"Joseph Trepicone" <jtrepico@columbus.rr.com> wrote:

Hi,

Another builder and I are in the process of installing the rear pressure bulkheads (seat back and seat bottom) on our IV-P projects.  Based on the suggestion by Mark at Lancair we are moving the rear seat pressure bulkhead aft about 4 inches or so and bidding it in permanently.  The base of the seat back will be resting on the center of the gear box top rear brace. This makes the rear seat deeper and  increases the rear seat knee space.  We have the following questions:

1.  Any thoughts about moving the potential weight of 2 adults farther aft by 4 inches or so.  I'm considering installing the liquid cooled Zehrback TIIV-650 which is about 90 lbs. heavier (wet) than the TSIO-550 and so other builders using  this engine are relocating their battery or installing A/C units as far aft as possible.

2.  Any thoughts about permanently bidding in the seat back?  Does removing this pressure bulkhead benefit servicing the aircraft?

3.  We've never sat in the back seat of a IV.  Will this knee space be beneficial?

best regards,
Joe Trepicone