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The Embraer E195-E2 is powered by two Pratt & Whitney PW1900G geared turbofan engines with a 73-inch (190 cm) fan diameter and a 12:1 bypass ratio. The fan is approximately 21 inches (53 cm) wider than the General Electric CF34-10E it replaced on the first-generation E195. Fitting an engine that large under the wing of a regional jet that sits close to the ground required Embraer to redesign the wing, the landing gear, and the gear retraction system around the engine rather than simply bolting a bigger powerplant onto the existing airframe.
The solution involved bending the inboard wing upward into a gull shape to raise the engine pylons, designing landing gear 20 inches (51 cm) taller than the E1’s, and engineering three separate bespoke wings for the three E2 variants rather than sharing a single wing across the family. The E195-E2’s wing has one of the highest aspect ratios of any aircraft in its class, with raked wingtips instead of winglets and a wingspan of 115 feet (35.1 meters) that is only 2.3 feet (0.7 meters) shorter than the much larger A320neo.
Fitting A 73-Inch Fan Under A Regional Jet’s Wing
The first-generation Embraer E195 was powered by two General Electric CF34-10E turbofan engines with a fan diameter of approximately 52 inches (132 cm) and a bypass ratio of roughly 5.4:1. The engines fit comfortably under the E195’s low-mounted wing with standard-length landing gear and conventional pylons. When Embraer launched the E2 program in 2013, it selected the Pratt & Whitney PW1900G geared turbofan as the sole engine option across all three variants. The PW1900G has a fan diameter of 73 inches (190 cm) and produces up to 23,000 lb (102 kN) of thrust on the E195-E2. The fan is approximately 21 inches (53 cm) wider than the CF34 it replaced.
Embraer Senior Vice President of Engineering Luis Carlos Affonso described the engines as “extremely large for the size of the aircraft” in an interview with Simple Flying. The size was deliberate. A larger fan moves a greater mass of air per revolution at a lower velocity, which produces thrust more efficiently and more quietly than a smaller fan spinning faster. The PW1900G’s 12:1 bypass ratio, meaning twelve parts of air flow around the core for every one part that enters it, is more than double the CF34’s approximately 5.4:1 ratio. The efficiency and noise benefits of the bigger fan were central to the E2’s design objectives of 25% lower fuel consumption per seat and the lowest noise signature of any narrowbody jet in production.
The problem was fitting the engine under the wing. The E195’s fuselage sits close to the ground. The original landing gear height and wing position provided clearance for a 52-inch engine without difficulty. A 73-inch engine in the same position would sit too close to the runway surface for safe operation, particularly during rotation on takeoff when the aircraft’s nose pitches up and the tail and engine nacelles move closer to the ground. Embraer could not simply bolt a larger engine onto the existing wing and gear. The airframe had to be redesigned around the engine, and that redesign touched the wing shape, the landing gear height, the horizontal stabilizer, and the gear retraction mechanism.
What A 12:1 Bypass Ratio Means And Why It Matters
A turbofan engine produces thrust by accelerating air backward. The air follows two paths. A small portion enters the engine core, where it is compressed, mixed with fuel, ignited, and expelled through the turbine and exhaust nozzle at high velocity. The larger portion bypasses the core entirely, flowing through the fan duct around the outside of the engine and exiting at the rear at a lower velocity. The bypass ratio describes the proportion between these two airflows. At 12:1, the PW1900G moves twelve units of air through the bypass duct for every one unit that passes through the core.
The physics favoring a high bypass ratio comes down to propulsive efficiency. Thrust is the product of mass flow rate and velocity change. An engine can produce a given amount of thrust either by accelerating a small mass of air to high velocity or by accelerating a large mass of air to low velocity. The second method is more efficient because the kinetic energy wasted in the exhaust, which is proportional to the square of the velocity, is lower when the exhaust velocity is lower. A 12:1 bypass ratio engine moves substantially more total air than a 5:1 engine at the same thrust level, but the air leaving the bypass duct is moving slower. Less energy is wasted in the exhaust. More of the fuel’s energy goes into propelling the aircraft forward.
The geared turbofan architecture is what makes a 12:1 bypass ratio practical in an engine of this size. In a conventional turbofan, the fan is connected directly to the low-pressure turbine and both spin at the same rotational speed. A larger fan operates most efficiently at a slower rotational speed than the turbine that drives it, which means a direct connection forces a compromise: either the fan spins faster than optimal or the turbine spins slower.
