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-   -   Police helicopter crashes onto Glasgow pub (https://www.pprune.org/rotorheads/528850-police-helicopter-crashes-onto-glasgow-pub.html)

AnFI 26th Jan 2014 00:28

SS - how do you think a turban ingine operates on fuel foam eg 20% Air by Volume - any idea? Didn't think so.

relevant ? only in as far as an untested condition may occur which may have led to the deaths of 10 people - yes SS/Riga i guess you're right all a bit of a waste of time really, just pointless speculation. Care to address the point with something other than cynical, sneering arrogant indifference? Didn't think so... why bother?

It is patently obvious that, with such a high unuseable fuel quantity, the cockpit situation faced by this pilot may well have left him with an excessively confusing and unexpectedly complex set of actions. Maybe unpredictable issues of timing wrt Governor response rates and pilot action. Everything points to that.
AT LEAST TEST THE SCENARIO - it SHOULD NOT BE DANGEROUS (even for a normal :rolleyes: pilot).

Many combinations of: engine1 suffers reduced output, engine2 increases output (governed for Nr) just as 1st engine 'recovers' pilot has confusing symptoms (popping banging surging symptoms etc), looks in and sees E1 looking good and E2 'heading south'. Shuts down E2 (the good engine) leaving E1 to splutter to death... too confused to put the lever down.

Re-inforced by years of indoctrination from SS and his gang of naive 'experienced' pilots that 2 engines don't fail. "bloggs I'm going to pull One FCL back to idle and when you are stabilized I'll pull the other engine back to simulate a full power loss for an autorotation - do you understand?" - "yes Sir" - "ok bloggs are you ready?" - "yes Sir" - "Practice engine failure 3-2-1-go" "well done Bloggs, back home for chips and medals eh?"
The twin simulated EOLs with power recovery I have seen are a joke and would not make successful arrivals other than in the theoretical world.

1^10-9 IT IS NOT! - Komplexity Kills - KISS baby

This is likely to be another 'systems error' - where certification requirements and tick box training conspire to arrive at another fatal accident.

Bored too now... wait for the report, cease speculation (eh SS?)

(Thank you for the PM support)

RVDT 26th Jan 2014 06:20

AnFI

I had an obscure fuel system issue previously and it turned out to be caused by foaming JetA1 - nearly caused me a major problem.
In the interests of safety can you give us more info or link to the defect report or NAA follow up report?

Nail The Dream 26th Jan 2014 08:24


how do you think a turban ingine operates
Are they the ones used by Air India ? :E


Diesel road fuel has anti-foam additive.
I didn't know the Police used Diesel road fuel in their 135's :rolleyes:


2002 posts now and still nothing productive or positive to say.
Nor me ! - 2002 ? - Someone deleted a few then ! - The above will get the count back up a bit though :ok:

Nail

AnFI 26th Jan 2014 09:55

rvdt ironic your 'location' shows such relevant maths. Not defect, "issue": foam in fuel flow meter leaving overead total - incorrect operation - publishing not appropriate - obviously.
You actually got any thoughts on how this (Sikh) engine runs on 3%, 5%, 12% Air etc? Thought not.:rolleyes:

SilsoeSid 26th Jan 2014 10:14

AnFI (are you really :rolleyes:)

SS - how do you think a turban ingine operates on fuel foam eg 20% Air by Volume - any idea? Didn't think so.

relevant ? only in as far as an untested condition may occur which may have led to the deaths of 10 people - yes SS/Riga i guess you're right all a bit of a waste of time really, just pointless speculation. Care to address the point with something other than cynical, sneering arrogant indifference? Didn't think so... why bother?
How do you spell turbine and engine, any ideas?

Thanks for having a go at me for merely suggesting that all this talk about fuel and fuel systems should be on the specific 135 thread and not on this thread about the Glasgow crash. You said yourself, may have led to ...., there is nothing at all to suggest it would. Besides, if your theory has anything to go on, how did this ac manage to stay up?


PieChaser 26th Jan 2014 10:22

Sid,


..... and at least a thousand must be on the fuel system alone, posts that should be on the 135 thread.
Does that not tell you something?

SilsoeSid 26th Jan 2014 10:26

AnFI (really!)

