March 13, 2019

expert reaction to some countries grounding the Boeing 737 Max aircraft following the Ethiopian Airlines crash

Reactions to some countries grounding the Boeing 737 Max aircraft.

Dr Thurai Rahulan, Senior Lecturer in Aeronautics, University of Salford, said:

“After extensive testing, the 737 MAX entered passenger service about two months after gaining certification from the FAA and EASA in March 2017.  Every one of the 350 that had been delivered to airlines all over the world so far conducted regular commercial flights with a good safety record.

“Based on the limited information gleaned so far from the two accidents, banning the 737 MAX by a number of countries as a precautionary measure seems excessive at this stage.

“The sensor in question is the angle-of-attack indicator which may have transmitted erroneous data to the controller which issues command signals to the variable incidence tailplane actuator to prevent an aerodynamic stall.  In case of an encounter with such type of a runaway stabiliser condition, all pilots should be familiar with the procedure to disengage the system and effect a recovery manoeuvre.  As a result of lessons learned from un-commanded control surface deflection events over the past few decades, modifications were made to improve safety.

“Since very little is known about the cause(s) of the two recent crashes, we shouldn’t jump to conclusions until the air accident investigators from many agencies, including the manufacturer, issue the first set of firm findings.  Studies to further improve safety and understanding of these systems by the operators are being undertaken by the aircraft manufacturer.”

Declared interests

None received.