Auxillary Systems Flashcards
APU
How we start the aircraft and get our heat in the cockpit, as well as power on the ground. Electrical power in flight for emergencies
Doors up top between exhaust cover the APU.
Check for accumulator at 2800psi
Static rotors - APU can run at 51* maximum free air temp continuous
Dynamic rotors - APU can run at 43* max free air temp continuous
Two types, operate in the same manner, no special treatment needed by pilots
Consumes approx 120lbs per hour when running
*Contains 3 quarts of oil and has a magnetic drain plug, oil temp switch, and drain plug. DO NOT USE SIGHT GLASS TO CHECK OIL LEVEL, use the dipstick. Has a hot and cold side dipstick
APU generator - air cooled, 20/23.8KVA with a 5 minute peak transient of 30KVA for 5 minutes at 115/200VAC
Can supply total electrical power except it cannot power both the backup hydraulic pump AND windshield anti-ice at the same time (pump takes priority)
Oil hot caution requires a 30 minute cooling period. PILOT is the only person who can turn the APU off in this condition, in case the aircraft is running SOLELY on APU GEN. Turn it off, wait 30 minutes, heck the oil.
DESU controls the APU GEN, and the only condition it wont shut the GEN off automatically is the oil hot caution.
If APU fails, note and check the BITE indications before cycling battery (reset) switch or attempting another APU start.
Emergency override, flip the switch 5 times in 5 seconds and leave it in on position to start.
APU hydraulic system - accumulator provides the hydraulic pressure for driving the APU hydraulic fluid starter.
If APU does not start but the APU ACCUM LOW advisory does not come on, the manual override lever on the accumulator manifold should be pulled and another start attempted.
APU accumulator pressure gauge located in the upper aft section of the cabin. Has a pump handle that can pump the pressure to 2800psi. When ac power applied, the backup hydraulic pump will will recharge the accumulator within **90sec
APU on/off switch
Bleed air from an engine can also start another engine (takes a lot of power away) although starting the APU and doing so would allow you to keep your power.
APU T-handle (CHECK THAT IT IS PUSHED IN)- turns off fuel to the APU, sends a stop signal to the ESU and arms the fire extinguisher. (APU FIRE light indicates an APU fire…)
APU GEN ON light ONLY comes on if both main generators are off.
- *APU FIRE
- APU Fire T-handle - Pull
- Fire extinguisher switch - MAIN/Reserve as required
Backup pump comes on **4 seconds after APU powered on… like a clutch! Lets the electric motor get up to speed… do not engage the backup pump until after 4 seconds of APU start
APU fuel switch is a dummy switch. APU boost gives a boost of fuel to APU, APU prime side primes the main engine’s fuel lines
*APU purpose - provide pneumatic air source and electrical power source
Primary function of ESU for automatic starting and continuous operational monitoring
Heating and ventilation
For pilots and crew
Defogs gunner window, heats crew chief and gunner, and two pilots. ANNOUNCE when you’re turning it on (to let them put visors down)
Heated air is mixed with outside air.
Ground - can get it from the APU bleed air
Air - can get it from the engines (5% power reduction)
- Regulation valve is part of the mixing valve assembly, regulates bleed air and the mixing valve assembly mixes the hot air without outside air to achieve desired temperature selected at cockpit heating control)
- Muffler is the big fiberglass “no step” extension that guides airflow
- thermal protection switch shuts off the heat at 96*F, will come back on when it goes below that.
Fire protection and extinguishing (engines(APU))
2 engine compartment cannot fight a fire without AC aircraft power
Flame detectors
- 3 wall mounted (engines, APU)
- 2 deck mounted (engines
Trust but verify
*Solid-state Photoconductive cells sense an *IR source and will light up the FIRE light on the. MASTER WARNING PANEL, and on appropriate T-Handles (NO AUDIBLE TONE)
Fire extinguisher bottles look like a bowling ball, green lines are extinguisher lines, RESERVE is the bottle that can operate on Battery power, the MAIN uses A/C power.
Bottles have a temp/pressure chart and a safety valve will blow if pressure gets too high and blow the contents out the A/C
Pulling T-handle pulls the fuel off automatically, find a place to do a run-on since you have one engine running.
