M.Goodall, A.Tagg British Aircraft before the Great War (Schiffer)
Deleted by request of (c)Schiffer Publishing
SIM glider (A. Sim, Sundridge Park, Kent)
This amateur built two bay biplane glider was made originally with only a boxkite tail with three fins on booms, but trials suggested that the tail was too heavy and a front elevator was then added. The wings were built with the spars at the extreme edges of the chord, and were single surfaced with no camber. The operator stood in the gap in the lower center section with the machine resting on bamboo skids at the center and wing tips. Bamboo was also used for the structure.
The machine was flown as a kite and lifted off with one person aboard.
Area 253 sq. ft
Gap 4ft 9in
Area of tailplane 42 1/2 sq. ft
Length less elevator 17ft 4in
P.Lewis British Aircraft 1809-1914 (Putnam)
The Sim Glider was built during 1909 at Sundridge Park, Kent, by A. Sim, and was modified at the end of the year by the addition of a front elevator. Span, 21 ft. Length, 17 ft. 4 ins. Wing area, 253 sq. ft.
The two-seat Sim Biplane was constructed by A. Sim of Sundridge Park, Kent, during 1909, and was composed of bamboo and fabric.
Flight, January 8, 1910
I receive your paper as a member of the Aero Club, and have read with great interest Mr. Horace W. Vaughan's article. During the last few months my brother-in-law and I have been experimenting with a glider of almost identical design, and with very similar results. The frame of our glider was of bamboo throughout, with piano wire stays. It has had plenty of falls, and many struts and stays have been broken from time to time, but these can be easily and quickly replaced. Since September it has been left in the open under an old oak tree, and still is apparently none the worse. We have had several successful flights with a passenger, but the pressure of the wind, acting against the men towing on the ropes, had to be sufficiently strong to enable the glider to support the passenger at the same angle that it assumed when flown without the passenger. Otherwise it would not rise. We attributed this at first to the excessive weight of the tail. To rectify this we added a front elevator, consisting of a single adjustable plane. Greatly to our disappointment this made matters no better. The glider still would not lift except at the same large angle. Further, the increased surface made it impossible to make good progress against the wind unless we had several men on the ropes. Without the elevator two men were sufficient. To try and discover how much pressure was required to maintain longitudinal balance we removed both tail and elevator, and flew the main planes by themselves. To steady and prevent them tipping over, we attached a cord to the middle of the lower back strut. With two men towing the front ropes, and a third regulating the cord from the rear, the main planes flew very steadily. We were greatly surprised at the very small pressure that was required on the cord behind to maintain the planes at the correct angle. This convinced us in the idea that our tail was by far too heavy. We are now building a light tail, with a single plane and a vertical panel on the Santos Dumont principle.
Sundridge Park. A. SlM.