Doyn conversions on seaplanes

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Dwyer
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Doyn conversions on seaplanes

Post by Dwyer »

STC SA421CE stipulates "LANDPLANE" only for the 180HP with constant speed prop conversion. Would anyone have paper work allowing this conversion on the 170B with floats?
Thanks,
Dwyer
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minton
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Re: Doyn conversions on seaplanes

Post by minton »

As I recall, Bush, Avcon and Doyn conversions are very similar if not an exact match or maybe were renamed after a sale of the STC's. Maybe the Avcon guys can help you out.

The Del-Air has some major structural requirement differences that would disqualify it's paperwork for references to your seaplane application.

Also there may be a chance that later Doyn paperwork might include seaplanes due to a further "refinement" to that specific STC. There again maybe the Doyn guys can help you out with that avenue.

If it becomes necessary for you to obtain a "Field Approval" by comparison of Doyn vs Avcon blue prints could work for you if you have a good A/I PMI.
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Dwyer
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Re: Doyn conversions on seaplanes

Post by Dwyer »

Minton,
There are a good number of these conversions which are designated "Landplane Only". I know there are quite a few of these conversions (Avcon, Doyn and Bush) on 170's flying floats. If anyone would have an airplane flight manual supplement or some other form of paper work which allowed this conversion for seaplanes, I would appreciate a copy.
Thanks,
Dwyer
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Dwyer
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Re: Doyn conversions on seaplanes & STC SA421CE

Post by Dwyer »

Hello,
Please see the attachments to clarify the issue of "LANDPLANE ONLY" attached to STC SA421CE. This information came from Jeff J of the FAA. He does not mind sharing this information to all members of the 170 Association and having it the Association library.
Hope this helps all you fellows with this conversion and who were wondering about the "LANPLANE ONLY" issue on the STC.
Finally flying on floats!
Dwyer
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Bruce Fenstermacher
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Re: Doyn conversions on seaplanes

Post by Bruce Fenstermacher »

Very interesting. Good on you that your airplane is not restricted. I'll probably copy these documents to our library. Thanks
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blueldr
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Re: Doyn conversions on seaplanes

Post by blueldr »

The only Doyn conversion I've ever seen used the Lycoming O-340 engine of about 160HP. Is yours an o-340 or an o-360? Perhaps they never tried to certify the O-340 for seaplane use.
BL
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Dwyer
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Re: Doyn conversions on seaplanes

Post by Dwyer »

I have a 1955 170B with the O-360 A1A and the constant speed prop
Dwyer
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Ron Smith
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Re: Doyn conversions on seaplanes

Post by Ron Smith »

Dwyer wrote:I have a 1955 170B with the O-360 A1A and the constant speed prop
Dwyer
What stc did you use to do this? Are you happy with it? Thanks Ron Smith
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