Landing Gear

 Aircraft Landing Gear

What Goes Up, Must Come Down

How Does The Landing Gear Work?

    The landing gear is one of the most important systems any aircraft has. Not only is it important for takeoff and landing, but it constantly supports the aircraft during taxi and parking as well. Typically, there are two types of gear configurations, the tricycle and tailwheel. Both consist of a main landing gear on either side of the aircraft near the center, and tricycle includes a gear in the front while tailwheel has one in the rear of the airframe. Most aircraft consist of the tricycle configuration as it allows for more forceful use of brakes, allows for better forward visibility, and provides better directional control on the ground (PHAK, 2016). 

    The brakes, nosewheel steering, and retract/extension capability are some important components of the landing gear. The brakes are obviously used in ground operation such as taxiing, but also assist in landings and steering. They're usually operated by depressing the foot pedals at the pilots feet, and by using just one foot pedal, pilots can use differential braking to assist in turns (PHAK, 2016). The nosewheel steering usually utilizes hydraulic pressure through input of a wheel or lever in the flight station to turn the aircraft on the ground. Some aircraft have the ability to retract the gear inside the airframe to allow more aerodynamic flight, and retract them again upon approach for landing.

How Important Are These Systems?

    Systems of the landing gear are imperative for safe and efficient operation of any aircraft. As mentioned in the subheading of this blog, what goes up must come down, and park too! In a non-retractable gear aircraft, if the brakes fail or the tires are not serviced/changed properly there could be major consequences upon landing or even taxiing. The same thing goes for aircraft that utilize extension/retraction and/or nosewheel steering. For example, if an aircraft takes off and there is a failure in the retraction of the gear, they could not fly as streamlined as they normally could. This would greatly effect the flight in terms of potential flight distance, altitude and speed capability, fuel usage etc. Retraction failure, however, can be catastrophic. If the gear you are supposed to land on fails to deploy correctly, the plane would be at risk of needing to make an emergency landing on it's belly or nose. 

    There are a few systems in place to prevent such catastrophe. Say, for example, a pilot realizes that his main landing gear is not deploying with the main hydraulic system. There will likely be alarms ringing and all sorts of indication immediately. Not to panic though, some aircraft have a backup hydraulic pump, or even a secondary hand-operated hydraulic pump for emergency extension of the landing gear. Back up systems in place like these can prevent accident or even tragedy.

Federal Aviation Administration (FAA). (2016). Pilot’s Handbook of Aeronautical Knowledge (PHAK). Retrieved July 13, 2022, from https://www.faa.gov/regulations_policies/handbooks_manuals/aviation/phak

(PHAK, 2016)