Chapter 2 Catchall Flashcards
How many sensors are in the fire detection system? What are they?
5 sensors
2 in each engine compartment
1 in the APU compartment
What do the fire detector sensors detect?
infrared radiation, not blue light (sunlight)
In the 1 position, what does the FIRE DETR TEST check?
the continuity of the three firewall-mounted detectors (No.1 eng, No.2 eng, and APU)
In the 2 position, what does the FIRE DETR TEST check?
the continuity of the two engine deck-mounted detectors (No. 1 and No. 2 engine)
What are the two fire bottles filled and charged with?
filled with Halon, charged with nitrogen
What does pulling aft on the fire T-handle accomplish?
arms the fire extinguishing system and mechanically places the fuel selector in the OFF position
When both the No.1 engine and APU T-handles have been actuated, which compartment will the fire bottles be discharged in?
into the compartment for the T-handle that was last actuated
When both the No.1 engine and APU T-handles have been actuated, which compartment will the fire bottles be discharged in?
into the compartment for the T-handle that was last actuated
List the 5 things that happen when you pull the APU fire T-handle.
- Removes electrical power from the APU fuel shutoff valve, allowing it to close
- Removes power from the prime boost pump
- Sends a stop signal to the DESU
- Arms the fire extinguisher system
- Positions the extinguisher directional control valve to the APU
What happens when you pull aft on the No.1 or No.2 engine T-handle?
arms the fire extinguishing system and mechanically places the fuel selector in the OFF position
When AC power is not available, which compartment has no fire extinguisher capability?
the No.2 engine compartment
What crash impact forces will activate the fire bottles? And into which compartments?
a multi-axis impact of 10gs will discharge one fire bottle into each engine compartment
What are the two types of rescue hoists? What are their variable speeds?
Breeze-Eastern – 0-215fpm
Lucas-Western – 0-250fpm
What weights are the rescue hoist brake, boom, and hook rated to?
brake = 600 lbs.
boom = 1000 lbs.
hook = 3000 lbs.
How many feet of useable cable does the rescue hoist have? What is different about the first and last 20’ of cable?
the hoist contains 200’ of useable cable
the first and last 20’ are bright orange to warn of end approaching
From the cockpit, the pilots can control the rescue hoist at a fixed speed of what?
100 fpm
In backup control power, the hoist is controlled at a fixed speed of what? What do you lose in backup control?
85 fpm
the limit switches are inoperative in backup control
What function do the limit switches for the rescue hoist serve?
whenever the hoist issuing raised or lowered at a speed exceeding 50 fpm, it will automatically decelerate to 50 fpm approx. 10’ from full-up or 5’ from full-down
On the scratchpad, the burn rate in lbs./hr is an average of over how much time?
the burn rate over the last 6 minutes
Where does the IFF transponder pull current altitude from?
the backup altimeter
The SO station receives the LAWS tone based on which pilot’s DH setting?
the right seat pilot
What does the shimmy damper do?
causes both the tail gear wheels to rotate at the same rate
preventing aircraft tail oscillations during taxi, takeoff, and running landings
What may occur during a single-EGI failure in a coupled hover?
altitude changes of +/- 40’ from what is selected on the HVR ALT potentiometer may occur
ADHEELS system operation
Advanced Helicopter Emergency Egress Lighting System provides lighting to the upper half of the cabin door and SO window.
activated by crash/inversion sensor by any of the following:
- fresh or saltwater immersion
- impact force of 11-13 G’s or greater
- attitude change of 100 +/- 5 deg or greater (pitch or roll)
will remain illuminated for 45 minutes
IHEELS system operation
Individual Helicopter Emergency Egress Lighting System provides lighting of both the cabin door and SO window jettison handles.
activated by crash/inversion sensor by any of the following:
- fresh or saltwater immersion
- attitude changes of 100 +/- 5 deg or greater (pitch or roll)
How many aircrewman safety belt anchor points are located in the cabin?
