On Jan 9, 5:34 am, Mxsmanic wrote:

Sec. 91.21 Portable electronic devices.

(a) Except as provided in paragraph (b) of this section, no
person
may operate, nor may any operator or pilot in command of an aircraft
allow the operation of, any portable electronic device on any of the
following U.S.-registered civil aircraft:
(1) Aircraft operated by a holder of an air carrier operating
certificate or an operating certificate; or
(2) Any other aircraft while it is operated under IFR.
(b) Paragraph (a) of this section does not apply to--
(1) Portable voice recorders;
(2) Hearing aids;
(3) Heart pacemakers;
(4) Electric shavers; or
(5) Any other portable electronic device that the operator of the
aircraft has determined will not cause interference with the
navigation
or communication system of the aircraft on which it is to be used.
(c) In the case of an aircraft operated by a holder of an air
carrier operating certificate or an operating certificate, the
determination required by paragraph (b)(5) of this section shall be
made
by that operator of the aircraft on which the particular device is to
be
used. In the case of other aircraft, the determination may be made by
the pilot in command or other operator of the aircraft.

That is the Reg.
Self explanatory