1. PNEUMATIC SYSTEMS

2.  The learning objective of this
presentation, To develop the student's
knowledge of the vacuum system to meet
the basic functions in vacuum system that
supply essential instruments of the aircraft
and ability to detect abnormal or unsafe
operation and responding to a vacuum
system failure

3. •Aircraft Pneumatic System Intro
•Vacuum Systems
•Pneumatic Use in Small Aircraft
•Pneumatic System Components
•Air Pumps
•Pneumatic System Operation
•Actions before every flight
•Failure Causes
•Early Recognition
•Emergency Procedures
•Spatial Disorientation
•Redundancy Options

4.  Sometimes called vacuum pressure systems
 Aircraft Pneumatic Systems power
Instruments, *landing gear, *flaps, air
conditioning, windows, doors and more
 In light Aircraft, Suction Pressure Gauge
shows Vacuum System Pressure

5. •Pumps
•Relief Valves
•Vacuum Air Filter
•Suction Gauge Gyro
instruments:
-Attitude Indicator
-Heading Indicator

6. • Gyro compass
• Artificial Horizon
• Turn coordinator

7. •Air Pump
•Vacuum Regulator
•Inlet Air Filter
•Overboard Vent Line
•Gauges:
– Attitude Indicator
– Heading Indicator
•System Indicators
– Suction Gauge – Gyro
Flag
– Annunciator Lights

8. • Pneumatic Air Filter
- Prevent system
contamination
- Remove air particulates
- Clean air is essential to
good operation

9. • Pneumatic Pressure
Regulator
- Prevents System
over pressurization
- Insures proper
calibration

10. Heart of pneumatic system is pressure or vacuum air pump
(Usually engine driven)
• Two basic types :
•Wet air pumps use engine oil to lubricate pump internally
•Dry air pumps - more common –have graphite vanes inside pump
casing - self-lubricate as pump rotates

11. •Filtered Air is pulled through
system by vacuum pump
•Evacuated air passes through
instrument case causes gyro
to spin
•Spinning gyros provide
“rigidity in space” for
instrument references
•Air exhausts through Gyro
Pressure Gauge exhaust port
– Gauge measures system
pressure
•Failure Warning Systems

12. Check for oil leaks
Check the hose
And clamps for
Oil leaks
Check for
loose fittings Check for
that allow external
contaminants damage
into the
system

13. • System Contamination
-Solid particles in pneumatic
system damage pump
and plug valve openings
–Liquids from oil, water, or engine
cleaning solvents
• Restriction/ leaks within the system
-A loose fitting or damaged hoses
-Worn out, misused, or incorrectly
routed hoses
• Sudden changes in engine speed
- Abrupt engine deceleration
- Sudden engine stoppage

14. • Pneumatic System health can be
determined by the indications on
either the vacuum gauge or flags on
the attitude indicator

15.  Inaccurate/conflicting Instrument
information
 Suction/pressure gauge indicates outside
normal operating (green) range
 Spotting pneumatic system failure early
reduces chances of spatial disorientation

16. 95% are Fatal 1995-2004 Accidents
cause by vacuum Failure
5% non Fatal
1st Qtr
2nd Qtr
 While pneumatic system failures alone
do not cause accidents, spatial
disorientation does, and tragically
these accidents are almost always
fatal

18. • Activate a back up power supply for
pneumatics ( aux Vacuum pump if have)
• Maintain partial panel instrument flying
- Cover up or simulate loss of flight instruments
• Make timed turns
• Notify ATC
• In IMC –seek and fly VMC

19. When your instruments disagree ,confusion
,dizziness, and uncertainly can cause loss of
control. Spatial disorientation occurs quickly when
outside visual reference
is poor such as night, IMC , Haze

20.  Electrical Power Instruments
 Secondary Air pump ( Electric Aux Vacuum
Pump)
 Pressure differential Switch

21.  Pneumatic Systems fail at unexpected times
 The danger , in the event of pneumatic system
failure is spatial disorientation
 Have a good knowledge what power systems
on the aircraft you fly
 Practice on the partial panel Flying and be
familiar with aircraft instruments
 Whether you rent , own ,or operate become
familiar with the maintenance history of the
Aircraft

22. -Aircraft Pneumatic System Intro
-Vacuum Systems
-Pneumatic Use in Small Aircraft
-Pneumatic System Components
-Air filter
-Regulator
-Air Pumps
-Pneumatic System Operation
-Actions before every flight
-Failure Causes
-Early Recognition
-Statistics
-Emergency Procedures
-Spatial Disorientation
-Redundancy Options
-Conclusion