Discretionary fuel from each flight's own history: the agents explain it, the captain asks what-if, both co-sign
Each flight loads the extra fuel its history needs: an estimated $2.1M a year at one hub.
See one case, screen by screen ↓Discretionary fuel, called extra fuel in many fuel policies, is the fuel a dispatcher and captain load above the legal minimum — trip, alternate and reserve. Discretionary Fuel Optimization recommends that figure for each flight from its own history: seven agents read the last 180 comparable arrivals, tonight's FAA programs and weather, and the cost of carrying the rest, and write one cited sentence. The dispatcher and the captain accept, raise or ask, and co-sign; the minimum stays locked.
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Before every flight an aircraft dispatcher and the captain decide how much discretionary fuel to carry above the legal minimum. That dispatcher extra fuel and pilot extra fuel is a judgment made in minutes, from the weather, the NOTAMs, the FAA command center advisories and the last bad night at the destination. Nobody at the desk can see what the last hundred arrivals of the same flight actually used, so the figure is set by habit: on the sample Denver to Newark evening flight, crews usually load 3,000 lb of extra fuel.
Most of it lands unused, and carrying fuel burns fuel — about 3.5% of the extra weight every flight hour. When the captain does add fuel, the reason is rarely recorded, so the fuel loading policy never learns which raises were needed and which were not. The fuel-efficiency team finds out weeks later, in a separate tool, and the next release is set by the same habit.
Estimated split for one flight's extra-fuel decision at a busy desk, by hand and with the solution. Minutes, not days.
Seven agents turn each flight's own history and tonight's FAA programs into one cited figure; the dispatcher and the captain decide and co-sign.
Thursday 15 October at Corvane Airways' Denver operations control. Marcus Reyes works the East desk, 38 departures between 16:00 and 20:00 MDT. CV 731 to Newark is due for release at 16:20, and its captain has a question. Here is what happens, screen by screen, in the working solution.
Marcus has 38 flights in his window, 6 that need him and 19 already released — 14 at the agents' figure and 5 raised with a reason, together carrying 23,700 lb less than crews usually load. CV 226 needs his co-signature on a captain's raise, CV 1189 was swapped to a 737-9 and must be re-run, CV 344 has too little history and is his call. On CV 731 the captain has asked about a ground delay.
What the agents found: “Advisory 062 proposes a ground delay program at EWR tonight; the agents re-checked CV 731 and CV 1189 at 15:56.”
The watcher reads the FAA command center feed and the terminal forecasts. Advisory 062 proposes a ground delay program at EWR from 20:00 to 23:59 EDT at a program rate of 32 arrivals an hour, with wind 310° 22 gusting 34 kt and ceilings of 1,200 ft after 00Z. EWR is marked high holding risk; SFO already has a ground delay program in effect and New York arrival rates are reduced from 19:00 EDT. It re-runs the calls each program touches and hands the changes to Marcus.
The watcher reports programs as issued; it never presents a forecast as fact.
The fuel call opens with one sentence over a strip of 180 dots — the fuel used beyond plan on the last 180 evening arrivals of CV 731 and CV 1189. A line marks the agent's 1,400 lb; a faint one marks the 3,000 lb crews usually load. Four reasons follow, each cited: the history, Thursday evenings with 12 minutes of holding on average, tonight's proposed program, and the cost of carrying the rest — 3,000 lb instead of 1,400 burns about 191 lb more, $119 and 274 kg of CO2.
Policy guard: “Minimum fuel for release is 21,800 lb — trip, PHL alternate and the 45-minute reserve — and is unchanged. The figure above is discretionary fuel only.”
Behind the figure sit the 180 comparable arrivals the history agent built at 15:38: same route, departures 16:30 to 18:30, A321neo, 4 June to 14 October. Thursdays used +826 lb beyond plan on average, ground-delay nights with pop-up holding +1,590 lb, and arrivals with 16 minutes of holding or more +1,411 lb. Each row shows the date, tail, holding, fuel loaded and fuel used, and opens its datalink record.
The history agent needs 60 comparable arrivals, else it says so; it never fills gaps.
Captain Brandt sees the same sentence, the same strip and the same conversation on her electronic flight bag, with three choices: accept 1,400, raise, or ask. She asks the question she cares about.
“Looks reasonable. But what if EWR goes to a ground delay tonight?”
Marcus sends her the ground-delay case. On the 11 arrivals with an EWR ground delay program, most of the delay was taken on the ground in Denver and 8 used under 520 lb beyond plan; 3 met pop-up holding and used 1,460, 1,590 and 1,720 lb. Each landed with the PHL alternate fuel and the 45-minute reserve intact. The strip highlights those nights, and 1,800 lb covers all 180, for about 48 lb ($30) more to carry than 1,400.
Capt. Brandt: “Thanks — that's the night I worry about. Make it 1,800.” Reason: expected holding or arrival program. A captain may always add fuel.
