Airplane Flying Handbook
Preface
Table of Contents
Chapter 1,Introduction to Flight Training
Chapter 2,Ground Operations
Chapter 3,Basic Flight Maneuvers
Chapter 4, Slow Flight, Stalls, and Spins
Chapter 5, Takeoff and Departure Climbs
Chapter 6,
Ground Reference Maneuvers
Chapter 7, Airport Traffic Patterns
Chapter 8, Approaches and Landings
Chapter 9,
Performance Maneuvers
Chapter 10, Night Operations
Chapter 11,Transition to Complex Airplanes
Chapter 12,
Transition to Multiengine Airplanes
Chapter 13,Transition to Tailwheel Airplanes
Chapter 14,
Transition to Turbo-propeller Powered Airplanes
Chapter 15,Transition to Jet Powered Airplanes
Chapter 16,Emergency Procedures
Glossary
Index |
These switches de-energize the hydraulic pump after
the landing gear has completed its gear cycle. In the
event of limit switch failure, a backup pressure relief
valve activates to relieve excess system pressure.
switches. Each gear has two limit switches—one
dedicated to extension and one dedicated to retraction.
These switches de-energize the hydraulic pump after
the landing gear has completed its gear cycle. In the
event of limit switch failure, a backup pressure relief
valve activates to relieve excess system pressure.
CONTROLS AND POSITION INDICATORS
Landing gear position is controlled by a switch in the
cockpit. In most airplanes, the gear switch is shaped
like a wheel in order to facilitate positive identification
and to differentiate it from other cockpit controls.
[Figure 11-6]
Landing gear position indicators vary with different
make and model airplanes. The most common types of
landing gear position indicators utilize a group of
lights. One type consists of a group of three green
lights, which illuminate when the landing gear is down
and locked. [Figure 11-6] Another type consists of one
green light to indicate when the landing gear is down
and an amber light to indicate when the gear is up. Still
other systems incorporate a red or amber light to
indicate when the gear is in transit or unsafe for
landing. [Figure 11-7] The lights are usually of the
"press to test" type, and the bulbs are interchangeable.
[Figure 11-6]
Other types of landing gear position indicators consist
of tab-type indicators with markings "UP" to indicate
the gear is up and locked, a display of red and white
diagonal stripes to show when the gear is unlocked, or
a silhouette of each gear to indicate when it locks in
the DOWN position.
LANDING GEAR SAFETY DEVICES
Most airplanes with a retractable landing gear have a
Figure 11-6. Typical landing gear switches and position indicators.
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gear warning horn that will sound when the airplane is
configured for landing and the landing gear is not
down and locked. Normally, the horn is linked to the
throttle or flap position, and/or the airspeed indicator
so that when the airplane is below a certain airspeed,
configuration, or power setting with the gear retracted,
the warning horn will sound.
Accidental retraction of a landing gear may be
prevented by such devices as mechanical down locks,
safety switches, and ground locks. Mechanical
down locks are built-in components of a gear retraction
system and are operated automatically by the gear
retraction system. To prevent accidental operation of
the down locks, and inadvertent landing gear retraction
while the airplane is on the ground, electrically
operated safety switches are installed.
A landing gear safety switch, sometimes referred to as
a squat switch, is usually mounted in a bracket on one
of the main gear shock struts. [Figure 11-8] When the
strut is compressed by the weight of the airplane, the
switch opens the electrical circuit to the motor or
mechanism that powers retraction. In this way, if the
landing gear switch in the cockpit is placed in the
RETRACT position when weight is on the gear, the
gear will remain extended, and the warning horn may
sound as an alert to the unsafe condition. Once the
weight is off the gear, however, such as on takeoff, the
safety switch will release and the gear will retract.
Many airplanes are equipped with additional safety
devices to prevent collapse of the gear when the
airplane is on the ground. These devices are called
ground locks. One common type is a pin installed in
aligned holes drilled in two or more units of the
landing gear support structure. Another type is a
spring-loaded clip designed to fit around and hold two
or more units of the support structure together. All
types of ground locks usually have red streamers
permanently attached to them to readily indicate
whether or not they are installed.
Figure 11-7. Typical landing gear switches and position indicators.
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