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United States Army Aviation Center of Excellence Fort Rucker by mikesanye

VIEWS: 48 PAGES: 30

									                       United States Army Aviation Center of Excellence
                                    Fort Rucker, Alabama
                                      SEPTEMBER 2010




                                       STUDENT HANDOUT

                              TITLE: CH-47D ROTOR SYSTEMS

                                   FILE NUMBER: 011-2104-2




PROPONENT FOR THIS STUDENT HANDOUT IS:

    110th Aviation Training Brigade
    ATTN: ATZQ-ATB-AD
    Fort Rucker, Alabama 36362-5000




FOREIGN DISCLOSURE RESTRICTIONS: This product/publication has been reviewed by the product
developers in coordination with the Cargo Utility Branch/ Ft. Rucker foreign disclosure authority. This
product is releasable to students from all requesting foreign countries without restrictions.




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                                   CH-47D ROTOR SYSTEMS

                                       STUDENT HANDOUT


TERMINAL LEARNING OBJECTIVE (TLO):

Action: Describe the components, operational characteristics, functions, emergency procedures, and
limitations of the CH-47D Rotor System.

Conditions: In a classroom, given a CH-47 rotor hub on a stand, CH-47 rotary wing cutaway, CH-47
swashplate assembly, Operators manual, and a student handout.

Standards: Correctly answer in writing, without reference, four of six questions pertaining to
components, operational characteristics, limitations, and functions of the CH-47D Rotor System, In
Accordance With (IAW) TM 1−1520−240−10 and the student handout.

Safety Requirements: None.

Risk Assessment Level: Low.

Environmental Considerations: None.

Evaluation: Each student will be evaluated on this block of instruction during the third written
examination. This will be a criterion type examination requiring a GO on each scored unit. You will have
90 minutes for the exam.




                                                    3
1. Learning Step/Activity 1      List the components of the rotary wing head and control systems.

   a. Slider Shaft.




        (1) Forward is mounted on top of the forward transmission.

        (2) Aft is mounted on the aft vertical shaft thrust bearing.

        (3) Provides for the alignment of the swashplate assembly.

   b. Swashplate assembly.

        (1) Mounted on the slider assembly.

        (2) Provides input to the rotor head via the pitch change links.

   c.   Yoke Assembly

        (1) The forward yoke is attached to the forward transmission upper case.

        (2) The aft yoke assembly is attached to the fuselage in the aft pylon at STA 534, left-hand side.

        (3) Act as a pivot point whenever the swashplate is tilted left or right or moved vertically.

   d. Longitudinal Cyclic Trim Actuator (LCT).

        (1) Forward LCT located on the outboard side of the fixed ring between the forward swashplate
            and the yoke assembly.

        (2) Aft LCT located on the inboard side of fixed ring between the aft swashplate and the yoke
            assembly.

        (3) Provides inputs into the rotor system using commands from the AFCS or manually from the
            pilot.



                                                      4
e. Fixed Link.

     (1) Forward fixed link mounted on the inboard side of the forward swashplate.

     (2) Aft fixed link mounted on the outboard side of the aft swashplate.

     (3) Has a strain gage that measures the stresses on the rotor system and sends the signal to the
         CGI. The forward fixed link sends its signal to a signal conditioner unit located in the front of
         the forward pylon and then to the signal processor in the aft pylon. The aft fixed link sends its
         signal to the signal processor in the aft pylon and the highest signal of the two is sent to the
         CGI gage in the cockpit.

f.   Drive Arm.

     (1) Mounted between the swashplate and the weather protective cover.

     (2) Keeps the rotating ring of the swashplate aligned with the rotor head.

g. Pitch Change Link (PCL).




     (1) Mounted between the rotating ring of the swashplate and the rotor head.

     (2) Provide the direct input of pitch into the rotor head.

h. Weather Protective Cover.

     (1) Mounted above the swashplate assembly, just below the rotor head.

     (2) Keep rain, ice and snow from entering the upper transmission areas.

i.   Centrifugal Droop Stops.

