The 320 FCTM states very clearly that a dual hydraulic failure is a MAYDAY and that you should land ASAP (in red)
Holding next to a suitable runway for the purpose of reducing weight, with this failure, is a mugs game, end of.
If you have a pressure differential between the green and yellow system of 500psi the PTU will run. If this is due to fluid loss then the good system will overheat running the PTU and so will also go down. That's why the 1st action on ECAM for green or yellow overheats, loss of fluid etc is to switch the PTU off thus preventing the loss of the 2nd system.
Snag is one of the main times you will lose the green system fluid is on gear retraction after t/o. Depending on your mod state you may not know this until your above 1500' aal due to take off inhibit restricting the warnings that come up. At that stage it may well be too late to prevent the 2nd system from failing due to an overheat. However you will get it back once it has cooled and once you've switched the PTU off it will work fine so your back to 2 systems. This may well be what occurred in this instance and if so holding to burn fuel would be fine as you only have a single failure. In fact depending on the destination continueing may be fine too.
Airbus have a mod out to prevent the after take off gotcha but I guess not all will have it?
Last edited by Ashling; 22nd Jun 2012 at 01:46.