SS - I like that one, concur completely!

Falcon - whilst I do have further opinion, I'm going to leave it at that for the moment since I've already said it, effectively.

I am NOT suggesting that a relight was attempted by the captain.

I wondered if due to the pitch change from cruise to autorotation, a small amount of fuel was picked up from the main tank by the transfer pumps, to the supply tanks, and to the engine / engines.

The high temperature in the combustion chamber MAY? Have ignited the fuel for a short time
miss leading the captain that a full relight was underway.

I have only fixed wing jet time so have no idea how you would handle such a situation.
I can be fairly certain that this has never been trained for in the simulator.

You might just be wrong there! We won't know for a little while yet.

Talkpedlar,
it would be neither fair nor accurate to say that I have "never flown this (or any other) helicopter", but in truth I am struggling to see the relevance of your question in the context of my posts.
If you had read my posts, you would not find any criticism of the pilot. My hypothesis has him being put in a virtually impossible situation by a train of events emanating from optimistic fuel readings caused by faulty fuel probes.
You sound very matter of fact about dealing with a loss of engine power, over a city centre at night, which surprises me. Notwithstanding his unquestioned skill and capability, an autorotation in such circumstances would have been a very tall order, which I happen to believe the pilot very nearly pulled off (which incidentally explains the negligible rotor speed. see post 449 and others on this thread.)
Of course I am speculating, and of course I could be wrong.
Cheers

Falcon900


My hypothesis has him being put in a virtually impossible situation by a train of events emanating from optimistic fuel readings caused by faulty fuel probes.*:D

I completely agree with you.

Robin 400, there is no continious ignition switch in the EC 135 like it was in the BO105.
The FADEC does all the work.

skadi

Fadec
 

Thanks. How well would it cope with the possible situation I have been suggesting?

Robin400,

If there were "sparks" and "bangs", as reported, then the idea of intermittent pulses of fuel making it into the engine and igniting roughly and inefficiently on still hot turbine components seems reasonable. But these "sparks" would only need to come from one stopped engine. The reported "quiet" would indicate two stopped engines? Could "sparks" also be the reflection of a strobe from the yellow upper parts of a helicopter doing something unusual?

Ingesting something could presumably do the same, causing stalls and burps.

Falcon900,

The substantial damage to the cabin in the salvage photos looks inconsistent with having just missing a gentle landing. I'm sure the impact speed will ultimately be very clear from the wreckage. Many witnesses, including very-promptly-interviewed ones, also say that they saw the aircraft "drop" from above the height of nearby multi-story buildings. There's sure to be a good radar trace for initial height (right?) and perhaps a history of the position of onboard GPS devices. I have no doubt that this issue will ultimately be resolved accurately.

I tend to agree with the skateboard view. More information is required and to be synthesized.

awblain. Thanks for your thoughts.

I was under the impresion that both engines were stopped.

I agree.

What conclusions do you feel able to draw from that?

The most likely conclusion is that the supply of Avtur to both engines ceased:eek:

What can stop two seemingly serviceable engines other than a manual shut down or fuel starvation?

You chaps really aren't using your imagination!

As I see it, failure of a NRV or the fuel transfer pipe would trap fuel in the main tank, starving the supply tanks and ultimately the engines.

The FAA fuel system requirements are:
Fuel System Independence
Each fuel system for a multiengine airplane must be arranged so that, in at least one system configuration, the failure of any one component (other than a fuel tank) does not result in the loss of power of more than one engine or require immediate action by the pilot to prevent the loss of power of more than one engine.

Eurocopter being such a huge company would have this covered, ....wouldn't they?

Wouldn't that be failures (plural) of the fuel transfer pipe, or the check valves (plural) - with neither main tank pump being able to fill the transfer pipe, and both supply tanks draining too much back into the main tank, in a nose-down attitude.

No single blockage/breakage in the transfer pipe segments between i) the aft pump, ii) the spigot for supply tank 1, iii) the spigot for supply tank-2 and iv) the forward pump should starve the supply tanks, unless only one main tank pump was submerged. From the pictures below, I can only see that working in a nose down attitude too - with the supply tanks draining back into the main tank.

At the bottom of the pages
Heli down - Page 2 - General Helicopter Forum - Vertical Reference Helicopter Forums
WWW.CRASH-AERIEN.AERO ? Glasgow : un hélicoptère s'écrase sur le toit d'un bar (as in post 1026)
seem to be variously accurate looking plans of the underfloor bladders.

TR
It has been suggested that just because the engines stop there is no reason why a successful autorotation couldn't be carried out. Please correct me if I'm wrong, loosing the engines would mean loss of rad alt and search light so judging the flare would be very difficult wouldn't it?

Cabby
 

Please refer to page 1890

Autorotative landing is a visual manoeuvre, which has little to do with radalt.

Whilst the result might not have been perfect, ambient lighting would be sufficient to have had a much better stab at this than appears to have been the case here.

Only my opinion of course.

TR,

I think your opinion is valid. After well over an hour airborne at night, the crews' eyes should have been as adapted to the dark as they can get. The scattered light from the surrounding street lamps should have been very helpful in judging the distance to the ground. The location of the street lamps, and building lights should also have given potentially good sense of visual flow as the ground neared, in the helpful context of diffuse background light.

From the wreckage photos, I suspect that the aircraft "dropped" from at least many tens, and possibly hundreds, of feet. Perhaps compare the wreckage of the Norwegian air ambulance that looks like it fell about 200 feet.

I'm not aware of any aircraft that would lose rad alt, landing lights, etc etc in the event of a double engine failure. There is a battery on board, and most ancillaries are driven from the main rotor gearbox, so whilst the engines or rotors turn the gearbox and the battery is switched on, then you should have all you need for an emergency/forced landing.

It seems the rotors/main gearbox were not turning. Images of the blade tips indicate this and the AAIB report confirms the fact. Astonishing information.

It seems the engines were not running - but perhaps could have been given the amount of fuel recovered. Coupled with the above, astonishing also.

Without a doubt the most curious of combinations.