Police helicopter crashes onto Glasgow pub
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“Both the Chief Constable and Chief Superintendent Ian Whitehouse, the accountable manager of NPAS, have assured the board that all relevant risks have been identified at this stage and all appropriate operational measures have been taken.”
Purveyor of Egg Liqueur to Lucifer
In light of the Ch Supt's statement, why does he think it safe to allow his ac to continue flying when Bond have grounded all their aircraft?
"Safety is the number one priority for the National Police Air Service (NPAS). Our decision on whether or not to suspend operations or ground any NPAS aircraft is based on advice issued by the Civil Aviation Authority".
How is it that Bond, with the same advice from the CAA have a different look on this? If the extra 100kgs is a safe way of continuing operations, why haven't Bond opted for it?
Wouldn't it be strange if an NPAS EC135 went into a Bond Police base for a refuel while on task in the Bond aircrafts area!
I have the feeling that in the months and years to come, that we will be talking about this on CRM courses around the country, the whys and wherefores, commercial pressures and ultimately, why does a commercial company take one course of action while a public service provider takes another?
"Safety is the number one priority for the National Police Air Service (NPAS). Our decision on whether or not to suspend operations or ground any NPAS aircraft is based on advice issued by the Civil Aviation Authority".
How is it that Bond, with the same advice from the CAA have a different look on this? If the extra 100kgs is a safe way of continuing operations, why haven't Bond opted for it?
Wouldn't it be strange if an NPAS EC135 went into a Bond Police base for a refuel while on task in the Bond aircrafts area!
I have the feeling that in the months and years to come, that we will be talking about this on CRM courses around the country, the whys and wherefores, commercial pressures and ultimately, why does a commercial company take one course of action while a public service provider takes another?
2 questions for EC-135 experts:
If a main fuel tank transfer pump check valve failed, is it possible that the resultant rate of transfer into the supply tanks could be below the dual engine fuel burn rate?
What would the consequence be if a pump with check valve was installed in a supply tank?
If a main fuel tank transfer pump check valve failed, is it possible that the resultant rate of transfer into the supply tanks could be below the dual engine fuel burn rate?
What would the consequence be if a pump with check valve was installed in a supply tank?
I have the feeling that in the months and years to come, that we will be talking about this on CRM courses around the country, the whys and wherefores, commercial pressures and ultimately, why does a commercial company take one course of action while a public service provider takes another?
And there are no real differencies in the height of pressure beween public and private or commercial operators. May be the kind of pressure is different.
Imagine the extreme results of an EC 135 grounding worldwide and compare it with the discussions about a grounding of uncle Frank toys after countless accidents.
Uncompromising safety culture is a myth.
JimEli - sorry, you seem to have been ignored
2 questions for EC-135 experts:
If a main fuel tank transfer pump check valve failed, is it possible that the resultant rate of transfer into the supply tanks could be below the dual engine fuel burn rate?
At Max continuous power, possibly yes - although, with the line blocked there would still be a "Tx Pump" caption displayed to the pilot.
What would the consequence be if a pump with check valve was installed in a supply tank?
The pumps in the Supply Tanks are the prime pumps and are only on for the start until the engine driven pumps have sufficient "Suck". If the wrong pump had been installed and the check valve had stuck shut then the engine would not start. Once it is running, it would be difficult for the valve to close against the flow of fuel but, if it did so then the engine would stop.
Hope that is of some use.
2 questions for EC-135 experts:
If a main fuel tank transfer pump check valve failed, is it possible that the resultant rate of transfer into the supply tanks could be below the dual engine fuel burn rate?
At Max continuous power, possibly yes - although, with the line blocked there would still be a "Tx Pump" caption displayed to the pilot.
What would the consequence be if a pump with check valve was installed in a supply tank?
The pumps in the Supply Tanks are the prime pumps and are only on for the start until the engine driven pumps have sufficient "Suck". If the wrong pump had been installed and the check valve had stuck shut then the engine would not start. Once it is running, it would be difficult for the valve to close against the flow of fuel but, if it did so then the engine would stop.
Hope that is of some use.
