74-20-01 CESSNA: Amendment 39-1966. Applies to Models 310Q (Serial Numbers 1038 through 1069, 1071 through 1081, 1083 through 1086, 1088 through 1105, 1107, 1109, 1110, 1112, 1113, 1115 through 1118, 1122, 1123, 1125 and 1126); Model 340 (Serial Numbers 0325 through 0354); Model 402B (Serial Numbers 0575 through 0581, 0583 through 0586, 0588, 0590 through 0611, 0613, 0614 and 0617); Model 414 (Serial Numbers 0503 through 0529, 0531 and 0532); and Model 421B (Serial Numbers 0322, 0584 through 0625, 0627, 0629 through 0633, 0635 and 0636) airplanes.
Compliance: Required as indicated, unless already accomplished.
To preclude possible main landing gear trunnion failure, accomplish the following:
A) Within 25 hours' time in service after the effective date of this AD, visually inspect the LH and RH main landing gear assembly to determine whether the landing gear assembly serial numbers fall within the following serial number blocks:
Aircraft Models Affected
Main Landing Gear Assembly Serials Affected
L/H
R/H
Model 310Q
B170 thru B279
W146 thru W273
Model 340
B199 thru B345
B164 thru B330
Model 402B
B199 thru B345
B164 thru B330
Model 414
B199 thru B345
B164 thru B330
Model 421B
W108 thru W185
W090 thru W170
If a main landing gear assembly falls within the above serial number blocks, visually inspect the trunnions for cracks or forming flaws in accordance with Cessna Service Letter ME74-14 dated August 9, 1974, or subsequent revisions. Repeat these inspections at intervals of 25 hours' time in service thereafter until the trunnions are replaced.
B) If cracks or forming flaws are found during any inspection required by Paragraph A, prior to further flight, replace the main landing gear upper strut with an airworthy part in accordance with Cessna Service Kit 421-63.
C) Within 100 hours' time in service after the effective date of this AD, replace main landing gear upper strut assemblies of the serial numbers listed in Paragraph A with an airworthy part in accordance with Cessna Service Kit 421-63.
D) The inspections required by this AD may be discontinued upon replacement of the affected main landing gear upper strut assemblies.
E) Any equivalent method of compliance with this AD must be approved by the Chief, Engineering and Manufacturing Branch, FAA, Central Region.
This amendment becomes effective September 25, 1974.