OT: Clutha helicopter fuel indicator could from green to red without warning

[Terry Fields]

The reporting is this article is not good (four different masses/volumes used in reference to the onboard fuel), but a fault has now been found with the fuel indication system.

"Helicopter that crashed into Glasgow pub killing 10 had fuel indicator that could go straight from green to red without warning, admits manufacturer as it issues worldwide safety alert"

"The Police Scotland helicopter crashed into the Clutha pub in Glasgow on November 29, killing three on board and seven in the bar.

Eurocopter issued warning after fault with fuel gauge was discovered

Dial could fall from green to red without any warning

Many of the craft grounded last week amid concerns have resumed flights

Air Accidents Investigation Branch said crashed helicopter still had 95 litres of fuel on board when it fell from the sky

Investigation found 'no evidence of mechanical disruption' "

[Tim Streater]

Does this mean that the pilot would get essentially no warning that he was going to crash, or that the indicator goes to red under some conditions when it should have stayed green? If it's the latter, why did it crash?

[The Other Mike]

Best to go to the horses mouth rather than its arse

[harryagain]

So instruments and a combination of two errors as I said. They are supposed to dip the tank before setting off, not rely on instruments for this very reason.

[harryagain]

It means the pilot was a tosser for not dipping the tank & just relying on the instrument/fuel guage before setting off. Exraordinary, he was supposed to be ex-military. It is supposed tobe checked by both ground crew and pilot in military/commercial operations. Got used to the ground crew doing th dirty work I expect.

[Nightjar]

What it means, looking at the Eurocopter notice, is that the fuel gauge may over read the fuel in the supply tanks. However, the low fuel (red) indicator will still operate properly and the pilot needs to carry out the appropriate actions when the red warning light appears. There will still be fuel in the tanks when it does - there would be little point in a light that tells you that you have run out of fuel and can't do anything about it - and the engines should still run out sequentially, a few minutes apart, not simultaneously if the pilot does nothing.

We won't know that until the AAIB report. However, I still think compressor stall to be the most probable cause on the basis of the evidence released.

Colin Bignell

[John Williamson]

As the discovered problem leads to an inaccurately *low* fuel indication, and the records show that when the 'copter took off from base it had *at least* 400kg of fuel on board, and it has been proven that there were still 95 litres of this (Above the new maker's recommendation of 90 litres minimum)on board after impact, how would dipping the tanks have helped? Presumably you would claim that someone faked the fuelling records? I'll admit that the pilot might not actually have been present and watching the fuel go into the tank, as I don't know how the setup there works.

Also, the Daily Fail not mentioning that the tanks were dipped doesn't mean that the flight manual procedures weren't followed.

I've just pointed out to someone on a forum the perils of relying on the Daily Mail website as a source of news.

I see that the latest findings quoted above indicate that not only were the rotors stationary at impact, so were both engine turbines. Maybe someone wired an engine kill switch to the fuel transfer pump wiring, or put a time delayed relay on board to shut down the engines. That makes as much sense as a lot of the theories I've read here.

[Andy Cap]

I don't get the point you're making, in that there was 95 litres of fuel onboard, so what would dipping have achieved?

[John Williamson]

What it means is that the fuel warning light goes from showing green for okay to red for "You have no fuel" without first showing the yellow light to say "You are running low on fuel, please land at your earliest convenience". When the red bingo light shows, a trained pilot will carry out the procedure in the manual, and land as soon as possible using autorotation if it turns out to be needed. In any case, the rotors and engines won't just stop with no warning as one engine will stop first, giving a warning that the other one won't be far behind. (According to the rotorheads and other published information)

We should remember that this type of helicopter has a good safety record, considering just how many of them are flying, and how many hours a year they each fly, and under what circumstances. They are used for emergency work, which often means flying in weather conditions that would ground most other pilots.

I take it you have incontrovertible proof that the pilot didn't dip the tank before take-off? Maybe you were there and forgot to bollock him? Or you've seen a video of the fuelling process and the pilot doing the preflight checks? It's not just the person you insult that can sue you, so can his family.

[John Williamson]

It would have given someone the chance to stand on the skid in mid air, wielding a dipstick, of course.

Harry seems to have a theory that all three fuel gauges were reading high, and that the warning light failed to light, and that the pilot failed to notice that one engine had already run out of fuel. I'm not sure how he explains the 95 litres of fuel that they drained out of the wreck.

[Adrian]

It's also the AAIB, since Harry's accusing them of lying in the interim report that said 400kg was put in before take off. About 500 litres, and they also explicitly stated that 95l, about 20% of what went in, was pumped out after the crash.

But since when do such little insignificant details make a difference to Harry? All Hail The New Duhg.

[Nightjar]

You do write some total rubbish Harry. The aircraft had 400kgs of fuel aboard when it took off. The reported fault affects only the gauges for the supply tanks which, between them can hold about 74kgs. You also have no idea whether the pilot dipped the tanks or not, nor of how accurate dipping is on this particular aircraft.

Colin Bignell

[GB]

For this to be the reason for the Clutha accident, the pilot apparently needs to see the red light and decide to switch both engines off.

Have I got that right? Anyway, it makes no sense.

[Bill Wright]

Why should a faulty gauge cause the engines to stop?

Bill

[The Natural Philosopher]

well yes.

Everything is consistent with both engines stopping and autorotation not happening correctly.

The two questions are 'why?' in each case.

Was the pilot conscious?

I.e. suppose something took out both engines *and* the pilot? what would then happen?

[F]

Absolute bollocks as usual.

When you're feeling lonely, don't post your usual off-topic and inaccurate rubbish here, ring 0800 4708090. They'll talk to you for as long as you want, and it's free.

[GB]

My wife volunteered for the Samaritans. They put her on the Brenda line. (Google it.)

[Martin Brown]

Looks like it fails to go amber when it should and then hits red suddenly without warning and possibly rather late in the day leaving a very limited time for action before the shit at the bottom of the fuel tank goes into the engines (or more likely clogs the fuel filters).

A red light to say that your engines have just failed isn't a lot of use, but by the sounds of it that may have been what happened. We will never know for sure because they did not have a black box recorder to show the actual timeline of events. AAIB will have to work very hard!

It would be consistent with what was observed on the night and the total absence of any mayday call. Solid state circular buffer cockpit voice recorders must be made mandatory for all aircraft in future.

The other interpretation of the report is that the fuel warning light could be red (and genuine) with an apparent fuel indication of "plenty".

Reading between the lines of the above report (last sentence).

Hard to understand how there was 95L left in the main tank if it failed catastrophically on both engines by running a fuel tank dry. ISTR they are supposed to fail one at a time and it will fly on one engine.

[Adrian]

How do choppers pick fuel up from the tanks? The reason I ask is that so many people trot similar out for cars, despite the tanks in cars always picking fuel up from the same place - the bottom - of the tank.

The only way that a low level can "clog the filters" is if the s**te is floating on the top.

[Tim+]

Better still, join the pprune forum and post your theories there. I'm sure all the helicopter pilots there would be fascinated to hear them.

Tim