Pneumatic Air Conditioning System Citation, Citation I

Pneumatic Air Conditioning System Citation, Citation I COCKPIT VENT FOOT WARMER OVERHEAD COCKPIT WINDSHIELD WEMAC OPTIMAL VENT OVERHEAD CONDITIONED AIR DUCTS BLOWER SIDE WINDOW UNDER FLOOR CONDITIONED AIR DUCT HI LOW 20A O F F RH PAX FOOTWARMER CABIN FAN CABIN HI LOW OUTLETS OUTLETS OUTLET CABIN TEMPSENSORS & BLOWER ASSEMBLY O F F LH PAX FOOTWARMER RAM AIR COLD AIR BLEED AIR LH MAIN DC BUS MIXING TUBE HEAT EXCHANGER COOLERED BLEED AIR CONDITIONED AIR CHECK BAGGAGE COMPARTMENT WARMER SMOKE DETECTOR MOTOR 100 F (38 C) THERMOSWITCH RIGHT FLOW CONTROL AND SHUTOFF (6 LBS / MIN) OUTFLOW S AFT PRESSURE BULKHEAD CABIN FAN 1 1 2 DUCT TEMP SENSOR EMERGENCY PRESSURIZATION, (18 LB/MIN) GROUND CONTROL PRESSURE REGULATING, (18 LB/MIN) BLEED AIR CLUSTER AMBIENT AIR IN WATER SEPARATOR RELIEF (45 PSI) FAN BYPASS MIXING BLEED AIR CLUSTER LEFT FLOW CONTROL AND SHUTOFF (6 LB/MIN) T C LH MAIN DC EXT BUS NORM PRESS LH GND WATER TO ASPIRATOR AT AMBIENT AIR INLET 5A NORM OFF AMBIENT AIR OUT RH EMER PNEUMATIC ACTUATOR ACM TURBINE (T) AND COMPRESSOR (C) ACM OVERHEAT SENSOR (450 F / 232 C) RH CROSSOVER BUS EMER PRESS RAM AIR HEAT EXCHANGERS OVERBOARD PLENUM 5A EMER PRESS ON 3 Environmental Systems 5A MANUAL HOT MANUAL COLD 1 TEMP 2 AIR DUCT O'HEAT ENGINE BLEED AIR CONE ANTI-ICE FUEL SYSTEM INLET ANTI-ICE OIL SEALS STATOR ANTI-ICE STATOR COOLING T1 PROBE ANTI-ICE TURBINE COOLING SYSTEM BLEED AIR CABIN PRESS CONTROL COPILOT'S HORIZON DOOR SEAL W/S BLEED AIR DEICE BOOTS TEMPERATURE CONTROL OFF COLD MANUAL DUCT OVERHEAT SENSOR (275 F, 300 F, 315 F) AUTOMATIC HOT 3 Environmental Systems Citation I/II/SII May 1998 For training only 4C-1

