Presentation on theme: "AST 473 CE 550 Citation II Systems"— Presentation transcript:
1 AST 473 CE 550 Citation II Systems Fire Protection System
2 General2 separate but identical engine fire detection & extinguishing systemsComponents:Sensing loops (turbine scn. And acc. Scn.)Control unitsENG 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 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 Operation1 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 themCloses 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 engineA second bottle can be fired in 30 sec. if needed.Depressing ENG FIRE switchlight again:Opens firewall shutoff valvesDisarms extinguishing systemReverser 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 seat1 in cabin areaEach charged to 125 psi.
9 GeneralEngine 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 sourceService 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 OperationEngine Bleed Air flows to the welded cluster assembly (manifold) to:Pneumatic valves to Windshield Anti-iceVacuum ejectorPneumatic 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 OperationAir 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 OperationPrior 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 tailconeIf 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 airIt 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 DCEMER valve is energized closedNO 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 manifoldIlluminates BLD AIR GND annunciatorNeed 60% N2 for full 18ppm flow
17 LH/RH PositionLimit pneumatic bleed air input to ACM and Service Air systemsLH position isolates the flow from the rt. Eng. And visa-versa- only one valve can be closed at any one timeIE. 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 NormalDe-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 HIPosition Energizes left and right flow control valves to a higher position to allow 9ppm air into the ACMNeeded for low power settingsIlluminates BLEED AIR GND/HI lightProhibited for T/O and lndgs. And high pwr. SettingsIf 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 closedTwo flow control and shutoff valves fail open to “low flow” modePneumatic Distribution valves fail open.
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