Air Transport World

Silencing strategies.

Numerous approaches are available to achieve compliance with upcoming noise limitations

U.S. airlines are on course to hush their remaining Stage 2 aircraft by the looming Dec. 31 deadline, say the manufacturers of Stage 3 conversion systems, while operators elsewhere in the world are lining up to quiet their fleets to meet compliance dates stretching into 2002. Carriers are choosing among solutions ranging from engine muffling through aerodynamic modifications to re-engining as they debate whether to retire or retain their older airplanes.

The only re-engining program currently active appears to be BFGoodrich's Super 27 conversion--developed by Valsan and acquired by Rohr, now part of BFG--which replaces the Boeing 727-200's Pratt & Whitney JT8D-7/-17s with new 20,000-lb.-thrust JT8D-217Cs, with the throttle-push 21,000-Ib.-thrust -219 used for high-power applications. Program Manager Robert Korn says 32 airplanes have been converted to date, including 11 for FedEx and four for Sun Country, and 22 more will be completed this year, 18 in 2000 and l8 in 2001. Cost of the package, which produces significant performance improvements, is $8.6 million--less around $2 million for the resale value of the removed engines and hardware, plus some 8,000 man-hours of installation labor.

Earlier, Dee Howard/Alenia re-engined 727-100s with Rolls-Royce Tay 651s for UPS. In a McDonnell Douglas-developed program starting in 1980, many DC-8-60 operators replaced JT3Ds with CFM56s to create the dash 70 series, of which UPS is the largest operator with a fleet of 49.

Sellers of Stage 3 hush kits include FedEx Aviation Services Inc., in partnership with P&W, for the 727; Nordam Group, teamed with P&W, and AvAero, on its own, for the Boeing 737; ABS Partnership, again jointly with P&W, for the DC-9; and Burbank Aeronautical Corp. and Quiet Technology Venture Ltd. for various aircraft including the DC-8, 707 and BACI-11. Offerers of aerodynamic hushing solutions include Raisbeck and DuganAir. …

Log in to your account to read this article – and millions more.