The new Gulfstream G500 and G600 business jets, unveiled last week at the company’s headquarters in Savannah, Ga., not only ushered in a new era for the OEM, but also provided another validation of the expertise in fly-by-wire (FBW) control systems for Thales. The French avionics company is supplying the FBW systems for both aircraft, building on its work in providing the system for the G650. Thales also provides the FBW system for Gulfstream’s flagship ultra long-range G650ER.
Thales and Gulfstream began working together in 2004, when the OEM was considering a move to fly-by-wire. The two companies spent quite some time de-risking the technology with numerous tests, including flight trials with a G550 testbed with FBW in just one channel. Following this cautious approach, a full Thales FBW three-axis system was selected for the G650 in early 2007. Experience with the G650 validated Gulfstream’s belief in FBW and Thales’s ability to deliver, and the result has become the a long-term partnership.
For the G650ER Thales needed to make only minor adjustments to the software to accommodate the aircraft’s additional fuel capacity. Recently certified, the G650ER is available as a new-build machine or by retrofit of existing G650s. The FBW system is upgraded to meet ER requirements through a software update.
Gulfstream’s G500 and G600 have required a different approach, as they are entirely new aircraft with new engines, and thus require new control laws. Additionally, the FBW system is integrated with an active sidestick controller, and the system for the G500 and G600 also includes autopilot-in-the-loop technology. Thales has also made some minor improvements in the system, such as optimization of the computing order.
In terms of hardware, the FBW system comprises two flight control computers and a back-up flight control unit, which use the latest iteration of quad-dual computer architecture and modular packaging. The system controls both primary and secondary flight control surfaces to provide better handling and safety than mechanical systems and increased comfort levels for the passengers. The system also optimizes weight and volume use.
Before the system is applied to an aircraft, it is subjected to several months of testing, beginning with individual processor cards and then moving to products. The products are then tested on the bench at system level, including actuators. This work is performed both at the Thales Canada facility in Montreal and at the main software development facility in Paris.
Once the system has been tested, the hardware is supplied to Gulfstream for testing in the “iron bird” avionics test rig. The two companies work hand-in-hand to optimize the system prior to it being installed in the flight-test aircraft. For the G500 this has already happened. Thales also provides a toolkit to Gulfstream for testing and verification that allows the OEM to make minor tweaks during flight test, which are then incorporated into the master software load.
Thales has gained a major foothold in the FBW market, having been a pioneer of the technology in commercial airliners since the company’s systems were adopted for Airbus aircraft. The company expects more to come, as FBW becomes more widespread in the business aviation sector.
“We see the market moving to fly-by-wire from the midsize [jets] and up,” Michel Grenier, vice president of Thales Canada, told AIN. “There are a lot of new programs and they will use fly-by-wire, but maybe not in all axes.” o
