ad

Tuesday, January 5, 2010

Falcon 7x



This year’s Paris Air Show at Le Bourget provided an opportunity for me to see Dassault’s new Falcon 7X up close before I got my chance at the left seat, alongside Dassault 26-year veteran senior test pilot Yves (Bill) Kerherve, who has since retired from the company. A former French Navy fighter pilot, Kerherve flew the ultra-quiet 7X through a series of maneuvers for the crowd on the opening day of the show. Although the 7X is a large-cabin business aircraft, its maneuverability made it clear that Dassault designers had not forgotten the Mirage and Rafale fighters that came before.

While the flight demonstration itself would probably not convince anyone to write a check on the spot for a 7X, my guess is that after watching those 86-foot-span wings carry the 7X through some incredibly tight turns with ease, people would take a closer look. Dassault currently has orders for more than 165 copies of the recently certified, $40.6 million aircraft. The company is currently building three a month, and the next delivery slot is late 2011 or early 2012.

Kerherve said most of the initial orders for the 7X are from current Falcon customers, with just a few from Gulfstream and Challenger owners.

Pilots new to the 7X complete a 26-day course before being awarded a type rating. I did not have the luxury of those weeks of book and simulator time before the flight, which had been arranged just a few days before my arrival in Paris. Nonetheless, I jumped at the chance to fly the airplane the 387 nm from Le Bourget to the flight-test facility at Marseilles on the opening afternoon of the show, especially since there was the possibility of some en route airwork.

I flew airframe number 1, registered as F-WFBW, which was not a production airplane. The cabin was unfinished and cluttered with a variety of test equipment and ballast tanks that would prevent a true check of cabin noise level at altitude. From an avionics and flying standpoint, however, airframe number 1 was as representative of the 7X as S/N 4, the aircraft that sat on the static line at Le Bourget awaiting delivery to Dassault chairman emeritus Serge Dassault.

I approached the flight with some personal perspectives that bear mentioning as well. I have not flown competing aircraft such as the $29.85 million G350, which offers approximately the same payload, or the $37 million Global 5000. Before the June 18 flight in the 7X, I had never flown an aircraft with a sidestick or fly-by-wire controls. I also had no experience with the Primus Epic EASy flight deck, which, as it turned out, was actually an advantage since there was relatively little to unlearn.

From a technical aspect, I was curious about flying an airplane that had no pilot-controlled trim option–no wheel, no switch. All trim is handled by the computers, which means the stick would essentially not show or feed back any movement to the pilot during flight.

Dimensionally, the 7X resembles the Gulfstream G350 and Global 5000. Gulfstream says the G350’s maximum payload is 6,300 pounds, and Bombardier publishes 5,170 pounds for the Global 5000. Dassault pegs the 7X’s max payload at 6,000 pounds. The interior of the 7X cabin is 39 feet long, compared with the Global 5000’s 42.5 feet and the G350’s 45 feet.

Certainly any aircraft is a blend of capabilities, but range is one area where the 7X surpasses its competitors; the French airplane can fly a shade under 6,000 nm with eight people in the back. You’d need a G550 (which costs $47.59 million) to fly a similar distance nonstop. The G350’s range is 3,800 nm with a similar load. The Global XRS has roughly the same range as a 7X and a larger cabin but retails for about the same price as the G550.

The issue really becomes how far do you need to carry how many people? And how much are you willing to pay for speed? The 7X is fast. Dassault calls it a Mach 0.90 aircraft, which means the airplane offers performance similar to that of the Citation X but with a much larger cabin and far greater range. But the Globals and the Gulfstreams are no slowpokes either. The Global 5000 and the G550 offer a top speed of Mach 0.89, while the Gulfstream G350 can fly at Mach 0.88.

Simplifying the Walkaround
Approaching the 7X at Le Bourget, I conducted a preflight with Dassault pilot and senior examiner David Bronn. He mentioned that 7X pilots need be concerned about only a few items during the walkaround, which can easily be accomplished in less than 10 minutes.

