Re: Firmware bugs on 76CSx (and probably on all C*x models): No Great Circle routes!

Not that surprising. And, I don't think great circle or "direct" has anything to do with it. Your average speed during the 1st hour was much slower than your average speed for some given hour later in the flight (because it takes a while for an airliner to get up to speed). The estimated landing time is likely based on some average speed (not sure how long) and bearing. Airliners don't usually fly directly toward their destination for an entire flight. They zig-zag a bit. Furthermore, there may have been some wind differences that made differences in speed. These combination of factors could easily account for the differences in 15 and 9 estimated hours.

Arthur Hass

Terje Mathisen wrote:
Three days ago, on Sunday, I flew from SF to Oslo via Amsterdam, with a
new 76CSx gps. I was curious to see if this new model with the
significantly more sensitive gps engine would be better at maintaining
gps lock, even without using an external antenna under the window shade.

It worked _very_ well, with the gps on the table (window seat on the
north side) I got a continuous track from the point where we passed 10K
feet on the way up until I had to turn it off for landing.

However, when doing it it became painfully obvious that the gps assumed
a "direct" route, instead of the correct (and much shorter) great circle
which all my previous gps'es have used!

This meant that during the first few hours the estimated landing time
was badly off, on the order of 15 instead of 9 hours!

Terje
.

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