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-   -   AW169 Rollover (https://www.pprune.org/rotorheads/639524-aw169-rollover.html)

helicrazi 29th Mar 2021 20:40


Originally Posted by etudiant (Post 11018806)
Think recent accidents in Alaska, earlier in France, the Caribbean and before that a UK stadium, all billionaires, wiped out by their helicopters

But this wasnt a privately owned helicopter with a crew being paid by HNW individual. Wealth has nothing to do with it.

PlasticCabDriver 29th Mar 2021 20:57


Originally Posted by ShyTorque (Post 11018271)
It used to be part of the RAF Puma conversion course how to learn how “drive” the aircraft forwards out of the situation where the nose wheel had accidentally become fully cocked off to the side. The first part of that recovery was to centralise the yaw pedals to avoid the aircraft rotating uncontrollably, and use the independent main wheel brakes to help stabilise and steer, rather than big bootfulls of pedal. It was important to get this right, due to the high mounted tail rotor the Puma will roll very rapidly and markedly if too much pedal is used on the ground].

and was even more fun to teach from the LHS when only the RHS had brakes!

etudiant 29th Mar 2021 21:52


Originally Posted by helicrazi (Post 11018811)
But this wasnt a privately owned helicopter with a crew being paid by HNW individual. Wealth has nothing to do with it.

Exactly, seems a very touchy device even with a fully professional crew.
Something that zillionaires chose to ignore at their peril.

ShyTorque 29th Mar 2021 23:20


Originally Posted by PlasticCabDriver (Post 11018819)
and was even more fun to teach from the LHS when only the RHS had brakes!

Indeed it was. Along with the other dirty little tricks that type could play on an inattentive pilot! Turmo engines without anticipators backing right off then being very slow to catch up next time they were needed, in flight Y/R divergence and “wrong pedal” takeoffs, BARALT hold dropping out below 80kts and the aircraft wanting to surreptitiously go into a descent, etc.

ZAGORFLY 30th Mar 2021 04:29

3 entire left rotation did not prompt the pilot to counteract with right pedal ? Nor down collective and close the throttle?these are memory items! BTW Leonardo why an helicopter need a wheel lock in first place?
did the pilot checked free of movements of all the controls before takeoff? maybe not. Embarrassing.

Originally Posted by malabo (Post 11017649)
The AAIU has already determined it was not the crew’s fault. The pilot was licensed and qualified by the authority and followed the published SOP to the letter, nobody to blame.

But even less seriously...looks like he wanted to taxi to the left, aircraft resisted so he tried a little harder, then remembered the nosewheel lock and when it released the aircraft spun left with full left pedal applied. This threw the pilot to the right still hanging on to the cyclic and collective. So on top of the yaw the pilot has now got the collective coming up and full right cyclic. The aircraft is truly embarrassed at the overreaction by the pilot to the initial slow left turn and rolls over in shame.

fodder for weeks to come on pprune


monkey_see 30th Mar 2021 06:12


Originally Posted by etudiant (Post 11018792)
Can only say 'Oh wow!'.
An aircraft in perfect shape, destroyed in seconds because of the nose wheel not being unlocked in time?
If this is representative of the sensitivity of helicopter flying, it explains a lot.
The question that remains is why do very wealthy people accept such low safety standards.

An aircraft in perfect shape destroyed in seconds because more or less full left pedal is applied on ground.
I have never flown a plane but somehow I am sure not following the RFM and SOPs is a path to wreck a perfect airplane as well.
This has nothing to do with low safety standards. Planes crash all the time as well. Already forgotten the 737 Max?

hargreaves99 30th Mar 2021 06:49

i assume checking the nosewheel lock is off/out is part of a pre-landing checklist?

helicrazi 30th Mar 2021 06:57


Originally Posted by hargreaves99 (Post 11018974)
i assume checking the nosewheel lock is off/out is part of a pre-landing checklist?

In this situation, it's in the pre taxi checks, which it's being assumed, were missed.

Flying Bull 30th Mar 2021 07:07


Originally Posted by ZAGORFLY (Post 11018934)
3 entire left rotation did not prompt the pilot to counteract with right pedal ? Nor down collective and close the throttle?these are memory items! BTW Leonardo why an helicopter need a wheel lock in first place?
did the pilot checked free of movements of all the controls before takeoff? maybe not. Embarrassing.

Well,
there is some information, we don’t have yet
ie who pressed the unlock switch?
Could have been without proper crew coordination and caught out the pilot by surprise (not excusing the inputs already applied and not reducing them when coming to a stop for error analysis)
You have to be 100% there to react fast enough- or you turn into a passenger in a matter of seconds.

About the need of nose wheel locks - yes, you need them, when you do a fast run on landing, ie with a tailrotor malfunction.
You can see on the accident video, how much torque could be counteracted with a locked wheel- excactly what you want in case of tailrotor emergencies.

Full and free movement of controls won’t test the nose wheel, its freely rotating - if not locked

Reely340 30th Mar 2021 08:40


Originally Posted by ShyTorque (Post 11018868)
Indeed it was. Along with the other dirty little tricks that type could play on an inattentive pilot! Turmo engines without anticipators backing right off then being very slow to catch up next time they were needed, in flight Y/R divergence and “wrong pedal” takeoffs, BARALT hold dropping out below 80kts and the aircraft wanting to surreptitiously go into a descent, etc.