     (1) Located only on the aft rotor shaft assembly, just below the rotor head.

     (2) Reduce the amount of travel (flap) for the aft blade assemblies when operating at low RPMs.




                                                   5
     j. Fixed Droop Stops

          (1) Hardened steel blocks bolted to each pitch-varying shaft, below the horizontal hinge pins

          (2) Forward fixed droops prevent the rotor blades from drooping low enough, at low Rotor RPM,
              to strike the helicopter or the ground.

          (3) Aft fixed droop stops on the aft rotor head protect the rotor head and provide a surface for the
              interposer block to contact.

WARNING: Stops are not interchangeable between the forward and aft rotor heads. Damage to the
         rotor system or helicopter can occur if forward and aft droop stops are interchanged.

j.   Rotor Head.




          (1) Forward mounted on the forward rotor shaft.

          (2) Aft mounted on the aft vertical shaft.

          (3) Transmit the torque from the transmission to the rotor blades.

          (4) Transmit the pitch change from the pitch change link to the rotor blades.

     k.   Damper (Shock Absorber).

          (1)   Mounted between the rotor head and blade assemblies.

          (2)   Controls the rate and limits the amount of lead and lag for the blade assemblies.

     l.   Rotor Blade.

          (1)   Three blades are mounted to each rotor head assembly.

          (2)   Provides the lift for the helicopter.

          (3)   Each blade weighs approximately 350 pounds.

     m. Rotor RPM Indicator.

          (1)   Located on the pilots and co-pilots instrument panels.

          (2)   Indicates Rotor RPM (RRPM).



                                                        6
2. Learning Step/Activity 2 - Describe the components, operational characteristics, and
   functions of the rotary wing control system.

a. Slider Shaft.




   (1) The slider assembly is used to keep the swashplate vertically aligned.

   (2) Includes stops at the top and bottom to limit the amount of vertical travel of the swashplate.

   (3) The slider is coated with a Tungsten Carbide layer to reduce the amount of drag on the
       bearings inside of the swashplate.

   (4) During preflight check for scratches in the coating, dents, or cracks on the sliding surface.

b. Swashplate Assembly.




   (1) Flight control movement, manual or automatic, result in vertical or tilting movement of the
       swashplate, this transmits the movements of the upper dual boost and Longitudinal Cyclic
       Trim (LCT) actuators to the rotating components attached to the rotor head.




                                                7
(2) The swashplate is broken down into the following components:




   (a) Stationary Ring.

       1. The forward and aft stationary rings are made from different materials, the forward is
          made from aluminum and the aft is made from steel.

       2. Provides the attachment points for:

           a. Pivoting upper dual boost actuator.

           b. Swiveling upper dual boost actuator.

           c.   LCT actuator.

           d. Fixed link.

   (b) Rotating Ring.

       1. Converts non-rotating pitch control inputs into rotating pitch control inputs using the
          Pitch Change Links (PCL).

       2. Provides the attachment points for:

           a. Three pitch change links.

           b. Drive arm assembly.

       3. Two single and one double interrupter are installed on the bottom of the rotating ring
          to provide the location of the target blade (green) to the track and balance equipment
          via a magnetic pickup.

   (c) Ball Bearing.

       1. Separate rotating and the non rotating components.

       2. Bearing is held in place by a lower and upper bearing retainer.

       3. Lubricated by grease fitting on the lower portion of the swashplate.



                                            8
             4. Grease is held in the bearing by an upper retainer mounted to the rotating ring and
                the lower grease seal mounted to the stationary ring.

         (d) Ball Spherical Bearing (Uni-Ball).

             1. This bearing provides the vertical movement on the slider shaft and the tilting
                movement about the vertical axis.

             2. Dry Teflon bearing rings are located on the inside of the ball, no other lubrication is
                required. The bearing rides on the slider assembly.

                 a. The bearing sets consist of a three piece matched bearing assembly which are
                    glued to the upper and lower section of the ball assembly.

                 b. Three retainers are used to maintain the proper vertical spacing of the two
                    bearing sets.

