Flight manual supplement questions

[timrev8]

Hi All, my brother and I recently purchased a 172m factory float plane with 180hp Lycoming with the Bob Williams avcon STC 647CE. The Airplane also has a STOL Kit and some other minor mods.
My brothers instructor says we need the "flight manual supplements" and we are not finding what we need in the log book collection. I have a folder that says "flight Manual supplements" but it doesn't seem to include anything that gives us updated stall speeds, fuel burn ect. We do have a checklist that includes the fuel pump and some other things that are different from the original POH.
How does flight manual supplements work? How do we add it all up to get updated flight characteristics, V speeds, fuel burn ect. ?
thank you
Tim

 

[ateamer]

If the engine STC (Williams) is the same as for my Cessna 175, there is no flight manual supplement, nor any performance data. The Horton STOL kit is the same. It wasn’t required on STCs until 1980-ish.

 

[midlifeflyer]

Flight manual supplements are basically the POH for new equipment. Add a GTN650 to your 1981 Cherokee, you will have a flight manual supplement for it. Add a different prop that original equipment, it will have a Supplement too. The STC itself, and the Form 337 filed by the installer, should specify whether there is a supplement or not.

Since the POH format became standard, the Supplements are generally in the same format. General information, Limitations, Emergency Procedure Checklists, Normal Procedure Checklists, etc... Those sections will tell you what changes the new equipment makes to the original POH contents. And they are typically should be located at the end of the POH, after the tab that says "Supplements," which should have a table of contents or log.

To give one example, a stock Diamond DA40 comes with a three-bladed propeller which has a 2400 RPM continuous power limitation. The US models typically come with a Hartzell 2-bladed prop with not limitation on using the full 2700 RPM all the time.

Legally, they are part of the POH and part of the FAR 91.9 requirement to have the manual available.

And many, including the FAA, say it's essential to modify your operations checklists to reflect newly installed equipment.

 

[MauleSkinner]

I have a folder that says "flight Manual supplements" but it doesn't seem to include anything that gives us updated stall speeds, fuel burn ect.

Most performance-enhancing mods for light GA airplanes won’t provide changes to aircraft performance numbers…generally the performance section of the supplement will say something to the effect of performance will be the same as or better than the unmodified airplane, and leave you to your own devices.

 

[midlifeflyer]

Most performance-enhancing mods

Interesting observation. I've seen both. I recall the installation of an IO-550 in a Debonair I used to fly had the "same or better" language. OTOH, the Hartzell prop on the DA40 comes with a 10-page AFMS. I'm not sure if I've seen enough to say there is more of one than the other. I wonder if some of that is age, with newer STCs including an AFMS, like newer aircraft having a POH to begin with?

Out of curiosity, I googled the Powerflow Systems exhaust as a relatively new performance STC (definitely newer than that Deb ). Sure enough

 

[MauleSkinner]

Interesting observation. I've seen both. I recall the installation of an IO-550 in a Debonair I used to fly had the "same or better" language. OTOH, the Hartzell prop on the DA40 comes with a 10-page AFMS. I'm not sure if I've seen enough to say there is more of one than the other. I wonder if some of that is age, with newer STCs including an AFMS, like newer aircraft having a POH to begin with?

Could be. Most of the VG STCs I’ve seen don’t change performance data (one brought back manufacturer’s data that had been removed at some point), the Petersen canard 182s, Horton STOL on my 150, a couple of engine mods, all “same or better.” Some VG mods show a Vmc change, some don’t; I don’t recall any that re-marked the airspeed indicator for stall.

Might be related to CAR3 vs Part 23, too.

 

[midlifeflyer]

Horton STOL on my 150,

Here's part of the Horton STC for the Cessna 210. OTOH, the one I found for the 172 series does not contain that requirement.

 

[MauleSkinner]

Here's part of the Horton STC for the Cessna 210. OTOH, the one I found for the 172 series does not contain that requirement.
View attachment 139423

But does the supplement change the performance data? Those are the changes that I don’t generally see,

 

[midlifeflyer]

But does the supplement change the performance data? Those are the changes that I don’t generally see,

I searched a bit but could not locate a copy of the STOL AFMS. And yeah, even with an AFMS requirement, the AFMS could say (this example is not for a performance mod)

 

[timrev8]

Thanks Guys!!!
Sooooooo, if i understand correctly, my STCs probably dont have a AFMS requirement in the Limitations and conditions section of the STC. Ill Look and post some pics