Have the SA gear in my GS P-47. Mains work perfectly, but the TW is the problem......It retracts fine, but the steering rod binds and stalls the servo. Since it has only one air line, the Robart unit is out....I have tried vainly to get it to operate properly.., and have just been flying it extended... Hopefully, someone has found a solution to the steering problem on the Spring Air Tail Wheel and will share it with me