Bis47, you have a very jaundiced view of manufacturers.
In addition to the test pilots, most manufacturers have many training Captains, highly experienced in airline operations. Furthermore, many operators (flight and ground crews) will participate in the final certification flight trials involving workload, reliability, and ‘operability’
To design and build a successful aircraft the manufacturer must have a sound grasp of the market, which is normally centered on safe as well as economic operations.
The manufacturer’s initial checklists are approved by the certification agency; operators may change these with the regulatory authority’s approval (no technical objection), but normally the operator is referred to the manufacturer as the content and order of checks may have been chosen to meet certification requirements, e.g. frequency of first flight checks vs forecast system reliability.
If, as is possible in this accident, the reliability of a system is questioned, then the frequency or order of a check can be changed. However, the manufacturer and certification authority has to ensure that no new problems are introduced by the change, e.g. if crews should check the config warning system (test the horn) before each fight in addition to the pre take of config check (no horn), what are the safe guards against crews becoming so familiar with hearing a horn they mistake it as the normal condition where there is actually a failure.
Many might argue that this ‘could not’ happen – it wouldn’t happen to me … (the old view of human error). However, the same might be said for the probability of taking-off without flaps, either due to both crew members suffering error and/or a system failure; checklists are designed to prevent this, to achieve safety in proportion to the risk of introducing other problems.
If a major contribution to this accident is human error, then the investigation needs to look deeper for the reasons why the human(s) suffered error. What is the frequency of system failures, how often are system faults misdiagnosed /inappropriately repaired, mal-use of MEL, and how often do crews forget to set flaps – to be caught by someone/ something - ‘last minute checks’? This is best achieved in a no blame environment.
All of us should review our normal operations – not what the SOPs say, but what we actually do, our norms / habits. Amongst these might be some examples of the defenses which achieve the required level of safety in operations, even though we face the same problems identified in this accident, i.e. what do we every day to ensure safety.
How do we identify mis-selection of flaps, how often do we detect other mistakes, and how is this achieved – we have to identify the successful ‘norms’ and the reason for them, and then if necessary, change the checks.