Event: CPT 3

Last updated: 7 April, 2003 1:31
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  1. Caution System (see CAUTION PANEL)
  2. Hydraulic System
    Reduces pilot workloads by reducing control pressures and feedback generated by the main rotor system. Primary parts are the power pack, filter, pressure switch, solenoid valve, and servos.
    1. Power pack - Fwd side of xmssn and driven by the xmssn accessory gearbox. Has a reservoir area that holds one pint of fluid. Gravity fed to pump which pressurizes up to 600 +/- 50 psi. Cooled by finned radiator and engine oil cooler blower air, and regulated by pressure valve.
    2. Filter - Removes foreign matter, and has NO bypass system. Has red indicator that pops if clogged.
    3. Pressure Switch - Monitors hydraulic fluid pressure. Lights Hydraulic Pressure if pressure falls below 300 and extinguishes if above 400 psi.
    4. Solenoid Valve - Valve spring-loaded to the OPEN position and requires electricity to bypass system. With the Hydraulic switch ON, there is NO power and the hydraulic fluid flows to servos. In the OFF position, electricity activates the solenoid and fluid does not enter the servos. Valve is designed to be fail/safe, so in case of electric failure hydraulic boost is still active. {It is important to understand exactly how this valve works for the Hydraulic EP's. Pulling the C/B should allow fluid to flow and system to work. Turning OFF switch uses power, and deactivates system}
    5. Servo Actuators - Converts pilot control movements to blade movements through hydraulic fluid pressure. Uses a pilot valve which is mechanically connected to flight controls to adjust the amount of fluid entering the servo to move the actuators which move the blade through linkages. [NATOPS 2.10, Systems Ch. 6]
  3. PAN/Mayday reports:
    Pilot's priorities are to Aviate, Navigate, Communicate.
    Mayday - Indicates imminent and grave danger and that assistance is required
    Pan - Indicates uncertainty or alert, followed by the nature of the urgency [FTI 6-5]
    Use ISPI format (Identification, Situation, Position, Intentions)
  4. Autorotation into the trees
    LANDING IN THE TREES [NATOPS 15.1.1] An autorotation into a heavily wooded area should be accomplished by executing a normal autorotation and full flare. The flare should be executed so as to reach a zero rate of descent and zero groundspeed as close to the top of the trees as possible. As the helicopter settles, increase collective to maximum. If time permits during autorotation:

    1. Autorotate
    2. Shoulder harness - Lock
    If time and altitude permit:
    3. Crew/passengers - Alert
    4. Mayday - TRANSMIT on Guard
    5. Transponder - Emergency
    6. Twist grip - Close
    7. Generator - OFF
    8. Battery - OFF


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(none for this event)


  1. Generator / electrical malfunctions

      Indications: Load meter zero, GEN FAIL caution light illumination,
      (B) DC voltmeter indicates battery voltage, © Voltmeter indicates 0

      • With the battery switch OFF or battery exhaustion, both fuel boost pumps are in operative. Descend below 6,000 ft pressure altitude and land as soon as possible.
      • With one or both boost pumps inoperative, fuel quantity below 20 gallons shall be considered unusable.

      • Prior to shutting off all electrical power, the pilot must determine the equipment that is essential to the particular light environment that will be encountered (e.g. flight instruments and boost pumps).
      • In the TH-57C, time of operation of ESS No. 2 bus on battery power is approximately 40 minutes with pitot OFF and an 80% charged battery (approximately 35 minutes with pitot heat ON). To conserve battery power as needed for extended flights or for use of landing lights at destination, turn BAT switch OFF during flight.
      • With the NORMAL/RECOVER switch on NORMAL, failure of the main generator will result in illumination of the FUEL PUMP caution light because of loss of power to nonessential bus.
      • Resetting the bus/tie relay circuit breaker will cause the main battery to power the nonessential us, accelerating main battery depletion.

