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-   -   Start Up Engine Overspeeds (https://www.pprune.org/rotorheads/190402-start-up-engine-overspeeds.html)

chalmondleigh 17th Sep 2005 07:27

Start Up Engine Overspeeds
 
Last year a hirer of my R44 started it with the throttle open (don't know how far) and trashed the engine.
Several people have suggested to me that starting the engine with the governor on would stop this.
My own feeling is that the governor would not be able to react fast enough to contain the unrestrained acceleration you get when starting with the throttle open.
Does anyone have any information on this and have you been brave enough to try it?

bellfest 17th Sep 2005 09:18

The governer on will make no difference. It will still rev way above what it is supposed to. Overspeeding without any load is the worst kind. I would suggest starting it every time with the governer off and your brain on and your pushrods will love you forever.

The Nr Fairy 17th Sep 2005 13:11

Make sure everyone who flies your aircraft is taught to do the following, just prior to start:
  • Throttle closed
  • Igniters on / Mixture rich (depending on type)
  • Rotor Brake off
  • Blades athwartships / tiedowns off (type dependent again)

The menmonic BITT (Brake, Igniters, Throttle/Tiedowns) may also be of use.

Takes 15 seconds but saves a lot of grief.

helicopter-redeye 17th Sep 2005 15:55

Add an E to the end of the mnemonic for:-

EYEBALL moves down and physically checks that the throttle is CLOSED before doing anything else.



Actually the worst overspeed is lifting into the hover without the engine govenor on because it does more damage to more parts. Engine overspeed + spindle damage (far more expensive ...)


h-r:)

Hangar3 17th Sep 2005 17:03

I was always taught that the last thing you do before turning the key was to have your left hand firmly closing throttle, right hand to turn the key.

Doesn't Robinson now require start up check list:
Gov............ON

Although I agree, I doubt it would stop an overspeed if the throttle was left open.

ThomasTheTankEngine 17th Sep 2005 21:50

Robinson check list's do have the governor turned on for engine start up now (I has been so for about 8 months or so)

If the governor is off it will not protect against an overspeed, however if the governor is on there is a chance it could protect against an overspeed it depends how much the throttle is open.

Did the person pay for the damage he caused or did you have insurance against overspeed's etc?

Pear 20th Sep 2005 10:38

I agrre that the governor wouldn't catch an overspeed, but it might bring it back down before a sleeping pilot.

What I'm concerned about also is the governor taking it to 100 in the case of just hitting 80 or more. That could shock a student into doing something odd.

Just make sure it's pushed right against the spring. At least there's no idle button to catch you out.


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