Eye Height Reference Device - Boeing 737
Hello All:
FAR 25.773 (d) mandates installation of a 'fixed marker or other guide' in transport category aircraft to ensure that the pilots adjust their seating position such that they are positioned at the design eye reference point.
Looking at pictures of 737-500 flight compartments, I cannot see any evidence of an 'occluded sphere' type reference device installed on the windshield center post. Did Boeing use a different type of 'fixed marker or other guide' on these early 737s to comply with this FAR, and if so, what methodology did they use? Or, were these aircraft built to a certification basis that preceded publication of FAR 25.773 (d)?
Many thanks in advance for any light that an expert could shed on this question.
(Question was originally posted in the 'Flight Test' forum, but received no response there.)