Crash actuated system - with over 10g input, both fire bottles will blow into the engine bays
Windshield wipers
Large wipers, cheap motors
Only works up to 120kts airspeed
Wiper control knob is knurled, turn to high first and then low if you need to. Then go to park first when done, then off
Do not operate windshield when dry
Rain repellent will work to repel rain at 50kts and greater
Windshield anti-ice
Want to turn it on prior to icing conditions
Electrically anti-iced and defogged; transparent conductors provide heat when electrical power is applied.
Temp of each panel is controlled to reach about 43C; fault monitoring SHOULD prevent burnout of the system by turning off the anti-ice at 43C (109*F)
Continued use of faulty windshield could result in structural damage (delamination/cracking)
Windshield anti-ice has 3 switches for each windshield
Cargo hook system
Max is 9000lbs, Max 30* cone angle
Call off EACH step in the call off so you dont blow the emergency release
Three modes of release - normal, manual, emergency
Pitot-static system
Heated pitot tubes with static system inside as well
Provides signals to barometric altimeter, airspeed, and vertical speed instruments.
Turning on PITOT HEAT will not turn on lights
Houses multiple tubes inside; two static tubes, pitot tube, and electrical connector
Static pressure is sent to the ADC’s (AIR DATA COMPUTERS)
Electronic Standby Instrument System (ESIS)
Only comes on and works when everything else fails
Gives
- pitch
- roll
- altitude
- airspeed
- vertical speed (8-12 second lag)
Components
- display
- **magnetometer
- **air data computer (ADC) - above the #2 ADC, its own ADC
- battery - in the nose (standalone system); up to 30 minutes of ESIS time
Beeping tone ONE THE GROUND is heard when the switch is left in the ARM position and no AC power is on in the aircraft.
OFF/TEST/ARM - test first, ARM before takeoff (only turns battery power on when AC power is lost)
BFGoodrich makes it
If something breaks in the ESIS during the test, it will stop at the broken portion and not continue
Whatever is broken will be red X’d in flight, but the rest will work (only really need it when you cannot see outside)
DG means free heading
IVHMS
- Integrated vehicle health management system: 150+ screens on the MFDs, 29 accelerometers (**measures high frequency vibrations); consists of the on board system, IVHMS, ground station and software. To access, B3 on MFD, then B4.
- underwater acoustic device
- cockpit voice recorder CVR
- flight data recorder FDR
- health and usage monitoring system HUMS
(Red wire and box is IVHMS)
Records at 40MB/hr
PCMCIA card is the only way to transfer data to the ground station
IVHMS data to MFD for following capabilities
- rotor track and balance
- engine monitoring
- gearbox/drivetrain monitoring
- maintenance info/diagnostics
- exceedance monitoring
- admin data
Cockpit voice/flight recorder (CVR/FDR)
- records up to 24 hours of voice and flight data
- can record a minimum of 350 flight parameters
DCUs manage recording
- *START recording criteria: DCUs monitor inputs and provide an open circuit to the CVR/FDR when ANY of the following conditions exist
- # 1 engine ON (NG > 55%)
- # 2 engine ON (NG > 55%)
- main xmsn OP greater than 20psi
- WOW switch = false
- *STOP recording criteria: the DCU’s monitor inputs and provide a ground to the CVR/FDR when ALL of the following conditions exist
- # 1 engine off (NG < 55%)
- # 2 engine off
- main xmsn OP less than 20psi
- WOW switch = true
HUMS - Health monitoring
- rotor track/balance
- engine vibration
- mechanical diagnostics (**automatic, prompted, and forced modes*)
- bearing monitoring
HUMS-E(event) switch records 15 seconds of data and voice before and after the button press, as well as 5 seconds of rotor track and balance data
Aircraft vibration control system (AVCS)!!
Reduces helo cockpit and cabin vibration mechanically by 3 force generators that input their own frequencies
90-105 NR
No more “ride-the-shutter” vibrations
it takes 2 mechanical units to make 1 force generator
Run off of AC power
Main 1000lb #1 force generator on right cabin side, #2 in the nose, #3 on the copilot crew side Which are 450lb force gens
Uses 10 accelerometers to detect and counteract vibration
Uses counter rotating weights to create counter vibes
NR speed sensor
Active vibration control computer
AVCS INOP means a total failure of AVCS system
