

High skid gear - hadn't thought of that for the upcoming book (Little Book of Autorotations), but will definitely include it.
Once again, pprune's rotorheads come through with great feedback and ideas.
Keep it up!

[Arm out the window]

In the Aussie military system while I was involved (not recently, only up to about '95) our touchdown autos - and there were lots of them - were done almost exclusively to grass.

You would always check it out first so you didn't use anything too spongy, and it was very kind on the skids and pretty straightforward. Firm, dry, shortish grass is good.

I heard of a few problems where guys ended up rocking forward on the toes when the skids dug in on softer grass, but in general it worked very well.

This was Hueys and Squirrels, and I know the Kiowa guys did it too.

[autoranger]

Interesting discussion about an accident that may not even have been a result of an autorotation - anybody have the facts? ...and I hear that BA are flying more like 35,000 hours a year ...and five accidents in the last 2 year's seems excessive - maybe more like 2 or 3 with no injuries so the accident rate as set against the industry standard of accidents per 100,000 flight hours is pretty low compared to the US or worldwide training accident rate.

[Gordy]

autoranger...

Welcome back.....I wonder who you work for.... :rolleyes:

I do agree with you though:

Interesting discussion

All in the interest of learning and education....which is what Bristow is all about right.....? Even I was forced to think and learn about something on the interesting thread----how high skid gear and vertical CG can affect your stability in the touch down phase of an auto.

Tis all good.

[skastdk]

http://img706.imageshack.us/img706/4531/imageuploadedbytapatalko.jpg

[Upland Goose]

Looks like the autorotation to the ground "conspiracy theory" was duff. Nevertheless, it was all good stuff.

Could we have the dynamic rollover protagonists come forward please. Not my forte. UG:O

[EN48]

hadn't thought of that for the upcoming book (Little Book of Autorotations),



Your fans are more than eagerly awaiting this! Going to happen in our lifetime?

It is my understanding (possibly wrong) that the practice lanes at BTA are paved with a "fine grained" asphalt that further reduces friction and the possibility of hooking a skid. IMHO, it is quite important to know what the nature of the surface is to which you are doing practice (touchdown) autos. Not all asphalt is created equal. Grooved runways at larger airports can ruin your day especially if you get a little yaw cranked in. Have been advised to use the (ungrooved) taxiways for this kind of thing, including run on landings and any other maneuvers where the helo may slide across the surface yawed from the direction of travel either as a result of poor technique or an emergency that doesnt readily permit a choice (possibly a hydraulics failure or tail rotor emergency).

[vaqueroaero]

EN48 - you are correct. The Bell practice area is a fine grain asphalt, made smoother by the fact that there have countless thousands of autos done to them which has in effect made even smoother. When I had my mishap with the skid shoe coming off it was on the grooved concrete taxiway at Alliance, which we were using because the practice area was iced over.

[MartinCh]

Anything with overhead throttles!
So, the instructor adds power on overhead quadrant while student/trainee focuses on collective/cyclic, in power recovery in Astar? Oh, and Euro MR rotation, ehm.

[newfieboy]

MartinCH,

Fuel control is on floor next to collective on Astar, unless you have twist grip option. Fleet I fly don't, so yep training pilot controls throttle....it's all good,just make sure ya don't pull throttle back too far....whoops if you do....:{ no idle stop. As for main rotor rotation on EC, after a while makes no diference. Our fleet consists Astar B2's BA, Bell Longrangers and 205, we often hop between a/c, don't have to think about the difference the blades are turning.....:ok:

[Shawn Coyle]

Unless the Polish folks changed it, the throttle in the SW-4 was in the overhead, making it a pretty sporting machine for an instructor to teach autorotations.

[MartinCh]

Thanks.
My bad. I remembered reading about helicopters that do not have standard twist grip throttle. AS350 and S76 were mentioned. Hence mistaking it or remembering the overhead quadrant.

[Gordy]

Found the pictures for my comments in Post # 10 (http://www.pprune.org/rotorheads/479191-bristow-academy-206-down-florida.html#post7070817) for what it is worth now:

You can clearly see the initial skid marks prior to the "jump"

http://i76.photobucket.com/albums/j35/helokat/Helo-general/DSCN0025-1.jpg

http://i76.photobucket.com/albums/j35/helokat/Helo-general/DSCN0023.jpg

http://i76.photobucket.com/albums/j35/helokat/Helo-general/mkcrash.jpg