Examination of the landing gear revealed that the right wheel could be extended normally but that the left wheel could not be lowered. Inspection showed that when last retracted, the axle of the left wheel had missed the stop provided in the wheel-well and had gone further into the well than its normal position. The wheel was so tightly wedged into the wheel-well that only after removing approximately one inch of the stop cashing by use of a hack-saw could the gear be lowered.
It was also noted that the left wheel shock struts were not fully extended but were approximately half deflected, or about in the same position as when the airplane is on the ground. With the struts in this position the wheel axle did not retract against the stop in the wheel-well but passed in front of it. This resulted in the wedged position of the left side of the landing gear.
Disassembly of the left shock struts revealed that the inboard strut was free and operating normally, but that the outboard strut was seized. During disassembly it was found exceedingly difficult to remove the packing nut. An examination of this strut indicated that at some previous time the packing nut had been adjusted too tightly, as a result of which the shock strut remained in a deflected position after take-off from Shreveport, Louisiana.
Investigation disclosed that the stop provided in the wheel-well is not of sufficient length to perform its function unless the shock strut is fully extended, and the Safety Bureau of the Civil Aeronautics Board has brought this fact to the attention of the staff of the Civil Aeronautics Administration. It was suggested that consideration be given to the advisability of extending the steps in the whee- wells two inches forward on this particular model aircraft to prevent the locking of the landing gear in the event of failure of the shock absorbers to extend fully prior to retraction of the landing gear. Following the investigation, the manufacturer took prompt steps to correct this defect, and the necessary alterations were approved by the Administrator of Civil Aeronautics. The maintenance problem, as reflected by the badly adjusted packing nut, also was brought to the attention of the Civil Aeronautics Administration.
BY THE BOARD
/s/ Darwin Charles Brown
Secretary
