55-04-01: Wheel Skis

55-04-01 FEDERAL SKIS: Applies to All Cessna Model 180 Aircraft Equipped With Federal Model AWB-2500A Wheel Skis. Compliance required as soon as possible but no later than next 100 hour inspection. Instances have been reported of the main skis pitching downward against the forward limiting cables during normal flight causing the airplane to assume a dive attitude with a resulting loss of altitude before recovery. To preclude the possibility of the serious consequences that might result should this condition occur at low altitudes, the following corrective action must be accomplished: 1. Replace the existing mechanical rigger with Federal No. 11G1064-2 mechanical rigger. 2. Install Federal No. 11D1059-5 preloaded bungee assembly in each of forward limiting cables and adjust the cables so that the skis when in the "up" position on the wheel, will be allowed to pitch nose down minus 12 degrees to 14 degrees in flight without extending the bungee units. This angleis measured between the top of the ski channel and the horizontal reference line of the airplane. (Federal Service bulletin No. 102 covers the same subject.)