The Spratt Controlwing Flying Boat — plans and manual

Controlwing N107GW

Controlwing flying boat – N107GW

George G. Spratt’s Controlwing flying boat was developed from 1939, with plans drawn up in 1972–1973. Bill Wolfe used these drawings to build N107GW in the late 1990s. Sadly, he died in 2014.

Bill extensively annotated the plans and marked many personal changes to the original Spratt 1973 design, and kindly made them, and an 84 page construction and information manual with additional notes and drawings, available for non-commercial use.

See the web site for videos of Spratt Controlwing flying boats, the Spratt and Controlwing History, the Spratt–Wright connection, plus other historic materials and general information.

The plans and manual are both in two parts, all Adobe PDF files:
    controlwing-plans-part1.pdf   (11 pages, 12 MB)
    controlwing-plans-part2.pdf   (20 pages, 13 MB)
    controlwing-manual-part1.pdf   (79 pages, 12 MB)
    controlwing-manual-part2.pdf   (5 pages, 15 MB)

The pages in the two parts of the plans are as follows:

Part 1
  1. General view – inboard profile
  2. Hull lines – side view
  3. Hull lines – top view
  4. Front, side, and top views
  5. Wing assembly and control rod fitting detail 
  6. Hull sections
  7. Wing and spar details
  8. Wing ribs, etc.
  9. Drive shaft pulley
  10. Distributor modification (80HP Mercury)
  11. Engine cradle, etc.
  1. Mast assembly
  2. Drive shaft, propeller stub, etc.
  3. Wing struts (left side)
  4. Mixer assembly
  5. Collective pitch control and throttle 
  6. Ribs
  7. Wooden prop ring
  8. Wing fittings 1
  9. Wing fittings 2
  10. Foam hull construction
  1. Propeller A-frame support 
  2. Wing fittings 3
  3. Hull fittings for wing struts
  4. Mast clamp and fittings
  5. Hull fittings
  6. Steering wheel assembly
  7. Forward control pulleys
  8. Radiator
  9. Rear control pulleys
  10. Engine, drive belt, etc.

See also:

Thanks, too, to A&B Reprographics, Inc., who digitized the plans and kindly provided them for this site.

Mike Cowlishaw, April 2009. This page was last edited on 2015-02-22.