NATOPS Flashcards
Primary Fuels
A fuel that the aircraft is authorized to use for continuous unrestricted operations.
JP-5, JP-8, F-24, and TS-1
DLQ Currency
Difference Between EGI 1 and EGI 2
EGI 2 provides pitch/roll/heading synchro data; along with attitude, heading, and velocity validity signals (heading and velocity data required for automatic approach)
EGI 1 only provides pitch/roll synchro data and attitude validity signals
EGI 2 is connected to GAS-1 and the FRPA (fixed reception pattern antenna), in case GAS-1 fails, through the data transfer interface unit
Loss of Tail Rotor Effectiveness
Inability of the tail rotor to provide sufficient force to maintain yaw controllability. Function of rotor rpm and tail rotor angle of attack.
Where to check for ice in subfreezing temperatures (precheck)
Fuel drains
Engine inlets
Rotor head and blades. tail rotor, flight controls
Fuel tank vents
Engine oil tank vents
Transmission vents
Battery vent
Pitot-static tubes and ports
Turbulent Air Penetration
Moderate Turbulence = limit airspeed to blade stall minus 15kts
Light Turbulence = limit airspeed to blade stall minus 10kts
Dual Concurrence Call Items
PCLs
T-Handles
Fuel Selectors
Generators
Computer PWR Switches
EGI PWR Switches
Saltwater Power Deteroriation
TGT rise of 20* or more for constant torque = engine performance degradation and possible salt encrustation
TGT rise of 40* or more for a constant torque = may result in compressor stalls
Check windshield wipers. If you need to use them, engines are intaking a lot of saltwater. Take a lap out of the hover and drive clean air through the engines to assist with this situation.
Rollovers
Static rollover angle: 28* (will roll if tipped to this degree)
Critical rollover angle: 12* (maximum lateral slope that can be negotiated in a takeoff or landing)
Limiting vs. Limited
Limiting = Components trying to protect themselves, or physical limitations of the system. Automatic functions of the system. (ie. TGT limiting = begins to restrict fuel flow to prevent overtemp of the engine)
Limited = Chapter 4 limitations to prevent damage, extend life of components, etc. Manual functions of the pilot. (ie. Torque limited = pilot can continue to sit in the precautionary range, and the system will not stop them)
Types of LTE
AOA Reduction: winds 060-090*
Weather Vaning: winds 120-240*
Tail Rotor Vortex Ring State: winds 210-330*
Main Rotor Disc Vortex Interaction: winds 280-330*
Recovery:
- Lower collective to decrease torque and right yaw tendency
- Forward cyclic to increase airspeed, and if necessary, turn in direction of rotation.
- At very low speeds or hover, full left may arrest right yaw.
Instrument Takeoff
- Hover mode.
- Increase collective and maintain hover attitude, allow AFCS to maintain heading.
- Increase to climbout power. Passing through 20ft, push cyclic 5* nose down.
- Cross check instruments for acceleration and climb (500fpm)
Vortex Ring State
Measurable at descent rates greater than 700fpm and airspeeds between 0 - 20kias.
Worst at 1,500fpm and airspeeds between 5 - 10kias
May be encountered to quick stops or autorotations.
Recovery:
- Decrease collective pitch.
- Increase forward airspeed.
- Enter autorotation if altitude permits.
Types of Main Transmission Malfunctions
- Chip
Consider reducing load on module by putting PCL in IDLE for Input Chip or taking a generator down for Accessory Chip
- Lubrication
Steady, low pressure indicates a single pump failure.
Continually decreasing pressure indicates a leak. A complete loss of lubrication may result in tail rotor drive failure in as little as 8 minutes.
Precheck valves
Flow of fuel when precheck valve is in PRECHECK position indicates a shutoff system malfunction. As long as one precheck valve is operative, the aircraft can be refueled safely. If neither precheck valve will secure fuel flow, fueling should be continued only if necessary. If fueling is required, proceed with caution in order to prevent rupture of the main fuel tank.