Bronn explained there is no tolerance for any sort of hydraulic fluid leaks–no matter how tiny–during the preflight, just as there is zero tolerance for any tire wear that appears somewhat uneven. The 7X is also the first Falcon to have gear pins, three of them, that must be removed before flight.

Another distinction relates to the airplane’s fly-by-wire controls. There is no need to flop the control surfaces during the preflight. Dassault recommends that pilots inspect them and not move them at all during the walkaround. Static wicks are always an issue on high-altitude airplanes, and the 7X is no different in that respect. No more than two can be missing around the entire airplane and no more than one on any control surface.

A quick look in the hellhole shows pilots the steam-gauge redundancies of everything they see in the cockpit once on board. The only reason anyone might stand up in there is to disconnect the battery when the aircraft is parked, something Dassault highly recommends. The pilot will quickly find himself staring at something that appears to have been left over from the dark ages, the door to a ram-air turbine (RAT). If all three alternators on the 7X should fail, the RAT door opens to spin up enough juice to run many of the onboard systems. The APU alternator is not available in flight. The 7X also employs two separate independent power sources to supply the fly-by-wire system in an emergency.

Smart Avionics
The APU was already running as the ground crew prepared for our afternoon departure from the Dassault Falcon Service ramp at Le Bourget. Dominique Chenevier, another senior Dassault pilot, was in the jumpseat. The avionics were already on as Kerherve offered me the left seat and explained the Epic EASy trackball system and the 7X’s complete lack of steering tiller. The cockpit seats seemed comfortable, and Kerherve said the seats in the production model are considerably more plush.

The four 10- by 13-inch screens of the Epic EASy system aboard the 7X allow for only a single FMS at a time to be used to prevent one pilot from programming something about which the other pilot has no knowledge. In addition, the Epic EASy system does not allow one pilot to make changes to the flight display of the other without confirmation from the other pilot.

Each pilot has a primary flight display that also includes all engine operating dynamics. The display sits just beneath the visor, requiring only a minor tilt of the head downward to see. The center panel just below the visor is the primary navigation display, and the screen beneath that is for systems.

Although I did not have an opportunity to evaluate the head-up display on this flight, all of the HUD guidance vector symbology was available on the primary flight display, including flight path in green and thrust vectors in red, a layout designed to minimize reaction time about where the thrust levers need to be positioned for any given configuration.

The trackball allows either pilot to update all portions of the displays–the primary flight display, central navigation panel or systems panel–for information in what appears to be a Windows-like environment. The trackball housing is positioned exactly where a pilot might rest his inside hand during flight, making it also easy to find by feel.

Before-start checks and programming the FMS were traditional, as were the engine starts themselves. All three of the 6,400-pound-thrust Pratt & Whitney Canada PW307As are fadec-controlled, which means pilot interaction is minimal, requiring only that the pilot move a fuel lever during spool-up. Pitot heat and windshield heat come on automatically once two engines are running, which makes for essentially no items at takeoff.

We started the center engine first, then the right (number three) and finally the left. Outside air temperature in Paris was 24 degrees C (75.2 degrees F), and the aircraft was light at about 49,000 pounds, or about 20,000 pounds below gross with 8,000 pounds of fuel on board. The FMS of later production aircraft automatically calculates landing and takeoff data, but this particular airplane was not yet equipped to do the math, so Kerherve handled that task manually on this flight. The final check before taxi was for the fly-by-wire system, which happened with a click of the mouse.

Kerherve said we’d need about 3,500 feet of runway for takeoff, with speeds of V1 99, Vr 107 and V2 111 for takeoff on 8,700-foot Runway 21 with flaps set to two. All takeoffs and landings are conducted with the leading-edge slats extended. Kerherve gave me the takeoff briefing before we taxied out. “When I call rotate, pull the stick back gently until you see the pitch of the nose in a position where you are comfortable and simply release the stick. Never push.” That was the end of the briefing. He added that it would probably take me no more than 10 seconds to get used to the sidestick control.