It is patently obvious that, with such a high unuseable fuel quantity, the cockpit situation faced by this pilot may well have left him with an excessively confusing and unexpectedly complex set of actions. Maybe unpredictable issues of timing wrt Governor response rates and pilot action. Everything points to that.
"Confusing and unexpectedly complex set of actions!"

Taken to the 135 thread :ok:

Arkroyal 26th Jan 2014 10:32

SS
It stayed up because it carried sufficient fuel to maintain feed at extreme attitudes.

I see AnFi' s point.

As the useable fuel is exhausted, depending on tank design, there might be a period where the feed is interrupted momentarily, which might, depending on engine and ignition characteristics, lead to popping and banging as witnessed, and a very confusing problem for the pilot.

As for testing the run dry characteristics on the ground..... pointless. No simulation of the attitude changes in flight.

SilsoeSid 26th Jan 2014 10:36

PC

Sid,


..... and at least a thousand must be on the fuel system alone, posts that should be on the 135 thread.
Does that not tell you something?
Yep, those thousand posts are on the wrong thread!

SilsoeSid 26th Jan 2014 10:50

Thank you Arkroyal, reply on 135 thread :ok:

AnFI 26th Jan 2014 10:55

Shock news!
SS announces Glasgow accident "NOT FUEL SYSTEM RELATED"
(no 'pop' intended, Turban Ingin - spelt the US way!)

Maybe this accident will turn out to be fuel and training system related - seems probable.

SilsoeSid 26th Jan 2014 13:08

AnFI

Shock news!
SS announces Glasgow accident "NOT FUEL SYSTEM RELATED"
(no 'pop' intended, Turban Ingin - spelt the US way!)

Maybe this accident will turn out to be fuel and training system related - seems probable.
Uuum more like, 'SS has suggested that the continuing talk about 135 fuel systems and it's idiosyncrasies, should be on the more specific 135 thread.

overstress 14th Feb 2014 13:14

Special bulletin published today:

http://www.aaib.gov.uk/cms_resources...4%20G-SPAO.pdf

beamender99 14th Feb 2014 13:29

BBC now reporting it too


A police helicopter which crashed on a busy pub in Glasgow last November suffered a double engine failure, apparently as a result of a fuel supply problem, investigators have found.

skadi 14th Feb 2014 13:39

The fuel supply problem was the result of a wrong pump switching. Both transferpumps OFF!!! Additionally the pilot ignored the red FUEL LOW warnings.

skadi

skadi 14th Feb 2014 13:49

I think, my suggestions in post #1429 were not far from reality:

http://www.pprune.org/rotorheads/528...ml#post8215599

skadi

Sky Sports 14th Feb 2014 13:49

Case closed.
This is as good as the final report!

pohm1 14th Feb 2014 14:03


Time for ALL autorotations to be carried out down to the ground in an a/c.
A bit of a moot point really, as practising touch-down autos won't make any difference if you don't enter autorotation in the first place.

P1

Shaggy Sheep Driver 14th Feb 2014 14:09


In particular, the investigation will seek to determine:

Why a situation arose that led to both the helicopter’s engines flaming out when 76 kg of fuel remained in the fuel tank group,

Why no emergency radio transmission was received from the pilot

And why, following the double engine failure, an autorotative descent and flare recovery was not achieved.
I'm surprised they'd expect an emergency transmission; I'd imagine the pilot was far too busy to waste time on pointless radio transmissions.

I wish them luck progressing the other two mysterious points, though. I think they'll need it.

G0ULI 14th Feb 2014 14:14

Redesign Needed Methinks
 
Given that helicopter performance is governed and severely compromised by weight constraints, it seems ludicrous that 85Kg of unuseable fuel has to be carted around. It should be possible to drain pretty much every last drop of fuel from the tanks if necessary.

While there appears to have been a mistake made turning off both transfer pumps, it would make more sense to have a failsafe system where fuel flows to the engines until the fuel tanks are completely empty unless at least two switches per engine are operated to stop flow in event of an emergency such as fire or turbine failure.

My interpretation while reading the report suggests that the flight displays and radio altimeter also failed or became unreliable/inoperable once the second engine spooled down and the generators went off line. The shed load switch was found still in its normal position, so the drain on the battery would have been significant with apparent attempts being made to restart an engine.

Looks like the low fuel warnings were ignored despite all the naysayers earlier in the thread.

So redesign the fuel system and develop a system to automatically shed electrical load when or if both generators drop off line.


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