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Rotor Rpm Vs Vne


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Winnie, modern helicopters (like 407 Driver's red-rocket) , are fitted with a FADEC system that sets the RPM to 100% and keeps it there, using digital, multi-phase, recirculating, discombobulating thinga-mejigs.

Older technology machines need a bit of help to keep the RPM at the preferred setting because the governors are sometimes a little slow (or getting tired).

Therefore the pilot uses the beep switch to keep the RPM where it is supposed to be, (unless the pilot is getting a little slow or tired, in which case he just tries to keep it somewhere between where the horns come on !!!

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Winnie, are you sure that he was only "Starting" it? That FADEC system has a lot of protection against such an event ever happening?

One of our big problems is starting at High Altitude -High OAT- High Residual MGT (Measured Gas Temperature), then throw in a downwind component, and you're not going to get a start...... It will shut down the start if the MGT even gets near start limits or if it deems the start acceleration may get near limits.

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I love how this forum wanders off topic.........


Winnie, they only time I heard of a 407 cooking it's engine on start-up was because the pilot started it in MANUAL mode, not AUTO. Therefore there was no FADEC protection for the engine. The FADEC can cover the pilot's butt from many screw-ups, but only if it is turned on !!


This case would be the same as taking a Long-Ranger's throttle to the idle position, and then touching the starter !!!!! ( Houston, we have ignition, AND a problem).


The pilot involved in this situation is well known and respected in this business (just like 407Driver, but it wasn't him), he admitted his error, felt terrible about it, and should remain nameless.


The 407 is a good machine, admittedly it has had a few problems, but this one was not the aircraft's fault.


Now back to the topic........some 407s can be switched down to 90% Rotor speed to provide a quieter noise signature. I have never flown one with this kit. If anyone has...what happens to the VNE limits ???

This would be interesting because, as many of you know, the blades of a 407 spin very fast at 100%, and the machine has a real kick-arse cruise speed and can easily reach its VNE of 140 knots if you lower the nose a little.


(CTD, are you back online yet, do you know?)

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The feller I know who did it was in California, so noone here mentioned. And thanks for the information as well!!



Now for the event,

The Gander Air Show 2003, I shall presently go out and drool over Shark 441, my alltime favourite, the Sea King, and the super kitten from Cougar will be up as well.

See ya :up:

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