Systems - DA42 NG Flashcards
1
Q
Give a brief overview of the Landing Gear System
A
Acronym: THERN
T - Tricycle
H - Hydraulically actuated
E - Electronicaly powered (power pack)
R - Retractable
N - Nose gear stearing
2
Q
What is the Power Pack, what are its main components, & where is it located?
A
Acronym: REEP
1) Provides the power & hydraulic fluid for the landing gear
2)
R - Resevoir (hydraulic)
E - Electric Motor
E - Emergency Accumulator (emergency gear down)
P - Pumps for Hydraulic fluid
3) Located behind the R rear pax seat
3
Q
What are the 10 components of the Landing Gear?
A
Acronym: DUST FT PSHD
D - Down Lock Hook (DLH)
U - Unlocking Rod
S - Strut
T - Tension Spring
F - Folding Stay
T - Trailing Link
P - Position Limit Switches
S - Squat Switches
H - Hydraulic Actuator
D - Dampner
4
Q
Describe the basic overveiw of the Prop System
A
- The master switch turns on the Unfeathering accumulator & the Feathering valve. (SEE DIAGRAM)
- Main Components
* Master switch
* Solenoid valve
* Unfeathering accumulator
* GB
* Feathering Valve
* Prop Gob
* Hub
* Counterweight Latching system
5
Q
Describe the Automatic Feathering System
A
Automatic Feathering occurs when
1. Engine Master is turned off ABOVE 1,300 RPM
2. Complete loss of oil pressure
6
Q
What is the Centrifugal Latching Mechanism?
A
Weights attached to the Propeller that are..
1. Latched below 1,300 RPM to prevent unwanted feathering on the ground
2. Unlatched above 1,300 RPM to allow the prop to be feathered
7
Q
Why dont we want the prop to be feathered on the ground below 1,300 RPM?
A
- A feathered (high/coarse pitch) prop will put more stress on the engine
- The prop will produce more thrust at a lower RPM in the unfeathered (low/fine pitch) position, which is good for taxiing.
8
Q
What is meant by a Fully Feathered or Unfeathered Prop?
A
Fethering refers to the change in pitch of the propeller blade
Fully Feathered = High pitch, Coarse Pitch (low RPM)
Unfeathered = Low pitch, Fine Pitch (high RPM)
9
Q
Describe how oil pressure effects the pitch & RPM of the prop in a Twin
A
- High Oil Pressure = Low Pitch = High RPM
- Low Oil Pressure = High Pitch = Low RPM
This is the reverse of the DA40 NG.
10
Q
Describe what the Unfeathering Accumulator does
A
- Stores Compressed Nitrogen Oil (125 PSI) in order to forcibly UNFEATHER the prop to RESTART a failed engine
- Helps to maintain Oil Pressure for 5-10 seconds if lost intermittently
- The Unfeathering Accumulator is engaged when the Engine Master Switch is turned on
Essentially, the Accumulator provides Hydraulic pressure when the engine is restarted or during a temporary loss of oil pressure
11
Q
Why does the oil pressure in the prop governor of a twin work the opposite of a single engine aircraft?
A
Because if our engine fails in the twin, we want our propeller to fail in the HIGH pitch position (coarse, low RPM) in order to minimize drag
- In the single engine, we want our engine to fail in the low pitch position (fine, high RPM) in order to maximize thrust.
12
Q
What provides the oil pressure necessary to operate teh Prop Governor?
A
The Gearbox Oil Pump
13
Q
What is the Low Pitch Limit (Unfeathered)?
A
13 degrees
14
Q
What is the High Pitch Limit of the Prop (Fully Feathered)
A
80 degrees
- Close to 90, to minimize drag
15
Q
What does the Left Gear Squat Switch do?
A
A sensor that..
1. Prevents gear retraction on the ground
16
Q
What does the Right Gear Squat Switch do?
A
Acronym: G-TEST
A sensor that..
G - Glow Plugs, prevents them from being activated in the air
T - Traffic Avoidance System, turns it off on the ground
E - ECU test, prevents it from occuring in the air
S - Stall Heat, prevents it from being turned on too long on the ground (will damage it)
T - Tach time, tracks it (air time)
17
Q
How does a Squat Switch work?
