Dassault refines EASy concept in reengineered Falcon 900EX

 - January 9, 2008, 6:10 AM

Dassault’s new EASy flight deck should enter customer service this spring on a Falcon 900EX. Early last month AIN visited the airframer’s facility in Bordeaux Mérignac, France, to see how the ongoing flight tests have refined the avionics suite. Philippe Deleume, Dassault’s chief test pilot for civil aircraft, also explained how extensive engineer-pilot interaction have improved man-machine interface.

Based on Honeywell’s Primus Epic avionics suite, EASy features a new pilot environment with four large screens in a “T” layout and a cursor-control device (CCD) for each pilot. It is expected to improve safety mainly through better crew coordination and enhanced situational awareness.

By December 4, some 150 hr had been logged on more than 60 test flights by Falcon 900EX S/N 97, the aircraft with the upgraded avionics, following its first flight last February 21. Certification should be granted late in the first quarter of this year. A second aircraft, which is expected to fly this month, will be used in addition to S/N 97 for FAA- and JAA-mandated certification of training procedures. The first production EASy-equipped Falcon 900EX was ferried across the Atlantic to Dassault’s completion facility in Little Rock, Ark., on November 27.

Customer pilot training should begin in the second quarter of this year when the first EASy- equipped 900EX flight simulator goes into operation at FlightSafety International’s facility in Teterboro, N.J. That sim should be certified almost simultaneously with the actual aircraft.

Reflecting on changes made during the flight tests, Deleume noted, “This is a matter of refinement–neither the concept nor the hardware have changed.” Flight testing has prompted such changes as making cursor movement more comfortable in flight or refining the flight-director symbology. Software improvements include introducing filters in some displays to stop image wriggling. Other refinements include “changes in the synoptic views’ color codes, better readability and enhanced overhead button identification at night.”

Crew coordination and situational awareness were the two main design drivers for the EASy flight deck. “They cause a high number of accidents,” Brigitte Bonneville, a Dassault avionics spokeswoman, told AIN. When Dassault started to contemplate a new man-machine interface in 1995, other specifications included “easy pilot input into the system, reduced pilot workload and keeping the pilot in the loop.”

This resulted in a simulator dubbed “Primevère” that Dassault built in Istres, France. “We took a lot of ideas from our military aircraft, such as the hotas [hands-on throttle and stick] concept, and scrolling pages on a screen,” Deleume explained.

In terms of hardware, “Honeywell’s Primus Epic avionics suite was the closest to our concept design, so we took it and integrated Primevère concepts into it,” Deleume said. The hardware has a modular architecture to allow the addition of new modules or upgrading of existing modules, while keeping the same interface, reducing the likelihood of configuration problems.

On the fast tracs
Before actual flight testing, Dassault extensively used a Honeywell-built development tool called tracs (tool for rapid advanced cockpit simulation), a ground-based demonstrator. Pilots from the ranks of Falcon customers, Air France and Airbus were involved in EASy development through tracs simulation. Airbus pilots have flown the Falcon 900EX EASy testbed.

“We also invited FAA and JAA people early in the design process, since we wanted to be sure what we were thinking of was certifiable,” Deleume said. As early as 1999, FAA and JAA certification pilots flew together for the first time on Honeywell’s purpose-modified Citation III, which features two cockpit displays, a CCD and a multifunction keyboard.

Four 14.1-in. LCD displays in a “T” layout provide twice the surface area of the baseline Falcon 900EX, equivalent to that of the Boeing 777,” Deleume said.

To increase dispatch reliability, the aircraft can depart with one EASy display inoperative. The pilot can move the inoperative display and exchange it with another so that the upper bar of the “T” is working. The information that was displayed on the inoperative screen can be transferred to the remaining LCDs. Alternatively, the aircraft can carry a spare screen to swap out should a failure occur. In case of a further failure in flight, “you can still fly the aircraft with two LCDs,” Deleume said.

Down to a “T”
He summarized the development of the “T” layout: “When we started the design of the flight deck, we wanted to put all four screens in line, because this made pilots keep their heads up. But above all we wanted to stop making a left- and right-side cockpit, so we designed this layout, where the two screens in the middle are a common workspace.” Short-term information is displayed on the two primary display units (PDUs) in front of each pilot, whereas longer-term information, such as the navigation map and system synoptic views, is displayed on the central screens. “We have not invented crew coordination, we are just facilitating it,” Bonneville pointed out.

EASy controls are also located between the pilots on the central pedestal. The CCD features a large handgrip with buttons on each side and the trackball facing forward. “We chose to have two buttons to have the same part number for the left and the right CCD and for redundancy,” Deleume explained. A knob next to the CCD can by used to scroll through various menus or to tune radios.

An alphanumeric keypad can be used as another way to enter waypoints. The multifunction keyboard (MKB) also includes shortcut buttons to functions such as EGPWS terrain inhibit, squawk identification or “direct to” commands. At the beginning “we thought that the pilots should use the graphic interface for everything,” Deleume said, but the shortcuts were added after extensive tests on the tracs simulator. A small readout allows the pilot to keep his eyes on the MKB while typing.

Each display can be divided into four windows, much like a PC. The trackballs allow each pilot to move his individual cursor, a large crosshair, among three of the displays (but not to the other pilot’s PDU). The cursor slides seamlessly from one screen to the next, allowing the pilot to look forward at the displays, rather than down at an FMS screen. When both cursors are in the same display, only the moving one is active. General and contextual menus allow access to user-friendly FMS functions. The pilot can use either the waypoint list or the digital map to create the flight plan. “For software reliability reasons, Honeywell could offer only three sizes of characters,” Deleume said.