5
one above the SO seat, two aft of the xmsn access cover, one above the sonobuoy launcher, and one in the tunnel
All Stores Jettison function
completed within 7 seconds
jettisons all external stores (excluding CMDS) and launches each sonobuoy in sequence (if pressurized)
HYD LEAK TEST requirements
“BRAAW”
“BRAAW”
- Backup Pump AUTO
- Rotors engaged
- AC power on
- All reservoirs fulL
- Weight on Wheels
Automatic Backup Pump ON initiated when:
[#1 HYD PUMP]
[#2 HYD PUMP]
[#1 RSVR LOW]
[#1 TAIL SERVO ON]
Name the 10 lights/cautions associated with the HYD LEAK TEST
1 RSVR LO
#2 RSVR LO
BACKUP RSVR LO
SAS
BOOST SERVO OFF
AFCS DEGRADEd
#1 TAIL RTR SERVO
#2 TAIL RTR SERVO ON
BACKUP PUMP ON
MASTER CAUTION
What type of fuel system do we have?
crashworthy, suction-type system
What portion of the main tank is self-sealing?
the lower 1/3
What is the capacity of the main tank?
590 gallons or 4,012lbs. of JP-5
What is the interconnect level for the left and right tank?
270-600lbs.
How is the fuel weighed?
each tank has a fuel probe that is a capacitance-type sensor that employs fuel as a dialectic to measure the fuel weight
What creates the required suction to draw fuel from the cells?
the engine driven boost pump
Describe the fuel flow.
main tanks – fuel selector levers – engine driven boost pump – pressure sensor – fuel filter – HMU – fuel/oil heat exchanger – ODV – engine for combustion
What are the four main functions of the ODV?
- Provides main fuel flow to the 12 fuel injectors.
- Purges fuel overboard after shutdown to prevent coking in the injectors.
- Traps fuel upstream in the fuel/oil heat exchanger so that system priming is not required prior to the next start.
- Returns fuel back to the HMU if the Np overspeed protection is energized or the EDECU hot start prevention is activated.
The external fuel tanks are ______ and _______ hardened.
crashworthy and ballistically
What is the capacity of the external fuel tank?
113 or 120 gallons
What two sensors does the external fuel tank have?
the low-level thermistor sensor and an overflow thermistor sensor if there is fuel in the external tank vent line
What is the rate at which fuel is dumped?
minimum of 800lbs/min.
How do you dump fuel from the aux tanks?
TRANSFER and MANUAL OVRD then press L / R INBD and select fuel dump
True/False: The fuel dump system is protected by weight on wheels.
FALSE.
Single-point pressure refueling has a standard psi of ____.
55psi
With power on the aircraft, what order will the tanks fill?
main, right external, left external
During gravity refueling, what order are the tanks filled?
any order
At what pressure differential will fuel flow stop during HIFR?
20psi
What will happen if your left tank vent valve is malfunctioning during HIFR?
uneven filling of the main tank may occur due to trapped air in the left fuel cell causing the fuel level to remain below the high level sensors.
the fuel flow will not be shutoff and the cell will over pressurize and possibly rupture.
If the right cell fills faster than the left, monitor and stop refueling before the right cell is full (1700lbs)
When can you initiate an unmonitored manual transfer?
3,200lbs
In order to minimize crew desensitization when fuel washes on and off the sensors, the master caution will be displayed when a fuel low condition is detected for a period greater than ________. This condition is deactivated when the condition is not detected for a period of ________.
5 seconds, 20 seconds
From which cell is fuel drawn for the APU?
the right cell
Describe the difference between [PUMP/VALVE FAIL] and [AUTO FUEL XFER FAULT].
PUMP/VALVE FAULT: single XFER/shutoff valve or XFER/dump pump fail, in which case the alternate supplies fuel
AUTO FUEL XFER FAULT: lack of fuel XFER from the aux to the mains. This may be caused by a failed closed XFER valve, both XFER/dump pumps inoperative, FMCP control failure, or blockage in the fuel lines
When should you check manual fuel transfer operation?
When the main tank has depleted 300lbs
When is ALL STORES JETT inhibited for the aux tanks?
