The Australian Transport Safety Bureau is investigating Jetstar over two safety incidents that had the potential to affect flight safety.

On the 19th October 2015 a scheduled flight to Melbourne, operated by Jetstar departed from Brisbane with sixteen more passengers than had been accounted for in the crew’s flight plan. Ten days later a flight from Melbourne to Perth took-off outside its permitted loading limits for take-off and landing. The Air Transport Safety Bureau (ATSB) has commenced an investigation into what it considers to be serious safety incidents that had the potential to affect aircraft stability and flight safety.

Aircraft stability and flight safety depend on the position of an aircraft’s centre of gravity during all phases of flight, including take-off and landing. The centre of gravity is the point where an aircraft would balance if it were placed on a fulcrum. An aircraft’s centre of gravity must remain within certain limits to ensure stability and structural integrity whilst it manoeuvres in accordance with its approved flight manual. Flight safety also depends on an aircraft not exceeding its maximum permitted take-off and landing weights.

The first incident occurred on the 19th October 2015 and involved an Airbus A320 flying from Brisbane to Melbourne. During the boarding process the flight crew were advised of a discrepancy at check-in that involved twelve passengers. A little later the flight crew were advised that the discrepancy had been resolved and they were given the final passenger numbers to complete their load and balance calculations. During the flight the flight crew requested that the cabin crew perform a passenger count. The count indicated that the aircraft had departed with sixteen more passengers than advised increasing the landing weight by about thirteen hundred kilograms. The flight crew recalculated their landing data before they commenced their descent into Melbourne.

The second more serious safety incident occurred ten days later on the 29th October 2015. This incident involved an Airbus A321 flying from Melbourne to Perth. During take-off the pilot noticed that the aircraft was nose heavy during rotation. Once airborne the flight crew requested that the cabin crew confirm the passenger numbers and seating arrangements. The flight crew re-entered the passenger data into the flight management system. The aircraft was found to be outside its permitted loading limits for take-off and landing. Some passengers were moved in the cabin to ensure that the aircraft landed within its permitted limits.

It was fortunate that the second incident was not more serious. Had the extra passengers shifted the centre of gravity aft beyond its limit, the aircraft could have lost pitch control during take-off. This was a contributory factor to a fatal accident in 2003 when an Air Midwest Beechcraft 1900D crashed, destroying the aircraft and killing all on board.

Until the final report is published next year, we cannot say for certain what happened but the ATSB investigation will uncover systemic errors in Jetstar’s flight operations.

Jetstar has already reacted to these safety incidents and implemented an interim procedure. Once the cabin door is closed, a cabin crew member uses a tally counter to count all passengers. The tally is checked with the load data provided to the flight crew. It remains to be seen whether this interim measure becomes permanent. That depends on whether Jetstar adopt a reactive or systemic or approach to problem solving.