A
They are essentially electrical weight sensing devices
* When weight is applied to the Landing Gear an electrical circuit is completed
18
Q
Where are the Squat Switches located?
A
On the L & R main gear
* Little black things
(see photo)
19
Q
Auxiliary fuel tank capacities
A
13.7 Max (x2: 27.4)
13.2 Usable (x2: 26.4)
We don’t use our auxillary tanks on training flights
20
Q
Main Tank Capacities
A
26 max (x2: 52)
25 Usable (x2: 50)
21
Q
What is the total fuel capacity per side?
A
39.7 Max
38.2 Usable
*including Aux tank
22
Q
What is the total fuel capacity?
A
79.4 Max
76.4 Usable
*including Aux tanks
23
Q
What is the max fuel imbalance (between the mains) when NOT using the AUX tanks?
A
5 Gal
24
Q
What is the max fuel capacity in the main tanks only?
A
52 gal total (26 per side)
50 usuable (25 per side)
25
What is the max imbalance when USING the Aux Tank?
1 Gallon
26
What are the engine restart limitations?
Above 10,000ft MSL
* IMMEDIATE Restart
Below 10,000ft MSL
* Above -5c = 10 mins
* -5c to -15c = 5 mins
* Below -15c = 2 mins
27
Which engine powers the Defrost?
Left Engine
28
Which engine powers the Cabin Heat?
Right Engine
29
What are the Operating Maneuvering Speeds? (Vo)
Up to 3,748 lbs = 112 kts
3,748 lbs to 3,968 lbs = 119
Above 3,968 = 122
30
Max T/O Weight
4,407 lbs
31
Max Zero Fuel Weight
4,045 lbs
32
Max Landing Weight
4,407 lbs
33
Minimum Flight Weight
3,197 lbs
34
Wingspan
44.5 ft
35
Where is the ELT Antenna located?
First antenna on top of the fuselage
36
Where are the Landing and Taxi lights located?
Under the fuselage
37
On the lower nose section near the OAT sensor, what is the small tube for?
Its a battery vent & TKS fluid vent/overfill drain
38
How do you know which planes will have the Short Baggage extension vs the standard?
The planes with the Short Baggage Extension will be the planes with A/C.
39
Weight limits for the planes with the Standard Baggage Compartment (short extension)
Standard Baggage Area (Arm: 143.7)
* 66 lbs (includes the Tray)
Short Baggage Ext (Arm: 156.3)
* 33 lbs
| Planes with A/C are configured this way
40
What are the weight limits for the planes with the Cabin Baggage Compartment? (long extension)
Cabin Baggage (Arm: 153.1)
* 100 lbs (inlcudes the Tray)
Baggage Ext (Arm: 178.7)
* 40 lbs
**Total not to exceed 100 lbs**
| Planes without A/C are configured this way
41
How is what is Engine Load?
A calculation from the ECU based on..
* Fuel Pressure
* Fuel Injection timing
* Manifold Pressure
* Prop RPM
42
What is the maximum steering angle using only the nose wheel?
30 degrees
| You will use breaking and thrust to turn more
43
nose wheel centering mechanism
44
Describe the Flaps on the DA42
Two main sections
* Inboard
* Outboard
Type
* Inboard are Split Flaps
* Outboard are Plain Flaps
Operation
* Electrically actuated, mechanically interconnected
45
What is the up limit of the Variable Elevator Stop and why?
13 degrees (when both engines above 20% power.
Reason: Full elevator deflection durring a stall, the stall charactoristics of the aircraft are degraded
## Footnote
If this function is not working you will see a 'STOP LIMIT' Caution on the G1000
46
How do you check the Variable Elevator Stop during preflight?
1. Hold the stick all the way aft
2. Throttle full
3. Check stop limit engagment
4. Throttle Idle
5. Check for stop limit disengagement
47
Describe how the prop will unfeather
1. The Unfeathering Accumulator will unfeather the prop when the engine master is turned on
2. Oil pressure will begin building when the starter is cranked
48
What are the approved engine shut down demonstration altitudes?
Between 3,000ft AGL & 10,000ft PA
49
Are we allowed to demonstrate a windmill restart?
