PPRuNe Forums

PPRuNe Forums (https://www.pprune.org/)
-   Rotorheads (https://www.pprune.org/rotorheads-23/)
-   -   Ch 10 chopper crash, Perth (https://www.pprune.org/rotorheads/505650-ch-10-chopper-crash-perth.html)

John Eacott 21st Jan 2013 00:32

Some better footage: the reactions of the emergency services is commendable, police running to assist, firies prepping the truck to move closer, etc. Accounts say the turbine wasn't shut down following the crash, easily done in the haste to evacuate. Glad both crew are well :ok:






gulliBell 21st Jan 2013 00:51

The owner of the company was interviewed on CH7 news last night and from what I understand he said it was an engine failure, and through training and skill of the pilot to get the helicopter on the ground whilst avoiding the power line and various other obstacles in the way. It was only because of the unsuitable terrain that the aircraft rolled over.

From the audio it sounds to me as if the rotor rpm was rapidly decaying just prior to impact, and the engine kept running at idle after impact. But from the video taken from the helicopter it is quite evidently rotating rapidly to the right and descending almost vertically, which to me is symptomatic of a sudden onset loss of directional control at low airspeed.

What got my attention is the violence of the roll-over after the helicopter made contact with the ground, and the main rotor departing the scene, which together with the relative un-crash-worthiness design of the B206 (particularly the seats), makes the relative lack of injuries sustained by those on-board quite remarkable. Very lucky...

BTW I think this is the 3rd prang for Ch10 since they have been operating a helicopter from Dianella (VH-AZH and VH-AZN?, but under a different operator). I don't recall Ch7 or Ch9 having an accident before.

chopjock 21st Jan 2013 11:26

Engine failure? Oh it's the southern hemisphere so the nose rotates to the right in that case.:8

Tickle 22nd Jan 2013 01:32

Seven had an LTE incident in a JetRanger in the 1980s. The pilot managed to set down in a clearing. It was caught on tape from the onboard cameraman. Not sure where it happened.

mickjoebill 23rd Jan 2013 10:48

There is an aching gap between the reality of the comparative risks to aerial camera crew and how it is percieved by media managers and even the helicopter industry itself.
For example, there is a glossy online promotional saftey poster showing a R44 very low over the water, doors off, shooting a boat, the image taken by a photographer in the back seat. Its a dynamic image. Not sure if the R44 was fitted with floats.

So we have a stills photographer in the back and cameraman in the front seat with a large camera on his shoulder. The cameraman is photographed in jeans and T shirt with a life vest. He is without helmet or flight suit. The shoulder seat belt is ineffective as he has rotated his torso to shoot out the door.

On a risk matrix there is a "severe consequence" if either the camera slipped off the shoulder (due to the life vest ) or the fouling flight controls in changing battery ect.

The text on the poster states "Work safe, Fly safe, Fly xxxxx" :eek:


Mickjoebill

gulliBell 23rd Jan 2013 11:16

An R22 crashed into the sea off Rottnest many years ago doing exactly the same thing....

topendtorque 25th Jan 2013 20:47


There is an aching gap between the reality of the comparative risks to aerial camera crew and how it is percieved by media managers and even the helicopter industry itself.
Nailed that one.Especially junior pilot hour sharks out there to do what they think is an easy job.

I think I notice in the last video how there is a sudden jerk to the left in the camera frame immediately prior to the rapidly increasing right rotation.

That might indicate the Tail area running into something which impeded it's movement just prior to the rotation.

There is nothing unusual about the rotation to the right in a "normal" helicopter whose M/R turns in the correct sense, (ahem) and certainly nothing unusual about the severity of rotation when a T/R drive fails.

Been there done that, leaves yer false teeth and glasses and head behind while yer body has gone over there. The only remedy at that height - snap the throttle closed and right now sah.

rachbuzz 26th Jan 2013 03:19

Mickjoebill

CASA doesnt investigate air crashes - the ATSB does and makes safety recommendations to CASA through its final report. CASA can choose to act on the recommendations of the ATSB or not.

army_av8r 26th Jan 2013 13:52

certainly has the tell tale look of an LTE incident, unless of course it was a tail rotor mechanical failure. at that altitude it really doesnt make a difference what the cause of the right yaw is... keep the ship level, full left pedal, get some forward speed and if that doesnt help, chop it and go for the dirt! unfortunately it looks like the skids hit a pretty good slope and bounced it down hill. i would be curious to know the wind direction, velocity and temp/DA that day.

topendtorque 27th Jan 2013 01:37

Army--

Very hard to image a qualified flight instructor being caught with LTE, although which version do you refer to?

1) Run out pedal effect rotation, commences relatively slowly, and is allowed to continue unchecked by useless driver.There is at least one recorded accident thus, in the City to Surf run in Sydney many moons ago. It was a quite heavily loaded 206.
An instructor caught in that? doubt it.
Also the rather light loading of this machine even in high risk ambient conditions should render the condition unlikely.

2) T/R encounters M/R vortices and generates its own VRS and snaps away from behind you to beside you at the same speed of light that a T/R drive failure will generate.Under that scenario it will then slow its rotation as it continues to a position in front of you, as it has encountered different relative wind conditions, as in any VRS recovery.
Once again hard to imagine a flight instructor losing it at that point.even without specific simulated training.

Whereas a drive shaft failure will result in spatial orientation difficulty after the second revolution, but at that point the throttle can be snapped and cyclic steerage maintained to a degree. Your choices are limited to what is below you and arriving at ground level with sufficient cushioning RRPM is another matter but possible under various scenarios.

