PPRuNe Forums - View Single Post - Police helicopter crashes onto Glasgow pub: final AAIB report
Old 31st Oct 2015, 12:11
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SilsoeSid

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I have read through all the posts and I can't find any mention of when it is necessary to turn the Prime Pumps on.
Probably because it was mentioned early on in the original thread.

Basically, with the fuel starvation, the engines would have started to suck air, and you get FUEL PRESS caution on CAD. The actions for this is to turn the PRIME PUMP(s) ON. This would explain the position of the switches, if that is how they were before impact.
Possibly, however imho the Eng Fail caution would trump the Fuel Press caution. Don't forget that even the Fuel caution cannot be confirmed as having been displayed, so any possible caution that should have illuminated may not have.

Another point raised by a colleague; once your electrical power is only being powered by the battery (following a double engine/generator failure), you constantly get a red BAT DISCH warning and audible gong appearing.
This is the same audio gong and another red warning in close proximity to the ROTOR RPM warning, which he probably also would have had in auto.
You'll continue to see the Bat Disch Warning, but the audible warning is cancelable.
The only Nr Warnings were for low Nr, which is a tone and not a gong.
The Batt Disch did not come on until the fourth Low Nr Warning was activated. (P.33)

Nr Low - <97% ---Steady light & intermittent low tone (800 Hz)
Nr High ->106% - Flashing light & warning gong
Nr High =>112% - Flashing light & continuous high tone (2400 Hz)


- forgetting in the heat of the moment that NR is your friend and it doesn't matter(to a point) if it gets too high) - where as the audio gong is for the BAT DISCH, and you cannot hear the Intermittent Low tone for LOW NR.
Forgetting you need Nr, really!!!
You can also hear the actually sound of the gearbox/Nr dropping Or rising itself.
Again, the Batt Disch did not come on until the fourth Low Nr Warning was activated. (P.33)



And it's proven that in high workload, it is your hearing that goes first. But as has been said, without a CVR/FDR....
I thought you just told us the sound of the gong was off putting to anything else that might have been going on

Last edited by SilsoeSid; 31st Oct 2015 at 13:16. Reason: Reference to report page number for Warnings sequence.
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