I was under the impression that UK police helicopter pilots use NVG's. Unless I have missed something, I gather that this is not the case?

Re__
 

Bladecrack and Wetbulb,
I can't agree with you both more!

Too many barrack room lawyers and uninformed people here.
Not to mention the Flight Sim commanders.
Such a very sad situation and no valid opinion should be cast until the Aib have done their stuff.
I rest my case!

You folks are aware of a second thread reserved for Condolences and similar messages of sympathy?

This thread is for the discussion about the possible causes of the accident and other related issues....and like it or not...just as this is a topic of discussion in all sorts of venues around Glasgow and the rest of the UK it will be discussed here at Rotorheads.

This is no different than any other Fatal Accident in that regard.

Sad as the loss of life is.....it is part of flying helicopters for a living.

You don't like what you read here....don't attend the Thread and stick to the Condolences Thread.

This is just and extension of everyday life in the Helicopter Industry....and topics of the day are going to be discussed.

I know some here have poo-pooed the idea that the crew fatalities were caused by a secondary drop. Please tell me where my logic is wrong:

Rotor blades appear reasonably intact - strongly suggesting they were stationary or at least only moving slowly when the heli went through the roof.

Multiple bar patrons report a two-stage collapse of the ceiling, with some duration of pause between the initial impact and the total collapse.

Members here have stated that if "it dropped like a rock" with the blades not turning, then the multi-ton craft would have smashed through the fairly weak roof on initial impact.

Also stated by members - an auto-rotation or semi-controlled landing "soft" enough not to immediately collapse the roof probably would not have resulted in fatalities.

So - is it not possible that the pilot and police officers "landed," halted the blades and possibly removed their seatbelts/harnesses in preparation to get out of the craft, and that's when the roof gave way?

A previous poster on this thread, a builder by trade, pointed out that buildings when impacted tend to collapse in distinct stages, so an interval of time may take place between the first impact and when the materiels used in the construction have stretched or separated. A secondary collapse of the roof may then take place, as those in the bar reported.

Also, time experienced by observers may not feel the same as the actual minutes elapsed. I know that in case of a launch failure, time seems to slow down, you can do quite a lot in 30 seconds if you know what to do.

A tragic accident indeed to which I offer no comment at all on until seeing an accident report. Seems almost every possible reason as to why the crash happened has been covered here by the experts, entertaining reading it sure is and an absolute smorgasbord of reasons for the media to repeat. Even after 34 years of flying I wouldn't even begin to entertain a reason, but I guess that's just me.

I thought that I would have a look at this thread to see if there was any intelligent discussion over this tragic accident. I might as well have read the Sun newspaper. Intentional landing on a pub roof, LHIRF, vortex ring, drug-crazed snipers, lasers? It will be alien abductions next.

Very sad news and made worse by the BBC rolling out that lump called Chris Yates the man whom has the knowledge of a dried out prune. I wince every time that prat opens his mouth, please if there is nothing new to say dont say anything....

Re damaged fenestron, could it not have hit the roof first?

SASless, re engines running, that's what the freewheel units are for.

Just heard one of the pub patrons - a young Northern Irish chap - being interviewed over on Radio Ulster. He was one of the first out of the building and, not knowing what had happened, he asked a bystander what had happened.

The bystander apparently told him that he had witnessed the helicopter autorotating onto the roof, and qualified this by saying he was ex-military and familiar with the technique.

Time out
 

Time to lay down a few points for those unused to the Rotorheads forum.

This thread has obviously attracted a lot of attention, and whilst Rotorheads is a welcoming community it is becoming obvious that there are a lot of posters here who normally inhabit R & N and have brought wild speculation combined with a woeful lack of basic knowledge of helicopters and their operation.

A number of helicopter pilots have offered advice: please accept it and end the red-top speculation. There are well over 300 responses so far (including those that have had to be moderated) in only two days, and we have now deteriorated into endless debate between non pilots which is trying the patience of many Rotorheads.

