|HMU Functions|| 1. Rapid engine transient response through collective compensation|
2. Auto fuel scheduling for engine start
3. Ng overspeed (110 ±2%)
4. Ng governing (T2, P3, Ng)
5. Acceleration limiting (PCL's)
6. Flameout / comp stall protection (VG / Start bleed)
|Some fuel is tapped off to operate various servos in the HMU for the following:|| 1. Positioning a metering valve to ensure proper fuel flow|
2. Positioning a servo piston to actuate VG servo and start bleed valve
3. Amplify various signals that influence fuel flow and VG servo position
|The HMU responds to the PCL for:|| 1. Fuel shutoff|
2. Setting engine start fuel flow with auto acceleration to ground idle
3. Setting permissible Ng up to max
4. Fuel priming
5. DECU Lockout
*The HMU also responds to T2, P3, and Ng
|ODV Functions:|| 1. Fuel to injectors|
2. Purges fuel on shutdown (prevents coking injectors)
3. Traps fuel upstream keeping fuel/oil heat exchanger full, preventing need for fuel priming
4. Np overspeed / Hot Start prev. routes fuel back to HMU
|DECU Functions: (4N CHEF TASTED)||1. 400 Hz airframe backup power|
2. Np Governing (100%)
3. Np Overspeed (120%)
4. Np Overspeed test (re-reference to 96% Np)
5. Ng Decay relight feature (igniters 5 sec, disabled <62% Ng)
6. Contingency power (891°±10)
7. Hot Start Prevention (>900° with Ng<60% / Np<50% until 300 or 25 sec)
8. ENG Speed Trim (96-101% Np)
9. Fault Diagnostic (displays fault code numerically in TQ indicator for 1 min when: Ng<20%, Np<35%, Other engine is shutdown, 400 Hz available.
10. TGT Limiting (839°±10)
11. Auto Ignition (Np<120, 5 sec)
12. Signals - cockpit (Np, TGT, TRQ to DTC)
13. Transient Droop Improvement
14. Engine Load Sharing (Matched TRQ)
15. DECU Lockout (deactivates: TGT limiting, Np Gov, Load Sharing)
|The control parameters of the DECU are:||1. Np Sensing (governing)|
2. Np overspeed and torque sensing
3. TGT monitoring
Inputs from the cockpit:
1. ENGINE SPD TRIM switch
2. CONTGCY PWR switch
3. ENG OVERSPEED TEST A and B buttons
Inputs from the helicopter:
1. Torque from other DECU
2. Np Demand
3. 400-Hz backup power
4. HMU (LVDT)
Signals to cockpit:
|ENGINE OIL SYSTEM||A self contained, pressurized, dry sump system with 6 main bearings, w/ 2 sets of jets per bearing. Bearings 1 & 2 support the output shaft, 3 & 4 the gas generator section, and 5 & 6 the power turbine section. Sump A is bearings 1-3, Sump B bearing 4, and Sump C bearing 5 & 6.|
Impending bypass PDI has a thermal lockout < 38°
Cannot over-service engine oil
At add mark: Add 2 qts.
Oil hot - wait 20 min to service
All engine oil lights are triggered by VIDS
|ANTI-ICE SYSTEM Indications of malfunction:|| 1. Illumination of ENG ANTI-ICE ON with above 90% Ng (or 94% Ng if OAT is 15° or greater)|
2. No Illumination of ENG ANTI-ICE ON when Ng drops below 88%
3. No illumination when switches ON
4. No rise in TGT when ENG ANTI-ICE selected ON
|Three ways to anti-ice the engine:||1. Vent bleed air into the Swirl Vanes and Engine Inlet Guide Vanes by the anti-ice/start bleed valve.|
2. Vent bleed air into the airframe engine inlet by the engine inlet anti-ice valve
3. Continuously pump engine oil through scroll vanes providing cooling to the oil and anti-icing of the main frame. All air heated is vented overboard through the IPS.