Autorotation
Descent velocities between 3,125 and 4,450fpm at 19,000lbs gross weight.
Rotor Disk Lift Ratios:
Prop- 30% (Usable lift)
Auto- 45% (Forward tilting force that creates both lift and pro-rotational force)
Stall- 25% (Drag)
Slow response in an auto can lead to Nr decay to unrecoverable levels in 2 seconds.
Comm Subsystem Backup Modes
- Single mission computer failure: no affect on ICS or radios
- 1553 databus failure: no affect on ICS and radios must be tuned via OCP/RCU
- AMC or OCP failure: ICS call available to all stations and radios are hardwired to pilot seats (1 - Pilot / 2 - Copilot)
- Battery mode: ICS PTT for pilots, ICS for aft stations and radio 1 is hardwired to pilot seat
Secondary Missions
Amphibious Warfare
Air Warfare
Health Services
Fleet Support
Intelligence Operations
Logistics Operations
Naval Special Warfare
Primary Missions
SUW
ASW
EW
Command and Control
Non Combat Operations
Humidity and Density Altitude
10% increase in Humidity = 100ft of Density Altitude 100% humidity = +1,000ft DA
ECS TRQ and Fuel Consumption
ECS HOT = -5% TRQ per engine and +45lbs/hour each engine
ECS NORM = -4% TRQ per engine and +8lbs/hr each engine
ECS HIGH = -7% TRQ per engine and +45lbs/hr
Four Things Requiring Operational Necessity
- Night Vertrep
- Night HIFR
- Emergency Fuel
- Landing via one or two wheels
Types of High Side Failures
HMU: engine signals still remain valid
EDECU: erroneous engine signals, use Ng to diagnose because it is a signal that doesn’t come from the EDECU
Minimum Flight Crew Requirements
Non-tactical/familiarization flights= Two H2Ps, or one HAC and qualified observer
Functional check flights= One FCP, one qualified observer, and one aircrewman
Orientation flights= One HAC, one qualified observer, and one aircrewman
Utility missions (PAX, cargo, etc.) One HAC, one PQM, and one aircrewman
SAR missions= One HAC, one PQM, one MH-60R crewman, and one H60 search and rescue aircrewman
SUW/ASW missions= One HAC, one ATO, and one Sensor Operator
Gravity Refueling with engines or APU operating
Gravity fueling is not authorized with engines or APU operating. In addition to the hazard caused by the location of the tank openings relative to the engine exhaust, the rotors constantly build up a static electrical charge of 15,000 to 20,000 volts, creating an extremely dangerous spark potential.
Fuel Servicing Warning about flameouts
Flameouts may be encountered following nosedown ground operations in excess of 10 minutes when using JP-5, JP-8, or equivalent fuels
Torque increase due to icing
Increase up to 14% each engine may be experienced due to ice buildup during normal operation of the blade de-ice system
Warning: Ice accumulation resulting a 20% torque increase indicates that normal autorotational rotor rpm may not be attainable should dual-engine failure occur
If JP-4/JET B is used, the following operation restrictions/considerations apply:
- All takeoffs shall stabilize in a hover with no fuel pressure cautions for aminimum of 10 seconds before commencing transition to forward flight
- Single-engine training is prohibited
- Operating characteristics may change. Lower operating temperatures, slower acceleration, and shorter range may be experienced.
- Due to vapor qualities of mixed JP-4/JET B, the next two refuelings with a primary fuel shall be treated as JP-4/JET B is in the tanks
Restricted Fuels
A fuel that imposes operational restrictions on the aircraft.
JET A1, JET A, JP-4, and JET B
AFCS Automatic Preflight Checks
- Weight on wheels
- Rotor brake on
- Engine torques below 10%
- Both EGI attitude valid
- SAS1 pushbutton engaged (after AFCC on for at least 20seconds)
Emergency Fuels
A fuel which may be used for a minimum time when no other primary or restricted fuel is available in case of emergency or operational necessity.
