Final Report


At about 1250 pm Eastern Standard Time, the regular public transport Cessna 208 approached Townsville Airport, Queensland. On board were the pilot and eight passengers.

Shortly after passing the final approach fix on the runway 07 area navigation (RNAV) approach and transitioning into visual conditions the pilot configured the aircraft for final approach and landing.

As the pilot selected the third and final stage of flap, a muffled bang was heard coming from outside the aircraft and the aircraft banked violently and rapidly to the left. The pilot immediately attempted to regain control and applied opposite aileron. However, the aircraft continued to bank even more steeply to the left with the subsequent secondary effect of aerodynamic yaw to the left.

Descending through about 700 ft, and with the aircraft now travelling at about 45° the runway, and still not responding, the pilot applied full right rudder. There was some response from the aircraft to this input, but it was still not under control. The pilot then retracted the flap one stage, back to 20°. From here the pilot was able to regain sufficient control to steer the aircraft back toward the runway and land without incident.

A post incident engineering inspection revealed that a bolt from the aft inner bellcrank had worked loose and was missing.

After further detailed inspection the company found that the manufacturer’s inspection schedule in regard to the flap mechanism, although being complied with, was inadequate for their needs. The company have amended their maintenance schedule to include full inspections and life limitations to other structures in the flap mechanism.


Aviation Short Investigations Bulletin - Issue 48

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