It's been a very long time away from the Puma for me but I do remember that an electrical system mod was carried out after the fatal Salamanca accident.
The alternators used to drop off line after two seconds at a reduced, but relatively high rotor RPM. The mod was to leave them on line until a droop to a lower rotor RPM occurred. I can't recall the RRPM figures after nearly fourteen years.... (The significance of the alternators dropping off-line was that the single channel autopilot came off-line and so there was suddenly no attitiude stabilisation).
Edit:
A few rusty old cogs have turned. I now recall that the normal governed band for the Puma's Nr was 265 +/-7 and I think that the alternators were initially rigged to drop off line after 2 seconds at 240 Nr. If my old brain has dusted off the correct file, they were subsequently modified to stay on line until 220 Nr, after which they would drop off line as before. The logic was that it was sometimes impossible to regain the Nr above 240 within 2 seconds after a single engine failure at low speed; 220 Nr was more sustainable.
The Salamanca accident was horrendous, I'm very glad to hear that these two 412 pilots are OK.
Last edited by ShyTorque; 9th September 2007 at 12:49.