COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES Cessna 400 Series Aeroplanes AD/CESSNA 400/34 Auxiliary Fuel Cells - Inspection and Replacement 6/72 Applicability: All Model 411 with S/Nos. 411-0001 to 411-0300 and Model 421 with S/Nos. 421- 0001 to 421B-0048 fitted with Uniroyal Type US-932 or Goodyear Type BTC-39 Auxiliary Fuel Cells or any subsequent numbered aeroplanes which have been fitted with the above fuel cells as a replacement. Requirement: 1. Uniroyal Auxiliary Fuel Cell Type US-932 1.1 Before each flight inspect the external lower surface of the wings for evidence of fuel leakage. Pay particular attention to rivet heads, inspection covers and skin lap joints. Defective fuel cells shall be replaced with Goodyear Type BTC-54A fuel cells before further flight. 1.2 Within 300 hours time in service or 6 months after 28 June 1972 whichever occurs first, the Uniroyal Type US-932 fuel cells shall be replaced by Goodyear Type BTC-54A fuel cells. 2. Goodyear Auxiliary Fuel Cell Type BTC-39 2.1 Before each flight inspect the external lower surface of the wings for evidence of fuel leakage. Pay particular attention to rivet heads, inspection covers and skin lap joints. Defective fuel cells shall be replaced with Goodyear Type BTC-54A fuel cells before further flight. Note 1: A pilot endorsed for the type may perform and certify for this inspection as detailed in paras. 1.1 and 2.1. Note 2: The repetitive inspections required by paras. 1.1 and 2.1 may be substituted by the normal daily inspection when Goodyear BTC-54A cells are installed. Compliance: As detailed in requirement document.