National Aeronca Association Bulletin Board

I noticed that on the ACA site, the LSA Champ (7EC) is now equipped with an O-200 and a WOOD Sensenich W69EK prop. I sent a note to Sensenich asking for guidance on the suitability of this prop to a Chief with the O-200, and they replied that it ought to work great. It is a certificated prop. It's not, of course, listed on the Wagner STC, so field approval would be necessary. Here's a link to the info Sensenich has up: http://www.sensenichprop.com/sen_html/p ... -rev_4.pdf

Anyone tried this yet? And if so, what was the impact of the lighter prop on the weight and balance?

Alan,

If its a wood prop, there are LARGE allowances on the TCDS for these and am guessing (do not have the Champ version open here) that its probably legal.

What they do is put a RPM limit on the prop and as long as the prop does not exceed this then its legal to use on the airplane. Might check it out.

Joe A

From A-759
~~~~
VIII - Model 7EC, 2 PCLM (Normal Category), Approved November 30, 1949
Engine Continental C90-12F or C90-12FJ
Engine Limits For all operations, 2475 r.p.m. (90 hp.)
Propeller Limits Static rpm at maximum permissible throttle setting:
(For fixed pitch Not over 2350, not under 2125. No additional tolerance permitted.
wood propeller) Diameter: not over 72 in., not under 70 in.
~~~~

Propeller and Propeller Accessories
1. Wood Propellers - fixed pitch
Models 7AC, 7BCM, 7CCM, 7DC
Models 7EC,7FC, 7JC
10 lb.
(-52)
(-54)
(a) Sensenich 72C-44 (Models 7AC and S7AC)
Sensenich 72CK (Model 7BCM)
Sensenich 72CK-44, -45, -46 (Models 7DC, S7DC)
Sensenich 72GK-48, -49, -50 (Models 7CCM, 7EC, S7CCM, 7FC, 7JC)
(b) Flottorp 72A50, 52 (Models 7CCM, S7CCM, 7EC, 7FC, 7JC)

(c) Any other approved fixed pitch wood propeller which is eligible for the engine
power and speed and which meets the diameter and static r.p.m. limits specified
under "Propeller Limits" for the pertinent model.

Thanks Joe,

The Sensenich data sheet lists max continuous HP and RPM as 125/2800--perfect for an O-200. ACSpruce lists a W69EK7-63 at about $1200. At this point, it's sure the leading candidate for mine.