The International Cessna^® 170 Association

I'm rebuilding a 54 with a Avcon 180HP conversion. The STC is SA806CE and it specifies a 74" hartzell. The 74" that came with the plane was tore up in the wreck so I'm shopping for a new prop. In the paperwork I also found a copy of Avcon STC SA749CE which allows the installation of a 76" Hartzell IF used in conjunction with Avcon STC SA421CE. My research on the FAA site says that the STC SA421CE is for the installation of a 180HP Lycoming but specifies "Landplane only". All of these STC's specify the same prop other than the blade length. Has anyone used a 76" Hartzell on STC SA806CE which does not have the "landplane only" limitation? Was this done via a field approval or through another STC? I spoke with Harry Dellicker and his STC uses the 76" prop without any limitations. I spoke to Hartzell and they have a new 80" with a blanket STC for installation on all 180HP STCs. I'm trying to figure out how to do this legally.

Lopez

I just happen to have a spare prop that came off of a c-170 with 180hp conversion.
Mine was / is a Bush conversion, but believe that they are the same if not extremely similar.

George I apologies up front if the above is not real accurate, but you have to have spent a whole day with Harry to understand how it is easy for an old brain to keep up this Harry's Histories.

But, as I remember it, Mr Harry D. told me that the Avcon version came about during a marital dispute and the wife got some portion of the business somehow and ended up calling it Avcon. Harry stated that for a while both companies had the same phone number in the same office. Just depended on who answered the phone as to which reply ya got.


If the prop is still needed, PM me or look up phone # in 170 assn directory

Chris C

Chris your story may be true, both the Bush and Avcon STCs are owned by the same people. But STC SA806CE and STC SA421CE are two completely different STCs,though they accomplish practically the same thing, and you can't mix and match components or limitations between them. You've got one or the other but not both.

What about using the MT prop? Isn't that a blanket STC for the 170s and 172s with 180hp O360 Lycs?

Lopez

You might list the required prop so I could see if the one I have would be useful.
I sure do not know, but the just might be the same prop for both STCs. ?!?

Just a thought

Chris C

HC-C2YK-1BF is the hub part number. F7666A are the blades. The blades may also have a suffix based on how much they have been cut. Going to pick one up today off of a husky but it is a full 76" length and I'm still trying to figure out how to do this without cutting it.

Do not cut it if it is good. I have a 74" with less than 50 hours since overhaul and new 'B' hub. It is in use but would consider a trade for the 76" if it is close to equal condition. If that is what you want??? Now if you can come up with one with the 8477-4 blades I'd perk up a bit more.

Lopez wrote:HC-C2YK-1BF is the hub part number. F7666A are the blades. The blades may also have a suffix based on how much they have been cut.

F7666A without suffix is the full-length 76". Suffix -2 is 74", and suffix -4 is 72". I don't know why the -2 was specified for SA806CE.

Dave

I've heard about the 80" prop blades for my Hartzel, but do not know anything else about them. Does anyone have experience/knowledge about this prop, ground clearance, performance, etc? I'd like to know more.


Neil

Contact David Stoots. He has an STC for the 80" Hartzell prop on a Lyc 0360. I have one on my plane and really like it. No clearance problems. Has worked flawless for 4 years now. Takes a dampener with the blades. Jon

Like wise, we have had the 80 " Hartzell for 6 or 7 years.. Can't be beat.. Very smooth and no limitations of the 2100-2200 rpm range..Great choice.

A little new life into an old thread, but I think it germane.

The STC for the 80 inch propeller is owned by Hartzell. The STC number is SA0111CH. Long title: Installation of Textron Lycoming 180 hp models: O-360-A1A, -A1C, -A1F, -A1G, -A1H, -A1P, -C1A, -C1C, -C1E, -C1F, -C1G with Hartzell propeller HC-C2YR-1BF/F8477-4, Hartzell damper assembly, and Hartzell spinners.

The reason why I'm interested in this is the airplane I'm looking at has the above STC (that's very good!). It also has the Bush Conversion, STC SA421CE – Lycoming O-360-A1A or O-360-A1D180 hp engine, O-360-B1B 168 hp engine and constant speed propeller. (170B LANDPLANE ONLY).

It sounds to me like this is not a worry in the sense that its the PROPELLER that is landplane only, NOT the conversion? I want to operate this particular airplane on floats eventually, so if the Bush Conversion can't be used on water this deal is sunk. Can anyone confirm my inference, and say why?

Thanks to all the good folks on this site!

My log book specifies dash 2 blades but measures 76 inches tip to tip. Sooooo if dash 2 is a 74 inch prop................?

Blue4 wrote:... I want to operate this particular airplane on floats eventually, so if the Bush Conversion can't be used on water this deal is sunk. ...

Was that an intentional PUN?

The reason some amphib's use shorter props is to avoid water-erosion, usually caused by whirlwind effect during acceleration. The water is especially damaging to the prop tips, which once damaged, offer increased risks of tip-seperation in-flight. This could cause the loss of the entire engine if not the entire airplane.

Blue4 wrote:A little new life into an old thread, but I think it germane.

No, it's the MT prop that's German. The Hartzell is made in the USA. Sorry, couldn't resist. The STC limits one to using PK2300 or Wipline 2100 floats. Looks to me that one could even get it with a reversible pitch feature which would be cool. http://www.mt-propeller.com/en/entw/reversible.htm I heard MAF tried installing a reversible prop years ago on a C-185 landplane. Apparently it was too squirrelly. Maybe if they would have added a locking tailwheel it might have worked.

Blue4 wrote:The reason why I'm interested in this is the airplane I'm looking at has the above STC (that's very good!). It also has the Bush Conversion, STC SA421CE – Lycoming O-360-A1A or O-360-A1D180 hp engine, O-360-B1B 168 hp engine and constant speed propeller. (170B LANDPLANE ONLY).

It sounds to me like this is not a worry in the sense that its the PROPELLER that is landplane only, NOT the conversion? I want to operate this particular airplane on floats eventually, so if the Bush Conversion can't be used on water this deal is sunk. Can anyone confirm my inference, and say why?

Yes, that is rather ambiguous. You might try calling the Wichita FAA office listed on the STC (316) 946-4100 because you'll never get in touch with Robert or Barbara Williams.