Another Helicopter ditches into the north sea....

[2F45T4U]

Fortunate timing and I know how you feel.

My first flight on the S76 in 1981 was a morning flight, in the afternoon a main rotor blade snapped off.

tut

ye, we didnt think much about it until see saw pictures of the wreckage coming into harbour and thinking "Christ, we were on that thing about 3 hours before "

[Alex 111s]

The lad James Costello (24) used to work for me at PSN. Smashing lad who had a bright future.

Working in the industry any incident with loss of life hits home but knowing that James died has made it much more real.
?

Me too. i was sat in PSN's offices for BP for 18 months. didn't know James that well but seeing his picture in the paper brought it home even more.

[campbell]

I've just heard the one of the guys who died was actually a survivor of the heli crash in Feb.
That is f'in unbelieveable.

[bazzam111]

http://www.eveningexpress.co.uk/Article ... 05?UserKey

very chilling, lost for words.............

[tut]

“MAYDAY, mayday – oh, f...”

Sadly that sums it up. "Maydays" are sent in threes, he did not even have time to get the third one out, within three seconds both speech and control had gone.

tut

[Scotty C]

I've just heard the one of the guys who died was actually a survivor of the heli crash in Feb.
That is f'in unbelieveable.

I think that story has been retracted?

[hendeg]

May sound cynical but the press just love this thing.

The sister of a guy that works with us has lost her partner. He said that they had to call the police last night because the press were camped outside the house and wouldn't leave. There's obviously an appetite to get as much info as possible out there but they look like they push things a bit too far sometimes.

[DavieK]

I've just heard the one of the guys who died was actually a survivor of the heli crash in Feb.
That is f'in unbelieveable.

I think that story has been retracted?

I think the guy in question was on the chopper for an earlier flight or was delayed by the last ditching not actually on it.

[tenkfeet]

Sadly the initial cause is gearbox failure , report below.

http://www.aaib.gov.uk/cms_resources/G- ... Report.pdf

[Peter]

I don't profess to know anything about Super Puma's but it would seem that the HUMS system may have given a warning but the follow up processes were not adequate enough to act upon it. Once the rotor head was detached then the outcome was inevitable.

Despite the clinical and objective way these reports are written, it's not hard to imagine what must happened in that short period of time.

Very.. Very sad.

[Northernpar]

HUMS (or variants) are now common on most aircraft rotary and fixed wing. They don't provide real time condition assessments but gather information during flight operations for retrospective analysis of equipment condition which may prompt further investigation/maintenance. Some of the techniques used are fairly state of the art employing genetic algorithms and neural networks to detect particular signatures/patterns which may be indicating a possible future failure. The down side is that it takes time to 'teach' or develop these algorithms/networks the specific signatures/patterns that they should be detecting.

Picking up a metallic particle on a gearbox/bearing magnetic plug is not uncommon but it's the follow up actions that count. Normal practice in non-aviation events of this nature would prompt a metallurgical analysis of the particle to identify it's source (easier said than done if most of the rotating metallic components are of the same metal), assessment on the size and location of the source (if the particle is big enough it may be possible to identify potential sources) and from that decide the necessary course of action; continue or strip/inspect. What the report doesn't say is that is this a one off? i.e. is this the first particle to be detected or has there been others over time? The report suggest that they are looking further into the maintenance history so I presume that this will be covered in the final report.

It does raise questions though about the maintenance and servicing of the UK fleet. I remember a number of years back offshore Norway when we were all boarded and ready to go and the captain stood us down due to a gearbox mag chip detector showing up a count. We waited until an engineer was flown out and winched down and a full inspection completed before we flew. Although both sectors are bound by the same CAA legislation it would be interesting to compare the numbers between Norway and the UK and also to compare the maintenance and servicing regimes.

[2F45T4U]

theres such a fast turn-around at Bond, considering how long it would take to analyse the HUMS data, its probable the data was being analysed from flight we were on while it was on-route to Miller.

the hole in the engine was probably the PT over speeding as the rotors/gearbox became detatched and shat its self out the side.
We were all interviewed by the police on Thursday night about it. but there was nothing out of the ordinary during the flight.

il be glad to get home on Wednesday though.

[Rich H]

We used to pull mag plugs and do extensive work on the bits that came out (You would be shocked at the mount of swarf that came out of healthy boxes all the time!) A proper knacked box would have mag plugs like Christmas trees. However the report say the main rotor head detached! The mainshaft is about 200mm in diameter IIRC and didn't get routinely checked on aircraft at all aside from visual inspection every flight.

Very random.

Rich

[David]

This brings back memories of the 1986 Chinook gearbox failure. During my flying days, I spent a time at Farnborourgh and was shown the ring gear that failed. It seems unlikely in a gearbox, but the North Sea environment caused corrosion and pitting that resulted in a fatigue crack and failure. IMHO this latest accident was probably very sudden and possibly of the same nature.

[tut]

Verian should have been on that Chinook as Flight Attendant, but her friend asked her to swap flights.

All helicopters have an engine and gearbox chip warning, magnetic plug sensors in the drain that short out with metal particles and give a warning light and audio warning in the cockpit. Standard procedure is to land as soon as possible, Platform or mainland, whichever is closer. Most warnings are spurious, but as Rich says, if the filings are above a certain density, the aircraft is grounded for further investigation.

As I posted earlier, the only cause that I could see was that the rotor blades stopped turning, as opposed to detaching, which would have been even more catastrophic. As a pilot I always thought that regardless of engine failures, main gearbox failures, or even transmission failures, the main rotors would continue turning as long as they were still attached to the rotor head.

Looks like I was wrong.

tut