Undercarriage arrangements

Source: Wikipedia, the free encyclopedia.

Below are featured the wheeled undercarriage (also called landing gear) arrangements of some modern commercial jet airliners and large military aircraft.

Types of wheeled units

This table shows the main types of individual, basic wheeled units (single-wheel unit or bogies composed of multiple wheels) used on most aircraft undercarriages.

Symbol Wheeled unit Example
2 wheels, 1 axle
Airbus A380 nose landing gear (consisting of a single 2-wheel bogie)
4 wheels, 2 axles
An Airbus A330's main landing gear (consisting of two 4-wheel bogies)
6 wheels, 3 axles
A Boeing 777's main landing gear (consisting of two 6-wheel bogies)
14 wheels, 7 axles
Antonov An-225
's main landing gear (consisting of two 14-wheel bogies)

The tables below show how various types of wheeled units are arranged to form the undercarriages of some popular aircraft from manufacturers Antonov, Airbus, and Boeing.

Antonov

Aircraft Wheels and
Configuration
Nose section Center section Example
An-225
32 wheels
[2x2]+[2x14]
Antonov An-225
with its 32-wheel landing gear. Note the front gear made of two independent, parallel 2-wheel bogies

Airbus

Aircraft Wheels and
Configuration
Nose section Center section Example
A318, A319, A320, A321 (standard) 6 wheels
[1x2]+[2x2]
bmi
A300, A310, A320, A330, A350-900 10 wheels
[1x2]+[2x4]
Airbus A350-900 of Vietnam Airlines
A340-200/300 12 wheels
[1x2]+[2x4+1x2]
Airbus A340-300 from Kuwait Airways. Note the usage of an isolated 2-wheel unit in the central landing gear (similar to the MD-11
)
A340-500/600 14 wheels
[1x2]+[3x4]
Airbus A340-600 of Virgin Atlantic
A350-1000 14 wheels
[1x2]+[2x6]
Airbus A350-1000 of Qatar Airways
A380 22 wheels
[1x2]+[2x4+2x6]
Airbus A380 in Airbus markings

Boeing

Aircraft Wheels and
Configuration
Nose section Center section Example
717, 727, 737 6 wheels
[1x2]+[2x2]
A Boeing 737 from Southwest Airlines
747 18 wheels
[1x2]+[4x4]
A Boeing 747-400's main landing gear. Note the toes-up bias angle of the bogies on the wing gear, to ensure correct stowage upon retraction
707, 720, 757, 767, 787 10 wheels
[1x2]+[2x4]
Boeing 757-200 from British Airways
777 14 wheels
[1x2]+[2x6]
Boeing 777-200 from United Airlines. Using 6-wheel bogies, instead of the common 4-wheel bogies (reminiscent of earlier generation Tupolev Tu-154
), was visionary for contemporary aircraft at the time of the design of the 777
B-52 Stratofortress
8 main wheels plus 2 outrigger wheels
[2x2]+[2x2]
A Boeing B-52 Stratofortress featuring its characteristic landing gear with 8 wheels under fuselage and two outrigger wheels near wingtips