Helicopter crashes into Clutha pub, Glasgow

[welshbairn]

Why is it whenever a chopper ditches that we / the media automatically assume that a mechanical / electrical fault is to blame yet if there's a car accident then 'careless driving' jumps to mind first?

There was probably a better way of wording that but it's a genuine question, hopefully not making me sound like I'm automatically blaming the pilot or whatever.

Is it just the case that (say) 90% of chopper accidents are down to mechanical failures whereas most car accidents are down to speeding / drink driver rather than a wheel falling off?

It might be because most mechanical faults in a car occur at zero altitude.

[Hedgecutter]

Very fair and obvious (in retrospect) points, cheers. In my defence, my mind's mush after a whoor of a day.

[Sookma Broonstar]

It might be because most mechanical faults in a car occur at zero altitude.

Why, no.

Very few roads are at zero altitude.

[welshbairn]

I know of an Italian aircraft that crashed due to a rotor brake fault but I don't know if the rotors actually stopped on that occasion and I guess that would have been instantly spotted and reported by the Air Crash Investigators had it occurred on this incident.

I would also surmise that to much Collective (basically 'pulling up' to make the aircraft climb) when there was no power to the rotor head could cause it to stop rotating ! That would need an initial fault or condition for him to have been doing that and we do have reports of the engine spluttering.

I imagine there are other circumstances possible.

If (in ideal circumstances), power is lost to the rotor head and the pilot manages autorotation, what are the chances of a safe landing from 1000 feet say?

[sons superhero]

It was my understanding that although possible to strike the ground with the rotor head first in powered flight, it would be impossible to make the copter tumble from the sky in the reported fashion with or without power to the rotors. Happy if someone can explain this.

[ajwffc]

That's a strange one too. Why would this helicopter, based in Glasgow, and generally operating in the Glasgow area have flown to Dalkeith?

Any of the old police forces can call on the helicopter to aid them now it is one large force.

[Ned Nederlander]

If (in ideal circumstances), power is lost to the rotor head and the pilot manages autorotation, what are the chances of a safe landing from 1000 feet say?

This is where you need Jock 'cause I'm not a pilot - you do need some forward momentum and height to autorotate IIRC and both are interlinked - less height requires more speed !

[Ned Nederlander]

It was my understanding that although possible to strike the ground with the rotor head first in powered flight, it would be impossible to make the copter tumble from the sky in the reported fashion with or without power to the rotors. Happy if someone can explain this.

I have already stated that I find it hard to come up with a combination that would have had the aircraft tumbling as reported and today's report is worded in a way that make me think it wasn't tumbling at all :

"The helicopter did, however, remain approximately upright."

?

[BossHogg]

If only they had time to eject.

[jock001]

Let me Google That For You

AS I said, the only people reporting anything about nose over tail are from the US and they are reporting it was said by a man I provided footage of describing it as 'turning in a strange position'.

You still seem utterly certain the aircraft went end over end.

[ICTJohnboy]

This is where you need Jock 'cause I'm not a pilot - you do need some forward momentum and height to autorotate IIRC and both are interlinked - less height requires more speed !

Is forward momentum essential to make the rotor rotate?

I was always under the impression that even if the aircraft is descending vertically, the main rotor will rotate provided it is free to do so, which will then obviously seriously slow down the rate of descent, hopefully enabling a soft landing.

[jock001]

Until someone who knows responds, I'd be amazed if nothing else could cause it, faulty bearings for instance? Electronics?

P.S. The posters on the pilots' forum I linked above keep going on about the fuel, but I would have thought if it cut off the momentum of the blades would allow autorotating.

The initial report says there was still fuel in the aircraft.

[Ned Nederlander]

You still seem utterly certain the aircraft went end over end.

I have already stated that I find it hard to come up with a combination that would have had the aircraft tumbling as reported and today's report is worded in a way that make me think it wasn't tumbling at all

[welshbairn]

Is forward momentum essential to make the rotor rotate?

I was always under the impression that even if the aircraft is descending vertically, the main rotor will rotate provided it is free to do so, which will then obviously seriously slow down the rate of descent, hopefully enabling a soft landing.

I think he means that more horizontal speed when power is lost would provide more lift to autorotation, wind speed effectively. Just dropping from a hovering position would give less.

[jock001]

Why is it whenever a chopper ditches that we / the media automatically assume that a mechanical / electrical fault is to blame yet if there's a car accident then 'careless driving' jumps to mind first?

There was probably a better way of wording that but it's a genuine question, hopefully not making me sound like I'm automatically blaming the pilot or whatever.

Is it just the case that (say) 90% of chopper accidents are down to mechanical failures whereas most car accidents are down to speeding / drink driver rather than a wheel falling off?

I think people being far more familiar with cars has something to do with it although I'd describe it as people being more likely to pass judgement on drivers wheras with pilots they are more likely to decide to wait for the initial report.

[welshbairn]

The initial report says there was still fuel in the aircraft.

Doesn't prove it got to the engines.

[jock001]

This is where you need Jock 'cause I'm not a pilot - you do need some forward momentum and height to autorotate IIRC and both are interlinked - less height requires more speed !

Is forward momentum essential to make the rotor rotate?

I was always under the impression that even if the aircraft is descending vertically, the main rotor will rotate provided it is free to do so, which will then obviously seriously slow down the rate of descent, hopefully enabling a soft landing.

I never said I was a pilot, just that I'd flown.

As I understand auto rotation, you don't need forward momentum. Essentially you are just trying to maintain the momentum of the blades. If you are hovering normally the friction between the spinning shaft and the stationary body of the aircraft will try to spin the whole aircraft round in the same direction as the main rotor. To counter this most helicopters use tail rotors.

If you lose power you want to keep the blades spinning as fast and as long as possible so you maintain max lift for as long as possible. To do this you stop countering the friction and let the body of the aircraft spin round. If you don't, the friction slows down the rotor faster and you lose lift.

Edited December 9, 2013 by jock001

[jock001]

I have already stated that I find it hard to come up with a combination that would have had the aircraft tumbling as reported and today's report is worded in a way that make me think it wasn't tumbling at all :

"The helicopter did, however, remain approximately upright."

?

I hadn't read this when I posted you still seemed to be fixated on end over end.

My appologies.

[Guest The Phoenix]

I never said I was a pilot, just that I'd flown.

Impressive.

[Sergeant Wilson]

AAIB interim report:

http://www.aaib.gov.uk/cms_resources.cfm?file=/S9-2013%20G-SPAO%20v2.pdf

If only you'd posted that earlier, it would have saved all this arguing.