Not that familiar with the 757 but GPS displays GS. Add or subtract winds to
get TAS, then correct for density (divide by SMOE) to get IAS?CAS. Heard it
suggested you could also depressurize and use the cabin altimeter for
altitude. Or, convert cabin altitude into aircraft altitude if the chart is
available.
Curt


"Emilio" wrote in message
...
A portion of thread from different news grope:

loss of a 757 a few years ago in which clogged pitot tubes
caused bad overspeed warnings; the Turkish crew pulled
back the power and stalled and crashed. It was later determined
that the A/C had sat for a month and insects had gotten into
uncovered pitot tubes.

With aircraft equipped with GPS that shows your true speed, can you fly by
it when pitot tube is down?

Emilio.