<40 gal (272 lbs.)
Use SEL JETT when the aux tank is <300 lbs. because the aux tanks only report in 50 lb. Increments
Describe the function of the FMCP mode switch ‘AUTO’
The fuel management logic is not initiated until the main tank <2640lbs.
Describe the FMCP mode switch ‘MANUAL OVRD’
Both XFER valves are open, both XFER/dump pumps are on and external fuel is transferred to the main tanks until the high level sensor is reached or the aux tanks are empty.
The main gear box has what type of design?
a modular design with a 3 degree forward tilt
When will the chip detector/temperature sensor in the wet sump trip an [MAIN XMSN OIL HOT] advisory?
if temperature > 105C
How is the xmsn oil cooled?
via an air/oil cooler that uses a blower driven by the rotor drive shaft
What advisories/cautions will the pressure sensor in the MGB illuminate and when?
[MAIN XMSN PRESS HI] caution = psi > 130
[MAIN XMSN PRESS HI] advisory = 65-130psi on VIDS
[MAIN XMSN PRESS LO] advisory = when < or equal to 30psi with Nr > 25%
When will the [MAIN XMSN OIL HOT] caution illuminate? Where is the sensor located?
caution illuminates when temperature > 117C
located in the MGB at the air/oil cooler input to the MGB where the oil should be the coolest.
What do the input modules provide? What do they contain?
The input modules provide the first stage of gear reduction and house the freewheeling unit.
What is the purpose of the diaphragm coupling?
allows for slight angular or axial misalignment of the output shaft in the input module during normal ops.
if a whining noise occurs during rotor engagement, this could be indicative of a diaphragm coupling failure and the aircraft must be shutdown immediately.
What is the purpose of the accessory modules?
to provide mounting and drive for the AC generators and hydraulic pumps
What sensors are located on the #1 and #2 accessory modules?
Right accessory module — Nr sensor for the vertical instruments
Left accessory module — Nr sensor for TDI colocated with the main transmission low oil px sensor
Where is the [MAIN XMSN PRESS LO] caution sensor located and when will it illuminate?
in the #1 accessory module, illuminates if pressure < 14psi
When are the [IGB OIL HOT] or [TGB OIL HOT] cautions illuminated?
when temperature > 140C
What is the difference between a steady, low xmsn oil pressure vs. a continually decreasing pressure?
a steady low pressure may indicate a single pump failure in the wet sump
a decreasing pressure may indicate a leak
How many sections is the tail drive shaft and how is it suspended?
The tail drive shaft has 6 sections, is ballistically tolerant, and is suspended at 4 points by viscous-damped bearings.
What feature do the IGB, TGB, and main transmission chip detectors provide?
Burn off feature — eliminates false warnings by fuzz and minute particles. This feature is deactivated when oil > 140C because that is the oil flashpoint
Automatic Preflight Checks (requirements)
“BREWS”
on AFCS ground check we check SAS 1 for 10 seconds to ensure the rate gyros are functioning properly.
following conditions must be present (BREWS):
- both EGI attitudes valid
- rotor brake on
- engine torque < 10%
- WOW
- SAS 1 engaged
What is the primary purpose of the stab?
to provide AOA stability by maintaining a level attitude in forward flight and eliminating undesirable nose-up attitudes caused by rotor downwash at low airspeeds
Name the four control inputs required to position the stab.
“CLAP”
- Collective postion
- Lateral acceleration
- Airspeed
- Pitch rate
How many degrees is the stab limited to if it’s failed full-down? Full-up?
full-down = restricted to 35 degrees full-up = restricted to 30 degrees
The stab indicator is powered by what system? The ability to slew the stab?
stab indicator = AC powered
slew the stab = DC powered
Name the four types of mechanical compensation (control mixing) and the one type of electrical compensation.
