SY Flashcards
Three elements necessary for engine operation
Air, Fuel, Heat
Two major sections that make up the engine
- Gas Generation Section
- Power Turbine Section
Name the only primary component of the accessory compartment
The starter
Describe the PT6A-68 engine
reverse-flow, free-turbine turboprop engine rated to produce 1100 shaft horsepower
Name the gas generator section components
4C’s
1. Compressor inlet
2. Compressor
3. Combustion chamber
4. Compressor turbine
Name the power turbine section
- Power Turbines
- Exhaust Case
- Reduction Gearbox
- Propeller Shaft
Name the exhaust components
- Exhaust ports
- Exhaust stacks
What do the exhaust stacks do?
- turn the exhaust air from the exhaust ports 180 degrees
- provide a small amount of additional thrust
Name the ignition system components
- Ignition Exciter
- Two igniter cables
- Two igniters
What positions are the igniters installed?
4 and 9 o’clock at the combustion chamber
What provides the fuel for start?
The FMU (Fuel Management Unit)
What provides air for start?
The Starter
What provides heat for start?
The Ignition System
Name the positions of the ignition switch
- ON
- NORM
What illuminates when the igniters are activated?
Green IGN SEL annunciator
What does the PCL control?
Engine fuel flow
How are the forward and aft PCL’s connected?
A push-pull rod
How is the PCL connected to the FMU?
Mechanically and Electrically (through PMU)
Name the three labeled positions of the PCL
- MAX
- IDLE
- OFF
Primary functions of the PMU
- Keep engine and prop within operating limits
- Processes power requests
- Determines available power
- Provides linear response between IDLE and MAX
Amber PMU STATUS annunciator in flight, Master CAUTION, and aural tone
Indicates either failure of WOW switch or a WOW mismatch. PMU will not revert to ground mode after landing
Amber PMU STATUS annunciator after landing
PMU fault picked up in flight, notify MX
Red PMU FAIL annunciator, Master CAUTION and WARN, and aural tone
Non-functional PMU
PMU Power Supply
Primary - PMA (Permanent Magnet Alternator) 32 VAC which PMU converts to DC
Alternate (PMA Fail) - 28 VDC from Battery Bus
Oil System Purpose
provide a steady flow of filtered oil to the engine bearings, reduction gears, accessory drives, and propeller.
Oil Scavenge system
several pressure and scavenge pumps after the bearings gears, drives, and prop which return oil to the oil tank.
Oil Cooler
Cools scavenged oil before returning to the oil tank
Chip Detector
located in the reduction gearbox, sense metallic fragments in the oil system
Red CHIP annunciator, Master WARN, and aural tone
Chip detector has detected metal fragments
How long do you have to CHECK oil after shutdown?
15-20 minutes
How long do you have to SERVICE oil after shutdown?
30 mins
Amber OIL PX annunciator
15 and 40 psi at IDLE
40 and 90 psi for 10 seconds above IDLE
Red OIL PX annunciator
15 psi or below at IDLE
40 psi or below above IDLE
Both the Red and Amber OIL PX annunciators
(Ops Limit)
Between 15 and 40 psi at IDLE for 5 seconds or more
Describe the purpose of the propeller
To convert power into thrust
What controls Np?
The PMU and PIU (Prop Interface Unit)
What RPM is 100% Np?
2000 RPM
At what altitude is 100% torque available?
12,000-16,000 MSL
Phase Shift Torque Probe
Located on the reduction gearbox. Measures Np. Signal monitored by PMU
Mechanical Overspeed Governor Max Np
106% Np, 2120 RPM
Three Pitch Conditions
- Feathered
- High Pitch (coarse)
- Low Pitch (flat or fine)
PIU (prop interface unit) function
regulates system oil pressure to the pitch change mechanism
What does the prop do when oil pressure is lost?
