Stage 4 Noise Standards Take Effect

 - January 11, 2007, 6:18 AM

All jet and transport-category airplanes (those with an mtow of 12,500 pounds or more) for which application of a new type design is submitted on or after January 1 this year have to meet new noise certification levels. Stage 4 is a cumulative 10 EPNdB (effective perceived noise level in decibels) less than Stage 3 limits. Virtually all in-production business jets will qualify to be recertified under Stage 4. Although the new rule doesn’t contain a Stage 4 retrofit requirement and the FAA said it has no plans to impose such a requirement, one of the International Civil Aviation Organization’s recommendations calls for a phaseout by 2020 of Stage 3 airplanes with an mtow of more than 75,000 pounds. Separately, effective February 3, new amendments to Part 36 require a 3-dBA (decibels to the A-weighted average) noise limit reduction for new type-certified small single-engine propeller aircraft–including turboprops–weighing more than 3,307 pounds.