Event: CPT 1

Last updated: 19 January, 2004 21:20
 » Report Errors   » Back to the Advanced Gouge list


Skip to: Demonstrate | Introduce | Practice

  1. APU start- APU delivers 28V/400 Amps. The battery is required to be turned off to prevent overcharging. Two thumbs up are required from the pilot (one to connect APU, one to spool up). APU starts should be used when:
    1. Battery has less than 17 V [NATOPS 7-12]
    2. Following a Hot Start if TOT limits have not been exceeded [NATOPS HOT START EP]
    3. During cold weather operations (<15C) [NATOPS 17-5]
    4. All starts for HT-8 unless battery is essential [Squadron SOP]
  2. Use of limits - The flight and engine limitations are a direct result of the flight test programs and actual operational experience. Compliance with these limits will allow the pilot to safely perform the assigned missions and permit the pilot to derive maximum utilization from the helicopter.

    Note - If the aircraft, rotor, or engine limitations are exceeded, record the fact on a maintenance action form and further flight shall not be attempted until the aircraft is inspected by qualified maintenance personnel.
  3. Starter limits- Limit starter energizing time to the following:
    External Power Battery Power
    25 sec ON / 30 sec OFF 40 sec ON / 60 sec OFF
    25 sec ON / 30 sec OFF 40 sec ON / 60 sec OFF
    25 sec ON / 30 min OFF*  40 sec ON / 30 min OFF*

    *Time is less for APU starts because higher amperage spools up starter faster and heats it up quicker.

    Note - If light-off occurs within the first 20 seconds of the start sequence, the starter may be operated for 60 seconds with a 60 second cooling period. Three such attempts can be made in a 30 minute period, then wait 30 minutes to allow the starter to cool. [NATOPS 4.10]
  4. 2C67 curriculum introduction and general information.
    Differences between early TH-57B, late TH-57B
      OLD NEW
    Cargo Hook - YES
    Fuel Capacity 76 Gal 91 Gal
    Refueling Type Gravity Gravity & Pressure (<125PSI)
    ECS Robs 70HP Freon system robs 5HP
    Duct High Temp - Sensor & Caution light
  5. Student responsibilities for CPT cockpits - NA
  6. Use of checklists/voice reports - PRESTART CHECKLISTS
  7. 2C67 scheduling - NA
  8. Location, function, and operation of cockpit gauges, radios, switches, and engine /rotor controls - {Be familiar w/ CPT}
  9. Student checkout on 2C67 operation - NA
  10. RPM beep control - Nf rpm is set by the pilot using the GOV RPM increase-decrease switch located on the collective. The switch operates an electric linear actuator motor, which makes fine adjustments to the governor throttle lever, 96 - 101 + 0.5%. The system is protected by the GOV CONT C/B [NATOPS 2.1.3, Systems 2-22] {There is a lag in system, beep then wait for result. On the start checklist, "Twist grip Full Open Not to Exceed 40%" is a separate item from "Nf/Nr 100%", so Nf can be beeped to 100%. All other times they are joined because Nf has already been set to 100%.}


» Back to the top  

  1. Abnormal starts
    1. Starter failure - Starter OFF. {If Ng rose, but <15% then get APU. No rise may indicate bad starter.}
    2. Igniter failure - {Possible igniter failure or fuel flow problem. If igniter C/B popped, reset after EP, get APU}
                  TOT does not rise after twist grip rotated to FLIGHT IDLE
                  Ng does not rise above 20 percent

                  *1. Twist grip Close
                  *2. Fuel valve OFF
                  *3. Starter Secure
                  *4. BAT switch OFF (when Ng is zero) {At Ng zero, a valve opens which empties fuel from engine}
    3. Hung start
      HUNG START [NATOPS 13.4]
                  Ng rises slowly and stabilizes below 50 percent
                  TOT rises more slowly than normal
                  *1. Twist grip Close
                  *2. Fuel valve OFF
                  *3. Starter Secure After TOT Stabilizes Below 400 C
                  *4. BAT switch OFF {When rotors stop for strobes}
    4. Hot start
      HOT START [NATOPS 13.3]
                  TOT exceeds limits
                  TOT light illuminates

      Note - Any of the following indications, particularly when combined, indicates an increased potential for a hot start and may necessitate an aborted start to preclude an overtemp:
                  Excessive rise in TOT
                  TOT accelerates through 840 degrees
                  Battery voltage stabilized below 17 volts on starter engagement

                  *1. Twist grip Close
                  *2. Fuel valve OFF
                  *3. Starter Secure (After TOT stabilizes at 400C or below)
                  *4. BAT switch OFF {When rotors stop for strobes}

      Caution - Do not allow the TOT to rise above 810 C for more than 10 seconds or 927 C for any length of time.
      Note - Utilize APU for subsequent start attempts after aborted starts if TOT limits have not been exceeded.
    5. Engine fire on start
                  FIRE warning light
                  Indication from fire guard

