French Lighthouse Ops incident, 6 July 2022

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However, there is no definitive answer since we weren't there and don't have any evidence to prove or disprove any assertions - probability would suggest oil in the exhaust but that is only a slightly more educated guess than the floats/powder/nitrogen guess

[Rotorbee]

Crab, I am glad you are back to your old self. After the post were you gave in I almost wanted to write: Who are you and what have you done with the real crab. Thank god the world is normal again.
Anyway, have any of your talcum powder fans ever changed diapers on a real baby? That stuff does not act as a smoke cloud and you would need kilos of the stuff and something that blows it around to create some sort of cloud (think powder fire extinguisher). Believe me, I have tried to make clouds out of any powder available (my mother wasn't amused) through all my childhood. It never looked really like a cloud.
The nitrogen isn't an option to blow the talcum like in the video, because it flows INTO the floats. Outside it wouldn't help a lot.
Please watch the following video. It's of a A119 and you will see there is nowhere enough "smoke". And with the wind blowing and the airflow over it, the powder just blows away and disappears in no time, as you can see in the lighthouse video when the floats finally pop. Well you can't see anything and that's the whole point. BTW, the A119 floats pop way faster than the H125 one's.

Video A119

[[email protected]]

Rotorbee - thanks for your concern

However, your video clearly shows a cloud of powder as the floats inflate - discuss.

Equally there is always overpressure from the nitrogen bottles to ensure a rapid inflation - the excess is vented and cold nitrogen escaping and expanding into warm moist air will create a cloud.

Yes, it probably is still oil but I will bow to public opinion.

[megan]

Could be talcum powder out of the exhaust.

You Tube

[Encyclo]

All explained here:

You Tube

Fly Safe, Always

[Rotorbee]

Ok, we know now what happened, but the smoke was not mentioned. So, we can go on.
Yes crab, there is baby powder in this video, but it is way less than the smoke that came from that helicopter in the original video.
Common, don't give up to the public opinion. Often public opinion is way off from the truth. Incident analysis is not a democratic process.

[Agile]

As I reviewed this video below from a TV heli in LA
it really looks like oil smoke, dense and white
the talc power smoke was difuse and grey

You Tube

[krypton_john]

It was actually brown "smoke" coming out of the pilot's arse, that appears white because of the sun reflecting of droplets of moisture in said brown "smoke"

[[email protected]]

As I reviewed this video below from a TV heli in LA
it really looks like oil smoke, dense and white
the talc power smoke was difuse and grey

But that smoke in the LA video isn't coming from the exhaust, even though it looks from some angles that it is. It is pouring out of the engine bay.

And it isn't there for a couple of seconds either - just sayin'

[Nubian]

Originally Posted by [email protected]

But that smoke in the LA video isn't coming from the exhaust, even though it looks from some angles that it is. It is pouring out of the engine bay.

And it isn't there for a couple of seconds either - just sayin'

Flogging a dead horse Crab!
The video is for indication as to what an oil-leak on a hot engine looks like.
I’ve tried to explain to you how this can happen on a healthy machine without a leak, but you choose to ignore that.
The smoke in the video brings back memories as it is very similar to what I experienced with the R22, and I repeat, it was only drops onto the hot exhaust that produced my cloud.

You, on the other hand haven’t answered my questions.

By the way, ASN has been edited I can see. Wonder why?!

[[email protected]]

Rather an aggressive reply again Nubian, sadly all too common on social media nowadays.

I don't have my AS 350 notes to hand but ISTR there is a centrifugal filter in the scavenge side of the oil system that separates the returning oil and only passes excess vapour to the exhaust via a pipe which vents into the exhaust stream and not onto the exhaust itself - I find it unlikely that a glob of neat oil could find its way back through that system to the exhaust.

I'm quite content what an oil leak on a hot engine looks like - are you sure that LA video isn't a hyd leak or a fire?

As to your question - there is powder in the bags when packed - Rotorbees video clearly shows that. Is there enough to create such a big cloud? Maybe not but if excess was put in by error it might be possible.

As I mentioned above, there is always overpressure from the nitrogen bottles to ensure a rapid inflation - that overpressure has to go somewhere - you can hear it escaping from vents after inflation (the same happens on survival dinghies).

