I am not convinced - given the direction of the downwash..... delamination of TR ?

My flying career included virtually no experience of helicopters. I have followed this thread from the beginning. I cannot remember in the various lists of possible causes any suggestion of deliberate criminal action. Presumably, while the thought may not occur to Ppruners, there is an automatic forensic angle to the AAIB investigations.

The video of the departure taken from inside the stadium is pretty clear it didn't hit the structure of the building...
Anyway, what strikes me unusual is the puff of smoke from the engine as the rotor starts to turn....and vertical climb performance seems to deteriorate just before directional control is lost. Uncontained engine failure that severs the TR drive shaft?

I've just watched the video - it seems that something clearly wasn't right with that tail rotor.

Anyway, scary that I was dealing with Eric professionally by e-mail not too many months ago. RIP to all. :(

Extraneous Noise?
 

Could it have been a nearby car accidentally selecting reverse?

Yes, I'm sure you're right looking at it again. But this new clip does seem to go against the reports of odd noises or that the engine 'went quiet' before impact. The engine/rotor noise seems pretty constant....

Just had a quick scan on YouTube to find some previous AW109/AW169s departures from the stadium:

I found this one:
Although we shouldn't be making comparisons based on one video (especially as optical illusions could have their part too), the accident video shows the helicopter hovering for considerabably longer than the video above and it looks higher too.

Purely a very, very, very brief observation.

in the interest of further safety, thats not a bad thing is it?

That is an irresponsible thing to post.
We for sure do not know a, but one can guess at anything. For b, primary causal factor is TBD. C. Maybe, and maybe not, but Where Are You Getting Intentionally From? That, sir (or madam) is utterly Irresponsible.

Dear members of the media who may wander by here, none of that which anchor posted is supported by information, given the lack of same.

Anchor: you are jumping the gun a bit there. I'd recommend dropping the short attention span act and waiting for the first (of many) reports. They'll be arriving in due course. Whether or not your guesses are close, or far, from the actuality will in time be shown.

Quote:

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Originally Posted by GrayHorizonsHeli (Post 10297200)

in the interest of further safety, thats not a bad thing is it?

---

It is a bad thing if misinformation is spread by an instant, and wrong, answer. That's why fast isn't a good metric unless an early indication prompts the AIIB to issue an alert. Not jumping the gun is the AIIB being responsible, and doing their duty.

Regarding your idea of hitting something on the way in: what evidence are you pointing to that prompted that speculation?

Fortunately the reports will be based on professional examination of evidence, not a need to react to poorly motivated baseless trolling.

What got me to respond was the insinuation of intentionality. I do not feel that such ought to be left unchallenged. That, and me being aware of who may scan this site for tidbits to throw into a news story.

hmmm i dunno...a spiralling out of control helicopter that appears to not hit a thing on its departure??? something somewhere had to have happened. But again, I digress, could have just as easily been a sleepy mechanic not torquing the bolts correctly. I see lots of things on the pictures and videos that pique my interest. the could haves that may turn into the cause.
If you're so upset about musings by others, leave the thread and don't come back. clearly you're drawn here for a reason though....is it to try and start fights?

The accident investigators aren't special by any means either. they cast a wide net, rule out things as they go along in a structured way. Nothing different going on here at all except it's not so structured. They just put it onto a nice dossier in the end and publish it.

About your question regarding blindness (and/or disorientation ?)

As crab said, the pilot manages manually in attitude mode the Cat A take-off till the limits (height and IAS) to engage the modes are reached.

Anyway if you find yourself very early in deep disorientation troubles, WLVL is an attitude function that will level your wings and bring your pitch 6 degrees up.

​​​​​​To clarify, in case my post can be seen by anyone as any way ambiguous, I entirely agree with you.

Despite a couple of videos showing some aspects of the event pretty clearly, we still have people floating conjectures at odds with observable fact, such as fictitious collision with the stadium structure. If they haven't looked at the video themselves, they could at least believe those who have.

I saw a careful professional departure, with very good handling skills and no evidence of over pitching or disorientation. What did pique my interest on that last video was the moment of rotation after the vertical climb. A the moment the nose is pitched downward (and again, it was not overpitched or overcontrolled, but rather the transition initiated by someone with experience), there appeared the beginning of a right yaw that was briefly stopped after which the aircraft again accelerated the yaw to the right. Rate of descent afterward seemed high as well, higher than you'd expect from bottoming the collective to reduce the uncontrolled yaw. Definitely looking forward to the AAIB preliminary. Anybody know if the AW169 has real-time HUMS or how ofter it is downloaded?

As Malabo said this was a well flown departure all the way and one which I would expect from a professional pilot with experience. On this type of departure profile (confined area) flown from the RH seat you would yaw the a/c left to keep visual with the departure and possibly reject point in your chin bubble window. At TDP you would then yaw back to the right (30°) or so to straighten up. That's the procedure and that's what it looked like to me.

Thai opponents and a recent claim in the courts.
 

While reading the various press details about business opponents in Thailand, it reminded me of a crash in 2004 where a wealthy buisnessman with Russian connections died after the A109 he was in burst into flames and crashed while approaching Bournemouth Airport in 2004. Even the local MP was sceptical about the crash findings at the time.

