Looking for an STC for Putting and Cont. 0200 in a Piper PA-11
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From, what I have seen, from our FSDO, out here in North Carolina, It is Just a Log Book entry, Because, the C90, that Piper installed in the PA-11, in 1948, is on the same TCDS, as the 0-200-A, B, & C, Now there is a PA-11, in TN, with the 0-00-A, his serial Number is 11-435, so I have his Historical records, there is nothing in them. Hope this helps. Old Dude.
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As I recall, and maybe Dave Calkins will remember, the PA-11 had a limitation of no floats on the 100 hp engine; cooling I believe was the issue.
Continental torque and power curves plotted for the C85, C90, and O-200. I note in passing that Continental got the C90 torque data point wrong at 2350 rpm.
Also according to Continental, at sea level when rpm of the O-200 is between 2125 rpm and 2875 rpm, it makes more torque than the peak torque of the C90.
However, if your airstrips are located at more than 9500 MSL, you are better off with the C90. And at sea level, Continental data indicates that the C90 will make more power than the O-200 when the rpm is below 1800.
Also according to Continental, at sea level when rpm of the O-200 is between 2125 rpm and 2875 rpm, it makes more torque than the peak torque of the C90.
However, if your airstrips are located at more than 9500 MSL, you are better off with the C90. And at sea level, Continental data indicates that the C90 will make more power than the O-200 when the rpm is below 1800.
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"As I recall, and maybe Dave Calkins will remember, the PA-11 had a limitation of no floats on the 100 hp engine; cooling I believe was the issue".
What was the source of that data?
The O-200 isn't a log book entry because it was not included in the PA-11 Type Certificate (A-691), and I've never been able to find an STC for installing an O-200 on an 11 (I did find a bogus one that had been faked). I would love to find one because I've got an 11 that needs an engine and an O-200 that needs a plane.
What was the source of that data?
The O-200 isn't a log book entry because it was not included in the PA-11 Type Certificate (A-691), and I've never been able to find an STC for installing an O-200 on an 11 (I did find a bogus one that had been faked). I would love to find one because I've got an 11 that needs an engine and an O-200 that needs a plane.
The McCauley 1B90 7535 is certified on the O-200 as the Cessna 150 seaplane prop.
On an O-200 powered J3 that prop will turn 2850 rpm in a 55mph climbout, so likely a 7538 or maybe even 7540 would be a good climb pitch for an O-200 PA-11.
As an aside, the 1B90 7440 will outpull a 7535 up to about 2850 rpm static pull. At higher static rpm, the 7535 pulls better.
On an O-200 powered J3 that prop will turn 2850 rpm in a 55mph climbout, so likely a 7538 or maybe even 7540 would be a good climb pitch for an O-200 PA-11.
As an aside, the 1B90 7440 will outpull a 7535 up to about 2850 rpm static pull. At higher static rpm, the 7535 pulls better.
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jim you would be perfect to be the source of the data?? as familiar as you are with the 0-200 and the j3s you got my vote.
dgapilot says he thinks it would be easy to do an STC for the installation, and I think he is right. He says the biggest problem is in getting approval for a prop with more than 69" diameter and again, I think he is right.
Page 4 of 19 of TCDS 3A19 for the Cessna 150 does allow a Mac 1A90 CF 7535 on the O-200 seaplane with diameter between 73.5 and 75 inches.
And McCauley has issued a statement that the 1A90 and 1B90 are functionally equivalent (round tip vs straight tip).
My hunch is that somewhere around 7538 would make a good climb prop for an O-200 PA-11, as would a 7440.
Page 4 of 19 of TCDS 3A19 for the Cessna 150 does allow a Mac 1A90 CF 7535 on the O-200 seaplane with diameter between 73.5 and 75 inches.
And McCauley has issued a statement that the 1A90 and 1B90 are functionally equivalent (round tip vs straight tip).
My hunch is that somewhere around 7538 would make a good climb prop for an O-200 PA-11, as would a 7440.
Not an STC, either a Field Approval on a 337 or a DER Approval on an 8110-3. An STC is way more complicated, costs way more and takes at least 3 years to get through.
That shows there is no vibration issue between prop and engine. Length would still need to be confirmed (clearance in level attitude) as all the other J-3 and PA-11 props are 72 or 74". Finding a 1A90 might be an issue, McCauley stopped making them in favor of the 1B90. If you can find a 1B90CM with the right length and pitch that will work.
