Embraer Phenom 100
It takes an airline maker to produce an easy to operate and very durable entry-level business jet.
By J. Mac McClellan
Photographed by Embraer
May 2009
The entire normal operating checklist for the new Embraer Phenom 100 light business jet fits on both sides of a laminated card that you can slide into a shirt pocket. While other business jets need giant spiral-bound pages upon pages to go through before liftoff, the Phenom is designed to cut pilot workload to a minimum so there is time to focus on the overall situation while the airplane and its systems take care of themselves.
The Phenom 100 is Embraer's first from-scratch business jet, and its design reflects what the company has learned from building its very successful RJ series regional jets, and now its E-Jets in the 170 and 190 series that compete with the Boeing 737 and Airbus A320 family. The airlines demand automated and simplified systems, rugged construction, and the ability to fix failures quickly when they do occur. And you can instantly see that philosophy designed into the Phenom.
For example, the Phenom has no avionics master switch. Amazing. But if you think for a moment, why do you need an avionics master? There are no conventional gauges or instruments to look at, so the three big displays of the Garmin system that Embraer calls Prodigy must be up and working to know anything about the status of the airplane. So the entire Prodigy system comes on with the battery switches. But I still think it would be very difficult for business jet makers to make such a leap without the experience of designing a modern airline jet.
The same "if you don't need it, don't include it" philosophy prevails in the rest of the Phenom 100 cockpit. The pre-start checklist is pretty much turn on the two batteries and then rotate one of the engine control knobs to start. When the first engine starter engages, the flashing beacon -- the universal signal of engine start and operation -- automatically turns on, and stays on until the last engine is shut down. The fuel pumps, the generators and the pressurization system simply stay in the automatic mode and check themselves with no need for a separate test routine.
Embraer says the Phenom has 70 percent fewer actions on its checklist than other light jets, but it seems to me that the reduction in required steps is even greater. Some traditionalists will say that Embraer has taken the pilot out of the loop with so much simplification and automation, and I agree. But I would use the word "relieved" the pilot of the mindless and time-consuming chores of switch flipping and gauge reading when those binary tasks are what electronic systems and monitors do best. With those multiple checking steps eliminated, the pilot can focus on the critical issues, such as do I have the correct clearance, am I on the right taxiway, is this the assigned runway, and all of the other complex aspects of flying that only a human can do.
The Phenom 100 is approved for single pilot flight so the cockpit automation is even more important. Embraer's customer information indicates about 20 percent of the jets will be flown by their owners and, as with other light jets, many of those will be stepping up with little or no jet experience.
Embraer has placed the Phenom 100 right in the middle of entry-level business jets with its price tag of approximately $3.5 million. The Phenom cabin is bigger than the less costly Cessna Mustang, and very close in size to the more expensive Citation CJ1+. The Phenom's 390-knot top cruise speed is a tad faster than the CJ1+. And the maximum range of all three jets is over 1,100 nm, and in each jet the achievable range is highly dependent on the ability to climb directly to the airplane's ceiling of 41,000 feet. If air traffic control delays climb, or sends you down far from the destination, as is common in many parts of the United States, range will fall off dramatically.
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It's easy to see Embraer's Oval Lite cabin shape in the photo above, as the sidewalls extend more or less straight down from the maximum width point rather than circling back in at your feet as a normal cylindrical fuselage does.
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In addition to its advanced cockpit and simplified systems, Embraer concentrated on cabin comfort in the Phenom 100. The airplane has what the company calls an Oval Lite cabin cross section with the lower half of the fuselage tube pushed out instead of wrapping around in a constant radius as is the norm in pressurized cabins. The wider lower half of the cabin means your feet rest directly in front of you instead of being pushed in toward the center by the curving fuselage wall. The design provides space for a wide seat with plenty of room for your outboard shoulder and head to remain clear of the cabin wall. The design adds virtually nothing to the overall drag because the expanded part of the cabin blends into the wing-body fairing that needs to be there in any case.
The cabin has just 1 inch under 5-foot headroom from the dropped aisle, and is 1 inch over 5 feet wide at your elbow when seated. That is bigger than both of its Citation competitors and also more roomy than the Beech King Air cabin, which has long been a benchmark of light business airplane comfort.
Like all recently designed business jets, the Phenom fuselage sits atop the wing so no wing structure intrudes on the cabin. The wing is a unique Embraer design that combines both good low-speed characteristics and an airfoil shape that delays critical Mach to a speed above the Mach .70 maximum of the airplane. That means air accelerating to flow over the wing does not reach Mach 1 and the high drag that creates. It also means the Phenom gains very little in efficiency and range when slowing down from high-speed cruise because even at max cruise the wing is operating with low drag.
The wing flaps are very long in span, and extend far aft on tracks before deflecting down so they add a great deal of area to the wing, and open a large slot to promote smooth airflow at high angles of attack. During flight testing the company found that two wing fences on each side improved low speed lift. The fences -- sometimes called stall fences -- help to prevent spanwise airflow at high angles of attack by physically blocking the slipstream and forcing it back over the wing. Fences were once common on business jet wings, but more recently vortex generators that create a high energy wake have been used to accomplish the same goal. Embraer experimented with several styles of vortex generator devices but found the tried and true fence delivered the greatest improvement for the least weight and drag.
The Phenom 100 meets or exceeds all design goals set when the program was announced in 2005, including an increase in baggage space to a cavernous 55 cubic feet in the tailcone. It turned out that the systems required less than anticipated space so there is more room for baggage. Enough room to carry two sets of full-length skis, plus four garment bags, four roll-on suitcases and four laptop cases.
The airplane sits pretty high on its trailing-link main landing gear and the T-tail is way up there at more than 14 feet above the ramp. The horizontal tail is fixed, and dual trim tabs are used for pitch trim. The engines are also located high on the fuselage to keep them up and away from the accelerated air flowing over the wing. The fuselage inboard of the nacelles is hallowed out according to the "area rule" to reduce drag. The high engine location makes it easy to load and unload the baggage compartment without a lot of stooping and bending, but a large and easy to read sight gauge makes checking the engine oil a snap without need for a ladder.
To account for the high stance, and to ease passenger access, the Phenom has a big jet-style airstair door. The airstair has integral steps, of course, and even a handrail, something not seen in light jets. Opening and closing the door from inside or out is a simple one lever throw process, and a well-done spring balance system makes it easy to raise or lower the door.
The forward fuselage and canopy flow smoothly with full-time electrically heated windshields blending in. The shape no doubt contributes to the low noise of the cockpit. The windshield design also allows it to be replaced entirely from the outside in an hour with no need for special tools or curing of sealants. In fact, all components and sensors such as the stall warning, pitot-static, standby electric fuel pumps, and so on can be removed and replaced from outside the airplane with no special tools.
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