JP-800+100 AND F-27
Loss of Tail Rotor Authority
Power issue. High gross weight and/or DA. In extreme cases, main rotor speed will droop, leading to torque increase while power to the rotors decreasing rapidly. Eventually tail rotor will be unable to produce enough thrust and helicopter will SPIN TO THE RIGHT.
Unusual Attitude
Pitch >30* and Roll >60*
Three Steps for Every Sonar Malfunction
- Alert Crew
- Execute Reeling Machine Malfunction emergency procedure
- Complete Sonar Troubleshooting checklist
What is the purpose of the Rear View Mirrors?
The mirror permits the pilot to
observe recovery/docking and hoist operations and the copilot to observe sonobuoy deployment.
Ch.7 note about STAB check
Helicopter shall not be flown if the stab fails an check involving manual operation, position indications, or warnings.
During Stab checks (Ch. 7) If Stab auto mode fails, what can you try to do
If auto mode fails to engage, slewing stab full up then full down with ac power on may align the stab actuators and allow auto mode to engage.
When in our checklists will we able to notice an LDS roll pin malfunction?
- Ng isn’t matched within 3% with PCLs in idle.
- Engine with failed LDS roll pin will indicate higher Tq which advancing to FLY from IDLE (good engine might not indicate Tq at all until in FLY)
Which way will the aircraft yaw during the cushion of an actual auto? and why?
left yaw, which is the opposite of practice autos because with practice autos you have power on and you are applying power to the aircraft which means right yaw.
Rate of decent during an auto (heavier v. lighter)
A heavy helo has a slower rate of decent because slightly more collective is required to control Nr, providing a little more lift and therefore a slower decent.
Control Mixing
How does AVCS work?
10 accelerometers sense the vibes from the rotors then 5 force generators input a 4P vibe force to null those vibes
Why do we shutdown AVCS on deck?
AVCS continuously analyzes vibes and resets the solution on a 5 minute cycle and leaving it on may result in erroneous vibes being put into the solution.
3 ways to anti-ice the engine
- bleed air into the engine swirl vanes and Inlet Guide Vanes by the Engine Anti-Ice/Start bleed valve
- Vent bleed air into the airframe engine inlet by the inlet anti-ice valve
- Continuously pump engine oil through the scroll vanes.
Letter of Promulgation
The NATOPS Program is a positive approach toward improving combat readiness and achieving a substantial reduction in the aircraft mishap rate.
Nomenclature for our Engines
T700-GE-401C
When does the Engine Anti-Ice/Start Bleed Valve close
above 90% Ng
Identify a malfunctioning anti ice/start bleed valve
- advisory on above 90% Ng or 94% Ng if temp above 15C
- no advisory when Ng dropbs below 88% Ng (sliding scale based on OAT)
- no illumination when you turn it on
- no rise in TGT when you turn it on
Inlet anti-ice operation
- less than 4C = full open
- between 4-13C = variable
- above 13C = full closed
TGT bias from the EDECU
-71C, so when the ENG OVSP cb is pulled, TGT will indicate 71C higher
How is TGT sensed?
7 thermocouples measure TGT and display the average. Sensed between the gas generator (Ng) and the power turbine (Np)
Purpose of the gust lock
To index the rotors during blade fold and prevent the rotor brake disc from turning if hydraulic pressure bleeds off while the rotors are spread.
C: hold the switch for 5 seconds when using it to not get a partially engaged gust lock without an associated advisory
Auto C-PWR numbers
OEI: Tq from one ENG less than 50% raises to 891 +/- 10
Dual engine:
- Np less than 96%
- greater than 3% droop between reference Np and actual Np
- greater than 5%/sec Np droop when Np is less than or equal to reference Np
When do the generators turn off?
- with WOW, if Nr drops below 94%
- in flight, underfrequency protection is disabled, remain online until Nr drops below 80%
- a minimum of 97% Nr is required for the GCU to reconnect the generators to the ac distribution system
When would you ever see TGT above 903 C, and why?