Collective to yaw
Collective to lateral
Collective to longitudinal
Yaw to longitudinal
Collective / airspeed to yaw
Collective to yaw (control mixing)
main rotor torque causes the nose of the aircraft to yaw to the right with increased collective
to compensate, the tail rotor thrust is increased
Collective to lateral (control mixing)
the tractor tail rotor causes the helo to drift right with increased collective
to compensate, the rotor disc is tilted to the left
Collective to longitudinal (control mixing)
rotor downwash on the stabilator causes the nose to pitch up and the helo to drift aft with increased collective
to compensate, the rotor disc is tilted forward
Yaw to longitudinal (control mixing)
the tail rotors 2.5% lift factor causes the nose to pitch down and the helo to drift forward when left pedal is applied
to compensate, the rotor disc is tilted aft
Collective / airspeed to yaw (control mixing)
because the tail pylon is a vertical airfoil, the nose will tend to yaw to the left as airspeed increases which means that less anti-torque is required
the trim will compensate by washing out pedal requirements as airspeed increases
How are the cyclic, collective, and pedal flight control inputs routed to the rotor system?
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 in the hydraulics bay.
the overhead torque shafts transfer inputs through the pilot assist servos and the mixing unit.
from the mixing unit, the FAL inputs are transferred to the swashplate assembly via the primary servos and the bridge assembly.
from the swashplate, the inputs move upward through the pitch control rods to the pitch change horns
Explain the spring tension and centering spring feature in the tail rotor.
there are two spring cylinders connected to the quadrant that provide tension to the tail rotor cables.
the spring tension feature allows for a fail safe if one cable breaks whereas the centering spring allows for present spring-loaded position of the tail rotor in the event both cables fail.
either failure will trigger the [TAIL ROTOR QUADRANT] caution
Explain the fly home capability of the tail rotor system.
if both tail rotor cables fail, the fixed tail rotor setting provides a fly home capability of balanced flight to a 19,500 lb. aircraft on a standard day at sea level at 25 or 145 kts.
What type of engine do we have?
T700-GE-401C front drive turboshaft engine
What type of compressor do we have?
5-stage axial, single-stage centrifugal
What type of combustion chamber do we have? How many ignitors and fuel injectors?
flow-through annular combustion chamber with 2 igniter, 12 fuel injectors, and 1 exciter
What type of turbines do we have?
dual stage coaxial turbines (Np lives inside Ng)
Where is TGT measured?
between the Ng and Np turbines using 7 thermocouples
What does the Ng turbine drive?
the compressor and the accessory gear box
What does the Np turbine drive?
the power turbine drive shaft
The power turbine drive shaft extends through the front of the engine and connects to the high speed shaft which connects to the input modules
Explain the breakdown of airflow in the engine. (Think %)
30% of the total airflow through the engine is used for combustion
70% is used for: compressor inlet air temperature (T2) compressor discharge air pressure (P3) combustion and turbine cooling engine oil seal pressurization
Name the functions of the HMU. (RANFAN)
- R - rapid engine transient response through collective compensation. (LDS)
- A - automatic fuel scheduling for engine start (PAS)
- N - Ng overspeed protection (110+/-2%)
- F - flameout and compressor stall protection (variable geometry vane)
- A - acceleration limiting
- N - Ng governing (T2, P3, Ng to sked fuel flow)
What does the variable geometry vane servo do?
using fuel tapped from the HMU, the servo opens the anti-ice / start bleed valve preventing compressor instability
the valve opens at 88% Ng and closes at 90% or 94% with OAT > 15C
What is the relationship between the torque motor servo and the metering valve?
the metering valve schedules engine fuel flow commensurate to the current power demand
the torque motor servo trims fuel flow by the the metering valve in response to the EDECU
What does the linear variable displacement transducer (LVDT) do?
provides a feedback signal to the EDECU to null the torque motor servo input therefore stabilizing the metering valve and preventing engine oscillation/hunting
What does EDECU stand for?
enhanced digital electronic control unit
Np overspeed protection
when Np > 120%, a signal is sent from EDECU to ODV, diverting fuel to the inlet of the HMU therefore causing a flameout
Contingency power: Manual, Auto, Dual-Eng
Manual - switch allows TGT up to 903C, max contingency range power limiter will prevent further fuel flow at 891+/-10C
Automatic - enabled in OEI conditions when torque of one engine < 50%, TGT limit reset from 866+/-10C to 891+/-10C (light will not illuminate)
Dual-engine auto - TGT up to 891+/-10C if the following exists: 1) Np < 96% 2) >3% droop between reference and actual Np 3) >5%/sec. Np droop with Np < Np reference
TGT limiting
fuel flow stopped at 866+/-10C so that TGT does not exceed 878C.
