Ch 1 Systems Flashcards
Propeller Diameter
97”
wingtip width
33’5”
Elevator width
11’4”
T-6 Length
33’4”
T-6 Height
10’8”
Oil Level serviced should occur within how long of engine shutdown
30 minutes
Most accurate readings for oil level
15-20 Minutes
How many pickup elements in oil system
two, one for normal and one for inverted flight
Location of oil pumps
-one inside and one outside accessory gearbox
Oil Cooler location
lower aft cowl assembly
Oil tank is cast with______
vented into accessory gear box via __ point breather system, which includes
- compressor air inlet
- 4 point breather system
- breather valve and centrifugal breather
Engine oil pressure maybe show __ PSI even though engine shutdown
4 PSI
Oil Temp and Pressure sensed by
transducers downstream of main oil pump and signal EDM
EDM sends oil info to what
Signal Conditioning unit SCU which contains logic to illuminate CWS
SCU activates red OIL PX light when
Oil Pressure is at or below 40 psi with above idle power, or when 15 psi or below at idle power
SCU activates amber OIL PX when
oil pressure is between 15 to 40 psi at idle, 40 to 90 psi for 10 seconds above idle
when will both amber and red OIL PX go on
oil pressure remains between 15-40 psi at idle for 5 seconds or more
True of false: due to sensitivity of Oil pressure sensor a momentary amber OIL PX can illuminate during a maneuver and not indicate a malfunction
True
What helps prevent nuisance amber CWS illumination
SCU
What indicates a SCU fail
-when both Amber and Red Oil PX are illuminated on CWS but Oil read read normal on Engine/system display
OIL TRX power what and is located on what BUS?
- Oil pressure transducer and on Battery Bus
- if popped gauges will show “0”
Reduction Gearbox
- Two stage planetary reduction drive
- reduces power turbine 30,000 RPM to Prop operating range of 2000 RPM
What drive Reduction Gearbox
-hot gases impinging on the two-stage power turbine
Is there a chip detector in Reduction Gearbox
Yes, will trigger Red CHIP light
What is mounted on the top of the Reduction Gearbox? What else is mounted to the RGB?
Propeller interface unit (PIU), torque probe, permanent magnet alternator (PMA)
-the A/C compressor is mounted on the right side
Propeller
-97” aluminum, Four blade, constant speed, variable pitch, non reversing, feathering prop
Props Constant speed
-2000 RPM (100% Np)
What two things control prop angle and speed
-Power management Unit (PMU) and Propeller Interface Unit (PIU)
Engine is flat rated for 100% torque from sea level to _______’ MSL
-12,000-16,000’ on standard day
At 100% indicated torque how much power is engine producing
2900 foot-lbs of torque which equals 2750 lbs of thrust at sea level, zero airspeed
Propeller Pitch angle
- Feathered ( 86 degrees)
- Low Pitch (15 degrees)
- High pitch varies
In regards to the prop how do PMU and PIU influence it?
-PMU controls prop RPM by varying blade angle with oil pressure through the PIU. PIU increase pressure
PIU oil pathway
-oil pressure increase is transferred from PIU through a tube and stationary transfer sleeve into the hollow rotating propeller shaft
What will increasing oil pressure do to the prop?
- decrease pitch
- so decreasing oil pressure will cause prop to move to a coarse pitch
-How many overspeed governors are there?
- Two, mechanical and electronic
- Mechanical keep Np below 106%
- Electronic will maintain 100% Np
- PMU function is lost or deactivated, what prevents overspeed of Np
- Mechanical fly-weight hold oil pressure to maintain Np 100 +- 2%
- Centrifugal force, cause oil pressure dump
Methods to feather propeller
- PCL-off with PMU norm will open prop servo valve to drain
- Pulling PROP SYS CB will remove power from feather dump solenoid valve
Rapid feathering will do what
- PMU will thinks there is a sensor failure and switch to manual mode, dashes will be displayed for RPM and torque values
- PMU cycling will have no affect and dashes will remain
Engine Data manager (EDM) does?
- monitors engine operations and illuminates CWS is needed
- Also non-engine functions: fuel balancing, fuel quantity, DC Volts, DC Amps, Hydraulic PX,, Cockpit Alt, Cockpit differential
How does EDM transmit?
- Via EDM A and EDM B channels
- If one fails an EDM X will show on display with weight on wheels switch
Primary Engine Data Display (PEDD) shows what?
-Torque, Np, IOAT, N1, ITT (all processed via PMU)
Alternate Engine Data Display (AEDD) shows what?
- Alternate torque, alt N1, cockpit pressure, cockpit differential, fuel flow, fuel quantity, Raw ITT
- all but torque bypass PMU
What power PMU?
-Permanent Magnet Alternator (PMA), on RGB
PMA creates how much power?
-32 VAC, which PMU convert to DC
When does PMU switch to 28 VDC battery Bus
-when prop RPM drops below 40-50% Np or PMA fails
PMU two operational modes?
-Flight and ground modes
PMU Ground mode
Idle N1 is 60-61%
PMU flight mode
- Idle is 67% Min
- Above 10,000’ PMU raises N1 to 80% to avoid stress on prop in spins
Hot Start
-ITT exceeds 940 Celsius for 2 sec, 870 C for 4 seconds, 840 C for 19 seconds
Hung start
-N1 acceleration is to slow or gets hung up
Start Ready light
-ensure that light remains on for more than 3 seconds
Fire Warning System
-Dual sensor tubes and responder assemblies , mounted to exterior surface of engine
Fire Warning sensors contain?
- Helium gas and a hydrogen charged core
- Helium respond to overall threshold temp and hydrogen are highly localized
How is Fire System activated?
-Heating expands helium gas which pressurizes a diaphragm
Fire 1 and Fire 2 are powered by?
- 1 on battery bus
- 2 on generator bus
Firewall Shutoff Handle does?
-Mechanically closes fuel and hydraulic fluid along with bleed air flow
How much fuel does each fuel hold?
-79 Gallons or 527 lbs of JP-8 (6.7lbs/gal)
How much fuel does the collector tank?
-7 Gals or 47 lbs of JP-8
How much fuel does the T-6 hold?
- 1100lbs of JP-8 from single point refueling
- over the wing will give 100 lbs more (1200 lbs)
Fuel Auto balancing system
-maintain fuel within 20lbs
If Fuel system detects imbalance of 20lbs or more for longer than 30 seconds what happens?
- transfer valve will close motive flow line to light tank
- system will try to balance to less than 30lbs for 2 min, after which the FUEL BAL amber light will come on
Red FUEL PX light
-less than 10 psi fuel pressure in motive flow/return flow supply line
green BOOST PUMP light
- when manually selected or when fuel line is below 10 psi. Also the starter is on
- Battery Bus
Amber L FUEL LO/ R FUEL LO
-optical sensor indicates fuel below 110lbs in respective wing tank
How many fuel probes are there?
- 7 total
- 3 per tank and one in collector tank
What level do the Fuel probes read? Outer, Middle, Inner
- Outer: 445 +- 50lbs
- Middle: 308 +- 50lbs
- Innder: 20lbs
If a fuel probe fails?
-Will skip down to next working probe
What will not be available with a FP (fuel probe) Fail
auto fuel balancing
Fuel moves via
-transfer jet pumps create a low positive pressure in collector tank to pull in fuel
How much fuel is available for inverted flight
-15 seconds, weighted rod in pickup valve closes normal fuel pickup and open inverted fuel pickup