Embraer’s first VLJ made its maiden flight at the end of Jul 2007, and has since been joined by 2 more flying prototypes. Number 4, now in final assembly, will join them for more flight testing and systems integration before final certification. Deliveries start in the 2nd half of 2008.
Pro Pilot interviewed some of the Phenom 100 program’s drivers to understand the design philosophy that an airliner builder brings to the small-ship end of the business jet market.
It was only recently that Embraer decided to enter this market sector. Exec VP, Executive Jets Luis Carlos Affonso explains, “In 2005, we made the strategic decision to address business aviation. Our strategic intent is to grow the [executive jet] business unit and transform it into a strong business unit within Embraer.” He continues, “We have a strong ERJ145 family and E-Jet [Embraer 170/190] family, and we had a very positive experience with the Legacy.”
Affonso adds that Embraer focused on the VLJ as, with a small airplane, it would reach a large number of customers—then it would construct a solid customer base which it could expand by offering bigger airplanes to encourage Embraer brand loyalty. He sums up, “We decided that our positioning was to be ‘best in class’—the biggest VLJ, with the largest cabin and a good cross-section.” Other key factors, “even in the VLJ market,” are an enclosed lav in the right place (in the back of the airplane), with the option of a rigid door. The sales hook, he says, is that “our cabin is virtually identical to the cabin of a light jet, yet it costs .5 million less.”
Embraer wants the cabin to be the focus of the “emotional experience.” Instead of a cylindrical cross-section, it is more oval—BMW DesignWorksUSA was enlisted to provide the relaxing and comforting feeling of a luxury car.
Although the Phenoms (the 100 and the larger 300, scheduled a year behind in development) are not intended to be flown by weekend warriors with little experience and a quick transition from a light piston single, Embraer has designed them from the outset around single-pilot operation consistent with its stated goal of high availability. Thus the Phenom (compared to performance-equivalent light jets and VLJs) has a “low-stress pilot interface.”
Drawing on its experience with the E-Jet family, Embraer is planning an unprecedented level of integration in the man/machine interface, even though they may be using the same avionics platforms as some competitors. Not that an Embraer 170 pilot will immediately feel right at home in a Phenom 100, but Affonso emphasizes that “stringent requirements and goals resulted in a design that is ‘human-factors-centric,’ with a very low workload. Compare, for instance, our checklist—the before-engine-start checklist for the Phenom 100—versus a current aircraft of the same class, and you move from, say, 20 tasks down to maybe 3 tasks.” And, he notes, “it’s more difficult to make a simple design than a complex one.”
Embraer is not ready to finalize numbers on some critical specifications. Henrique Langenegger, the engineer responsible for the Phenom program, explains, “We look at weight as an intermediate variable. We want to reach the speeds, the range, the takeoff and landing field lengths, and the payload. Weight varies during development, and we avoid putting out numbers when they can change.”
Interestingly, passenger convenience and comfort are linked to the design of the Phenom 100’s fully automatic fuel delivery system. Langenegger says, “We have just wing tanks. With no fuselage tanks, there are no loading restrictions with any of the 3 interior seating arrangements. There are no center of gravity restrictions on any of them, so you can fly without worrying about them at all.” He adds, “We sized the horizontal tail properly. We don’t like CG restrictions—if you have restrictions, you are bound to make mistakes. Customers don’t have to care about that.”
Phenom 100’s flap system is unique in this class of airplane. It has airliner-style systems and automation levels, so pilots from bigger aircraft will feel at home as well—the same types of displays and symbologies should make handling stressful operations in the Phenom cockpit more natural.
Embraer wanted high wing loading for speed and comfort—thus the sophisticated flap system. Typical approach speed (1.3 x stall) at typical landing weight is about 93 kts. Instead of merely pivoting the flaps, they are on tracks. There are 3 basic configurations—for hot and high takeoff, for a typical takeoff at a density altitude of, say, 2000 ft, and for landing. The flaps go back a bit for takeoff, and just a little further for landing. Deflection can be varied at various track positions.
Phenom is virtually “filament-free.” Only the wing inspection lights for the icing system have traditional light bulbs. Langenegger explains, “We are designing an aircraft that can have 7–8 flights a day in air taxi operation. We cannot have failures that keep you on the ground—everything is designed to be easy to diagnose, fix or replace.
“The central maintenance computer covers avionics plus all the systems. We will be able to identify [most of] what’s going wrong without taking the airplane apart... On the Embraer E-Jets, you can identify nearly 100% of everything—on this airplane, we will also have a very good idea of what is going on. We use the same philosophy.”
Coming soon—new levels of data acquisition
According to Affonso, the Phenom 100 “already has a lot of data acquisition built in.” He continues, “We will certify it and continue to add retrofittable improvements over the years. After introduction, we will have both wi-fi and Iridium links to transmit maintenance information from the airplane in real time.” This means that pilots can get information automatically.
From the start, pilots will be able to transmit all maintenance data from the aircraft. Langenegger adds, “Later, we plan inflight transmission of selected information, so someone on the ground is ready for you [in the event of] a failure that would not allow immediate dispatch. At the beginning, the main focus is the engines—later, we will make other systems available.”
To start the airplane, explains Langenegger, the pilot flips 2 battery switches and then loads the FMS (flightplan) and sets the takeoff temperature for the FADEC. Next, he continues, the pilot turns the engine switches (one per engine) to start the engines. “Then you’re ready for takeoff,” he says. “With FADEC, you just check your N1 and push your throttles forward. No ‘Hydraulic pumps on,’ no ‘generators on’ and no avionics to set—all of that is automatic. If something goes wrong, you get a warning.”
