wrote:

Most of the USAF aircraft aren't new, and the USAF is doing a lot of
upgrades to a lot of aircraft, not just special-use.

I don't know much about what the USAF is doing other than a Lt COL who
is at their instrument procedures group told me that performance-based
RNP procedures would be limited to a small segment of USAF aircraft. I
don't know what he really meant by that.

Fact is that retrofitting any aircraft can be expensive and even the
USAF has to consider cost. If the money is not there or the benefit
does not justify the cost then you don't upgrade.

Ron Lee