Methodology

Stage 1 defines the contract for flight-time calculation rather than claiming a final production engine. Each route stores great-circle distance, direct-flight availability, calculation source, and separate duration fields for airborne, scheduled nonstop, and connecting journeys.

Later stages can add aircraft cruise assumptions, climb and descent allowances, taxi or operational padding, airport-specific route assumptions, and directional prevailing-wind adjustments without changing the page model.

Connecting journeys are never labelled as direct-flight durations. Routes that need manual research or richer connection modelling stay out of the sitemap until they pass the publication gates.