In a radical move, Dassault has eliminated the FMS control display unit. It is replaced by the aforementioned Windows-like graphical interface. By removing the possibility of having each pilot programming the FMS located on his side of the cockpit, “we ensure they are making the same flight at the same time,” Deleume noted. This also eliminates situations where both pilots are working on their FMS, in a head-down attitude, while in a critical phase of flight.

Five phases are available for flight plans: before departure; takeoff and climb; cruise; descent and landing; and after arrival. “We studied how pilots plan their flights and
saw that they work by phase,” Deleume said.

The fifth phase allows the pilot to fill in a maintenance form.

Terrain, weather and TCAS information can be displayed on the same map, in addition to flight-plan details. A vertical situation display is available to show possible interference between terrain and the flight path. The map can be oriented north or by aircraft heading.

“Our navigation interface frees the pilot from having to imagine the situation, since he actually sees it; the pilot can therefore concentrate on flight management and decision-making,” Deleume pointed out. In the near future the EASy flight deck should be compatible with Jeppesen’s electronic flight bag. However, this will not be part of the initial certification, Deleume told AIN.

The PDU includes the ADI (attitude direction indicator), the HSI (horizontal situation display), engine instruments and the CAS (crew alerting system). The position of the slats is indicated by a slat symbol when deployed or the word “clean” when retracted. Similarly, three downward-oriented arrows indicate the gear is down, while “gear up” appears when they are retracted. All these indications disappear above 18,000 ft, which illustrates the effort to declutter the displays. On the PDU, the only portion of the screen the pilot can personalize is a one-sixth lower-right portion.

HUD-like Symbology
Dassault engineers have emulated head-up display (HUD) symbology on the ADI (HUD is optional on the Falcon 900EX EASy). Instead of the attitude symbol, the pilot follows a flight path vector (FPV) symbol, “which is much more intuitive,” Deleume contended. The FPV and an energy cue also accompany the usual indications. Dassault is currently weighing the pros and the cons of having the HUD as standard equipment, as well as having a HUD for each pilot.

On the flight guidance controller (located just under the windshield), readouts are available so the pilot can keep his head up. “In EASy’s early design, pilots had to look at the main displays while turning the knob, but this introduced errors,” Deleume explained.

The EASy software should evolve further by the end of the certification program; the first flight used EASy v6, and the certification should be done using v10. “To get final validation, every new software version is bench-tested by Honeywell in Phoenix and finally bench-tested in our flight-test center in Istres,” Deleume added. Any evolution of the certified software will have to be certified–by “paper certification” if it implies minor changes or via flight tests for more involved modifications.

“Some details in the software can be seen as relatively heavy to use or to read in normal circumstances, but they avoid any loss of information in case of a failure,” Deleume pointed out. For instance, “activate/undo/cancel” buttons displayed both on the map and the waypoint list appear redundant in normal use, but they make it easier for the pilot in case of a display failure, when the information is rearranged on the remaining screens.

The status of the fuel or hydraulic systems, for example, can be shown on the central screens through synoptic views. Systems are controlled through the overhead panel, which has been designed under the “dark panel” philosophy, all buttons being dark when all systems are in their normal configuration.

The standby electronic instrument display is not a new design, except the reference is the flight-path vector instead of the attitude. “This is an input from the JAA and FAA,” Deleume told AIN. The initial standby instrument used the attitude reference, but certification pilots objected that this was not consistent with the primary flight display.

Aircraft maintenance data is centralized, which means all system maintenance information is accessible from one point. The mechanic can either use a laptop or print the maintenance information displayed on the screen (a printer is available as an option).

Interfacing Challenges
Another problem Dassault had in mind when designing EASy as an integrated flight deck was the difficulty of interfacing a piece of equipment with the rest of the flight deck. This happened on the Falcon 2000, when the customer could choose among three different flight management systems. Dassault engineers, therefore, had a few problems with displaying information on the Collins EFIS. Some customers even got a heterogeneous fleet after Dassault elected to offer only the Collins FMS. The integrated avionics suite solves the problem, Bonneville said.

Another benefit of the new flight deck can be found in the aircraft’s nose section. Since the EASy hardware is smaller than current-generation avionics systems, it creates more room for any additional equipment.

The EASy flight deck will be the same in the 900EX, the under-development Falcon 7X and the Falcon 2000EX (although the first 32 Falcon 2000Exs will have a conventional cockpit). The Falcon 2000EX EASy should make its first flight early this year. Dassault believes cockpit commonality is good for safety and for making Falcon customers’ fleets as homogeneous as possible. Dassault plans to bring to the NBAA Convention next fall an EASy simulator that will reproduce the 7X environment, which includes fly-by-wire sidesticks.

The in-production Falcon 900C and the Falcon 2000 will keep their conventional flight decks. Although the Falcon 50EX’s cockpit could accommodate a three-screen EASy flight deck, Dassault has dropped such an idea for its smallest jet, for now.

Surprisingly, Dassault has not patented the EASy flight deck. “You cannot protect such a concept; the smallest change to the man-machine interface can make it a different system, from a legal point of view,” Deleume noted. In addition, should EASy inspire other flight decks, it will be a positive move toward cockpit standardization and thus added safety, he concluded.

Falcon 900EX EASy Features Additional Reengineering

In addition to the EASy cockpit, the new version of the Falcon 900EX features upgraded pressurization, braking, fuel and oxygen systems. These system redesigns are distinct from the flight-deck development–Dassault just took the opportunity to simultaneously improve some systems, according to a Falcon program manager. Included in the reengineering is a more automated engine start. In this regard, “we were behind some other aircraft manufacturers such as Bombardier with the Global Express,” Falcon chief test pilot Philippe Deleume conceded.