RE: HarryMann (#3774)
These things are figured out from detailed consultation of test-flight crew/flight-test engineers
Actually, these things are governed by airworthiness requirements, e.g.:
FAR/JAR 25.207 Stall warning (a)Stall warning with sufficient margin to prevent inadvertent stalling (...) must be clear and distinctive to the pilot in straight and turning flight.
Subparagraphs (b) through (f) of this section define the required margin in more detail.
regards,
HN39