Decision Point Procedure
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Decision Point Procedure
Can anyone give a good explanation of the difference between a 'Decision Point' procedure (in relation to fuel flight planning) as opposed to a 'Reclearance Procedure'.....if there is a difference?
I think "Decision Point" probably refers to Point of No Alternate in the case of flights to (mainly) island airports where it would be impractical or not possible to carry diversion fuel, e.g. Europe to Bermuda etc. On these flights an island reserve is carried (say 2 hours + holding) and there will be a point along track beyond which it will not be possible to divert to another airport.
A "Reclearance Procedure" applies to a flight which cannot load enough fuel to fly to the desired destination with all the normal reserves. In this case, assuming all the rules are obeyed, the flight may be despatched to a different "destination" with normal reserves. At some point on the way to the nearer destination it may be possible to continue to the original destination and complete the flight as planned. Whether or not this is possible will depend on how the flight has progressed (fuelwise).
Hope this helps!
A "Reclearance Procedure" applies to a flight which cannot load enough fuel to fly to the desired destination with all the normal reserves. In this case, assuming all the rules are obeyed, the flight may be despatched to a different "destination" with normal reserves. At some point on the way to the nearer destination it may be possible to continue to the original destination and complete the flight as planned. Whether or not this is possible will depend on how the flight has progressed (fuelwise).
Hope this helps!
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Yes TyroPicard, I'm trying to establish whether there is a difference between the fuel uplift required to satisfy the Decision Point procedure, and that requyired for a ReClearance Procedure.
The following is the definition for Decision Point Procedure in my Ops Manual:
Is a ReClearance any different? Anyone?
The following is the definition for Decision Point Procedure in my Ops Manual:
The Amount Of Fuel Required For Continuing A Flight From The Decision Point Shall Be The Greater Of A Or B
A Taxi Fuel / Trip Fuel To Destination Via Decision Point
Contingency Fuel, Alternate Fuel, Final Reserve Fuel.
B Taxi Fuel / Trip Fuel To En-Route Alternate Via Decision Point, Contingency Fuel, Final Reserve Fuel
A Taxi Fuel / Trip Fuel To Destination Via Decision Point
Contingency Fuel, Alternate Fuel, Final Reserve Fuel.
B Taxi Fuel / Trip Fuel To En-Route Alternate Via Decision Point, Contingency Fuel, Final Reserve Fuel
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I believe the Decision Point Procedure fuel requirements is based on the applicability of a decision point for drift-down purposes (over the Alps etc.). When your net ceiling is such that a decision point is required you must then take into account an enroute alternate and adjust fuel accordingly. The reclearance procedure should be as defined by fireflybob.
The decision point is defined in JAR OPS. Basically it applies when your net ceiling is less than 1000 ft above the highest obstacle. The DP must provide you with at least 2000 ft above all obstacles during a driftdown situation. Engine fails before the DP you proceed to the enroute alternate.
For fuel planning, apply as written in the OM.
Regards,
Darren
The decision point is defined in JAR OPS. Basically it applies when your net ceiling is less than 1000 ft above the highest obstacle. The DP must provide you with at least 2000 ft above all obstacles during a driftdown situation. Engine fails before the DP you proceed to the enroute alternate.
For fuel planning, apply as written in the OM.
Regards,
Darren
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Seat0A...Because it's a legal requirement?!
SodaPop...I know about the driftdown thing...theres also the decision point (PNR) in relation to diversion after engine failure.
Thats not waht I'm referring to.
What I'm talking about is the use of a Decision Point in fuel planning when you can't carry sufficient out of your departure airport to go direct to your destination.
You can plan to a Decision Point and perhaps continue to destination from there (or divert).
But you could also plan to a different (en route) 'destination' and 'Re Clear' from there to your true destination.
I want to know if the rules are different in these two scenarios.
SodaPop...I know about the driftdown thing...theres also the decision point (PNR) in relation to diversion after engine failure.
Thats not waht I'm referring to.
What I'm talking about is the use of a Decision Point in fuel planning when you can't carry sufficient out of your departure airport to go direct to your destination.
You can plan to a Decision Point and perhaps continue to destination from there (or divert).
But you could also plan to a different (en route) 'destination' and 'Re Clear' from there to your true destination.
I want to know if the rules are different in these two scenarios.
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JAR requires trip+5%+taxi/apu+alternate+final reserve.If you cannot load all that due to mtom restriction or performance etc you may reduce the contingency (that's the 5 % ) down to an agreed minimum figure.This is decision point procedure and the CFP must be annotated as such.A "decision point"is nominated at which the crew will decide whether to divert to the agreed en route alternate or continue to destination.You would need to have on board at that point fuel to dest+5% of THAT fuel (ie a lesser amount than the "full"contingency+alt+final reserve.
