BA744 rejected take off due to hydraulic leak

[Jeroen D]

Must have been quite a leak!

http://avherald.com/h?article=4823d395&opt=0

Very little information to go by, but even so it made me wonder.

I assume that what is called here as a leak, would most likely manifest itself as low level hydraulic fluid type of alarm? As there are four independent system, I would think the likelyhood of loosing all four due to a leak is remote at best.

Apparently they aborted at 'high speed'. Not sure what that is.

If you are faced with such a situation past V1 would you still take off, irrespective with which hydraulic system was gone! I guess which hydraulic system might have some influence over the decision as different systems/capabilities are affected.

Prior to reaching V1, ie the 'high speed' regime, would you always reject the take off, for these sort of occurences?

Thanks,

Jeroen

[Britjet]

80 kts to V1...
1) Fire or fire warning (any fire, not just an engine)
2) Engine failure
3) Predictive windshear warning
4) If the aircraft is unsafe or unable to fly
5) Nothing else!

Boeing procedures....(no 5 is mine :-)
My guess would be that this wasn't "high speed".

Peter.

[IefCooreman]

There is plenty of hydraulic backup for the "flight" scenario. There is, but much less, backup for the braking scenario. Will RTO work? Will antiskid work? Will normal brakes work? Will reversers work?... So no abort, not even when you are accelerating close to but below V1.

After 80kts, you only stop for fires, engine failure, predictive windshear, or the aircraft considered unsafe to fly. That's it.

Same with tire problems. Despite the fact that many people think it's better to stop, it's very unlogical. Why use 1/3 of the runway to do a high speed reject with a "damaged" braking system, if you can safely take it in the air and come back to use 3 times that distance (full runway) to stop and at the same time give the fire brigade time to prepare and be ready for you?

[Skybird]

At 80kts, MC lights and beeper are inhibited...

If an EICAS message comes after 80kts, the beeper will only sound at 400ft...

This Boeing design was made to avoid aborting the T.O. for items such as ... Hydraulic failure...

Let's wait for the official report...

[Jeroen Hoppenbrouwers]

"Major leak", four hours to fix, then just fly away. Wow. Hats off to those maintenance guys...       :-)

[John H Watson]

It really depends on what caused the leak. In some cases the broken part can simply be a short section of flexible pipe with threaded connectors on each end. Problem identified, parts found, parts replaced. A bit longer for fluid refill, checks and certification. Pump failure can be much longer as there may be metal contamination. Filters have to be changed, lines flushed, etc.