Damn, you are talking about a design from 2012 correct? :confused:

Even 60 years old S300Cs have peerless throttle correlators (no closed loop, but working very fine).

How can BARALT hold drop out except for clogged static port? :bored:
I can understand that RADALT can do funny thing when over water or crossing a dropoff,
but BARALT hold should be super reliable, except maybe when close to mining explosion with noticeable shock wave.

And what is a "wrong pedal takeoff" in an AW169 ?
Its MR turn Bell-style, so even non-metric pilots from overseas should feel at home.

Bravo73 30th Mar 2021 08:53


Originally Posted by Reely340 (Post 11019039)
Damn, you are talking about a design from 2012 correct? :confused:

No. He's talking about the original SA330 Puma, first designed in the early 1960s.

[email protected] 30th Mar 2021 09:08


No. He's talking about the original SA330 Puma, first designed in the early 1960s.
which had a rather late 'mid-life' upgrade and will be scrapped by 2025.

The Pumas were notorious for their lack of anticipators and the crewman would loiter between the seats to call the Ng/N1 above 75% - below that, at large application of collective would droop the Nr and drop the electrics and AP off line ISTR.

etudiant 30th Mar 2021 13:01


Originally Posted by monkey_see (Post 11018955)
An aircraft in perfect shape destroyed in seconds because more or less full left pedal is applied on ground.
I have never flown a plane but somehow I am sure not following the RFM and SOPs is a path to wreck a perfect airplane as well.
This has nothing to do with low safety standards. Planes crash all the time as well. Already forgotten the 737 Max?

Well, perhaps the analog is the A-340 crew destroying a brand new aircraft by running up the engines without wheel chocks. (https://www.snopes.com/fact-check/etihad-a340-accident/)
Still is very sobering to see how fast things can go pear shaped.

Reely340 30th Mar 2021 13:03


Originally Posted by Bravo73 (Post 11019050)
No. He's talking about the original SA330 Puma, first designed in the early 1960s.

Pheeew, that is reassuring. thx

ShyTorque 30th Mar 2021 13:22


Originally Posted by Bravo73 (Post 11019050)
No. He's talking about the original SA330 Puma, first designed in the early 1960s.

Correct! As I joined the RAF Puma fleet (over 40 years ago), I was handed a formal Flight Appraisal report written by a Boscombe Down test pilot. It mentioned the issues I included and the conclusion was along the lines of “until these design faults are corrected, this aircraft should not be accepted into service.”

Anyway, as we approach the Puma’s 50th anniversary in RAF service.....at least they fitted decent engines a decade or so ago. :D



sycamore 30th Mar 2021 14:28

The list was a lot longer than that ,Shy.......!

ZAGORFLY 31st Mar 2021 04:37


Originally Posted by helicrazi (Post 11018803)
This wasnt uncommanded, it was commanded, and as soon as they realised they had forgotten the nosewheel lock and unlocked it (the amber flashing lights in the sim) they got the yaw they commanded.

and wait 3 turns before realizing that some thing was wrong? Wait two entire 360 before apply right pedal and kill the torque by lowering the collective? I don’t think so. The rudder was jammed. Btw if I will buy that helicopter I will request skids !...

Flying Bull 31st Mar 2021 05:54


Originally Posted by ZAGORFLY (Post 11019607)
and wait 3 turns before realizing that some thing was wrong? Wait two entire 360 before apply right pedal and kill the torque by lowering the collective? I don’t think so. The rudder was jammed. Btw if I will buy that helicopter I will request skids !...

sorry Zagorfly,
you are showing, that you have no clue about what went on and which forces are working.
First mistake was not to unlock before starting to roll
second mistake was to increase pedal and collective, when the intended turn didn’t work - you can see the helicopter already tilting, which feels extremly odd and should make one uneasy...
third mistake was stopping with brakes instead of lowering the collective first - still torque applied
fourth mistake was to unlock the nose wheel in that configuration
and you think a pilot, not knowing what he did the whole time will be quick enough in his reactions and able to overcome the centrifugal forces after the first turn?
He needed to dump the collective within the first 90 to 180 degrees, if there ought to be a chance of recovery- after that he is only a passenger...

helicrazi 31st Mar 2021 06:28


Originally Posted by ZAGORFLY (Post 11019607)
and wait 3 turns before realizing that some thing was wrong? Wait two entire 360 before apply right pedal and kill the torque by lowering the collective? I don’t think so. The rudder was jammed. Btw if I will buy that helicopter I will request skids !...

And this is the problem with pprune :rolleyes:

[email protected] 31st Mar 2021 07:09

I've flown two aircraft with lockable tailwheels (Wessex and Sea King) and two with lockable nosewheels (AS365 and AW 139) and they all need a little wiggle on the yaw pedals moving forward slowly to ensure the pin comes out and the wheel is unlocked - not a great bootfull of pedal like this guy did.

If it doesn't unlock, lower the collective, check the handle/selector and then try again - gently!

Just very poor piloting.


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