The Cessna 120-140 Association Forum

I've read the STC, done some homework, etc. Heard somewhere it allowed a GW increase to 1500. Cant' find that anywhere. Any truth to that?

Thanks

When I say I’ve read the STC, merely the "official looking certifcate" one puts in the logs. How do I find the actual "installation instructions"?

Aplogize in advance for the flurry of questions.

Scott

Here's mine from the 337 done ages ago but I don't think there was a GW increase. Randy Thompson now has this STC for the 0-200 installation, I don't recall an increase on it either.

This will get you to the FAA site, enter SA547EA in the search, gives you the fancy paper with some info but not the instructions, you get that from Randy I suspect.

https://rgl.faa.gov/Regulatory_and_Guid ... enFrameSet

sbmackie wrote: ↑Tue Dec 15, 2020 2:23 pm Heard somewhere it allowed a GW increase to 1500.

Not true.

Drop the mike...

The gross limit is a structural limit. The only modification I am aware of that changes it is adding floats. Why? The floats act as an airfoil and reduce the stress on other parts of the plane.

He may have been mixing it up with the A model.....

Spoke to The Man himself (Mr. Thompson, out in Cali). Fine gentleman. Nope, no increase in gross weight. End of story.

Scott

This STC calls for a DCM prop of 52" pitch. What's the legality of installing a 50" pitch DCM prop. Other STCs that specify a 50-54" prop specify the MCM prop but have no mention of the DCM. Any way to get the 50" DCM prop on an o-200 legally under any of the STC's?

mdtrn wrote: ↑Fri Dec 25, 2020 6:20 pm This STC calls for a DCM prop of 52" pitch. What's the legality of installing a 50" pitch DCM prop. Other STCs that specify a 50-54" prop specify the MCM prop but have no mention of the DCM. Any way to get the 50" DCM prop on an o-200 legally under any of the STC's?

While I don't know what the STC holder may be required by FAA if deviating from the STC, I'd expect that any prop change OK from that specified would have to be in writing, direct from the STC holder. Mac

If it's not listed in the STC, you'll need a field approval. Depending on what data you can come up with (same engine and prop approved on similar airframe...) obtaining approval could be anything from a slam dunk to impossible.

The McCauley Props in my STC547EA allow 50 inch pitch. The Sensenich can also be set to 50 inch pitch.
I added propellers to the STC after I bought it. There is a pitch range specified in the paperwork.