             3. The spherical ball is fit into a set of two Dry Teflon bearings inside the rotating ring,
                which allows the stationary ring to tilt independently of the ball assembly.

c.   Longitudinal Cyclic Trim (LCT) actuators.

     (1) The LCT system reduces fuselage negative angle of attack as forward airspeed is increased,
         thus reducing fuselage drag.

     (2) The system also reduces blade flapping which results in lower stresses on the rotor shafts.

d. Fixed Link provides 3 functions.

     (1) When the LCT operates it acts as the pivot point for the swashplate.

     (2) When the swashplate is moved by the upper dual boost actuators the fixed link keeps the
         pressure and strain off the gears within the LCT.

     (3) The fixed link houses the strain gage for the cruise guide indicating system.

         (a) The fwd fixed link provides its signal to the conditioner which is then sent to the processor
             in the aft pylon.

         (b) The aft fixed link provides its signal to the processor.

         (c) The larger of the two signals is sent to the Cruise Guide Indicator in the Cockpit.




                                                    9
e. Drive collar and drive arm assembly.




   (1) The drive collar transmits the torque to the swashplate through the drive arm assemblies.

       (a) The drive collar is master splined to align with the rotor drive shaft.

       (b) A flange is located on the drive collar for installation of the weather protective cover.

       (c) Drive collar lugs are used to connect the upper drive arm.

       (d) Teflon, fabric bearings are used at each joint.


   (2) The drive arm assembly drives the rotating ring of the swashplate.




       (a) Upper drive arm is attached between the collar and the lower drive arm.

           1. Upper attachment point contains stainless steel bushings.




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                 2. Lower attachment point contains Teflon bearings.

                 3. Upper and lower bolts are positive retention bolts.

NOTE: Positive retention bolts have a pawl at threaded end of bolt shank. The pawl is spring-loaded to
an extended position. When extended, the pawl prevents the nut from being removed. Finger pressure
compresses the pawl for removal of the nut and for removal of the bolt from the parts.

             (b) Lower drive arm is attached between the upper drive arm and swashplate to forming a
                 hinge.

                 1. Upper attachment point contains stainless steel bushings.

                 2. Lower attachment point contains a shrink fit bushing (spherical bearing).

                 3. Lower attachment bolt is a impedance type bolt that requires a cotter pin for the nut
                    and a safety on the head.

NOTE: Impedance bolts have either spring-loaded balls or a spring ring on the bolt shank above the
threads. These retaining elements extend beyond the diameter of the bolt and prevent it from sliding from
the parts. This is the type most commonly used in the flight controls.

    f.   Pitch Change Links (PCL).




         (1) PCLs are adjustable links that are mounted between the swashplate and the pitch housing
             arms of the rotor head.

         (2) The PCL’s control the blade tip plane.




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   (3) The PCL location is identified by the color on the associated pitch housing arm, i.e... red,
       yellow, or green.




       (a) The upper rod end is a single piece with a drilled hole for a locater pin.

       (b) The lower rod end is a single piece with the ends slotted to fit the locater pin in the upper
           rod.

       (c) This engagement aligns the rod end at the required angle.

       (d) The rod end are joined by a turnbuckle which when rotated lengthen or shorten the PCL,
           which is held in place with a safety.
       (e) Check (Jam) nuts and indicator sleeves are used for locking in the adjustments and
           require a cotter key.

   (4) If the pitch links are adjusted for any of the following reasons a test flight will be required.

       (a) Ground track.

       (b) Hover.

       (c) In-flight track.

       (d) Balance.

       (e) Autorotation.

       (f) Pitch stick position.

g. Weather Protective Cover (rain shield).

   (1) Installed over the rotary-wing head controls.

   (2) The cover is bolted to and rotates with the drive collar.

   (3) Watertight boots seal the openings in the cover where the PCLs pass through.




                                                  12
h. Centrifugal Droop Stop assembly.




