skywagon8a
MEMBER
SE Mass MA6
This is from the http://www.supercub.org/forum/showthread.php?50672-Best-STC-for-0320-Conversion thread. I suggest that you get in touch with Ben K. (Fat Kid) since he is closer to you than me and likely uses the same FSDO.Interesting and thank you for the obs. This is over my job class but I have seen CAR 4 5/1938, Par. 04-61 discussed versus TCDS A-696 Item 1. I suspect those involved weren't as familiar as you with the implications. I know I wasn't as a reader. But that is an excellent point...the question is which Reg pertains? Maybe that has already been answered and any further enlightenment would be appreciated.
PROPELLERS§
4a.597 Propellers. Propellers shall be of a type and design which has been certificated as airworthy in accordance with the requirements of Part 14 of this sub chapter or shall have been approved as airworthy in accordance with previous regulations, except that wood propellers of a conventional type for use in light airplanes need not be certificated. In certain cases maximum engine bore limitations are also assigned to propellers. Propellers may be used on any engine provided that the certified power ratings,speed ratings, and bore of the engine are not in excess of the limitations of the propeller as certificated, and further provided that the vibration characteristics of the combination are satisfactory to the Administrator.
The Catto is a wood prop. Install it and all that is required is a Log Book entry.
Ben K.
I did a similar comparison test with EDO 3500s and Wipline 3730s. The Wip would not get on the step yet the EDOs flew away, both with the same heavy load.As far as PK vs EDO, my intent isn't to imply the PK's aren't without merit in conditions like in the rough marine environment, but...in June 1980 I had the opportunity to fly two similarly equipped C-185's on the job for test purposes. Typical hot and calm Fairbanks day in the low '80's. Both planes were IO-520's with long two blade props that turned tach redline and had similar WFO T/O manifold pressures (logged the info). All-up weight was similar ~60 gallons and one soul. The one with PK 3500's (new in 1979 and latest model as of that date) I'd flown more the previous season than the newer one to me on EDO 3430's. No comparison at partial throttle/high D/A takeoff...the EDO's performed better under those conditions for T/O, and displayed a lesser tendency to pitch nose down on landing on glassy water. The PK's would go about 55 mph max indicated on the water (partial throttle with no flaps); the EDO's accelerated beyond that indicated airspeed if kept on the water. No GPS in those days so the speed may be relative. All history now of course.
GAP