Federal Aviation Administration Regulations
14 CFR 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.
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Unfortunately, most airlines do prohibit the use of scanners at any time on board. The people saying the rule is stupid because you're sitting so far behind the cockpit don't know what they're talking about. The communications, VOR, ILS localizer and ILS glideslope antennas may be located very far back on top of or below the fuselage. Although the rule is still stupid in my opinion, I wouldn't want to tempt fate by sitting directly above the glideslope or localizer antennas blasting the scanner during a catagory II or III ILS approach in instrument meteorological conditions. Just common sense.
Still, the rumor others are saying that you won't hear anything unless you hold the antenna directly up to the window is also unfounded. A friend :wink: had no trouble listening to ATC TRACON and ARTCC controllers with headphones from a window seat, with the scanner under the seat in a backpack in a Boeing 737-700. The reception was not the greatest, but certainly very recievable.