The Malta Independent 16 December 2019, Monday

Airbus A320neos subject to airworthiness directive for ‘potentially unsafe’ centre of gravity issue

Albert Galea Sunday, 29 September 2019, 09:30 Last update: about 4 months ago

The Airbus A320neo – of which Air Malta currently has three –  has become the subject of an airworthiness directive issued by the European Union Aviation Safety Agency (EASA) following the finding of an issue with the aircraft’s centre of gravity envelope.

The issue, while described by the EASA as being “potentially unsafe”, has never been encountered during operations, but was deemed serious enough by the EASA to warrant a directive being issued to solve it.

The directive was issued on 31 July 2019 and became effective on 14 August 2019.

“Analysis and laboratory testing of the behaviour of the flight control laws of the A320neo identified a reduced efficiency of the angle of attack protection when the aeroplane is set in certain flight configurations and in combination with specific manoeuvres commanded by the flight crew”, the directive read.

“This condition, although never encountered during operations, if not corrected, could lead to excessive pitch attitude, possibly resulting in increased flight crew workload”, it said.

As a result of the directive, Airbus has restricted the centre of gravity envelope with an Aircraft Flight Manual Temporary Revision in such a manner that it will prevent the aforementioned condition from arriving.

In simple terms, the centre of gravity of an aircraft is an average of where its weight is located. If more weight is placed at the front of the aircraft, the centre of gravity will move forward, and if the weight moves towards the back of the aircraft, the centre of gravity then moves with it.

Depending on where the centre of gravity is located, changing it could have an effect on the aircraft’s handling. As such, aircraft manufacturers produce what is called an “envelope” of the acceptable centre of gravity. If the centre of gravity exits this envelope, the aircraft may then not handle as expected. 

The directive applies to Airbus A320neo aircraft – more specifically the A320-251N, A320-253N, A320-271N and A320-273N models.

Air Malta is one of 51 airlines across the globe which utilises this aircraft, and has three Airbus A320-251Ns in its fleet – 9H-NEO, 9H-NEB, and 9H-NEC. The first was delivered to the airline in June 2018, the second was delivered in July 2019, and the third was delivered two weeks ago, on 12 September 2019.

However, questions sent by this newsroom to the national air carrier over a week ago asking what precautions had been taken as a result of the EASA’s directive and whether the directive would in any way affect future orders of the aircraft remained unanswered at the time of writing.

Currently, including the three aforementioned new aircraft, Air Malta has a fleet of 11 aircraft.  Besides the new aircraft, the airline operates seven Airbus A320-200s and one Airbus A319.

The national carrier last year began embarking on a plan which will, by 2022, see its fleet fully replaced by A320neos.

While it is as of yet unclear what precautions the national carrier took, international media has reported that other airlines have employed various mitigation measures to deal with the issue, with the most common being to block off the last row of seats on the aircraft from being booked.

In fact, Lufthansa – which currently operates 20 A320neos – have blocked off the back row of the aircraft as a precaution, while British Airways have also done the same thing due to the this directive. Budget airline EasyJet meanwhile, according to The Daily Mail, have elected to change the way it loads luggage onto the plane rather than blocking off the last row of seats.

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