Moves towards feather (wont fully feather until PCL is placed in off)
When starting the T-6A, the PCL should be
pushed forward until a green ST READY annunciator illuminates
Engine Data Manager (EDM)
computer unit located in the left avionics bay that monitors and processes engine operation data
EDM Engine Related Tasks
It drives the primary, alternate, and engine/systems displays and illuminates advisory, caution, or warning annunciators
EDM Non-Engine Related Tasks
fuel balancing, fuel quantity indications, activation of the nosewheel steering annunciator, a display of DC volts, DC amps, hydraulic pressure, cockpit pressure altitude, and cockpit pressure differential.
PEDD (Primary Engine Data Display)
Provides visual indication of primary engine data.
PEDD Display Information (5 indications)
- Torque
- ITT (Interstage Turbine Temp)
- N1 (Gas Generator Speed)
- Np (Propeller RPM)
- IOAT (Indicated Outside Ambient Temp)
Torque
Resistance to rotation by the prop. Measured by phase-shift torque probe.
ITT (Interstage Turbine Temp)
Temp between compressor turbine and the power turbine measured at the combustion chamber.
N1 (Gas Generator Speed)
The speed pf the compressor turbine. Measured by magnetic pulse sensor on the accessory gearbox.
Np (Propeller RPM)
Prop speed measured by phase shift torque probe
IOAT (Indicated Outside Air Temp)
Measured by T-1 Sensor located in the inlet plenum.
AEDD (Alternate Engine Data Display)
provides each cockpit with a backup visual indication of engine operations. Data not processed by PMU (like PEDD), except Torque.
AEDD Display Info (7 indications)
- RITT (Raw Interstage Turbine Temp)
- Torque
- N1
- Cockpit Pressure Altitude
- ΔP (Cockpit Differential Pressure)
- Fuel Flow
- Fuel quantity
Red CKPT PX annunciator, MASTER WARN, aural tone
ΔP exceeds 3.9 to 4.0 psi
Amber CKPT ALT annunciator, MASTER CAUTION, aural tone
Cockpit altitude exceeds 19,000 feet.
ESD (Engine Systems Display) Info (5 indications)
- Oil Temperature
- Oil Pressure
- Hydraulic Pressure
- DC Voltage
- DC Amperage
Oil Temperature
Measured downstream of the main oil pump by a transducer
Oil Pressure
Measured downstream of the main oil pump by a transducer
Hydraulic Pressure
Measured by a pressure sensor located on the power pack reservoir
Hydraulic Pressure Normal Operating Range
2880-3120 PSI
Fire Warning System Components
- Core Element
- Sensor Tube
- Responder Assembly
Fire Detection Core Element
Senses fires/hot gas
Fire Detector Sensor Tube
Senses average temps for overheat
Firewall Shutoff Handle shuts off supply of these 3 systems
- Hydraulics (to engine)
- Fuel (to engine)
- Bleed Air (from engine)
1 Fire Power Source
Batt Bus
2 Fire Power Source
Gen Bus
PEDD Power Source
Gen Bus
AEDD Power Source
Gen and Batt Bus (redundant)
ESD Power Source
Gen Bus
Types of Abnormal Starts
Hot, Hung, No-Start
Hot Start Indications
High/Rapidly Rising ITT
Lower N1
Lower Np
Hung Start Indications
Slow Rising ITT
Lower N1
Lower Np
No-Start Indications
No ITT
Lower N1
No Np
No Torque
Name the electrical system components
starter/generator
battery
auxiliary battery
external power receptacle
Name the two buses in the electrical system
Battery Bus (left)
Generator Bus (right)
Starter/Generator
primary aircraft power source. provides 28 VDC power and is capable of supplying 300 amps
Generator Control Unit
monitors generator and trips off-line in the event of a malfunction/located in AFT right cockpit.
Generator Control Switch Operation
magnetically held and electrically interlocked
Avionics Master Switch
Power for all avionics and radio systems in both cockpits EXCEPTIONS:
1. UHF control unit
2. UHF transceiver
Bus Tie Switch
used to tie the battery and generator buses together.
