The long-delayed Falcon 5X large-cabin twinjet is on track for certification in 2020 after making its first flight from Dassault’s Bordeaux-Mérignac final assembly facility on July 5. The first test aircraft flew with “preliminary” Safran Silvercrest engines in a limited test campaign that lasted only a few weeks. A full test campaign will begin next year with “certifiable engines meeting Dassault’s specifications,” the company said.
The preliminary flight tests permitted Dassault to collect a certain amount of airframe and systems data that could not be generated during ground tests undertaken earlier this spring, testing that included low- and high-speed taxi tests. “We’re committed to limiting the consequences of the four-year engine development delay as much as possible and the short preliminary flight-test campaign is part of this effort,” said Dassault Aviation chairman and CEO Eric Trappier. “We will closely monitor the validation tests on the modified Silvercrest, which are scheduled by Safran in the coming months, as their results will be critical for meeting the 5X entry into service in 2020.”
The Silvercrest engines are slated for certification next year. Last year Safran took a one-time $720 million charge related to delays in developing the engine. Engine testing was delayed due to disclosed problems mating the engine to the flying testbed and slight deformation of the engine casing during high-temperature testing. The engines have two different takeoff thrust ratings—one for normal operations and another for hot-and-high conditions. Use of the ‘‘Rated Takeoff Thrust at High Ambient Temperature’’ (Rated TOTHAT) is limited to two periods of no longer than 10 minutes each under one-engine-out conditions or five minutes each under all-engines-operating conditions in any one flight, for a maximum accumulated usage of 20 minutes in any one flight. Each flight where the Rated TOTHAT is used must be followed by inspections and maintenance actions.
Performance Numbers
Dassault revealed the $45 million jet in late 2013. The jet’s fuselage diameter is 8.86 feet—a bit larger than that of the 8X trijet flagship. The new tube yields six and a half feet of headroom and volume of 1,766 cu ft, making the 5X even larger than the 8X. Available configurations include seating for 12 passengers. Dassault claims that the aircraft will be 50 percent more fuel efficient and cost 30 percent less to operate than competing models from other manufacturers. It will feature fly-by-wire controls with sidesticks and new Silvercrest engines (11,450 pounds of thrust each). The Falcon EASy avionics suite, based on Honeywell's Primus Epic platform, includes dual head-up displays with synthetic and enhanced vision information. The large cockpit incorporates a windshield 32 percent larger than the one on the 8X as well as pilot seats that recline 130 degrees, allowing one crewmember to rest while the other flies.
The Mach 0.9 5X has a maximum takeoff weight of 69,600 pounds and a range of 5,200 nm, which equates to 11 hours, 30 minutes in the air. It can take off from 5,000-foot runways and touch down with an approach speed of 105 knots. The aircraft's new wing design features winglets, leading-edge slats and flaperons. The cabin altitude is 3,900 feet at 41,000 feet; and 6,000 feet at the 5X’s service ceiling of 51,000 feet. The cabin, which features the Falcon HD inflight-entertainment system will be available with various layouts and with seats than can be fully reclined to produce sleeping areas for up to six passengers. The pressurized 155-cu-ft main baggage area is accessible through the aft lavatory, providing dressing space in flight. The single executive seats have been redesigned with a new shell back and mechanical functions such as slide, swivel and recline controlled by an electric switch in place of the traditional cabling system. Full-electric-function single seats are optional.
The cabin windows are 30 percent larger than those on the 8X.The entryway can be filled with natural light, courtesy of an electronically dimmable “Zenith window” skylight from Vision Systems above the galley aisle. The “smart glass” in the skylight can adjust tint in virtually any degree to modulate the amount of incoming light and solar heating.
