Flat-Back PA-11?

[1934A]

Does anyone here have, or know anyone with a flat-back PA-11? Mine is the only one I've ever seen, and i was just curious if this was a factory option, or if it was done at rebuild time somewhere along the way. I can't find anything in the logs about it getting done. The plane was used for spraying back in the 50's.

[BC12D-4-85]

In Roger Peperell's Piper Aircraft book he describes both J-3s (pp. 47 and 52) that were converted to dusters and sprayers. The pic on p. 52 shows a flat back J-3 duster NC7369H. There are PA-11 pics later from p. 81 on that show Whitaker dusters (N4999H) and sprayers (N5052H) but there's no direct view of the rear fuselage shape. I suppose having a flat deck to flow into the flat hopper bin cover would be a reasonable mod. TCDS A-691 under Items 6** lists several crop spraying and dusting alterations available. Might be part of that change.

Gary

[1934A]

I'll have to look through the logs again and see what sort of spray system was used, mught have been Whitaker.

Apparently there aren't too many of the flat-backs out there.

[BC12D-4-85]

Wouldn't it just be a matter of removing the former that creates the inverted-V of the upper fuselage? Then fabric the flat top over and meld with a flat hopper topper? My PA-18A was done like that.

Gary

[1934A]

Yes, as far as i can tell, the turtledeck is the only difference.

[WhiskeyMike]

Wouldn't it just be a matter of removing the former that creates the inverted-V of the upper fuselage? Then fabric the flat top over and meld with a flat hopper topper? My PA-18A was done like that.

Gary

Folks made their own hoppers etc for J-3's or later on used Sorenson tanks. I had a 135 HP modified J-3 that had been a "cut back" duster. No turtle deck at all, but a plywood deck on top of the longerons, behind the rear seat/baggage area to stand on while loading dust or liquid spray. There were quite a few of these around. I don't have a photo of mine, but here is one with the same mod -- Makes you think about how a J-3/PA-18 is actually constructed! Note the hinges on the hopper lid, and the step on the bottom longeron to help the loader jump up on the top of the fuselage when necessary.

[BC12D-4-85]

Thanks for the recall of tubing on an -A model vs standard airframe.....I got it wrong and forgot there's additional upper longeron tubing added for the flatback fuselage.

Gary

[LisaWi]

Makes you think about how a J-3/PA-18 is actually constructed!

You Tube: "Construction of a Light Aircraft (1943)" 27:23 (Filmed at Lock Haven by the Univ of PA School of Eng..)

https://www.youtube.com/watch?v=Q6q1VKsTeKQ