AST 473 CE 550 Citation II Systems

1
AST 473CE 550 Citation II Systems

• Fire Protection System

2
General

• 2 separate but identical engine fire detection
  extinguishing systems
• Components
• Sensing loops (turbine scn. And acc. Scn.)
• Control units
• ENG Fire warning switchlight (ea. Engine)
• Extinguisher bottles (2 ea.)
• Fire detection circuit test function

3
General Ctn.

• Fire Bottles
• -Located in tail cone (check on preflight)
• -Charged to 600 psi _at_70 degrees (use scale)
• -Monobromotriflouromethane, CBrF (3)- not
  corrosive- no residue
• -Discharged by Squibb (explosive cartridge)
• -Both bottles available to either engine (30s)
• -Filler fuse melts at 210 deg. F discharge

4
Operation

• 1 cable each engine- monitored by a control unit
  (tail cone) measuring electrical resistance which
  decreases with temp.
• At 500 deg. F. the circuit completes causing the
  red Eng Fire light to illuminate but not tripping
  the MWL.
• Powered by main DC power

5
Operation

• At L or Rt. Eng. Fire light
• Verify fire- temp gauges
• Push Respective Eng. Fire light (lift cover)
• Illuminates both bottle armed lights arming
  them
• Closes fuel and hydraulic firewall shutoff valves
  (fuel press/hyd. Press low lights illuminate)
• Generator field relay tripped (gen. off light
  illuminates).
• Thrust reverser isolation valve circuit disabled

6
Operation Ctn.

• Pressing bottle armed switch light discharges the
  bottle contents into selected engine
• A second bottle can be fired in 30 sec. if
  needed.
• Depressing ENG FIRE switchlight again
• Opens firewall shutoff valves
• Disarms extinguishing system
• Reverser isolation valve re-enabled
• (gen. field will be reset upon eng. Start)

7
Portable Extinguishers

• 2ea. 2.5 lb. Halon extinguishers in interior
• 1 under co-pilots seat
• 1 in cabin area
• Each charged to 125 psi.

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AST 473CE-550 Citation II Systems

• Pneumatics

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General

• Engine Compressor Bleed Air provides pressurized
  air to a pneumatic manifold for distribution to
• Left and Rt. Flow control valves for use by the
  Air Cycle Machine (ACM- AiResearch)
• Ground Valve- ACM ground ops.
• Emergency Valve- alt. pressurization source
• Service Air System Valves (windshield anti-ice,
  cabin door seal, deice boots, Instr. Air)

10
General

• 1 engine can supply total system needs
• Airflow control into cabin controlled by the
  PRESS SOURCE selector (6 pos.) just to the right
  of the pedestal.
• Temp. sensors in the system illuminate
  annunciators on the main panel (Air Duct
  Overheat, L/R Precool fail)

11
Operation

• Engine Bleed Air flows to the welded cluster
  assembly (manifold) to
• Pneumatic valves to Windshield Anti-ice
• Vacuum ejector
• Pneumatic Distribution Regulator (for boots,
  instrument air, and door seal)
• Air from left eng. Cluster flows to the
  emerg.valve for emerg. Pressurization (direct
  bleed air to cabin only in flight- cabin temp.
  controlled by throttle position)

12
Operation

• Air from the Right engine is routed through the
  right pneumatic cluster to the ground valve for
  use by the ACM during ground ops.- 18 lbs/min.
• Flow from both clusters is routed through both
  main pneumatic flow control shutoff valves for
  use by the ACM (normal ops.)

13
Operation

• Prior to this, bleed air flows through an
  air-to-air heat exchanger flow control valve
  (automatic valve) which directs air through or
  around a Precooler which lowers the temp. to 500
  deg. F. prior to entering tailcone
• If airflow out of the precooler exceeds 540 deg.
  F. the PRECOOL FAIL light illuminates.

14
Control

• Press Source selector determines
• Amount of air entering cabin
• Source of that air
• It is a 7 position switch (OFF, GND, LH, NORMAL,
  BOTH HI, RH, EMER).

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OFF

• Closes all environmental bleed-air valves
• LH and RH flow control valves energized closed by
  DC
• EMER valve is energized closed
• NO air enters pressure vessel from engines (if
  depressurized ram air from tailcone flows into
  cabin)
• Bleed Air still available to service Air system
  (door seal, copilots ADI, vacuum ejector pump,
  and deicer boots)

16
Ground

• For ground use only
• Allows up to 18 ppm air from RT. Engine into
  pneumatic manifold
• Illuminates BLD AIR GND annunciator
• Need 60 N2 for full 18ppm flow

17
LH/RH Position

• Limit pneumatic bleed air input to ACM and
  Service Air systems
• LH position isolates the flow from the rt. Eng.
  And visa-versa- only one valve can be closed at
  any one time
• IE. If LH is selected (due to a RH pre-cool
  failure) and the Left eng. Fails all air to the
  ACM is lost unless RH is re-selected

18
Normal

• De-energizes open the left and right flow control
  and shutoff valves and allows air from both
  engines to pass into the manifold T/O perf.
  Based on this position

19
Both HI

• Position Energizes left and right flow control
  valves to a higher position to allow 9ppm air
  into the ACM
• Needed for low power settings
• Illuminates BLEED AIR GND/HI light
• Prohibited for T/O and lndgs. And high pwr.
  Settings
• If main DC lost, valves fail to the 6ppm normal
  low flow mode

20
EMER

• Direct Bleed air to cabin
• In this position (or whenever the valve opens
  automatically the EMER PRESS ON annunciator
  illuminates and all other valves energize closed

21
DC power fail

• System defaults to the NORMAL setting
• Ground and Emerg. Press. Valves fail closed
• Two flow control and shutoff valves fail open to
  low flow mode
• Pneumatic Distribution valves fail open.