PSA Airlines CRJ Overhead Panel and Aircraft Systems Exhaustive Study Guide

Electrical Power System

  • DC SERVICE Switchlight

    • Connects the DC Service Bus to the APU Battery Direct Bus.

  • BATTERY MASTER Switch

    • Connects the APU Battery Direct Bus and the Main Battery Direct Bus to the Battery Bus.

  • AC ESS XFER Switchlight

    • ALTN (White) Light: Indicates that the Essential Bus (ESS BUS) is being powered by AC Bus 2.

    • Transfer Logic: Transfer is automatic when AC Bus 1 fails.

  • AC POWER (External Power)

    • AVAIL: Indicates external power is connected and ready for use.

    • IN USE: Indicates the external AC power unit is currently supplying the electrical system.

  • IDG 1 & IDG 2 DISC (Integrated Drive Generator Disconnect)

    • Used to disconnect the IDG from the Engine Accessory Gearbox.

    • FAULT: Indicates a fault within the IDG, specifically High Oil Temperature or Low Oil Pressure (HOT LOP).

    • Automatic Disconnect: The IDG will automatically disconnect when an Overtemperature or Overtorque condition occurs.

    • Mechanical Logic: Pressing DISC energizes an electrical solenoid, causing the drive gear to retract from the engine accessory gearbox.

  • Generator 1, 2, & APU Switches

    • OFF/Reset: Disconnects the generator from its associated bus and/or resets the generator control circuit.

  • AUTO XFER Switchlight

    • Used to disable the automatic transfer of the associated IDG.

    • FAIL: Indicates a fault is preventing autotransfer.

    • Generator Trip Conditions: Generators trip off due to Over/Under Voltage, Over/Under Frequency, Gen/Bus over-current, or Generator out of phase.

  • Engine Accessory Gearbox Components

    • FADEC Alternator

    • Engine Oil Pump

    • ATS (Air Turbine Starter)

    • Engine Fuel Pump

    • Engine driven Hydraulic Pump

    • Integrated Drive Generators (IDGs)

  • Five Verified Actions (Critical Procedures)

    1. Guarded Switches

    2. Throttle switches

    3. Gen Switches

    4. Fire Push Switches

    5. Fuel Pumps

Fire Protection and Detection (FIDEEX)

  • System Testing

    • Press to TEST: Tests engine and APU detection systems, cargo bay smoke detectors, and the extinguishing system.

    • FIDEEX Monitoring: Monitors the electrical resistance of loops. When both loops experience the same decrease in resistance, a "FIRE/OVHT" message is sent to the EICAS.

    • Pre-start Check: Ensure the "APU FIRE FAIL" message is not on the EICAS before starting the APU.

  • Engine Fire Push Selection Effects

    • Closes the Fuel SOV (Shutoff Valve).

    • Closes the Bleed Air SOV.

    • Closes the Hydraulic SOV.

    • Trips the engine-driven generator off.

  • APU Fire Push Selection Effects

    • APU shuts down.

    • APU Fuel Pump shuts off.

    • APU LCV (Load Control Valve) closes.

    • Squibs are armed.

  • Detection Areas and Mechanics

    • Engines: Dual-loop detection. Two bottles located in the Aft Equipment Bay. Each bottle has 2 firing squibs. Both bottles can be discharged into one engine.

    • APU: Dual-loop detection.

      • On Ground: APU shuts down automatically; bottle discharges automatically after 5 seconds5\,seconds.

      • In-Flight: APU shuts down automatically, but the crew must manually discharge the bottle.

    • MLG (Main Landing Gear): Single-loop detection. Constantly monitors temperatures in the wheel bins.

    • Cargo Bay:

      • 3 smoke detectors in the FWD compartment.

      • 2 smoke detectors in the AFT compartment.

      • 2 FIREX bottles in the right wing fairing (each bottle has 2 squibs).

      • Discharge logic: One bottle discharges immediately; the second bottle discharges over time.

    • Fire Extinguishing Agent: Halon bottles pressurized to 600 PSI600\,PSI.

Hydraulic System

  • Hydraulic SOV (Shutoff Valve)

    • Electrically-operated valve that interrupts fluid flow from the reservoir to the EDP (Engine Driven Pump).

    • Purpose: Used in the event of a hydraulic leak or overtemperature to close the valve without needing to shut down the engines.

  • ACMP (AC Motor Pump) Distribution

    • Pump 1B & 3A: Powered by AC BUS 2.

    • Pump 3B & 2B: Powered by AC BUS 1.

  • Pump Logic (Auto Mode)

    • For "B" pumps to activate: Associated Bus must be powered, Flaps must be at a position other than 00, and at least one Generator must be operating.

  • System Cooling

    • Systems 1 and 2 are cooled by a single oil heat exchanger. Cooling air is directed from the ram air scoop across the heat exchanger.

  • ADG (Air Driven Generator) Interaction

    • ADG automatically powers ACMP 3B to maintain hydraulic pressure for primary flight controls regardless of switch position.

    • The ADG also powers: ADG Bus, AC ESS Bus, Slats/Flaps at half speed, and Stab Trim.

Fuel System

  • Boost Pumps

    • DC electric pumps move fuel from collector tanks to engines.

    • Used to back up Main Ejectors during engine start or when ejectors fail.

    • INOP: Indicates low pump pressure or pump failure when armed.

  • Fuel Crossflow (XFLOW)

    • Gravity XFLOW: Open signifies the Gravity XFLOW SOV is open; FAIL signifies it is not in the commanded position.

