Police helicopter crashes onto Glasgow pub: final AAIB report
Join Date: Feb 2005
Location: On the green bit near the blue wobbly stuff
Posts: 674
Likes: 0
Received 1 Like
on
1 Post
The pilot has to keep the aircraft safe, but the mission is the whole reason that the aircraft is there in the first place. The pilot cannot be isolated from the mission, as you will lose a lot of the team effectiveness of working together as a crew. The crew has to be completely integrated on the task, otherwise the helicopter will not be in the right place to see the target and achieve the mission.
Yes the workload is high at times, and prioritisation is very important if and when there is a conflict between safety and mission effectiveness. That is why police pilots really need to have a shedload of experience before they are recruited into this role.
Yes the workload is high at times, and prioritisation is very important if and when there is a conflict between safety and mission effectiveness. That is why police pilots really need to have a shedload of experience before they are recruited into this role.
Just to clarify a few things -
In the configuration of the pumps that was evident after the accident 4 CAD captions would/should have been illuminated?
FWD F PUMP
AFT F PUMP
PRIME PUMP (BOTH)
As to the Emergency Shed Bus switch being inaccessible or hard to find?
If you actually READ the RFM you would have activated it to test for a fuse failure in the EMB prior to each flight? So it should be second nature.
A note - it is not in the pre-start checks but in the pre-flight check.
In the configuration of the pumps that was evident after the accident 4 CAD captions would/should have been illuminated?
FWD F PUMP
AFT F PUMP
PRIME PUMP (BOTH)
As to the Emergency Shed Bus switch being inaccessible or hard to find?
If you actually READ the RFM you would have activated it to test for a fuse failure in the EMB prior to each flight? So it should be second nature.
A note - it is not in the pre-start checks but in the pre-flight check.
RVDT, think you miss the point...if both engines/transmission fail,both your hands /feet should be occupied in flying the aircraft,and sustaining RRPM..nothing else matters..except your life..!
This was not a set-up in a Sim,or a practice from 2000` into wind on a fine day,having briefed...
As I said in an earlier post any emergency `switching` should be in easy reach of your hands,ie floats,or clear/dump weapons;in this case your lights and rad .alt should be on the `Essential busbar`....
This was not a set-up in a Sim,or a practice from 2000` into wind on a fine day,having briefed...
As I said in an earlier post any emergency `switching` should be in easy reach of your hands,ie floats,or clear/dump weapons;in this case your lights and rad .alt should be on the `Essential busbar`....
Join Date: Nov 2015
Location: UK
Posts: 22
Likes: 0
Received 0 Likes
on
0 Posts
CAD Caution and Dispays
In the obvious scenario which I have presented before in my first post, I BELIEVE:
At the time of LOW FUEL Warnings, there would be no F PUMP FWD or AFT cautions as the transfer pumps had been switched off whilst dry running iaw normal procedure.
On leaving the hover at Dalkeith the F PUMP FWD switch was simply forgotten to be turned on again, after having been dry running so there is no reminder caution appearing. This has happened once or twice in just my flying career, hopping between hover or slow speed flight and forward flight between tasks.
Once in forward flight the F PUMP AFT caution appeared as it was running dry then the F PUMP AFT switch was switched off iaw normal procedure (but forgetting that he had forgotten to switch the F PUMP FWD switch back on in Dalkeith). Therefore, as each pump had been turned off at a time of dry running, subsequent emersion in fuel does not activate a F PUMP FWD or AFT caution again.
Unfortunately the GNWEM/GXMI fault does not present a FUEL Caution either, which I'm 100% convinced, that if it had appeared the transfer pumps would have been checked and switched back on at that point. Remember that with correctly indicating supply tank indications, the supply tanks would have also dropped down from normal levels and this is really noticeable! Obvious in fact, and these clues would never be missed.
Every police crew I have ever flown with would question a caution, initially flashing until acknowledged, and wouldn't be happy with a caution or warning remaining on unless justified that it was ok.
I have had a ROTOR RPM warning come on intermittently in flight, then stay on whilst in flight. I was of course able to understand what was happening and justify to my passenger that I could continue the flight to land as soon as practicable. So I dismissed that warning as being false.
