Concorde has an eye datum tool on the flight deck comprising solid 'spectacles' with a hole drilled in each 'eyepiece'. It is stowed in a pocket by the P1 foot well and us used by plugging it into the overhead centre panel and positioning the seat so the pilot's eyes line up with the holes in the datum.
I've asked a few, but I've yet to meet a Concorde pilot who used it!
Last edited by Shaggy Sheep Driver; 11th Feb 2013 at 09:44.