Sid, Tandemrotor's post reads
Now, we have no idea yet what the precise situation was here, and we won't for some time. But if anyone wishes to understand how a police helicopter's fuel system can be mishandled to cause a double engine failure and autorotation, then there is an example from Christmas Day 2001 involving G-DPPH. You can google the AAIB report and see how the AAIB regards TFOs, and how the pilot explained the situation to them.
I see it has been edited. I don't know what it originally said, but the way I read what's there now, is that he is suggesting, either, how Nick explained it to the AAIB or to the TFOs on board.
I do take issue with TR's suggestion that the fuel system, was mishandled on DPPH. The manual was clear, and wrong, insofar as it did not contain, on the same page, a warning about consequences of suggested actions. The fact that it was changed later supports the idea that it should never have been released the way it was. The engineers made a reasonable request for the tank to be near empty, all on board thought they had enough useable fuel to get back to Carmarthen, turns out they had plenty of fuel, just in the wrong place.
A greater lesson from that AAIB report is that the aircraft lost all power, at 400 feet, and they all walked away from it.
All this focus on fuel pumps re the Glasgow crash is just background noise. They didn't crash because they ran out of fuel, that's just (apparently) what stopped the engines.
The pilot estimated that the total flight time would be 30 minutes and with an hourly fuel burn rate for planning purposes of 200 kg, the 190 kg of fuel remaining was adequate. Flight time to the site was 18 minutes and the helicopter departed the site for the hospital with 143 kg remaining arriving 6 minutes later. Having shut down and offloaded the patient, the aircraft lifted off with 115 kg of fuel for the 10 minute flight back to the operating base. Given the caution of increased unusable fuel of 20 kg contained on page 43 of the Emergency Checklist, and the estimated fuel required of 40 kg for the short transit back to base, the pilot considered that adequate fuel was available.
Shortly after departing the hospital, the aircraft encountered a line of heavy snow showers across the track to the operating base. The pilot established that the snow had passed over their destination, which was reported as being in sunshine. He explained to the two passengers that 96 kg of fuel remained which he calculated was enough for 30 minutes of flight at reduced power. Their base at that point was about four minutes flight away at the normal cruise speed of 130 KIAS. The pilot informed his passengers that he intended to fly through the band of snow provided that adequate visibility could be maintained.
He descended the aircraft to a height of 400 feet agl and reduced the airspeed to 80 KIAS in order to retain good visual contact with his main reference feature, which was a dual carriageway. After the aircraft entered the snow shower, the FUEL PUMP 2 caption on the EDU began to flicker and then remained on. The pilot considered that the No 2 fuel booster pump had also failed and informed the passengers that they would continue the short distance to the operating base. He explained that the engine driven pumps had sufficient suction to draw fuel from the tanks and thereby maintain an adequate fuel supply to the engines. A few seconds later both engines ran down and the rotor RPM decayed. The pilot realised he had suffered a double engine failure and lowered the collective pitch lever in order to try and restore the rotor RPM. He warned the passengers that they would make an emergency landing and saw a clear field ahead, selected the landing gear down and started to transmit a MAYDAY distress call. Near the ground he flared the aircraft and raised the collective pitch lever in order to cushion the touchdown but this appeared to have little effect. The aircraft landed heavily with low forward speed but with a high rate of descent. It remained upright, the tail boom having detached and the main and tail rotor blades suffered major damage.
The pilot had transmitted a brief MAYDAY distress call which was received by London Flight Information Service who notified the Aeronautical Rescue Co-ordination Centre (ARCC). The Air Observer in the aft cabin seated at the operators console also transmitted on the operational radio frequency that the aircraft was going down at Cross Hands. That message was received by the control room operator, who activated the Emergency Services response to that location. After landing, all three occupants vacated the helicopter through the normal exits and the pilot contacted the control room by mobile telephone to inform them that they were safe. The emergency services arrived at the scene 12 minutes after the accident.