Private Jet Engine
The sound of aviation success
As of December 31, new Stage 5 noise standards go into effect for new transport-category aircraft, notes Dave Higdon. For lighter aircraft, the change becomes effective three years later. Still, BizAv is ahead of the curve…again!
As often happens, the new FAA regulation, proposed early last year and finalized on October 4, came about to harmonize the US with standards adopted by the International Civil Aviation Organization (ICAO) back in July 2014.
From the Federal Register: “This change reduces the noise that may be produced by newly certificated airplanes and harmonizes the noise certification standards for airplanes certificated in the United States with the standard adopted by the International Civil Aviation Organization in Annex 16, Volume 1 Chapter 14, effective July 14, 2014.”
For operators of existing aircraft and many in development with a pending airworthiness certificate application, the rule change imposes no impact.
The rule change grandfathers aircraft flying on airworthiness certificates applied for before December 31 – just as the Stage 3 and Stage 4 standards grandfathered Stage 2 aircraft for a period.
Ultimately, Stage 1 and Stage 2 aircraft were phased out under earlier rules. The result? Something everyone should enjoy - quieter jets.
Business Aviation: Ahead of the Game
Just as Business Aviation lead the way to glass cockpits; GPS navigation; and in-flight internet connectivity, business aircraft OEMs have actually been working toward these quieter standards for years.
The fact that the new rule gives manufacturers of lighter aircraft until 2020 to comply simply means that business aircraft operators will enjoy reduced engine and airframe noise years ahead of the regulatory fiat.
But there will be no downside for operators of 1980s and 90s-era Stage 3 business jets (save the higher fuel consumption and maintenance costs of older Stage 3 powerplants).
The FAA declined to act on comments seeking a retirement date for Stage 3.
The difference in sound level will be dramatic, however. The new rule calls for Stage 5 aircraft to measure at least 7dB below the maximum level for Stage 4 aircraft (sound pressures decline by half for every 3dB reduction). So the sound level produced by engines on new Stage 5 aircraft must come in at about one-fifth that of Stage 4 jets – quiet enough, surely, to satisfy all but the most ardent opponent of aircraft noise.
It's difficult to imagine such folks being satisfied with anything less than total silence from aircraft engines, though, because as aviation has reduced its own noise footprint, the noise footprint of their complaints has remained unchanged.
Progress is progress, though, and aviation operators continue to act as good neighbors, even if the complaining neighbors won't hear it.