Guy Norris/LOS ANGELES
Aviation Partners Boeing (APB) is to start flight tests of a winglet-equipped Boeing 747-200F in mid-May and flight tests of a similarly equipped 737-200 by July. The joint venture aims to offer blended winglets for retrofits to "Classic" 737 and 747 fleets.
The leased 747 will be flight tested initially without winglets in mid-April to ascertain baseline performance. After the loads survey tests, the aircraft will be grounded for "around two weeks" while the 4.4m (14.5ft)-high winglets are added, says Joe Clark, chief executive of Aviation Partners. "We will then put the winglets on for a couple of weeks, and see what sort of performance improvement we get out of it".
The programme will be managed from APB's site in Seattle, although flight tests will be held in Mojave or Ontario, California.
The proof-of-concept winglet equipped 747 programme will be used to establish potential performance gains as well as the amount of structural reinforcement required in the outboard wing to accommodate the carbonfibre devices. The Aviation Partners/ Boeing joint venture expects to gain improvements of 5-7% in specific fuel consumption and in hot and high performance and range. Assuming a successful test effort, APB plans to start marketing the winglets to 747 operators by year-end and to offer the first retrofits by May 2001.
The 737 flight test effort was to have begun in May, but will not start until June/July at the earliest. APB says interest is high in the potential benefits of the winglets, which could make the hot and high performance of the older 737s "very competitive" with the Airbus A320 family, says Clark, who expects a big market.
The "Classic" 737 winglet is based on the design adopted for the Next Generation/BBJ versions. Flight tests of the winglets on the BBJ began last week, having been delayed by the recent engineers strike. "We will move ahead with that aggressively," says Clark, adding that winglets are in full production for more than 40 BBJs.
Source: Flight International