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How does a UK trained pilot end up with rotors not turning
I wonder how many twin pilots ever carry out an auto to the ground as opposed to a powered recovery to the hover? OK, I'm a bit out of date, but I never did on twins. I never heard of tins being autorotated to the ground - it was just never done. Has this changed? And in light twins there are no/few simulators so it is just not something anyone ever gets to do.
Double engine failure was something that was just not anticipated - or trained for except in theory. If you never flew a single you simply never practiced it; you only got one failure at a time. Perhaps this is an out of date observation? Perhaps not?
DAPT: What's your problem - why are you continuously asking the same Q? If we knew the answer to how the rotors stopped, we'd be front page news and the AAIB would pack up and go home.
Avoid imitations
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Might I suggest that many of our most experienced and best trained twin engine pilots may well be quite unpracticed in sudden double engine failure and autorotation?
Ag Bis,
Can confirm what you say. Have only done full down auto's on the 135 in the sim. All OPC auto's are to flare recovery - again, if you are briefed & expecting them in the training scenario it's very different from the sudden real event. Single engine failures/rejects etc practised by the bucket load. When I was Twin Squirrel rated I did get to do an EOL on a single but that's 11 years ago now.
Can confirm what you say. Have only done full down auto's on the 135 in the sim. All OPC auto's are to flare recovery - again, if you are briefed & expecting them in the training scenario it's very different from the sudden real event. Single engine failures/rejects etc practised by the bucket load. When I was Twin Squirrel rated I did get to do an EOL on a single but that's 11 years ago now.
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Answer for DAPT
DAPT asks: "How does a UK trained pilot end up with rotors not turning ?"
In forward flight:
1. Fenestron fail.
2. Turn down engine power.
3. Fail to move cyclic in direction opposed to airflow.
4. Airflow stops rotor.
Note - In order to see this you need to think outside the box. Imagine a model helicopter in powered forward flight and see the airflow vectors. Then see it morph into an autogyro with same c of g velocity but totally different attitude and airflow vectors. Without the attitude change the airflow stops the rotor.
Not a pilot, just a dull old engineer, never seen this problem before.
In forward flight:
1. Fenestron fail.
2. Turn down engine power.
3. Fail to move cyclic in direction opposed to airflow.
4. Airflow stops rotor.
Note - In order to see this you need to think outside the box. Imagine a model helicopter in powered forward flight and see the airflow vectors. Then see it morph into an autogyro with same c of g velocity but totally different attitude and airflow vectors. Without the attitude change the airflow stops the rotor.
Not a pilot, just a dull old engineer, never seen this problem before.
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We don't do the check to the ground because it's a 6 million dollar corporate aircraft.
We did all these tricks in the 206 but not in twins because they were deemed "too costly" to risk bending, plus the assumption that a simultaneous total power failure in a twin just wouldn't happen.
I don't recall ever doing total power failure in the high hover in a twin, but maybe senility has intervened. It was trick enough in a 206 even when expecting it. In a 355 (my ship) - for real? - I wouldn't want to have been there.
It ay be that this event has highlighted a chink in our armour. I daresay this accident will lead to one certain result - mandatory CVRs and/or data recorders. I hope it doesn't get as far as mandatory two pilots but I'm not holding my breath.
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being under stress, switching off the wrong engine has happened in fixed wing aircraft.
then the pilot has more stress, perhaps his brain gets shock frozen in for some seconds - and he is finally doomed when flying a heli at low alt missing his entry for autorotation? or reserve fuel miscalculation. Hapag Lloyd Airbus gliding into Vienna some years ago was a 'good' example that it is sometimes the very experienced pilot who does the big mistake and then doesn't even correct it, despite P2 insisting . quite right, 2 pilots do not make sense ...
then the pilot has more stress, perhaps his brain gets shock frozen in for some seconds - and he is finally doomed when flying a heli at low alt missing his entry for autorotation? or reserve fuel miscalculation. Hapag Lloyd Airbus gliding into Vienna some years ago was a 'good' example that it is sometimes the very experienced pilot who does the big mistake and then doesn't even correct it, despite P2 insisting . quite right, 2 pilots do not make sense ...
