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 @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-pilot’s seat • 1 in cabin area • Each charged to 125 psi.

8. AST 473CE-550 Citation II Systems Pneumatics

9. 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).

15. 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, copilot’s 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.