Police helicopter crashes onto Glasgow pub: final AAIB report
Join Date: May 2001
Location: Scotland
Posts: 26
Likes: 0
Received 0 Likes
on
0 Posts
Originally Posted by [email protected]
Presumably at night as well as by day to provide adequate assurance that no-one will crash into a pub........no, didn't think so.
Heard a rumour that the transfer pumps create interference with the camera or its downlink and it is considered normal to turn them off - this would explain why an experienced pilot cancelled the low fuel warnings several times.
Heard a rumour that the transfer pumps create interference with the camera or its downlink and it is considered normal to turn them off - this would explain why an experienced pilot cancelled the low fuel warnings several times.
Other 135 pilots appear to differ with your opinion but perhaps it is a historic issue that has been engineered out. As I said - a rumour.
The investigation would only have known it if someone told them or they thought to ask the question...did they??? I don't know.
Can someone come up with an explanation for why the low fuel warnings were cancelled so often without further action?
The investigation would only have known it if someone told them or they thought to ask the question...did they??? I don't know.
Can someone come up with an explanation for why the low fuel warnings were cancelled so often without further action?
Tightgit
Crab, I second NR Droop. You can cast that rumour into the same bin that holds the Roswell Alien and Moon landings were fake rumours.
Avoid imitations
Join Date: Nov 2000
Location: Wandering the FIR and cyberspace often at highly unsociable times
Posts: 14,573
Received 422 Likes
on
222 Posts
Hughes500,
I haven't been able to work out why you think any helicopter pilot would do this; it certainly defies logic.
Now the pilot in Glasgow flew twin engines for almost all his career so was it the reverse of my case that happened, i.e. one donk goes pull the lever up second goes natural reaction pull the lever up. Hence the Nr almost nil ???
Handysnacks - you and NrDroop may well be right but why would you repeatedly cancel a fuel low warning unless you were expecting it to happen and were in the habit of automatically cancelling it?
Hi Crab: because of the nose up attitude in the hover, the pumps run dry at low fuel levels. So, you have the option to depart the hover and level the a/c immersing the pumps in fuel and extinguishing the captions, OR, cancelling the captions every few minutes, OR switching the pumps off until you depart the hover at a time to suit you and then switch them back on.............................................if you remember
Tightgit
Crab, if I had to guess, then I would say that he was actually cancelling the red low fuel warning to get rid of the audio gong that would accompany the Low Fuel 1 and/or 2 warning. The red low fuel warning would still be illuminated on the warning panel.
TC - but as I understand it, the pumps have a run-dry capability of 20 mins - more than enough for a short job in the hover, especially when you know you are low on fuel.
It seems that a poor design feature has been 'worked-around' and it has been seen as 'better practice' to turn the pumps off and deliberately cancel the warnings - that is not a healthy ethos.
Handy = yes, I agree, it seems the visual warning captions remain -I don't know if it is a single gong or a repetitive one.
It seems that a poor design feature has been 'worked-around' and it has been seen as 'better practice' to turn the pumps off and deliberately cancel the warnings - that is not a healthy ethos.
Handy = yes, I agree, it seems the visual warning captions remain -I don't know if it is a single gong or a repetitive one.
Crab:
I can only talk for myself and my actions when I did this job.
At night in particular, I wanted always to have a clear caution panel in front of me - in preparation for that unexpected mal;function to flash up.. If the low fuel warnings kept illuminating whilst I was in the hover, I would either (with the permission of the crew who were tracking someone for instance - on camera and didn't want to lose that target), "nod" the cab fwd thus immersing the pick ups in fuel and extinguish the light(s),which gave me breathing space before the run dry caption(s) came back on again - OR, if it was a prolonged hover and I was unable to manouevre temporarily - switch the pumps off. I drilled myself to ensure they came back on again after departing the hover (but as we see - this is not foolproof).
I hasten to add - in mitigation - this was a reasonably rare occurence because this scenario only manifested itself at the edge of my endurance and I would always be of the mindset that this would have to be the last hover, or close to calling it a day (or night).