With the fuel sensor fault of GNWEM/GXMII, the supply tanks would show full at 90 kgs throughout. It is possible that the main tank sensors were affected also, I think they were probably ok, and in my scenario, even if the main tank sensors are working normally, the total fuel load at the point of LOW FUEL Warnings could have easily been considered normal, thus effectively backing up a dismissal of the LOW FUEL Warnings. Sadly, even a check of the transfer pumps may not have happened at the LOW FUEL Warning stage, as they had to be on if there was full fuel in the supply tanks - unless you had the GNWEM/GXMII fault!!! I have 100% believe in this course of events, but will never be able to prove it, and I know noone is able to disprove it.
At the time of the first engine failure, No2 Engine, there may have initially appeared a FUEL PRESSure caution as the last bits of fuel are being sucked up, so he may have switched on his No2 Prime Pump, or may just have simply gone for both anyway to be quick. But, according to first responder photos though, there was only the 1 switch on but we are not told which one.
Of course when the engine runs dry of fuel, ENG FAIL, ENG OIL P, FUEL PRESS, GEN DISCON cautions.
I'm suspecting by the time of the first ENGINE rundown, and dealing with that, a possible look at full supply tanks but still the same indication of 76kgs.....**** there goes my other engine......
Prove to me I'm wrong??
At the time of LOW FUEL Warnings, there would be no F PUMP FWD or AFT cautions as the transfer pumps had been switched off whilst dry running iaw normal procedure.
On leaving the hover at Dalkeith the F PUMP FWD switch was simply forgotten to be turned on again, after having been dry running so there is no reminder caution appearing. This has happened once or twice in just my flying career, hopping between hover or slow speed flight and forward flight between tasks.
Once in forward flight the F PUMP AFT caution appeared as it was running dry then the F PUMP AFT switch was switched off iaw normal procedure (but forgetting that he had forgotten to switch the F PUMP FWD switch back on in Dalkeith). Therefore, as each pump had been turned off at a time of dry running, subsequent emersion in fuel does not activate a F PUMP FWD or AFT caution again.
Unfortunately the GNWEM/GXMI fault does not present a FUEL Caution either, which I'm 100% convinced, that if it had appeared the transfer pumps would have been checked and switched back on at that point. Remember that with correctly indicating supply tank indications, the supply tanks would have also dropped down from normal levels and this is really noticeable! Obvious in fact, and these clues would never be missed.
Every police crew I have ever flown with would question a caution, initially flashing until acknowledged, and wouldn't be happy with a caution or warning remaining on unless justified that it was ok.
I have had a ROTOR RPM warning come on intermittently in flight, then stay on whilst in flight. I was of course able to understand what was happening and justify to my passenger that I could continue the flight to land as soon as practicable. So I dismissed that warning as being false.
With the fuel sensor fault of GNWEM/GXMII, the supply tanks would show full at 90 kgs throughout. It is possible that the main tank sensors were affected also, I think they were probably ok, and in my scenario, even if the main tank sensors are working normally, the total fuel load at the point of LOW FUEL Warnings could have easily been considered normal, thus effectively backing up a dismissal of the LOW FUEL Warnings. Sadly, even a check of the transfer pumps may not have happened at the LOW FUEL Warning stage, as they had to be on if there was full fuel in the supply tanks - unless you had the GNWEM/GXMII fault!!! I have 100% believe in this course of events, but will never be able to prove it, and I know noone is able to disprove it.
At the time of the first engine failure, No2 Engine, there may have initially appeared a FUEL PRESSure caution as the last bits of fuel are being sucked up, so he may have switched on his No2 Prime Pump, or may just have simply gone for both anyway to be quick. But, according to first responder photos though, there was only the 1 switch on but we are not told which one.
Of course when the engine runs dry of fuel, ENG FAIL, ENG OIL P, FUEL PRESS, GEN DISCON cautions.
I'm suspecting by the time of the first ENGINE rundown, and dealing with that, a possible look at full supply tanks but still the same indication of 76kgs.....**** there goes my other engine......
Prove to me I'm wrong??
Join Date: Nov 2015
Location: UK
Posts: 22
Likes: 0
Received 0 Likes
on
0 Posts
Shed Bus Switch Practice
Good point about the shed bus switch and it being second nature......
It's activated on first flight of the day along with an autopilot test, but subsequently, it does not have to be tested for Police quick starts to urgent tasking iaw Operating Manual.
