CHAPTER 5
JET AIRCRAFT ENGINE
LUBRICATION SYSTEMS
CHAPTER OBJECTIVES
After completing this chapter, you will be able to:
Identify the types, characteristics, and require-
Identify maintenance procedures of oil
ments of lubricants in aircraft engines; and
systems and system parts, including oil pres-
recognize sources and procedures for the pre-
sure adjustments; oil filter removal, inspec-
vention of oil contamination.
tion, and installation; and metal particle
identification.
Recognize the two main types and major parts
of lubrication systems.
Recognize the goals and requirements of the
Navy Oil Analysis Program (NOAP) to in-
clude proper oil sampling techniques, required
NOAP forms and recommended action, and
required logbook entries for NOAP.
The increased complexity of aircraft engines
operating conditions. Maintenance instruction
manuals (MIMs) or maintenance requirements
has added to the requirements for proper lubrica-
tion. Jet engines require lubrication to prevent
cards (MRCs) list the type of lubricant required
friction from reducing the engines' efficiency. Oil
for specific aircraft maintenance tasks. With an
is the lifeblood of the aircraft engine. If the oil
understanding of the different types of lubricates,
their characteristics, and purposes, you will know
supply to the bearings stops, the lubricating films
why we must use the proper lubricant. Using the
break down and cause scoring, seizing, and
wrong type of lubricant, mixing different types,
burning between moving parts. Fortunately, the
o r improper lubrication can cause extra
engine oil pump and oil system are dependable.
maintenance man-hours, part failures, and
Like the heart and circulatory system of the
accidents.
human body, they quietly perform their function
so well we forget their importance.
TYPES OF LUBRICANTS
Lubricants are classified according to their
LUBRICANTS
source--animal, vegetable, petroleum, mineral,
or synthetic. Animal oils are not suitable
The primary purpose of any lubricant is to
lubricants for internal-combustion engines. They
reduce friction caused by metal-to-metal contact.
form fatty acids, which cause corrosion when
Lubricating oils provide a film that permits
exposed to high temperatures. Vegetable oils have
surfaces to glide over one another with less
good lubricating qualities, but break down (they
friction. Therefore, lubrication is essential to
change in chemical structure) after long periods
prevent wear in mechanical devices where surfaces
of operation in internal-combustion engines.
rub together.
Mineral-base lubricants are usually divided into
The Navy uses many different types of
three groups--solids, semisolids, and liquids.
lubricants. The selection of the proper lubricant
Petroleum-based oils (for example, MIL-L-6081
depends on the design of the equipment and the
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