AD 75-15-05

75-15-05 MCDONNELL DOUGLAS, LOCKHEED, BOEING, AND AIRBUS INDUSTRIE: Amendment 39-2262 as amended by Amendment 39-2739. Applies to McDonnell Douglas Model DC-10 Series, Lockheed Model L-1011 Series, Boeing Model B-747 Series, and Airbus Industrie Model A-300 Series airplanes certificated in all categories.

Unless already accomplished, compliance is required on or before December 31, 1977, or in accordance with a schedule of accomplishment approved by the Chief, Aircraft Engineering Division, FAA Western Region, for McDonnell Douglas Model DC-10 Series and Lockheed Model L-1011 Series airplanes; the Chief, Engineering and Manufacturing Branch, FAA Northwest Region, for Boeing Model B-747 Series airplanes, or the Chief, Aircraft Certification Staff, FAA Europe, Africa, and Middle East Region, for Airbus Industrie Model A-300 Series airplanes, but not later than December 31, 1978.

To improve the capability of the passenger and crew compartment floors to withstand, without collapse, an in-flight depressurization caused by the sudden opening of a large hole in the lower deck cargo compartment, comply with paragraphs (a) or (b) as appropriate:

(a) Incorporate the modification specified in paragraph (a)(1), taking into consideration the factors specified in paragraphs (a)(2) and (a)(3):

(1) Provide additional venting capability or an increase in floor strength, or both, as necessary, to prevent floor collapse caused by the decompression effects resulting from a sudden large in-flight opening in any portion of any lower deck cargo compartment.

(2) The size of openings to be considered must include the maximum size opening expected in service, but the maximum size opening considered may not have an area of less than 20 square feet.

(3) Each compartment and ambient condition pressure differential expected in service must be considered.

(4) In showing compliance with paragraphs (a)(1), (a)(2), and (a)(3), damage to the floor is permitted if the degree of damage will not preclude continued safe flight and landing, or result in injury to occupants.

(b) For the all-cargo version of each of the above airplanes, it is satisfactory to comply with paragraph (a)(2) by showing that continued safe flight and landing is assured and that no injury to any occupant results in lieu of showing no floor collapse. Appropriate limitations must be added to the flight manual for the particular airplane approved under the all-cargo provisions.

(c) The modification and determinations required under paragraphs (a) and (b) of this AD must be approved by the Chief, Aircraft Engineering Division, FAA Western Region, for McDonnell Douglas Model DC-10 Series and Lockheed Model L-1011 Series airplanes; the Chief, Engineering and Manufacturing Branch, FAA Northwest Region, for Boeing Model B-747 Series airplanes; or the Chief, Aircraft Certification Staff, FAA Europe, Africa, and Middle East Region, for Airbus Industrie Model A-300 Series airplanes.

Amendment 39-2262 became effective August 11, 1975.

This amendment 39-2739 becomes effective November 3, 1976.