May be a good thing to practice more often though, I agree, and certainly for non urgent tasks. Its still in a pretty poor position really though. I also do have to say double engine failure, very unlikely, but double generator failure, more likely but not quite so urgent to get to it. So yes, the aircraft was not designed so well for the less likely scenario, but we weren't supposed to have a twin engine fuel starvation within 32 secs either.
That is a good point anyway and one which can easily be taken further.
It's activated on first flight of the day along with an autopilot test, but subsequently, it does not have to be tested for Police quick starts to urgent tasking iaw Operating Manual.
May be a good thing to practice more often though, I agree, and certainly for non urgent tasks. Its still in a pretty poor position really though. I also do have to say double engine failure, very unlikely, but double generator failure, more likely but not quite so urgent to get to it. So yes, the aircraft was not designed so well for the less likely scenario, but we weren't supposed to have a twin engine fuel starvation within 32 secs either.
That is a good point anyway and one which can easily be taken further.
8peiced,
"At the time of LOW FUEL Warnings, there would be no F PUMP FWD or AFT cautions as the transfer pumps had been switched off whilst dry running iaw normal procedure.*"
That is incorrect. If the pumps have been switched off after the appearance of the caption due to a run dry event, then the caption will remain lit because the pumps are off. If the captions are not lit due to run dry and the pilot switches them off, there will be a 3 minute delay before the captions appear.
Only re-immersion in fuel and putting the pumps on will cause the captions to clear.
"At the time of LOW FUEL Warnings, there would be no F PUMP FWD or AFT cautions as the transfer pumps had been switched off whilst dry running iaw normal procedure.*"
That is incorrect. If the pumps have been switched off after the appearance of the caption due to a run dry event, then the caption will remain lit because the pumps are off. If the captions are not lit due to run dry and the pilot switches them off, there will be a 3 minute delay before the captions appear.
Only re-immersion in fuel and putting the pumps on will cause the captions to clear.
Join Date: Nov 2015
Location: UK
Posts: 22
Likes: 0
Received 0 Likes
on
0 Posts
Sorry yes you are correct
Yes the Fwd and Aft cautions are there as you have correctly switched off the pumps, but the other should have been turned on during forward flight as you have the pump caution and fuel in the main tank if indicating correctly.
So the cautions don't raise the alarm bells they should as I believe the supply tanks are apparently full with this sensor fault.
Sorry for confusion.
And of course we are told that both VEMDs and the CAD too are serviceable - as of course a CAD failure would lose the fuel Pump Cautions, but he would also lose Fuel indication, at which point I'm sure they would having been landing on anyway, so definitely not that.
So the cautions don't raise the alarm bells they should as I believe the supply tanks are apparently full with this sensor fault.
Sorry for confusion.
And of course we are told that both VEMDs and the CAD too are serviceable - as of course a CAD failure would lose the fuel Pump Cautions, but he would also lose Fuel indication, at which point I'm sure they would having been landing on anyway, so definitely not that.
Last edited by 8Pieced; 10th Nov 2015 at 14:34. Reason: Fuzzy eyes again and aching head 😀
Join Date: Dec 2013
Location: South Coast, UK
Age: 67
Posts: 55
Likes: 0
Received 0 Likes
on
0 Posts
8Pieced:
With the fuel sensor fault of GNWEM/GXMII, the supply tanks would show full at 90 kgs throughout. It is possible that the main tank sensors were affected also, I think they were probably ok, and in my scenario, even if the main tank sensors are working normally, the total fuel load at the point of LOW FUEL
But to be clear, for your theory to be feasible both supply tank fuel sensors would need to have suffered the same fault at the same time, correct?
With the fuel sensor fault of GNWEM/GXMII, the supply tanks would show full at 90 kgs throughout. It is possible that the main tank sensors were affected also, I think they were probably ok, and in my scenario, even if the main tank sensors are working normally, the total fuel load at the point of LOW FUEL
But to be clear, for your theory to be feasible both supply tank fuel sensors would need to have suffered the same fault at the same time, correct?
Join Date: Nov 2015
Location: UK
Posts: 22
Likes: 0
Received 0 Likes
on
0 Posts
GNWEM and GXMII had that?
Yes I suppose GXMII and GNWEM both had that fault, so it doesn't seem impossible to me. I haven't heard of any other machine having 1 low fuel warning activate due to a single supply tank showing full? Or has that happened to someone else too? Would be interesting to hear?
