One of the more curious quirks of the Boeing 737—a mainstay in commercial aviation—is that it doesn’t have landing gear doors covering its main wheels when retracted. While it may seem like an oversight compared to modern aircraft designs, this is actually an intentional and longstanding design choice.
When the main landing gear of a 737 retracts after takeoff, the wheels fold into partially enclosed wheel wells, but remain exposed underneath the wing roots. In contrast, many newer aircraft have full landing gear doors that close after the wheels retract, creating a smooth aerodynamic surface.
So, why did Boeing leave the gear exposed?
1. Simplicity and Weight Reduction
The original 737 was designed in the 1960s with a focus on simplicity, ease of maintenance, and cost-efficiency. Omitting complex gear door mechanisms helped reduce the number of moving parts, which translates to lower maintenance requirements and less potential for mechanical failure. It also saves weight—every pound counts when it comes to fuel efficiency and performance.
2. Low Ground Clearance
The 737 was initially intended to serve smaller regional airports that lacked sophisticated ground equipment. To facilitate easy loading and maintenance, the aircraft was designed with a low ground clearance. This design limited the available space for the landing gear to fully retract and be covered by doors without significant structural changes.
3. Durability and Reliability
Landing gear doors can be vulnerable to foreign object damage (FOD)—especially on rough or debris-prone runways. By keeping the gear partially exposed, Boeing reduced the chances of damage to fragile door mechanisms, improving operational durability, especially for airlines operating in a wide range of environments.
4. It Works Just Fine
Despite the open wheel wells, the exposed landing gear doesn’t significantly affect the aircraft’s aerodynamics or fuel efficiency—at least not enough to outweigh the benefits of a simpler design. Boeing has retained this design across all variants of the 737, including the latest 737 MAX series, demonstrating that the advantages continue to outweigh the drawbacks.
In essence, the Boeing 737’s lack of full landing gear doors is a purposeful trade-off—a product of its era that remains effective to this day. It’s a reminder that sometimes, simpler really is better in aviation design.
