Boeing is proposing to begin offering increased-gross-weight (IGW) versions of the new 737-700 passenger aircraft from mid-1998 as follow-on derivative developments to the planned Boeing Business Jet (BBJ).

Three new IGW variants of the 737-700 are now under study - an extended-range passenger aircraft, a convertible quick-change jet and, possibly, a dedicated freighter. The aircraft are all spin-off developments of the BBJ and, as such, will be covered by the same basic type certification amendment planned for the BBJ, says 737-700IGW/ 900/BBJ chief programme engineer Gil Key.

Like the BBJ, the variants will use a 737-700 fuselage, combined with the strengthened wing, centre body and landing gear of the larger -800. The CFM International CFM56-7-powered aircraft will have an increased maximum take-off weight (MTOW) of 77,560kg.

In the case of the 737-700ERX passenger jet, the increased MTOW will translate into longer range. It will be able to carry an extra 6,020litres (1,590 US gal) of fuel in three auxiliary belly tanks, which, depending on seat configuration, will extend the aircraft's range beyond 6,475km (3,500nm).

The quick-change 737-700C will offer airlines the option of carrying passengers or palletised freight. Boeing has already begun design work on a cargo-handling system and side door for a military combi version ordered by the US Navy. The two aircraft are scheduled for delivery in 2000.

Boeing is also looking at offering airlines a purpose-built 737-700 freighter and, possibly, a commercial combi variant. The latter version is likely to require a separate US Federal Aviation Administration type certification from that of the -700IGW/BBJ.

Type certification of the BBJ is scheduled to be completed by December 1998, with initial delivery, after cabin fitting-out, following five months later. A range of longer-term refinements is being considered, such as wing-tip extensions. "We will be looking at higher altitude, speed and aerodynamic efficiencies," says BBJ vice-president Tom Lindberg.

Boeing has announced four more BBJ purchases, increasing the total orderbook to 29 aircraft. "I fully expect we will close the year with somewhere between 30 and 35 orders," adds Lindberg.

Airbus Industrie, in the meantime, says that it has firmed up the first Asian order for the A319 Corporate Jetliner, boosting its order backlog to eight aircraft. The first business jet is scheduled for delivery in May 1999, with both CFM International and International Aero Engines (IAE) claiming to be selected the first aircraft.

IAE is offering the improved hot-and-high engine-software package for the Corporate Jetliner. The planned V2527M -A5 turbofan will be rated at 120kN (27,000lb) thrust.

The CFM56-5B7/P is also being sold at the higher thrust rating. As a result, Airbus is looking at offering the higher-weight versions to airline customers interested in a long-range A319.

Source: Flight International