Pilot error … Automation Dependency or Pilot Dependency
‘it is not required for certification’; correct, but any installed system has to operate as intended (described, trained for, and operational expectation), and must enable the crew to manage errors resulting from interactions that can be reasonably expected in service. CS25.1302 and CS AMC.1302, which is one of the few requirements where the FAA and EASA did not initially use similar (same) text; however both the FAA and Boeing were significant contributors to the drafting of CS25.1302
‘… qualified flight-crew members trained in its use can safely perform their tasks associated with its intended function by meeting the following requirements:
… enable flight crew awareness, if awareness is required for safe operation, of the effects on the aeroplane or systems resulting from flight crew actions.
Operationally-relevant behaviour of the installed equipment must be:
Predictable and unambiguous, and
Designed to enable the flight crew to intervene in a manner appropriate to the task.
To the extent practicable, installed equipment must enable the flight crew to manage errors resulting from the kinds of flight crew interactions with the equipment that can be reasonably expected in service, assuming the flight crew is acting in good faith.’
Thus as much as some posts wish to cite pilot error, consider where the error originated?
The NTSB’s Probable Cause wording has been chosen carefully. Although aspects of the flight were mismanaged there is no explanation of how or why the automatic speed system was ‘unintentionally deactivated’ – unintentional is one view of error. Neither is there any consideration of the airspeed display being adequate for monitoring in these circumstances – cf many other poor speed awareness incidents.
The references to system description and training bias judgement of CS25.1302 in this accident towards the expectation that will pilots are expected to detect errors (cf other 777 incidents). This pilot dependency could a significant problem where automation is assumed to reduced training requirements, - less ability to detect error, reduced system knowledge / experience, and particularly so where automation is used in increasing complex operational environments.
The alternative interpretation is that manufacturers and regulators (and the industry at large) should improve equipment tolerance to error and balance the assumptions made about crew interface with automation in the changing operational and social environment; this assumes that automation weaknesses cannot be rectified in a suitable timescale.
The issue here is the balanced judgement of the requirements, who makes the judgement, what assumptions are in the judgement, and if these assumptions are published for operator / crew awareness.