MLA @ night was higher than day (90kg vs 60Kg from memory) leaving me an adequate barrier between these constantly illuminating captions telling me "low fuel" and actually having low fuel.
Where I struggle with this crash is that the pilot "probably" did what I did - possibly several times over during prolonged hover - each time eating into his night MLA reserve and apparently creeping inexorably closer to his 'actual' minimum useable fuel remaining. It may have been that he was within touching distance of landing at base and this might have given him false security.
The EC135 'density compensator' type fuel capacitors that indicate fuel content weren't in my opinion - rocket science technology. They always gave sporadic changes in the amount remaining, they always 're-adjusted' themselves after landing (level attitude). One couldn't always rely on them to give out exact digital data that was stable. One simply built this into one's processing and planning.
So one would be sitting in the hover for a considerable few minutes (say 10+) and the cops would ask for time remaining airborne and you would go thru the basic maths minus the MLA. Then - after leaving the hover and stabilising in the cruise, one would find that endurance had then 'magically' improved? So there was always this doubt in one's mind as to exactly how much endurance one had - to the minute.
Once the engine(s) shut down - I think this required a totally new mindset. It required the human brain to ramp up from simply being 'aware/alert'.........instantly......to the limits of arousal, bordering on stress and even resignation as the situation gets further out of control.
This is where training by rote kicks in................but one needed to have done the relevant repetitive (EOL) training for that to happen...and I believe this was not the case.
I can only talk for myself and my actions when I did this job.
At night in particular, I wanted always to have a clear caution panel in front of me - in preparation for that unexpected mal;function to flash up.. If the low fuel warnings kept illuminating whilst I was in the hover, I would either (with the permission of the crew who were tracking someone for instance - on camera and didn't want to lose that target), "nod" the cab fwd thus immersing the pick ups in fuel and extinguish the light(s),which gave me breathing space before the run dry caption(s) came back on again - OR, if it was a prolonged hover and I was unable to manouevre temporarily - switch the pumps off. I drilled myself to ensure they came back on again after departing the hover (but as we see - this is not foolproof).
I hasten to add - in mitigation - this was a reasonably rare occurence because this scenario only manifested itself at the edge of my endurance and I would always be of the mindset that this would have to be the last hover, or close to calling it a day (or night).
MLA @ night was higher than day (90kg vs 60Kg from memory) leaving me an adequate barrier between these constantly illuminating captions telling me "low fuel" and actually having low fuel.
Where I struggle with this crash is that the pilot "probably" did what I did - possibly several times over during prolonged hover - each time eating into his night MLA reserve and apparently creeping inexorably closer to his 'actual' minimum useable fuel remaining. It may have been that he was within touching distance of landing at base and this might have given him false security.
The EC135 'density compensator' type fuel capacitors that indicate fuel content weren't in my opinion - rocket science technology. They always gave sporadic changes in the amount remaining, they always 're-adjusted' themselves after landing (level attitude). One couldn't always rely on them to give out exact digital data that was stable. One simply built this into one's processing and planning.
So one would be sitting in the hover for a considerable few minutes (say 10+) and the cops would ask for time remaining airborne and you would go thru the basic maths minus the MLA. Then - after leaving the hover and stabilising in the cruise, one would find that endurance had then 'magically' improved? So there was always this doubt in one's mind as to exactly how much endurance one had - to the minute.
Once the engine(s) shut down - I think this required a totally new mindset. It required the human brain to ramp up from simply being 'aware/alert'.........instantly......to the limits of arousal, bordering on stress and even resignation as the situation gets further out of control.
This is where training by rote kicks in................but one needed to have done the relevant repetitive (EOL) training for that to happen...and I believe this was not the case.
Purveyor of Egg Liqueur to Lucifer
It would seem from the report that most if not all of the systems were found to be working correctly. 'System tested no fault found.'
Funny that in times gone by we used to fix the old TV set by giving it a quick thump
Funny that in times gone by we used to fix the old TV set by giving it a quick thump
Do LPCs on twins get both throttles chopped and an auto rotation to the flare
Last edited by megan; 27th Oct 2015 at 11:28.
