"Dave S" wrote in message
k.net...

So.. if the ATIS says "contact ground/clearance" prior to engine start,
does that constitute instruction from "air traffic control" which must be
complied with except in an emergency?


No. FAR 91.123(b) states, "Except in an emergency, no person may operate an
aircraft contrary to an ATC instruction in an area in which air traffic
control is exercised." Ramps are not areas in which air traffic control is
exercised. Note that a taxi clearance is only required to operate on a
runway or taxiway. If I can taxi on a ramp without contacting ground
control I can certainly start an engine without calling them.



and is not obtaining (and complying with any instructions on) the ATIS
failure to obtain all relevant information regarding the proposed flight?


Not obtaining it might be, not complying with it is not.



Can you reconcile these concepts (loosely paraphrased from the part 91
rules regarding ops) with what you are saying that there is "no
requirement to call ground prior to engine start" when in some
circumstances there appears to be?


If there is a requirement to call ground prior to engine start it will be
found in the FARs. You will find no such requirement there.

The local flying field here has a statement on the ATIS telling departures
to five specific airports to advise ground control five minutes prior to
engine start. It's for flow control purposes, the five airports are those
for which a flow release is required. The only penalty for not calling
ground prior to engine start is the potential fuel wasted on the ground
waiting for the release time.