I presume you are talking about the fake unload on Revenge of the Mummy. It's part of the ride itself and, without wanting to spoil it for those who haven't done it, it is a part of the ride where the ride comes to a standstill and you are led to believe the ride is finished. However, you don't disembark and then there is more to the ride after that - hence 'fake unload'
Hope I've explained that OK - didn't want to ruin the ride for those who haven't seen it yet