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From: Lorn H. Olsen <lorn@dynacomm.ws>
Subject: Re: Constant speed props

Terrence,

Below is a letter that I posted to the Lancair mailing list 2 years  
ago to the day. The only thing that has changed is that I now have  
about 600 hours on the prop.

I had an engine overspeed more than a year ago that was caused by a  
crank plug coming loose. The Aero Composites prop had no problems  
with the overspeed. Many other props would have had to be sent off  
for inspection.

Lorn

> On Apr 6, 2005, at 9:53 PM, mquinns@aol.com wrote:
>
>> Lorn,
>>    I am considering props for my 360 and was told you have an  
>> Aerocomposites prop on your 320 (360?).
>
> Yes.
>
>> Could you tell me if your aircraft uses the long engine mount or  
>> short?
>
> Short.
>
>> Does the prop spinner require modifications to the cowl?
>
> No.
>
>> Is the prop 68 inch diameter?
>
> According to Hartzell at
>
>      http://www.hartzellpropellers.com/kitplane/index_kitplane.htm
>
> you can see that the Lancair 320 is supposed to use the 70" prop.  
> When I first talked to Aero Composites they asked me what diameter  
> I wanted the prop to be. Apparently they had the ability to vary  
> the diameter somewhat. We both agreed that 70" (the same size as  
> the Hartzell) would be best. I got the impression, while talking to  
> them, that a larger diameter is better, as long as the ground  
> clearance is satisfactory.
>
> Hartzell's sight for the 360 lists both 68" and 72" for the 180 hp  
> and only a 72" for the 200 hp 360s. Take a look at the Aero  
> Composites site at:
>
>      http://www.aerocomposites.com/index.cfm? 
> fuseaction=home.viewPage&page_id=E36FDA21-5004-D739-A5792799EC7B5445
>
> for the model that is right for your plane and engine combination.  
> With the Aero Composites prop and the 360 engine you can go with  
> either 2 or 3 blades.
>
> To not leave anyone out, there is also the Whirlwind Airboat  
> Propeller Co. Whirlwind is starting to make aircraft propellers.  
> They cost less and only weigh 28 lbs. I saw one at the KOBZ airport  
> in Georgia. A current problem with their constant speed prop is  
> that it has to go back to the factory every 250 hours for  
> inspection. They should be better in the future.
>
>      http://www.whirlwindaviation.com/
>
>> Do you have any advice after making the choice to go with this prop?
>
> It is a great prop. I now have about 300 hours on the prop and my  
> leading edge looks like new. It doesn't have one scratch on it. The  
> nickel leading edge really works.
>
>> Were there any weight and balance issues caused by lower weight of  
>> the prop?
>
> Originally my planes CG was to far aft. The lighter prop didn't  
> help at all. I have solved the CG problem using 3 different  
> techniques.
>
> 1) I have a "Harmonic Dampener" that weighs 12 lbs attached to my  
> flywheel. This doesn't hurt at all. Scott Krueger also has one.  
> Besides adding weight to the front of the plane, the dampener  
> smoothes the engine. This additional weight moves the CG forward  
> 1/2". If you are interested, they are made by:
>
>      Mark Landoll
>      1205 Red bud Lane
>      Newcastle, OK 73065
>
>      405-392-3847
>
> I paid $387 for mine a couple of years ago.
>
> 2) I had my battery moved from behind the baggage compartment to  
> behind the passenger seat.
>
> 3) I carry about 20 lbs of tools in front of the passengers feet.
>
> My current CG is 58.6" behind the aft end of the propeller spinner.
> This converts to 24.1" using the forward face of the firewall.
> I am still pretty far aft.
>
>> Thanks for your help.
>>
>> MARK QUINN
>
> In summary, the Aero Composites prop is the best prop that I have  
> ever flown behind. I believe that it has increased my top speed by  
> about 5 knots. In the Redmond 2004 100 mile race, I came in first  
> in the 320 class. In the Sun 'N Fun 2004 100 mile race, I came in  
> second in the 320 class. To bad it was cancelled this year.
>
> Good luck with your decision and feel free to call if there are any  
> other questions or problems.
>
> Sincerely,
> Lorn
> --
> Lorn H. 'Feathers' Olsen, MAA, DynaComm, Corp.
> 248-345-0500, mailto:lorn@dynacomm.ws
> LNC2, O-320-D1F, 1,000 hrs, N31161, Y47, SE Michigan

--
Lorn H. 'Feathers' Olsen, MAA, DynaComm, Corp.
248-345-0500, mailto:lorn@dynacomm.ws
LNC2, FB90/92, O-320-D1F, 1,300 hrs, N31161, Y47, SE Michigan