EDR wrote

Gee...EDR, you really disappoint me. :-)

One of the regs says that you have to advice ATC of any airspeed
deviations of +/- 10% (someone correct me if I am wrong,

Well, you asked for it! Advice is a noun. The word that you wanted
to use is advise, the verb.

When you fill in the AIRSPEED box, do you give the actual indicated
airspeed for your cruise power setting?

Nope! You use TAS, which is CAS corrected for pressure altitude and
temperature. Hmmm....how do you get from IAS to CAS???? :-)

If you use the actual indicated airspeed, the math is not correct for
the time enroute.

Of course, if you are using indicated airspeed, the math isn't correct
anyway.

If you use the actual airspeed and the calculated no-wind time enroute,
you mess up the system in the event of loss of comm, since you will not
be where they expect you in the elapsed time.

If you have "advised" ATC of a change in TAS, they recompute your ETA.


Further, in these days of RADAR, LORAN and GPS, do you advice ATC of
the groundspeed deviation from the airspeed?

EDR....you really aren't a pilot are you?

Bob Moore
ATP CFI