Np/Nr will droop and Ng governing will be sacrificed to protect against an overtemp.
EDECU lockout (what do you lose and retain?)
Np and Ng with PAS and LDS positions only, torque motor servo is disabled (loss of TGT limiting, Np governing, and load sharing)
Np overspeed protection retained
Name the four main functions of the ODV.
“Provides, Purges, Traps, Returns”
- Provides main fuel flow to the 12 fuel injectors during engine start and operation.
- Purges the main fuel manifold overboard, after engine shutdown, to prevent coking of the fuel injectors.
- Traps fuel upstream, which keeps the fuel/oil heat exchanger full, so that system priming is not required prior to the next start.
- Returns fuel back to the HMU if the Np overspeed is energized or if the EDECU hot start preventer is activated.
What are the three ways to anti-ice the engine?
- vent 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 engine inlet anti-ice valve
- continuously pump engine oil through the scroll vanes
What type of valves are used for anti-ice operation?
solenoid-operated air valves
they are held closed electrically. de-energized the valves are opened
What does the engine anti-ice / start bleed valve do?
provides 5th stage bleed air to the engine swirl vanes and inlet guide vanes with anti-ice selected ON and opens during engine starts
When does the engine anti-ice / start bleed valve open during starts? When does it close?
the valve remains open below 80.5% Ng to prevent compressor instability during starts
above 96.5% Ng, the valve closes, unless anti-ice is selected on, or the aircraft experiences a loss of electrical power
the range of acceptable Ng speeds at which the valve opens and closes is depended on OAT
Name the three indications of a malfunctioning anti-ice start / bleed valve.
- Appearance or disappearance of the ENG ANTI-ICE ON advisory when outside of the range specified in the chart in Chapter 22.
- No illumination of [ENG ANTI-ICE ON] advisory when ENG ANTI-ICE switch is ON.
- No rise in TGT when ENG ANTI-ICE switch is selected ON.
What is the indication of a malfunctioning engine inlet anti-ice valve?
[INLET ANTI-ICE ON] advisory when OAT > 13C
the resultant loss of torque could be a maximum of 49% when the anti-ice valves are open.
What is the difference between main and tail rotor de-icing?
the main rotor blades are de-iced in cycles and the rotor blades are de-iced simultaneously
main rotor blades are de-iced in cycles to reduce power requirements, to de-ice in cycles the main rotor blades have a blade de-ice distributor
Describe the operation of the Freon bellows.
- <4C, valve open [INTEL ANTI-ICE ON] appears when inlet temp = 93C
- 4-13C, valve is variably open based on OAT
- > 13C, valve closed [INTEL ANTI-ICE ON] extinguishes when inlet cowling temp <93C
Where is the inlet anti-ice valve located?
the engine inlet cowling
If the DE-ICE MASTER switch is ON, what controls the engine anti-ice/start bleed and inlet anti-ice valve?
the ice detector
The DE-ICE MASTER switch position controls what function?
ON = the automatic functionality of the ENG ANTI-ICE, WINDSHIELD ANTI-ICE, and BLADE DE-ICE POWER systems when ice accumulation sensed by ice detector
OFF = automatic function disabled
ON + ENG ANTI-ICE, WINDSHIELD ANTI-ICE, and/or BLADE DE-ICE POWER = auto function disabled and appropriate system will operate continuously
How does the ice detector sense ice accumulation? How can you determine the severity of icing?
ice detector, mounted on No.2 engine cowling, senses ice accumulation on a vibrating probe by measuring the change in probe frequency.
simultaneously, an aspirator heater on the probe is turned on to heat the probe, and shed the accumulated ice, resetting it for another cycle.
the severity of icing environment is proportional to the rate at which the probe heater is cycled.
