Ed Helicopter Crashes into Glasgow Pub

[Darth Rotor]

I wrote that the pilot must have been able to at least see the fuel gauge.

Must? Why do you say that?

Yes I agree. But also, there appears to be no evidence that the pilot even attempted an autorotation.

Why do you say that? There is no DFDR. You and I have no data to support either case.

The evidence - as I understand it - is that the helicopter dropped out of the sky in a level attitude, with the blades having lost pretty much all rotational direction.

That is one way to interpret the information currently available.
So too is an attempt at an auto that was late and as such did not avoid blade stall.
Low Inertia Rotor Head.
So too an early pull. An early pull helps support the more or less upright attitude of the helicopter at impact, which was with great force. Caving in the roof isn't that easy to do.

Suggest you read a few posts from about 21 Feb to today, 25 Feb, by a chap with the handle SilsoeSid over at PPRuNe Rotorheads forum. He makes some interesting points on displays. Some other gents have some well thought out points on the fuel system and when the transfers stop and start.

Why the fuel transfer switches were not on include the hypothesis that the pilot may not have been able to read a fuel gauge.
No idea if that hypothesis has legs, or not. It's an open question.

Hang on a moment! YOU were the one who suggested that that was "how it went down" in the first place!

My best guess, and with acknowledgement that it was a guess.
No "MUST" or declarative statements like you have been doing.

Lacking the FDR and CVR like there was in the AF447 crash, there is a lot about this wreck that can never be known.
A real bugger for the AAIB to sort out.

 

[Soapy Sam]

LondonJohn's suggestion that the apparent inconsistencies can be explained by a deliberate act is correct. It can. He has never said though, that it's the only explanation.

There may be technical explanations- It seems the 10 minute warning is not clear cut. the apparently stopped rotor may have stalled or may indicate a failed autorotation. On those and others , I bow to those who know the systems.

I know Glasgow.

I don't see two Glasgow polis getting in a chopper with a pilot they thought might be suicidal.
I can very easily imagine them egging him on to ignore the fuel alarms and head straight for home, so long as they didn't seriously think there was a danger. If he looked calm and in control, they probably encouraged him to go for it.
Now that would seem very stupid- unless they were in the habit of cutting it fine on these trips and had maybe seen the alarms before.

If we are looking for behavioural / psychological explanations, I think the "Gie it laldy" mentality is as likely as a deliberate act.

 

[Darth Rotor]

The EC-135 fuel system has its problems.

That said, most operators know how to deal with the problems and the aircraft has a pretty solid operational history.

On a given night, if the indications were going a bit wrong, the pilot may (not MUST, John) have been looking at conflicting indications of fuel remaining. (And may not).

Beyond that, I'll go back to lurking over at PPRuNe Rotorheads. Some very well expressed explanations of both police flying and the EC-135 over there.

 

[LondonJohn]

The EC-135 fuel system has its problems.

That said, most operators know how to deal with the problems and the aircraft has a pretty solid operational history.

On a given night, if the indications were going a bit wrong, the pilot may (not MUST, John) have been looking at conflicting indications of fuel remaining. (And may not).

Beyond that, I'll go back to lurking over at PPRuNe Rotorheads. Some very well expressed explanations of both police flying and the EC-135 over there.

You may be misunderstanding the way in which I applied the word "must".

I meant it in this way: there was a fuel gauge on the instrument panel, pretty much right in front of the pilot's line of vision. The AAIB report suggests that this fuel gauge was working properly as designed. Therefore - as I wrote - the pilot must have been able to at least see the fuel gauge (and to see the information it was showing).

Whether the pilot actually looked at the fuel gauge is another matter altogether. I am not saying that the pilot must have looked at the gauge. All I'm saying is that he must have been able to see it. And if the pilot did look at the fuel gauge, there's then the issue of whether or not he comprehended correctly the information it was displaying. Again, I am not saying that the pilot must have been able to do this.

So what I'm saying is this: there was a properly-functioning fuel gauge right in front of the pilot, that he must have been able to see. That's all. And from that, one can draw certain inferences. Either he did not look at the gauge at all, or he looked at it but misinterpreted it, or he looked at it and interpreted it properly, but failed to act properly on that information. I would suggest that any one of these three possibilities is a very bad pilot error.

But the fact remains that the pertinent information was available to be seen (and interpreted) right under the pilot's eyes. Had the fuel gauge been tucked away right in the corner of the instrument panel, or had the gauge been inoperable or malfunctioning, then that would be a different situation altogether. But neither of these was the case. There was a properly-functioning gauge right in front of the pilot, which was telling him in explicit, unequivocal terms that his supply tanks were rapidly running out of fuel. And he must have been able to see that gauge, and to see the information upon it. Whether he actually looked at it (or understood it) though is another matter.