4C-2 For training only Citation I/II/SII

Environmental Systems Pneumatic Air Conditioning System Citation II 002 to 484 FOOTWARMER MANIFOLD LH MAIN EXT BUS OVHD HI LOW 20A O F F CABIN FAN HI LOW CPT LH MAIN EXT BUS AIR FLOW DISTR CABIN 5A NORM PRESS LH GND NORM 5A EMER PRESS BOTH HI RH OFF EMER PRESS SOURCE RH CROSSOVER BUS (540 ±6 F) R PRECOOL FAIL BLEED AIR GND HI 1 5A TEMP RH FLOW CONTROL (NO) RIGHT BLEED AIR CLUSTER TEMPERATURE CONTROL MANUAL AUTOMATIC SELECTOR COLD HOT COLD HOT COCKPIT VENT FOOTWARMER ARMREST MANIFOLD AFT PRESSURE BULKHEAD SOLENOID TO TCS REGULATOR (AUTO TEMP CONTROL) WINDSHIELD WEMAC CABIN TEMP. SENSOR & BLOWER ASSY. (LOC. ABOVE INTERIOR HEADLINER) OUTLETS (WEMAC) CABIN AIR OVERHEAD DUCT CHECK BLOWER MAIN PLENUM AUXILIARY PLENUM SMOKE DETECTOR OVERHEAD BLOWER MIXING TUBE 315 F 2 SYSTEMS BLEED AIR 35 TO 39 F 30 TO 285 F (LH) FLOW CONTROL (NO) GROUND SHUTOFF & REG WATER SEPARATOR TO W/S BLEED AIR HEAT EXCHANGER RELIEF 36 TO 40 PSI T C RAM AIR IN ACM TURBINE (T) COMPRESSOR (C) ACM O'HEAT SENSOR 450 F OPTIONAL VENT SIDE WINDOW PASSENGER FOOTWARMER 1 RESTRICTOR ARMREST WARMER ENGINE BLEED AIR OIL SEALS TURBINE COOLING CONE ANTI-ICE T 1PROBE ANTI-ICE STATOR ANTI-ICE STATOR COOLING FUEL SYSTEM INLET ANTI-ICE PRECOOLER UNDER FLOOR DUCT 2 FLOW DIVIDER SYSTEM BLEED AIR COPILOT'S HORIZON DOOR SEAL CABIN PRESS CONTROL MANUAL TEMP CONTROL W/S BLEED AIR DEICE BOOTS OUTFLOW S THERMOSWITCH 100 F/38 C EMER PRESS (N/C) AIR DUCT O'HEAT EMERG PRESS ON ACM EJECTOR ON (315 F) SOLENOID 1 PRE-COOLER (BYPASS AIR) BYPASS MIXING JET PUMP SHUTOFF L PRECOOL FAIL RAM AIR OUT LEFT BLEED AIR CLUSTER (540 ±6 F) JET PUMP RAM AIR COLD AIR BLEED AIR HEAT EXCHANGER COOLED BLEED AIR CONDITIONED AIR Citation I/II/SII May 1998 For training only 4C-3

4C-4 For training only Citation I/II/SII

Environmental Systems Pneumatic Air Conditioning System Citation II 484, 485 and sub; SII 1 2 SYSTEMS BLEED AIR ENGINE BLEED AIR CONE ANTI-ICE T1 PROBE ANTI-ICE INLET ANTI-ICE STATOR ANTI-ICE STATOR COOLING TURBINE COOLING OIL SEALS FUEL SYSTEM COCKPIT VENT FOOT WARMER DE-ICE BOOTS W/S BLEED AIR PRESS CONTROLLER DOOR SEAL WING ANTI-ICE 23 PSI CONTROLLER FOOT WARMER MANIFOLD ARMREST MANIFOLD LH MAIN BUS EXT OVHD HI LOW 20A O F F CABIN AIR HI LOW CPT AIR FLOW DISTR CABIN RH MAIN DC BUS (AFT J BOX) 20A FLOOD COOLING ON OFF FLOOD COOLING AFT PRESSURE BULKHEAD RIGHT FLOW CONTROL SHUTOFF (6 LBS / MIN) FLOOD COOLING FLOOD COOLING FRESH AIR RIGHT BLEED AIR CLUSTER RT WING ANTI-ICE GROUND CONTROL (18 LBS/MIN) 1 PRIMARY OVERPRESSURE SWITCH NORM PRESS 5A LH MAIN BUS EXT LH GND TEMP 5A NORM OFF RH EMER ACM O'PRESS BLEED AIR GND RH CROSSOVER BUS 5A EMER PRESS AUXILIARY PLENUM OVERHEAD BLOWER SECONDARY OVERPRESSURE SWITCH RAM AIR 3 WINDSHIELD SIDE WINDOW Citation I/II/SII May 1998 WEMAC COCKPIT VENT FOOT WARMER WEMAC CABIN TEMP SENSOR & BLOWER ASSEMBLY (ABOVE INTERIOR HEADLINER) PASSENGER FOOTWARMER RAM AIR COLD AIR BLEED AIR HEAT-EXCHANGER COOLED BLEED AIR CONDITIONED AIR For training only RESTRICTOR OUTLETS (WEMAC) ARMREST WARMER MANUAL HOT MANUAL COLD OVERHEAD DUCT UNDER-FLOOR DUCT CHECK TEMPERATURE CONTROL OFF COLD MANUAL BLOWER MAIN PLENUM AUTOMATIC HOT 3 MIXING TUBE FLOW DIVIDER OUTFLOW S 100 F (38 C) THERMOSWITCH LT WING ANTI-ICE LEFT BLEED AIR CLUSTER DUCT O'HEAT SENSOR EMERGENCY PRESSURIZATION 2 SYSTEMS BLEED AIR 1 AMBIENT AIR IN FAN WATER SEPARATOR WATER TO ASPIRATOR AT AMBIENT AIR INLET LEFT FLOW CONTROL SHUTOFF (6 LBS / MIN) T C BYPASS MIXING COOLING TURBINE (T) AND COOLING COMPRESSOR (C) AMBIENT AIR OUT BLEED AIR PRECOOLER ACM OVERHEAT SENSOR 450 F OVERBOARD PLENUM HEAT EXCHANGER EMERG PRESS ON AIR DUCT O'HEAT 315 F (157 C) 4C-5

