This again dates back to the original design of the aircraft. A 737-400 CFM56-3 engine with its unusual non-circular design due to the low fuselage. The engine housings on many of the engines used on the 737 are flat, as opposed to circular as on most other aircraft. The landing gear was not the only area of the 737 that needed alterations for a lower fuselage. But what if this failed, and the doors remained open, or they were deployed on the ground? This would be an unnecessary safety risk, so they were not added. Of course, they could be designed to close before landing, after the wheels had been extended. These require extra clearance when operated and could come into contact with the ground. Photo: Biggerben via Wikimedia No space for landing gear doorsīut with the fuselage kept lower to the ground, there was no room for landing gear doors. The 737 unpaved strip kit also helped with remote airport operation.
NO VSPD 737 LANDING SERIES
From 1969, Boeing made an optional Unpaved Strip Kit available for their 737-100 and 737-200 series aircraft. Boeing went further later with modifications to land on gravel runways in remote regions. This was a key market that Boeing wanted to capture with the 737, so the trade-offs of a lower fuselage were worth it. With a lower fuselage, smaller stairs can be used to board the 737. Keeping the aircraft lower to the ground would make it much easier to load passengers and cargo and also to service and fuel the aircraft with limited equipment. Such airports were unlikely to have air bridge facilities or baggage loading systems. This was a choice to make the 737 more usable at smaller, regional, or remote airports. The aircraft was designed to be low to the ground. This related to a design issue that dates back to the first 737-100, introduced in 1968.
Photo: Bryan via Wikimedia Keeping the aircraft low to the ground The landing gear is visible on all 737 variants. There are partial doors that cover the main landing gear struts, but not the wheels. There are no doors to cover them, but there are for the nose landing gear. Instead of being covered, though (as they are on most aircraft), they are left exposed and visible. Photo: Getty Images No landing gear doorsĪfter take-off, the 737 main landing gear wheels are raised into a cavity within the main fuselage. The landing gear wheels remain visible in flight. This has been the case since the first 737 was introduced, and it is because of the limited space under the aircraft when on the ground. On most other aircraft, it is covered by closing doors. If you look at the underside of the Boeing 737 shortly after takeoff or in flight, you will see that the main landing gear wheels sit exposed after folding into their housing.