Gulfstream Aerospace took the wraps off its newest model, the G450, at the NBAA Convention last month. The fourth example (S/N 4004) of the GIV-X (or next-generation GIV) was on static display at Orlando Executive Airport, along with two G550s, a G400, a G200 and a G100.
“The G450 was developed over the last two years in parallel with the G550,” said Pres Henne, Gulfstream senior vice president of programs. “This was the first time that Gulfstream has developed two new models concurrently, and the G450 has benefited from a number of systems originally developed for the G550.” Following the creation of a G550 prototype in 2001, Gulfstream immediately began work on the G450, dubbed the GIV-X at the time.
The first G450 (S/N 4001) took to the air on April 30 this year and has now flown more than 100 hours. S/N 4002 flew on June 12, S/N 4003 on July 22 and S/N 4004 on September 18. Together the fleet has accumulated more than 200 hours. FAA certification is expected in the third quarter of next year, followed by JAA approval in the fourth quarter and entry into service in the second quarter of 2005.
Externally, the $33 million (completed) G450 does not appear much different from the $31 million G400/ GIV, but there are subtle changes. The G450’s fuselage is actually 12 inches longer than the G400’s and all of this is in the nose, which the G450 inherited from the G550. The cabin door has been moved aft three feet and new single-pivot fixed-nozzle Nordam thrust reversers replace the target-type reversers on the G400/ GIV. These lighter composite thrust reversers took 700 pounds out of the aircraft, Henne said.
Inside, the differences are more dramatic. The G550 nose section, relocated door and modified avionics cabinets on both sides of the aisle have opened access to the G450’s cabin. In the cockpit, the Gulfstream/Honeywell PlaneView integrated avionics system, developed for the G550 and also standard on the G500, dominates the instrument panel with four 13-inch by 10-inch flat-panel LCDs. PlaneView incorporates three fully synchronous flight management systems, a side-stick cursor-controller, a head-up display and the Gulfstream/Kollsman enhanced vision system.
Less visible–though perhaps equally important–changes improve the performance and reliability of the G450. The 13,850-pound-thrust Tay 611-8C turbofans, though rated at the same takeoff thrust as the G400’s Tay 611-8s, provide 6 percent more thrust at 5,000 feet (ISA +15 degrees C) and 2 percent better fuel burn, giving the airplane 250 nm more range than the G400, for 4,350 nm at Mach 0.80. Said Henne, “On a 3,000-nautical-mile mission, the G450 will burn 1,300 pounds less fuel than the G400.” The -8C also incorporates FADEC, a larger-diameter fan, modified high-pressure turbine and new bypass/core mixer. Maintenance intervals have been extended to 6,000 hours for midlife and 12,000 hours for full overhaul.
Gulfstream places the GIV’s dispatch reliability rating at 99.7 percent, but still looked at addressing and upgrading those systems that historically required the most service attention. “We took the top 10 high-removal items on the GIV and were able to improve nine of them on the G450,” he said.
The more capable and reliable electrical power system of the G550 replaces the G400’s electrics. Two 40-kVA integrated drive generators and a 40-kVA APU generator provide improvements in electrical power capacity, no-break power transfer capability and added redundancy. A new Honeywell 36-150 APU provides improved reliability for engine starting, better performance for cabin temperature control and better high-altitude electrical power capacity. It also runs more quietly than the G400’s APU.
Cabin comfort is enhanced by a dual-pack environmental control system based on the G550 air-cycle machines and a three-zone (cockpit plus two cabin zones) digital temperature control. A G550-style passive door seal and dual digital pressurization system give added redundancy and safety. Maximum cabin altitude has been reduced from 6,500 feet to 6,000 feet.
Other systems that the G450 shares with the G550 include the nose landing gear, nosewheel steering, oxygen system and fire-extinguishing system. The G450’s wing and tail are the same as those on the GIV/GIV-SP/G400.
Gulfstream expects that the commonality in flying qualities and operation of the G450 and G550/500 will convince the FAA to issue the same type rating for the G450 as the G550/500, with a minimal amount of “differences” training, primarily on the engines.