Automation continues in flight. “After you are airborne, you go into autopilot,” says Langenegger. “In cruise, we have a cruise speed control—you set a speed and the FADEC maintains the speed, even as you burn fuel. It’s one less thing the pilot worries about.” He adds, “When you land, you taxi back, shut down—2 keys for your 2 engines, 2 battery switches off—and you can go home.”
Pressurization is fully automatic, with an 8000-ft cabin to certified ceiling (FL 410). Fuel distribution is fully automatic and uses the same basic architecture as on the ERJ145 and E-Jet families. Even after the first failure, the system shifts the load, so the pilot doesn’t have to do anything. The system provides the pilot with a status report without increasing his/her workload.
There is no autoland option on the Phenom 100—it would be too expensive for an airplane of this size, according to Langenegger. Typical switchover to hand flying is at or just above 200 ft.
Embraer says it is realistic about passenger weight and baggage requirements, and is focused on delivering guaranteed payload. “We will change other things (MTOW, etc) to deliver the promised payload,” notes Langenegger. “Weight is under control so far. We have a target number and we are very close. We are not using much of our ‘weight buffer’—so we are sure we will not have a weight overrun. We use [a conservative figure of] 205 lbs per passenger (with luggage) in calculations.”
For Embraer, says Langenegger, flight testing has been more validation than discovery. “We did a lot of wind-tunnel testing in Russia,” he says. “The quality of the airflow is very good, and they can flow at very high speed, so we can simulate real flight conditions closely.” Based on Embraer’s successful experience in 170 testing, it followed similar steps with the Phenom 100 program. Consequently, notes Langenegger, “We have a high degree of confidence in the numbers we publish.”
When Embraer moves to flight testing, he says, it’s “to see that everything is working—not to see if it will fly. We will be flying just to confirm performance and prove integration of systems.”
Market and market share
There is little agreement on how many VLJs will be flying in 10–15 years. Affonso suggests 2500 as a realistic number. If the jet air taxi goes really well, he says, Embraer predicts around 5000 at most. “We believe in the VLJ air taxi model in general,” he says, “but I think that the numbers are overstated.”
Affonso continues, “We plan on the Phenom 100 being 30% of that market—about 1000 airplanes. We are designing an airplane that appeals to the individual as well as the air taxi and charter companies. Individual owners want our man/ machine interface, performance and ease of flying—for air taxi, we add availability and we design for high utilization. Our airplane is unique in that regard—availability.”
Currently, the Phenom order book shows over 700 positions sold (for the 100 and 300 combined). This figure is divided about 50/50 between private and fleet buyers. Individually-ordered airplanes will not necessarily be owner-flown, notes Affonso. “Our Phenom 100 is the biggest airplane in the category,” he says, “and we see that the early owners are not so much owner-pilots [although] we believe that the owner-pilot will be flying the smaller airplanes.”
Affonso makes the point that while the Phenom 100 is a jet—and, naturally, “things happen faster” in a jet—its numerous features and man/machine interface design make it easier to fly than a heavy twin turboprop. He continues, “You have so much help in terms of situational awareness. In a Phenom 100, it is easier to navigate, aviate and communicate than even in some single turbines. We have small engines with low inertia, fast reaction times—they are not tricky, and they are FADEC-driven.”
That said, Embraer is considering offering a mentor pilot program. “There are big differences between flying alone and flying with a mentor pilot,” notes Affonso. Entry into service
Embraer plans first deliveries in North America for mid-2008, and in Europe 6 months later. Plans call for 45 service centers around the world by mid-2008. Embraer will set up 7 company-owned and 38 authorized service centers to serve all its bizjet types. It has also created a joint venture with CAE for training. Affonso predicts, “We will have a capable system. Operational ceiling is FL 410, even when flown single-pilot.” Flight characteristics
As of Jan 2008, the test campaign had accumulated more than 350 hours on more than 365 flights.
Langenegger describes flight program status in this way: “There were very few items that we had not anticipated. Every day we try to fly in the morning and in the afternoon. Our plan for the first few months is to explore the whole envelope and freeze the configuration. We are now very close.”
Some things can still change, of course. As Langenegger remarks, “We have had no major problems—a few small ones, but they were overcome... I don’t want to be over-optimistic, but so far, so good.”
Phenom 100 prototype number 2 flew on Sep 26, 2007. After it flew, says Langenegger, Embraer did the certification ground vibration tests [flutter tests, to determine harmonics]. “There were no surprises,” reports Langenegger. “We are now making thrust determination tests—seeing results at various altitudes and speeds—to gauge the actual performance in many dimensions.”
So far, Embraer’s test pilots have done all hand-flying. They report that the aircraft is very precise. “If you want a certain pitch, or a certain roll rate, you command the aircraft, and it does what you ask—it doesn’t overshoot or lag,” adds Langenegger.
Aircraft number 3 first flew on Dec 21. It will have a full interior, and will test noise and ultimate weights, along with other “comfort” parameters. The 4th aircraft will be fully configured, and will face a full set of rigorous weather tests. “We will expose these test aircraft to as much ‘real life’ as possible,” Langenegger says. “We don’t want the customers to have squawks.”
It’s worth asking how a test program can approximate real life. Embraer is studying ways to get input from low-time pilots in order to make the Phenom 100 as “pilot-proof” as possible. Langenegger notes, “With everything on ‘auto,’ everything is easy—but if some switch is left out of ‘auto’ position, an annunciator tells the pilot that something is not set properly. There is a lot of human factors testing, including systems and, especially, flight characteristics. Our regional aircraft are professionally-flown—the Phenom may be owner-flown, or flown by someone who is not flying very often.”
He adds, “We want to fix things now—we don’t want to have anything to fix after delivery. To make the pilots’ life easier, we try to make the airplane simple. Airplanes always have too many controls, but each one we eliminate makes the pilot’s job easier.”