4C-6 For training only Citation I/II/SII

Environmental Systems Pressurization System Citation 001 to 214 INSTRUMENT AIR SYSTEM VACUUM CABIN PRESSURE CONTROLLER RATE DEC INC 1 2 3 4 5 6 CABIN PRESSURE CONTROL 0 AIRPLANE ALT AT MAX DIFF -1 10 1000 18 19 FEE CABIN ALT SETTING 7 9 8 CABIN ALT STATIC PORT EMERGENCY DUMP CABIN ALTITUDE LIMIT TEST (SAFETIED) AFT PRESSURE BULKHEAD NORMAL OUTFLOW TEST (SAFETIED) FILTER STATIC PORT CABIN ALTITUDE LIMIT SQUAT SWITCH OPERATED SOLENOID FILTER SAFETY OUTFLOW CONTROL AIR STATIC AIR CABIN AIR VACUUM Citation I/II/SII May 1998 For training only 4C-7

4C-8 For training only Citation I/II/SII

Environmental Systems Pressurization System Citation 214 and sub; CI; CII; CII-627; SII 28V DC LH/RH DC BUSES PNEUMATIC RELAY ASSEMBLY CONTROL CABIN ALTITUDE LIMIT (13,000 FT ±1,500) MANUAL SHUTOFF NO. 2 PORT "1" SOLENOID AIR "A" (NORMALLY OPEN) RELAY REG. VACUUM BREATHER PLUG 28V DC AIRCRAFT ELECTRICAL SYSTEM SOLENOID AIR "B" (NORMALLY CLOSED) TEST PORT NO. 1 TEST PORT NO. 2 TEST PORT NO. 3 RESTRICTED TEE FITTING CABIN ALTITUDE LIMIT (13,000 FT ±1,500) CABIN AIR PRESSURE OUTFLOW CONTROL CHAMBER AUXILIARY VOLUME TANK SOLENOID AIR "C" (NORMALLY CLOSED) RESTRICTED TEE FITTING RESTRICTED ELBOW FITTING ASSEMBLY PORT "2" EMER DUMP (NORMALLY CLOSED) 4-WAY RESTRICTED FITTING ASSEMBLY RESTRICTED TEE FITTING CONTROL CHAMBER PORT "2" AIRCRAFT TAILCONE CABIN ALTITUDE SELECTOR KNOB OUTFLOW CONTROLLER ACF CABIN 8 7 6 FACE VIEW 5 X CABIN CONTROLLER ALT CABIN RATE CONTROL SELECTOR KNOB FORWARD RH LH <80% >85% <80% >85% THROTTLE SWITCHES LANDING GEAR SWITCH FLT GRND CABIN ATMOSPHERE AIR FILTER ASSEMBLY SYSTEMS SERVICE BLEED AIR VACUUM OUTFLOW CONTROL REFERENCE PRESSURE DISCHARGE PRESSURE CABIN PRESSURE REGULATED VACUUM CONTROL CABIN AIR PRESSURE OUTFLOW PORT "1" MANUAL SHUTOFF NO. 3 CHECK MANUAL SHUTOFF NO. 1 IN-LINE FILTER TEST PORT BLEED AIR VACUUM JET PUMP AND REGULATOR (3.75 TO 4.75 HG) Citation I/II/SII May 1998 For training only 4C-9