In this case there does appear to be some little distance between T/R failure A/C position and ground contact. It's fairly easy to imagine the driver keeping the collective up just a little longer than he should (for a bumpless landing) and steering the machine over the ground parties to whatever was beyond. If that was the case then the driver deserves great credit. This decision may have been helped by the awareness of the power lines or bumped obstacle behind him.I.E. something else to get away from.

As far as I am aware simulation training for this event is not part of the syllabus and should be at least at the first BFR. It's not for the faint hearted and should not be commenced below 1200 feet AGL and a readiness for aborting it with left pedal input, must be contemplated if the aircraft appears to want to become inverted.

gulliBell 27th Jan 2013 04:57

...whatever the reason (LTE or mechanical), the fact remains that the aircraft was being flown low and slow with a door open and in that environment even with 8/8 of flat level ground all around, the prospect of pulling off a forced landing without damaging the aircraft is very remote. The fact that the crew pulled it off without damaging themselves, despite writing off the aircraft, is testament to either luck, exceptional skill, or more likely a combination of both.

But I do ask myself, is it worth the risk exposing yourself to that hazardous environment where the reward is just a 5 second grab on the nightly news? I think not. Much better to give yourself some height, give yourself some airspeed, and remotely point a gyro-stabilized gimbal mounted camera at whatever it is you need a 5 second video grab of. A news cameraman hanging out the door of a single engine helicopter at low level is so 1970's...there is a better and safer way of getting the job done, and that requires some investment in the proper hardware.

topendtorque 27th Jan 2013 11:39

Can't argue with that viewpoint Gullibell, the cost of new gadgets might frighten a slacko, but the rewards for those with initiative and well thought out budgets must be immense and they should soon leave those tired old ways in the dust I hope.

Stamping out dispos to operate out of the door on a lanyard would be a very good start.

army_av8r 27th Jan 2013 14:55

Topend, my thought was main rotor vortex interference with the tail rotor, or situation 2 that you mentioned. I certainly dont think he was "unprofessional" if he got caught out with LTE. I have put myself in those positions quite a few times as a result of "getting the mission done". fortunately the OH-58D doesnt spin up quite like its B-206 brother. obviously if something broke back there, then none of what im saying matters. just a reminder that low/ slow in a 206 requires very precise heading control and once it lets go, it can spin up quick. and unless you know its LTE based on conditions, it can be hard to diagnose before your on the ground.

2leftskids 1st Aug 2013 06:56

Accident report
 
Investigation: AO-2013-016 - Loss of control and forced landing involving Bell 206B3 helicopter, VH-ZMN, 18 km north-east of Perth Airport, Western Australia, 19 January 2013

John R81 1st Aug 2013 12:09

And the prize goes to......

Floppywing, post 12


Should we start scoring people's guesses as to cause and add that to their profile so it shows to the left of your post? Wouldn't that be interesting and informative for all uf us reading seculations as to cause of incidnets!

AnFI 1st Aug 2013 17:46

LTE again?
 
"......is a challenging task with an inherent risk of LTE"

the Lack of Tailrotor Education was present before takeoff

it is not the same as Lack of Tailrotor Effectiveness - no helicopter has a problem once faced back 'into wind' at (airspeed) 30kts - Shirley?

If a helicopter doesn't want to yaw 'out of wind' then let it align with the airflow ... simples

Even if it has to go around once before you work it out don't panic ....

mickjoebill 2nd Aug 2013 13:29

Good to see helmets and flight suites are being adopted.

By my reckoning excluding the mid air collision between news choppers, survivability of cameramen when shooting hand held with door open is very poor compared to an accident involving a stabilised mount.

Around 18% of accidents when stabilised camera is in use are fatal to cameramen, but >50% of accidents when hand held or door open shooting is taking place are fatal to cameraman!

Also incidence of accidents with doors open is double that of stabilised.


Mickjoebill

infloweffect 3rd Aug 2013 05:53

A timely reminder to all 206 drivers young or old. DO NOT Initiate a Level RIGHT pedal turn in a Bell 206 with low airspeed and light winds. Filming usually involves right hand orbits with the camera man on the pilots side with door removed. The pilot makes the mistake of entering a right turn with right pedal to prevent the rotor tilting into the camera shot. Do this and risk LTE. Always lower the collective before initiation of the right turn. This causes the main rotor vortex to rise above the plane of the tail rotor in relation to the helicopters movement downwards. It is not in any txt book or training manual i have ever read but i know it works. Even pilots with many thousands of hours in the 206 can be caught with LTE. If power is available this technique also works with a gentle climb. I have flown the 206 on many film jobs throughout my career. Most instructors or CP's don't know or teach this life saving technique. LTE is demonstrated to take at least 300 feet to recover from a test pilot knowing what is about to happen. If you get LTE you must apply full left pedal and hold that until rotation stops and airspeed is restored. If you are below 300 AGL your in a world of hurt. You may need to close the throttle to stop rotation. Not where you want to be at 300 feet.

mickjoebill 4th Aug 2013 04:32

Very similar to this one.
Ex-military pilot of this TV spinner say he had no training in LTE.

www.aaiu.ie/sites/default/files/upload/general/12835-REPORT_2004_021-0.PDF


Mickjoebill

[email protected] 4th Aug 2013 05:01

Inflow - far better to keep the speed up when turning downwind (in both these incidents, low speed was the issue) or you end up descending downwind with low speed, putting you more at risk of VRS than LTE. It's an old problem of flying orbits around a fixed point on the ground - the pilot is target-fixated and flys a constant groundspeed instead of airspeed. Loss of translational lift and the tendency to weathercock add to the mix and bingo! All aggravated by certain designs without sufficiently powerful TRs!


All times are GMT. The time now is 09:47.


Copyright © 2024 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.