McCauley says the 1A90 and 1B90 are functionally equivalent and interchangeable.
I've run Jerry Burr's Mac 7535 on an O-200 J3 as a weekend experiment, using stock 8.00x4 tires. Ground clearance during high speed taxi (tail high/nose down) was adequate and not a problem (based only on visual observation of taxi - didn't measure it).
The Cessna 150 TCDS allows the 75" diameter to be cut back to as little as 73.5" minimum, and I have a strong preference for Mac 7440 props (the 7440 static pulls better than the 7535 up to about 2850 static rpm and isn't as prone to inadvertantly overtaching during climb and level flight). Do you think it might be possible to use the Cessna TCDS as supporting data for a 74" diameter instead of 75" ?
I may have a 74" 1A90 lying around. Don't remember, but will check. Do you think McCauley's letter of equivalence might help with getting approval for a 1B90 Klip-Tip?
I've run Jerry Burr's Mac 7535 on an O-200 J3 as a weekend experiment, using stock 8.00x4 tires. Ground clearance during high speed taxi (tail high/nose down) was adequate and not a problem (based only on visual observation of taxi - didn't measure it).
The Cessna 150 TCDS allows the 75" diameter to be cut back to as little as 73.5" minimum, and I have a strong preference for Mac 7440 props (the 7440 static pulls better than the 7535 up to about 2850 static rpm and isn't as prone to inadvertantly overtaching during climb and level flight). Do you think it might be possible to use the Cessna TCDS as supporting data for a 74" diameter instead of 75" ?
I may have a 74" 1A90 lying around. Don't remember, but will check. Do you think McCauley's letter of equivalence might help with getting approval for a 1B90 Klip-Tip?
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CAR 4 requires 9"of ground clearance with the airplane level and max gross weight gear spread and tire deflection.
McCauley TCDS P-842 Page 4 Note 6 has this to say about prop interchangeability:
NOTE 6. Interchangeable blades. Models 1A90 series and 1B90-CM, or 1C90-ALM and 1C90-CLM are sufficiently similar aerodynamically and vibrationwise to permit interchangeability in the same diameter and static r.p.m. without a flight test.
"CAR 4 requires 9"of ground clearance with the airplane level and max gross weight gear spread and tire deflection".
A-691 allows propeller diameters up to 76" on both the J3 and PA-11, so it would seem that adequate clearance for the 75" prop has been previously established and documented as meeting this criterion without additional testing.
So, since the 1A90 and 1B90 can be interchanged without flight test and since both props can be clipped to less than 74", it seems to me that this documentation could likely be used to install a 1B90 CM 7440 Klip-Tip on an O-200 PA-11 (as a personal aside, I've flown both the 7535 and the 7440 on an O-200 Cub, and the 7440 is a much better all around performance choice than the 7535 - I don't really like the 7535 because it is too easy to inadvertantly overtach it, plus the 7440 outpulls the 7535 up to rated rpm - if you shove the throttle up to 2850 in a 55mph climb, the 7535 pulls better, but that is in excess of rated rpm.).
NOTE 6. Interchangeable blades. Models 1A90 series and 1B90-CM, or 1C90-ALM and 1C90-CLM are sufficiently similar aerodynamically and vibrationwise to permit interchangeability in the same diameter and static r.p.m. without a flight test.
"CAR 4 requires 9"of ground clearance with the airplane level and max gross weight gear spread and tire deflection".
A-691 allows propeller diameters up to 76" on both the J3 and PA-11, so it would seem that adequate clearance for the 75" prop has been previously established and documented as meeting this criterion without additional testing.
So, since the 1A90 and 1B90 can be interchanged without flight test and since both props can be clipped to less than 74", it seems to me that this documentation could likely be used to install a 1B90 CM 7440 Klip-Tip on an O-200 PA-11 (as a personal aside, I've flown both the 7535 and the 7440 on an O-200 Cub, and the 7440 is a much better all around performance choice than the 7535 - I don't really like the 7535 because it is too easy to inadvertantly overtach it, plus the 7440 outpulls the 7535 up to rated rpm - if you shove the throttle up to 2850 in a 55mph climb, the 7535 pulls better, but that is in excess of rated rpm.).
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