4C-10 For training only Citation I/II/SII

Environmental Systems Bleed Air Sources Bleed air from each engine s centrifical compressor flows through transfer tubes and elbow assemblies before entering the bleed air cluster. At the bleed air cluster, the bleed air flow splits to supply the: air conditioning and pressurization systems through the left and right flow control shutoff valves emergency pressurization through emergency pressurization valve (left engine only) ground air conditioning through ground shutoff valve or shutoff pressure regulating valve (right engine only). airframe anti-icing and deicing system (see Ice and Rain Protection). On Citation II units 002 to 484 except 482, hot bleed air from each engine flows through a precooler before flowing to the bleed air cluster. If bleed air temperature exceeds 540 F (282 C), the appropriate PRECOOL FAIL annunciator illuminates. Bleed air from the right engine also supplies the automatic temperature control system regulator. Citation I/II/SII For training only 4C-11

The PRESS SOURCE selector controls bleed air flow from the engines to the bleed air cluster through the flow control shutoff, ground shutoff, and emergency pressurization valves (see Table 4C-1). Position OFF GND LH NORM BOTH HI RH EMER Function Left and right flow control shutoff valves closed. Left and right flow control shutoff valves closed. Ground shutoff valve or shutoff pressure regulating valve (Citation II units 002 to 484 except 482) opens when right engine is operating. Left flow control shutoff valve opened and right flow control shutoff valve closed. Left engine supplies bleed air for air conditioning system. Left and right flow control shutoff valves open with engines supplying bleed air for air conditioning system. Normal operating position. Left and right flow control shutoff valves open at high flow rate (Citation II units 002 to 484 except 482). Right flow control shutoff valve open and left flow control shutoff valve closed. Right engine supplies bleed air for air conditioning system. Emergency pressurization valve open and left and right flow control shutoff valves closed. All bleed air routed into cabin for emergency pressurization. Table 4C-1; PRESS SOURCE Switch Selection 4C-12 For training only Citation I/II/SII

Air Conditioning Environmental Systems On the ground with the PRESS SOURCE selector in the GND position, the left and right flow control shutoff valves close and the ground shutoff valve or shutoff pressure regulating valve (Citation II units 002 to 484 except 482) opens. Bleed air from the right engine flows through the open ground shutoff valve to the air conditioning system. On Citation II and SII aircraft, with the ground shutoff or shutoff pressure regulating valve open, the BLEED AIR GND HI or BLEED AIR GND annunciator illuminates. With both engines operating and the PRESS SOURCE selector in the NORM position, the left and right flow control shutoff valves open. Engine bleed air then flows from each engine to the air conditioning system. A bypass valve, controlled by the temperature control system, opens to bypass hot bleed air from the air cycle machine (ACM). As the bypass valve opens, more air bypasses the ACM resulting in hotter air entering the cabin and cockpit. On Citation, Citation I, and Citation II units 002 to 484 except 482, the bypass valve opens to bypass the primary heat exchanger. On Citation II units 482; 485 and subsequent and Citation SII aircraft, the bypass valve opens to bypass the ACM compressor. Hot bleed air flowing through the primary heat exchanger partially cools before flowing to the compressor. As the rapidly spinning compressor squeezes the bleed air it heats. If the temperature of bleed air leaving the compressor reaches 435 to 450 F (224 to 232 C), a temperature sensor initiates an air conditioning system shutdown by closing the left and right flow control shutoff valves and opening the emergency pressurization valve. If temperature drops within 12 seconds, the system resets. The emergency pressurization valve closes and the flow control valves open. After 12 seconds, the system must be manually reset by the crew. Citation I/II/SII For training only 4C-13

The warmer pressurized bleed air then flows to the secondary heat exchanger for the next stage of cooling. Air then flows to the ACM turbine where it rapidly expands and cools as it expends energy to turn the turbine. The turbine, in turn, drives the compressor. On Citation, Citation I, and Citation II units 485 and subsequent, and Citation SII, the turbine also drives a fan that draws ram air through the heat exchangers. Cold moisture-laden air leaving the ACM turbine passes through the centrifugal water separator before it combines with hot bleed air bypassed from the air conditioning system. As the air enters the water separator, a swirling motion induced by vanes separates water from the air. The extracted water is drawn across the ACM heat exchangers to aid cooling. Finally, the temperature controlled air enters the pressure vessel through a check valve in the aft pressure bulkhead. From this point the air flow splits to supply the overhead and underfloor air conditioning ducts. Temperature Control With the TEMPERATURE CONTROL knob in the AUTOMATIC range, the temperature controller responds to temperature data provided by a temperature sensor in the air conditioning duct and the overhead cabin. The controller then commands the bypass valve to open or close to increase or decrease the temperature of air entering the distribution ducts. On Citation, Citation I, Citation II units 482, 485 and subsequent, and Citation SII, placing the TEMPERATURE CONTROL knob in the MANUAL position allows the crew to manually control cabin temperature by directly opening or closing the bypass valve with the MANUAL HOT/MANUAL COLD switch. Holding the switch in the MANUAL HOT position opens the bypass valve to increase cabin temperature; holding it in the MANUAL COLD position closes the bypass valve to decrease cabin temperature. When released, the switch spring-loads to the OFF position with the bypass valve remaining at its last position. 4C-14 For training only Citation I/II/SII