No, per the AFM. We can only restart the engine with the starter
## Footnote
A windmill restart is when you start the engine using the windmilling propeller to create enough motion to engage the engine mechanisms vs using the starter moter to turn the prop/engine
50
Max restart altitude:
IMMEDIATE restarts only between 10,000ft & 15,000ft PA
51
What is the speed limit for a Starter assisted engine restart?
Max 100kts
* OR, airspeed that the prop stops spinning, whichever is lower
| AFM page 2-11
52
What is the airspeed range for restarting an engine with a Windmilling Prop?
125-145
## Footnote
This higher airspeed helps spin the prop acting as a makeshift 'starter'
53
What are the Engine Starter Motor use limitations when restarting an engine in flight?
1. Max time: 5 seconds
2. Requires a 30 second cooldown
3. Max Attemps: 3
54
Describe what each of the air inlets on the engine are for
Vew: Facing the nose cone
1.RH opening: Engine air, Intercooler air
2.Underside opening, Gearbox cooling, Radiator cooling, Fuel cooling, & Cabin Heat exchanger
3. Rear opening: air escape for all engine inlets
55
What is the temperature at which the Thermostatic Valve will open the Radiator circuit?
88c
56
Which engines operate the Cabin Defrost and Cabin Heat respectively?
LH Engine
* Cabin Defrost
RH Engine
* Cabin Heat
57
Describe the Fuel System
58
When the Fuel Valve is set to Crossfeed, what happens to the Return Fuel, which tank does it Return to?
The fuel will return to the tank it came from.
So the opposite engine will be feeding entirely off of the opposite side main tank completely independent of its own main tank.
59
Where does the RACC gets its power from?
A 3rd alternator located on the left engine
60
61
What is the RACC?
Recirculating Air Cabin Cooling
62
Explain the Limitations and Performance Impacts of the RACC
Limitations (no use)
* Above 10,000ft PA
* Below 10c
* Durring Emergencies or Abnormal Operations
* T/O, LDG, & Go-Arounds
Performance Impacts
* Adds 150lbs
* ON: -75 FPM climb, -5% TAS
* OFF: -2% TAS
63
Autopilot Max & Min operating speeds
Max 180 kts
Min: 90 kts
64
What is the ESP System?
Electronic Stability Protection system
* It increases servo forces on the control stick to keep the aircraft inside the normal flight envelope
* It is only active above 200ft AGL
65
When will the ESP system engage & disengage?
**Nose Up:**
* 16 degrees engaged
* 12 degrees disengaged
**Nose Down:**
* 22 degrees engage
* 17 degrees disengage
**Bank:**
* 45 degrees engage
* 75 degrees disengage
* Will roll the aircraft back to 30 degrees
**Vne**
* Exceeding will cause the ESP to pitch the nose up to slow down
| Source: ERAU Multi Engine Guide DA42-VI
66
How can you override the ESP system?
With either the CWS button or the AP Disconnect button
67
What is the ESP system called that crontrols our elevator pitch?
Variable Elevator Backstop
68
What bus is the TKS fluid pump on?
LH Main Bus
69
What bus are the AUX Transfer pumps on?
LH Main Bus
70
What is the minimum operating temperature of the Ice Protection System (IPS)?
-30c
| Source: AFM Supplement
71
What does the Alt Switch on the IPS panel do?
Connects the Main Pump 2 to the RH Main Bus
| It is normally connected to the LH Main bus
72
How many pumps does the Ice Protection System (IPS) have?
4 Pumps
* 2 Prop & Airfram (Main Pumps
* 2 Windshield pumps
73
Vo Weights & Speeds
Below 3748 lbs = 112 kts
Between 3748 & 3968 lbs = 119 kts
Above 3968 lb = 122 kts
74
What is TKS fluid made of?
Water-Glycol mix
75
How much does TKS fluid weigh per Liter?
2.43 lbs
76
What is the amount of TKS fluid in Liters for: Max, Usable and, Minimum Dispatch
Max: 31.5L
Usable: 30L
Disp: 22L
77
With the IPS set to Normal, how long will the TKS fluid last if full?
