Rotor Over Speed

[fraundo]

Hello Everyone:

I am new to this board and also just recently got my private pilot certificate. Like many people I did my training in an R22 because that is what the flight school offered. I bought a Brantly B2B last year before I even finished my training but since I was so far along and my instructor was not able to instruct in the Brantly I finished in the R22.

Now I am flying the Brantly after a few hours of transition training and I am still getting used to managing the throttle without the aid of a governor. As such I sometimes find myself a bit over the noted maximum rotor speed.

I am wondering if anyone has an opinion on how detrimental this is and at what point I should do whatever overspeed checks there are. I am not a mechanic but there is one in my area who attended the Brantly training course in April 2008. I am not sure if that was covered or not. I have to ask him, but I also wanted to hear from others in the Brantly community. I imagine others have had this same problem.

I have already learned quite a bit about flyign the ship and it happens much less often than at first but I do still have to concentrate to ensure I do not go over the max and from time to time it occurs. Generally for only a few seconds before I correct.

Any other tips for me as I learn this ship are apreciated. I have logged about 20 hours so far. I love the ship and am happy with my decision to buy one, I just hope it is robust enough to handle my learning curve.

Best regards all.

[9121u]

HI how much are you going over the red line. I have heard you can go over a little.there is nothing to check for over speed except your main rotor blades. and tail blades. i wouldent make a habbit out of it. talk to you latter.

[fraundo]

Thanks for replying. I am traveling for a couple of weeks and I will have to look at the tachometer when I get back to see at what RPM the redline is and the scale. I do not recall offhand. I tend to just use the green arc. I do not think it is a lot but that is all relative. I just recall that in the R22 when I was training it was a major deal if you ever went over redline and they had to do an overspeed check which took like half a day or something for the mechanic. I never did overspeed in the R22 (mostly only happens when doing autos) but I know a lot of students who did. The check ride guy I checked out with said he fails a lot of students for that. I am hoping it is less of an issue with the Brantly until I get better with not letting it happen. I have improved a lot already but I am still a little on the high side sometimes.

[pahoota]

All aircraft must be designed with a safety margin so transient excursions past these limits are generally acceptable. Most of the big turbine fixed-wing and rotor aircraft will specify the transient times, for example a 12 second Ng transient above 102% RPM in a turbo-shaft engine. I know a lot of the GA aircraft don't specify transient times. In that case, it's best to treat the limits as "do not exceed" to the best of your ability, but minimal excursions of just a few seconds will happen. Any time you exceed aircraft limits note how long you exceeded the limit and by how much, and tell your mechanic. You should be OK though, unless you are hanging out at like 110% Nr for 30 minutes. The danger of high rotor speed in an autorotation is generally not a mechanical one, but an aerodynamics one. High Nr will result in excessive rates of descent, and that's why some examiners will fail pilots on checkrides for carrying too much rotor speed.

I've never flown a Brantly; I wasn't aware it didn't have a governor! Good luck: that's real helicopter flying!

[fraundo]

Hi and thanks for the reply. I am back in town and looked closely at the tach and I would estimate the worst I have ever gone over speed is to 500RPM(redline is 472) and never more than 30 seconds, usually more like 5 seconds and less than 500 before I would notice. I did tell my mechanic about it and he also said it should not be an issue but of course to keep working on avoiding it altogether. Any others with comments please share, particularly if you disagree with this assessment. Also if you have opinions on anything specific to check on the blades when doing an inspection following an over speed or other checks in addition to what has already been posted.

thanks again.