TC - it would seem then that the fuel system on the 135 is not fit for purpose in the Police role since that involves a lot of slow speed/hover surveillance.
One of the solutions - the nod - seems to be counter-productive since it sends fuel away from the tanks that directly feed the engines.
Pragmatic solutions to get the job done but all to overcome poor engineering design.
One of the solutions - the nod - seems to be counter-productive since it sends fuel away from the tanks that directly feed the engines.
Pragmatic solutions to get the job done but all to overcome poor engineering design.
TC sez,
Duh? Any successive caution will bring up the MASTER CAUTION no?
WTF? This will NOT extinguish the CAUTION caption "F PUMP" so why bother? Why paint yourself into a corner as well as NOT OPERATING IAW WITH THE RFM.
Granted they have been around for a while but what else is there that is approved and certified? They will "re-adjust" themselves as they are "pitch compensated" and dampened via the CAD software.
Crab sez,
Er no it doesn't. TC is talking about the main tank not the supply tanks.
Do you guys make this sh1t up as you go along?
And when TC is referring to "low fuel" he is referring to a "F PUMP" CAUTION light not a "LOW FUEL" WARNING light I am sure or at least hope so. If there is fuel in the MAIN tank enough to cover the pump which you can determine by your current speed and the quantity on the CAD then the fuel pump shall be ON. Anything else is contrary to the RFM. The procedure in the RFM is to determine if you have a F PUMP failure or not which would be best to know as it may have consequences.
I was discussing this recently with an old school friend who went to planks with QF about 20 years ago after about 12K on helicopters. He mentioned when he was on the 747-400 LAX-SYD it was common to have transfer pump warning lights constantly on approaching SYD after ~ 13 hours. The phenomena is not unique.
in preparation for that unexpected mal;function to flash up
OR, if it was a prolonged hover and I was unable to manouevre temporarily - switch the pumps off.
The EC135 'density compensator' type fuel capacitors that indicate fuel content weren't in my opinion - rocket science technology. They always gave sporadic changes in the amount remaining, they always 're-adjusted' themselves after landing (level attitude).
Crab sez,
One of the solutions - the nod - seems to be counter-productive since it sends fuel away from the tanks that directly feed the engines
Do you guys make this sh1t up as you go along?
And when TC is referring to "low fuel" he is referring to a "F PUMP" CAUTION light not a "LOW FUEL" WARNING light I am sure or at least hope so. If there is fuel in the MAIN tank enough to cover the pump which you can determine by your current speed and the quantity on the CAD then the fuel pump shall be ON. Anything else is contrary to the RFM. The procedure in the RFM is to determine if you have a F PUMP failure or not which would be best to know as it may have consequences.
I was discussing this recently with an old school friend who went to planks with QF about 20 years ago after about 12K on helicopters. He mentioned when he was on the 747-400 LAX-SYD it was common to have transfer pump warning lights constantly on approaching SYD after ~ 13 hours. The phenomena is not unique.
Join Date: Dec 2007
Location: uk
Posts: 13
Likes: 0
Received 0 Likes
on
0 Posts
I keep asking myself, under what circumstances you could keep cancelling the low fuel captions and having no one else in the crew questioning your actions. And I keep coming up with the same scenario.
You tell the crew that we have plenty of fuel in the main tank and that your switching off the transfer pumps because you wish to see or demonstrate when low fuel 1&2 come on. So as the fuel in the supply tanks runs down the low fuel 2 comes on and you cancel it and then cancel it a further 2 times waiting for low fuel 1 to come on, it comes on you reach up and turn what you thought were the transfer pumps on and continue with that one last routine task. The low fuel lights illuminate again, but its OK you tell everyone I've turned the transfer pumps on and the lights will go out shortly. Then it all goes terribly wrong!
