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-   -   French Lighthouse Ops incident, 6 July 2022 (https://www.pprune.org/rotorheads/647692-french-lighthouse-ops-incident-6-july-2022-a.html)

meleagertoo 9th Jul 2022 12:42

UK (and others?) military slang, originally rendered as "half crown, thruppenny-bit, dustbin-lid" as I heard it.

Heinrich Dubel 9th Jul 2022 13:20


Originally Posted by meleagertoo (Post 11258875)
UK (and others?) military slang, originally rendered as "half crown, thruppenny-bit, dustbin-lid" as I heard it.

Generally signifying a messed-up situation, I assume.
Thanks for replying.

[email protected] 9th Jul 2022 14:07

Heinrich - it refers to the size of your sphincter changing during a high- situation (half-crown is bigger than threepeny bit and dustbin lid speaks for itself) ie normal, pucker, full dilation!:)

As for the incident, the way the fuselage rotates is exactly what you would expect from a sling load still attached when you thought it was released and started to move away.

The cloud of dust is certainly the floats being fired and you can see the starboard skids ones inflated - the bright orange.

Lucky guys.

Heinrich Dubel 9th Jul 2022 15:37


Originally Posted by [email protected] (Post 11258916)
Heinrich - it refers to the size of your sphincter changing during a high- situation (half-crown is bigger than threepeny bit and dustbin lid speaks for itself) ie normal, pucker, full dilation!:)

Got it. It’s an eqivalent to the US military „pucker factor“, but with reference to the actual (size difference) factor.

Thanks

albatross 9th Jul 2022 20:03

I respectfully disagree about the “ dust cloud “ being from float deployment. It would take a heck off a lot of baby powder to create that effect. Far, far more than the amount I have seen used to repack floats. Also it does appear to emanate from the engine exhaust area.
A truly close call. Glad he made it. A little lower and he would have face-planted onto the rocks or into the water or combination of the two. Time to purchase a lotto ticket..his lucky day.


Originally Posted by [email protected] (Post 11258916)
Heinrich - it refers to the size of your sphincter changing during a high- situation (half-crown is bigger than threepeny bit and dustbin lid speaks for itself) ie normal, pucker, full dilation!:)

As for the incident, the way the fuselage rotates is exactly what you would expect from a sling load still attached when you thought it was released and started to move away.

The cloud of dust is certainly the floats being fired and you can see the starboard skids ones inflated - the bright orange.

Lucky guys.


[email protected] 9th Jul 2022 21:12

And they do generally pack them with a lot of baby powder.

Have you ever seen an exhaust spit out a plume like that without being on fire?

Look at the Stbd skid towards the end - it is bright orange indicating that the flotation bag has started to inflate - not fully in this case so perhaps the nitrogen escaped enhancing the 'dust cloud'.

A681001 9th Jul 2022 21:35

Was Lifting frames from lighthouse lantern
https://aviation-safety.net/wikibase/280069

Hughes500 9th Jul 2022 21:48

White smoke from the engine without a doubt. looks like a longline caught on the lighthouse, only way i can think of such a rapid pitch down ! Good save though. I bet there is one scrap 350 now

albatross 9th Jul 2022 22:20

Yes I have….oil blew out of the Turbine Labyrinth seal on a 250 C20B causing a massive smoke cloud out the exhaust that would have the turned the Snowbirds green with jealousy. It. was like landing in fog. Oil pressure was at the bottom of the green when I landed, I didn’t do the cool down before shutting down. When I looked out the back there was a smoke trail for a mile behind me. Luckily I was on approach to the pad when it happened. The engineer saw it all happen.

Originally Posted by [email protected] (Post 11259042)
And they do generally pack them with a lot of baby powder.

Have you ever seen an exhaust spit out a plume like that without being on fire?

Look at the Stbd skid towards the end - it is bright orange indicating that the flotation bag has started to inflate - not fully in this case so perhaps the nitrogen escaped enhancing the 'dust cloud'.


uxb99 9th Jul 2022 23:18

I love all the debate about the smoke cloud. Perhaps the smoke is coming out of the engine because the pilot is redlining that bitch in an attempt not to splat himself on the rocks below?
Reminds me of one North Weald fighter meet when a Harvard gave out a large gout of white smoke as it passed the crowd line the commentator quipped "There goes a cylinder and a couple of valves".

[email protected] 10th Jul 2022 06:07

A turbine seal letting go would have caused the smoke to keep on going, even after he had avoided the ground.

I've seen engines overtorqued and overtemped but never seen a temporary smoke cloud like that from grabbing a handful of collective.

You know the flotation bags are packed in powder and inflated with nitrogen and you can clearly see the flotation bags have inflated during the dive towards the water.

Seems pretty clear cut to me - if its not the powder it is the excess nitrogen (cold gas under pressure) expanding and cooling the air.