For taxi, there is no tiller. With the aircraft pointed east after the engine starts, I pushed the left rudder to the floor and released the parking brake. As light as the airplane was, it began to roll ahead with no advance in the throttles. The rudders are sensitive at first but more so if the pilot does not keep his feet high enough on the pedals. The 7X soon became a docile airplane to taxi.

There are no memory items in the 7X except to don an oxygen mask in case of decompression or fire. The only confirmation needed before the takeoff roll was to verify that all sensor information was coming from the left side.

FBW Makes for a Smooth Flight
On takeoff we’d be restricted to 7,000 feet headed southwest out of Paris. We experienced no delay in takeoff as we reached the runway. The takeoff run was short–12 seconds to reach V1 and less than 10 more until the gear was in transit. While I wanted to believe the smooth roll down the runway was all my doing, my guess is the 7X nosewheel steering through the rudders was tuned precisely and produced a smooth run from brake release to rotation.

It was an odd feeling to pull the stick gently back at rotation and then release it when the nose of the aircraft was barely 20 feet in the air. But the fly-by-wire was as smooth as silk, and following the flight path vector that Kerherve had programmed for the SID was easy as I continued to fly by hand.Out of 3,000 feet the 7X was straining to fly faster as I held it to 250 knots. As someone who spent most of his career flying aircraft with control wheels, I commented to Kerherve that I felt my hands should be doing something. I felt no pitch changes on departure as first the flaps and then the leading-edge slats were retracted. But there was little to do other than a few very light movements on the sidestick. As Kerherve had predicted, it took only a short time to get used to it. I want one from now on.

The sidestick is a revolutionary style of flying an airplane unless, of course, the pilot has considerable time with Microsoft Flight Simulator. This flight made it clear that Flight Simulator time would not be wasted. Sidesticks allow a pilot to rest his left forearm comfortably on a cushioned pad and quickly learn to control the aircraft with minor movements of the wrist. As I would later see, flying the aircraft in a very nose-high attitude becomes clearly more difficult, with the strain on the pilot’s wrist sending a clearer signal of trouble than the ache of a bicep pulling back on a control wheel.

All altitude restrictions fell before we ever reached them, and I wondered if Kerherve had used some of that French pilot charm on the controllers to pave the way ahead. Climbing through 18,000 feet at 300 knots, I was reminded how much difficulty I had had understanding the French controllers while taxiing at Le Bourget. “Controllers here speak a sort of Franglish, a French-English combination,” Kerherve said, trying to set my mind at ease about a flight he’d probably made a thousand times.

Short-term information was delivered graphically to my display, with slightly more medium-term information such as flight plan data shown on the center display.

We did almost no keyboard typing, allowing me to focus my eyes where they should be–out the window. We continued to climb to FL390, which took about 15 minutes, and I watched the airplane accelerate to Mach 0.89. The maximum ceiling is 51,000 feet, at which the cabin altitude is 6,000 feet. At FL390 the cabin remains below 4,000 feet. Level at FL390 I took off the headset, and even though the airplane had no production interior the noise in the cockpit seemed quite tolerable.On the way to Marseilles we set in the frequency for the special flight-test area ATC that Dassault had set up for its operations. We’d ask them for a block of airspace to conduct some airwork before heading to Istres, a military base that also doubles as the flight-test center for Dassault.

Along the way, we spoke about a noticeable lack of circuit breakers in the 7X. There are essentially none. Nothing can be reset in flight, either. The designers did not want pilots trying to get mixed up with bits they had little or no knowledge of.
By this point in the flight, I was beginning to feel that the 7X and the Epic EASy system had a much better idea of how to fly the airplane than I did. All I needed to do was watch and jump in if something looked amiss. It was indeed an odd sensation.

The trip to Istres at Mach 0.89 was short, and we were soon beginning our descent. There was no descent checklist to perform for the 7X as we approached. Destination weather was VFR with some light rain. The plan was to try some slow flight, steep turns and configuration changes before landing. Kerherve explained that in slow flight, the 7X would not let the pilot fly into a stall. We would first see the amber low-speed cue and finally the red tape, but we would not be able to fly into the red. The pilot can bypass the computer in roll but not in pitch.

