Functional Checks
Functional checks are error capturing mechanisms in some instances since they will detect, if properly actioned, if something is not installed, secured properly, adjusted correctly or meets specified criteria in the manuals. This is true for most systems and is an inherent part of the maintenance process. It is, in the majority of cases, impossible to carry out a duplicate inspection on a flying control without a function check since the range of movement, control stop clearances, control system friction or loading checks cannot be determined otherwise. The problem is that since they are regarded as an inherent part of the system, complacency can set in concerning their purpose and value. It is only when the function checks or ground runs are not carried out and an incident occurs, (e.g. double engine oil loss on a 737-400 at Daventry) that their ...