EC120 Crash At Swansea Airport

[Mikeb]

An EC120 rolled over during hover taxi/landing at Swansea airport. No major injuries.

More info : BBC News (http://news.bbc.co.uk/1/hi/wales/3251349.stm)

[Thomas coupling]

Try a twin Squirrell :oh:

[Autorotate]

TC - Do you mean it was an AS355 that rolled over, or that you should try and roll over an AS355 because it rolls better :confused:

:E

[John Bicker]

EC 120 in the Beeb picture though!

[Autorotate]

Looked at the pics on the news website and definately EC120 on its side.

:E

[Thomas coupling]

I swear when I checked Mikeb's link the picture showed a squirrell. Coupled with the fact that someone just rang me and told me that a twin squirrell had just 'stoofed' in S wales.

I look again, now at the link, and the bloody picture has been changed...honest, guv!

[sycamore]

"Bit late on the collective,Hoskins"

[Mikeb]

It was definitely an EC120 Reg EI-IZO. It’s registered to Cloud 9
Helicopters ltd, Co Carlow Ireland.

Rumour has it that he clipped the apron as he was hovering to park after a rotors running re-fuel…. Apparently there are a few extra holes in the hangar and some cars in the car park were hit with flying debris. Two Cessna training aircraft were also hit with debris.

[Hoverman]

I know old TC gets off his trolley sometimes but I can't let people think he's finally lost his marbles especially now he's a TV star. ;)The BBC had a photo of a twin Squirrel and changed it.

[Thomas coupling]

Phew thanx HM. Don't know if I like the sound of 'old' though:)

[JoBurg]

No surprise there then.
That contact of yours let you down again TC ?
You should always check your info. before gobbing off.
Still easy mistake to make, one crashed Eurocopter disintegrates very much like another.
Lucky it wasn't a 135 or the casualties might have been higher.

[Matelot B'stard]

2 quick points.. I was at Swansea on Saturday, don't know how the crash occurred, but the aircraft appears to have covered quite a reasonable distance on its side, judging by the witness marks on the tarmac, and secondly.. I noticed Griff Rhys Jones having a flying lesson down there.. somebody be sure to tell him thats not how to land a helo, not even for comedy factor:p

[MightyGem]

That was hardly called for Joburg.

[Dynamic Component]

Let's guess what JoBurg flys:rolleyes:
Does it start with a B and hang in a church tower:hmm:
Have to agree with MightyGem:ouch:

[Thomas coupling]

Dynamic: It's even funnier than that. [Rhymes with Buster!].
Secondly, he's not even a pilot:confused:

[The Nr Fairy]

I was lucky to get a tour of the AAIB hangars today, as part of the SHAG day held in Farnborough by the CAA.

The EC120 in question is there, the cabin area is substantially intact, by which I mean it was on its skids, a few broken windows, dangling panels and missing tailboom, but no apparent damage to the seats or seat structure.

Some mention was made of a known pitch authority/cyclic margin issue at forward CG with a tailwind, and apparently there's a mod to add a weight in the tailboom. Anyone more experienced on EC120s confirm the veracity of the comments ?

As a result of seeing the interior, I was minded to ask if anyone knows what crashworthiness features are built into the B206 ?

[t'aint natural]

I was there too, Fairy... perhaps we met. There ought to be some special sub-Masonic greeting by which ppruners can recognise each other.
Most sobering, I found, was the molten wreckage of Steve Hislop's R44; CFIT, apparently.

[James Roc]

Spoke with the usual pilot of that craft today, he wasn't piloting at the time but his information as backed up by investigators and insurance is the unfortunate occurance of a Fenestron tail rotor stall!

[The Nr Fairy]

James:

Is this the mythical "Fenestron stall" which in any other type is labelled LTE, and for which the prevention and cure is thinking ahead ?

I'm not trying to cast stones - it's just a) we had a discussion about this some while ago and it seems LTE/FS is avoidable, b) cos it was mentioned on Tuesday as being included soon in the PPL(H) syllabus (and, one hopes, the CPL syllabus) and c) I write from a position of inexperience in these matters.

[155 Man]

I see the old chestnut of Fenestron stall raising its ugly head again. I thought this had been thrashed out long ago. Extensive trials by Eurocopter and independently by Boscombe Down have shown that it is possible to regain control after so-called Fenestron stall. Nr Fairy is right to say that this phenomenon is now more accurately referred to as Loss of Tail Rotor Authority. The trials showed that even at extremely high rates of rotation it was possible to regain control by applying full opposite pedal and keeping it applied. The rate of rotation always (even if it sometimes took a while) reduced and eventually stopped. And these trials were conducted on the Gazelle with the older, less efficient feneston. The new generation fenestrons on newer Eurocopter products (EC 120, EC 130, EC 135, EC 155) all take advantage of developments to improve both the efficiency and the noise signature.
Unfortunately, I think that if this accident was caused by loss of tail rotor authority, then it was almost certainly avoidable.

PS I think the Boscombe Down report may be available to the public. Anyone know of any sources?