Environmental Systems On Citation II units 002 to 484 except 482, placing the TEM- PERATURE CONTROL SELECTOR in the manual position (toward MANUAL knob) allows the crew to manually control cabin temperature with the MANUAL knob. Rotating the knob counterclockwise closes the bypass valve to decrease air temperature. Rotating the knob clockwise opens the bypass valve to increase cabin temperature. On Citation II and SII, adjusting the AIR FLOW DISTR knob between the CKPT and CABIN positions operates a motor-driven flow divider that controls air flow into the cabin armrest and foot warmer manifolds and the underfloor cockpit supply duct. Placing the CABIN or OVHD switch in HI or LOW activates a blower that increases airflow through the overhead ducts. Flood Cooling (Optional) On Citation II units 482 and 485 and subsequent; SII, placing the FLOOD COOLING switch in the ON position energizes a blower fan and closes the normal air conditioning supply duct. Most of the conditioned air from the air conditioning system then flows through a grill in the aft pressure bulkhead. This system allows for rapid cooling of the cabin on the ground and in flight below 10,000 ft. Ram Air Supply A ram air scoop in the vertical stabilizer fin through a check valve supplies fresh air to the air conditioning system and the cabin. The check valve prevents cabin pressurization loss through the ram air ventilation system. Citation I/II/SII For training only 4C-15

Pressurization With the air conditioning system operating, a constant supply of pressurized air enters the cabin. The pressurization system then maintains a selected cabin climb rate, altitude, and descent rate by governing cabin pressure loss through pneumatically operated outflow valves. On the Citation units 001 to 213, the system has a normal outflow valve and a safety outflow valve directly controlled by the pressurization controller. On Citation units 001 to 213 with SB 21-9, Citation I, Citation II, and SII aircraft, the system has two outflow valves indirectly controlled by the pressurization controller through a pneumatic relay. Safety devices built into system prevent complete loss of cabin pressurization or an excessive cabin pressure differential rate. Depending on the aircraft, the system s 8.0 to 8.7 PSID maximum cabin pressure differential provides a comfortable cabin altitude up to the aircraft s maximum operating altitude (see Table 4C-2). Aircraft Maximum Maximum Operating Cabin PSID Altitude Citation 001 to 213 35,000 8.0 ±0.1 Citation 001 to 213 with SB 21-9, Citation 213 and 41,000 8.5 ±0.1 subsequent; Citation I Citation II and SII 43,000 8.7 ±0.1 Table 4C-2; Cabin Pressurization 4C-16 For training only Citation I/II/SII

Environmental Systems Normal Operation On Citation units 001 to 213, the instrument air vacuum source supplies control pressure for the pressurization system. On Citation units 214 and subsequent, Citation I, II, and SII aircraft, with an engine operating, bleed air directed through a pressure regulator and ejector supplies vacuum for operation of the pressurization system. After setting the desired cabin climb rate and cruising altitude on the pressurization controller, the system begins pressurizing the cabin once the aircraft takes off. On the Citation units 001 to 213, a single squat switch controls system pressurization and depressurization as the aircraft takes off and lands. On all other aircraft, two 85% N 2 RPM switches and a squat switch control system pressurization and depressurization. As the aircraft climbs to altitude, the pressurization controller responds to an imbalance created within its control chambers by commanding the outflow valves to close. As the outflow valves close, less cabin air escapes the cabin. When the aircraft reaches cruising altitude, the system maintains the selected cabin altitude by maintaining the necessary cabin pressure differential between cabin pressure and ambient pressure. If the pressurization system fails to control the outflow valves and cabin altitude increases to 13,000 ±1,500 ft, cabin altitude limit valves overcome opening pressure to close the outflow valves. If cabin differential pressure exceeds the normal operating value, the outflow valves open partially to release excess pressure to atmosphere. During landing, actuation of the squat switch commands the outflow valves to open and equalize cabin pressure with ambient pressure. Citation I/II/SII For training only 4C-17