Low-speed Airwork

With the autothrottle now off, I retarded the power and extended the speed brakes to slow the airplane, which now weighed in at about 46,000 pounds. The 7X’s response to my switching off the autopilot was interesting. The sidestick vibrated,
a cue that I was now flying the airplane. The 7X responded quickly and we soon slowed through 180 knots hand flying the airplane. I took no action anywhere in the process because there was no noticeable pitch change.

Once I began my first steep turn, I put the flight-path vector on the horizon and released the stick as the bank reached the 30-degree mark. The Falcon held the turn perfectly all by itself and with the autopilot turned off. I pulled the power back to idle and listened as the warning system yelled again in a way that was impossible to miss, “Increase speed.” There were no pitch changes as I applied power and climbed out of the approaching stall.

I tried another with flaps at the first notch and slats down again with the power at idle. As the aircraft neared 102 knots, the system again yelled at me. Noticeable back pressure was required to hold the 7X in an attitude nose-high enough to slow it to this speed, something I also believe would be difficult to ignore. We tried it again at full flaps and with the gear down. The airplane was still controllable down to 83 knots, at which I put it into a succession of 30-degree banks.

After stowing the gear and flaps, I accelerated the aircraft to 250 knots to try some steeper turns. At 250 knots and less than 35 degrees I again was able to release the stick and the 7X would hold the bank. At more than a 35-degree bank I needed to hold the stick back. If I released the sidestick in a 50-degree bank, the aircraft righted itself to 35 degrees. There is no limit to the bank angle in the 7X–pitch yes, bank angle no.

Approaching Istres, we descended through 4,000 feet and had an opportunity to see the TCAS in action as VFR traffic appeared out of nowhere. Initially at 400 below us, it climbed to our altitude as we began to search. The “traffic” announcement quickly switched to “descend, descend.” I complied quickly and turned away as the traffic disappeared over us unseen. Without TCAS, it would have been close despite the good visibility outside.

We eventually headed back to Istres, and the tower sequenced us behind a landing C-130. With 185 knots still on the airspeed indicator, I reduced the power to idle as Kerherve lowered the gear and flaps and I was quickly down to 120 and easily slowing behind the C-130. Ref speed would be 111 knots. The 7X seemed to find a landing power slot easily, and I made small changes with the throttles until the flare.

I retarded the throttles at 40 feet and increased nose pitch only slightly. On touchdown, the trailing-link gear made me look good, with an incredibly smooth landing as I pulled the center reverser handle back. We were so slow at touchdown, however, that by the time the bucket came out–probably six seconds–we were already slowing through 70 knots. The brake-by-wire on the 7X is highly effective and I easily used no more than about 2,500 feet to the turnoff.

We taxied to the Dassault ramp and shut down. We had used about 4,000 pounds of fuel during the 1.6-hour flight. Kerherve said that with the 3,900 pounds of fuel remaining, we could easily have landed in Rome or returned to Paris with a reserve since the 7X burns about 2,000 pounds per hour total when it’s light. With full fuel on board, the 7X can routinely fly from Paris to Cape Town, South Africa; or Paris to Tokyo; or New York to Dubai nonstop.

For a large aircraft, the 7X is incredibly easy to fly. The sidestick was something I quickly learned to enjoy, as well. A strong point on this aircraft is how little time I spent with my head inside the cockpit because so much necessary information was available almost within my peripheral vision or with only the slightest downward tilt of my head. This is what we should all be doing in any airplane.

Pilots of the 7X will learn quickly to fly with their fingertips rather than with their hands because the aircraft is that light on the controls. Indeed, the systems that control the 7X may be technologically complex, but from a control input perspective they are as light as on a small aircraft.

The immediate question might well be whether or not the 7X is worth the wait. From the perspective of a pilot who had only a few hours of exposure to the aircraft, I’d have to say absolutely

No comments:

Post a Comment