In Plain English
FAR 91.1505 applies to operators of certain older pressurized transport-category airplanes — including the Boeing 707, 720, 727, 737, and 747, McDonnell Douglas DC-8, DC-9/MD-80, and DC-10, Airbus A300 (excluding -600 series), BAC 1-11, Fokker F28, and Lockheed L-1011.
Once one of these airplanes reaches its specified flight cycle implementation time (or May 25, 2001, whichever is later), it cannot be operated unless repair assessment guidelines for the fuselage pressure boundary — meaning the fuselage skin, door skin, and bulkhead webs — have been incorporated into the operator's inspection program. Those guidelines must be approved by the responsible Aircraft Certification Service office for the airplane's type certificate.
Why it matters: As pressurized aircraft accumulate cycles, repaired areas of the pressure vessel can become fatigue-critical. This rule ensures aging-aircraft repairs are tracked and re-inspected before structural failure becomes a risk. Cycle thresholds vary by model — for example, 15,000 flights for the 707 and 747, 60,000 for the 737 and DC-9/MD-80, and model-specific limits for the A300.
Regulation Text
14 CFR § 91.1505§ 91.1505 Repairs assessment for pressurized fuselages.
(a) No person may operate an Airbus Model A300 (excluding the -600 series), British Aerospace Model BAC 1-11, Boeing Model 707, 720, 727, 737 or 747, McDonnell Douglas Model DC-8, DC-9/MD-80 or DC-10, Fokker Model F28, or Lockheed Model L-1011 airplane beyond applicable flight cycle implementation time specified below, or May 25, 2001, whichever occurs later, unless repair assessment guidelines applicable to the fuselage pressure boundary (fuselage skin, door skin, and bulkhead webs) are incorporated within its inspection program. The repair assessment guidelines must be approved by the responsible Aircraft Certification Service office for the type certificate for the affected airplane.
(1) For the Airbus Model A300 (excluding the -600 series), the flight cycle implementation time is:
(i) Model B2: 36,000 flights.
(ii) Model B4-100 (including Model B4-2C): 30,000 flights above the window line, and 36,000 flights below the window line.
(iii) Model B4-200: 25,500 flights above the window line, and 34,000 flights below the window line.
(2) For all models of the British Aerospace BAC 1-11, the flight cycle implementation time is 60,000 flights.
(3) For all models of the Boeing 707, the flight cycle implementation time is 15,000 flights.
(4) For all models of the Boeing 720, the flight cycle implementation time is 23,000 flights.
(5) For all models of the Boeing 727, the flight cycle implementation time is 45,000 flights.
(6) For all models of the Boeing 737, the flight cycle implementation time is 60,000 flights.
(7) For all models of the Boeing 747, the flight cycle implementation time is 15,000 flights.
(8) For all models of the McDonnell Douglas DC-8, the flight cycle implementation time is 30,000 flights.
(9) For all models of the McDonnell Douglas DC-9/MD-80, the flight cycle implementation time is 60,000 flights.
(10) For all models of the McDonnell Douglas DC-10, the flight cycle implementation time is 30,000 flights.
(11) For all models of the Lockheed L-1011, the flight cycle implementation time is 27,000 flights.
(12) For the Fokker F-28 Mark 1000, 2000, 3000, and 4000, the flight cycle implementation time is 60,000 flights.
(b) [Reserved]
[Docket 29104, 65 FR 24125, Apr. 25, 2000; 65 FR 35703, June 5, 2000; 65 FR 50744, Aug. 21, 2000, as amended by Amdt. 91-266, 66 FR 23130, May 7, 2001; Amdt. 91-277, 67 FR 72834, Dec. 9, 2002; Amdt. 91-283, 69 FR 45941, July 30, 2004. Redesignated and amended by Amdt. 91-297, 72 FR 63410, Nov. 8, 2007; Docket FAA-2018-0119, Amdt. 91-350, 83 FR 9171, Mar. 5, 2018]