When Gulfstream announced the 7,000 nm range, .85 Mach cruise G650 in March 2008, it surely got the attention of product planners at Bombardier Business Aircraft in Montreal, according to company insiders. The G650 gives Gulfstream an aircraft with a larger cabin diameter than Bombardier's top-line Global Express XRS, along with higher cruise speeds, shorter runway requirements, better fuel efficiency, higher typical operating altitudes and a lower cabin altitude.

Bombardier, as a result, is firming up plans to launch development of a successor to the 6,274 nm range Global Express XRS in mid 2010 that would be able to compete head-on with Gulfstream G650, according to sources close to the program. Bombardier's sales force understandably is tight lipped about the program and potential customers are required to sign iron-clad non-disclosure agreements before receiving confidential briefings. Nonetheless, details are starting to emerge.

The Canadian firm's next gen, flagship business jet may retain the Global Express XRS's fuselage barrel, since current Global operators are satisfied with the aircraft's cross section. But Bombardier may stretch the cabin by as much as eight feet. The cabin will likely will be plugged both ahead of and behind the wing both to create a larger cabin than G650 and to correct a forward CG condition that is common to most Global Express aircraft. Completed aircraft typically have a 26 to 28 percent mean aerodynamic chord (MAC) CG. That creates excessive horizontal stabilizer trim drag which in turn eats into the aircraft's advertised 6,274 nm range. Bombardier's range projections for Global Express XRS are based upon a more favorable 33 percent MAC CG, according to knowledgeable sources.

Assuming that the new Bombardier flagship will be able to fly 7,000 nm, it will have to carry up to 5,000 lb more fuel and/or it will need considerably more fuel-efficient engines than the Rolls-Royce BR710 turbofans that power Global-series aircraft, plus a new wing that is larger and has better lift-to-drag characteristics than the Global's 1,022 square foot wing.

Company insiders say that up to seven or eight percent of the range increase will have to come from new engines. That much of a fuel economy improvement may rule out using an evolutionary engine in the Rolls-Royce BR700-family, such as the BR725 that powers G650. So, Bombardier may need to look outside the engine families typically used to power current-production large-cabin business aircraft. And, it's likely that a clean-sheet wing will be needed, one with better aerodynamics, more area and more fuel volume. The wing and other aerodynamic improvements should net a two to three percent range increase. It's also likely that the successor to Global will have full, fly-by-wire flight controls because that would enable designers to relax aerodynamic stability resulting in less trim drag and greater fuel efficiency.

Look for an announcement about the new Bombardier flagship, perhaps as soon as EBAA 2010 in Geneva.

Photo credit: Benet Wilson