Steen Skybolt

The Skybolt is a build-it-yourself experimental biplane available from Steen Aero Lab. The design has been in existence since the 1970s. Currently, there are about 450 licensed Skybolts in the United States, and another 200 or so around the world. It is used for both casual and aerobatic flying.

The Skybolt burns 15.6 gallons per hour of routine usage.


Subassemblies: Body +3, biplane Wings +3, 3 fixed wheels +0.

Powertrain: 134-kW HP gasoline engine with 134-kW aerial propeller, 2,000-kWs lead acid battery.

Fuel: 29 gallons aviation gasoline (Fire 13).

Occupancy: 1 NCS, 1 NPS.

Cargo: 1.25 cf (25 lbs.).


Armor F RL B T U

All: 2/3 2/3 2/3 2/3 2/3



Body: Medium range radio, navigation instruments, transponder, autopilot, 2-man environmental control.



Size: 19'x24'x7' Payload: 0.26 tons Lwt.: 0.9 tons

Volume: 275 cf. Maint.: 25 hours Price: $64,980


HT: 9. HPs: 40 Body, 58 each Wing, 4 each Wheel.


aSpeed: 190 aAccel: 5 aDecel: 27 gMR: 6.5 gSR: 2

Stall Speed: 55 mph. Take-Off Run: 480 yards. Landing Run: 240 yards.

gSpeed: 107 gAccel: 5 gDecel: 10 gMR: 0.5 gSR: 2

Ground Pressure High. 1/6 Off-Road speed.


Design Notes:

Body is 75 cf; wheels are 3.75 cf; wings are 24.78 cf. Structure is Extra Light, Standard with Good Streamlining. Armor is expensive metal. Mechanical controls. Design Empty weight is 1,945 lbs.; this was lowered 7% to the actual value. Stall speed was only 23 mph (or 49 mph using the calculation on p. W149); the real-world value is listed.



The plane can be constructed in a number of different ways. A larger powerplant (up to 261-kW) can be used, and the cockpit can delete the canopy. A 9-gallon auxiliary fuel tank can be fitted in the wing. And, of course, a smoke dispenser can be installed for skywriting!


From the Aerodrome for GURPS

2008 by Jim Antonicic