oceancrosser

Tried to to a search on this subject but little came up.


I am curious about Airbus 318/319/320/321 ETOPS certification, I know that they are approved for 180 min, but what I want to know is in what way systems redundancy is provided, mainly for hydraulics and electrics. Is there a Hydraulic Motor Generator, or a Ram Air Turbine? If not how is redundancy achieved? Is the APU supposed to start even when "cold-soaked"

Thanks,

clark y

Oceancrosser,

Yes, the A320's etc have a Ram air turbine connected to one of three hydraulic systems. There are 2 engine driven systems (1 each side) plus an electric centre system which has a ram air turbine (RAT) attached as a backup. The RAT can also work as an electric generator if your other electrics are broken, provide the centre hydraulics are O.K. With the APU, it does have requirements with respect to cold soaking. In the company I work for it is quite common to have maintenance requirements to do in flight starts of the APU for quality assurance. This requires the APU to be started after 2 hrs of cruise flight and the results noted. Also my company only has 120 minutes ETOPs.

Other stuff for ETOPs include fire suppresion and maintenance and component tracking for ETOPs critical parts.