reasonably necessary

In the context of a carrier's departure from a collective bargaining agreement during a lawful strike, 'reasonably necessary' must be 'construed strictly': the carrier 'must respect the continuing status of the collective bargaining agreement and make only such changes as are truly necessary in light of the inexperience and lack of training of the new labor force or the lesser number of employees available for the continued operation. The collective bargaining agreement remains the norm; the burden is on the carrier to show the need for any alteration of it.