The PW1900G’s reduction gearbox breaks that link. The turbine spins at its optimal high speed while the gearbox reduces the rotational speed delivered to the fan by a ratio of approximately 3:1. The fan turns slowly for maximum efficiency and minimum noise. The turbine turns fast for maximum power extraction. The gearbox is the component that allows both to operate at their respective optimums simultaneously, which is why the PW1900G achieves its bypass ratio, fuel efficiency, and noise levels in a package that the CF34’s direct-drive architecture could not match.
The Gull Wing That Solved The Ground Clearance Problem
Embraer’s solution to the ground clearance problem was to bend the wing. The inboard section of the E2’s wing angles upward from the fuselage before transitioning to the conventional dihedral of the outboard section, creating a subtle gull wing shape that is visible when the aircraft is viewed from the front. The upward bend raises the engine pylon attachment point relative to the fuselage by several inches, which lifts the bottom of the 73-inch nacelle further from the runway surface without changing the fuselage height or the overall wing geometry outboard of the engine. Embraer engineers confirmed that the gull wing was required specifically to provide enough ground clearance for the PW1900G.
The alternative approaches each carried penalties that Embraer wanted to avoid. Lengthening the landing gear alone would have added weight and required a deeper wheel well, consuming cabin or cargo volume inside the fuselage. Mounting the engines further outboard on the wing would have changed the wing’s structural loading and flutter characteristics, requiring a heavier wing spar to handle the altered bending moments. Moving the wing higher on the fuselage would have changed the aircraft’s aerodynamic characteristics and passenger cabin layout.
The gull wing achieved the necessary clearance with minimal impact on the rest of the airframe design. The inboard bend is subtle enough that most passengers do not notice it. From the ramp, the most visible clue is that the engine nacelles appear to hang slightly higher relative to the fuselage than on competing regional jets with smaller engines.
The gull wing is not unique to the E2 in aviation history. The most famous gull wing designs include the Vought F4U Corsair fighter of the Second World War and the Polish PZL P.11 of the 1930s, both of which used the configuration for propeller clearance rather than jet engine clearance. On the E2, the engineering rationale is the same: creating vertical space between the ground and a component that would otherwise be too close to the surface. The execution is more subtle than the Corsair’s dramatic inverted gull, but the underlying problem is identical. The airframe had to accommodate a propulsion system that was physically too large for the space available in a conventional wing-to-ground geometry.
Landing Gear 20 Inches Taller Than The E1
The gull wing raised the engine, but it did not provide enough clearance on its own. Embraer also designed new landing gear for the E2 that stands 20 inches (51 cm) taller than the E1’s gear. The combined effect of the gull wing and the taller gear gives the PW1900G the ground clearance it needs during all phases of ground operation, including the rotation at takeoff when the nose pitches up and the geometry between the engine nacelle and the runway surface reaches its tightest point. The E2 sits visibly higher on the ramp than the E1. Ground crew, jetbridge operators, and catering truck drivers who work both types notice the difference immediately.
The taller gear uses a trailing-link design, where the axle is mounted on an arm that trails behind the main strut and pivots upward on landing to absorb the touchdown energy. Trailing-link gear produces softer landings than conventional telescoping struts because the pivoting arm provides a longer stroke over which the landing energy is dissipated. The E1 also used trailing-link gear, but the E2’s version is structurally redesigned to handle the higher loads that the taller configuration produces during landing and ground maneuvering. The gear retracts fully behind fuselage-mounted doors rather than into pods or fairings on the nacelle or wing, which eliminates the aerodynamic drag that external gear fairings produce. Embraer estimates that the clean retraction behind flush doors reduces fuel consumption by approximately 1% compared to a configuration with exposed gear pods.
The 20-inch height increase created secondary effects across the aircraft. The jetbridge interface height changed, which affects how the aircraft connects to terminal gates. The center of gravity sits higher relative to the ground, which changes the aircraft’s ground handling characteristics in crosswinds and during taxi. The cargo hold door positions shifted relative to standard ground handling equipment heights. Each of these changes required Embraer to verify that the E2 remained compatible with the airport infrastructure and ground support equipment that airlines and airports already operate. An aircraft that requires unique ground equipment at every station it serves is an aircraft that airlines will not buy, regardless of how efficient it is in the air.