If you cannot even load up to the required fuel figure using minimum contingency you must plan on departing to a closer airfield.At a realistic descent point for that airfield the crew may "re-plan"to the original destination if they reckon they can get there with alt+final reserve.That is "In flight replanning " or "re-clearance".Yes there is still a decision involved but the diference is all about the planning stage and less about the actual flying.Both involve much fretting over headwinds and begging of direct routings.
There are a few complications and lots of discussion about eating into your alternate fuel etc but thats another can of worms.
Remember that you could theoretically use all your contingency fuel on taxi out (not quite sure how but ,hey!) and legally get airborne with just trip+alt+FR.
If you cannot even load up to the required fuel figure using minimum contingency you must plan on departing to a closer airfield.At a realistic descent point for that airfield the crew may "re-plan"to the original destination if they reckon they can get there with alt+final reserve.That is "In flight replanning " or "re-clearance".Yes there is still a decision involved but the diference is all about the planning stage and less about the actual flying.Both involve much fretting over headwinds and begging of direct routings.
There are a few complications and lots of discussion about eating into your alternate fuel etc but thats another can of worms.
Remember that you could theoretically use all your contingency fuel on taxi out (not quite sure how but ,hey!) and legally get airborne with just trip+alt+FR.
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There are various forms of dispatching an a/c but the planned fuel load on the CFP (Computerised Flight Plan) must comply with the Operators Fuel policy as approved by the Operators CAA. Typically this is trip fuel, contingency, alternate and final reserve (30 mins holding at 1500ft overhead altn).
Historically, Contingency Fuel was based on 5% of trip fuel ( climb out of A, cruise, descend into and land at B) and was there to take account of less favourable wind conditions, en-route use of anticing and ATC considerations (lower level than planned). That was when flights were of 4-6 hour duration. With the introduction of long-haul a/c and flight times of 10-13hrs this 5% was one heck of a lotta fuel so authorities agreed to a reduction in the amount of contingency fuel that needed to be carried for dispatch purposes. Hence different methods were adopted and two of which are alluded to in original question.
a) Reclear Planning
b) En-Route Alternate procedure
In Reclear planning there is a specific geographical point defined by Lat/long on the CFP.
With the ERA procedure the "Decision Point" is not defined on the CFP.
The two methods are quite different so let me give an example of "Reclear"
Flight is Singapore to Heathrow. I nominate Frankfurt as my "Reclear" or "Intial Destination" although I have every intention of flying to LHR. I must specify an Alternate airport for FRA and I must also have an Alternate for LHR.
The computer effectively calculates 2 flight plans. The first one is SIN-FRA with normal fuel policy i.e. trip fuel SIN-FRA plus 5% contingency, plus Alternate fuel (say Brussels) plus 30 min holding @ 1500ft o/h BRU. Somewhere before FRA there will be a pre-planned "Reclear Point" Ideally this would be just before Top of Descent into FRA.
Now the computer calculates the second flight plan from SIN to LHR. All CFP's start calculation on ground at Alternate with empty tanks (I'm ignoring exceptions where residual or "unuseable" fuel is taken into consideration) and work backwards towards the origin. From the first flight plan the program will know what is the fuel on board at the Reclear point and assumes that none of the 5 % contingency (SIN-FRA) has been burned off, so it is this contingency that alllows you to "go the extra distance". However for the 2nd Flt Pln the program will calculate 5% of the fuel from the reclear point to the Destination of LHR plus the Alternate fuel (say Gatwick) plus 30 mins holding o/h LGW.
So at the Dispatch stage the a/c has sufficient fuel to fly to FRA with full reserves plus an alternate and holding. It also has fuel to fly to LHR plus altn plus hold but only 5 % contingency from Reclear Point to LHR. When the a/c reaches the Reclear point, if there is sufficient fuel to proceeed to LHR plus the Altn fuel for LGW plus the 30 mins hold then the crew will continue to final destination of LHR. It is desirable (but not mandatory) that at the Reclear point the 5% contingency (rclr point to LHR) is still on board.
So the Reclear Point is a specified, pre-determined position. If memory serves the optimum point for this position is 8/9ths of the distance origin to final destination. This procedure only works with sensible selection of Initial Destn and its associated Altn. The ATC plan is filed to the final intended Destn, in this case LHR.
The other form of Dispatch (En-Rte Altn Procedure) is somewhat different. Again I will use SIN-LHR as an example.
It is not necessary to carry the full 5% contingency LHR-SIN but I do need to have something up my sleeve to guard against things going pear-shaped so I nominate an En-Route Alternate (in this case I will again use FRA) but my contingency fuel will be the greater of
a) 5% of the fuel from the En-Rte Altn to the Destn. or
b) The fuel for 15Mins holding o/h Destn (LHR) in ISA conditions taking into account any a/c performance degradation.
