The 06:12 problem at KORD
When a tail goes on maintenance hold, the cascade is never one flight. Three downstream legs, twelve crew members, and a shrinking decision window are normal. OCC needs a plan that reassigns tails, re-bids crew across open legs, and stays inside FAR 117—not a single swap picked by gut feel.
The Qtangl airline demo models that cascade: N812JB unavailable at KORD, three legs at risk, and a recovery window measured in tens of minutes, not hours.
Classical first: routing + assignment
The pipeline starts with aircraft routing repair—reassigning affected legs to available tails—then a CP-SAT crew assignment over every open leg simultaneously. That is the right source of truth: deterministic, fast, and auditable.
Reserve call-up stays in the model as a high-cost feasible fallback so the solver never returns empty-handed.
Hybrid for diverse full plans
The hybrid pass operates on a bounded crew×leg micro-window. It does not claim to beat CP-SAT on speed. It surfaces up to three distinct full recovery plans with QUBO snapshots and QPU trace replay for compliance review.
When classical and hybrid tie on cost, the value is alternate crew mixes and FAR 117 evidence—not hype.
Continue the walkthrough
Open the airline OCC demo, review the methodology page, or request pilot access.