2 Positions: OPEN and NORM
Secondary Power Components
(everything but the starter/gen)
1. 24VDC Battery
2. 24 VDC Auxiliary Battery
3. External Power Receptacle
Primary Battery
provides power for engine starts and is capable of powering all electrical systems (except air conditioning, which is automatically shed)
Battery Switch Operation
magnetically held and electrically interlocked
Auxiliary Battery
powers a minimum number of aircraft systems and avionics in the event of failure of the generator and primary battery
External Power Control
External power is distributed on the battery bus, and is controlled by the battery switch (BAT) on the right forward switch panel
Individual Avionics Lighting
EFIS, RMU, AOA, GPS Panels all have their own dimmer knob
Landing Light
Left Main Gear. Will not illuminate until down and locked.
Taxi Light
Right Main Gear. Will not illuminate until down and locked.
Anti-Collision Light Flash Rate
30 times per minute, synchronous
What does mass balancing do?
Regulate control pressures, prevent control flutter, and improve control stability
What is mass balancing?
Moving the center of gravity of the control surface to its hinge line
The TAD calculates inputs to rudder trim based on these 4 parameters
- Pitch Rate
- Altitude
- Airspeed
- Engine Torque
The primary hydraulic system operates the following:
Gear and inboard gear doors, flaps, speed brake, nosewheel steering
T-6A hydraulic system operating pressure
3000 +/- 120 PSI
What are the 5 selector valves included in the selector manifold?
Landing Gear, Gear Doors, Speed Brakes, Takeoff Flaps, and Landing Flaps
Amber HYDR FL LO light comes under when
Reservoir fluid drops below 1 quart
Three circumstances in which emergency hydro is operated
Primary Hydro Failure, Engine Failure, Batt Bus Failure
4 Major Canopy Components
Frame, Forward windscreen, Front Cockpit Transparency, Rear Cockpit Transparency
Forward Transparency/Windscreen Birdstrike Rating
4lbs/270 KIAS
4 Canopy Sub-Assemblies
Hinge/strut system, Locking/Latching System, Sealing System, Canopy Fracturing System (CFS)
How many hooks hold the canopy closed?
5
How many switches illuminate the Red CANOPY light on the CWS?
Four. 3 on the hooks, 1 on the sill
What is the source of air for the canopy pressure seal?
Engine bleed air from the anti-g system
Piezoelectric crystals
used to detonate explosive chords in CFS. Do not require electricity to work
Flexible Linear Shaped Chord (FLSC)
Mounted on forward transparency for more powerful explosion (thicker transparency)
Mild Detonation Chord
Mounted on rear transparency (less powerful due to thinner transparency)
When would the Manual Override Handle be used?
When in mountainous terrain and seat pilot separationis is desired above 14,000 MSL
Powered Inertia Retraction Device (PIRD)
Properly positons shoulders for ejection.
How well the ejection seat performs depends on these 3 factors
dive angle, bank angle, sink rate
How far behind the aft seat does front seat ejection take place?
.37 seconds
What is the function of the drogue chute?
stabilize the seat and aid in deceleration
At what altitude will the seat separate and chute deploy?
14,000-16,000 MSL
When does the personal locator beacon begin transmitting?
When the survival kit separates from the seat
When does the personal locator beacon begin transmitting?
When the survival kit separates from the seat
How long does it take to deploy the SSK?
4 seconds
Primary Flight Controls
Ailerons, Rudder, Elevator
Secondary Flight Controls
- Aileron Trim
- Elevator Trim
- Rudder Trim
- Trim Aid Device (TAD)
(All electro-mechanically operated)
Which cockpit has priority for roll/pitch/yaw trim?
Rear Cockpit
What pressure does the reservoir step down piston regulate pump return pressure to?
50 PSI
What pressure doe the pressure release valve actuate?
3250-3500 PSI
What is the purpose of the hydraulic Slide Valve #1?
Isolate the hydro pressure coming from the engine driven pump once the Emergency System has been activated
3 specific scenarios where emergency extension is required
engine failure, batt bus failure and primary hydro system failure
When does the EHYD PX LO light come on?
2400 +/- 150 PSI
When will the hydraulic fuse trip on the emergency hydraulic system?
.25 GPM or about 1 pint of fluid lost
