CHAPTER 12
LANDING GEAR, BRAKES, AND
HYDRAULIC UTILITY SYSTEMS
Chapter Objective: Upon completion of this chapter, you will have a working
knowledge of the maintenance required for the aircraft landing gear and brakes.
You will have a working knowledge of the hydraulic utility systems, such as nose
gear steering, catapult, arresting gear, skid control systems, and other related
systems.
Maintenance on the landing gear and brakes, at
times, requires maintenance of related systems. In this
chapter, we will discuss the general landing gear
systems and brake systems first, and then we will
discuss various hydraulic utility systems. We will also
examine drop checking procedures, troubleshooting,
and the alignment and adjustment of the landing gear.
The systems discussed in the following paragraphs
are representative. For training purposes, we will use
many values for tolerances and pressures to illustrate
normal operating conditions. When actually performing
the maintenance procedures discussed, you must consult
the current applicable technical publications for the
exact values to be used.
LANDING GEAR SYSTEMS
Learning Objective: Identify the various types
of landing gear systems used on fixed-wing and
rotary-wing aircraft.
Every aircraft maintained in today’s Navy is
equipped with a landing gear system. Most Navy aircraft
also use arresting and catapult gear. The landing gear is
that portion of the aircraft that supports the weight of the
aircraft while it is on the ground. The landing gear
contains components that are necessary for taking off
and landing the aircraft safely. Some of these com-
ponents are landing gear struts that absorb landing and
taxiing shocks; brakes that are used to stop and, in some
cases, steer the aircraft; nosewheel steering for steering
the aircraft; and in some cases, nose catapult com-
ponents that provide the aircraft with carrier deck
takeoff capabilities.
FIXED-WING AIRCRAFT
Landing gear systems in fixed-wing aircraft are
similar in design. Most aircraft are equipped with the
tricycle-type retractable landing gear. Some types of
landing gear are actuated in different sequences and
directions, but practically all are hydraulically operated
and electrically controlled. With a knowledge of basic
hydraulics and familiarity with the operation of
actuating system components, you should be able to
understand the operational and troubleshooting
procedures for landing gear systems.
Main Landing Gear
The typical aircraft landing gear assembly consists
of two main landing gears and one steerable nose
landing gear. As you can see in figure 12-1, a main gear
Figure 12-1.–Tricycle landing gear.
12-1