   (1) Only installed on the aft rotor system.

   (2) Allow a droop angle for the aft blades of 5.5° to 6° when the rotor RPM is above 67%.

   (3) Reduce the droop angle for the aft blades to 1.25 to 1.75° when the rotor RPM is below 56%.

   (4) Components of the centrifugal droops stops are:

       (a) Mounting plate, this is master splined to the aft rotor shaft, and installed below the rotor
           head assembly.

       (b) Interposer Block, this is the actual stop for the fixed droop stops on the rotor head pitch
           varying shaft.
       (c) Balancing Arm, mechanical arm that is connected between the weight and the interposer
           block routed around the horizontal hinge pin.

       (d) Weight, is attached to the top of the balancing arm, and is used to pull the arm outward
           as the RRPM increases above 67%.

       (e) Limiters are two interconnected loops that restrict the distance the weight and arm
           assembly can extend outward.

       (f) Springs are used to pull the weight and arm assembly back into place as the RRPM
           decreases below 56%.




                                                 13
         (5) Operation of the centrifugal droop stops.

WARNING: If an interposer block or rotor blade droop stop is not in place, the flight engineer will notify
the pilot in command. All non-crewmembers will evacuate the aircraft to a safe position. If possible, crew
will contact maintenance and attempt to engage interposer block with a high pressure water stream or
prepare aircraft for shutdown in such a way as to minimize damage to the aircraft and components and
prevent injury to personnel. If interposer blocks appear to be in place, the flight engineer will clear the pilot
to shut down the first engine. After the first engine is shut down, the flight engineer will observe the rotor
blade tip path of the forward and aft rotor heads. A rotor blade drooping significantly lower than the other
blades indicates a missing droop stop. In this case the remaining running engine condition lever (ECL)
should be advanced until sufficient rotor RPM is achieved to lift rotor blades off of droop stops to insure
no blade contact with airframe and maintenance contacted to prepare aircraft for an emergency shutdown
that will minimize damage to aircraft and injury to personnel.

             (a) At low RRPM, the springs hold the arms close to the hub, keeping the interposer blocks
                 between the hub and the pitch varying shafts to limit blade droop angle.

             (b) As RRPM increases, centrifugal force causes the arms to move out against the spring
                 tension.

             (c) This moves the block out from between the hub and the shafts to allow more freedom for
                 the blades to flap.


3. Learning Step/Activity 3 - Describe the components, operational characteristics, and functions
   of the rotary wing head.

    a. Two fully articulated rotor heads are installed on the helicopter, allowing each blade to flap,
       feather, lead, or lag.

    b. The rotor head transmits torque from the rotor shafts to the blades.

    c.   The forward head weighs 642 pounds while the aft head weighs 644 pounds.

    d. The components of the rotor head are as follows:

         (1) Rotor hub assembly.




                                                       14
    (a) The hub is master splined to the rotor shafts.

    (b) Provides the mounting base for the components of the rotor head.

(2) Horizontal Hinge Pin.

    (a) Installed in the hub assembly.

    (b) Allows the blades to flap.

    (c) Supported and allowed to rotate using two set of bearings.

    (d) Horizontal hinge pin is aligned in the hub using thrust washers and shims.

    (e) The horizontal hinge pin is held in place using two caps which are locked by beams and
        key assembly.

(3) Tie Bar.




    (a) Located between the hub, inside the horizontal hinge pin and the outboard end of the
        pitch varying housing.

    (b) Attached at both ends by a pin and bolt assembly.

    (c) Laminated steel bar consisting of 32 layers.

    (d) Performs dual purposes:

        1. Holds the pitch-varying housing to the rotor hub.

        2. Allows the pitch-varying housing to rotate around the pitch-varying shaft, changing
           the pitch in the rotor blades.

(4) Pitch–Varying Shaft.

    (a) Mounted to the horizontal hinge pin.

    (b) Provides the mount for the pitch-varying housing.




                                            15
           (c) Fixed droop stops are installed to the bottom of the pitch-varying shaft below the
               horizontal pin.