|TRANSMISSION SYSTEM||Main XMSN - 3° forward tilt|
Wet sump system with 2 pumps that work in parallel
Input Module contains freewheeling unit
Accessory module mounts and drives generators and hyd pumps
MAIN / ACC 1 &2 / INPUT 1 & 2 / INT / TAIL have identicalchip detectors all have fuzz burn off feature when < 140° C, MAIN has 30 second delay to eliminate false positives, and TAIL and INT illuminated a Oil Temp Caution when ≥ 140 C
Separate from vertical instruments
LOW PRESS Sensor < 14 psi (Left access mod / furthest point from pump)
OIL HOT sensor > 117° C (immediately outside oil cooler)
Nr sensor (TDI): Left accessory module
Nr sensor (vertical instruments): Right accessory module
CHIP IBIT Test - 2 min test that checks circuitry and chip detectors. First 40 secs of test the WCAs and Master Caution lights will not correctly respond
|FUEL SYSTEM||590 useable Gal (JP-5/F44 4012 lbs, JP-8/F34 3953 lbs).|
Interconnect: 270 lbs per side
Left Cell - single point refuel/defuel, gravity refuel, HIFR, vent, & 2 high level shutoff floats
Right Cell - APU fuel line, dump system, and vent
Lower 1/3 of cells are self sealing.
Fuel quantity is measured in each cell by a capacitance-type sensor.
|EXTERNAL TANKS||Crashworthy, ballistically hardened 120 gal (~800 lbs) tanks |
Self sealing breakaway valves prevent spillage in case of separation
Fuel level monitored by single gauge probe that provides signal to MDs/FDs and FMCP.
Low-lever thermistor sensor is exposed when tank is empty and sends signal to FMCP
Overflow thermistor sensor senses fuel and illuminates caution light
If tank is not installed the FMCP automatically bypasses it
ALL STORES JETT inhibited with less than 40gal (272 lbs) in tank - SEL JETT must be used
|FUEL TRANSFER SYSTEM||2 pumps and 2 valves - only 1 pump and 1 valve operate at a time during Auto transfer - Both pumps and valve operate during manual transfer |
No unmonitored fuel transfer until main tank below 3200 lbs
Once Main Fuel Tank has decreased ~300 lbs, perform manual fuel transfer check.
If difference in cell quantities stop fueling prior to right cell reaching
If transfer fails PUMP/VALVE FAIL caution illuminates and opposite pump and valve is activated. It transfer continues to fail then the AUX FUEL XFER caution will illuminate indicating total failure of the system
|FUEL DUMP SYSTEM||Fuel dump can occur with FMCP switches in any position. |
Not protected by WOW switch.
To dump from external tanks switches must be set to TRANSFER and MANUAL OVRD.
Dump rate is a minimum of 800 lbs/min.
Automatically terminates at 300 lbs in a cell.
When Emergency Fuel Dump Switch is activated, both transfer/dump pumps are energized, FUEL DUMP SELECTED/IN PROGRESS advisory illuminates, and the Fuel Dump indicator on the FMCP illuminates.
|HIFR||Consists of a Wiggins quick disconnect, pressure refueling fitting, pressure refueling precheck switch (allowing high-level sensors to be checked from in the cabin), and a five element GO/NO GO canister. Go/no go canister only allows acceptable fuel to pass and when a 20 psi differential exists (due to particulate matter or water contamination), fuel flow stops.|
|ELECTRICAL SYSTEM||BATTERY: 24 Vdc NICAD|
AC GEN: 115 Vac oil-cooled 30/45 kVA 3-phase 400-hz
APU GEN: 115Vac air-cooled 35 kVA 3-phase 400-hz
CONVERTERS: 115 Vac to 28 Vdc
WOW: 94% Nr
Flight: 80% Nr
Generators reconnect at 97% Nr
EXTERNAL PWR: Includes a 4 amp CB that places a 2 amp draw on cable when connected
BATTERY < 30% may lose CADs (fire-fighting ability)
BATTERY "CHARGE LOW" caution: <40% (DC Essential Bus removed <35%)
Normal battery life (80% charge): 11 min day / 9 min night
|Functions of the GCU:|| 1. Connect generators to electrical system|
2. Regulate generator output
3. Protect from overvoltage
4. Protect from undervoltage
5. Protect from underfrequency
6. Protect against feeder faults
|If demand exceeds power available load shedding will occur:|| 1. The B/U hyd pump (#1 Pri Bus) will always be powered if required|
2. Mission systems and TR de-ice (AC Sec Bus) are the second priority
3. Lowest priority is the MR de-ice (AC Monitor Bus)
|External Power Monitored for:|| 1. Over Voltage|
2. Under Voltage
3. Over Freq.
4. Under Freq.
5. Phase Rotation
|HYDRAULIC SYSTEM||Fluid supplied at 3000 psi except to pitch and roll trim actuators (1000 psi)|
Backup Pump is powered by 3 phase AC electric motor. Internal depressurizing valve aids startup of electric motor by reducing output to 700 psi. After 4 sec on APU generator power or .5 sec with either main generator, the internal depressurizing valve closes and 3000 psi is supplied.
#1 Transfer Module contains 1st stage primary servo shutoff valve and 1st stage T/R servo shutoff valve.
#2 Transfer Module contains 2nd stage primary servo shutoff valve and pilot assist servo shutoff valve.
Utility Module routes fluid to both #1 and #2 modules, the 2nd stage T/R servo, APU accumulator, and Rescue Hoist. Velocity Fuse within module secures flow to the APU accumulator if flow rate exceeds prescribed limit.
Priority valve - Secures fluid to Rescue Hoist in a low pressure situation created by high hydraulic demand (2650psi) to ensure flight controls have enough pressure to function normally.
|BACK UP HYD SWITCH|| OFF - Remains off unless airborne (WOW switch) then acts as if in AUTO|
ON - Circulates fluid to each transfer module and maintains pressure in APU accumulator and rescue hoist systems
AUTO - Maintains pressure in #1 and #2 hyd systems and 2nd stage T/R servo as required
|Automatic backup pump operation:|| 1. #1 PUMP (light illuminates at 2000PSI)|
2. #2 PUMP (light illuminates at 2000PSI)
3. #1 RSVR LOW
4. #1 T/R SERVO
|Hydraulic Leak Test Requirements:|| 1. AC Power|
2. Backup Pump Auto
3. Reservoirs Full
5. Rotors Engaged
|AFCS SYSTEM Functions:||1. Automatic Preflight Check (SAS 1)|
a. WOW Rotor Brake ON
b. ENG TRQ < 10%
c. Both EGI attitudes valid
d. AFCC on for at least 20 seconds
2. Stability Augmentation
3. Hover Augmentation / Gust Alleviation
a. SAS 2 function that further improves stability at low airspeeds using attitude retention & long and lat acceleration
a. Auto trim from left wing down in a hover to level at 50 KIAS
5. Airspeed Hold
a. >50 KIAS & <30° AOB
b. Trim switch: 6 KIAS sec & 6° roll/sec
6. Attitude Hold
a. <50 KIAS
b. Trim switch: 5° / sec
7. Heading Hold
a. Engages (following turn): Roll attitude within 2° wings level and yaw rate < 2° / sec
b. Collective Trim switch: 3°/sec < 50 KIAS < 1°/sec
8. Turn Coordination (above 50 KIAS with >1° roll)
a. Engaged when lateral cyclic > 3%, cyclic trim pressed, or roll attitude exceeds 2.5°
9. Maneuvering Stability
a. >30° AOB
b. 1% forward cyclic for each 1.5° AOB up to 75° AOB
10. RADALT Hold
a. 0 - 5000' AGL
b. TRQ limited to 120% < 80 KIAS < 106%
11. BARALT Hold
12. Automatic Approach
a. Can be initiated from any altitude < 5000 AGL
b. A/C assumes wings level when selected and again at 80 KIAS (trimmed turn may = spiraling approach and water impact)
c. Trim switch adjusts profile airspeed ±1 kt/sec decel (2 sec input), normal profile resets by tapping TRIM REL switch or passing through 40 KGS
13. Coupled Hover
a. Trim switch: ±10 KGS
b. Manual engage < 5 KGS, Auto engage < 1 KGS
c. Radalt hold auto: within 2 feet selected altitude
d. AFCC TRQ cutoff 116%
e. Cyclic trim release resets 4 way inputs
f. Climb/Descent rates = 1000 fpm / 200 fpm
14. Crew Hover
a. ±5 KGS
15. Automatic Depart
a. Profile to 150' / 120 KIAS
b. Available when: Auto Pilot ON + <50 KIAS + RADALT
c. Passing 50 KIAS if AOB < 5° assumes a wings level attitude, if > 5° assumes a coordinated turn for set AOB
d. TRQ limited to 120% < 80 KIAS < 106%
16. Cable Angle
a. Engagement requires 27 +/- 12 ft depth (unless OVERIDE engaged), < 5 KGS, and within 10ft of selected altitude
b. Secures automatically when dome passes through 20ft depth (unless OVERIDE engaged)
c. AFCC desensitizes the cable angle signals to prevent undesired helo movement as a result of cable tension changes causing flashing CABLE ANGLE lt for 6 sec
17. Diagnostic (Fail Advisory)
18. Blade Fold Assist
19. Stabilator Control
|Stab Inputs:|| 1. Collective Position |
2. Lateral Acceleration
4. Pitch Rate
|FLIGHT CONTROL SYSTEM||The cyclic, collective, and tail rotor pedal flight controls are routed aft and outboard of each pilot seat, vertically up each side of the aircraft,|
and are combined for each axis at the overhead torque shafts inside the hydraulics bay. The overhead torque shafts
transfer inputs from the trim servos and flight controls through the pilot assist servos and the mixing unit. From the mixing unit, fore, aft, and lateral inputs are transferred to the swashplate assembly via the primary servos and the bridge assembly. The yaw inputs to the tail rotor servo are transferred from the mixing unit aft to the tail rotor quadrant through the tail rotor cables.
|TAIL ROTOR SYSTEM||Tail Rotor canted 20° to provide 2.5% lift in a hover|
6 section tail drive shaft - ballistically tolerant - suspended at 4 points by viscous-damped bearings.
Tail Rotor Servo is mechanically actuated by the tail rotor quadrant and tail rotor cables, but requires hydraulic pressure to operate the pitch change shaft, which moves the tail rotor pitch change beam, which changes pitch of the blades via the pitch change links. (Control is maintained with loss of hydraulics between approx 40 and 120 KIAS)
Two spring cylinders connected to the quadrant allow cable tension to be maintained if either cable is broken (TAIL ROTOR QUADRANT caution)
If both cables are severed, two separate centering springs will position tail rotor servo to provide a fly-home capability (19,500 lbs at 25 kts and 145 kts balance flt is maintained - below 25 and above 145, helo will yaw right)
|PYLON FLIGHT micro switches:|| 1. Pylon lockpin switch|
2. 5° switch
3. T/R blade indexer
4. Stab lockpin switches (x2)
|ECS|| Heat / AC from 2 to 71°C|
ECS Norm: TRQ avail reduced 4% & FF increased 8 lbs / hr
Temp switch HOT < 15° C max TRQ avail reduced 5%
FLOW HIGH max TRQ reduced 7% & FF increased 12 lbs / hr
|ECS Auto Shutdown:|| 1. C-pwr|
2. Starter Engaged
3. ECS Overtemp
With AIR SOURCE ECS START SWITCH = ENG
1. TGT 851° C
2. ANTI ICE SWITCH - ON
3. DEICE MSTR - ON (ICE DETECTED)
4. ECS UNDERPRESSURE
|COMM SUBSYSTEM BACKUP / FAIL MODES:||1. SINGLE FMC FAIL (AMC operational and AC avail) - No Impact|
2. FMC BACKUP MODE (AMC operational and AC available) - Enabled when AMC normal but loses 1553 data bus traffic with FMCs. ICS unchanged. AMC operates normally except all control is through the OCP and RCU. OCP selected Clear/Secure, DF and Relay not available.
3. AMC BACKUP MODE (FMCs operational and AC available) - After an AMC reset, loss of primary power to AMC, aircraft power transients, or loss of OCP. RAD 1 is hardwired to pilot station and RAD 2 to copilot station (both controlled by RCU, PTT only). ICS CALL is available to all stations.
4. BATTERY MODE (DC battery power only) - Only RAD 1 is available, hardwired to pilot station and controlled by RCU, PTT only. ICS PTT is available to the pilots, and ICS not available aft.
|FIRE DETECTION / FIRE EXTINGUISHING SYSTEM||3 Control amplifiers and 5 sensors|
Sensor sends signal to amplifier which activates appropriate lights
Eng Fire T-Handles - When pulled fuel selector is mechanically place to OFF and the logic module selects the compartment into which the Halon will discharge.
APU T-Handle - When pulled it removes power from APU fuel shutoff valve allowing it to close, removes power from prime boost pump, sends stop signal to ESU/DESU, arms the fire extinguisher system, and positions the directional control vavle to APU.
Directional Control Valve is only on the #1 side and it determines whether the #1 ENG or the APU will receive agent.
Fire-extinguisher logic module determines whether the #1 or #2 side will receive agent.
10g sensor (battery bus) - #1 side to #1 ENG and #2 side to #2 ENG
|RESCUE HOIST SYSTEM|| 0 - 215 fpm (Breeze Eastern)|
0 - 250 fpm (Lucas Western)
200 ft usable cable
First and last 20' orange
Pilot control - 100 fpm
Backup hoist ctrl - 85 fpm
Hoist speed auto 50 fpm last 10' up / 5' down (inop in bkup)
|JETTISON|| ALL STORES JETT:|
1. WOW not active
2. ALL STORES JETT button pushed
ALL STORES - Safes Weapons, Complete in 7 seconds
2. Left Inboard
3. Right Inboard
4. Left Outboard
PYLON SEL JETT:
1. Sel Jett in appropriate position
2. WOW not active
3. Master ARM armed
| ADHEELS (around the SO window and cabin door)|
45 min illumination and independent of a/c power Activation:
| 1. Fresh or saltwater immersion|
2. 11 - 13g's
3. ATT changes 100 ± 5°
| IHEELS (small strip on the window)|
| 1. Fresh or saltwater immersion|
2. Attitude changes 100 ± 5°
|ELT|| 121.5/243.0 |
Auto activate 5g impact
Detect 100 miles @ 10,000'
|Dipping Sonar (ALFS) 6 modes of operation:|| 1. Normal|
3. Aux Hydraulic
4. Aux Electric
6. Aux Hardware Electric
|The Navigation Subsystem consists of the following components:|| o Two Embedded GPS Inertial Navigation Systems (EGIs).|
o Two Air Data Computers (ADCs).
o Two Air Data Transducers.
o Two Air Speed Transducers.
o TACAN Set.
o Direction Finding Group (DFG).
o On-Top Position Indicator (OTPI).
o Radar Altimeter (RADALT).
o Automatic Flight Control System (AFCS).
|EGIs||Each EGI consists of a five channel Coarse/Acquisition (C/A) and Precise (P) code GPS receiver with full Selective Availability/Antispoofing (SA/AS) capability embedded in an all-attitude ring-laser gyro Inertial Nav Unit.|
EGI 2 is connected to a stand-alone Fixed Reception Pattern Antenna (FRPA) GPS antenna and EGI 1 is connected to a dual SATCOM/GPS antenna.
GPS Antenna System (GAS-1) is a seven-element anti-jamming Controlled Reception Pattern Antenna (CRPA) and an Antenna Electronics (AE) unit. The AE unit nulls out suspected erroneous signals and passes "good" signals to the EGI navigation system.