There may even have been a leak in the feed from the bottles to the bags.

[[email protected]]

As to the ASN - I refer you to your previous comment

Edit
Missed your reference to the Wikipedia of accident reporting. I read a lot of those listings, but as whoever can contribute their more or less accurate information, I take the info with a slight pinch of salt. In this case, a rather large one…..reading the rest on ASN. This info might come from this very thread in the first place, like the media has been collecting “facts” before…

[Rotorbee]

As I mentioned above, there is always overpressure from the nitrogen bottles to ensure a rapid inflation - that overpressure has to go somewhere - you can hear it escaping from vents after inflation (the same happens on survival dinghies).

The smoke came before inflation ... do I have to say more? And before any venting could happen. Do I have to say even more?
The nitrogen is stored under pressure in this case, not as a liquid. As a liquid you don't store it under pressure. You definitely don't want liquid nitrogen flowing into rubber bags and I am not even talking about valves and seals. That would not end well. Even if it vents out, you may see a bit of fog in the stream of nitrogen, because vapour in the air will condense around the now cooler nitrogen, but not like that. Liquid nitrogen boils at 77K. You will have a hard time to cool nitrogen to 77K only by expanding it. The pressure in the bottle would be way more than necessary, given the size of the bottles, and very very dangerous.

[Nubian]

Originally Posted by [email protected]

Rather an aggressive reply again Nubian, sadly all too common on social media nowadays.

I find it unlikely that a glob of neat oil could find its way back through that system to the exhaust.

Pretty thin skinned then Crab, if you take my last post as aggressive. I’ll take that into considerations later.

The neat oil you’re finding unlikely to find its way back, will be coming from the reservoir as it circulates back. In a low G/negative G situation there is a couple og litres pushed to the top of the tank, and the vent line has no valve restricting flow out to the exhaust pipe.

[[email protected]]

Not thin skinned, I just dislike rudeness.

I don't think you can assume there was negative g, he pushed forward sure, but the reduction in g would have been very little - note that the smoke comes during the recovery as he pulls power - no negative there

[Rotorbee]

Crab, he did not push forward, he was pulled by the line. In that case all bets are off, because that wasn't aerodynamics alone. That yank at the helicopter could have caused the oil flow into the exhaust. And give it a bit of time to evaporate. Fire would have been faster for sure, but a gush of oil might take a while.

[[email protected]]

Crab, he did not push forward, he was pulled by the line.

Agreed but he was moving very slowly and the aircraft almost pivots in space - is that enough to push oil around in such a manner as to get it to the exhaust? I don't know.

He then keeps the nose down to gain airspeed before pulling out hard which is where the smoke appears - co-incidentally or not with the inflation of the floats.

We are still speculating about the cause simply from the video which may or may not be definitive.

[Rotorbee]

Crab, how the helicopter moved in space was entirely defined by the line until it broke. Since we do not know when that happened, we can only speculate. From what I see, I suppose he was pushed forward and to the side by the gust and then the line got stretched and that what caused it to pitch over and roll. The turning point would be the belly hook (more or less). That would make the helicopter go nose down without loosing much of altitude. The engine would be quite far from the turning point, moving in an arc and therefore could get enough minus g's for the oil to flow to the vent. At that moment the line probably broke, when the load was pulled to the railing. Unfortunately injuring a person. All that time the pilot probably tried to stop the movement with aft and left cyclic - not much else he could do - which would explain the pretty quick recovery.
That's my theory.
But in a few short years, there will be a report.
And right now the French have a new hero. Best helicopter pilot ever. No other country makes them like that. And only a French helicopter could make it. According to the French video, the pilot was cold blooded. An alien lizard person probably. On an exchange tour.

[[email protected]]

Rotorbee - I think your analysis and theory are viable As you say the report will come along at some stage.

And right now the French have a new hero. Best helicopter pilot ever. No other country makes them like that. And only a French helicopter could make it. According to the French video, the pilot was cold blooded. An alien lizard person probably. On an exchange tour.

that did make me chuckle

[Nubian]

Originally Posted by Rotorbee

That yank at the helicopter could have caused the oil flow into the exhaust. And give it a bit of time to evaporate. Fire would have been faster for sure, but a gush of oil might take a while.

My point all along…