The coroner confirmed that he was aware of the death threats against the businessman Mr Curtis who was the CEO of Menatep which was owned by the Russian oil company Yukos. Mr Curtis died along with his pilot.
The coroner stated at the time - "that it had all the ingredients of an espionage thriller!” There was a mention of a Russian connection at the time of the crash.
https://www.bournemouthecho.co.uk/ne...icopter_crash/

Re the press reports about the Thai businessman having opponents in Thailand. I noted in the article shown below, it reveals that last month a Thai court threw out a $430 million claim by the Airports of Thailand (AOT) regarding unpaid revenues by the Thai company King Power.
With the large amounts of involved, and the further mentions of opponents in Thailand, I wondered if anyone had a grudge against the chairman or his family?
https://www.today.ng/news/world/thai...y-owner-154035

More on the recent Thai court case.
https://www.yahoo.com/news/thailands...l?guccounter=1
Quote: "The license was secured from the state-owned Airports of Thailand (AOT) in 2006, after years of lobbying.
It gifts King Power the captive market of the near 40 million people expected to visit the country this year, many of whom trawl through its duty-free stores at Thailand's international airports or downtown mega-malls in Bangkok and Pattaya. Last month a court rejected an attempt to sue King Power for hundreds of millions of dollars in unpaid revenue to AoT.
That case was a rare pot shot by King Power's enemies. But without the shield provided by Vichai, the family could be vulnerable to avaricious rivals and moves to break up their monopoly.
"King Power's most important business is based on a monopolistic concessionary right granted by the government," explained Pavida Pananond, an academic at Thammasat Business School told AFP.
"That suggests the political nature of the business and Khun (honorific) Vichai's political and business clout.”
Whether his successors "move away from the 'know-who' to the 'know-how'" of the business will define how they parry potential competition, she said."

Other commentators have also discussed the Thai opponents, and the vast amounts of money involved.
https://thaipoliticalprisoners.wordp...ag/king-power/

Maybe one for the intelligence services, as the pilot was very experienced, and the aircraft was only two years old.. :suspect:

This all makes you think why bother these landings and take-off inside stadiums in general against having a helipad either on the roof or outside the bowl. Your are not in a good spot if something goes south, even if you are using a new high performance state of the art twin.

A YouTube of the crash footage, to avoid having to go to the tabloids:

Yep, I agree. But they seemed awfully high on the way up when things suddenly went pear shaped, given what I can make out of the height of the obstacles in the take-off path.

Tell us a good helipad that could have survived this accident at the rate of descent they experienced?

Turned the volume right up and couldn't hear any bang or grinding noise as reported by some eyewitnesses.
They may have heard main rotor blade slap and mistaken it for the sound of mechanical failure.
I assume a drive shaft can break or TR gearbox fail without any audible sound at that distance.
Chilling video to watch.

In the very beginning of the video, is that just a puff of condensation when they start?

Perhaps he increased his TDP height on departure because it was at night, in order to compensate for the light into dark scenario and to give him a better chance of flyaway (ironically).

I don't understand. Just watched the video. The aircraft is rotating clockwise (viewed from above). Surely that's the SAME as the rotor rotation? Or does the 139 have US-style anti-clockwise rotor?

As a medium-time PPL-H I've thought a lot about this accident (like everyone else :-( ). I guess if you lose the TR at low altitude like this, you're pointing where you're pointing (even if you bring the yaw under control) and going where you're going. At altitude you can turn with cyclic, but no time for that here. So unless you have exceptionally good luck, it's not going to end well.

n5296s - you need speed to retain directional control without the TR and, if you haven't got any speed, you need a lot of height to dive on that speed - he had neither!

If you have ever seen the video of the Wessex going into a Welsh lake many years ago - a colleague of mine was flying it and he had the failure at 60 kts and 1000' - he still ended up in a horrendous spiral descent.

jumpseater - I'd be very surprised if it was disorientation but less surprised if it was a medical issue.

I hesitate to say this, but if it is a TR Drive/Low power Hard over, he seems to take a long time to react. Many rotations under near hover power before the descent takes place.

CRAB in the Wessex event, did he keep the power on and cushion into the lake?

I was an RAF Engineer Officer involved at the periphery of the Wessex crash.

Attached below is the summary of the accident report.

There are several Youtube videos, just search 'llyn padarn helicopter crash' (I'm too new to post a link here).

What material are the tail rotor blades made from?

Preparing for the worst
 

When teaching TR Fail (drive fail or worse) in the 139 sim I first caution the candidates about taking care not to take too much detail away with them after this exercise - the sim cannot be relied upon to truly replicate the real event. In any case, as the UK CAA research has shown, there are a variety of failure modes that result in loss of directional control. There are, however, one or two elements of the training that are worthy of remembering and putting to good use in the event that you do suffer the loss of directional control and it applies throughout the flight phases - take-off, transition and cruise. That vital action is to quickly lower the collective fully. The second vital action is to close down the engines if in transition to facilitate a pitch-pull prior to ground contact. Failure to do this will result in making the situation worse during the 'arrival' at terra firma. In the cruise, you have more options provided you have been quick enough lowering the collective and are not spinning. It's possible to make use of the engine power to reduce RoD if required but by 500 ft the engines should be off. We see a perfect application of these principles when a 139 threw a blade in Macau. It works, but your reaction has to be instantaneous and to condition yourself for such a horrific event you need to practice - a number of times - in a good quality Full FLight Sim. If the loss of directional control occurs in the hover just lower the collective immediately an close down the engines after you are safely down.
G