2.5 hours
## Footnote
Important to note for cross country flights as our full fuel endurance will be for much longer
78
With the IPS panel set to High, how long will our TKS fluid last us?
1 hour
79
With the IPS Panel set to Max, how long will our TKS fluid last?
30 mins
80
Which IPS Panel lights will illuminate when set to, Normal, High, & Max?
Normal: White light
High: One Amber light
Max: Two Amber lights
81
How will the IPS pumps behave when set to Normal?
* Both Main Pumps on
* On for 30s, off for 90
82
How will the IPS Pumps Behave when set to High?
* Only one selected Main Pump is on
* On Continuously
83
How will the IPS pumps behave when set to Max?
Both Main Pumps will run continuously but only for 2 mins
| You'll have to repeatedly press the max button after the 2 mins expires
84
How long will the Windshield panel button activate TKS fluid for when pressed?
5 seconds
85
What is the minimum amount of TKS fluid we are allowed to dispatch a flight with?
22L
86
Is the DA42 certified for Flight into Known Icing (FIKI) conditions?
Yes
87
What is one very important caveat when considering using the DA42 in Known Icing Conditions?
Per the Ice Protection System supplement: The ice protection system is not a "de-icing" system in the usual sense it can remove only small accumulations of ice. Its main purpose is **to PREVENT the accretion of ice**
| First page of the IPS supplement
88
What warning does the DA42 AFM Supplment offer about ice accumulation?
if accumulation of 1/4 inch or more on the porous panels of the TKS system is encountered you should...
* set the Ice Protection System to High/Max and..
* Leave the area of icing immediately
89
What are the limitations associated with the Ice Protection System?
Autopilot
* AP use is prohibited when icing forms behind the protected area or unusual elevator trim conditions.
Cruise & Descent speeds in icing conditions
* Min = 118 kts
* Max = 156 kts
Climbing in icing conditions:
* 118 kts flaps UP
* 90 kts flaps APP
Icing conditions
* Freezing Rain & Drizzle operations are prohibited
Temperature
* Min -30c
Configuration: Icing Conditions
* Flaps & Gear: Use only for landing
* Flaps LDG use is prohibited in icing conditions or with residual ice on unprotected surfaces
* NO OEI operations
Equipment Required
* Icing light must be operational for flight at night
90
How much time does the Min Dispatch TKS fluid amount (22L) give us when set to Normal?
90 min
91
What should you do if the IPS fails while in Icing Conditions?
1. Leave the area of Icing
2. Maintain 118 to 156 kts
3. Set power to Max Continuous to maintain airspeed as necessary
4. Nearest suitable airport
5. Land faster than normal (roughly 90kts), use of LDG Flaps is prohibited
92
What does the IPS AFM Supplement say about identifying possible freezing rain/drizzle conditions?
1. Visible rain at temps below +5c
2. Droplets that splatter on impact at +5c
3. Larger than normal performance loss than in normally encountered icing conditions
93
How do you preflight the IPS?
1. Check fluid quantity
2. Press windshield button and check for fluid dispersal, set to HIGH and check wings
3. Annunciation Test Button - Press for DEICE LVL LO & DEICE PRES LO annunciation
4. Select pump 1 and set panel to HIGH, veryify DEICE PRES LO annunciation not active. SET BACK TO PUMP 2.
5. Check Ice light
94
How much fluid is left when the DEICE LVL LO caution appears when the panel is set to Normal & High?
Normal = 45 Mins
High = 22 Mins
95
What is the maximum demonstrated crosswind in the DA42?
1. 25 kts Flaps UP
2. 20 kts Flaps APP or in Icing
96
What are the two main components of the IPS and their associated pumps?
1. Airframe & Propeller: Pump 1 AND 2 (when set to Normal/Max)
2. Windsheild: Pump 1 OR Pump 2
97
What are the approved types of TKS fluid for the DA42?
1. AL-5
2. Aeroshell Compound 07
98
What are the different Supplemental Type Certificates (STCs) that the DA42 has?
Our Aircraft:
* Vortex Generators STC
## Footnote
May exist on other DA42s:
* G1000 STC
* AmSafe Inflatable Restraint System STC
* & more
99
How many Vortex Generators may be missing OR damaged according the the STC?
