There is an uncomfortable aspect of the Ethiopian Airlines Boeing 737 Max accident that complicates an investigation whose narrative has been dictated by debate over the controversial Manoeuvring Characteristics Augmentation System.
While Boeing has faced a public avalanche of scorn and scepticism – perhaps deservedly – the accident sequence does not easily divide into convenient ‘before’ and ‘after’ timelines, separated by a well-defined point, some 1min 21s into the flight, when MCAS wrote its trace onto the flight-data recorder like a harbinger of catastrophe.
This boundary has instead been blurred by preliminary findings that raise awkward questions about airmanship and training, ones which are unlikely to sit easily with those who would prefer blame to be an exclusively external, rather than internal, affair.
Ethiopian Airlines has claimed its pilots were well-briefed on the Lion Air 737 Max accident which occurred less than five months earlier.
But the Ethiopian inquiry has not indicated whether either pilot recognised critical warning signs that emerged immediately after take-off, such as the one-sided stick-shaker and disagreeing instruments, or made a connection over the behavioural similarities with the ill-fated Lion jet.
Procedures for unreliable airspeed indications typically require the autopilot and autothrottle to be disengaged. But the crew persisted with activating the autopilot on the unreliable side, proceeding with an intended climb to cruise altitude – apparently selecting 32,000ft rather than the cleared 34,000ft – and leaving the thrust at the take-off, rather than climb, setting. Despite the continuing stick-shaker activation, the flaps were retracted.
Context is everything, of course, and the inquiry has months to run before a full explanation emerges. It has not yet released a full cockpit-voice recorder transcript.
But the impression is less that of a well-conducted flight interrupted by a software system gone rogue, than an escalation of small problems into a major one.
Unforeseen consequences of advanced technology are almost inevitable. Airbus has not been immune to anomalies arising from that most basic of computer laws: garbage in, garbage out.
Boeing unveiled the 737 Max exactly 100 years after the poet Rudyard Kipling warned that machines were “not built to comprehend a lie” and would neither “pity nor forgive” mistakes in handling them.
Which is why procedural discipline and airmanship, built on a foundation of training and experience and comprehension, are essential core qualities. To question whether the 737 Max is ‘safe’ is to misunderstand the fundamental interrelations of all the components which contribute to air transport safety.
In an industry where aircraft are certified at the hands of seasoned test pilots but delivered to operators whose own crews are not necessarily as skilled in expecting the unexpected, investigators will face pressure to judge not just whether MCAS is suitable in its own right but whether any perceived problem with the 737 Max might be a reflection on the training and capabilities of those in the cockpit.
Source: Cirium Dashboard
