Once did a trip in the T5 Frightning in fishbowl conditions. Low level OPEX off Flambo with Staxton doing broadcast, ships looking like they were above, no horizon and the altimeter showing us at 50 fathoms.
Pilot working out were we and txt were on his knee pad, whilst working the AI23 hand controller, head alternating between rubber scope eyepiece, instruments and sky whilst talking me through the intercept. Asked him how he knew what height we were at and he told me he was watching the size of our shadow on the surface.
Understood that day why they were nicknamed one armed paper hangers.