updated designs that meet the certification criteria at the time is valid.
The cost of a clean sheet design, versus a supplementary type certificate for an updated design, makes operational and commercial sense.
As it did to Boeing but it was the commercial imperative that overrode any operational sense.
T
he first is how the organisational culture of Boeing had changed over the years since it acquired McDonnell Douglas, a failing aerospace contractor, in 1997. Boeing’s organisational culture is now radically different from its old engineering-led ethos. It’s now run by a board that seems driven more by marketers than by engineers – which may explain why it pressed for the Max not be be treated as a new aircraft (requiring thorough – and expensive – re-certification by the FAA) but merely as a modification.
From one of the many articles written on the subject. It certainly was cheaper to revamp the 737 rather than start with a clean sheet of paper but at what cost?