Monday’s passage of the FAA reauthorization bill in the Senate brought some surprises to future ADS-B users. The FAA planned that all aircraft must carry ADS-B transmit-only “Out” equipment by 2020, but merely recommended installation of the more advanced ADS-B transmit/receive “In” units. House members agreed, but the Senate bill proposes mandating ADS-B Out on all aircraft by 2015 and ADS-B In on all aircraft by 2018. House and Senate committee members must now reconcile the two bills’ differences on this and other issues. But industry observers believe the economic impact of the Senate recommendations on the airlines, which are not planning large-scale fleet replacements before 2020, and general aviation operators, who expect a 10-year transition and optional carriage of ADS-B In, would be too severe, and the Senate’s plan will likely be withdrawn. An NBAA spokesman told AIN, “Our industry has a long history of making necessary aircraft equipment investments for operational improvements, and in promoting equipage incentives that apply equally to all operators. Specific implementation dates are always an important consideration, so we’ll be closely watching the mandates to make sure they’re workable for our members and the broader industry.”