Dassault Unveils Largest Falcon Jet: 5X

By Fred George fred.george@aviationweek.com
Source: AWIN First

The Falcon 5X’s airframe and systems introduce no unproven technologies, so early serial number buyers aren’t likely to suffer major growing pains. The primary airframe is a semi-monocoque aluminum structure, with composites for the empennage, fairings, nacelles and other secondary structures.

The clean-sheet 779-sq.-ft. wing is Dassault’s first airfoil to have winglets as part of the initial design. It features a straight leading edge, a relatively modest 33 deg. of leading edge sweep, and 5-10% better lift/drag ratio than the 7X’s. The Falcon’s signature cruciform tail is retained, but the horizontal stabilizer has no anhedral.

The nose has completely new loft contours, including cockpit windows that are 32% larger than those of the Falcon 7X, making it much easier to see over the nose during takeoff, approach and landing. The flight deck is considerably more comfortable, with increased headroom and space aft of the pilots’ seats to recline either one to 130 deg. for short rest breaks. There’s also a new jump seat for a third crewmember that stows behind the right pilot’s seat.

Systems are thoroughly updated. The 5X will be the first Falcon to have a primarily AC electrical system, with 115 VAC variable-frequency starter-generators, eliminating the need for air turbine or DC motor starters. There will be only two main 3,000-psi hydraulic systems, each with a subsystem and electric power pack to provide redundancy for the flight control actuators. The fuel system is vintage Falcon, having pressurized tanks and dual-redundant fuel boost pumps.

The Dassault-designed digital flight control system is based upon Falcon 7X architecture, but it will integrate more functions, including business aviation’s first flaperons, combining flap, roll spoiler and airbrake functions in a single control surface. The cockpit will have left and right sidestick controls linked to three primary and three secondary flight control computers. While most flight control surfaces will be hydraulically powered, the trailing edge flaps will be electrically powered, a departure from the 7X.

Falcons are known for their class-leading fuel efficiency and the 5X will be no exception. No other large-cabin aircraft, except for Dassault’s own Falcon 2000S and 2000LXS, should squeeze more miles out of a pound of jet fuel on equal length trips. One reason is the 5X’s Mach 0.80 design cruise speed, relatively placid by current standards. While some large-cabin business aircraft makers now tout cruise speeds of Mach 0.85 to 0.90, shaving as much as an hour off of longer trips, Dassault’s market research indicates that longtime Falcon operators value cabin comfort, range and price above the need for speed.

With 5,200-nm range at Mach 0.80, the Falcon 5X will be able to fly eight passengers London-Tokyo, Beijing-Minneapolis or New York-Tel Aviv in 11 hr., 30 min. At Mach 0.85 it will fly London-Houston, Detroit-Moscow or São Paulo-Lisbon in under 10 hr.

Dassault is striving to make the 5X the most reliable and most maintainable business jet that it has ever built. Scheduled maintenance will come at 800-hr. or 12-month intervals. Custom-tailored maintenance programs will be offered.

The 5X provides a clean-sheet foundation for larger and longer range Falcon Jets, ones that will compete directly against the newest and most capable designs being developed by Bombardier and Gulfstream. As such, it isn’t just Dassault’s latest jet. It is a milestone in the company’s history, the end of its trijet era and the beginning of a whole new line of twin-engine, large-cabin aircraft that will be more comfortable, more capable and more cost-effective.

Construction of the first flight test aircraft is well under way. First flight is slated for the first half 2015. Look for a full report in the November 2013 issue of Business & Commercial Aviation.