![]() |
Weight difference: alum vs comp props
Planning on using the Hartzell blended airfoil 74" aluminum prop on my -14. However, I would like to consider a composite prop but want to make sure that I don't create a CG problem. Where can can I find the weights of the aluminum Hartzell and the Whirlwind and Hartzell composite props? I'm planning on moving the ELT to just behind the aft baggage bulkhead but not sure how much more I'd have to move (or what) to maintain the same CG. I seriously doubt the ELT move will come close to matching the CG shift caused by the prop change.
|
I think the aluminum Hartzell vs the Whirlwind is something like 55 vs 42 lbs. I know there are a few 14s out there already flying with the composite Hartzell and Whirlwind props.
|
Props
We love our Hartzell composite prop, and I have flown many other ones before we decided on it. It is very smooth, the climb is fantastic and the CG could not have worked out any better if we planned it. The spinner that you need for it is beautiful, long and sleek. The only downside I can think of is the cost. You get what you pay for. Buy it, you will be pleased. Good Luck
|
Prop weights
Ray,
I have been exchanging e-mails with Matt Van Voorhis at Hartzell about prop weights. Here is some info I received recently from him in an e-mail: "The most common 2 blade blended airfoil prop is the F7497 blade model. That propeller weighs about 58 pounds. The most common Van's composite propeller would be either the N7605 blade or the NC8301 blade. Those propellers weigh 43 and 41 pounds respectively." Matt's e-mail is: mvanvoorhis@hartzellprop.com |
Carl, Oly, thanks for the information. Very useful in my planning.
Carl, you mentioned the spinner. I found it curious that the second-hand QB kit that I bought included a spinner but I didn't ask about it. I would have presumed that would have come with the firewall forward kit. I only have empennage, wings and tail. Did you buy your spinner from Hartzell? |
Quote:
It they mean extended hub like the old Twin Comanche, that would be a deal breaker for me. If it is the hub that works on Van's standard cowl, then that works for me. |
Carl, on your great website you have your w&b posted prior to paint. Any chance you can update us on what you paint job has done to the cg and weight of your plane?
Thanks |
Quote:
|
Quote:
I did email Matt to ask about the extended hub. Will report back if I learn anything. It appears that the hub listed on Van's website has the same Type Certificate Data Sheet. P-920. The confusing part is that C in the hub model: "Identifies basic design ? C denotes no integral shaft extension" on the above linked TCDS. That is why I emailed Matt to learn more. |
I am currently planning to follow Carl and Rafael's lead with the Hartzell composite prop. What is the concern about the extended shaft? Doesn't a Twin Oomanche have O-320 engines?
|
| All times are GMT -6. The time now is 12:15 AM. |