A wing of the Boeing 737 MAX at the Boeing plant in Renton, Washington. Picture: REUTERS/MATT MILLS McKNIGHT
A wing of the Boeing 737 MAX at the Boeing plant in Renton, Washington. Picture: REUTERS/MATT MILLS McKNIGHT

Boeing says it has developed a new flight-control software update to provide additional layers of protection for its controversial fire 737 MAX 8 airplanes.

The American manufacturer has been reeling following two deadly crashes involving the planes, which have shaken confidence in the aircraft seen as crucial to Boeing’s future plans.

One of the models in operation in SA was grounded after an Ethiopian Airlines MAX 8 crashed in Nairobi, Kenya earlier in March, killing all 157 people on board. The crash came after a Lion Air jet of the same model crashed in Indonesia late in 2018, killing all 189 people on board. Following the crashes, Boeing shares plummeted wiping billions of dollars off the manufacturer’s market value.

JSE-listed airline Comair relented to public pressure and decided to stop using its MAX 8 aircraft after the fatal Ethiopia crash.  Other airlines have also grounded their MAX 8s. 

The SA airline, which operates the British Airways brand locally, said it had taken the decision even though it remains confident about the “inherent safety” of the plane. It has decided temporarily not to schedule the aircraft, while it consults other operators, Boeing and technical experts.

“The safety and confidence of our customers and crew is always our priority,” Wrenelle Stander, executive director of Comair’s airline division, said in a statement earlier in March.

While investigators have yet to make a link between the Ethiopian Airlines crash and an accident in Jakarta in October 2018, carriers in China, the Cayman Islands and Indonesia have decided to ground the aircraft. The MAX 8 was grounded in the US on March 13. The aircraft’s anti-stall software is suspected to be the cause of the two crashes.

The MAX 8 is the fastest-selling aircraft in Boeing’s history with roughly 370 delivered so far and some 4,700 more on order, Al Jazeera reported on Wednesday. Some airlines have said they are re-evaluating existing orders of the MAX 8 in the wake of the crashes.

In a press briefing in the US on Wednesday, Boeing senior managers said the “manoeuvring characteristics augmentation system (MCAS)” flight-control law was designed and certified for the model to enhance the pitch stability of the airplane so that it feels and flies like other 737s.

“MCAS is designed to activate in manual flight, with the airplane’s flaps up, at an elevated angle of attack (AOA). Boeing has developed an MCAS software update to provide additional layers of protection if the AOA sensors provide erroneous data. The software was put through hundreds of hours of analysis, laboratory testing, verification in a simulator and two test flights, including an in-flight certification test with US Federal Aviation Administration (FAA) representatives on board as observers,” Boeing said.

The additional layers of protection include a flight-control system that now compares inputs from both AOA sensors. If the sensors disagree by 5.5 degrees or more with the flaps retracted, MCAS will not activate. Furthermore, an indicator on the flight deck display will alert the pilots, according to Boeing.

Said Boeing officials: “We continue to work with the FAA and other regulatory agencies on the certification of the software update.” 

With Linda Ensor

phakathib@businesslive.co.za