(a) The maximum altitude up to which operation is allowed, as limited by flight, structural, powerplant, functional or equipment characteristics, must be established.
(b) A maximum operating altitude limitation of not more than 25,000 feet must be established for pressurized airplanes unless compliance with Sec. 23.775(e) is shown. [Doc. No. 26269, 58 FR 42166, Aug. 6, 1993]