Different WAAS altitude readings

I'm using the 2004 FAR-AIM as a convenience...guess I should have used my
Summit CD-ROM which is updated quarterly.

Bob

"C J Campbell" wrote in message
...

"Bob Gardner" wrote in message
...
Can't address your problem, but AIM 1-1-20(a)(8) tells us not to use GPS
altitudes. Doesn't say anything about WAAS...yet.

1-1-20's title is "Wide Area Augmentation System (WAAS)." There is no
1-1-20(a)(8). 1-1-20(b) gives guidance and procedures for flying
approaches
with vertical guidance from WAAS and says that some installations of WAAS
may be certified for precision approaches as having greater accuracy than
barometric altimeters.