The AI. In reading the FAA Instrument Flying Handbook, it says you can
derive all of the necessary flight information from the other 5 instruments.

Chris G.

Chris W wrote:
Brad Zeigler wrote:

Hobbs meter.


I guess I need to be more specific. If, before an IFR flight, you had
to remove one of the instruments in the image linked below, which one
would it be?

http://www.thewishzone.com/aviation/...nstruments.jpg

Other than a compass, and navaid radios you have no other device to
prevent you from impacting the ground unexpectedly. To be even more
clear, you don't have a GPS!