               1. Hardened steel blocks.

               2. Not interchangeable between the forward and the aft heads.

               3. Stenciled for proper installation using “FWD ROTOR BOTTOM” or “AFT ROTOR
                  BOTTOM”.

               4. During preflight check for proper Installation and that the mounting bolts have the
                  required safety.

NOTE: Droop stop pounding is a loud thumping noise or vibrations. It can be caused by exceeding
control limitations and may damage the droop stops.

           (d) At rest the forward fixed stops contact the hub allowing the blades to droop at an angle of
               4.5° to 5°.

           (e) At rest the aft fixed stops contact the interposer blocks restricting the droop 1.25° to
               1.75°.

       (5) Pitch-Varying Housing (PVH).




                                                    16
       (a) Connected to the pitch-varying shaft by the tie bar which is pinned to the pitch-varying
           shaft and hub.

       (b) Allows for the blades to feather by rotating around the pitch-varying shaft to change the
           blade pitch.

       (c) Provides mounts for the pitch change links, damper, blade, and the lighting protection
           cables (Bonding Jumpers).

       (d) Contains two sets of bearing sets:

           1. One set is installed in the housing that allows the pitch-varying housing to rotate
              around the shaft giving flap. The set consists of two bearing sets one at the inboard
              end underneath the color stripe on the housing, and one on the outboard end near
              the vertical hinge pin.

           2. The other set is located in the pitch-varying housing arms, to allow the vertical hinge
              pin to rotate, which allows the blades to lead and lag. The set consists of two bearing
              sets one in the upper arm and the other in the lower arm.

       (e) Color coded based on the master spline for ease of identification, Red, Yellow, and
           Green.

   (6) Vertical Hinge Pin.

       (a) Attaches the blade to the pitch-varying housing.

       (b) Tapered from the top to the bottom. This design allows the pin to be torque properly.
           The tapered design also prevents it from falling through the pitch-varying housing arms
           if the upper nut was to come loose.

       (c) Allows the blade to lead and lag.

e. Rotor Head installation.




   (1) Rotor head is installed by aligning the master spline on the head with the master spline on
       the rotor shaft.



                                                17
     (2) The hub retaining nut holds the head down in place and is installed with a torque of 6000 foot
         pound of force.

     (3) The hub retaining nut is locked in place with a special tang washer that lock into the rotor
         shaft and the retaining nut. The tang washer is held In place with a retaining ring.

     (4) Hub retaining nut is covered by a cover and a retainer which is screwed in place.

f.   Oil System.




     (1) Each rotor head contains seven separate oil lubrication systems

         (a) The central oil tank (hub oil tank) on the hub lubricates the six horizontal hinge pin
             bearings and holds 1.07 quarts.

         (b) Three pitch varying shaft tanks (potato head) lubricate the pitch varying housing bearings
             in the shaft only and holds .44 quarts.

         (c) Six vertical hinge pin tanks (3 separate systems) lubricate the vertical hinge pin bearings,
             which hold a total of .62 quarts.

             1. Oil flows from the top tank through a oil manifold (transfer) tube located on the back
                of the pitch-varying housing arm.

             2. When checking the level of these tanks ensure that the bottom tanks are full, if they
                are not full the transfer tube may be clogged, restricting the oil flow to the lower
                bearing set.

     (2) Serviced with MIL−L−7808 (silver can).

     (3) When checking the fluid levels on pre-flight half way up the sight glass equates to full.




                                                  18
g. Blade Dampers (Shock Absorbers).




   (1) Attached to the pitch varying housing and blade root end.

   (2) Limits the amount of lead and lag.

   (3) Controls the rate of lead and lag.

   (4) Filled with MIL-5606 non-fire-resistant hydraulic fluid.

       (a) Use the sight glass to check fluid level.

       (b) Level should be in the middle of the site glass with the blade over the tunnel cover.

   (5) Shock absorber vent valve allows the damper to vent in cold weather.

