Phased compliance for operators with base level

This regulation established the historical phase-out schedule for noisy Stage 2 airplanes, requiring operators to progressively reduce them from their fleet or increase quieter Stage 3 aircraft. It doesn't apply to new entrants or foreign operators not engaged in foreign air commerce.

Operators had two compliance options at each deadline (1994, 1996, and 1998):

• Option 1: Reduce Stage 2 airplanes to 75%, then 50%, then 25% of their baseline fleet
• Option 2: Increase their fleet composition to at least 55%, then 65%, then 75% Stage 3 airplanes

The "base level" is the operator's reference point calculated under §91.861. When calculations produce fractions, operators could round up to keep operating one additional Stage 2 airplane.

While these deadlines have long passed, this regulation remains part of the framework that led to today's all-Stage 3 fleet requirement in the contiguous United States.

*This is a plain-English summary for study only. The official 14 CFR text on this page is controlling — always read the current regulation and consult a CFI.*