Last edited by xlsky; 12th Dec 2013 at 22:54.
I asked this a few pages back but didn't get an answer - what would happen if in a critical situation, already too low and with no engine power, the pilot had to clear a tall building directly in front of him?
I looked at the crash site again today from a distance, and if the witness at Glasgow Cross who saw the helicopter flying unusually low and apparently only just above the Osborne St railway viaduct (accepting that this may have been a line-of-sight error with it further away and slightly higher, but even if this is true) is correct, it would have only just cleared the glass-roofed building immediately to the east of the Clutha. This building looks to be about 35 feet high.
Could trying to gain even a tiny bit of height to clear the top of this building cause a rotor stall? If so, would the impact point be about the same distance beyond the building, give or take a bit?
I looked at the crash site again today from a distance, and if the witness at Glasgow Cross who saw the helicopter flying unusually low and apparently only just above the Osborne St railway viaduct (accepting that this may have been a line-of-sight error with it further away and slightly higher, but even if this is true) is correct, it would have only just cleared the glass-roofed building immediately to the east of the Clutha. This building looks to be about 35 feet high.
Could trying to gain even a tiny bit of height to clear the top of this building cause a rotor stall? If so, would the impact point be about the same distance beyond the building, give or take a bit?
DAPT asks: "How does a UK trained pilot end up with rotors not turning ?"
I have to ask what relevance being "UK Trained" has to do with that eventuality?
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DAPT,
Why don't you just come out with what you're really thinking. I don't want to speak for the majority of the forum but it would be fair to say there are many scratching their collective heads as to this stopped rotor theory. If you could enlighten us with your thoughts of why we have a relatively intact airframe and stopped rotors. Even the very experienced pilots on here can't come up with a highly likely reason. For now play the ball not the man until something to suggest otherwise comes up!
Regards
MF26
Why don't you just come out with what you're really thinking. I don't want to speak for the majority of the forum but it would be fair to say there are many scratching their collective heads as to this stopped rotor theory. If you could enlighten us with your thoughts of why we have a relatively intact airframe and stopped rotors. Even the very experienced pilots on here can't come up with a highly likely reason. For now play the ball not the man until something to suggest otherwise comes up!
Regards
MF26
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DAPT,
I explained why there is no Nr on my post on page 57. I emphasise again that this is not such a mystery in accident investigation, as it has happened in other helicopter accidents in the past.
I explained why there is no Nr on my post on page 57. I emphasise again that this is not such a mystery in accident investigation, as it has happened in other helicopter accidents in the past.
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Rotor not turning
Maybe the Nr decayed to the point it was matched to the strobing of the HISL our brains are easily confused into see something that is not quite right
WDU
WDU
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SAS - "UK Trained" are you not reading the Autorotation thread?? Clearly we in UK all knew about the "Best kept Secret" and you yanks did not!!
Shame nobody told the 8 candidate instructors I have had under training this year, all who failed to apply aft cyclic to enter auto, crashing the SIM in the process.
There are none so blind as those that cannot see!!
Peter Gillies is 100% correct. By the time the pilot reacts the NR is already seriously decayed. The only way to get it back is to flare, meaning pull the cyclic back.
SAS remember, we Brits are better than everyone else and if we have accidents we will blame anything and everything.....except ourselves. Pilot error......that's what Johnny Foreigner does!!
Shame nobody told the 8 candidate instructors I have had under training this year, all who failed to apply aft cyclic to enter auto, crashing the SIM in the process.
There are none so blind as those that cannot see!!
Peter Gillies is 100% correct. By the time the pilot reacts the NR is already seriously decayed. The only way to get it back is to flare, meaning pull the cyclic back.
SAS remember, we Brits are better than everyone else and if we have accidents we will blame anything and everything.....except ourselves. Pilot error......that's what Johnny Foreigner does!!
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DB is 100% correct. Us Brits have this stuffy elitism about us to think we are a cut above the rest. Peter is right and Mr Dick Sandford wrote a very interesting article to suggest that in the UK we are not getting it right. With that said there is nothing to suggest thus far that Dave done anything wrong. Time will tell.
Regards
MF26
Regards
MF26