A Boeing 737 while flying from Karachi to Doha on 3ʳᵈ September 2006 experienced severe vibration. The aircrew reported that vibrations were so severe that a number of instrument bubbled out from their position in the instrument panels. On landing it was found that a portion of right elevator had broken and flown during the flight. The aircraft documents showed that this aircraft was experiencing severe vibrations for last one week; aircrew had been making serious observations; the second last states "aircraft is unserviceable", however the ground crew was declaring aircraft fit for service after every aircrew reported defect of vibrations, in a routine manner. And this has not been first case. The incident could have been disastrous if the cracks which have developed on stabilizer due to vibrations propagated further and resulted into structural failure of right hand stabilizer. The elevator was dispatched to Boeing Company for material analysis. The investigations have indicated that non professionalism to rectify vibrations on part of maintenance crew and ineffective monitoring of serious repeat vibration defects by Quality Control System resulted into occurrence. PIA Management has already taken administrative actions against the persons involved in improper technical rectifications.
