2 Engines Under the Wings

The two engine underwing model is the most common type of commercial aircraft in the sky today. There are two types: single-aisle, narrow body (Boeing 737, 757, Airbus A220 & A320, and Embraer E170) and two-aisle widebody (Boeing 767, 777, 787, Airbus A300, A330, and A350). There are photo examples of each type at the bottom of this page. Place your mouse over the highlighted text to see that area on the image to the right.

Background

  • The Airbus A220 entered service in 2016 with Swiss International.  It was originally developed by Bombardier as the C-Series but was sold to Airbus when Bombardier got out of the commercial airliner business.  Delta and Swiss International are the two largest operators of this type.  The A220 has a capacity of 100-150 passengers and can fly up to 3,400 miles.

  • The Embraer 170/175/and 190 models (collectively called the E-Jets) entered service in 2004 and are built in Brazil. They are basically large regional jets, seating between 70 and 100 passengers. These planes are flown under most of the regional airline brands, including Delta Connection, American Eagle, and United Express.

  • The Boeing 737 is the most popular commercial airliner ever sold. The -100 and -200 series were in production from 1968 to 1988, followed by the -300 and -500 series (all referred to as the 737 classic) from 1984 to 1999, and the “next generation” -700 through -900 series from 1998 to 2019. Production began on the new 737 Max series in 2017. More than 11,000 737s have been sold. Most major airlines in America fly the 737 except Jetblue.  737s are also used as freighters, aerial firefighters, private business jets, and in military surveillance aircraft roles.

  • Airbus introduced the narrowbody A320 family in 1988. The A318/319/320/and 321 versions are similar but have different passenger capacity and range. They are built in Europe and Alabama. The largest operator of the A320 family in the world is American Airlines with over 400.  Most airlines in the U.S. fly these aircraft except Southwest.

  • Boeing introduced the 757 and 767 in 1982. Production of the 757 ended in 2004 and the 767 is still being built as a freighter and another version as a military refueling tanker. The largest operator of the 757 is Delta Air Lines, while FedEx has the largest fleet of 767s with 85.

  • The Boeing 777 went into production in 1995 and in the U.S. only United, American, and Delta fly them. This widebody jet is primarily used for long-haul routes.

  • Boeing’s new 787 entered service in 2011. In the U.S. only American and United fly the 787, mostly on long-haul international routes.

  • The A300 was the first aircraft produced by Airbus and was built from 1974 to 2007. The only operators remaining in the U.S. are FedEx and UPS which use the freighter version. Out of the total of 823 built, 249 remain in service worldwide (A300 & A310) of which 115 are operated by FedEx and UPS.

  • Airbus introduced the widebody A330 in 1998. In the U.S., only American and Delta fly this jet for long range flights.

  • The Airbus A350 is a twin engine widebody jet that competes with the Boeing 777-300 and 787.  It entered service in 2015 and is used on long-haul international routes.  The only airline in the U.S. that flies the A350 is Delta.

What to Look For

The most obvious feature by which to identify an A220 is the unique streamlined shape of its nose & cockpit windows.  All A220s have winglets, oval shaped cabin windows, and one emergency exit over the wing.

There are two A220 versions: the A220-100 and A220-300.  The -300 is longer and will have 17 windows ahead of the emergency exit compared with 12 for the -100 version.

The most obvious feature by which to identify an A220 is the unique streamlined shape of its nose & cockpit windows All A220s have winglets, oval shaped cabin windows, and one emergency exit over the wing.

There are two A220 versions: the A220-100 and A220-300.  The -300 is longer and will have 17 windows ahead of the emergency exit compared with 12 for the -100 version.

The most obvious feature by which to identify an A220 is the unique streamlined shape of its nose & cockpit windows.  All A220s have winglets, oval shaped cabin windows, and one emergency exit over the wing.

There are two A220 versions: the A220-100 and A220-300.  The -300 is longer and will have 17 windows ahead of the emergency exit compared with 12 for the -100 version.

While these planes can be confused with other narrowbody jets from a distance, the one thing that stands out is the shape of the nose. The Embraer jet has a longer and more tapered nose, similar to that of their smaller Regional Jets, the ERJ-135/145.

The most notable visible difference between the E-170/E-175 and E-190 versions is that the 170/175 do not have an emergency exit over the wing because they are shorter, while the 190 has one over wing exit on each side.  All Embraer 170 family planes have winglets.