Join Date: Sep 2007
Location: Goathland
Posts: 125
Likes: 0
Received 0 Likes
on
0 Posts
Hi, G0ULI
Yes, I understand what you are saying and I'm quite open minded about it, but most - actually all tantalum capacitors I've used are of the sintered design, making them actually quite robust, I know there are wet versions, but in my experience they aren't used much due to cost.
If this cap was damaged by high g force, were there any more of them damaged - the report makes no mention of any, the circuit board most probably had many such capacitors on it (if it was an audio amp at least), and just one fails due to g force, sorry I'm not buying that?
I'm betting it was a surface mount PCB, somebody just loaded the wrong voltage cap into the auto placement machine, easily done, done it myself.
I would still like to see a circuit diagram and wiring diagram, I'm possibly a bit sceptical, but I just like to tie up loose ends...
Kev.
ps. had a quick look at some cap specs, first one I found for a cheap version could withstand a shock of 70g at 100Hz for 8 hours...
Yes, I understand what you are saying and I'm quite open minded about it, but most - actually all tantalum capacitors I've used are of the sintered design, making them actually quite robust, I know there are wet versions, but in my experience they aren't used much due to cost.
If this cap was damaged by high g force, were there any more of them damaged - the report makes no mention of any, the circuit board most probably had many such capacitors on it (if it was an audio amp at least), and just one fails due to g force, sorry I'm not buying that?
I'm betting it was a surface mount PCB, somebody just loaded the wrong voltage cap into the auto placement machine, easily done, done it myself.
I would still like to see a circuit diagram and wiring diagram, I'm possibly a bit sceptical, but I just like to tie up loose ends...
Kev.
ps. had a quick look at some cap specs, first one I found for a cheap version could withstand a shock of 70g at 100Hz for 8 hours...
Join Date: Nov 2015
Location: UK
Posts: 22
Likes: 0
Received 0 Likes
on
0 Posts
Fortyodd - I think you may just have solved the Puzzle!!!!!
FortyOdd I think you have just helped me to solve the mystery!!!! I wish I could shake your hand now!!!!!
I was driving along this evening thinking, 8Pieced you silly ****, how could you forget that you still have the F PUMP FWD or the F PUMP AFT cautions staying on the CAD at the LOW FUEL Warning stage for GSPAO, but seemingly I seem to have not been acknowledging them anymore? See my post 349 to illustrate my apparent stupidity - I promise I will not edit the post.
Then it struck me that hovering, changing to forward flight etc, in the police role, we are getting Fuel Pump cautions all the time, acknowledging them as they flash, switching the pump off then being 'rewarded' by confining that 'ok to have' caution to the top middle of our CAD, then flying around with our 'Ok to have' cautions. So we effectively have a part of the CAD to which we have become used to seeing these cautions, and hence have become almost invisible, and perfectly normal. That is the key here, so imagine what may happen with a fault such as GNWEM/GXMII?
If you can't imagine the significance, reread my post 278 in which I have just edited an important bit in CAPITALS, to reflect my apparent stupidity.
Or I'll quickly explain here. So the F PUMP FWD caution appears over Dalkeith (I'm still absolutely sure that I can prove this could happen in hover attitude at 200 kgs total). The caution is cancelled and then sits as an 'ok to have ' caution on the top middle part of the CAD.
During transit back to Glasgow, the F PUMP AFT caution is activated, we only see the flashing caution, so simply acknowledge it, look up, switch off the pump and don't necessarily recheck the CAD, so we now have the two cautions still sitting in the 'ok to have' area at the top middle part of the CAD, where they could go unnoticed but the next safety kicks in.
So with a correctly indicating fuel system we will get decreasing supply tank levels, which I would say would become noticeable, but even if not, you will then get a flashing FUEL caution. At this point a quick look at fuel supply tank levels will tell you that you have forgotten to put the transfer pumps back on.
But with a faulty fuel system like GNWEM/GXMII you won't have a flashing FUEL caution to acknowledge, and your supply tanks will indicate full and guess what, the two F PUMP cautions are still sitting in the 'Ok to have' area on the CAD!
I rest my case.....how bloody scary?!?!
Once firmly dismissing those Low Fuel Warnings, and lets say it took 1 - 2 minutes to convince the crew that this was ok, the fuel would not have dropped by much in reality 5 kgs, hardly noticeable, needing a bit longer to see that the main tank gauge isn't changing....
Thankyou again Fortyodd for kicking my ass!!