    • Powered XFLOW: Starts automatically with a fuel imbalance of 200 lbs200\,lbs and stops when the low tank reaches +50 lbs+50\,lbs over the other side.

    • Manual XFLOW: Selected via XFLOW AUTO OVERRIDE.

    • Imbalance Caution: Appears if the imbalance between wing tanks exceeds 800 lbs800\,lbs.

  • Fuel Check Valve Test

    • With one engine running, boost pumps are turned off to prove fuel will not flow from the left ejector to the right engine (or vice versa). EICAS should show "PUMP/PUMP/PRESS."

Bleed Air and Anti-Ice

  • Wing Anti-Ice (A/I) Cross Bleed

    • FROM LEFT: Right wing Anti-Ice valve is closed; wing cross-bleed valve is open.

    • FROM RIGHT: Left wing Anti-Ice valve is closed; wing cross-bleed valve is open.

    • Fail Position: Valves are spring-loaded to the CLOSED position.

  • Bleed Air Sources

    • Engine stages provided: 6th6^{th} and 10th10^{th}.

    • Bleed Valves: Switch to APU to open LCV and close engine bleeds; switch to Manual to arm ISOL and bleed source.

  • Ice Protection Logic

    • Cowl Anti-Ice: Fail-safe to the OPEN position. Requires air pressure from the manifold and electrical power to close.

    • Wing Anti-Ice: "ON" activates the AILC (Anti-Ice Leak Detection System) to modulate/shut off valves and maintain the leading edge temperature range. Higher temperatures are required for Slats (Piccolo Tube).

    • Probes and Sensors: Automatically heated in "Flight Mode" (Weight Off Wheels/WOW) or during takeoff regardless of switch position. There are 3 Air Data sensor heater controllers.

Auxiliary Power Unit (APU)

  • Operating Limitations

    • Max In-Flight Starting Altitude: 37,000 FT37,000\,FT.

    • Max Operating Altitude: 41,000 FT41,000\,FT (40 KVA40\,KVA limit).

    • APU Door Limitation: If door position is open or unknown, airspeed is restricted to 220 kts220\,kts or the APU must remain in operation.

    • Starter Limitation: Limited to 3 start attempts in 1 hour1\,hour, with a 2 minute2\,minute delay between attempts.

    • Battery Requirement: Main and APU batteries must be at a minimum of 22 Volts22\,Volts.

  • APU Start Sequence (Ground)

    1. APU SOV Open.

    2. APU IN BITE (Built-In Test Equipment).

    3. APU RPM gauges displayed.

    4. APU Door Open.

    5. At 99% RPM+2 seconds99\%\,RPM + 2\,seconds, the Green AVAIL light illuminates.

Ignition System

  • System Logic

    • IGNITION A: Powered by the AC Essential Bus.

    • IGNITION B: Powered by the Battery Bus through a static inverter.

    • Continuous Ignition: When pressed, activates both A and B systems on both engines.

  • Continuous Ignition Limitations (Required Usage)

    • Takeoff and landing on contaminated runways.

    • Takeoff with high crosswind components (15 kt15\,kt or greater).

    • Flight through moderate or heavier intensity rain.

    • Flight through moderate or heavier intensity turbulence.

    • Flight in the vicinity of thunderstorms.

Pressurization System

  • Emergency Depressurization (EMER DEPRESS)

    • Restricts cabin altitude to a maximum of 14,500±500 FT14,500 \pm 500\,FT.

    • If the aircraft is below 14,500 FT14,500\,FT, it will fully depressurize.

  • Controller Logic

    • CPCP (Cabin Pressure Control Panel): Controls cabin altitude to not exceed 15,000 FT15,000\,FT.

    • CPAM (Cabin Pressure Acquisition Module):

      • ≥8,500 FT\geq 8,500\,FT: CABIN ALT Caution message.

      • ≥10,000 FT\geq 10,000\,FT: CABIN ALT Warning message; NO SMOKING/FASTEN SEAT BELT signs illuminate.

      • 14,000 FT14,000\,FT: Passenger oxygen masks drop.

    • CPAM Failure: CPCP generates EICAS messages, but seat belt signs and mask drops will NOT occur automatically.

  • Abort Modes

    • Takeoff Abort Mode: Thrust levers retarded to IDLE; cabin depressurizes at 500 fpm500\,fpm for 20 seconds20\,seconds, then the outflow valve opens fully.

    • Flight Abort Mode: Activates if the aircraft does not exceed 6,000 FT6,000\,FT in 10 minutes10\,minutes and initiates a 1000 fpm1000\,fpm descent. Elevation resets to departure field elevation.

  • Pressure Limitations

    • Max Cabin Pressure: +8.7 PSI+8.7\,PSI.

Air Conditioning (Packs)

  • Pack Operation

    • Max Single Pack Altitude: 31,000 FT31,000\,FT.

    • Components: Air Cycle Machine, Dual Heat Exchanger, Re-Heater, and Condenser.

    • RAM AIR: Allows air from the scoop to enter the conditioned duct (RAM AIR SOV Open).

    • RECIRC FAN: Mixes recirculated air with conditioned air for the flight deck and cabin.

  • Cargo Bay Conditioning (AFT)

    • AIR: SOVs open; recirculated air ventilates the bay.

    • COND AIR (Puppy Killer): SOVs open; recirculated and conditioned air ventilate the bay. An electric heater maintains temperature between 60∘F60^\circ F and 80∘F80^\circ F.