You tell the crew that we have plenty of fuel in the main tank and that your switching off the transfer pumps because you wish to see or demonstrate when low fuel 1&2 come on. So as the fuel in the supply tanks runs down the low fuel 2 comes on and you cancel it and then cancel it a further 2 times waiting for low fuel 1 to come on, it comes on you reach up and turn what you thought were the transfer pumps on and continue with that one last routine task. The low fuel lights illuminate again, but its OK you tell everyone I've turned the transfer pumps on and the lights will go out shortly. Then it all goes terribly wrong!
Tightgit
Efish. You cannot cancel the Low Fuel Warning or caution. You can only cancel the audio of the warning or the attention getter for the caution. The captions will still be there on the warning panel or CAD.
Thomas coupling: OR, if it was a prolonged hover and I was unable to manouevre temporarily - switch the pumps off. I drilled myself to ensure they came back on again after departing the hover (but as we see - this is not foolproof).
Purveyor of Egg Liqueur to Lucifer
"I keep asking myself, under what circumstances you could keep cancelling the low fuel captions and having no one else in the crew questioning your actions. And I keep coming up with the same scenario.
You tell the crew that we have plenty of fuel in the main tank and that your switching off the transfer pumps because you wish to see or demonstrate when low fuel 1&2 come on. So as the fuel in the supply tanks runs down the low fuel 2 comes on and you cancel it and then cancel it a further 2 times waiting for low fuel 1 to come on, it comes on you reach up and turn what you thought were the transfer pumps on and continue with that one last routine task. The low fuel lights illuminate again, but its OK you tell everyone I've turned the transfer pumps on and the lights will go out shortly. Then it all goes terribly wrong!"
Apart from the 'demonstrating the Low Fuel warnings' part which imho is utter nonsense, a big flaw in your scenario is that in addition to already having both transfer pump captions, when the prime pumps are switched on (inadvertently) the master caution flashes and the CAD lights up which has to be acknowledged. Additionally, the two Prime Pump cautions will be displayed on the CAD until the pumps are switched off.
However, the biggest flaw in your scenario is that it was the Low Fuel 1 that came on first, twice, before the Low fuel 2 came on and stayed on; I refer to table 3 of page 33.
You tell the crew that we have plenty of fuel in the main tank and that your switching off the transfer pumps because you wish to see or demonstrate when low fuel 1&2 come on. So as the fuel in the supply tanks runs down the low fuel 2 comes on and you cancel it and then cancel it a further 2 times waiting for low fuel 1 to come on, it comes on you reach up and turn what you thought were the transfer pumps on and continue with that one last routine task. The low fuel lights illuminate again, but its OK you tell everyone I've turned the transfer pumps on and the lights will go out shortly. Then it all goes terribly wrong!"
Apart from the 'demonstrating the Low Fuel warnings' part which imho is utter nonsense, a big flaw in your scenario is that in addition to already having both transfer pump captions, when the prime pumps are switched on (inadvertently) the master caution flashes and the CAD lights up which has to be acknowledged. Additionally, the two Prime Pump cautions will be displayed on the CAD until the pumps are switched off.
However, the biggest flaw in your scenario is that it was the Low Fuel 1 that came on first, twice, before the Low fuel 2 came on and stayed on; I refer to table 3 of page 33.
Join Date: Dec 2007
Location: uk
Posts: 13
Likes: 0
Received 0 Likes
on
0 Posts
I doubt there's much ammo there for lawyers, as its a scenario which would be impossible to prove. As far as the indications on the CAD goes. I would assume that he had been operating on NVG and then removed them to operate over the city. One thing that has always annoyed me about the NVG switch is when switching from normal lighting to NVG lighting the CAD and VEMD displays always revert to fully dim and you have to turn the brightness up.
I know pilots do choose to remove the goggles to Relieve the neck strain. Personally I leave mine on as I think it puts you in a much better position to pick that landing site should you need it immediately. Even when operating over a city those black holes that you thought were parks and are actually factory roofs become apparent.
I know pilots do choose to remove the goggles to Relieve the neck strain. Personally I leave mine on as I think it puts you in a much better position to pick that landing site should you need it immediately. Even when operating over a city those black holes that you thought were parks and are actually factory roofs become apparent.