The co-sign screen shows the whole release: minimum fuel 21,800 lb, locked; taxi 400 lb; extra fuel 1,800 lb against the agents' 1,400; the reason; ramp fuel 24,000 lb; 180 of 180 comparable arrivals covered. Marcus confirms that the weather, NOTAMs and advisory 062 were reviewed with the captain, and that she co-signs on the flight bag.
“Weather, NOTAMs and advisory 062 reviewed with the captain.” Under 14 CFR 121.601 the dispatcher gives the captain all available information.
Release 731/15 is co-signed by Captain Brandt at 16:11 and Marcus at 16:12: 1,800 lb extra, 144 lb of fuel not burned against the usual 3,000. The Override reviewer records her raise as the 47th on EWR evening arrivals with the reason “arrival program”, and updates proposal P1 for the fuel policy engineer.
“Proposal P-1 — add 400 lb when an EWR ground delay program is proposed — is updated for Owen Takahashi.”
Owen sees every raise and cut with its reason and whether the fuel was needed: 2,067 raises in September, 431 cuts, 31% of raised fuel used. P1 rests on 47 raises, 20 of which used the extra, for +$270 a month to carry. P2 would lower SFO mornings by 200 lb: 61 raises for “personal judgment”, the extra used on 2. He can backtest, edit, reject or approve; the Director of Dispatch gives the second signature. Captain names stay hidden.
The Override reviewer proposes only; two people approve before a rule changes anything.
The Savings reporter measures September against the June baseline: average extra fuel per departure down from 2,180 to 1,830 lb across 8,880 departures, an estimated $175,200 saved, 282,800 lb of fuel not burned and 405 t of CO2 avoided. Every input of the arithmetic is on the screen. The safety counters come first: 0 landings below planned reserve, no diversions for fuel, 1.9% of arrivals using more than the agents' figure against a design of 2.5%.
“Measured against the June 2026 baseline, before the agents went live on 15 July. Estimates are labeled; safety counters come first.” At this rate, an estimated $2.1 million a year at Denver.
The same fuel call, seen by the five people who carry it — what their day looked like, and what it looks like now.
Seven agents turn each flight's own history and tonight's FAA programs into one cited figure; the dispatcher and the captain decide and co-sign.
Builds each flight's comparable arrivals — same route, departure hour ±90 minutes and aircraft type, the last 180 in 150 days at most — and the fuel each one used beyond plan, from the flight plan and the datalink fuel on block, with holding minutes and any arrival program.
Reads FAA command center advisories — ground delay programs, airspace flow programs, miles-in-trail — terminal forecasts and pilot reports, matches them to the flights in the window and re-runs the calls they touch.
Chooses the smallest 100-lb step that covers 97.5% of comparable arrivals, conditioned on tonight's programs, writes the reason in one sentence and answers what-ifs in the conversation with the dispatcher and the captain.
Re-checks every figure against 14 CFR 121.639, 121.645 and 121.647, the operations specifications and the Flight Operations Manual §7.4, and hands a flight to the dispatcher when the history is too thin.
Prices what carrying extra fuel burns, in pounds, dollars and CO2, from the aircraft type's performance factor and the into-plane fuel price.
Groups raises and cuts by reason, checks whether the extra fuel was used, backtests a rule on history and proposes it to the fuel policy engineer and the Director of Dispatch.
Writes the monthly savings and safety report against the June baseline, by fleet and by route, with every input of the arithmetic on the record.
Decide and co-sign; the captain may always add fuel. The agents propose; a named person decides.
Ask about any flight, arrival program or figure. Every answer cites its source and opens the screen it comes from.
Why 1,400 lb on CV 731 instead of the usual 3,000?
On the last 180 evening arrivals of CV 731 and CV 1189 the fuel used beyond plan averaged 316 lb, and 1,400 lb covers 177 of them. Thursdays are the heavy nights: 31 arrivals averaged 12 minutes of holding, and tonight the FAA has proposed a ground delay program at EWR. Carrying the usual 3,000 lb burns about 191 lb more ($119). The minimum of 21,800 lb is not touched.
What if EWR goes to a ground delay program tonight?
Then most of the delay is taken on the ground in Denver. On the 11 ground-delay arrivals in the history, 8 used under 520 lb beyond plan; 3 met pop-up holding and used 1,460, 1,590 and 1,720 lb. All kept the PHL alternate fuel and the 45-minute reserve. 1,800 lb covers every one of the 180; it costs about 48 lb more to carry than 1,400.
Which of my flights need me before 17:00?
6 calls need you; 2 have a release due before 17:00 — CV 226 to ORD at 16:05, where the captain raised the extra and needs your co-signature, and CV 731 to EWR at 16:20, where the captain asked about a ground delay. The other 13 are ready at the agents' figure.
How much did Denver save in September, and is it safe?
$175,200 in September: average extra fuel fell from 2,180 to 1,830 lb on 8,880 departures, so 282,800 lb of fuel was not burned carrying it, and 405 t of CO2 avoided. Safety first: 0 landings below planned reserve, 2 “minimum fuel” advisories (3 in the June baseline), no fuel diversions, and 1.9% of arrivals used more than the agents' figure, against a design of 2.5%. The dollars are an estimate; at this rate, about $2.1 million a year.
