The number
(90 mins) actually comes from CS25 ... and now we really are getting a bit
dodgy so far as the syllabus is concerned ... but we can cope ...
They are talking about ... flights across land areas which have been designated
by the State concerned as areas in which search and rescue would be especially
difficult, they must be equipped with at least one ELT(s), pyrotechnic
signaling devices and additional survival equipment taking into account
the number of persons on board, except that the additional survival
equipment need not be carried when the aeroplane either:
.... for aeroplanes certificated to JAR-25 or equivalent, no greater distance
than that corresponding to 90 minutes at cruising speed from an area suitable
for making an emergency landing.