NavList:

Hi David

Yes - further research indicates that drift sight and sextant viewed through same instrument panel portal - but separate instruments - any suggestion of using a hand held sextant seems far fetched given the pilot wears a full body pressure suit and the U2 canopy and cockpit just doesn't allow the movement needed to 'take a star shot'.

Here is an article on the Perkins-ELmer Mk I Drift sight and its mods and it notes that the sextant was not part of the drift sight - though you looked through the same viewing port on the instrument panel either the driftsight or sextant but not both and they were 2 separate instruments.

Quite interesting reading especially using Nitrogen to purge at startup eventually enabling both systems to be purged.

Interesting the name Mk I - typically Mk I in flying was always reference to your eyeball.

https://blackbirds.net/u2/chapmans_driftsite.html

I have read many books on the U2 known affectionately as the 'Ghost Lady' - it was operational for a huge period not unlike the B52 bomber ..... it is a fascinating read not unlike the now stealth bomber and stealth fighters.

Howard G