      1. GEN FIELD and GEN RESET circuit breaker - Check in
      2. MAIN GEN switch Reset, then ON
        If generator power is not restored:
      3. MAIN GEN switch Off
      4. Unnecessary electrical equipment Off
        © 5. NORMAL/Recover switch - Recover as Desired
      6. Descend below 6,000 ft
      7. Land as soon as possible
         If power is restored:
      8. Continue flight

      • In the TH-57C, with the loss of the main battery after a main generator failure, the HIS and both RMIs will be inoperative for TACAN, LOC and VOR approaches. However, the RMIs will still provide relative ADF bearing. VMC should e attained as soon as possible.
      • Be prepared for a possible electrical and / or engine compartment fire because of excessive wiring load or generator meltdown.

      Indications: Loadmeter or voltmeter fluctuates erratically, pegs or goes to zero

      1. Generator - Cycle
      If the problem is corrected:
      2. Continue flight.
      If the problem is not corrected:
      3. Use generator failure procedure.

      • Sustained loadmeter indications greater than 70 percent may be caused by an electrical fire.

  2. Hydraulic system malfunctions
    Note: Odd or unusual stick forces will be felt in a boost-off situation. Because of excessive forces required for control manipulation, a shallow approach with a sliding landing is recommended.
      Indications: HYDRAULIC PRESSURE LIGHT, Increased force required for control movement, Feedback in control

      1. Airspeed Adjust (to obtain most comfortable control movement level)
      2. HYDRAULIC BOOST switch - Check ON
      3. HYD BOOST circuit breaker - Out
         If system is restored:
      4. Land as soon as practicable
          If system is not restored:
      5. HYD BOOST circuit breaker - In
      6. HYDRAULIC BOOST switch Off
         © 7. FORCE TRIM (FT) On
         © 8. AFCS STAB On
         © 9. AFCS ALT Off
      10. Land as soon as practicable
      Indications: Cyclic / collective control displaces to abnormal position, Pilot control of cyclic / collective is difficult or impossible.

      • Hydraulic system will not secure if HYD BOOST circuit breaker is out.

      1. HYDRAULIC BOOST switch Off
      2. Helicopter Regain Control
      Adjust airspeed as desired to obtain most comfortable control movement level.
      3. Land as soon as Possible

      • Hydraulic system will not secure if HYD BOOST circuit breaker is out.

  3. Chip lights
    1. ENGINE CHIP [NATOPS 12-12]
      Indications: Eng Chip/Clear Chip caution light
      1. Engine instruments - Check for Secondaries
         If secondaries exist:
      2. Land as soon as possible
      If no secondaries exist:
      3. CLEAR CHIP - Press
         If chip light extinguishes:
      4. Note time
      5. Continue flight
         If light remains on:
      6. Land as soon as possible

         If sustained within 30 minutes of first:
      7. Land as soon as possible
         If more than 30 minutes have elapsed since first:
      8. CLEAR CHIP Press
      9. Proceed as with first (Note time, continue flight)

      THIRD CHIP: {if within 50 flight hours of the first}
      10. Land as soon as possible
      11. Do NOT clear chip

      • All chip lights shall be documented on VID/MAF. Chip lights signed off as PASTE do not count toward the total
      number of lights in a 50 hour period {Proper main. troubleshooting requires documentation of which plug has metal}

      Indications: TRANS OIL CHIP caution light

      1. Land as soon as possible {Fly Low (10-20 ft above highest obstacle) and slow (<20 knots), be prepared for gearbox failure (should a gearbox failure occur, your rotors will stop turning and you will fall from the sky) Minimum power changes to minimize xmsn torque}

      Indications: T/R CHIP caution light

      1. Land as soon as possible {Fly high (1000') and fast (80) for weathervaning, be prepared for complete tail power loss}

  4. Fuel system malfunctions
      Indications: Fumes in cockpit, Smoke in cockpit, Equipment Failure

      1. ECS and DEFOG blower OFF
      2. Vents/windows Open
      3. Slip or skid aircraft to eliminate smoke and fumes
      4. Land as soon as possible

      Indications: Unusual fuel usage, Fuel fumes in cockpit
      1. Transmit position and intentions
      2. Unnecessary electrical equipment Secure {In VFR, battery and gen OFF since call made.}
      3. Land as soon as possible
        When on deck:
      4. Shutdown Completed
      5. Helicopter Exit

      If the fuel quantity indicator drops to zero or fluctuates, utilize elapsed time to judge available remaining fuel. Land as soon as practicable.

