Originally Posted by
Shaggy Sheep Driver
They must have had hydraulics and some electrical power as they lowered the gear and were able to use the radio.
Would they be able to lower the gear (apparently normally as can be heard on the ATC recording ["gear down"], not by use of an emergency procedure) with no engines running to provide hydraulic power?
Battery power is enough for the radio. Comm 1 and Nav 1 are powered off the battery. Hydraulics is not required to lower the gear, gravity will do the job, however there is a DC pump powered by the battery that will provide enough hydraulics to fully extend the main gear if necessary. It is only used if greens are not achieved initially. Also the normal gear selector is not available at the emergency power level and so the emergency gear down lever needs to be used. That said, calling for "gear down" rather than a checklist procedure is not an unreasonable thing to do given that he was probably under a lot of stress at the time. He had maybe either forgotten that the normal selector won't work or he expected the FO to know enough to get the gear down using the emergency system.