Except as provided in paragraph (d) of this section, each person
operating an aircraft in Class A airspace must conduct that operation
under instrument flight rules (IFR) and in compliance with the following:
(a) Clearance. Operations may be conducted only under an ATC
clearance received prior to entering the airspace.
(b) Communications. Unless otherwise authorized by ATC, each
aircraft operating in Class A airspace must be equipped with a two-way
radio capable of communicating with ATC on a frequency assigned by ATC.
Each pilot must maintain two-way radio communications with ATC while
operating in Class A airspace.
(c) Transponder requirement. Unless otherwise authorized by ATC,
no person may operate an aircraft within Class A airspace unless that
aircraft is equipped with the applicable equipment specified in §91.215.
(d) ATC authorizations. An operator may deviate from any
provision of this section under the provisions of an ATC authorization
issued by the ATC facility having jurisdiction of the airspace concerned.
In the case of an inoperative transponder, ATC may immediately approve an
operation within a Class A airspace area allowing flight to continue, if
desired, to the airport of ultimate destination, including any
intermediate stops, or to proceed to a place where suitable repairs can be
made, or both. Requests for deviation from any provision of this section
must be submitted in writing, at least 4 days before the proposed
operation. ATC may authorize a deviation on a continuing basis or for an