      Failure of one or both fuel boost pumps will be evidenced by illumination of the Fuel Pump caution light. If one pump has failed, indicated fuel pressure will be normal (4 to 30 psi). The failed pump can be identified by alternately pulling the FUEL BOOST FWD and FUEL BOOST AFT CB's and observing any resulting change in indicated fuel pressure. If both pumps have failed, indicated fuel pressure will be zero. The engine will operate with only one operable boost pump under all conditions of power and altitude. With a dual boost pump failure, however, the engine-driven fuel pump is only capable of supplying fuel to the engine at altitudes below 6000 ft PA

      • With one or both of the boost pumps inoperative, minimum fuel is 20 gallons. A level-flight
      attitude should be maintained to prevent engine flameout that could be caused by the operating submersible pump being uncovered and allowing air to be drawn into the fuel lines or by both boost pumps being inoperative and allowing air to be drawn into the engine-driven fuel pump

      Indications: Fuel Pump caution light, Indicated fuel pressure of zero (duel-pump failure)

      1. Descent - Initiate if above 6000 ft PA and Flight Permits
      2. Fuel pressure and quantity - Note
         If both boost pumps have failed (fuel pressure at zero):
      3. FUEL BOOST circuit breakers pull
      4. Land as soon as possible
         If only one boost pump has failed (fuel pressure 4 -30 psi):
      5. Failed boost pump - Identify
         If unable to identify failed boost pump or Fuel Low caution light is illuminated:
      6. Land as soon as possible
         If able to identify failed boost pump:
      7. Failed boost pump circuit breaker - Pull
      8. Land as soon as practicable

      • With one or both boost pumps inoperative, fuel quantity below 20 gallons shall be considered unusable.
      • Be prepared for complete power loss.
      • Do not pull circuit breakers in an attempt to identify the failed boost pump until below 6000 ft PA
      • If an air leak exists in the fuel lines between the boost pumps and engine, a total loss of boost pump pressure could cause an engine flameout.

    5. FUEL CONTROL FAILURE [NATOPS 14.8] Indications: Erratic Nf , Fluctuating Ng and/or TOT

      1. Collective Adjust (to maintain Nr in operating range)
      2. Twist grip Adjust (to maintain Nf/Ng in operating range)
      3. Land as soon as possible

      • Be prepared for complete power loss.

  5. Engine fire inflight [NATOPS 14.14]
    Indications: FIRE light, Smoke, Flames

    1. Confirm the existence of fire
        If fire exists:
    2. Land immediately
    3. Emergency shutdown Complete after Landing
      If fire not confirmed:
    4. Land as soon as possible

    • Be prepared for complete power loss.

  6. Battery system malfunctions
    1. BATTERY HOT [NATOPS 12-12]
      Indications: Battery case temp 60 +/- 3 °C or higher, BATT TEMP caution light

      1. Battery OFF
      2. Land as soon as possible

    2. BATTERY TEMP [NATOPS 12-12]
      Indications: Battery case temp 54 +/- 3 °C or higher, BATT TEMP caution light

      1. Battery OFF
      2. Flight may be continued.


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  1. All FAM stage checklists and voice reports - PRESTART CHECKLISTS
  2. Normal starting/shutdown procedures - PRESTART CHECKLISTS
  3. Abnormal starts - same as from CPT1
  4. Engine Oil system malfunctions - same as from CPT2
  5. Xmsn Oil systems malfunctions - same as from CPT2
  6. Tach/Gen malfunction - same as from CPT2
  7. TOT malfunction - same as from CPT2
  8. Overtorque/Overtemp/Overspeed - same as from CPT1
  9. Torque malfunction - same as from CPT2

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