Q14-12. What types of brakes are used on aircraft
Regulated hydraulic pressure is applied through
where more braking friction is desired with
the automatic adjuster to a chamber in the bearing
lower pressures?
carrier. The bearing carrier is bolted to the shock strut
axle flange and serves as a housing for the annular
Q14-13. What is the total number of pucks installed on
actuating piston. Hydraulic pressure forces the
dual disc brakes?
annular piston to move outward, compressing the
Q14-14. What traps a predetermined amount of fluid in
rotating discs, which are keyed to the landing wheel,
the brake to give correct clearance between
and the stationary discs, which are keyed to the bearing
the rotating discs and the stationary discs in
carrier. The resulting friction causes a braking action
multiple/trimetallic brake systems?
on the wheel and tire assembly.
Q14-15. What types of brakes are designed for
When the hydraulic pressure is relieved, the
high-pressure hydraulic systems and are
retracting springs force the actuating piston to retract
considered heavy-duty brakes?
into the housing chamber in the bearing carrier. The
hydraulic fluid in the chamber is forced out by the
BRAKE SYSTEM MAINTENANCE
return of the annular actuating piston, and is bled
through the automatic adjuster to the return line. The
LEARNING OBJECTIVE: Identify the two
automatic adjuster traps a predetermined amount of
primary brake systems. Identify the checks required to
fluid in the brake--an amount just sufficient to give
make sure these systems operate properly.
correct clearances between the rotating discs and
Brake systems are designed to retard or to stop
stationary discs. See figure 14-12
aircraft motion on the ground. They also aid in
The trimetallic disc type brakes are used on most
controlling the direction of the aircraft while it is
naval aircraft. They operate on the same basic
taxiing. Provisions exist for applying either one or
both brakes and for varying the braking action by the
principle as the multiple disc brakes.
amount of movement or force exerted on the brake
SEGMENTED ROTOR BRAKES
pedal.
Several types of naval aircraft have an antiskid
Segmented rotor brakes are heavy-duty brakes,
system integrated with the wheel brake system to allow
especially adapted for use with high-pressure
maximum braking. This results in a short landing roll
hydraulic systems. These brakes may be used with
and skid-free control as the aircraft comes to a stop.
either power brake control valves or power boost
A large portion of the maintenance effort expended
master cylinders. Braking is accomplished by means
by an AM in an operating activity is directed toward
of several sets of stationary, high-friction type of brake
troubleshooting and repairing of brakes and brake
linings making contact with rotating (rotor) segments.
systems. A brake system is generally one of two major
A cutaway view of the brake is shown in figure 14-13.
types--independent or power. Independent systems
As you can see, the segmented rotor brake is very
operate independently of a pressure source other than
similar to the multiple disc type, described in the
the master cylinder. Power brake systems use utility or
previous section.
main hydraulic system pressure from the aircraft. The
power brake systems allow for higher brake line
The brake assembly consists of a carrier, two
pressures than can be obtained with the independent
pistons and piston cup seals, a pressure plate, an
system.
auxiliary stator plate, rotor segments, stator plates, a
compensating shim, automatic adjusters, and a
INDEPENDENT-TYPE BRAKE SYSTEM
backing plate.
The depth of independent brake system
Q14-9. What types of disc brakes are usually installed
maintenance allowable at the intermediate and
on medium-sized aircraft?
organizational levels of maintenance varies with the
Q14-10. On disc brake assemblies, brake linings are
complexity of the components. System maintenance at
often referred to by what name?
the organizational level generally consists of servicing,
Q14-11. When are operational checks on disc brakes
troubleshooting, parts replacement, and "on aircraft"
usually performed?
repairs.
14-11