While these planes can be confused with other narrowbody jets from a distance, the one thing that stands out is the shape of the nose. The Embraer jet has a longer and more tapered nose, similar to that of their smaller Regional Jets, the ERJ-135/145.

The most notable visible difference between the E-170/E-175 and E-190 versions is that the 170/175 do not have an emergency exit over the wing because they are shorter, while the 190 has one over wing exit on each side.  All Embraer 170 family planes have winglets.

While these planes can be confused with other narrowbody jets from a distance, the one thing that stands out is the shape of the nose. The Embraer jet has a longer and more tapered nose , similar to that of their smaller Regional Jets, the ERJ-135/145.

The most notable visible difference between the E-170/E-175 and E-190 versions is that the 170/175 do not have an emergency exit over the wing because they are shorter, while the 190 has one over wing exit on each side.  All Embraer 170 family planes have winglets.

The Boeing 737 compares to the Airbus A320. All 737s have a dorsal fin at the base of the tail that forms an angle where it meets the fuselage, while the Airbus is straight.

The 737 variants that are in service today are the 3rd generation, comprised of the -700, -800, and -900 models, and the 4th generation, called Max7, Max8, Max9, and Max10 (all temporarily grounded worldwide as of 2020).  The older generations are rarely seen anymore.  Nearly all of the current 737s have winglets, either the blended shape or the scimitar shape, to improve fuel economy by reducing aerodynamic drag.

737-700 models can be identified by a single emergency exit over the wing, while all others have two.  The only significant difference between each model is length, with the -700 being the shortest.  The 737 Max has larger engines with chevron-shaped exhaust outlets.

When viewed from the front, the 737’s engines are not fully circular but slightly flattened on the bottom to help with ground clearance.

The Boeing 737 compares to the Airbus A320. All 737 models have a dorsal fin at the base of the tail that forms an angle where it meets the fuselage, while the Airbus is straight.

The 737 variants that are in service today are the 3rd generation, comprised of the -700, -800, and -900 models, and the 4th generation, called Max7, Max8, Max9, and Max10 (all temporarily grounded worldwide as of 2020).  The older generations are rarely seen anymore.  Nearly all of the current 737s have winglets, either the blended shape or the scimitar shape, to improve fuel economy by reducing aerodynamic drag.

737-700 models can be identified by a single emergency exit over the wing, while all others have two.  The only significant difference between each model is length, with the -700 being the shortest.  The 737 Max has larger engines with chevron-shaped exhaust outlets.

When viewed from the front, the 737’s engines are not fully circular but slightly flattened on the bottom to help with ground clearance.

The Boeing 737 compares to the Airbus A320. All 737 models have a dorsal fin at the base of the tail that forms an angle where it meets the fuselage, while the Airbus is straight.

The 737 variants that are in service today are the 3rd generation, comprised of the -700, -800, and -900 models, and the 4th generation, called Max7, Max8, Max9, and Max10 (all temporarily grounded worldwide as of 2020).  The older generations are rarely seen anymore.  Nearly all of the current 737s have winglets, either the blended shape or the scimitar shape, to improve fuel economy by reducing aerodynamic drag.

737-700 models can be identified by a single emergency exit over the wing, while all others have two.  The only significant difference between each model is length, with the -700 being the shortest.  The 737 Max has larger engines with chevron-shaped exhaust outlets.

When viewed from the front, the 737’s engines are not fully circular but slightly flattened on the bottom to help with ground clearance.

The A320 family includes the A319, A320, and A321.  They are all the same except for length.  The A319 has one emergency exit over the wing; the A320 has two; while the longer A321 instead has an exit door in front of and behind the wing for a total of 4 exit doors per side.

The tailcone where the Auxilliary Power Unit exhaust is located on an Airbus jet extends out further and is more tapered than a Boeing 737. In addition, all A320 family aircraft have wingtip extensions called wingtip fences.

The new generation of the A320 models, called A320NEO (New Engine Option) along with A319NEO and A321NEO, can be identified by their much larger engines and sharklets replacing the wingtip fences.

The A320 family includes the A319, A320, and A321.  They are all the same except for length.  The A319 has one emergency exit over the wing; the A320 has two; while the longer A321 instead has an exit door in front of and behind the wing for a total of 4 exit doors per side.

