more on helicopter crash.

[Dave Liquorice]

But he'd asked permission to enter the Glasgow controlled area 4 minutes before the crash, the last communications from the craft.

[Nightjar]

Nothing in the Rules of The Air to prevent it. The relevant part is Rule

5, low flying, and in particular: 5.(3)(a) An aircraft shall not be flown below such height as would enable it to make an emergency landing without causing danger to persons or property on the surface in the event of a power unit failure.

Which is covered by flying down the river.

5.(3)(d) An aircraft flying over a congested area of a city, town or settlement shall not fly below such height as would permit the aircraft to land clear of the congested area in the event of a power unit failure.

That is a bit more difficult over a large city with a single engine helicopter, given their glide angle, and is why most operators use twins over cities.

Most of the rest of Rule 5 does not apply to a helicopter being flown on a Police Operator's Licence.

Colin Bignell

[Nightjar]

That is an order of priorities, not a sequence of events. It can be perfectly possible to do all three at the same time.

The lack of any radio contact suggests everything happened very quickly.

Colin Bignell

[Andy Burns]

Yes I understand that, but could well imagine that falling out of the sky doesn't let you get much past the first item, perhaps as far as which patch of ground you'd prefer to hit.

[Terry Fields]

Is there any chance that the two engine fuel-tanks did in fact get drained in use, resulting in the helicopter having no lift, and some of the remaining 95 litres of fuel drained into them from the main tank in the two days or so post-crash?

Comments made on pprune suggests there is a complex system of warning lights, pump switches, and operational requirements (hover, flight < or > 80kt)(gravity related fuel transfer?) in place regarding keeping the two engine supply tanks full.

[Nightjar]

The design of the supply tanks is such that, even if the fuel feed to both is cut off, one engine will run out of fuel a few minutes before the other. Whatever happened to this helicopter was sudden and unexpected, which makes me think that, pending any further information, compressor stall due to an external disturbance is the highest probability cause.

Colin Bignell

[GB]

A flat roof seems a reasonable choice. The pilot could have had no idea from way up high that it was a pub. A roof would be a lot softer than a patch of concrete. Perhaps the pilot did aim for it?

[Adrian]

Surely the illumination of the signs would have been visible?

[fred]

Is this particular kind of speculation really any help at all?

To answer your points:

The location concerned is an exceptionally well known landmark junction in Glasgow, the bar is equally well known and it is inconceivable that anyone living and working around the city would not know of its existence and recognise it immediately from its distinctive surroundings, even at night.

To suggest that a professional pilot would choose to crash land onto a building to avoid personal injury at the risk to anyone that might have been inside, and in particular into a crowded bar (10:30pm) is, I think, more than a little insulting.

Knowing the area well, it is clear that whatever happened did so in a very short space of time, there are many wide open spaces, including parkland, within half a mile of the crash site so to be forced to land anywhere in that particular location must have been as a result of a true emergency with little or no warning.

The first thing I thought of when I heard of the location was the possibility of a pilot attempting an emergency landing on the adjacent junction as a place of last resort, it is where five, 3 & 4 lane roads meet and its area is not far of that of the heliport where the helicopter operated from.

There is also significant waste ground on the riverside bounded only by railings (not lamp posts) on the river side and the 4 lane Victoria bridge immediately beside it although that does have quite a few intrusive lamp standards.

General location here:

Heliport here (same scale):

Can we perhaps leave speculation about the pilot out of this one?

[Richard]

Hmmm....

[The Natural Philosopher]

+1

total power loss on both engines followed by a panicky response in which the pilot had only a couple of seconds to do anything, and chose 'full collective' and stalled the rotor as well.

That makes more sense than anything else.

[unknown]

As an "experienced pilot" and long time instructor I can assure you that it is quite easy to make a switch pigs whilst distracted, which is partly why most Commercial Ops have 2 drivers.

[Dave Liquorice]

The river softer still, and very little chance of taking out anybody on the ground (river).

[Adrian]

I dunno about that. Can't remember if it was pprune or the AAIB interim, but there was an estimated impact of about 30G. At that rate, there's going to be bollock all difference between water and concrete - but a lot less chance of your body being quickly recovered.

[tony sayer]

Its the same over on uk.railway where no end of pundits will give their reasons behind any event before the RAIB have even got to site;!...

Plus the most important the train and/or loco number.....

[docholliday93]

From what I read about witness statements I'd suggest that you could safely remove the first three words of that sentence...

[The Other Mike]

Full collective up in anything remotely like that situation makes no sense to anyone who knows that while the lever might look a bit like a handbrake it clearly isn't.

Even after an hour or so of basic training the handling of controls and the importance of rotor rpm is already deeply embedded in the mindset of a student pilot. That someone with thousands of hours flight time would purposely act in the exact opposite manner is, IMHO, not credible.

Not being able to lower the collective fully and regain or retain an appropriate rotor rpm might be an issue, but then again lots of other things could be too.

[The Natural Philosopher]

30G should be survivable in a decent crash structure, strapped in.

[Adrian]

There's three stops involved in any big crash...

Your vehicle stops. That's fairly easy to mitigate - design it to crumple and absorb the energy. Your body stops. That's fairly easy to mitigate - restrict the movement relative to the vehicle. Your internal organs stop. That's the really, really difficult one to mitigate.

[Bob Eager]

Hmmmm.....

- angle grinder - no help

- WD40 - no help

- expanding foam - well....