B757 Center Tank A.D.

[Shore Guy]

All,
We have been operating our 757’s (like everyone else, I assume), with the center tank operating restrictions of A.D. 2002-19-52.
Has anyone heard…..is there a fix in the works for this?
……Thanks in advance……
:) :) :)

[Jonty]

There was talk of an annunciation for the fuel pumps below 400kgs, then there was talk of an automatic shut-off, which apparently we have just had fitted, but I have not seen yet. The end result is flying with the extra fuel is going to carry on for the foreseeable future. Also there was talk of Boeing under taking a complete re-design of the pump to allow the AD to be rescinded. but with the 757 now out of production I would be surprised if that goes ahead.

[Bus429]

Wait for http://www.airweb.faa.gov/Regulatory_and_Guidance_Library/rgPolicy.nsf/0/dc94c3a46396950386256d5e006aed11?OpenDocument

[Crowsnest]

IMHO:

Until the automatic shutoff is approved by your regulating body or company, the best operational tactic is to buy a digital watch with an alarm and work out what time the CT will reach 500kgs. You'll still get a fuel config at TOD most times even if you run it down to 0.3 because of the change in AOA.

The alarm works even if your CTFP eta in the fix page has been deleted by "direct to-s" or if you happen to be in the forward galley shooting the s***.


Just an opinion.

[dusk2dawn]

Used to figure out the approx dist to go and enter a fix.

[scanscanscan]

So around 400kgs to be considered unusable and 2000Kg total in the wing tanks equals a QRH Low fuel state drill activation.....and your computer flight plan shows divert. fuel less than 2400 kgs.
Is it wise in view of the QRH warnings to load computer flight plan fuel pluss 2400kgs?
Has the computer missed the implications of 400kgs of unusable fuel?
Has the computer disregarded the operational implications of low fuel state flight?

[Jonty]

Boeing state the 400kgs in the centre tank is usable in a low fuel emergency.

[scanscanscan]

Thank you for your reply...I was aware.....I am interested in finding out if todays 767 pilots were unhappy (as I was on the 767) on every day sheduled commercial computer fuel diversion planning being based on useing a QRH low fuel state drill with all its warnings and the required use of centre tank pumps to get at 400 kgs when this is not considered a safe practice in everyday operations.
I question if 2400ks of extra fuel should always be loaded over the normal CFPF and wonder what the subsequent court of enquiry would opinion as regards the pilots liability in loading safe fuel loads.
Up against a hostile lawyer who qoutes the QRH to him..... I think a pilot if still alive would have a very difficult time defending being 2400kgs below legal useable fuel.
My concern is that the 767 flight planning computer is not programmed to take this into account and also there may be other aircraft out there operating on what I consider possibly similar incorrect fuel loads.
I would just like to reassured the computer and the flight planning boys/girls have got it all legal and right.

[yeoman]

It also, at least theoretically, jet pumps out when main tanks <50% full. Given that a routine day puts you on the ground at say 2T per wing, that typically leaves 200kg in the middle. Our SOPs have changed to carry Flight Plan +250 kg if C Tank fuel required to reflect this. As Jonty says, if you need it, it can be used by switching pumps on rather than relying on jet pumps.

[scanscanscan]

Yes....2 tons per wing on landing and 250kgs in the centre tank...it appears someonelse has also been thinking about this one.
Is this your DIVERSION landing fuel load?
Would you be happy doing a Go a round from minimums with say 2400kgs onboard to a close in diversion as GF were planned for?
I noticed a normal takeoff and climb with an 8 ton fuel load AUH to Bahrain bought on the low fuel pressure pump lights in accelerations and the climb.
Whilst I never had to do one a 2400 fuel load go a round and straight into a low fuel state QRH drill did not seem to me a well planned and safe operation if I was challenged in the courts.
Luckily I do not have to do these things today but I do worry for you guys out there on min CFP fuel and if the computer has it all correct.....off to walk the Lab on full tanks.

[Jonty]

2400kgs is not allot of fuel to have in tanks when landing at destination. The primary div airport from where I am based is only 30 miles away, and the CFP still loads 1700kgs for the trip. We also carry 30mins holding fuel at 1500ft, about another 1700kgs, so getting to destination with less than about 3500kgs would not be a good idea. Also a full go-around will cost about 800kgs.

If you are down to 2.4T, then the low pressure lights will come on with changes in attitude and acceleration/deceleration, this is to be expected. On the 757 if the centre tank is 2.3T or less at take off we leave the centre pumps off to avoid this problem at rotation. The fuel has to be counted as payload for the ZFM calculation but other than that Boeing say its fine.

At the end of the day if your not happy with the CFP fuel then load a bit more, its your arse up there, not the computers! But I would not be happy with a CFP that put us at destination in a low fuel emergency state.

[scanscanscan]

Yes..that is what I used to do load it.
It was sometimes questioned and it did feel a bit stressfull to go against the grain of the company fuel policy.
On a couple of occasions the GF fuel planning computer failed from a heavy actual ZFW to the aircraft basic ZFW before they fixed it to fail safe.
A NY to Bahrain Airbuss fell into the trap on a quick departue and diverted into Rome for fuel.
Showed the importance of a basic pilot gross fuel load check.
As you say the computer is not up there.