The larger wing, along with the wing center section tank and feeders, also holds 20% more fuel than the G200's, enabling Gulfstream to shrink the forward belly tank and eliminate the 5,515-lb.-capacity, 67-cu.-ft. fuselage tank, replacing it with a 1,130-lb.-capacity aft belly tank. Overall fuel capacity actually is 390 lb. less than the G200's, but the more-efficient wing and new engines make up for the difference.
The G280's T-tail empennage features larger area fin and stabilizers to handle the aircraft's nearly 2-ton weight increase.
The flight-control system of the new aircraft has little in common with that of G200 other than similar pitch-control mechanisms and the stall-protection system. The roll-control system, for example, uses manually actuated ailerons with servo tabs that provide high-fidelity aerodynamic feel. Computer-controlled multi-function spoilers provide most of the muscle needed for roll control. The result is natural feel, abundant roll-control authority and well-harmonized pitch and roll forces at the yoke.
G280 is fitted with a fly-wire-wire (FBW) rudder in place of the manually actuated, boost-assisted system on the G200.
In keeping with long-standing Gulfstream design practice, G280 has no leading edge high-lift devices. The trailing edge flaps are electrically controlled and hydraulically actuated.
The aircraft boasts an updated, fully split buss electrical system with increased automatic load shedding compared to G200's hybrid split/parallel buss architecture that shares common emergency and hot battery busses. Aboard G280, there are left and right 28-volt-direct-current (VDC) 400A brushless generators, plus a 28-VDC 400A auxiliary power unit (APU) starter-generator rated for inflight use up to 40,000 ft. at reduced output. Left- and right-side 24 VDC 38AH heated lead-acid batteries, plus a standby battery, are standard.
The hydraulic system has been updated to provide additional redundancy for the FBW rudder. The left and right sides have both engine-driven and electrically powered hydraulic pumps, similar to Challenger 300. The design provides the necessary power redundancy for the digital FBW rudder.
The G280 has a new brake-by-wire system with an auto-braking function, a first for this class of business aircraft. The auto-braking system has low, medium and high deceleration levels, plus a rejected takeoff off mode for maximum braking.
The ice protection system has been changed significantly. Gone are the G200's pneumatic de-ice boots on the leading edges of the wing and horizontal stabilizer. G280 uses a bleed-air for heated wing anti-ice.
Rockwell Collins Pro Line Fusion avionics provide the backbone of G280's PlaneView cockpit. The main instrument panel features three 15-in. screens with cursor control devices on the left- and right-side ledges and left and right standby multifunction controllers [SMCs] in the glareshield panel. Gulfstream invented the SMCs to provide each pilot with a full-function electronic standby instrument system that doubles as a display and test control box. The 3 X 4-in. full-color LCD screens are in direct, head-up view of each flight crewmember.