Gear extension with dual engine failure
 

Hi,

I saw a video with dual engine failure after takeoff at 2500feet and an immediate return to the runway. The gear was retracted directly after takeoff and then extended (not gravity extended!) shortly before the landing. The APU was never started and only the rat was powering hydraulics and electric systems.
In another video however I watched a dual engine failure at 7000 feet. In this video however the youtuber mentioned that you definetely need to activate the APU in order to power the yellow hydraulic system that will give you the ability to extend gear and flaps via the green system when using PTU. I also tried this in the simulator and noticed that with only the blue hydraulics I was not able to extend the gear normally as the youtuber said.
But how was the pilot in the first video able to extend the gear? '

Thanks!

Best regards Andi

The engines windmill and during that windmill actually still generate hydraulic power, which could be enough to extend the gear, but it is not nearly guaranteed to work. Dunno about other airlines, we have an Emergency Landing (all engine failure) checklist on the back of our normal checklist, which does call for gravity extension of the landing gear. That checklist is meant for the first you cite, complete loss of thrust close to the ground. I'm pretty sure it is a company procedure, not an airbus one, we did not have that in a previous airline i flew for that was on 100% airbus procedures.