We often get inquiries from potential builders along the lines of "Hi, I'm 6 foot 8... can I fit in a Skybolt?" or occasionally we also get "I'm really short, do I need to modify the plane in any way?" As we looked at the seat setup, we made the decision that there was really no good reason that both these folks shouldn't be able to fly the same Model 14 easily, and without having to pull out the welding rig in between. It's a shame, but most aerobatic homebuilts (and quite likely, most homebuilts in general) don't provide for much, if any, seat adjustments beyond changing the amount and thickness of the seat cushions.
Of course, any adjustable seat system must be sturdy enough for aerobatics, and work well enough to justify the added weight and building time. And it should be easy enough to use that the owner won't curse his or her decision to install it in the first place.
What we came up with is one of the most configurable systems we've seen, and it's really not terribly difficult to build once the geometry is laid out. (Yes, we did go through several iterations until we got it just right.) All adjustments are independent, which allows for a great many combinations of positions.
The rear seat can be adjusted fore and aft at both the top and bottom of the seat back, and the seat bottom can be adjusted up and down on both the front and rear edges. This allows the pilot to have total control over the fore-aft position of the seat, the height of the seat pan, and the angles of the seat's bottom and back.
There is slightly less adjustability to the front seat, which is permanently hinged to the fuselage at the top of the seat back (necessary since immediately behind that lies the instrument panel, and there isn't room for the telescoping fore-aft adjustment strut as in the rear seat). The bottom of the strut connecting to the front of the seat pan is also fixed to a fuselage cross-piece. However, the height of the front and rear of the seat pan, as well as the fore-aft position of the bottom of the seat back is adjustable.
Adjustments are made by a simple system using locking pip pins going through holes to lock in the location for the various seat adjustments. This is strong, sturdy, and very unlikely to loosen on its own even under serious vibration and G loads, yet the seat is very easy to adjust in a multitude of ways to accommodate most pilots. The seat frames and mounts are all made of 4130 chromoly.
We feel that this system will be very adaptable and is well within the average builder's capability to get right during construction.