I would be very interested in the answer to this. As a trainer on ramp activities we have been told a number of times about the damage to 747 door seals causing leakage of air into the holds thus increasing the fire risk. I have also been told that cargo holds are pressurised but not to the same level as the pax cabin. This cannot always be the case as live animals are carried in the holds. L
ets hear from an expert. Thanks