       (a) Closed at temperatures above -1°C.

       (b) Opened or closed at temperatures between -1°C and -18°C.

       (c) Open at temperatures below -18C.

       (d) Installed with proper side up (AFT or FWD) keeping the vent on the back side in
           reference to the direction of rotation.




                                                19
4. Learning Step/Activity 4 - Describe the components, operational characteristics, and functions
   of the rotary wing blade.

   a. Each head has three composite fiberglass, titanium, and Nomex blade assemblies.




   b. Each blade has a overall length of 330.5” and a width of 32" also called the chord and has a
      weight of 350 to 360 pounds.

   c.   The main structural component of the blade are:




        (1) D shaped fiberglass spar.

        (2) A titanium nose cap covers the leading edge of the spar.

        (3) A nickel erosion cap is bonded to the nose cap along the outboard 54".

            This cap protects the part of the blade most vulnerable to erosion.




                                                    20
(4) A fairing assembly of Nomex and fiberglass.

    (a) Bonded to the trailing edge.

    (b) Constructed of nomex honeycomb core, covered with a fiberglass skin.

(5) Trim Tab.

    (a) Installed at the mid portion of the blade on the trailing edge.

    (b) Used during track and balance to adjust the blade flight path at higher airspeeds.

(6) Kevlar filament windings.

    (a) Located on the root end of the blade.

    (b) Used to hold on the composite lag damper bracket to the blade.




(7) Blade attachment point must be checked for proper bushing position.

    (a) Bushing should not be extended or popped away from the blade.

    (b) If the bushing is popped then it must not rotate.

(8) Composite sleeve.

    (a) Installed in the root end of the blade.

    (b) Used for strength due to the rotation friction forces of the vertical hinge pin.




                                              21
   (9) Balance Weights.




       (a) Installed in the nose of the blade and in the tip cap.

       (b) Used to balance the blade both laterally and longitudinally.

   (9) Tracking Weights.

       (a) Installed in the tip end of the blade.

       (b) Tungsten tracking weights are used for adjusting the weight of the blade due to a blade
           repair.

       (c) The weights on the removable tip cap are for blade balancing during the track and
           balance portion of the test flight.

d. Lightning Protection.




   (1) Wire mesh screens are imbedded in the fiberglass skin at the tip of the blade and where the
       trim tab is installed for lightning protection.

   (2) The titanium nose cap transfers any lighting strike from the wire screens to the lighting
       protection strips.


                                                    22
(3) The lighting protection strips bridge the gap between the nose cap and the bonding cable
    straps.

    (a) The strips are located on each side of the blade near the root end.

    (b) Check on preflight for proper bonding of the strips, to ensure the strips are not peeling
        away from the blade.

    (c) Evidence of a lighting strike is when the lighting protection strip has burn apart, similar to
        a fuse.


(4) Bonding Jumpers.




    (a) Complete the path from the lighting protection strip to the rotor head.

    (b) There are two for each blade.

    (c) Cables attach to the brackets at the top and bottom of the vertical hinge pin oil tank
        manifold tube on the rotor head.




                                             23
5. Learning Step/Activity 5 - Describe the operational characteristics of the Rotor Tachometer.

   a. There are two rotor tachometers mounted on the pilot and copilot instrument panels.




   b. Indicated in percent of rotor revolutions 100% is equal to 225 RPM.

        (1)   Small needle indicates from 0 to 60%.

        (2)   Large needle indicates from 60 to 130%.

   c.   The rotor speed signal is supplied by the Permanent Magnet Generator (PMG) in the main
        generators on the aft transmission.




        (1) Copilot's indicator is supplied from the No.1 generator.

        (2) Pilot's indicator is supplied from the No.2 generator.

   d. Electrical power is through the ROTOR TACH circuit breaker on each PDP.



                                                      24
6. Learning Step/Activity 6 - Describe the rotor system limitations and emergency procedures.