Item b) is a means of carrying reduced reserves but having a "quantifiable" amount. Almost invariably item b) will be the specified "Contingency). There are various caveats with regard to determination of the En-Rte Altn such as the Wx must permit a landing if required and the Wx criteria are those for an Altn rather than a destn and must be sustainable for 1 hour prior to and after likely arrival time. Rules govern where it must lie in relation to track (one being a min of 150nms from Destn.)
Now for CRUNCH Time!!
In flight a check must be made at the DECISION POINT to establish that sufficient fuel remains to continue to the Destination plus Altn Fuel Plus 30 mins Holding. If insufficient then a landing should be made at the ERA ..... OR A CLOSER DESTINATION planned. (What a lovely get-out!)
The DECISION POINT is not a pre-determined Lat/Long. It is the point at which the a/c would deviate from planned track or level in order to descend into the ERA.
Consider the case where the ERA is "on-Track" Origin-Destn and consider as typical descent distance for jet of 120 nms. Some think that the Decision Point would be 120nms before the ERA, some think the DP is Abeam the ERA but in fact the captain could elect to make his Decision 120nms past the ERA.
The above are "Dispatch Issues" and not to be confused with PNR's Crit Points or the like mentioned in other responses. Obviously Depressurisation is a consideration in Flight Planning be it for ETOPS or 3/4 jet over large expanses of water but the terminology used in original query regarding Reclearance and Decision points do not relate to these scenarii.
Hope the above clarifies.
Historically, Contingency Fuel was based on 5% of trip fuel ( climb out of A, cruise, descend into and land at B) and was there to take account of less favourable wind conditions, en-route use of anticing and ATC considerations (lower level than planned). That was when flights were of 4-6 hour duration. With the introduction of long-haul a/c and flight times of 10-13hrs this 5% was one heck of a lotta fuel so authorities agreed to a reduction in the amount of contingency fuel that needed to be carried for dispatch purposes. Hence different methods were adopted and two of which are alluded to in original question.
a) Reclear Planning
b) En-Route Alternate procedure
In Reclear planning there is a specific geographical point defined by Lat/long on the CFP.
With the ERA procedure the "Decision Point" is not defined on the CFP.
The two methods are quite different so let me give an example of "Reclear"
Flight is Singapore to Heathrow. I nominate Frankfurt as my "Reclear" or "Intial Destination" although I have every intention of flying to LHR. I must specify an Alternate airport for FRA and I must also have an Alternate for LHR.
The computer effectively calculates 2 flight plans. The first one is SIN-FRA with normal fuel policy i.e. trip fuel SIN-FRA plus 5% contingency, plus Alternate fuel (say Brussels) plus 30 min holding @ 1500ft o/h BRU. Somewhere before FRA there will be a pre-planned "Reclear Point" Ideally this would be just before Top of Descent into FRA.
Now the computer calculates the second flight plan from SIN to LHR. All CFP's start calculation on ground at Alternate with empty tanks (I'm ignoring exceptions where residual or "unuseable" fuel is taken into consideration) and work backwards towards the origin. From the first flight plan the program will know what is the fuel on board at the Reclear point and assumes that none of the 5 % contingency (SIN-FRA) has been burned off, so it is this contingency that alllows you to "go the extra distance". However for the 2nd Flt Pln the program will calculate 5% of the fuel from the reclear point to the Destination of LHR plus the Alternate fuel (say Gatwick) plus 30 mins holding o/h LGW.
So at the Dispatch stage the a/c has sufficient fuel to fly to FRA with full reserves plus an alternate and holding. It also has fuel to fly to LHR plus altn plus hold but only 5 % contingency from Reclear Point to LHR. When the a/c reaches the Reclear point, if there is sufficient fuel to proceeed to LHR plus the Altn fuel for LGW plus the 30 mins hold then the crew will continue to final destination of LHR. It is desirable (but not mandatory) that at the Reclear point the 5% contingency (rclr point to LHR) is still on board.
So the Reclear Point is a specified, pre-determined position. If memory serves the optimum point for this position is 8/9ths of the distance origin to final destination. This procedure only works with sensible selection of Initial Destn and its associated Altn. The ATC plan is filed to the final intended Destn, in this case LHR.
The other form of Dispatch (En-Rte Altn Procedure) is somewhat different. Again I will use SIN-LHR as an example.
It is not necessary to carry the full 5% contingency LHR-SIN but I do need to have something up my sleeve to guard against things going pear-shaped so I nominate an En-Route Alternate (in this case I will again use FRA) but my contingency fuel will be the greater of
a) 5% of the fuel from the En-Rte Altn to the Destn. or
b) The fuel for 15Mins holding o/h Destn (LHR) in ISA conditions taking into account any a/c performance degradation.
