A350 Emergency Bulletin

EASA has issued an emergency bulletin and is in the process of altering the master MEL for the A350-900. The aircraft was designed with a hydraulic fluid cooling system in the fuel tanks. Tests have shown that under an overheat failure mode of the pump, the hydraulic fluid in the tanks will see a rapid temperature rise.

The fear is that if the inerting system in the tank is inoperative, the rapid rise could potentially cause the fuel air mix to ignite, leading to a catastrophic explosion of the tank. The revision of the MEL turns several items related to the system into no go items and affects the hydraulic system, AC packs, and tank inerting systems.

www.flightglobal.com...

a reply to: Zaphod58

At least they published the bulletin before an incident. Imagine if this had happened in practice, it would be a year or more before we know the actual cause of the explosion. The general consensus would be that it was terrorism. Then, when the report finally does come out and says it's a mechanical fault, a lot of people wouldn't believe it.

a reply to: Zaphod58

More good news. With this and your later post about Pratt & Whitney, guess I wont be flying overseas anytime soon.

a reply to: TonyS

Just imagine if the A350 used Geared Turbofans.

a reply to: Zaphod58

Epic fail. I was just looking at the A-350 and thinking it seems to be something dreamed up to compete with the 777?

a reply to: TonyS

More the 787. Both are ultra efficient, long range aircraft, but the A350 has the added advantage of being a competitor to the 777X family as well.

a reply to: Zaphod58

I found this interesting!
en.wikipedia.org...
I can see where there would be problems, but there are also big advantages.........if it can be done correctly.

a reply to: TonyS

Great on paper, piss poor in execution.

This isn't quite as bad as it sounds although I'm a little surprised that it has become an issue worthy of an immediate AD to alter the MEL lists. Seems like the TWA 800 incident has a lot to answer for.

Its not like this system hasn't already been used successfully in the past, including by Airbus. In order to become a problem it would need a runaway overheat on the hydraulic pump sys, low fuel status in the tank, NIGS non-functional, AC packs contributing to thermal rise in the tanks, non intervention or monitoring of tank temps and hydraulic temps by the crew, no ECAM warnings, master caution or SD page messages(presumably?) and lastly an ignition source. Its possible, but frankly highly unlikely. This is either an unnecessary knee jerk by Airbus or something else is going on that they aren't talking about, possibly a combination of both. Frankly I think its much more likely to be the former with the possibility of their being an inherent problem with the pumps design. Whichever it is I wouldn't worry about the A-350, its had a far, far better run through development and service than the A-380 or its nearest analogue the 787.

a reply to: thebozeian

Aside from a few bad jokes with friends, I didn't think this was a really bad thing, it just struck me as odd that they'd put out an emergency AD and immediately change the MEL.

The jokes were funny though.