Startup With Stop Rotor

[C-FXFX]

Just wonder if we can startup s-76 with the rotor stopped,why we can not be able to do the same with a Jranger a L or 222 or a 412?

 

Humm can't remember why!

 

GUY

[Reddog]

Probably because your engineeroid isn't strong enough to hold the blades with an engine at idle.

[Dan]

That's a good question. I would like to hear a good answer too.

I've seen a 212 started with the rotor brake on when the winds were strong and gusting. The brake was released about half way thru the start to help reduce blade sailing. It seemed to work. I know it's not a normal procedure but it may be done in the field I'm quessing. Maybe a question to send to Bell.

[212wrench]

I have held a 212 in a strong wind during start and at about 25% it gets real hard to hold onto.

[ZAPPER68]

Starting up with the rotors stopped......now there is a novel idea. I've been doing that exact procedure for over 35 years and it works every time, at least on the Bell 47, Bell 206, Bell 212, Bell 412, MD500, R22, A109S, EC130B4 & AW139.

 

I'm not too sure about other helicopters but I believe you can start them with the rotors stopped also.

 

ZAP ZAP

[C-FXFX]

Starting up with the rotors stopped......now there is a novel idea. I've been doing that exact procedure for over 35 years and it works every time, at least on the Bell 47, Bell 206, Bell 212, Bell 412, MD500, R22, A109S, EC130B4 & AW139.

 

I'm not too sure about other helicopters but I believe you can start them with the rotors stopped also.

 

ZAP ZAP

Ok!so how do you do that with a 47!

 

Oh! and by the way i know that is not a new idea...!!

[Jay Flight]

I'm a new guy but I think he was getting at that aren't all rotors at rest when you go to start them or does your ground crew start the blades by hand before the start switch is hit?

[Max Continuous]

Yeah I think you get it! :lol: :lol:

[Spitzair]

One explanation I got, and I could be very wrong here, is that on larger multi-bladed helicopters the mast sits on an angle and the dampers slowly let the blades creep to wherever gravity takes them, so one blade or more will be in a lead position and another one or two is in a lag position and if you start 'er up slowly you have a significant out of balance condition whereas if you hold the binders on till your stove gets up to speed the inertia of the blades at rest cause 'em all to go to a full lag position on the dampers when the mast starts to turn when you let the brake go... Once she's up to proper RPM which now only takes a few seconds, the blades find their happy place and away we go! Clear as mud? Anyway, that's what I've been told so I have no idea how true it is though it does make sense to me.

[Elvis]

On the S61 the #2 engine is started before releasing the rotor brake so the hydraulic power is available.