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Pilot's Handbook of Aeronautical Knowledge
Aircraft Systems
Superchargers and Turbosuperchargers

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Pilot's Handbook of Aeronautical Knowledge



Table of Contents

Chapter 1, Introduction To Flying
Chapter 2, Aircraft Structure
Chapter 3, Principles of Flight
Chapter 4, Aerodynamics of Flight
Chapter 5, Flight Controls
Chapter 6, Aircraft Systems
Chapter 7, Flight Instruments
Chapter 8, Flight Manuals and Other Documents
Chapter 9, Weight and Balance
Chapter 10, Aircraft Performance
Chapter 11, Weather Theory
Chapter 12, Aviation Weather Services
Chapter 13, Airport Operation
Chapter 14, Airspace
Chapter 15, Navigation
Chapter 16, Aeromedical Factors
Chapter 17, Aeronautical Decision Making




Fuel injection system.
Figure 6-13. Fuel injection system.

A fuel injection system is considered to be less susceptible to
icing than the carburetor system, but impact icing on the air
intake is a possibility in either system. Impact icing occurs
when ice forms on the exterior of the aircraft, and blocks
openings such as the air intake for the injection system.

Advantages of fuel injection:
• Reduction in evaporative icing
• Better fuel flow
• Faster throttle response
• Precise control of mixture
• Better fuel distribution
• Easier cold weather starts

• Difficulty in starting a hot engine
• Vapor locks during ground operations on hot days
• Problems associated with restarting an engine that
quits because of fuel starvation

Superchargers and Turbosuperchargers

To increase an engine's horsepower, manufacturers have
developed forced induction systems called supercharger
and turbosupercharger systems. They both compress the
intake air to increase its density. The key difference lies in
the power supply. A supercharger relies on an engine-driven
air pump or compressor, while a turbocharger gets its power
from the exhaust stream that runs through a turbine, which in
turn spins the compressor. Aircraft with these systems have
a manifold pressure gauge, which displays MAP within the
engine's intake manifold.

On a standard day at sea level with the engine shut down,
the manifold pressure gauge will indicate the ambient
absolute air pressure of 29.92 "Hg. Because atmospheric
pressure decreases approximately 1 "Hg per 1,000 feet of
altitude increase, the manifold pressure gauge will indicate
approximately 24.92 "Hg at an airport that is 5,000 feet above
sea level with standard day conditions.

As a normally aspirated aircraft climbs, it eventually reaches
an altitude where the MAP is insufficient for a normal climb.
That altitude limit is the aircraft's service ceiling, and it is
directly affected by the engine's ability to produce power.
If the induction air entering the engine is pressurized, or
boosted, by either a supercharger or a turbosupercharger,
the aircraft's service ceiling can be increased. With these
systems, an aircraft can fly at higher altitudes with the
advantage of higher true airspeeds and the increased ability
to circumnavigate adverse weather.