AD 73-22-01

73-22-01 CESSNA: Amendment 39-1735 as amended by Amendment 39-3215. Applies to Model 340 (S/Ns 340-0001 thru 340-0234); Model 401 (S/Ns 401-0001 thru 401-0322); Model 401A (S/Ns 401A0001 thru 401A0132); Model 401B (S/Ns 401B0001 thru 401B0300); Model 402 (S/Ns 402-0001 thru 402-0322); Model 402A (S/Ns 402A0001 thru 402A0129); Model 402B (S/Ns 402B0001 thru 402B0392); Model 411 (S/Ns 411-0001 thru 411-0250); Model 411A (S/Ns 411-0251 thru 411A0300); Model 414 (S/Ns 414-0001 thru 414-0407); Model 421 (S/Ns 421-0001 thru 421-0200); Model 421A (S/Ns 421A0001 thru 421A0158); and Model 421B (S/Ns 421B0001 thru 421B0147 and S/Ns 421B0201 thru 421B0422) airplanes. Model 421 (S/N 421-0151) airplane is excepted from the requirement for the installation of Cessna Service Kit SK421-56 so long as it complies with STC SA599CE.

Compliance: Required as indicated, unless already accomplished.

To prevent the collection of fuel in the wing leading edge area and to provide additional instructions on preflight inspections and ground or inflight fire procedures, within the next 100 hours' time in service after the effective date of this AD, accomplish the following:

Modify the wing leading edge by installing Cessna Service Kit SK 421-56 and install applicable checklist and Flight Manual revisions as specified in Cessna Service Letter ME73-5 (Supplement 1) dated September 7, 1973, or later FAA-approved revisions, or any other modification approved by the Chief, Engineering and Manufacturing Branch, FAA, Central Region.

Amendment 39-1735 became effective October 18, 1973.

This amendment 39-3215 becomes effective on May 29, 1978.