When should the Blade De-Ice MANUAL (T, L, M) mode be used?
when [ICE DETECT FAIL] illuminates or when there is no indication of failure but one of the three following conditions exist:
- the pilot has determined by judgement of icing intensity that the ice rate system is inaccurate
- torque required has increased to an unacceptable level
- helicopter vibration has increased to an unacceptable level
When is pitot heat required?
pitot heat shall be turned on when OAT is 5*C and below or when visible moisture is present.
WARNING: Failure to turn on pitot heat in icing conditions may cause erroneous airspeed indications, which can lead to erratic and/or downward programming of the stabilator and loss of control of the aircraft.
When are anti-ice/de-ice systems required?
shall be turned on prior to entering visible moisture (including clouds) at ambient temperatures of 5*C or less.
An additional torque increase up to ______% per engine may be experienced due to ice buildup during normal operation of the blade de-ice system.
14%
Ice accumulation resulting in a ______% torque increase indicates that normal autorotational rotor rpm may not be attainable should a dual engine failure occur.
20%
Where is the engine anti-ice/start bleed valve located?
in the inlet particle separator (IPS)
Explain the airflow through the engine.
Ambient air > Inlet cowling
- Inlet anti-ice valve provides anti-ice capability, inlet fairing also perforated to heat with 5th stage bleed air
Inlet cowling > Inlet Particle Separator (IPS)
- Swirl Vanes impart rotation, particles thrown outward to collection scroll
- Hollow to allow 5th stage bleed air from engine anti-ice start bleed valve
- Blower Assembly dumps dirty air from collection scroll overboard
- Deswirl Vanes remove rotation from clean air and provide smooth air to compressor
IPS > Compressor
- 5 stage axial, single stage centrifugal rotor/stator assembly
Compressor > Combustion
- Flow-thru annular combustion chamber
- 2 ignitors, 12 fuel injectors
Combustion > Dual-Stage Coaxial Turbines
- Ng Turbine drives compressor and AGB
- Np Turbine turns inside Ng turbine and drives power turbine drive shaft which extends thru the front of the engine and connects to high speed shaft which connects to the input module.
APU fuel consumption rate
150 lbs/hr.
AC Electrical Bus Load Shedding priority
- Backup Hydraulic Pump - #1 AC PRI
- Mission Power + T/R De-Ice - AC SEC
- M/R De-Ice - AC Monitor
GCU underfrequency protection
GCU disconnects AC Generators when:
- WOW, Nr < 94%
- In flight, Nr < 80%
Minimum Nr to reconnect Gens is 97%
With one AC generator and the APU, which pigs can be powered?
pick 2/3
- Backup pump - #1 AC Pri
- Mission Power + T/R De-ice - AC Sec
- M/R De-ice - AC Monitor
With only one AC generator online and no APU, which pigs can be powered?
either the #1 AC PRI or AC SEC (backup pump or mission power)
AC monitor bus is dropped (m/r de-ice)
With only the APU online, which pigs can be powered?
only the #1 AC Primary Bus (backup pump)
Explain the engine start sequence.
- Starter button pressed
- AIR SOURCE ECS/START switch routes air from APU through the engine anti-ice start bleed valve to the engine starter
- Engine starter turns compressor blades which turns Ng turbine
- Ng powers AGB which drives engine driven alternator and senses rise in Ng
- Engine anti-ice start bleed valve stays open to reduce back pressure and prevent compressor instability until Ng reaches OAT variable range
- Engine driven alternator supplies AC power to ignitor exciters
- ENG IGNITION switch NORM gives ignitors spark
- Fuel automatically scheduled via HMU
- PCL moved to IDLE
- HMU shutoff valve opens and allows fuel to flow to ODV
- ODV routes fuel to 12 fuel injectors
- Ignitors continue until starter dropout occurs (52-65% Ng)
How many logic modules does the LDI have and where do they receive inputs from?
