"Sam Spade" wrote in message
...
Stan Prevost wrote:

"Sam Spade" wrote in message
...
Example:

http://tinyurl.com/y68phr



A very nice example it is, when comparing to the NACO chart
http://tinyurl.com/yfygkv .

NACO computes the descent from the FAWP to the stepdown fix. Jeppesen
computes it from the stepdown fix to the TCH at the runway.

I wonder how the GPS units present the glide slope: 3.67 deg from the
FAWP or 3.61 deg from 0.1 nm after the FAWP. There is only about 30 feet
difference at the stepdown fix between starting the two descent angles at
the FAWP.

NACO is not presenting a VNAV path, rather the descent angle from the FAF
to TDZ elevation.


Maybe so, but the angle seems to compute out closer to the descent angle
from FAWP to stepdown, limited by the precision in the numbers on the chart.

The question remains, though, where does the glideslope begin in the GPS
unit: from the FAWP or from the point 0.1 nm after that waypoint?