It's a single-engined helicopter, if he has buggered the engine so badly it starts to smoke, how does he recover to the hover with no smoke evident?

megan 10th Jul 2022 06:36

Did see smoke come out the exhaust of the type when a chap gave a rather enthusiastic display at an airshow, occurred during the pitch over at the top of a very steep climb following a low level high speed flyby ie low "g".

Cornish Jack 10th Jul 2022 09:58

Apologies, Heinrich - the explanations given above are correct ... wrinkly reversion to non-metric currency !!
Re. the smoke from the exhaust, early Lynx at Boscombe doing pitch over for speed runs used to exhibit mini versions, and one of our Whirlwinds, coming in from Valley to TH with an uncoupled (accidental) throttle linkage produced a similar, but more flame containing example ! :eek:

Nubian 10th Jul 2022 10:56


Originally Posted by A681001 (Post 11259050)
Was Lifting frames from lighthouse lantern
https://aviation-safety.net/wikibase/280069

Well, I take it that they where lifting those frames down to the platform on the ''pilot'' side of the tower from the lantern. WHY would a pilot with any sense do this in tailwind?? and with the structure on the opposite side of the helicopter... Looks seriously poorly planned and worse executed. If you'd do this exercise in the opposite direction, I bet there would not be a thread.

As for the smoke. Full screen the video, playback and stop between 0:10-0:12 and you see the smoke is coming from the top halv of the helicopter. There is no parts of the floats up in that area, nitrogen lines or baby powder. So clean cut?! Nope. I bet that during this display, the aircraft had more than one over limit, and no, even a single engine that is being seriously over torqued and over sped, don't just quit and fall out of the sky.
I would put my money on that the white smoke is engine oil which due to the unnatural abrupt motion and attitude has been pushed into the exhaust via the vent-pipe from the oil reservoir, and that creates a lot of white smoke, and it would be temporary.
It looks like this was an uncontrolled cyclic input for some reason, or more likely a gust of wind from below and behind while attached to the load...

Very lucky recovery and escape by the pilot, very lucky...!

[email protected] 10th Jul 2022 15:35

There is no room for the nitrogen bottles on the skids so they have to be somewhere in the fuselage with the lines running down the skids to the bags.

It is definitely not an uncontrolled cyclic input - it is a reaction to being pulled by a load which is still attached.

I've flown pushovers in the 350 and it definitely does not do that white smoke thing.

212man 10th Jul 2022 15:39


I would put my money on that the white smoke is engine oil which due to the unnatural abrupt motion and attitude has been pushed into the exhaust via the vent-pipe from the oil reservoir, and that creates a lot of white smoke, and it would be temporary.
That's where my money is too and I'm not sure what people are suggesting will happen if you pull more than the rated power - i.e. what the smoke will actually be caused by? Engine certification is pretty stringent, and 3 seconds pulling a bit more than the RFM allows is not going to result in any external visual effects (https://www.ecfr.gov/current/title-1...pter-C/part-33).

White smoke from an exhaust is either oil or unburned fuel, and I very much doubt the latter.

[email protected] 10th Jul 2022 17:00

This what the Aviation Safety Network says in its report

The pilot recovered the aircraft a few meters from the surface of the sea, in a maneuver that caused the release of a large cloud of smoke that was visible when the emergency floating devices are activated.
Emergency buoyancy has been triggered.

Nubian 10th Jul 2022 17:01


Originally Posted by [email protected] (Post 11259307)
There is no room for the nitrogen bottles on the skids so they have to be somewhere in the fuselage with the lines running down the skids to the bags.

It is definitely not an uncontrolled cyclic input - it is a reaction to being pulled by a load which is still attached.

I've flown pushovers in the 350 and it definitely does not do that white smoke thing.

And I know where they are located….just as a hint.

I have done a bit of rollercoasting in the 350 as well without smoke, so don’t feel bad….

The abruptness of of the manoeuvre I think is they key. I said it could look like an uncontrolled input, not necessarily that it is so. Having had the pleasure of having my electric longline release failed on me after setting down load number ### being in a good flow on short rotations with ca 1 ton of bags of gravel, and pulling collective on instinct as I could “see” the straps fall of the remote hook, I can tell you how a snagged longline feels. I did not produce any smoke, nor was the machine reaching any over limit parameters, I didn’t pop the floats, didn’t end up almost hitting the ground, but we confirmed that the shoulder harness worked as advertised, so did the belly release and we had a brake to chat with the technicians on how to proceed.

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…


[email protected] 10th Jul 2022 19:17

So explain exactly how so much oil - that is a lot of smoke - gets from the reservoir to the exhaust, it is only a breather pipe after all.

megan 11th Jul 2022 02:04


I've flown pushovers in the 350 and it definitely does not do that white smoke thing
Crab, I can assure you on this occasion it did, a Squirrel some decades ago, not great plumes as in the video though, having viewed the event I made a point of examining the exhaust and noticed the breather and assumed that may have been the source, pilot was reputed to have trashed an airframe of another type from his vigorous displays.


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