Our Methodology
How we track private jet flights and calculate emissions
Data Sources
We gather aircraft and flight data from multiple reliable sources to ensure accuracy
Airport Database
Airports mapped to ICAO codes, used to calculate great-circle distance
LLC Filings
Business registration documents linking shell companies to owners
Engine & Aircraft Specs
Per-aircraft engine specifications used to calculate LTO emissions
ADS-B Flight History
Real-time flight tracking data from unfiltered ADS-B signals
Emissions Calculation
We calculate CO₂ emissions for each flight using a combination of aircraft-specific data and flight parameters:
LTO Cycle
Takeoff and landing emissions calculated using the ICAO default LTO cycle, scaled by number of engines and mode-specific fuel flow rates
Cruise Phase
Cruise emissions calculated as hours flown multiplied by per-aircraft CO₂ rate, derived from manufacturer fuel burn data
Great-Circle Distance
Flight distance approximated as straight-line airport-to-airport routing, representing minimum plausible distance flown
Tank-to-Wake Only
Output is mission CO₂ only. No reserve fuel, APU, ground power, NOx, contrails, or lifecycle emissions are included
Our Formula
Total CO₂ =
LTO CO₂ + (Cruise Hours x CO₂ per flight hour)
- Emission Factor: 3.16 kg CO₂/kg fuel
- LTO CO₂ is based on the ICAO default LTO cycle
- Cruise CO₂ rate is derived from per-aircraft engine specifications
Limitations & Accuracy
We prioritize transparency about what we know and what we estimate:
Confirmed Data
Aircraft registration numbers
Flight paths and timestamps
Aircraft specifications
Fuel burn rates (manufacturer)
Estimated Data
Flown distance
Flight duration
Cruise fuel burn
Passenger load
Disclaimers on Methodology
The data presented on Carbon Sky Index is inferential and should be understood as directional, not definitive. Emissions figures are modelled estimates based on ADS-B flight detection and aircraft specifications — they do not represent observed fuel burn or verified operational data.
Known limitations include:
- Great-circle distance underestimates actual flown distance
- Flight duration based on ADS-B detection may include taxi time or signal gaps
- LTO fuel flow uses ICAO default cycle values, not airport-specific conditions
- Cruise burn is modelled linearly and does not account for altitude, payload, or wind
We welcome corrections and additional information from aircraft operators or data providers.