Item b) is a means of carrying reduced reserves but having a "quantifiable" amount. Almost invariably item b) will be the specified "Contingency). There are various caveats with regard to determination of the En-Rte Altn such as the Wx must permit a landing if required and the Wx criteria are those for an Altn rather than a destn and must be sustainable for 1 hour prior to and after likely arrival time. Rules govern where it must lie in relation to track (one being a min of 150nms from Destn.)
Now for CRUNCH Time!!
In flight a check must be made at the DECISION POINT to establish that sufficient fuel remains to continue to the Destination plus Altn Fuel Plus 30 mins Holding. If insufficient then a landing should be made at the ERA ..... OR A CLOSER DESTINATION planned. (What a lovely get-out!)
The DECISION POINT is not a pre-determined Lat/Long. It is the point at which the a/c would deviate from planned track or level in order to descend into the ERA.
Consider the case where the ERA is "on-Track" Origin-Destn and consider as typical descent distance for jet of 120 nms. Some think that the Decision Point would be 120nms before the ERA, some think the DP is Abeam the ERA but in fact the captain could elect to make his Decision 120nms past the ERA.
The above are "Dispatch Issues" and not to be confused with PNR's Crit Points or the like mentioned in other responses. Obviously Depressurisation is a consideration in Flight Planning be it for ETOPS or 3/4 jet over large expanses of water but the terminology used in original query regarding Reclearance and Decision points do not relate to these scenarii.
Hope the above clarifies.
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4PON4PIN, Wonderful! Thank you, thats exactly what I was looking for.
The 'Reclearance' option has completely disappeared from our Ops Manual and I was beginning to wonder if I had imagined there ever was another option to the Decision Point procedure we still retain.
The difference is subtle, but important.
Now that I know I wasn't imagining it I wonder why the Reclearance method has been dropped. I guess it's not a useable option for me any longer if its not included in the Ops Manual!
The 'Reclearance' option has completely disappeared from our Ops Manual and I was beginning to wonder if I had imagined there ever was another option to the Decision Point procedure we still retain.
The difference is subtle, but important.
Now that I know I wasn't imagining it I wonder why the Reclearance method has been dropped. I guess it's not a useable option for me any longer if its not included in the Ops Manual!
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Maxalt you are welcome sir/ma'am!
Noting yr profile and reading between the lines, I would hazard a guess that the reason yr Ops Manual no longer describes "Reclear Procedure" is because there is no need for it. Reclear and En-Rte Alternate Procedures are normally only used for Long-haul.
With the ERA Procedure the contingency is higher of a) or b) described in my post above.
As an example let's take an A320.
15mins hold at 1500ft would be approx 525Kgs
Contingency is HIGHER of a) or b) so what is the break-even point when a=b?
5% of the fuel from En-rte Alternate to Destination would have to be 525Kgs also. Which means 100% of fuel ERA-Destn would be 10,500Kgs which for an A320 is about 5hrs flying time!! Consequently you are better off using 5% contingency.
That being said, some Operators are able to reduce their contingency to 3% of Trip fuel so long as an en-route alternate is available which is a "variation on the theme" of ERA Procedure.
Principal applies to all a/c so a B744 would have 2.4T for 15 Mins hold making 48T as fuel ERA-Destn and since we like to have ERA close to Destn the 15Mins will normally be the governing factor.
FYI flew Ryanair STN-PIK last month: on-time departures v. friendly cabin staff, ticket £1.25 each way, sarnies on board £3 -- Magic!!
Noting yr profile and reading between the lines, I would hazard a guess that the reason yr Ops Manual no longer describes "Reclear Procedure" is because there is no need for it. Reclear and En-Rte Alternate Procedures are normally only used for Long-haul.
With the ERA Procedure the contingency is higher of a) or b) described in my post above.
As an example let's take an A320.
15mins hold at 1500ft would be approx 525Kgs
Contingency is HIGHER of a) or b) so what is the break-even point when a=b?
5% of the fuel from En-rte Alternate to Destination would have to be 525Kgs also. Which means 100% of fuel ERA-Destn would be 10,500Kgs which for an A320 is about 5hrs flying time!! Consequently you are better off using 5% contingency.
That being said, some Operators are able to reduce their contingency to 3% of Trip fuel so long as an en-route alternate is available which is a "variation on the theme" of ERA Procedure.
Principal applies to all a/c so a B744 would have 2.4T for 15 Mins hold making 48T as fuel ERA-Destn and since we like to have ERA close to Destn the 15Mins will normally be the governing factor.
FYI flew Ryanair STN-PIK last month: on-time departures v. friendly cabin staff, ticket £1.25 each way, sarnies on board £3 -- Magic!!