When in DECU LOCKOUT, because TGT limiting would keep TGT from ever getting that high.
Why does Engine Anti-Ice need to be on during a practice auto?
a malfunctioning anti-ice/start bleed valve may cause engine flameouts during flight when the collective is full down (quick stops, practice autos).
Mechanical flight control routing
Aft, out, and up, combined for each axis at the overhead torque shafts. The overhead torque shafts transfer inputs from trim and the flight controls through the pilot assist servos and then the mixing unit. From there they are transferred to the swashplate assembly via the primary servos.
How long will the battery last? And at what percent charge?
11 minutes during the day, 9 minutes at night. At an 80% charge.
At what percent charge will the battery be disconnected from this BUS?
35%
The DC ESSENTIAL BUS
Below (blank) percent charge on the battery, you may not be able to (blank)?
30%
Activate the fire extinguisher CADs
When does the BATTERY LOW CHARGE caution appear
below 40%
What mixture of JP-5 to JP-8 is acceptable for hangaring an aircraft?
70% JP-5, 30% JP-8. This ensures the flashpoint of the fuel is above 120 F
JP-5 Flashpoint
140 F
When to check Engine Oil level after shutdown
wait at least 20 minutes to prevent potential engine seal failure during the next start
When to use the HOT or COLD scale when checking transmission oil level?
HOT = between 30 minutes and 2 hours after shutdown
COLD = after 2 hours past shutdown
How long after APU Shutdown to check oil level?
1 hour
How long is cable angle hover decoupled from the AFCS when raising/lowering the dome?
9 seconds
What are the four crew configurations?
SUW
ASW
LOG/VERTREP
SAR/MEDEVAC
VERTREP power margin in NATOPS.
6% Tq
A power margin is defined as power available minus power required. Power available is defined as a continuous transmission Tq limit or TGT limit with C-power on
What makes the new EGIs different?
24 channel acquisition and SAASM, which means they have direct Y-code acquisition. Y and P codes require keys to be loaded. P-codes (precise) are better.
What drives the Alternator? What do you lose if it has failed?
It is driven by the engines. It supplies AC power to the ignitor assembly, EDECU, and the Ng vertical instrument signal.
When is the aircraft considered to be “in ground effect”
At or below 45 feet
Speed for translational lift
17-30 Knots. After this, the helo outruns its ground vortex and less power is required to create lift
What percentage of lift does the tail rotor supply in a hover? Why?
2.5%
Having lift aft of the center of gravity helps lower nose attitude in a hover.
What are the two gauges when pre flighting the rotor head?
Accumulator pressure = minimum 1200psi but temp dependent
Accumulator fluid level = in the green or yellow (full)
Servicing scenario: If on the white line between green and yellow, good to go. If on the white line between green and red, have maintenance service it. If Mx says its good like that, have them do it anyway, you’re the HAC, the AMs aren’t the ones who are going to die if a damper fails, you are. Talk to MO if you get pushback.
Tail Rotor Spar Loading
Left turns increase transient Tq. Aggressive left turns (above 30 degrees/sec and above 75 KIAS) combined with tail rotor flapping loads can cause excessive tail rotor spar loading.
When executing high roll rate maneuvers to the left, collective should be lowered with maneuver initiation to reduce tail rotor spar loads.
Rolling Pulllouts
Arresting a high rate of decent with cyclic and then turning at the same time. This changes the lift vector and can create a situation where power required for recovery exceeds power available. This creates a “Mushing” effect and the helo will continue to descend rapidly and you are going to die because you are stupid.
Types of tail rotor malfunctions and associated airspeeds
- Cable Failures. 25 KIAS and 145 KIAS at 19.5k gives you straight and level (fly home capability.
- Servo Failures. Normal yaw between 40 and 120 KIAS. Run it on above 40 so you keep tail rotor control.
- Restricted flight controls. Stuck high power = hover landing. Stuck low power = running landing.