                  *1. Twist grip Close
                  *2. Fuel valve OFF
                  *3. BAT OFF
              © *4. Rotor Brake Engage
                  *5. Helicopter EXIT and use the fire bottle to extinguish the fire or get clear of the aircraft
      Warning - After exiting aircraft, beware of rotor blades.
    6. Abort Start PROCEDURES:
      *1. Twist grip Close
      *2. Starter Secure After TOT Stabilizes Below 400 C
      *3. BAT switch OFF {When rotors stop for strobes}
  2. Post shutdown fire/internal - {May be a slow rise to 400, watch carefully because there is also a rise in normal shutdown}
    POSTSHUTDOWN FIRE (INTERNAL) [NATOPS 13.6]: A post shutdown fire is an internal engine fire that occurs in an engine that is stopped or coasting down.

                TOT rises above 400 C
                Flames or smoke coming from engine

                *1. Starter Engage
                *2. Fuel valve OFF
                *3. Igniter C/B Pull
                *4. Starter Secure After Fire is Extinguished


» Back to the top

  1. Anti-Ice operation
    Operation of the engine during icing conditions could result in ice formation on the compressor front support. If ice were allowed to build up, air flow to the engine would be restricted and engine performance decreased. The engine has an anti-icing system to prevent ice formation on the compressor front support. The anti-icing system includes an anti-icing valve mounted at the 12 o'clock position the front face of the diffuser scroll, two stainless steel line between the anti-icing valve and the compressor front support, and passages within the compressor front. The pilot must turn on the anti-icing system when encountering icing conditions. When this system is on, hot compressor discharge air is directed to two ports on the compressor front support. Hot air flows between the walls of the outer skin into the hollow radial struts through the struts, and between the walls of the hub. The flow of hot anti-icing air keeps the temperature of the compressor front support above the freezing point of water. [NATOPS 2.1.1, Systems 2-18]

    Note- Engine anti-icing will remain in the last energized position in the event of an electrical failure.

    When anti-ice switch is placed ON, TOT should rise 10-15C. When placed OFF, TOT should drop 1-10C. [NATOPS Ch. 10, Pretakeoff checklist (3), item I ]

    {TOT rises when anti-icing system is activated because it uses part of the 75% compressor discharge cooling air to heat the front supports}

    ICING [NATOPS 14.13]: Operation of the engine during icing conditions could result in ice formations on the compressor front support. If ice were allowed to build up, air flow to the engine would be affected and engine performance decreased. Every effort must be made to stay clear of known icing conditions. The anti-icing system in this helicopter is to be used as a preventive measure only. Once ice has accumulated, the anti-ice system cannot be used as a corrective measure (will not de-ice). Intentional flight into any known icing conditions (<4 C in visible moisture) is prohibited. For inadvertent flight in icing conditions:

                1. Eng anti-icing ON
                2. Pitot Heat switches Heat
             ©3. Alternate static port As req.
           If unable to remain clear of icing conditions:
                4. Land as soon as possible

    Warning: Monitor engine instruments and be prepared for partial or complete power loss

    When the OAT is below 10 C and flight into visible moisture is likely, anti-icing and pitot heat shall be on. [RWOP 1012]

                Flight into icing conditions is prohibited (<4C w/ visible moisture} [NATOPS ICING EP]
                Anti-Icing shall be checked in Prestart if below 10 C [NATOPS 7-14]
                Anti-Icing shall be on if: Below 10C and visible moisture [RWOP 1012]
                5 min after engine wash for maximum drying [NATOPS 7-14]
                Anti-icing is preventive only
                When placing Anti-icing on check for rise in TOT
  2. Normal starting/shutdown procedures - PRESTART CHECKLISTS
  3. FAM stage communication procedures - PRESTART CHECKLISTS
  4. FAM stage checklists - PRESTART CHECKLISTS


» Back to the top


» Back to the Advanced Gouge list
» Contact the webmaster, Bryan Weatherup

DISCLAIMER: The information provided on this page is to be used only to assist Student Naval, Marine, Coast Guard Aviators and U.S. Air Force Student Pilots. It is by no means meant to replace or supercede the knowledge presented in NATOPS, OPNAV 3710.7T, Flight Training Instructions, FLIPS, or any other official Navy, Marine, Coast Guard or U.S. Air Force publication. Knowledge of these documents is considered paramount to flight safety. Any unauthorized use of the information on this page in an actual flight (without reference to the official publication) is strictly prohibited. Viewing web pages listed above constitutes acceptance of all responsibility for flight safety by you, the user. The author of this page assumes no responsibility for the completeness of these documents or their use in Aviation training.

If you find discrepencies in the information here, please contact me. This is NOT an official Navy web site. All opinions and statements are exclusively those of the authors and do not reflect the views of the Department of Defense, The United States Navy, The United States Marine Corps, The United States Coast Guard or the The United States Air Force.