 

[Darth Rotor]

You may be misunderstanding the way in which I applied the word "must".

[Magwa speaks Enlish very well.

Finex.
I am utterly out of ideas on this crash, and am hoping the AAIB can shed more light soon. What I have learned from the folks who fly the EC-135 and who post at PPRuNe has been a real education.

 

[LondonJohn]

The AAIB briefings to families ahead of the report publication have said that the fuel switches were in the "off" position prior to the impact.

http://www.bbc.co.uk/news/uk-scotland-glasgow-west-34599367

I hate to say "I told you so", but.........

 

[Rat]

I hate to say "I told you so", but.........

No, you don't.

 

[Darth Rotor]

The AAIB briefings to families ahead of the report publication have said that the fuel switches were in the "off" position prior to the impact.

http://www.bbc.co.uk/news/uk-scotland-glasgow-west-34599367

I hate to say "I told you so", but.........

Which switches, John?

Hint: there is more than one. What the BBC has in its article is very imprecise. I'll wait for the actual report. Also, if you'd have bothered to venture over the PPRuNe Rotorheads forum, and read the material I pointed you to, you might understand the switchology.

 

[LondonJohn]

Which switches, John?

Hint: there is more than one. What the BBC has in its article is very imprecise. I'll wait for the actual report. Also, if you'd have bothered to venture over the PPRuNe Rotorheads forum, and read the material I pointed you to, you might understand the switchology.

I understand the "switchology" of this aircraft's fuel delivery system properly, thanks very much. What makes you think I don't (and to patronise me about it into the bargain)?

The switches at issue are the switches for the two fuel transfer pumps which transfer fuel from the main tank to the supply tanks.

Can you stick to discussing the topic of this thread rather than making (false) personal accusations about what I might or might not know? Less of the personalisation and hostility from now on, please.

 

[LondonJohn]

It would appear that the investigation is now strictly a human factors matter. The supply pumps were switched off. The question is why they were switched off in the first place. They must have been switched off a long time before the final flameout and ditching, since the supply tanks were dry while there was still ample fuel in the main tank. So, in order, the questions are these:

1) Why did these switches come to be turned off? Was it a total accident (e.g. someone moving around and accidentally knocking the switches? Did the pilot (or anyone else on board) consciously switch to off through some sort of temporary mistake or misidentification? Did the pilot (or anyone else on board) switch them off deliberately and knowingly?

2) Once the switches had gone to "off", and once the aircraft's low-fuel alarm systems started kicking in, what explains the pilot's actions from then on?

3) Why didn't the pilot check the position of these switches? For certain, this would have been on his emergency checklist.

4) Why did the pilot keep on flying towards the centre of a major city - Glasgow - as the warnings got louder and more insistent? He would have had enormous opportunity to set the aircraft down safely in a field or on waste land.

5) Why did the pilot not make any radio communication whatsoever in the 15-odd minutes between the first alarms and the final ditching? He would have had ample time and opportunity to do so, and every indication is that the aircraft was in controlled stable flight - albeit with low-fuel alarms blaring out - during all of this time, so it wasn't as if he was in a prolonged struggle to control the aircraft.

6) Why did the pilot not notice - especially given the loud, explicit and increasing low-fuel alarms - that the supply gauge right in front of him was running close and closer to zero as the supply tanks drained to empty? Even if he had - improperly - tried to "wing it" and get back to base before the fuel ran out, he would have been able to see with high accuracy that he was approaching zero available fuel and should therefore have been able to put the aircraft down safely well before the supply tanks ran totally dry.

7) When the tanks did eventually run dry, why did the pilot not even attempt an autorotate landing? All witness accounts, together with the position of the aircraft and the condition of its rotor blades, shows that no attempt to autorotate was made. Yet at the point of the flameout, the aircraft was easily high enough to perform the manoeuvre.


My best guess is that the AAIB report will address all of these questions, but will leave them unanswered, since there is probably very little way to get any form of accurate. reliable answers to those questions. Regrettably, the only logical reasoning can only (IMO) take three paths: either a) extreme and prolonged incompetence/malpractice on the part of the pilot; b) some sort of pervasive medical incapacitation (though the autopsy on the pilot would very possibly have indicated this if present); c) deliberate act on the part of the pilot (or by another person on board who put himself in control of the pilot and/or aircraft).

We'll know more tomorrow.