U2 Glide

[kangaroota]

How far could a U2 spyplane glide if it had an engine failure at its max operating altitude?

[milesharrison]

around 70,000ft max altitude x 28:1 best glide ratio
= 1960000ft or 371 miles (323 nautical)

but you had better leave a bit of altitude for the landing. impressive machine!

[BOAC]

...and the answer generally was 'not far enough'