DA-42 Electrical/Avionics Flashcards
Describe the KAP140 autopilot system
- rate based digital autopilot system
- roll axis - wing leveler, heading select, VOR/LOC intercept and tracking, can be CPLD to GPS/RNAV
- Pitch axis - vertical speed, glideslope and altitude hold, optional altitude preselect.
- operates independent of the aircraft’s artificial horizon. Therefore, the autopilot retains roll stabilization and all vertical modes in the event of AHRS failure.
you’ve pulled the C/B to the KAP140, can you couple it once you switchi it back to on?
No, If power to the autopilot is cycled in
flight (i.e. through the autopilot circuit
breaker for instance) it is possible
that a 5 minute delay may be necessary
prior to autopilot engagement to
allow the pitch axis accelerometer
circuit to stabilize. Engagement prior
to stabilization may result in mildly
erratic pitch axis behavior
Can you use the V/S mode all the time on the KAP140
No, at or near Vy, continued climb reduces RoC, so you can decelerate and stall
what is connected to the LH MAIN BUS?
- COM1 COM Radio No. 1
- GPS/NAV1 Global Positioning System and NAV Receiver No. 1
- XPDR Transponder
- ENG INST Engine Instruments
- PITOT Pitot Heating System
- XFR PUMP/DE-ICE Fuel Transfer Pump / De-Icing System
- TAXI/MAP/ACL Taxi-, Map-, Anti Collision Light
- FLOOD/OXY Flood Light / Oxygen System
- PFD Primary Flight Display
- ADC Air Data Computer
- AHRS Attitude Heading Reference System
- GEAR WRN/ELEV. LIMIT Landing Gear Annunciation / Variable Elevator Stop
- GEAR Landing Gear Control
What is connected to the RH MAIN BUS?
- MFD Multi Function Display
- AH Artificial Horizon
- STALL WRN Stall Warning System
- FLAP Flap System
- LDG LT/START Landing Light / Start
- INST LT/ NAV LT Instrument-, Navigation (Position) Light
- AV/CDU/FAN Avionic-, CDU-Cooling Fans
- AVIONIC BUS Avionic Bus
- AV CONT. Avionic Control
What is connected to the AVIONICS BUS?
- COM2 COM Radio No. 2
- GPS/NAV2 Global Positioning System and NAV Receiver No. 2
- AUDIO Audio Panel
- AUTO PILOT Auto Pilot System
- Wx 500 Stormscope
- ADF Automatic Direction Finder
- DME Distance Measuring Equipment
- Wx RDR Weather Radar
- TAS Traffic Advisory System
- DATA LINK GDL 69A Data Link System
What is connected to the LH ENG ECU BUS? (same for RH)
- LH ECU Bus
- LH ECU B
- LH ECU A
What is connected to the LH BUS? (same for RH)
- LH Alternator
- BATT Battery
Which GPS constellation can the G1000 use?
Only NAVSTAR GPS
Can you use the G1000 for RNAV?
The system meets the accuracy requirements of EASA AMC 20-4
for Basic RNAV.
Describe the power generation system on the DA42
- by two 60 Ampère alternators (generators) which are mounted on the bottom left side of each engine. The alternators are driven by a flat belt.
- The power output line of the left hand alternator is connected to the LH MAIN BUS via the LH alternator relay and a 70 Ampère circuit breaker. The power output line of the RH alternator is connected to the RH MAIN BUS via the RH alternator relay and a 70 Ampère circuit breaker. Both main busses are connected to the BATTERY BUS via a 90 Ampère circuit breaker.
- Current sensor for each alternator
- alternator control unit. It measures the alternator output voltage
and controls the current through the alternator field coils - Load balancing: The alternator control unit supports load balancing across the two alternators via the internal alternator temperature
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Describe the electrical storage system on the DA42
- Main battery power is stored in a 24 V, 10 Ah lead-acid battery mounted on the right-aft side of the front baggage compartment
- a non-rechargeable dry battery - attitude gyro (artificial horizon) and the flood light
- ECU Backup battery L
- ECU Backup battery R - These batteries are able to provide 30 minutes of engine operation in case of a complete airplane electrical failure. Both engines may stop if the 30 minutes have elapsed.
- Excitation battery L
-
Excitaion battery R - of a main
battery failure the field of each alternator is energized by two 12 V, 1.3 Ah sealed lead acid batteries (excitation battery) connected in series, which are installed in the nose baggage compartment.
- Alternative power source: one 10 Ah 24v DC Main Battery.
- A pair of 1.3 Ah 12V DC Excitation Batteries supply excitation power to alternators in the event of failure of the Main Battery.
- A pair of 1.3 Ah 12V DC Backup Batteries supply power to each ECU bus in the event of total electrical failure.
- A non rechargeable dry cell battery provides emergency power to the standby attitude indicator.
Describe the buses on the Da42? How many in total
7
What’s connected to the Hot battery bus?
the pilot map/reading light
What’s connected to the Battery bus?
- LH/RH main bus
- LH/RH starter heavy duty power
- LH/RH ECU bus (via diode)
Describe the antennas on the DA42TDI
What are the limitations of engaging the KAP140 ON?
- successful system pre-take-off check.
- cabin window is open.
- asymmetric operation.
- CWS while manoeuvring
- significantly out of trim.
- electric trim malfunction.
- instrument approaches only when Approach Mode is selected and flaps are selected to APP or UP.
- outside the speed range of 90 to 185 KIAS.
The autopilot must be disengaged:
- Below 200 ft AGL within certain limiting speeds.
- Below 800 ft AGL for all other phases of flight.
- Below 200 ft AGL during approach operations with speed 130 KIAS or less.
- Below 250 ft AGL during approach operations with speed > 130 KIAS
- Below 200 ft AGL during departure.
- Below 800 ft AGL for all other phases of flight.
- During take-off and landing.
Auto-coupled approaches:
- The autopilot is approved for CAT 1 operation only when Approach Mode is selected and only whilst the flaps are selected to UP or APP.
Describe the electrical system on the DA42
