Embraer also beefed up the wings, replacing the tips with detachable winglets (instead of blended units) and strengthening the flap panels and actuators for higher full-flap speeds and increased Vmo. All of this, while not technically necessary to accommodate the added fuel capacity, adds utility and versatility and makes descents quicker, saving precious minutes in the arrival process.
Higher arrival speeds mean the potential for greater bird strike damage, so the 650 got a new windshield with glass replacing the polycarbonate. The glass boasts better light transmission, less distortion and higher all-around reliability, because it’s stronger.
The higher weight of the airplane meant updating the landing gear as well, which Embraer did by going with larger, 16-inch main wheels and brakes, as well as what it calls a “recalibration” of the nose gear strut to accommodate the change to the main gear. Interestingly, the 650 is officially five inches shorter in height than the 600, because of its greater weight.
Speaking of weight, the 650, it goes without saying, has a higher maximum takeoff weight (53,572 pounds) than the Legacy 600 (49,604 pounds). Still, the 650 boasts a much greater full-fuel payload than the 600, 1,910 pounds, more than 400 pounds greater. This gives the 650 the ability to carry as many as nine passengers with full fuel, a remarkable capability for a long-range airplane.
Despite this newfound power, the improved engines add up to very similar fuel burns for similar missions. On a typical 1,000 nm mission, for instance, the 650 uses around 3 gallons more total than the 600 does. Indeed, the direct operating costs for the two airplanes, as determined by Embraer, are almost identical.
Coming up with an additional 500 nm of range can’t be done just by adding more fuel, because the fuel adds weight, which requires stronger structure, which adds weight too, and weight cuts down on range. So you need to economize elsewhere, and in this case it was with new, more powerful and more fuel-efficient engines in the form of the Rolls-Royce AE 3007A2.
While they are close derivatives of the AE 3007A1E engines that power the Legacy 600, the Rolls-Royce AE 3007A2 engines on the 650 are a crucial piece of the puzzle. Embraer refers to the new turbofans as “refinements” of the previous models; if so, they are impressive refinements. The new turbofans feature full authority digital engine control, or fadec, and they are more fuel efficient thanks to a next-gen fan, cutting-edge fadec software and a pilot interface that makes it easy to economize. And they do all this while increasing thrust by more than 1,000 pounds per side.
The key to the new engine is a new fan, which uses blades with a wider chord and more contoured leading edge, as well as subtly changed fan spinner and bypass vanes. The wider chord means fewer blades; if you had the inclination, you could count them. There are 22, compared with 24 blades on the previous engine.