71Zulu From United States of America, joined Aug 2006, 2765 posts, RR: 0 Posted (5 months 1 week 4 hours ago) and read 15561 times:
What is going on?
Was a cause determined for the last leak?
TOKYO (AP) -- Japan Airlines has reported a fuel leak in a Boeing 787 Dreamliner for the second time in a week amid a U.S. safety review of the aircraft.
Narita International Airport outside of Tokyo says JAL reported a 100-liter fuel leak in a 787 during an inspection Sunday. The aircraft reportedly was the same one that had a fuel leak in Boston last week.
CF-CPI From Canada, joined Nov 2000, 854 posts, RR: 0 Reply 3, posted (5 months 1 week 2 hours ago) and read 14776 times:
Quoting 71Zulu (Thread starter): The aircraft reportedly was the same one that had a fuel leak in Boston last week.
Perhaps we've just found the dog in JAL's 787 fleet. Every fleet has one: NW's A320 N302NW ('Christine' the Airbus from Hell) and TW L1011 N11005 (chronic landing gear issues). I'll be convinced of true 787 problems when a pattern of similar malfunctions shows up across multiple aircraft.
PHX787 From Japan, joined Mar 2012, 5102 posts, RR: 14 Reply 7, posted (5 months 1 week 1 hour ago) and read 14394 times:
In other news, I changed my underwear this morning
Guys, read that snippet from the AVherald about all this. Fuel leaks happen all the time for a plethora of reasons. This is only sensationalist media.
tdscanuck From Canada, joined Jan 2006, 12709 posts, RR: 80 Reply 8, posted (5 months 1 week ago) and read 13856 times:
Quoting 71Zulu (Thread starter): Narita International Airport outside of Tokyo says JAL reported a 100-liter fuel leak in a 787 during an inspection Sunday. The aircraft reportedly was the same one that had a fuel leak in Boston last week.
Since it's the same airplane, it's far more likely that this is the same cause as the last leak and they just didn't fix it the first time. Having the same symptom on the same airplane with two independent causes is not unheard of, but it's really rare. They're probably working their way through the Fault Isolation Manual.
Stitch From United States of America, joined Jul 2005, 26952 posts, RR: 83 Reply 12, posted (5 months 6 days 23 hours ago) and read 13449 times:
Quoting KarelXWB (Reply 10): "An open valve on the aircraft caused fuel to leak from a nozzle on the left wing used to remove fuel, a company spokeswoman said."
"In Boston, a different valve on the plane opened, causing fuel to flow from the centre tank to the left main tank."
Is fueling and de-fueling performed with different attachment points to the fuel system?
If not, I wonder if both incidents involve the same valve and the nuance is being "lost in translation".
I'm assuming you're talking about fuel dumping? Yes, it can. Check this video out. It features testing on the Fuel Jettison System. It's pretty neat! http://www.youtube.com/watch?v=AoDQrkSGIZc
Above the planet on a wing and a prayer, my grubby halo, a vapour trail in the empty air...
wjcandee From United States of America, joined Jun 2000, 4591 posts, RR: 18 Reply 18, posted (5 months 6 days 20 hours ago) and read 10855 times:
With respect to these incidents, the fuel jettison isn't implicated. Rather, it might possibly be related to the system by which overflow is vented overboard so as to not impinge the integrity of the wing.
If you pump too much fuel into the wing tank, it goes overboard. It doesn't ask, it just goes.
This can happen because you flip the pump on to move fuel from the CWT into a wing tank that is already-full.
It can also happen on some aircraft when you are drawing fuel from the CWT to use in the engines. Because the fuel system always moves *more* fuel to the engine than it can consume (same thing with diesel engines), the excess gets returned to the fuel tank, except that it goes back to the wing tank not the center tank. Running off the center tank, you can overfill the wing tanks if you aren't careful, resulting in a stream of fuel venting overboard.
Accordingly, it seems to me that in the 40-gal Boston spill and the 25-gal recent venting, this could well be pilot error, although the airline seems to think otherwise.
It is interesting, however, that these events are happening to JAL, who put the aircraft into long-haul service very quickly, and not to ANA, which really took its time. Suggests the possibility, at least, of training hiccups.
flood From United States of America, joined Feb 2009, 1133 posts, RR: 1 Reply 20, posted (5 months 6 days 16 hours ago) and read 8149 times:
Quoting wjcandee (Reply 18): Accordingly, it seems to me that in the 40-gal Boston spill and the 25-gal recent venting, this could well be pilot error, although the airline seems to think otherwise.
The spill at BOS was attributed to a faulty valve, according to a JAL spokesman. I also find pilot error rather unlikely as they will have been working with Boeing on the issue and yet the plane has been out of service for some 5 days now.
Quoting wjcandee (Reply 18): It is interesting, however, that these events are happening to JAL, who put the aircraft into long-haul service very quickly, and not to ANA, which really took its time. Suggests the possibility, at least, of training hiccups.
Possible, sure... anything is possible. Including the Airbus ninja striking again
KC135Hydraulics From United States of America, joined Nov 2012, 165 posts, RR: 0 Reply 21, posted (5 months 6 days 16 hours ago) and read 7958 times:
Fuel leaks... no big deal! I run a hydraulic mule on KC-135s for defuels on nearly a daily basis. Reason? Fuel leaks. We've got a revovling door of 135s going through fuel cell for maintenance due to fuel leaks. Granted, 50 year old jet vs. brand new production, but when you have 30k+ gallons of fuel sloshing around it's inevitable these things will happen. Valves do go bad too. I've seen fuel venting overboard on the 135 quite a bit due to bad fuel level control valves being stuck open and overfilling a body tank, which will vent overboard when maxed out.
tdscanuck From Canada, joined Jan 2006, 12709 posts, RR: 80 Reply 22, posted (5 months 6 days 16 hours ago) and read 7936 times:
Quoting Stitch (Reply 12): Is fueling and de-fueling performed with different attachment points to the fuel system?
No. There is an independant valve that must be opened to enable defuelling but it's the same connector to the truck.
Quoting b78710 (Reply 15): Does the 787 have jettison capabilities?
Yes.
Quoting wjcandee (Reply 18): Because the fuel system always moves *more* fuel to the engine than it can consume (same thing with diesel engines), the excess gets returned to the fuel tank, except that it goes back to the wing tank not the center tank.
No. The 787 doesn't use a return-to-tank system. The fuel pumps just deadhead against the engine. Excess fuel does not come back to the tank.
KC135Hydraulics From United States of America, joined Nov 2012, 165 posts, RR: 0 Reply 23, posted (5 months 6 days 16 hours ago) and read 7903 times:
Does anyone know what they're using on the 787 for couplings? For example, do they use Marman or Wiggins fittings for joining fuel lines together? I can easily see how some new hire at the production line could incorrectly assemble something like a Marman clamp if that's what they're still using. They hold for a little while and then decide to pop catastrophically when they can't take it anymore.
BIZJETTECH From United States of America, joined Jan 2013, 2 posts, RR: 0 Reply 24, posted (5 months 6 days 16 hours ago) and read 7704 times:
That is why airlines employ maintenance personnel!!! Every aircraft has issues, even new ones. If the news covered every aircraft maintenance issue, nobody would ever fly again.
25 wjcandee: Ah. Danged newfangled technology eliminating one potential reason that fuel going overboard ain't the plane's fault!! [Edited 2013-01-13 20:42:51]
26 seahawks7757: Let us not forget that fuel leaks was something that plagued the 787 test program too, as seen here. It happens- http://www.flickr.com/photos/seahawk.
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