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-   -   Entered Reserve Fuel Weight to the FMC (https://www.pprune.org/tech-log/171607-entered-reserve-fuel-weight-fmc.html)

JABBARA 19th April 2005 19:34

Entered Reserve Fuel Weight to the FMC
 
Hi.
As extracted from JAR OPS 1.255 (c)

"(c) An operator shall ensure that the pre-flight
calculation of usable fuel required for a flight
includes:
(1) Taxy fuel;
(2) Trip fuel;
(3) Reserve fuel consisting of:
(i) Contingency fuel
(ii) Alternate fuel, if a destination
alternate is required. (This does not
preclude selection of the departure
aerodrome as the destination alternate);
(iii) Final reserve fuel; One smart guy insists "

In the company, we do enter sum of last two amount of fuel [i.e (ii)+(iii)] to the B 737 Performance Initilization page. However one smart guy insists that we should enter sum of (i),(ii) and (iii) as he understands from above paragraph of JARr OPS.

Do you think this guy is smart enough?

Regards

CaptainSandL 19th April 2005 20:02

You don't include the contingency fuel in the FMC Perf Init page because the assumption is that it may have been used along the way.

Contingency is unforseen fuel burn eg not getting the optimum level, stronger than forecast headwinds or being put on radar headings etc.

Gary Lager 19th April 2005 21:08

There are regulations, born from JARs but incorporated into every airline ops manual that I am aware of, which lay down a specific set of conditions whereby you can arrive at your destination airport with less than (ii) and (iii) on board; but never less than (iii).

In other words, allowing you to burn your alternate fuel but still land with (what we also call) final reserve fuel on board.

We can burn the 'Contingency' fuel (i) at the holding point if we want, or by taking an extended routing, or by using lots of Anti-ice etc etc, as long as we can land at my destination with (ii) + (iii) on board (or just (iii), under the circumstances mentioned above).

Therefore, I believe (and my company SOPs agree) a much useful application of the USING RSV FUEL message in the B737 FMC (resulting from that input of that RSV FUEL figure you mention), is to alert us when we are no longer predicted to land with (ii) + (iii) on board; i.e. to prompt us to check whether the conditions are OK for us to continue.

Contingency fuel (i) = to allow for contingencies en-route; as Capt S&L says, it could already be gone.

JABBARA 20th April 2005 06:47

Thank you folks,

I've got tghe message.

BOAC 20th April 2005 12:31

JABBARA - there is nothing to stop you entering whatever figure (greater than CMR) you wish into the FMC, as long as all the crew know
a) why you have done it
b) what it means
c) what you are going to do when you get the warning 'using reserve fuel'

Doing it the way your 'smart guy' says has a little merit in as much as it will alert you to the using of some of the contingency fuel, but since you are extremely likely to use some of that I would question the value - and, of course, boxes a), b) and c) above are 'ticked'? I personally do not see the point, and competent crew should NOT need a computer to alert them to unplanned burns.


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