[C-FAH Q]

More and more, I read about engines turning fixed pitched props at very high( in my eyes ) rpm's. Is this normal/ok to do this with a fixed pitched?

I have a constant speed on my IO-360-a1b6 and have it limited to 2700rpm.

I came across this Lycoming Mandatory service bulliten that discusses overspeed's, but does not differentiate between fixed and constant speed. It is a interesting and informative read. I had no idea how high some engines are rated for.

http://www.lycoming.textron.com/support/publications/service-bulletins/pdfs/SB369J.pdf

 

[sandifer]

It's "normal" for many pilots of fixed-pitch aerobatic types (Pitts, One Design, etc.) to briefly see 3000+ rpm on a downline in order to gain sufficient airspeed for certain maneuvers without giving up too much altitude. This has been done for decades. Whether or not it's "OK" depends on your definition and how you think about these things. Never a bad idea to adhere to the mfg's recommendations. In my anecdotal and personal experience, I'm not aware of any problems directly attributable to this aspect of engine operation. There are many ways to shorten the life of an engine. The biggest one is running it too infrequently. Most serious aerobatic pilots don't expect to make TBO anyway, regardless of RPM considerations. Exceeding redline just goes with the territory for some. It's hard to know if and how much this is actually accelerating engine wear. Aside from racing or getting max. aerobatic performance, not sure why anyone would need or want to exceed the given RPM limit. It's all a continuum...from a carefully and regularly operated engine doing nothing but x-country cruising, to Reno racing - and everything in between.

 

[Ron Lee]

More and more, I read about engines turning fixed pitched props at very high( in my eyes ) rpm's. Is this normal/ok to do this with a fixed pitched?

Since I am somewhat cautious in this regard I just do not do it. I have no operational need to do so anyway.