cruise vs. standard prop

[wealscmw]

I was wondering if anyone would know the speed difference between a standard and a cruise prop on a 1966 C-172.

[LR2205]

Both these types of propellers are fixed-pitch propellers.

The difference is that a cruise propeller is going to have a higher blade angle. The engine is going to have to work harder if you use a cruise propeller, because the blade takes bigger bites of air. The advantage of this is that you can achieve a higher airspeed, or cruise speed, once at the desired altitude. The disadvantage is that when climbing altitude, the prop's performance is not going to be as good, and as I said, the engine has to work harder to make the plane climb. When using a climb propeller, or a "standard" as you called it, the plane may not cruise as fast but it's untimately less stress on the engine. I'm not sure what most planes have these days, but my guess would be a standard.

I guess the right type of prop would depend on what you are using the plane for. If it is a trainer plane, get a standard, because trainer planes put a lot of stress on the engine. If you are using it for personal transportation, and need speed, go with a cruise prop.

[Dantilla]

Good explanation.

Think of a car's 5-speed manual tramsmission, and think of a fixed-pitch prop as being that tranny stuck in one gear.

A Climb prop is like staying in a lower gear- Quick acceleration, great climb, but a bit short on top speed.

The Cruise prop is stuck in a higher gear- Lethargic acceleration, but once finally at cruise altitude, better top speed at lower RPMs.

If you are based at an airport at low elevation and a long runway, and make long cross-country flights, go for a cruise prop.

If you fly out of a short mountain strip, you need a climb prop.