Also, there is a separate thread for condolences: any posts here that include condolences will be moderated or deleted.

Apologies for having to preach to the converted, but our guests would benefit from making less inflammatory posts and reading the contributions from our helicopter pilots.

Well said SP, although personally I was looking forward to the alien abduction theories!

Unless I have missed it, I don't think that it has been mentioned that to complete a successful autorotative landing following a tail rotor (fenestron) drive failure, it is necessary to shut down the engines in flight. There are other techniques if the emergency starts with enough height or speed to maintain or recover directional control.

This to me has indicators of a marginally successful recovery from TRD failure at low speed and low altitude, followed by catastrophic failure of the roof that they landed on.

All - does anyone have a cutaway view or schematic of the EC135 transmission or similar that they can post please?
Am trying to envisage how power is passed to rotors, but still allowing transmission to freely rotate if necessary.
Read a post or two by the pilots who are familiar with the machine, but still having trouble.:(
Have searched Google without much luck.
Am just curious.

Tartare,
Helicopter = Bicycle
Back Wheel = Rotors
Pedals & Rider = Engine

Turn pedals with feet, back wheel turns, bicycle moves.
Stop pedalling, bicycle stops.
Going down hill, don't pedal, bicycle keeps going = autorotation.
About as simple as I can make it

In the case of the 135, the shape of the tail fin, essentially a wing mounted vertically, achieves most of the anti torque force required but only when above 70kts ish. As Sven has already alluded, if you lose tail rotor drive, the only way to have a successful landing after autorotation is to shut the engines down to lose the torque.

VERY INTERESTING
 

I am ex forces.Air Traffic and low grade pilot but always interested in causes of accidents,( hope to learn by the mistakes of others). As the witness statements all differ it has been good to read all your comments. both common sense and idiot material , and the views of very experiences rotor and fixed wing pilots.

I lament the useless ill informed and utterly wrong comments by reporters/ journalists and the ex forces tw@ who spouted off to Sky Tv the night of the crash .

My own view is unimportant but I am glad idiots do post on here at times because that usually brings out intelligent rebuff that is based on operational knowledge and engineering knowledge that gives credibility to some of the more enlightened views expressed. It will be interesting to read the AAIB report on this event in the future to see what exactly failed .

This is a very sad happening for all concerned, but it seems that many ground witnesses stated the Rotors were not turning.....could this be that the Strobe lights could/would cause that stationary effect to the rotor to those people looking up on a very dark night, similar to that effect which is often seen when a propellor is seen through a video.?

From the information so far, we are still open to much speculation.

As I see it there are still several possible reasons for this crash. These could include the following.

1. Vortex ring. Probably from losing control or getting disoriented in a high hover.

2. Catastrophic mechanical failure. Possibly a gearbox / transmission failure requiring an immediate landing. There may have been time to choose a landing area. This one might have been the best choice under the circumstances.

3. Tail rotor failure. Rarely ends well.

4. Tail rotor control failure. See above.

5. Double engine failure. This would require entering autorotation. The success of this would depend on many things eg. height and speed at entry and how good the pilot is. I suggest it would be a rare occurrence.

6. Some lesser emergency requiring an immediate landing. I'm not familiar with the type but this may include chip detector lights, low oil pressures, overheats etc. Maybe the landing was relatively under control but the roof just couldn't take the weight. You would have to ask 'why there?'

7. Pilot incapacitation. Heart attack, blinded by laser, shot etc.

8. Missile strike of some sort.

The list goes on.

There are probably other possible reasons. Whatever the reason, you have to ask why the helicopter was there. Was there a Police operation in progress? Was it hovering or in forward flight? How necessary was it for the machine to be where it was?

Ok, fair enough forty, I'll leave you experts to it. Experts that announce to the world that if you lose tail rotor drive (EC135) the only way to have a successful engines off landing after autorotation is to switch the engines off!

After all, what would I know!

Looking at the hull being lifted - it is remarkably intact. Looks like it could have impacted nose first.