I was driving along this evening thinking, 8Pieced you silly ****, how could you forget that you still have the F PUMP FWD or the F PUMP AFT cautions staying on the CAD at the LOW FUEL Warning stage for GSPAO, but seemingly I seem to have not been acknowledging them anymore? See my post 349 to illustrate my apparent stupidity - I promise I will not edit the post.
Then it struck me that hovering, changing to forward flight etc, in the police role, we are getting Fuel Pump cautions all the time, acknowledging them as they flash, switching the pump off then being 'rewarded' by confining that 'ok to have' caution to the top middle of our CAD, then flying around with our 'Ok to have' cautions. So we effectively have a part of the CAD to which we have become used to seeing these cautions, and hence have become almost invisible, and perfectly normal. That is the key here, so imagine what may happen with a fault such as GNWEM/GXMII?
If you can't imagine the significance, reread my post 278 in which I have just edited an important bit in CAPITALS, to reflect my apparent stupidity.
Or I'll quickly explain here. So the F PUMP FWD caution appears over Dalkeith (I'm still absolutely sure that I can prove this could happen in hover attitude at 200 kgs total). The caution is cancelled and then sits as an 'ok to have ' caution on the top middle part of the CAD.
During transit back to Glasgow, the F PUMP AFT caution is activated, we only see the flashing caution, so simply acknowledge it, look up, switch off the pump and don't necessarily recheck the CAD, so we now have the two cautions still sitting in the 'ok to have' area at the top middle part of the CAD, where they could go unnoticed but the next safety kicks in.
So with a correctly indicating fuel system we will get decreasing supply tank levels, which I would say would become noticeable, but even if not, you will then get a flashing FUEL caution. At this point a quick look at fuel supply tank levels will tell you that you have forgotten to put the transfer pumps back on.
But with a faulty fuel system like GNWEM/GXMII you won't have a flashing FUEL caution to acknowledge, and your supply tanks will indicate full and guess what, the two F PUMP cautions are still sitting in the 'Ok to have' area on the CAD!
I rest my case.....how bloody scary?!?!
Once firmly dismissing those Low Fuel Warnings, and lets say it took 1 - 2 minutes to convince the crew that this was ok, the fuel would not have dropped by much in reality 5 kgs, hardly noticeable, needing a bit longer to see that the main tank gauge isn't changing....
Thankyou again Fortyodd for kicking my ass!!
Last edited by 8Pieced; 10th Nov 2015 at 21:12. Reason: speeling ;-)
Join Date: Nov 2015
Location: UK
Posts: 22
Likes: 0
Received 0 Likes
on
0 Posts
I will give it a rest now, yes TC.
I logged on hear a few years back and was pretty unimpressed, these forums are sometimes disrespectful, but I suppose make people think.
If something similar to this ever happens to me, I would simply wish that you don't give up if you have that niggling doubt, and don't just let something be brushed under the carpet. I have never said that I could have done any better than this crew did, and that's what is so scary to me. RIP.
If something similar to this ever happens to me, I would simply wish that you don't give up if you have that niggling doubt, and don't just let something be brushed under the carpet. I have never said that I could have done any better than this crew did, and that's what is so scary to me. RIP.
Join Date: Dec 2006
Location: UK and MALTA
Age: 61
Posts: 1,297
Likes: 0
Received 18 Likes
on
4 Posts
8pieced I rarely concur with TC but on this occasion he is right.
Quite how you can feel justified in the realisation that having two captions on the panel clearly indicating that your transfer pumps are off with a couple of hundred kilos lef in your tanks is reasonable speaks volumes for the level of knowledge you have had of how your rather simple system works.
We have 4 pumps, five jet pumps and 11 tanks working the same full feeder tank system. No one I am aware of on this type has managed to "starve" the engines.
You have not discovered the holy grail. You have just been forced to recognise how poor your knowledge and awareness has been. If that smarts a bit suck it up cos other people's live depend on you knowing exactly what the indications, cautions and warning backstops mean in your helicopter.
I do however admire your candour is fessing up. Now look at all the other systems and make sure you know how they also work.
Quite how you can feel justified in the realisation that having two captions on the panel clearly indicating that your transfer pumps are off with a couple of hundred kilos lef in your tanks is reasonable speaks volumes for the level of knowledge you have had of how your rather simple system works.
We have 4 pumps, five jet pumps and 11 tanks working the same full feeder tank system. No one I am aware of on this type has managed to "starve" the engines.
