Megan - I'm not saying some oil doesn't get to the exhaust, the vent is designed to push excess oil vapour out into it to be burnt off - but that amount of smoke would need a huge amount of oil (not just vapour) to be pushed out and the amount of negative g required to do that just doesn't seem evident from that video.

Quite - not always recognised. I have contributed to one entry directly, and seen narrative in the same incident that came from a post I made on Pprune!

The video of the AS350 ditching into the East River in 2018, does not show the same evidence of 'chalk' after float deployment.

It would take sackfulls of chalk to make a cloud as big as that, apart from which it is plain to see that it is streaming from the exhaust, not just appeared in one big puff from underneath the fuselage.
How much white smoke do you get in a flameout relit by the auto-igniter? Airflow into the intake must have been pretty chaotic at the start of that manoeuvre. I'd guess there would be some?

Do we have a new pope?

^ ^ ^ ^ ^ ^ ^ ^ ^
+1 to the above (meleagertoo). And to all the others who realised it was engine related and emitted from the exhaust.

It couldn't possibly have originated at the floats then magically be jetted directly out of the exhaust!

Just the typical reply from you when your bias is questioned.

As you ask this way, I’ll ask you to explain exactly how much powder needed for this cloud to form, or how much nitrogen would be needed? And more importantly how it can escape the system and yet fill the floats normally?

As to how much oil needed, I know that a very small amount of oil in/on the exhaust produce lots of smoke. I lost about 4 quarts of oil when a oil cooler blew in my early days in a R22. Only a few ml’s in the landing phase, but as it was dripping onto the exhaust pipe it produced quite an impressive amount of smoke, we are talking about drops.

But hey, you’re the expert…..!

In order to have auto-relight in the B3, you need to recycle the startswitch and even the newest model require 1000ft Agl to do it safely, the old models 2000ft. And looking at the video, I’d like to shake the pilots hand, capable to recycle that switch during this manoeuvre….. let me know where I can find him, maybe in the UK?!🤔

Looks like a labyrinth seal failure - briefly - had one on another aircraft and it's produces a massive white cloud. I can imagine the abrupt change in power could reduce the engine internal pressure and defeat the labyrinth seal briefly allow pressurised oil straight into the exhaust.

A lot of debate over the source of the smoke (or whatever), but I join the crowd who consider it to be from the exhaust (for whatever reason). The floats inflate a fair bit afterwards, first starboard side and then (still later) port side. I remember some footage on YouTube years back of a US media helicopter making an emergency landing in a carpark while being filmed by another helo. It also released a hell of a lot of smoke, but not just for such a short time, rather all the way to the ground and after safe touchdown. The motion of the helicopter as it descends in this case looks somewhat irregular almost as if it is being acted on by a sling line under tension at some stages?? I have seen RC helicopters 'thrown around" like this, but never realised a full sized helicopter could also react this swiftly.

rather a snarky reply but if most think it is oil in the exhaust then I'll just agree to disagree until someone can explain how a lot of oil gets there and for only a short period before returning to 'normal' running..

I suggested the float gear and the nitrogen as a possible explanation without analysing the video frame by frame - it is also possible it was neither that nor the oil in the exhaust.

JOKE
“It should be obvious to all that what we are witnessing is the first known successful operational deployment of. the secret “Auto Smoke Crash Position Indicator” ASCPI. (TM protected, patent pending)
FROM the RFM ASCPI Supplement : “Anytime the system detects the following conditions : more than -1.5 G and a attitude of +75 Degree’s nose down and a VSI of -1000 FPM at less than 120 ft. Rad Alt, Engine oil is injected into the exhaust by the ASCPI system. This creates a large smoke cloud to indicate a Position Datum Point at which to initiate Recovery Operations.
If the float system is “Armed” for overwater operations activation of the ASCPI will also activate float deployment thus aiding in debris recovery.”
JOKE OVER.

I’m just glad nobody was killed or seriously injured during this event.

I watched it a bit closer. The smoke starts while descending, the floats pop while climbing again. Quite a bit of time in between. The smoke stopped pretty quickly after regaining a normal attitude. The smoke looks like it is above the tail boom. If that much smoke would be produced by popping the floats, we would never have tested them inside the hangar. My bet is on the engine, not the floats. And one does not need a lot of oil to produce a lot of smoke.
In that situation I can see myself easily popping the floats, just in case.

Here's the first frame when the smoke appears.

https://cimg1.ibsrv.net/gimg/pprune....250825e5ad.jpg

The smoke ending, looks like coming from the exhaust.
https://cimg3.ibsrv.net/gimg/pprune....79855de643.jpg

First frame of the floats inflating.
https://cimg4.ibsrv.net/gimg/pprune....8100693a92.jpg

Snarky or not, I'll try to explain.


There is always some pressure in the return oil to the tank, which is necessary to vent off from the reservoir to prevent pressure increase in the system which in turn would push the oil through the engine where it will be burned and empty your reservoir in a fairly short time (which a clogged breather line will do)

As you have air in the top part of the reservoir in normal conditions, only the vapours are being vented off. An abrupt uncontrolled manoeuvre like in the video (possible caused by a pull from the external load), the oil will end up in the top of the tank where the breather line is attached and the pressure in the return will push the oil out instead of the vapours.
As the manoeuvre is back to normal with positive G's, the oil stop being vented overboard and the smokes stops..... as I said earlier, it does not need to be a lot of oil to produce this amount of smoke.

Solved!

The Chemtrails reservoir self-void function deployed as the computer only assessed a crash as 'likely'.
It's clear that it didn't assess the crash risk as 'imminent' or as we all know the pyro-charge would have fired to incinerate the agent which creates a spectacular fireball.

Phew! Got away with it agan!

So Meleagertoo, your basicly suggesting that the helicopter sh** itself

OK OK I give in..........

I think you will find that the 'puff of smoke' is talcum powder used in packing the floats, just blew away when the floats were 'popped'

This has been discussed already, the smoke clearly comes from the exhaust

"I think you will find that...." sounds very patronising. However, that said.....

I think you'll find, if you look more carefully at the video, and take into account all the wise information from others who apparently understand the issue better than you, that it was from the engine / exhaust, not talcum powder. I am unaware of any engines that run on talcum powder.

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

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.

Rotorbee - thanks for your concern :ok:

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.

Could be talcum powder out of the exhaust.

All explained here:


Fly Safe, Always :ok:

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.

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

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"

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?!

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.

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

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.

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.

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

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.

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.

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.

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

that did make me chuckle:):ok:

My point all along…