jjohnson

Mil Std 33574, Fig. 3. sets up basic cockpit dimensions for USAF stick-controlled, fixed wing aircraft. The basic measurement point is at the intersection of the seat pan and the seat back, called the Neutral Seat Reference Point (NSRP). It is nominally 22 cm (8 2/3 or 8.66 inches) above the floor or heel rest plane. THis is a very useful regulation in laying out cockpits, power and flight controls, visibility requirements, helmet clearance requirements, cockpit widths etc.