The tailcone where the Auxilliary Power Unit exhaust is located on an Airbus jet extends out further and is more tapered than a Boeing 737. In addition, all A320 family aircraft have a wingtip extension called a wingtip fence.

The new generation of the A320 models, called A320NEO (New Engine Option) along with A319NEO and A321NEO, can be identified by their much larger engines and sharklets replacing the wingtip fences.

The A320 family includes the A319, A320, and A321.  They are all the same except for length.  The A319 has one emergency exit over the wing; the A320 has two; while the longer A321 instead has an exit door in front of and behind the wing for a total of 4 exit doors per side.

The tailcone where the Auxilliary Power Unit exhaust is located on an Airbus jet extends out further and is more tapered than a Boeing 737. In addition, all A320 family aircraft have a wingtip extensions called a wingtip fence.

The new generation of the A320 models, called A320NEO (New Engine Option) along with A319NEO and A321NEO, can be identified by their much larger engines and sharklets replacing the wingtip fences.

The Boeing 757 is in the same class as the Airbus A321 in passenger capacity. In actual measurements however, the 757 is 6 feet taller at the tail, 9 feet longer, and has a 13 foot wider wingspan. This gives the 757 a tall appearance compared to other aircraft.

There are only two versions of the 757, the 757-300 being 30 feet longer than a 757-200. All 757s will have 2 emergency exits over the wings; a 757-200 will also have 3 exit doors per side while a 757-300 will have 4 exit doors per side. Also, many airlines retrofitted their 757s with winglets to improve fuel economy similar to the 737 3rd generation above.

Boeing 757

The Boeing 757 is in the same class as the Airbus A321 in passenger capacity. In actual measurements however, the 757 is 6 feet taller at the tail, 9 feet longer, and has a 13 foot wider wingspan. This gives the 757 a tall appearance compared to other aircraft.

There are only two versions of the 757, the 757-300 being 30 feet longer than a 757-200. All 757s will have 2 emergency exits over the wings; a 757-200 will also have 3 exit doors per side while a 757-300 will have 4 exit doors per side. Also, many airlines retrofitted their 757s with winglets to improve fuel economy similar to the 737 3rd generation above.

Boeing 757

The Boeing 757 is in the same class as the Airbus A321 in passenger capacity. In actual measurements however, the 757 is 6 feet taller at the tail, 9 feet longer, and has a 13 foot wider wingspan. This gives the 757 a tall appearance compared to other aircraft.

There are only two versions of the 757, the 757-300 being 30 feet longer than a 757-200. All 757s will have 2 emergency exits over the wings; a 757-200 will also have 3 exit doors per side while a 757-300 will have 4 exit doors per side. Also, many airlines retrofitted their 757s with winglets to improve fuel economy similar to the 737 3rd generation above.

Boeing 757

The Boeing 767 and Airbus A300 (A310 is a shorter version of the A300) are widebody jets and are very similar on the outside. The main difference is the top of the fuselage under the tail slopes down on the 767 but is straight all the way out to the end of the APU on the A300. This design is common on all Airbus aircraft.

Also, on passenger versions of the A300 the windows at the rear appear to slope upward as shown.  There are few remaining A300 passenger aircraft in service.

The Boeing 767 and Airbus A300 (A310 is a shorter version of the A300) are widebody jets and are very similar on the outside. The main difference is the top of the fuselage under the tailslopes down on the 767 but is straight all the way out to the end of the APU on the A300. This design is common on all Airbus aircraft.

Also, on passenger versions of the A300 the windows at the rear appear to slope upward as shown.  There are few remaining A300 passenger aircraft in service.

The Boeing 767 and Airbus A300 (A310 is a shorter version of the A300) are widebody jets and are very similar on the outside. The main difference is the top of the fuselage under the tail slopes down on the 767 but is straight all the way out to the end of the APU on the A300. This design is common on all Airbus aircraft.

Also, on passenger versions of the A300 the windows at the rear appear to slope upward as shown.  There are few remaining A300 passenger aircraft in service.

The Boeing 787 has 3 versions: 787-8, 787-9, and 787-10.  The only difference between them is length (and seating capacity inside).  The 787-8 looks similar to a 767 and is about the same size, but the major difference is the nose which is a more aerodynamic sloping design. All 787 versions have 4 exit doors per side. Also, the wings on all 787s do not have winglets but they have a well defined upward curvature and the wingtips are more slightly curved upward as well. This improves the plane’s aerodynamics, fuel economy, and range.