Emergency Dump Lifting the guard then moving the EMER DUMP lever up supplies vacuum to both outflow valves to open them and depressurize the cabin. With the PRESS SOURCE switch in any other position than OFF, the cabin altitude limit valves prevent cabin altitude from exceeding 13,000 ±1,500 ft. Emergency Pressurization If cabin altitude climbs to 10,000 ±350 ft, the CABIN ALT annunciator illuminates and the Master Warning lights flash. If cabin altitude continues climbing, placing the PRESS SOURCE selector in the EMER position closes the left and right flow control shutoff valves, opens the emergency pressurization valve, and illuminates the EMERG PRESS ON annunciator. Hot bleed air obtained directly from the left engine flows into the distribution ducts to pressurize the cabin. 4C-18 For training only Citation I/II/SII

Environmental Systems Environmental Systems Bleed Air System Power Source Distribution Control Monitor Protection HP bleed air from either/both engine(s) Air cycle machine (ACM) Automatic temperature control selector (CII 001 to 484) Copilot s horizon gyro (except CII-627 and subsequent) Door seal Engine anti-ice system Fuel system Left engine to cabin (EMER position) Pressurization controller Windshield bleed air Wing deice system (C0/CI/CII) Bleed air cluster valves Bleed air pressure regulator ENGINE ANTI ICE switches Lower forward door latch pin PRESS SOURCE selector SURFACE DEICE switch/ejectors W/S BLEED HI/LOW switch W/S BLEED AIR manual shutoff valves Gyro pressure gage Vacuum pressure gage (C0 001 to 213) Annunciators BLD AIR GND EMERG PRESS ON ENG ANTI FAIL LH/RH L/R PRECOOL FAIL (CII 002 to 481, 483, and 484) SURFACE DEICE W/S AIR O HEAT Circuit breakers Fail safe valves Sensors Citation I/II/SII For training only 4C-19

Environmental Systems (cont.) Air Conditioning System Power Source Distribution Control Monitor Protection Air cycle machine (ACM) Ram air Mixing valve (bypass modulating and shutoff valve) Overhead duct Underfloor duct PRESS SOURCE selector Auto temp rheostat Manual temp rheostat (CII 002 to 481, 483, and 484) Switches fan OVHD fan Cabin fan (C0; CI) FLOW DISTR selector (CII; SII) TEMPERATURE CONTROL SELECTOR (C0; CI; CII 482, 485 and subsequent; SII) CABIN TEMP indicator (optional) Annunciators AIR DUCT O HEAT EMERG PRESS ON BLEED AIR GROUND (C0; CI 001 to 469) BLD AIR GND/HI (CI 470 and subsequent; CII; SII) ACM EJECTOR ON (CII 002 to 481, 483, and 484) ACM O PRESS (CII 482, 485 and subsequent; SII) Circuit breakers 4C-20 For training only Citation I/II/SII

Environmental Systems Pressurization System Power Source Distribution Control Monitor Protection Emergency pressurization from left engine HP bleed air from either/both engine(s) Emergency pressurization duct Overhead ducts Under-floor ducts Aircraft pressurization controller CABIN RATE knob Control power (28V DC and vacuum) Landing gear squat switch (left) Outflow valves PRESS SOURCE rotary selector Pressure regulator Throttles Annunciators ACM O PRESS CABIN ALT 10,000 FT BLD AIR GND (C0, CI 001 TO 469) BLD AIR GND/HI (C1 470 and subsequent; CII; SII) EMERG PRESS ON CABIN ALT/DIFF PRESS indicator Cabin altitude limit switches Circuit breakers Emergency dump valve Oxygen system Passenger oxygen system baro-sensor 10,000 ft cabin sensor Citation I/II/SII For training only 4C-21

4C-22 For training only Citation I/II/SII