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Airplane Flying Handbook
Transition to Jet Powered Airplanes
JET ENGINE IGNITION

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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

Jet engine power controls.
Figure 15-3. Jet engine power controls.

The temperature of turbine gases must be closely
monitored by the pilot. As in any gas turbine engine,
exceeding temperature limits, even for a very few
seconds, may result in serious heat damage to turbine
blades and other components. Depending on the make
and model, gas temperatures can be measured at a
number of different locations within the engine. The
associated engine gauges therefore have different
names according to their location. For instance:
• Exhaust Gas Temperature (EGT)—the temperature
of the exhaust gases as they enter the tail
pipe, after passing through the turbine.
• Turbine Inlet Temperature (TIT)—the temperature
of the gases from the combustion section of
the engine as they enter the first stage of the turbine.
TIT is the highest temperature inside a gas
turbine engine and is one of the limiting factors
of the amount of power the engine can produce.
TIT, however, is difficult to measure. EGT
therefore, which relates to TIT, is normally the
parameter measured.
• Interstage Turbine Temperature (ITT)—the
temperature of the gases between the high
pressure and low pressure turbine wheels.
• Turbine Outlet Temperature (TOT)—like EGT,
turbine outlet temperature is taken aft of the
turbine wheel(s).

JET ENGINE IGNITION

Most jet engine ignition systems consist of two igniter
plugs, which are used during the ground or air starting
of the engine. Once the start is completed, this ignition
either automatically goes off or is turned off, and from
this point on, the combustion in the engine is a
continuous process.

CONTINUOUS IGNITION

An engine is sensitive to the flow characteristics of the
air that enters the intake of the engine nacelle. So long
as the flow of air is substantially normal, the engine
will continue to run smoothly. However, particularly
with rear mounted engines that are sometimes in a
position to be affected by disturbed airflow from the
wings, there are some abnormal flight situations that
could cause a compressor stall or flameout of the
engine. These abnormal flight conditions would usually
be associated with abrupt pitch changes such as
might be encountered in severe turbulence or a stall.
In order to avoid the possibility of engine flameout
from the above conditions, or from other conditions
that might cause ingestion problems such as heavy
rain, ice, or possible bird strike, most jet engines are
equipped with a continuous ignition system. This system
can be turned on and used continuously whenever
the need arises. In many jets, as an added precaution,
this system is normally used during takeoffs and landings.
Many jets are also equipped with an automatic
ignition system that operates both igniters whenever
the airplane stall warning or stick shaker is activated.

FUEL HEATERS

Because of the high altitudes and extremely cold outside
air temperatures in which the jet flies, it is possible
to supercool the jet fuel to the point that the small

Figure 15-4. Jet engine r.p.m. gauges.
Figure 15-4. Jet engine r.p.m. gauges.

 

15-3