01The gap between filed and flown
Overflight charges are the financial foundation of most air navigation service providers. In one sample ANSP, overflights make up close to 60% of all traffic. Yet many authorities still bill en-route charges from the filed flight plan or from paper strips.
Aircraft rarely fly the route they file. Weather deviations, tactical direct-to clearances and boundary crossings all change the distance flown. When billing relies on the filed plan, every extra mile is provided free of charge.
02The cost of billing the plan
Industry estimates put en-route revenue leakage at 5% to 12% for authorities that bill from filed plans or manual handover logs. Even at the low end, the numbers are significant:
Sample ANSP data: 100,000 overflights a year at an average charge of $320.
- Weather and tactical deviations extend the distance flown beyond the filed airway, especially across tropical corridors.
- Approximate boundary handovers use estimated entry and exit points, so the distance inside the FIR is never measured.
- Manual processing pushes invoicing back by weeks, delaying IATA Clearing House settlement and increasing days sales outstanding.
03One flight, two invoices
| Billed from the flight plan | Billed from radar tracks | |
|---|---|---|
| Distance | 310 NM filed | 385 NM flown around weather |
| Calculation | Rate × 310 NM × √(MTOW/50) | Rate × 385 NM × √(MTOW/50) |
| Invoice | $310 | $385 |
| Result | $75 lost on one flight | Every mile flown is billed |
If just 15% to 20% of flights deviate this way, the difference adds up to more than $1.1 million a year.
04How ABX closes the gap
- Radar and ATM track data. ABX ingests ASTERIX radar tracks and ATM system data to find the exact FIR entry and exit points and the distance flown.
- Automatic tariff rating. Your published route charge formula is applied to every flight, with weight factors, exchange rates and exemptions.
- Instant invoicing. Flights are matched and rated automatically as the data arrives, so invoices are ready instantly instead of weeks later.
- A full audit trail. Every invoice carries its entry and exit times, track data and MTOW source, so disputes can be answered with evidence.
Bill the route that was flown, not the route that was filed. For a mid-sized FIR, that can mean recovering more than $1.7 million a year.
Illustrative model based on sample ANSP data: ~170,000 annual movements, ~100,000 overflights and an average charge of $320. Leakage ranges are industry estimates.