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Union Agreements & CBA: The Complexity of Costs

While regulatory rules (EASA FTL) dictate what is legal, Collective Bargaining Agreements (CBAs)—the contracts negotiated between airline management and labor unions—dictate what is expensive.

Airline companies have their own sets of rules and pay structures that optimization engines must evaluate. Unlike FTL rules which are universally applied across Europe, CBAs vary drastically from airline to airline, and even between pilots and cabin crew at the same airline.

1. Pay Guarantees and "Rigs"

Crews are paid a fixed amount aside from the actual hours they fly. To ensure fair compensation, CBAs feature "rigs" (guarantees) that penalize airlines for inefficient scheduling. The solver must calculate the cost of a pairing by evaluating these complicated rules.

pie title Typical Cost Comparison in an Inefficient Duty
    "Actual Flight Pay" : 40
    "Duty Minimum Guarantee Penalty" : 30
    "TAFB Rig Penalty" : 30

Common Cost Structures

  • Min Daily Guarantee (MDG): Even if a crew member only flies a single 1-hour flight, they might be guaranteed a minimum of 4 or 5 hours of pay for that duty day.
  • Duty Rig: A ratio comparing total elapsed duty time to flight time. (e.g., 1 hour of pay for every 2 hours on duty).
  • Trip Rig (TAFB): A ratio calculating pay based on the total Time Away From Base. (e.g., 1 hour of pay for every 3.5 hours away from base).

The Rave cost property will evaluate all these rules and return the MAX(FlightPay, DutyRig, TripRig) to the solver.

2. Rostering Fairness & Bidding

In the rostering phase (assigning trips to named individuals), union rules become highly personal:

  • Seniority Bidding: Senior pilots get preferential choices for weekends off, specific destinations, or avoiding night flights.
  • Fair Share / Equilibration: The optimizer must distribute the lucrative (high-paying) trips and the exhausting (multi-sector) trips evenly among the crew pool.

3. Soft Constraints vs. Hard Constraints

While a WOCL violation is a hard constraint (illegal), assigning a pilot an undesirable schedule might just be a Soft Constraint. In Rave, soft constraints are implemented by adding artificial mathematical penalties to the cost property. The optimizer will try to avoid these solutions unless no cheaper alternative exists.