13 screens from the working solution, on its sample data. Pick one to see it large.
How the agents make the call is set by your fuel policy engineer, previewed on tonight's flights, and every change is a new policy version signed by two people.
| Setting | Default | Choose from |
|---|---|---|
| Coverage target | 97.5% of comparable arrivals | 95 · 96 · 97 · 97.5 · 98 · 99 · 99.5% |
| Minimum comparable arrivals | 60 — below it the dispatcher decides alone | From 30 to 120 |
| Step | 100 lb | Figures are rounded up to this step |
| History window | Last 180 arrivals, 150 days at most | Same route, departure hour ±90 min, same aircraft type |
| Largest cut a rule may make in a month | 300 lb per route | Protects crews from sudden drops on a route |
| Review before sending | More than 3,000 lb below what crews usually load | Shown to the dispatcher before the captain |
| When the agents re-run | New or revised FAA advisory · terminal forecast amended · aircraft swap · new MEL item | Each trigger on or off |
| Recommendation ready · escalate an open call | 90 minutes before departure · 35 minutes, to the OCC duty manager | Captain's answer expected 45 minutes before departure |
Every figure is labelled: a target the solution is built to, an estimate, a typical published result, or a proven one.
“demo” = seen in the working solution on its sample data · “estimated” = our arithmetic, shown on the Savings screen: 350 lb × 3.5% an hour × 2.6 h × 8,880 departures a month ÷ 6.7 lb a gallon × $4.15, × 12; CO2 × 3.16 (ICAO) · “typical” = published figures: Ryerson, Hansen et al. 2015 (4.48% of fuel burned carrying unused fuel); a published industry rule of thumb (about 3.5% of the extra weight burned per flight hour to carry it; published ranges run 2.5–5%); Kang & Hansen 2018, Transportation Research Part C ($61.5 million a year at one study airline, from a machine-learning discretionary fuel method); Kang & Hansen 2021, Transportation Science, on statistical contingency fuel · Regulations named: 14 CFR 121.533, 121.601, 121.639, 121.645, 121.647, 121.695; EASA CAT.OP.MPA.181 · The problem split is estimated. Corvane Airways and the people named on this page are fictional — characters and sample data in the working solution.
Discretionary fuel, called extra fuel in many fuel policies, is the fuel a dispatcher and captain load above the legal minimum — trip, alternate and reserve. Discretionary Fuel Optimization recommends that figure for each flight from its own history: seven agents read the last 180 comparable arrivals, tonight's FAA programs and weather, and the cost of carrying the rest, and write one cited sentence. The dispatcher and the captain accept, raise or ask, and co-sign; the minimum stays locked.
The dispatcher and the captain, who share operational control under 14 CFR 121.533. The agents recommend; the two of them decide in one conversation and co-sign the release. The captain may always add fuel without approval, and a dispatcher cannot cut a captain's request.
Carrying fuel burns about 3.5% of the extra weight every flight hour. On the sample Denver to Newark flight, loading the usual 3,000 lb instead of the recommended 1,400 burns about 191 lb more, $119 and 274 kg of CO2 on one flight. Published research puts the fuel spent carrying unused fuel at 4.48% of an average flight's burn.
No. Trip, alternate and reserve fuel under 14 CFR 121.639 and 121.645, and MEL fuel, come from flight planning and are locked. The agents recommend discretionary fuel only, and the Policy guard re-checks every figure against the regulations, the operations specifications and the fuel policy — it blocks, never edits, and cannot be paused.
A statistical contingency fuel figure is usually one percentile per city pair, rarely conditioned on the hour, the day or today's traffic programs. Here the figure comes from the same flight's arrivals at the same hour on the same aircraft type, adjusted for tonight's FAA programs, with the reasons written out and a what-if answered on the same history.
The Flow and weather watcher reads FAA command center advisories, terminal forecasts and pilot reports. A new or revised advisory, an amended forecast, an aircraft swap or a new MEL item re-runs the calls it touches and tells the dispatcher and the captain what changed before the release. The history behind each figure already counts the holding fuel used on past ground delay program nights, and the captain can ask what-if on those nights alone.
Yes. The agents never release a flight or cut a captain's fuel. Every raise or cut keeps its reason; the Override reviewer turns repeated reasons into a proposed rule with evidence and a backtest, and it changes nothing until the fuel policy engineer and the Director of Dispatch both sign.
The Agentic Solution Engine builds and deploys it from your requirements and documents — your fuel policy, operations specifications and a sample of past flight plans and fuel-on-block history — and it goes live once every quality gate has passed. A station starts with a backtest on its own 150 days of history, and the Director of Dispatch approves its go-live.
Recovery plans in minutes, each one rehearsed and costed, signed before anything moves.
1-min demoFlight Dispatch ReleaseEvery release checked before signature, with a source behind every number.
1-min demoNOTAM Briefing238 notices become the 6 that change the flight, each with its reason and original text.
1-min demoWe'll run Discretionary Fuel Optimization on a sample of your own flight plans and fuel-on-block history.