80-09-08 R2 FAIRCHILD AIRCRAFT CORP. (Swearingen): Amendment 39-3758 as amended by amendment 39-3883 is further amended by amendment 39-5821. Applies to Models SA 226-TC (S/N TC201 through TC419) and SA 226-AT (S/N AT001 through AT074) certificated in any category. Compliance required before pressurized flight or prior to obtaining 250 unpressurized flight hours after compliance with emergency telegraphic AD T80SW14 dated March 15, 1980, amended.
To assure proper adjustment, operation, and structural integrity of the cargo door latching mechanism, accomplish the following:
(a) With the cargo door open, conduct the following inspection to assure full expansion of the click-clack latch jaws. Move the door handle to the door closed position. Using a "go, no-go" type of gage, determine that the distance from the inside of the click-clack plunger face to the edge of the click-clack jaws is not less than 0.34 inches. Adjust each latch as necessary to gain a minimum of 0.34 inches by varying the length of its connecting push-pull rod.
(b) To assure proper engagement of the click-clack jaws into the door frame receptacle, three measurements are necessary. The first measurement (door open) is the dimension from the door face plate surface to the undercut on the click-clack jaws. The second measurement (door open) is the dimension from the door frame receptacle face plate surface to the jaws seating surface. The third measurement (door closed) is the gap (taken with a feeler gage) between the surface of the door frame receptacle and the door face plate surface. The first dimension must be at least the sum of the second and third dimensions to assure proper engagement of the click-clack jaws in the door frame receptacle. Adjust each latch as necessary to gain the proper click-clack engagement by varying the length of its connecting push-pull rod.
(c) Inspect each door face plate and receptacle face plate for evidence of deformation. If deformed, also inspect door frame and door latch assembly for evidence of cracks or deformation. If such defects are detected, replace with airworthy part.
(d) Using an inside micrometer, or equivalent, measure the inside diameter of each receptacle. Measure across the hole in at least three directions to check for roundness. The widest dimension must be used to compare with the following allowables.
(1) Receptacles on side of cargo door, one piece type, limit 0.690 inches.
(2) Receptacles on side of cargo door, eccentric type, limit 0.700 inches.
(3) Receptacles on bottom of cargo door, one piece type, limit 0.670 inches.
(4) If any receptacle is oversized, replace with an airworthy part.
(e) Check the cargo door warning system as follows:
(1) With the door in the open position, manually depress all door warning switches. Check to see that the cargo door warning light in the annunciator panel is extinguished.
(2) Selectively release and depress each warning switch. Check that with all other switches depressed, releasing any individual switch causes illumination of the cargo door warning light. Actuate each switch several times while checking for any tendency for the switch to stick in the depressed position.
(3) Any switches that show any tendency to stick in the depressed position should be replaced.
(f) After the inspections and adjustments required by paragraphs (a) through (e) have been satisfactorily completed, open and close the cargo door a minimum of three cycles.
(1) Operate the door handle to the closed position during each door closed cycle.
(2) Door open light on annunciator panel must be out when door is closed. (Reference Swearingen SA226 series maintenance manual for proper switch adjustment.)
(3) If the door mechanism or warning light system does not function properly during the three open and close cycles, reconduct inspections and adjustments as described above.
(g) Repeat the steps as necessary until the cargo door operates properly.
(h) Repeat the inspections and adjustments required by paragraph (a) through (g) of this AD as follows:
(1) Each 1,200 flight hours for airplanes which have been modified per Fairchild SB 226-52-008 revised April 6, 1984, or
(2) Each 250 flight hours for airplanes that have not been modified per the above SB.
(i) Special flight permits may be issued in accordance with FAR 21.197 and 21.199 to operate airplanes unpressurized to a base where the inspections and adjustments can be accomplished.
(j) An equivalent means of compliance with this AD may be used if approved by the Manager, Airplane Certification Branch, Southwest Regional Office, FAA, Fort Worth, Texas 76193-0150; Telephone (817) 624-5150.
All persons affected by this AD may obtain copies of the document(s) referred to herein upon request to Fairchild Aircraft Corporation, P.O. Box 790490, San Antonio, Texas 78279- 0490; or mayexamine the document(s) referred to herein at FAA, Office of the Regional Counsel, Room 1558, 601 East 12th Street, Kansas City, Missouri 64106.
Amendment 39-3758 became effective May 14, 1980 and was effective to all recipients of telegraphic AD T80-SW-15 dated March 20, 1980.
Amendment 39-3883 became effective August 26, 1980.
This amendment 39-5821 revises AD 80-09-08 R1, Amendment 39-3883 (45 FR 56333; August 25, 1980).
This amendment 39-5821 becomes effective on February 5, 1988.