The engines on this plane are very large and the rear edge of the exhaust duct has a serrated, chevron pattern (The only other Boeing jet using this engine is the new version of the 747) which helps reduce noise.

The Boeing 787 has 3 versions: 787-8, 787-9, and 787-10.  The only difference between them is length (and seating capacity inside).  The 787-8 looks similar to a 767 and is about the same size, but the major difference is the nose which is a more aerodynamic sloping design. All 787 versions have 4 exit doors per side. Also, the wings on all 787s do not have winglets but they have a well defined upward curvature and the wingtips are more slightly curved upward as well. This improves the plane’s aerodynamics, fuel economy, and range.

The engines on this plane are very large and the rear edge of the exhaust duct has a serrated, chevron pattern (The only other Boeing jet using this engine is the new version of the 747) which helps reduce noise.

The Boeing 787 has 3 versions: 787-8, 787-9, and 787-10.  The only difference between them is length (and seating capacity inside).  The 787-8 looks similar to a 767 and is about the same size, but the major difference is the nose which is a more aerodynamic sloping design. All 787 versions have 4 exit doors per side. Also, the wings on all 787s do not have winglets but they have a well defined upward curvature and the wingtips are more slightly curved upward as well. This improves the plane’s aerodynamics, fuel economy, and range.

The engines on this plane are very large and the rear edge of the exhaust duct has a serrated, chevron pattern (The only other Boeing jet using this engine is the new version of the 747) which helps reduce noise.

The A330 is a twin engine version of the 4-engine A340 model and looks very similar to the Boeing 777. As noted above, the top of the Boeing fuselage under the tail curves down while the Airbus is straight, and the window line at the rear of the A330 curves upward. The A330 has winglets while the 777 does not. The tailcone at the end of the 777 fuselage ends in a wedge shape where the APU exhaust is located while the A330 is more cone shaped.

All A330 versions have 4 exit doors per side, while the 777-200 has 4 but the longer 777-300 has an extra emergency exit over the wing.

The A330 is a twin engine version of the 4-engine A340 model and looks very similar to the Boeing 777. As noted above, the top of the Boeing fuselage under the tail curves down while the Airbus is straight, and the window line at the rear of the A330 curves upward. The A330 has winglets while the 777 does not. The tailcone at the end of the 777 fuselage ends in a wedge shape where the APU exhaust is located while the A330 is more cone shaped.

All A330 versions have 4 exit doors per side, while the 777-200 has 4 but the longer 777-300 has an extra emergency exit over the wing.

The A330 is a twin engine version of the 4-engine A340 model and looks very similar to the Boeing 777. As noted above, the top of the Boeing fuselage under the tail curves down while the Airbus is straight, and the window line at the rear of the A330 curves upward. The A330 has winglets while the 777 does not. The tailcone at the end of the 777 fuselage ends in a wedge shape where the APU exhaust is located while the A330 is more cone shaped.

All A330 versions have 4 exit doors per side, while the 777-200 has 4 but the longer 777-300 has an extra emergency exit over the wing.

The Airbus A350 comes in two versions: the A350-900 and the A350-1000, which is 23 feet longer.  These aircraft can be distinguished from other Airbus widebody jets by several features.  The window line goes straight all the way to the rear door; the cockpit is unique and features windows with rounded corners surrounded by black trim; and unique winglets that curve and sweep back.

All A350s have 4 exit doors per side, and the -900 has 4 wheels on the main landing gear while the -1000 has 6.

The Airbus A350 comes in two versions: the A350-900 and the A350-1000, which is 23 feet longer.  These aircraft can be distinguished from other Airbus widebody jets by several features.  The window line goes straight all the way to the rear door; the cockpit is unique and features windows with rounded corners surrounded by black trim; and unique winglets that curve and sweep back.

All A350s have 4 exit doors per side, and the -900 has 4 wheels on the main landing gear while the -1000 has 6.

The Airbus A350 comes in two versions: the A350-900 and the A350-1000, which is 23 feet longer.  These aircraft can be distinguished from other Airbus widebody jets by several features.  The window line goes straight all the way to the rear door; the cockpit is unique and features windows with rounded corners surrounded by black trim; and unique winglets that curve and sweep back.

All A350s have 4 exit doors per side, and the -900 has 4 wheels on the main landing gear while the -1000 has 6.