Five years ago in an office with limited access to just a handful of Gulfstream employees, project pilots Scott Evans and Scott Martin began outlining the design of an advanced flight deck for their company’s new G500 and G600. The resulting design–the Symmetry flight deck–not only expands the envelope of avionics interface and infrastructure design but also shows how manufacturers are taking advantage of new engineering options to make flying safer and more efficient.
In this new Gulfstream flight deck it is clear that there is no effort to edge pilots out of the cockpit and replace them with technology. “We do not want to replace the pilot,” said Evans. “We have a philosophy of supporting the pilot.” What the new design does is simplify the pilot interfaces, including replacing many knobs and switches with touchscreen controls and eliminating the massive control yoke in favor of a new type of sidestick control that makes the cockpit look much less cluttered, improves the view of the instrument panel displays and helps keep pilots in the control loop.
The new sticks are the electronically linked active control sidesticks (ACSs) from BAE Systems. The sticks not only move in concert but also enable each pilot to see stick displacement and feel what the other pilot is doing with the controls and to feel force feedback programmed to match the flight condition. The yokes in Gulfstream’s fly-by-wire G650 are mechanically interconnected and act just like yokes in older non-fly-by-wire designs, and this is a design philosophy that Boeing has built into its fly-by-wire airplanes, too, so pilots can see and feel the controls. BAE has been developing its ACSs for many years and they are installed on some military aircraft, but the G500/G600 application is a first for commercial aircraft. Elimination of the yokes also means no need for a slot in the center of the pilots’ seats, so seats will be much more comfortable.
Behind the scenes of the Symmetry flight deck is a new data concentration network (DCN), which consists of 14 routers connected via Ethernet, also a first for business aviation, according to Evans. “Think of the DCN as an Internet on the aircraft,” he said. “[This setup] allows systems to be tied into the routers, which then publish systems data on the network, and that data can be used anywhere, for synoptics [displays], systems controls and health and trend monitoring. We’re monitoring more than 15,000 parameters on the aircraft.” The advantage is that critical systems data can be published to multiple routers, providing a redundant source of that data in case of a failure somewhere in the DCN.
Touchscreen Controls for the Pilots
Much of the work that Evans and Martin did involved research into pilot interfaces, which resulted in the current touchscreen controls. “We were charged with how to design the flight deck and its interface to be more capable and add more functionality and at the same time be more intuitive to the crew,” Evans explained. The result is 11 touchscreens in the cockpit (10 primary and one for the security system interface). None of the four display units in the panel is a touchscreen; these are the same 13- by 10-inch Honeywell displays that Gulfstream uses in its current fleet. Five touchscreens are by Honeywell, including two in the center pedestal and one on each side of the cockpit. The fifth is mounted behind the jumpseat and is for maintenance access and for the jumpseat occupant’s communications needs. What the four touchscreens do is replace the functionality that used to reside in the multifunction control and display unit (MCDU) and audio controls and many buttons and knobs that no longer exist on the pedestal. The only physical control on the pedestal is a flight control reset switch. The cursor control devices and palm rests were moved to the pedestal area to make room for the sidesticks. “It makes for a very clean interface,” Evans said.
The two L-3 Aviation standby units in the glareshield are touchscreens designed to replicate symbology on the PFDs. The remaining three touchscreens are mounted in the overhead panel, and these are made by Esterline Korry and take over the functions of approximately 70 percent of the knobs and switches that used to reside there.
All the touchscreens use resistive technology, which means the user must press on the screen to elicit a reaction, as opposed to the capacitive-type screen found on popular consumer tablets or the infrared grid type that Garmin employs for its touchscreen controllers. Evans and Martin spent a lot of time bouncing around in the back of vans driving over bumpy roads then flying in the worst turbulence. “We were making sure the error rate was not greater than what we now have on flight decks,” Evans said. One of the lessons learned from the bumps was the need for a plinth or handgrip around the touchscreens for finger stabilization.
The advantage of touchscreens is tremendous flexibility in, for example, designing rules for the selection of a button or placing electronic guards over a switch control. “It’s a flexibility for design that physical controls constrain you from [being able] to do,” he said.