I have tried to contact Hartzell about this, but no word since.

Can anyone explain how to make sense of Hartzell P/N's. I get some of it, like the number of blades, the hub/blade, length, and the R or L rotation, but how can I tell if it's a climb or cruise prop etc?

E.g.
Hub / 84" Blade: HC-C2YR-1RF / F8475R

Hi,

Try the TCDS P 920

http://www.airweb.faa.gov/Regulatory_an ... /P-920.pdf


Cheers

Battson wrote:I have tried to contact Hartzell about this, but no word since.

Can anyone explain how to make sense of Hartzell P/N's. I get some of it, like the number of blades, the hub/blade, length, and the R or L rotation, but how can I tell if it's a climb or cruise prop etc?

E.g.
Hub / 84" Blade: HC-C2YR-1RF / F8475R

The 8475 spells out the prop diameter (84) and blade pitch (75).

Think of the pitch as the distance forward the prop would move in one rotation if it were rotating in a bowl of jello, or if it were a screw, being driven into some media. So a 75 pitch is more of a "cruise " prop than say a 44 pitch would be. This is all effective pitch, since this is a constant speed prop and the blades will change pitch in flight.

If the designation were followed by a "dash number", ie: 8475-4, the dash number implies that in this case, four inches have been cut off the base prop, reducing the diameter, usually for a different application. These props are often used on numerous aircraft, with different diameters as appropriate.

MTV

Brilliant - thank you very much.

Now if I only knew what a "climb" pitch prop should be for a Bearhawk

If you're looking at constant speed props, like the one you listed, there's really no such thing as a "climb" prop. And, in fact, having had my fill of Hartzell ADs I'd give the guys at Flight Resource a call, and visit with them about MT props.

Or, there are a number of non certified props out there that can be used on an EX.

If you're thinking fixed pitch, what engine are you using?

MTV

I guess I assumed they'd use a different aerofoil depending on the airspeed you wanted best performance at. Guess not.

We will go MT soon, but can't afford in right off the bat, unless it's at second hand prices (cept nobody sells 'em)

It will be constant speed, but for what it's worth, it's an IO-540.

Then call Hartzell or look at their web site or both,and ask what props have been vibration tested on your engine, and what prop should work best on your type airplane.

MTV