NOTE: Refer to Chapter 5 for current rotor limitations and emergency procedures.

    a. Rotor RPM Limitations:




NOTE: The red lines at 96% and 115% are markings on the inside of the gage that have been used for
previous limits in either the Delta model or Charlie model Chinook. Since they are on the inside of the
gage and can’t be readily changed a comment of disregard is noted in the operators check list.

        (1) 91% is the minimum transient operating limit.

            (a) Generators come off line at 82% to 85% RRPM.

            (b) Generators come back on line at RRPM 88% to 91%.

        (2) 97% to 101% is the normal operating range.

        (3) 102% to 105 % Transient.

        (4) 106%. MAX Transient Power-On.

        (5) 108%. MAX      During Autorotation Power-Off.

            (a) Should 108% power off be inadvertently exceeded, no entry needs to be made on the DA
                Form 2408-1, unless the rotor system accelerates to 111% or above.

            (b) Even though no action is required when RRPM exceeds 108% power off, but remains
                less than 111%, willful operation should not be conducted in this range.

        (6) 111%. MAX Transient.




                                                   25
    b. Other Limitations.

        (1) Rotor, Transmission, and Drive Systems. (warning):            Page 9-16, Para. 9-30.

WARNING: “If an interposer block or rotor blade droop stop is not in place, the flight engineer will notify
the pilot in command. All non-crewmembers will evacuate the aircraft to a safe position. If possible, crew
will contact maintenance and attempt to engage interposer block with a high pressure water stream or
prepare aircraft for shutdown in such a way as to minimize damage to the aircraft and components and
prevent injury to personnel. If interposer blocks appear to be in place, the flight engineer will clear the pilot
to shut down the first engine. After the first engine is shut down, the flight engineer will observe the rotor
blade tip path of the forward and aft rotor heads. A rotor blade drooping significantly lower than the other
blades indicates a missing droop stop. In this case the remaining running engine condition lever (ECL)
should be advanced until sufficient rotor RPM is achieved to lift rotor blades off of droop stops to insure
no blade contact with airframe and maintenance contacted to prepare aircraft for an emergency shutdown
that will minimize damage to aircraft and injury to personnel.”


        (2) Thunderstorm Operation:                                               Page 5-15, Para.5-32.

             “To ensure adequate lightning strike protection, the lightning protection cables and strips
             must be installed and intact on all rotor blades. If any lightning cables or strips are missing or
             broken, avoid flight in or near thunderstorms, especially in areas of observed or anticipated
             lightning discharges.”




                                                       26
                            Appendix C - Practical Exercises and Solutions

                                        CH-47D ROTOR SYSTEM

                                PRACTICAL EXERCISE PROCEDURES


NOTE: This practical exercise covers the instruction you received in this handout. Completion is
optional, but strongly encouraged.


1. Which actuators are attached to the non rotating ring of the swashplate?


2. What drives the outer ring of the swash plate?


3. What can cause droop stop pounding?


4. When pre-flighting the central hub oil tank, how much oil should show in the sight glasses?


5. How will droop stop pounding be indicated to the pilots?


6. What component of the rotor head allows the blades to lead and lag?


7. What controls the amount of lead and lag?


8. What is the maximum transient rotor RPM with the engines driving the rotors?


9. Where are the Lighting protection strips located?


10. What is the maximum transient rotor RPM?


11. What environmental condition must be avoided, if any, if the lightning protection strips or bonding
    cables are missing or broken?


12. A fully articulated heads means that each blade can _______, _________, _______ and
    ___________.


13. What RPM can be used for normal operations?




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28
                                       CH-47D ROTOR SYSTEM

                                   PRACTICAL EXERCISE SOLUTIONS


1. Two upper dual boost actuators and one LCT actuator.

2. Drive arm assembly.

3. Exceeding ground control limits.

4. They should show Half Full

5. Thumping noise and vibrations

6. Vertical hinge pin.

7. Shock absorbers.

8. 106%

9. Top and bottom of each blade

10. 111%

11. Flight near thunderstorms.

12. Flap, Feather, Lead, and Lag

13. 97% to 101%.




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