more on helicopter crash.

[harryagain]

Pilot, instruments, fuel.

[Windmill]

I've wondered from the beginning if there was *any* fuel at all in the copter. That's more common than one would hope it might be ('Gimli Glider', Air Transat, ...........).

The eventual accident report (maybe years from now) should explain, but in the meantime a lot of people will want to keep quiet for one reason or another.

The BBC did say, quite early on, that the manufacturers would not be taking any action, apparently having decided that the accident was the result of 'operational factors'. Maybe they knew something which we still don't.

If there was in fact fuel in the tanks, I would have expected someone to clearly say so at the time, just because it is an obvious possibility that there was none.

No fire, and no indication that the fire brigade were worried about the possibility of fire.

All I did hear was someone saying that the tanks were designed to be 'crash proof' (?) and that the fuel had anti-misting additives to reduce the likelihood of inflammable vapour. Which says nothing really.

Of course if the spooks were involved we might never know anything.

[Chris J Dixon]

With the rotors stationary, I'm not sure that the pilot has any further means of influencing matters.

It is reminiscent of the reports, following the rail crash at Grayrigg, like "The train driver, Iain Black from Dumbarton, whom Virgin trains boss Sir Richard Branson described as a hero after the crash...". With the emergency brake applied and the train derailed, all the driver can do is cling on, nothing further can make a difference.

Chris

[Chris Hogg]

How do they know the rotors weren't rotating? Was it just from eye witness accounts; is there some on-board indicator which tells them, or was it from the damage, or lack of it, on the rotors themselves?

Also, if the power to the rotors stops for some reason, and the helicopter goes into free fall without changing the angle of attack of the rotors, they will start to rotate in the opposite direction, which means that at some point, rate of rotation is zero. Depending on the height from which it falls, that point of zero rotation may occur just before or as it hits the ground.

[GB]

Also, surely it would be quite easy for AAIB to see whether the rotors were still turning? They would have smashed against parts of the building, and the leading edges in particular would have suffered damage.

[GB]

I remember, when the children were small, dreading the question: "What does this button do, Daddy?", because they *always* pressed it at the same time as asking!

[Nightjar]

That is why the blind flying instruments have built in redundancy. Not that it is relevant as the weather at the time was CAVOK.

Colin Bignell

[Nightjar]

It would have been from examining the damage to the rotor blades, its nature and direction of impact.

Colin Bignell

[Weatherlawyer]

Sounds to me like all you have left is the weather. There is a type of wind sheer that is a massive downdraught but I can't recall the name of the phenomenon.

That might not appear on weather reports as it is localised but the overall conditions in which it might occur are well known. What was the date of the event?

[Nightjar]

Whichever the writer prefers, although I tend towards the Old English while and among, rather than the Middle English whilst and amongst myself.

Military pilots fly what they are given to fly. The RAF lost 22 Vampire jets, with 10 fatal crashes, in a single year. The German Starfighters had a particularly unfortunate record. The Americans claimed that was due to poor maintenance, but the fact that they were a low level variant and often flew in relatively bad weather were certainly factors.

Colin Bignell

[GB]

Which translates as Ceiling and Visibility OK

[Andy Burns]

They changed the discription from "CAVOK" to "visibility greater than

10km with a few clouds at 4000 feet" as far as I can tell CAVOK implies no clouds below 5000 feet, so probably little difference in reality, just getting the facts straight.

[Nightjar]

From the AAIB report:

At 2220 hrs the weather at GIA (Glasgow airport) was CAVOK with the wind from 300° at 7 kt, temperature 5°C, dew point 2°C and the QNH was 1025 hPa.

I don't see any especially high buildings in the area that might give rise to unusual winds.

Colin Bignell

[Nightjar]

It translates to visibility >10km, no cloud below 5,000 feet, no cumulonimbus, precipitation, thunderstorms, snowstorms, dust storms, shallow fog, low drifting dust, sand or snow.

As Harry has told us he flies gliders, I assume he knows that.

Colin Bignell

[Weatherlawyer]

"The report found that the aircraft struck the building with a ?high rate of descent? but little or no forward motion. This tallies with eyewitnes s reports that it ?dropped like a stone?."

Microburst. The word escaped me earlier:

It would have rotated on engine failure unless impeccably balanced. Maybe the bangs heard were thunder of some sort or the blades clashing?

"On 29 November 2013, a police helicopter crashed into the Clutha Vaults, a pub on the north bank of the River Clyde in central Glasgow."

29 November that is a day to remember. My forecasts for a major geo-physics event went awry on that day. Something to do qwith tornadoes that never oc curred IIRC.

Yes, that's right:

se]

[Syke]

I seem to recollect that some, at least, F-104s had downward ejection seats, which wouldn't help much.

Regards

Syke

[John Williamson]

The description of visibility greater thah 10 km with a few clouds at

4000 feet was five minutes after take off, CAVOK was noted at the time of the incident, according to the AAIB report. Both at GIA, which is five miles from the crash site.

[John Williamson]

Windshear wouldn't have stopped the rotor blades. The report notes that neither the main or tail rotors were rotating at the time of impact. It doesn't even say that they were "apparently" stationary, so they are

100% certain that they were not rotating.

[tony sayer]

Interesting thread/s here from some chopper pilots...

[The Natural Philosopher]

at a guess the latter

yes...