View Full Version : Re-Clear flight plans
1st Dec 2011, 10:06
Can someone do me a massive favour and please explain to me in laymans terms how re-clear flight plans work? I've looked all over the net.. and not found anything that really explains it very well... :ugh:
We have to carry 5 or 10% (Less in Europe) Contingency Reserve Fuel based on the required fuel from departure to destination, so for a long haul 747 flight that can be 10-12,000 kgs.
So if we find a destination along the route, lets say Gander for New York, we will dispatch to Gander with fuel that includes 5/10%.
We will have calculated the required fuel from that point to New York, if the weather conditions etc are suitable, the flight will reclear/re-dispatch from a point along the route to New York.
As the flight time is lets say 90 minutes, the fuel required is 12,000 kgs, 10% is 1,200 kgs which results in a fuel saving of 8,800/10,800 kgs.
You have achieved savings due to not carrying additional fuel, you might be able to carry additional payload, or you might have avoided a technical stop due to limited fuel.
Thats basically a KISS explanation.. :)
1st Dec 2011, 13:29
Full explanation can be found in FAR 121-631 Planned Redispatch/Rerelease
Hope that assists, though for US ops only, but as Mutt is in the Kingdon (I think) Saudi regs still apply these, I am to be corrected as tis many moons since I sat in JED.
Saudi Arabia uses the US FAR's in conjunction with ICAO Annex requirements :)
For example, Saudi Arabia certified First Officers before the USA introduced 61.55
1st Dec 2011, 13:56
Thks Mutt, tis a few years since I had any ctc with SV Dispatch either in JED or LHR.
I was with UACI for the SV lease contract. then Lockheed/Jeppesen Dataplan
14th Dec 2011, 11:26
Thanks mutt, so who decides on the re-clear point? is that done manually or do you allow your planning system (jetPlanner in this instance) to do it automatically?
14th Dec 2011, 14:48
As for EU-Ops, don't know which one you are asking about, then it is called RCF-procedure (Reduced Contingency Fuel) that used to be called a Re-clearance flightplan before but has been changed a bit now. Not to be confused with reducing the total contingency fuel to 3% rule in EU-Ops.
In EU-Ops you generally need to have 5% contingency fuel, basically 5% of the total trip fuel.
So if you are tight with fuel and/or payload and you are flying from A to B. Then somewhere along the route about 3/4 of it or a bit further depending on many things you choose a secondary destination called Dest 2, if we refer to B as Dest 1. Before Dest 2 you choose a decision point(DP) along your route at which you are required for a certain minimum fuel, which consists of trip fuel from DP to Dest 1, alternate fuel from Dest 1, final reserve and 5% contingency fuel of that trip fuel (from DP to Dest1). So in your RCF-flightplan there is no contingency fuel calculated from A to DP, hence decreasing the minimum fuel required and/or the maximum payload.
Same is calculated from DP to Dest 2 (trip fuel, 5% contingency, alternate fuel from Dest2 and final reserve)
Provided of course that the flight is over 6 hours, multiple runways etc, weather requirements and so on, so that you will need a alternate.
So if at the DP you do not have the minimum fuel required to continue to Dest1 you shall divert to Dest2.
The decision point and Dest2 are manually selected normally by the flight planner /dispatcher when doing the flightplan of course, but there are systems that can do this automatically also.
Hope this explains
do you allow your planning system Automated within Jeppesen........
I first encountered this in a report of the pioneer nonstop flights New York to Tokyo, by Pan Am 747SPs, where the established reserve contingencies were substantial for flights of this duration. So they dispatched to Anchorage, and then when approaching there refiled onward to Tokyo. I don't know if it was a common practice before that. Certainly back in prop Transatlantic aircraft days they didn't seem too sure on departure how things were going to work out regarding how far they might geton the fuel, dependent on weather encountered, so they were maybe filing for Gander, then refiling for Boston, then finally for New York.
by Pan Am 747SPs With fuel burns over 10,000 kgs per hour and a 10% reserve fuel requirement based on flight time from departure to destination, you can easily see how much payload you can gain by doing this procedure :)
example for you, under US 121 regs: A VHHH to EGLL B744 flt plan ran straight, no redispatch, carried a 10% reserve fuel or 23,700lbs wiht a total fuel of 356400lbs. After doing the re-dispatch, 10% the reserve was cut down to 2200lbs and total fuel reduced to 329500lbs. That's just quick, and not altitude adjustments due to a lighter plane after doing the redispatch plane.
In this example, the flight was filed to EGLL, but the dispatch was to EKCH with a planned redispatch point at CHO NDB in Poland. Approaching CHO, the crew advises they have fuel required over CHO to continue to EGLL they get the re-dispatch. If not (or unable to contact dispatch or EGLL is now below mins or closed or whatever that might stop them from going), they go to EKCH.
As you can see, it's a pretty big drop in fuel required (and thus burned to carry the fuel). Our flight planning system will do an auto redispatch if we select it, but it's usually not as efficient as an actual person doing (either due to programming issues or the way we have it set up). In this case, the Auto Re-dispatch came up with a total fuel of 345100lbs
16th Dec 2011, 19:17
Using the example above, what FPL is filed? EKCH, EGLL or one of each with a A appended to the ident?
We had a similar problem today where permits required us to remain filed to somewhere we knew we weren't going, but we wondered how to tell actual destination ATC we were coming other that just through the handler. Other bloke on shift reckoned we should file another FPL with a A on end that crew switch to with ATC, but this seems clumsy ...and probably inadvisable!
You file to the planned destination, EGLL. In Item 18, you insert a RIF/ then the routing to the redispatch airport (in this case ECKH) from the redispatch point. That lets ATC know there'spossibility of a route/dest change. ATC is expecting you to continue to EGLL unless the crew notifies them otherwise.
21st Dec 2011, 09:23
Thanks - handy to know.
5th Jan 2012, 14:02
Thanks for all the replies guys, helped me a great deal.
One extra question though about field 18 RIF/
After that, do you put the whole re-cleared route in as per the FPL (including speed/level changes)?
12th Jan 2012, 12:16
The ATC flight plan should include also the new routing to the new destination airport. specified after the RIF. :ok: