NATOPS Flashcards
Overall Length
64’ 10”
Height
17’ 0”
Main Rotor Diameter
53’ 8”
TR Diameter
11’ 0”
Wheelbase
29’ 0”
Ground Clearance
19” (15” with MTS)
Engine Type
T700-GE-401C, front driven turboshaft
5 Sections of Engine
Inlet, Compressor, Combustor, Turbine, Exhaust
Inlet Airflow
Inlet Cowling > Swirl Vanes > IPS/Collection Scroll > Deswirl Vanes
IPS purpose
Prevents particles from entering the compressor
Compressor Section Stages
5 Stage Axial, 1 Stage centrifugal rotor/stator assembly
Engine Airflow Usage
30% Used for combustion process, remainder used for:
- Compressor Inlet Temperature (T2) air
- Compressor Discharge Pressure (P3) air
- Combustor and turbine cooling
- Engine oil seal pressurization
Ng Turbine
Drives the compressor and AGB
Np Turbine
Turns inside the Ng Turbine drive shaft, extends through the front of the engine connecting to power turbine drive shaft.
What is sensed between Np & Ng turbines?
TGT
AGB Components
Rear Face: Engine starter, HMU, IPS, ODV
Front Face: Alternator, Engine Driven fuel boost pump
Mounting Cavities: Lube/Scavenge pump, Chip detector
Face Pads: Oil cooler, fuel filter, oil filter
PCL - OFF
PAS mechanically shuts off fuel at the shutoff valve within the HMU
PCL - IDLE
HMU automatically controls start sequence fuel flow allowing the engine to achieve self containing combustion
PCL - FLY
Sets the max level of power that could be supplied, if demanded
PCL - LOCKOUT
PCL is used to manually control Np and Ng.
*TGT Limiting, Np governing, and load sharing deactivated in LOCKOUT
LDS System
Responds to the collective position to automatically control engine speed and provide required power.
Engine Driven Fuel Boost Pump
- Provides reliable suction feed from the fuel tank to engine
- Provides discharge pressure to satisfy minimum inlet pressure requirements of HMU
Engine Fuel Filter
Filters solid matter, but not water.
HMU responds to the PCL for:
- Fuel Scheduling
- Fuel Priming
- Setting engine start fuel flow with auto acceleration to ground idle
- Setting permissible Ng up to maximum
- DECU Override capability (LOCKOUT)
Ng Overspeed
Trips at 110+/- 2% Ng
HMU Provides:
- Rapid engine transient response through collective compensation
- Automatic fuel scheduling for engine start
- Ng Overspeed protection
- Flameout/Compressor stall protection
- Acceleration limiting
- Ng governing
Engine Control Quadrant Contents
2 PCLs (w/ starter button)
2 Fuel Selectors
2 Engine T-Handles
Rotor brake interlock
ODV Functions
- Provides fuel to 12 main injectors during start/operation
- Purges main fuel manifold overboard, after engine shutdown, to prevent the coking of fuel injectors
- Traps fuel upstream, so system priming is not required on next start
- Returns fuel back to the HMU if the Np overspeed is energized or if DECU Hot Start preventer is activated.
Alternator
Provides all essential engine electrical functions
Alternator Windings
Provide AC power to ignitor assembly, DECU, and Ng signal to vertical instruments
DECU receives the following inputs from the Cockpit:
- ENGINE SPD TRIM switch
- CONTGCY PWR switch
- ENG OVERSPEED TEST A and B buttons
DECU sends the following signals to the Cockpit:
- TGT
- Np
- Torque
- Contingency power
What does the DECU do?
Resets the HMU within acceptable engine limits to maintain Np governing while automatically limiting TGT
What does selecting Contingency Power switch ON do?
TGT limit is increased to 903 C, by a signal sent from the DECU.
Np Overspeed
Activated at 120% Np, when exceeded, a signal is sent from the DECU to ODV causing engine flameout
What could happen if you reset a No. 1/No.2 ENG OVSP circuit breaker in flight?
May initiate engine overspeed signal and result in engine failure
EDECU vs DECU
- TGT limiting
- Auto Contingency Rated Power
- Dual Auto Contingency
Engine Ignitor
When in NORM and either starter button depressed, Ignition system operates until starter dropout (52-65% Ng) occurs
Engine Oil System
Self contained, pressurized, recirculating dry sump system.
Engine Oil Sumps
6 main sump bearings
Thermal Lockout
Below 38 C, prevents the PDI from popping out
Engine Start options
- APU
- Crossbleed Air
- External pneumatic power
Crossbleed Start Ng requirements
Donor Engine Ng: 90-94%
Ng on receiving engine: 24% before PCL to IDLE
3 Ways to Anti-Ice Engines
- Vent bleed air into swirl vanes and IGVs
- Vent bleed air into engine inlet anti ice valve
- Continuous pump engine oil through scroll vanes
Engine Anti-Ice/Start bleed valve Open/Closed
Open: Below 90% Ng to prevent compressor stability
Closed: Above 90% Ng
Indications of Malfunctioning Anti-Ice/Start bleed valve
- ENG-ANTI ICE ON w/ Ng above 90% OR above 94% Ng when OAT is 15 degrees C or greater
- No advisory when Ng drops below 88% Ng
- No illumination when switch selected
- No rise in TGT when switch is on
Max torque available reduced with malfunctioning ENG ANTI-ICE?
Up to 18% per engine
Inlet Anti-Ice Valve operates at?
Less than 4 degrees C: Valve open INLET ANTI-ICE ON advisory when inlet temp reaches 93 degrees C
4-13 degrees C: Freon bellows control
Above 13 degrees C: Valve closes, advisory gone when cowling temp drops below 93 C
Np/Torque Sensors
Right: Torque computation and Np Overspeed
Left: Np signal to DECU and Cockpit vertical instrument
Ng Sensor
Alternator provides Ng signal to vertical instruments in the cockpit
TGT Sensors
Thermocouple harness, 7 thermocouples
Rotor Subsystems
- Main blades
- Hub
- Flight Controls
- Bifilar vibration absorber
Head Check
- Blade Lock Pins - Engaged
- Pitch Lock Pins - Retracted
- Gust Lock - Disengaged
Elastomeric bearings
Per blade, allow flap, lead, lag, and permit blade to move about its axis for pitch change
Swashplate
Outer: Stationary
Inner: Rotates, transmits flight control movement through 4 pitch control rods
Anti-Flap restraints
@ 35% Nr or greater, permit flapping or coning of the blades
Droop stops
Engagement: 70% Nr pulls out
Shutdown: 50% droops seat
Rotor Blades
Pressurized hollow spar, honeycomb core, outer skin, abrasion strips, deicing mats. 20 degree swept tips provide sound attenuation and rotor blade efficiency
Gust Lock primary purpose
Lock the rotor brake disc in an indexed position and prevent the brake disc from turning inadvertently should rotor brake hydraulic pressure bleed off while rotors are spread
MGB
Drives and supports the main rotor. Modular design, 3 degree forward tilt, pressure lubricated.
Input Module
Take power delivered by the Np turbine, change angle of drive, and transfer power to the main module and provide drive for respective Accessory Module.
Freewheeling Unit
Allows engines to be disengaged from the transmission when Nr exceeds Np (autorotation) and single engine operations
Accessory Module
Mounting and drive for AC electric generator and hydraulic pump module
Right Accessory Module
Nr sensor for vertical instruments
Left Accessory Module
Nr sensor for TDI and main transmission pressure sensors
IGB
Splash lubricated, transmits torque, reduces shaft speed, changes angle of drive
TGB
Splash lubricated, transmits torque to the TR
Main Transmission Oil system type
Wet sump, AC generators also use transmission oil for cooling
Main Transmission Oil Pressure Sensor
Located on the No. 1 Accessory module (furthest from pumps), activates caution at 14 psi
Main Transmission Oil Temperature Sensor
- Located at oil cooler input to MGB, activates caution at 117 degrees C or greater
- Chip detector for for readings to cockpit display
IGB/TGB Oil Temperature sensor
Embedded in the chip detectors, when temperature reaches 140 degrees C
Main Transmission Chip Detectors
5 total (1 in each module) using magnetic plugs to attract ferrous metal particles, fuzz burnoff, MGB has 30 second time delay
When is fuzz burnoff deactived?
When oil temperature reaches 140 degrees C
Fuel System Type
Crash worthy, suction type, self sealing breakaway valves capable of pressure, gravity, and HIFR
Fuel Selector positions
OFF/ DIRECT/ CROSSFEED
Main Fuel Tanks
2, 180 Gallon tanks.
Lower 1/3: 14.2mm
Upper 2/3: 7.62mm
Aux Tanks
Up to 2, 200 gallon (194 Usable)
Fuel Transfer Rate
350 lbs/ Minute
FUEL LOW caution
300 lbs in a single tank, 600lbs or less total, 300+/-15 lbs
Fuel dump rate
800 lbs/ minute minimum, down to 300 per side
precheck lever left in PRECHECK
Fuel will not transfer from aux tanks, attempting to transfer in this condition may cause transfer/dump pumps to lose prime.
*If holding XFR INT AUX doesnt work, AC must be pressure refueled
APU fuel consumption
150 lbs/hr
Acceptable in-flight APU usage
- EPs
- Single Engine Training
- Practice Autos
- Powering the ECS during extreme temps
What controls and monitors the APU
ESU
Primary AC Power
2, Oil cooled, 115 vAC generators driven by the accessory modules
Secondary AC power
Air cooled, 115 vAC generator driven by the APU
GCU
Connects each respective generator to ac bus system, regulates generator output, and protects components
GCU % On deck, In Flight, reconnect
On deck: Nr below 94%
In flight: Nr below 80%
Reconnect: 97% Nr or greater
5 AC Buses
- No. 1 AC Primary
- No. 2 AC Primary
- AC Essential
- AC
- AC Secondary
Major load on No. 1 AC primary bus?
Backup Hydraulic Pump (will always be powered if required)
External Power Receptacle
Located on right side, automatically disconnects when Main or APU generator brought online
5 DC Buses
- No. 1 DC Primary
- No. 2 DC Primary
- DC Essential
- Battery Bus
- Battery Utility Bus
Converters
2 Converters powered by No. 1/No. 2 AC primary buses supply 28 vDC to DC bus system
Battery
24 vDC located under copilot (Left) seat installed to start the APU, power battery utility bus, emergency DC power
Battery analyzer/conditioner
Located next to the battery, monitors for fault conditions, charge, temperature, cell conditions, and provides battery charge capability
What happens with a dual converter failure?
Both FDs and MDs are lost, If battery has >35% charge will take over
Normal Battery life
With 80% charge, 9 min night, 11 day
What function is lost with battery below 30% charge?
Battery power may not be able to activate fire extinguisher CADs
FAULT caution
Battery Overtemperature or Cell Dissimilarity exists
Hydraulic System PSI
3,000 psi with exception of the pitch and roll trim actuators (1,000 psi)
No. 1 Hydraulic system supplies:
Driven by left accessory module. First stage primary servos and First stage TR servo
No. 2 Hydraulic system supplies:
Driven by right accessory module. Second stage primary servos and Pilot assist Servos
Primary SERVO shutoff
(1st OFF/2nd OFF) SERVO switches, one on each collective secure fluid to respective servo. Electric interlock prevents dual securing/or to operating stage
Backup hydraulic pump supplies:
Driven by ac electric motor. APU Accumulator, Rescue Hoist, No.1/No.2 Backup, 2nd stage TR
LDI system
No. 1 System: Leak assumed to be in 1st Stage TR
No. 2 System: Leak assumed to be in Pilot Assist Servo
SERVO shutoff switch
Hydraulic Leak Test Criteria
- Ac power
- BACKUP HYD PMP in AUTO
- All hydraulic reservoirs full
- Weight on wheels
- Rotors engaged
Flight Controls: 3 Sections
- Mechanical Control System
- Flight control servo system
- AFCS
TR Spring cylinders
Connected to the quadrant, allow cable tension to be maintained if either tail rotor cable becomes severed.
Pilot Assist Servo assembly
Boost servos, SAS acutators, hydraulic (pitch and roll) trim actuators
*Turned on/off by SAS/BOOST pushbutton
Boost Servos
Collective, yaw, pitch reduce cockpit control forces and SAS system feedback
AFCS
Electrohydromechanical system that provides inputs to the flight control system to assist the pilot in maneuvering and handling the helicopter.
AFCS Subsystems
SAS, AFCC, Stabilator
4/2/1
SAS 1 / SAS 2 / TRIM / AUTO PLT
SAS/BOOST / CMPTR PWR Reset
Stabilator
AFCC
Commands the SAS actuators and the TRIM actuators in all 4 control channels. Inner loop (SAS) and Outer loop (Autopilot)
Primary purpose of the Stabilator
Provide angle of attack stability
What positions the stabilator?
Two electric jackscrew actuators
Stabilator travel
42 degrees trailing edge down (hover)
10 degrees trailing edge up (cruise and maneuver flight)
Inputs required to position the stabilator
Collective Position
Lateral Acceleration
Airspeed
Pitch Rate
Restriction of travel in event of stab actuator failure
If fails in full up: 30 degrees
If fails in the full down: 35 degrees
SAS
Provides increased stability by sensing acceleration rate in the pitch, roll, and yaw axes and applying proportionate control inputs to dampen out the sensed rate.
What type of systems are SAS 1 & SAS 2
Inner loop system
SAS 1 - Analog
SAS 2 - Digital
Difference between SAS 1 and SAS 2?
SAS 2 has CILA (Collective inner-loop actuator) which is required for:
- hover augmentation/gust alleviation
- turn coordination
- roll, altitude holds
- coupler functions
SAS control authority
+/- 10% control authority which each channel providing +/-5%
Trim system servos
2 Electric servos for yaw and collective
2 hydraulic servos (1,000 psi) for pitch and roll
Trim control authority
100% at a rate of 10% per second
Automatic Approach Profile
Starts @ 200 ft, 80 kts
>40 KTs : 2.5 kt Deceleration / 215 ft./min descent
<40 KTs: 1.5 kt Deceleration / 130 ft./min descent
Ends at 50 ft
Automatic Depart Profile
From a coupled hover accelerates to 120 KIAS / 150 ft (RADALT Hold is then engaged)
What authority does crew hover have?
+/- 5 KGS from LONG VEL/LAT VEL switches
Right WOW Functions
Generator Under Frequency Protection
Fuel Dump
Left WOW Functions
Hydraulic Leak Test ENG OUT Warning Automatic Backup Pump Operations Digital Clock (Flight Time) Rescue Hoist/Cargo hook CADs AFCS IFF Mode 4 Responses LOW ROTOR RPM Warning LAWS
Blade Lock Pin Purpose
Lock/Unlock the fold hinge
Pitch Lock Pin Purpose
Fix the pitch of the rotor blades to maintain clearance
Gust Lock Purpose
Lock the rotor brake disc in an indexed position and to prevent the rotor brake disc from turning inadvertently should rotor brake hydraulic fluid pressure bleed off while rotors are spread.
Automatic Preflight Checks Requirements
- Both EGI attitudes valid
- Rotor brake on
- Engine torques below 10%
- WOW
- SAS 1 Pushbutton engaged
RADALT provides precise information up to:
5,000 ft AGL and pitch and roll angles up to 45°
RADALT declutters at
1,050 ft AGL
Pitot Static system
Provides static and dynamic pressure to the FDs and AFCS via the ADT, AST, and ADCs. Also directly to the backup instruments
How many fire detectors are there/where?
5, two in each engine and 1 in the APU
How do the fire detectors work?
When a detector senses Infrared Radiation (fire) and no blue light (sunlight) it sends a signal to the associated control amplifier, activates master warning panel FIRE light, and lights associated T-Handle
What are the fire bottles filled/charged with?
Filled with Nitrogen charged with Halon
Where is the fire compartment located?
Aft of the APU compartment
What does pulling aft on an Engine T-Handle do?
Mechanically places the fuel selector OFF, logic module selects proper compartment for charge
What does pulling the APU T-Handle do?
Removes electrical power from the APU airframe, fuel shutoff valve, removes power from prime-boost pump, sends stop signal to ESU, arms system.
FIRE EXTGH switch positions
OFF, MAIN, RESERVE - Spring-loaded to off position
FIRE EXTGH - MAIN when held:
With AC power:
Forward bottle: No. 1 Engine or APU
AFT: No. 2 Engine
FIRE EXTGH - RESERVE when held:
Forward bottle: No. 2 Engine
AFT: No. 1 engine or APU
What is unique about the No. 2 Fire department
Does not work with no ac power and the RESERVE position must be used on the switch
When activating No. 1 Engine or APU handle, which one is armed if both are pulled?
The last T-Handle pulled is the system to be armed.
Fire Extinguisher Impact sensor
Activates at 10gs impact
What automatically shuts down the ECS?
- Contingency (C-Power) is selected on collective
- No. 1 or No. 2 Engine starter engaged
- An ECS heating duct overtemperature exists
When shall pitot heat be turned on?
Less than 5°C OAT or visible moisture
How many troop seats may be installed in addition to the Gunners seats?
AGS: 11
Legacy: 12
What electrical bus supplies power to the hoist?
No. 2 DC primary
DC essential for BACKUP
Hoist limit switches
50fpm at: Full Up Full down 5 from floor 10 from door
Cockpit hoist control speed
100 fpm
Backup control speed
85 fpm
Cyclic Emergency Release caution
Pressing the cyclic EMER REL with CARGO HOOK CTRL armed and RSQ HOIST PWR/ARMED will fire both CADs
ADHEELS activation
45 minute
- Water immersion
- Impact of 9gs or greater
- Attitude changes of 90° or greater
- Manual activation
IHEELS activation
20 minutes
- Water immersion
- Attitude changes of 90° or greater
Overhead rings/Deck rings
23 Deck rated at 5,000 lbs
9 Overhead rated at 3,500 lbs
JP-5
Primary
F-44
6.8 lbs/gallon
JP-8
Primary
F-34
6.7 lbs/gallon
JP-4
Restricted
F-40
6.5 lbs/gallon
Fuel mixture for shipboard hangaring
70% JP-5, 30% JP-8 or 100% JP-5 to ensure flashpoint is greater than 120° F
PRIST
Fuel system Icing Inhibitor (FSII) available premixed and discharged via aerosol can. Aerosol can is not authorized due to it settling to the bottom of the tank damaging system
Primary fuel
A fuel the aircraft is authorized to use for continuous, unrestricted operations
Restricted fuel
A fuel that imposes operational limitations to the helicopter
JP-4/JET-B operational limitations
- Single engine training prohibited
- Operating conditions may change
- Next two refuels shall be with primary fuel
Emergency fuel
A fuel which may be used for a minimum time when no other fuels are available in case of emergency or operational necessity
Fuel changeover procedure when JP-4 was in the tank
- Assume all tanks filled with 100% JP-4
- Empty Aux tanks into main tanks before refueling
- Operate in DIR only
How much fuel to be considered rid of JP-4?
Cumulative total of at least 360 gallons per tank (720 total)
What does fuel flow in PRECHECK mean?
A shutoff system malfunction, fueling shall only be continued if necessary
What is a start cycle defined as?
Starter initiation, Acceleration in Ng, and Starter dropout/disengagement.
How long between start attempts?
60 seconds minimum
APU acceptable in flight uses
- EPs
- Single Engine training
- Practice Autorotations
- Powering the ECS during extreme temperature
Autorotation maximum speed
100 KIAS
Hovering turn rate limitation
30° per second
External load rate of descent limitation
1,000 fpm
Prohibited Maneuvers
- Aerobatic Flight
- Practice Full Autos
- Intentional approaches inducing retreating blade stall
Rotor brake operating limitations
Max Nr: 76%
Routine: 30-50%
180 psi
With PCL in LOCKOUT, which functions are disabled?
TGT limiting, Np Governing, Load sharing
DECU Functions
- Np Governing
- Np Overspeed Protection
- TGT Limiting
- Engine Load Sharing
- Engine Speed Trim
- C-Power
- Np Overspeed Test
- DECU LOCKOUT
- Cockpit Signals
- Fault Diagnostic System
- Hot Start Prevention
- 400 Hz airframe power capability
- TDI
- Auto-ignition system
- Ng decay rate relight
Rescue Hoist 3 Limits
- 40 KIAS
- 30 AOB
- 20 ft above obstacles
Rotor Brake operating limits
Max: 76% Nr
Routine Stops: 30-50% Nr
Limit to 180 psi to extend service life
Max Rate of Descent (Level and Sloped)
Level: 540 fpm
Sloped: 360 fpm
Tailwheel Locked/Unlocked
Locked: 60 KGS
Unlocked: 20 KGS
Braking Speed
35 KGS
Slope Landing Limits
Up: 9°
Down: 6°
Cross: 12°
Internal Weight Limits
Max: 5,500 lbs
Palletized Cargo: 4,733 lbs
Single Pallet: 3,000 lbs
External Weight Limits
Cargo Hook: 6,000 lbs
Hoist: 600 lbs
Flight into Icing conditions
No blade de-ice: Prohibited into forecast or known icing conditions
Operable Anti-Ice: Known moderate or severe prohibited (trace/light conditions okay)
What is required for Passenger Transfer Overwater?
ADHEELS/IHEELS
Backup Pump Limitations
33°-38° C: 24 minutes (72 minute cool down)
39°-60° C: 16 minutes (48 minute cool down)
APU Operating Limits
Rotors not engaged: Continuously up to 51°C
Rotors Engaged: Continuously up to 43°C
43-60°C is limited to 30 minutes
Nontactical/FAM Flights Crew Requirements
Two H2Ps or 1 HAC and a qualified observer
FCF Crew Requirements
1 FCP and 2 qualified observers
Orientation Flights Crew Requirements
One HAC, one qualified observer, one aircrewman
Utility Mission (passenger transfer/cargo) Crew Requirements
One HAC, One PQM, One Utility Aircrewman
SAR Mission Crew Requirements
One HAC, One PQM, One MH-60S Utility Aircrewman, and One H-60 Rescue swimmer
Ferry Flight
One HAC, One PQM, one aircrewman or TFO
How many swirl vanes are there?
12
Abort start criteria
- Ng does not reach 14 psi within 6 seconds
- No oil pressure within 30 seconds
- No light-off within 30 seconds after moving PCL to IDLE
- ENG STARTER light disappears prior to 52% Ng
- TGT is likely to exceed 851 C
Aircrewman responsibilities during an emergency
- Provide pilots with necessary verbal calls to continue safety of flight
- Complete applicable CMIs
- Utilize PCL to complete non-CMIs
- Backup pilots with PCL to max extent possible
- Assist PNAC with troubleshooting
Primary purpose of the main transmission
Take power from the engines, reduce RPMs and transfer to the main rotors
Secondary function of the main transmission
Drive for electrical and hydraulic power generation
What does the main power train consist of?
Main transmission modules, tail rotor drive shafts, oil cooler, IGB, TGB
How are the generators cooled?
Transmission oil
Tair drive shaft sections, couplings, viscous dampers
6 sections, 5 Thomas couplings, 4 viscous dampers
How many chip detectors in the transmission?
7 - Main module, each input, each accessory, IGB, TGB
How many PDIs in the helicopter?
12
7 Hyds bay
2 each engine
MGB
Can you remove chip detectors without loss of oil?
Yes
What is fuzz burnoff?
Burn off false particles to prevent false indications and is deactivated when oil temperature reaches 140 C
Nr Limitations
96% - 101% : Continuous
101% - 120%: Precautionary
120% Max
Single engine TRQ Limitations
0-135 Continuous
135 - 144 (10 Sec)
144 Max
Oil Pressure Limitations
30-65
45-60 for level, continuous flight