Verticalflight: what is your interest for? Is it to satisfy the CAA and/ or customer for a new operation....or is it to reduce downtime between sorties?
My experience of Offshore HUMS downloads was after every flight, where practical, and definitely everyday as a minimum.
MEL limitation for u/s HUMS system was 25 flying hrs....as long as there was no reduced intervals in place for existing threshold exceedances.
A 'red' threshold exceedance grounded the a/c until investigated by engineering.
An 'amber' threshold exceedance initiated a reduced download interval of max 3-10 flying hrs depending on what system the threshold was for.
Last edited by nodrama; 14th Jan 2009 at 14:16.