You have not discovered the holy grail. You have just been forced to recognise how poor your knowledge and awareness has been. If that smarts a bit suck it up cos other people's live depend on you knowing exactly what the indications, cautions and warning backstops mean in your helicopter.
I do however admire your candour is fessing up. Now look at all the other systems and make sure you know how they also work.
To reiterate on some of the "shock horror" stories put forward about landing lights and RAD ALT.
Contrary to what some have quoted the LANDING LIGHT always works so long as the BAT MASTER is on.
The steerable SEARCH LIGHT is on the SHED BUS.
There is a rather large placard plastered all over the panel that says in "Autorotation" RA Not Active. It has been there
since before this accident or at least on the one I fly.
This is a twin engine helicopter - if you want to operate it as a single then.......... I guess it's up to you but hardly
wise or legal for that matter.
The question that remains is how someone managed to "paint themselves into a corner" which just shouldn't happen.
The probability of what happened is or should be highly improbable and is evidenced in how many million flight hours?
If the probability of a double engine failure, low level, at night over a built up area was high then things would be done
differently no?
Contrary to what some have quoted the LANDING LIGHT always works so long as the BAT MASTER is on.
The steerable SEARCH LIGHT is on the SHED BUS.
There is a rather large placard plastered all over the panel that says in "Autorotation" RA Not Active. It has been there
since before this accident or at least on the one I fly.
This is a twin engine helicopter - if you want to operate it as a single then.......... I guess it's up to you but hardly
wise or legal for that matter.
The question that remains is how someone managed to "paint themselves into a corner" which just shouldn't happen.
The probability of what happened is or should be highly improbable and is evidenced in how many million flight hours?
If the probability of a double engine failure, low level, at night over a built up area was high then things would be done
differently no?
Join Date: Dec 2013
Location: Norfolk
Age: 67
Posts: 1
Likes: 0
Received 0 Likes
on
0 Posts
The problem is a fuel system design that requires pilot intervention so frequently as to render such actions a reflex, without conscious thought.
Only two warning captions should be needed in a well designed system, fuel system fault (e.g. pump failure or blockage) and low fuel.
The pilot's action in either case would be to carry out a precautionary landing.
Only two warning captions should be needed in a well designed system, fuel system fault (e.g. pump failure or blockage) and low fuel.
The pilot's action in either case would be to carry out a precautionary landing.
Join Date: Aug 2002
Location: Craggy Island
Posts: 69
Likes: 0
Received 0 Likes
on
0 Posts
Don't be nasty to 8, he has now put forward the potential scenario thAt many of us suggested soon after the accident. Better late than never.
If people don't understand the system, it just shows how random posts by random people can skew fact,
But people, please remember, this scenario is still only our theory, we could be wrong. So prefix all by saying 'in my opinion', it's NOT fact
If people don't understand the system, it just shows how random posts by random people can skew fact,
But people, please remember, this scenario is still only our theory, we could be wrong. So prefix all by saying 'in my opinion', it's NOT fact
Purveyor of Egg Liqueur to Lucifer
Concur with TC & DB and to add that, with eight years and more than 1500hrs and still flying the 135, there has in my mind never been an 'alright to have' caution and I would be amazed if anyone flew with that attitude.
As mentioned in the report on page 19, and something that I took a look at in our own SRP's covering the last couple of years, landing fuel levels are rarely at the levels where the pump cautions would have illuminated during flight, so it's not such a common action to turn the tx pumps off than we are being led to believe here, certainly imho not regular enough to be dismissed as 'alright to be on'.
For me it would be abnormal for the supply tanks to remain indicating full (47/43) all the time during a transit, especially with 200 kg total, which in itself gives me something to be 'aroused' about and looking at the gauges. So when in 8's scenario the Aft caution comes on, the realisation that both pumps are now off would be quite clear, not to mention the static main content indication. Do you really believe that a caution would be acknowledged during a transit over dark barren countryside, with not a lot else to think about, without looking at what that caution was for? I think not.
Is 8 telling me that I am the only helicopter pilot flying around thinking the old mantra that "If nothing is going wrong, it's just about to?"
Perhaps my own 'I learnt about fuel appreciation from that' has put me in a different mindset when I go flying, it's certainly different to 8's.
