Raisbeck has completed a feasibility study into a Stage 3 recertification of McDonnell Douglas DC-9s and is canvassing operators before committing to launch the programme.

The aerodynamic modification kit, if given the go-ahead, would be available "on or before 1 January, 2000", says James Raisbeck, president of the Seattle-based company. The company says that the kit would be installed in less than 300h at a cost of no more than $1 million. Raisbeck adds that the modification to the high-lift devices would involve "-no structural changes to the aeroplane to compromise Douglas/Boeing certification and ongoing support, no direct engine changes which would compromise Pratt & Whitney ongoing support and certification and no adverse performance changes in take-off, climb, cruise, or specific fuel consumption".

The kit is being designed for DC-9 Series 10 through to 50 aircraft, of which around 800 are still in service. Of this total, about 230 have been fitted with Stage 3 engine hushkits, leaving a maximum potential market of as much as 570. Raisbeck says that "-many DC-9s still remain to be modified to Stage 3, due in some part to the operators' reluctance to install the only currently available hushkit to meet Stage 3".

Of the surviving fleet, the largest single potential area is the Series 30, of which around 350 aircraft remain to be "hushed" to meet Stage 3 criteria.

The company has already certificated a similar package on the Boeing 727, which has been purchased by several operators, including American Airlines.

Source: Flight International