The LDI incorporates two logic modules that receive inputs from the hydraulic system automatic low-level sensing and pressure switches and command actuation of the hydraulic system shutoff valves.
Explain the LDI flow in the #1 HYD system.
First indications:
- [#1 RSVR LOW]
- [#1 TAIL RTR SERVO]
- [#2 TAIL RTR SERVO ON]
- [BACKUP PUMP ON]
LDI tests if leak is in the #1 TAIL SERVO. If the leak stops, leak is in #1 TAIL SERVO. No.1 HYD pump supplies the No.1 primary servos and Backup Pump supplies #2 TAIL SERVO.
If leak does not stop, [#1 HYD PUMP] appears, tail rotor servo advisory and cautions disappear.
PILOT ACTION NOW REQUIRED
Pilot action – servo switch 1st OFF
- Lose No.1 primary servos
- Backup pump supplies #1 TAIL SERVO
- [#1 HYD PUMP] [#1 PRI SERVO PRESS] [#1 RSVR LOW] [BACKUP PUMP ON]
No Pilot action
Leak stops
- Upstream of transfer mod
- Backup pump supplies entire No.1 system
- [#1 RSVR LOW] [#1 HYD PUMP] [BACKUP PUMP ON]
Leak continues
- Leak in No.1 primary servos
- [BACKUP RSVR LOW] until complete loss of backup hydraulic fluid resulting in loss of entire No.1 system
- [#1 HYD PUMP] [#1 RSVR LOW] [#1 PRI SERVO PRESS] [#1 TAIL RTR SERVO], no more [BACKUP PUMP ON]
Explain the LDI flow in the #2 HYD system.
First indications:
- [#2 RSVR LOW]
- [BOOST SERVO OFF]
- [SAS]
- [AFCS DEGRADED]
LDI tests if the leak is in the pilot assist servos. If the leak stops, leak in pilot assist. No.2 HYD pump supplies primary servos, pilot assist servo functions lost.
If leak does not stop, [#2 HYD PUMP] and [BACKUP PUMP ON] appear, pilot assist servo cautions disappear.
PILOT ACTION NOW REQUIRED
Pilot action – servo switch 2nd OFF
- Lose No.2 primary servos
- Backup pump supplies pilot assist servos
- [#2 HYD PUMP] [#2 RSVR LOW] [#2 PRI SERVO PRESS] [BACKUP PUMP ON]
No pilot action
Leak stops
- Upstream of transfer mod
- Backup pump supplies entire No.2 system
- [#2 RSVR LOW] [#2 HYD PUMP]
Leak continues
- Leak in No.2 primary servos
- [BACKUP RSVR LOW] until complete loss of backup hydraulic fluid resulting in loss of entire No.2 system
- [#2 HYD PUMP] [#2 RSVR LOW] [#2 PRI SERVO PRESS] [SAS] [BOOST SERVO OFF] [AFCS DEGRADED], no more [BACKUP PUMP ON]
How do you know if you have a CEDECU vs. an EDECU?
Software configuration is indicated 30 seconds after airframe power is applied in the form of a unique torque code, which is visible for 20 seconds.
For the Navy T700-GE-401C, a torque code of 35 +/- 2.9% is displayed for the CEDECU.
A display of 0% is not valid for CEDECU and indicates presence of an EDECU.
How do you suppress and recall EDECU fault codes? How do you clear them?
- Suppressed and recalled by pressing either one of the ENG OVSP TEST buttons
- Codes are cleared using the EDECU fault code clearing procedure in the PCL
- Cleared fault codes are verified by stabilizing TGT above 425C with PCL in IDLE or FLY and then performing a normal shutdown
What is the purpose of the droop stops and flap restraints? When do they come out and seat?
- Droop stops and flap restraints prevent extremely high or low blade flapping at low Nr.
- When Nr is 35%, anti flapping restraints are pull outwards by centrifugal force and permit lapping and coning of the blades.
- Droops out by 70% Nr and seated by 50% Nr.