As mentioned in the report on page 19, and something that I took a look at in our own SRP's covering the last couple of years, landing fuel levels are rarely at the levels where the pump cautions would have illuminated during flight, so it's not such a common action to turn the tx pumps off than we are being led to believe here, certainly imho not regular enough to be dismissed as 'alright to be on'.
For me it would be abnormal for the supply tanks to remain indicating full (47/43) all the time during a transit, especially with 200 kg total, which in itself gives me something to be 'aroused' about and looking at the gauges. So when in 8's scenario the Aft caution comes on, the realisation that both pumps are now off would be quite clear, not to mention the static main content indication. Do you really believe that a caution would be acknowledged during a transit over dark barren countryside, with not a lot else to think about, without looking at what that caution was for? I think not.
Is 8 telling me that I am the only helicopter pilot flying around thinking the old mantra that "If nothing is going wrong, it's just about to?"
Perhaps my own 'I learnt about fuel appreciation from that' has put me in a different mindset when I go flying, it's certainly different to 8's.
The pilot's action in either case would be to carry out a precautionary landing.
The problem is a fuel system design that requires pilot intervention so frequently as to render such actions a reflex, without conscious thought.
Join Date: Nov 2015
Location: UK
Posts: 22
Likes: 0
Received 0 Likes
on
0 Posts
We can't have safety without honesty, never forget that please.
We must have a culture where people can still ask a silly question without getting stamped on, or report something 'silly' which they may have done. If enough data collected then manufacturers may decide to change things.
Millions of hours have been flown on this type, but I bet thousands of similar pump management errors have probably gone unreported.
The other type I fly (same manufacturer) has 4 fuel switches, switched on for flying, switched off for when finished flying - simple, plus a fuel transfer. An auto system sounds sensible to me and solves fuel flow over issues - both switches should probably be on prior to landing at lower fuel states (below 90 kgs) in case of flow over, as in my opinion as there could still be unused fuel in the main tank.
Of course when I dry run a pump at lower fuels (below 200kgs in hover for F PUMP FWD or below about 140 kgs for F PUMP AFT in forward flight) it is absolutely 'ok to have' a F PUMP caution on my CAD - I acknowledged the flashing caution, switched off the respective pump so I put the caution there on my panel. So yes I still believe it is 'ok to have'. At lower fuel states (below 90kgs) you will have both pumps running dry, so iaw procedure they then should both be off, unless you have fuel in the main tank. So 2 Fuel Pump cautions is a picture which might have become 'ok to have' on a 135 if you regularly conduct landings to for instance 60 kgs, which was a previous Day FRF prior to this accident.
If pilots are leaving the dry running pumps then are using work arounds.
Lastly, I think the system is straight forward with a great catch all FUEL caution and Supply Tanks displays - IF THEY ARE WORKING PROPERLY. In my opinion I believe that GSPAO had the same fault as GNWEM.
We must have a culture where people can still ask a silly question without getting stamped on, or report something 'silly' which they may have done. If enough data collected then manufacturers may decide to change things.
Millions of hours have been flown on this type, but I bet thousands of similar pump management errors have probably gone unreported.
The other type I fly (same manufacturer) has 4 fuel switches, switched on for flying, switched off for when finished flying - simple, plus a fuel transfer. An auto system sounds sensible to me and solves fuel flow over issues - both switches should probably be on prior to landing at lower fuel states (below 90 kgs) in case of flow over, as in my opinion as there could still be unused fuel in the main tank.
Of course when I dry run a pump at lower fuels (below 200kgs in hover for F PUMP FWD or below about 140 kgs for F PUMP AFT in forward flight) it is absolutely 'ok to have' a F PUMP caution on my CAD - I acknowledged the flashing caution, switched off the respective pump so I put the caution there on my panel. So yes I still believe it is 'ok to have'. At lower fuel states (below 90kgs) you will have both pumps running dry, so iaw procedure they then should both be off, unless you have fuel in the main tank. So 2 Fuel Pump cautions is a picture which might have become 'ok to have' on a 135 if you regularly conduct landings to for instance 60 kgs, which was a previous Day FRF prior to this accident.
If pilots are leaving the dry running pumps then are using work arounds.
Lastly, I think the system is straight forward with a great catch all FUEL caution and Supply Tanks displays - IF THEY ARE WORKING PROPERLY. In my opinion I believe that GSPAO had the same fault as GNWEM.
Last edited by 8Pieced; 11th Nov 2015 at 12:02. Reason: Clarification