[Thomas coupling]

Lets get serious here. Can anyone honestly believe that there is a company out there producing a helicopter with a known aerodynamical problem, after all the hassle from the last batch of incidences???

Is there an AAIB report imminent on this one (if no-one is hurt)?

If so, let's see what that comes up with, but I very much doubt whether that 'old chestnut' will be the cause.

[headsethair]

Nr : "b) cos it was mentioned on Tuesday as being included soon in the PPL(H) syllabus (and, one hopes, the CPL syllabus)"

I think what the CAA said at the SHSS was that LTE has always been in the syllabus, but they are about to re-emphasise it. They pointed us all to AIC 70.00 and LASORS SS17.

LTE is about to be mentioned in the report about the 206 filming accident at Hadrian's Wall, May 30th. Having to go downwind to get the shot is no excuse.

Robinson do a specific session on LTE in their safety course - the military films are comedic, but the explanations are good.

As the CAA said to us, LTE is hardly mentioned in UK training books - but if you get the US books there's plenty on it.

[The Nr Fairy]

A quick search came up with this UK accident report (http://www.dft.gov.uk/stellent/groups/dft_avsafety/documents/page/dft_avsafety_500862.hcsp) which refers to the Boscombe Down report.

Someone I know who has lots of time on Gazelles says that in the military, the non-SAS aircraft never exhibited this phenomenon - anyone know different ?

TC:

The AAIB report may well be out in some months, but seeing as the accident happened on the 7th October, I think you're showing your optimistic side.

[Helipolarbear]

As the CAA said to us, LTE is hardly mentioned in UK training books - but if you get the US books there's plenty on it.

That is because of the relevent LTE experience which became a major safety discussion for OH-58 helicopter pilots particularly, and US military heli pilots in general back in the late 70's and early 80's. Fenestron Stall amounts to the same basic aerodynamic anti- torque profile.
Concerning this particular case, I doubt that an unresolved aerodynamic factor was the catalyst or main contributory cause to the destruction of the helicopter. What speaks volumes is the crash survivability design. Amazing that ther were no serious injuries or loss of life! ;)

[Woss goin on..?]

Yes, EC120 has a forward CG issue....you cannot be in CG limits if loaded up and there is a mod around to correct this. Weight under the battery initially then weight in the end of the tail.

However, is LTE any different from any other aerodynamic problem that we learn about and deal with ie Vortex/Settling with Power, Ret Blade stall etc etc.

Sounds like 'LTE/Fenestron stall' = a cop out excuse for a handling error.

[Letsby Avenue]

Nr – The non SAS Ac are used extensively by the AAC and I have to admit we have crashed a fair few through tail rotor handling errors - the corrective actions for which, have been accurately described above. In the early days there were a few egotistical types who tried to baffle the rest of us with their wacky theories on ‘Fenestron stall’, I still remember standing in the hangar with about 20 other people while a certain prat waffled on about this and that and when he had finished, people started clapping! I couldn’t help thinking at the time; “This blokes talking b*ll*cks”. I got nice warm feeling a few weeks later when Boscombe Down stated that the so-called phenomena categorically did not exist.

[Flying Lawyer]

This is an excerpt from the AAIB Bulletin that Nr Fairy mentioned. Gazelle yaw characteristics

In the majority of civil and military cases, loss of yaw control occurred in the hover or at low forward speed in light winds from the right. A few occurred in stronger winds or with wind from the left.
Both inexperienced and highly experienced pilots were involved in the military accidents and loss of control of pitch and roll during the subsequent high rates of rotation was a commonfeature. An 'optimised fenestron' was fitted to military Gazelles in the early 1980s as part of a weight upgrade programme.
The optimised fenestron had revised duct and hub fairings but did not appear to improve the incidence of sudden loss of yaw control.

The sudden loss of yaw control was attributed to 'fenestron stall'and, in response to concern, the Ministry of Defence (MOD) sponsoreda trial by the manufacturer, Eurocopter France, to investigate the phenomenum.

The trial took place in 1992/93 and demonstrated that, in conditions of low natural wind, a relatively small left pedal input of 5% (of total pedal travel) from the hover position can result in a yaw rate of 150°/sec being achieved in 10seconds.
It also showed that high yaw rates to the left (165°/sec)can be rapidly arrested by application of full right pedal without any tendency for aerodynamic stall of the fenestron.
The MOD advice included a statement that the extremely rapid build up of yaw rate in these circumstances was exacerbated if the SASwas not engaged.

The MOD trial did not establish why a small pedal input can result in the rapid build up of very high yaw rates. However, an earlier study, in 1991, by Westland Helicopters Limited had suggested that the trigger mechanism might involve a coupling of fenestron rotor induced swirl with the circulation contained in the main rotor tip vortices which may become aligned with the fenestron in certain flight conditions.
The study also suggested that considerationshould be given to changing the direction of rotation of the fenestron to become top-blade-aft which would probably solve the interactional aerodynamic problem.
Subsequent fenestron-equipped helicopters such as the SA365 Dauphin, EC135 and EC120 have top-blade-aft fenestron rotation; they are not known to suffer from sudden lossof yaw control.