AD 61-05-02

61-05-02 DOUGLAS: Amdt. 259 Part 507 Federal Register March 3, 1961, as amended by amendment 39-3354. Applies to All Models DC-6 Series Prior to Serial Number 44888 and DC-7 Series Up to Serial Number 44872 Having 32,000 or More Hours' Time in Service Including Military Models.

Compliance required as indicated.

Instances have been reported of loss of emergency exit doors during pressurized flight due to failure of the bottom hinge fitting with subsequent failures of the top hinge fitting. To preclude further occurrences, the following shall be accomplished on the emergency exit door hinges:

(a) Unless already accomplished within the last 350 hours' time in service, emergency exit door hinges with less than a 1-inch door skin recess radius shall be inspected for cracks in the radius using dye penetrant, or equivalent, within the next 50 hours' time in service and repeated within each 400 hours' time in service thereafter until hinges are replaced as indicated in (b). If cracks are found, the hinges must be replaced prior to further pressurized flight.

(b) Aircraft with hinges having less than a 1-inch door skin recess radius must have the hinges replaced within the next 2,000 hours' time in service. Parts not replaced at the end of 2,000 hours' time in service can be kept in service an additional 600 hours providing inspections per (a) are made each 200 hours' time in service.

(c) All replacement hinges must have at least a 1-inch door skin recess radius and hinges having a 3/32-inch radius may not be reworked to the 1-inch radius.

(d) Upon request of the operator, an FAA maintenance inspector, subject to prior approval of the Chief, Engineering and Manufacturing Branch, FAA Western Region, may adjust the repetitive inspection intervals specified in this AD to permit compliance at an established inspection period of the operator if the request contains substantiating data to justify the increase for such operator.

(e) Aircraft modified for unpressurized operations by a modification approved by the Chief, Aircraft Engineering Division, FAA Western Region, and in which the initial inspections required by paragraphs (a), (b), (c) or (d) of this AD have been accomplished, may substitute the following in lieu of the use of a dye penetrant in accomplishing the inspections required by paragraphs (a), (b) (c), or (d):

1. At intervals not to exceed 200 hours' time in service, perform a visual inspection of all emergency exit door hinges and door skin recesses for cracks in accordance with an FAA approved maintenance program.

2. This adjusted inspection requirement does not void the requirement to replace the hinges in accordance with paragraph (b).

3. Restoration of the cabin pressurization system to operational status negates the relief provided by paragraph (e).

(f) Equivalent inspection procedures and repairs may be used when approved by the Chief, Aircraft Engineering Division,FAA Western Region.

(g) Special flight permits may be issued in accordance with FAR 21.197 and 21.199 to operate airplanes without differential pressure, to a base for the accomplishment of inspections required by this AD.

(Douglas Service Bulletins DC-6 No. 848; second reissue dated January 4, 1961, and DC-7 No. 393 dated January 3, 1961, cover the above subject.)

Amendment 259 supersedes AD 54-25-01.

This directive was effective March 15, 1961.

Revised January 18, 1962.

This amendment 39-3354 becomes effective December 1, 1978.