P-code (military) GPS accuracy requires that the EGI be keyed with the appropriate codes. Codes are loaded directly in the EGI units.
|The Course Needle (CRS) sensitivity, when slaved to TNAV, is effected by the selected mode. The two modes are:|| Enroute Mode (ENRT) - Deviations are 2 Nm/triangle or 5O/dot. Capture radius 1000 yards.|
Approach Mode (APPR) - Deviations 0.2 Nm/triangle or 1.25O/dot. Capture radius 240 yards.
|Tracking to a Waypoint/FTP can be via 4 different methods:|| 1. TO TO - Requires 2 points enroute. Guidance is reference to a direct line between the 2 points.|
2. DIRECT TO - Navigates a direct line from current position to the point.
3. CONT TO - Continuously points toward the point (like a TACAN).
4. TO FROM - Allows you to input an approach course to the point (default is the wind at time of entry)
|EGI ALIGNMENT||GPS (HNAV) Alignment - (Default Alignment Type) can be conducted while shore based (stationary) or shipboard (moving), and GPS must acquire and track at least four satellites before the alignment will begin. |
In-Flight Alignment - Same as HNAV just occurs with WOWs (airborne)
Gyro Compass (GC) Alignment - Designed to align aircraft when it is stationary. It is an INS- only alignment. Once complete the CMPL-GC will switch to HNAV with or without a GPS solution. If after 1 min GPS is not available operator will receive a GPS UNAVAILABLE alert and after 15 min the system will transition to INS.
Stored Heading (SH) Alignment - Exactly the same as GC alignment, but happens in 3 min instead of 4. 1 min after complete will switch to COMP-GC. Requires the following to be performed on shutdown prior to executing on the next startup (if all have not been completed will initiate a GC alignment):
1. Parking Brake - Set
2. Complete a GC Alignment on both EGIs
3. Perform a orderly shutdown of EGIs via CMP
Directional Gyro (DG) Alignment - Provides an INS-only solution and is considered a degraded mode of EGI operation since no valid velocities or position are determined. Provides basic attitude information and, if operator enters heading (DG HI), a reference heading. DG-LO only pitch and roll information is provided. With WOWs, IF Alignment must be commanded in order to initiate.
Data Link (DL) Alignment - Ship's heading, speed and barometric altitude are used to complete the alignment. If complete prior to takeoff, with WOWs, the system will switch to HNAV (if GPS is avail) and INS (if GPS is not available).
|Cable Reeling Machine 6 modes of operation||1. Automatic Mode (Normal Operating Mode) |
2. Manual Mode (Full capabilities and safety features)
3. Auxiliary Hydraulic
Manually controls servo valve in the event of a RMIU failure by bypassing RMIU and RMCU.
Bypasses all safety interlocks, doesn't automatically stop at trail, and doesn't auto seat and lock dome
Toggle switch on reeling machine allows for Aux Hydraulic selection
Speed is limited to 6ft/sec within 60 ft of aircraft
No Electrostatic Discharge sequence in this mode - lowering dome into the water in this mode will damage system
4. Auxiliary Electric
Reeling machine uses auxiliary motor to drive gear train in the event of a hydraulic malfunction
Has full safety features, will close array when raise is selected, will stop at trail, and will auto seat and lock transducer.
May cause problems with subsequent use if cable is raised in this mode from 100ft or deeper (result of slow speed and insufficient cable tension during raising evolution). Must retention using normal hydraulic mode before resuming dipping ops.
5. Auxiliary Hardware Electric
Same as Aux Electric, but without the safety interlocks, and auto stop at trail or auto seat and lock.
Enter into this mode via SAFETY OVERIDE switch while in Aux Electric mode
Speed will always be 6 ft/sec
6. Hand Crank Mode (for maintenance use only)
Provides operator control of unit
Displays status, faults, and speed
| OVRROT - excessive rotation of transducer|
TILT - >10.5° tilt
KITING - Cable is paying out faster than depth is increasing
CAB LIM - Cable reached paid out limit (8 wraps)
BOTTOM - Transducer is <50 ft from ocean floor
SNAG - too much cable tension
SLIP - reeling machine clutch slip