Up to 5 vortex generators may be missing or damaged before the aircraft would be considered not airworthy
100
How many batteries does the DA42 have, also, what are the Volts & Amps of all our battieries & Alternators
7 batteries:
1. Main battery (24v 13.6A)
2. RH ECU A Backup battery (12V 7.2A )
3. RH ECU B Backup battery (12V 7.2A)
4. LH ECU A Backup battery (12V 7.2A)
5. LH ECU B Backup battery (12V 7.2A)
8. Emergency battery (30v)
7. ELT battery (6v)
Alternators
* 28v 70 Amp
101
What are the different ADs on the DA42
5 Total ADs
1. AD 2021-22-03 Nose/Tail Landing Gear Attach Section
2. AD 2024-06-13 T bolt replacement/ torque seal
3. AD 2024-19-10 Piston borescope inspection
4. AD 2020-14-07 Fuel Injector Replacment
5.
102
What is the pitch of the propeller when it is in its Min & Max pitch?
Max pitch: 80 degrees
Min pitch: 13 degrees
103
When are the landing gear actuators NOT under pressure?
When the Emergency Extend lever has been used
104
What is the purpose of the Landing Gear Tension Spring?
To help hold the gear in the extended position
105
What is the AFM approved altitude range for *intentional* engine shutdown?
106
At what angle are the flaps at when APP or LDG is selected?
APP = 20 degrees
LDG = 42 degrees
107
What is different about the tires on the 42 vs the 40?
The DA42 tire has an innertube
108
What is the difference between Volts & Amps hours?
1. Volts can be thought of as Power Supply
2. Amps hours can be thought of as Power Draw
109
Is the Gear hydraulic system a unidirectioinal system or an omnidirectional sytem
It is a unidirectional system, meaning that the hydraulic fluid only flows in one direction relative to the resevoir
110
To what side is the piston inside the Gear actuator deflected when retracted & extended?
Retracted = Pushed to the left (longer)
Exteded = PUshed to the right (shorter)
111
How have we estimated how much each chamber in the main tanks hold?
Based on the behavrio of the fuel quantity indicators
* only the inner and outer tank chambers have fuel quantity indicators
* Full fuel indication is 25 gallons
* Once it reads 22 gals the indicator jumps down to 17 gals and stays there for awhile, hinting that the middle tank has 5 gals. It has no fuel indicator probe
* At a certain point the fuel indication will begin to drop below 17 gals hinting that the middle tank is now empty.
112
How does the hydraulic fluid flow when the gear is moving to the retracted position (piston is in transit to the retract side)?
Fluid will flow into both sides of the piston
* The larger surface area on the right side of the piston will cause a greater force to be applied to it resulting in the piston moving towards the retract side
113
How does the hydraulic fluid flow when the gear is in transit to the extended position (piston is in transit from the retract side to the extend side)?
Hydraulic fluid flows into the actuator behind the piston and pushes the piston to the extend side, while fluid in front of the piston is pushed out of the actuator & into the resevoir
114
How is the gear held in the retracted or extended position once it is locked into place?
Hydraulic pressure
* Retracted - Fluid pressure is held in front of the piston, piston is held all the way to the retract side
* Extended - Fluid pressure is held behind the piston, piston is held all the way to the extend side
115
What Bus is the Landing Gear located on?
The LH Main Bus
116
What kind of fluid is inside the landing gear Dampers?
An air-oil mixture (Aeroshell Fluid 41)
117
What is the purpose of the Centering Mechanism on the Nose gear?
1. To make sure that the wheel retracts into the nose straight
2. To prevent nose wheel shimmy when on the ground
118
How does our nose wheel steering work?
A Steering Linkage connected to the rudder pedals via the Stearing Arm Bracket
* It is automatically disconnected when the gear is retracted
119
How is the output of the Alternators controlled?
1. An **Alternator Control Unit** will sense the power needed by the aircraft and provide the required electrical load
2. The Left Alternator Control Units **Voltage Regulator** balences the load between the two alternators so they produce a similar output
120
Which Alternator Control Units Voltage Regulator balences the load between the two Alternators?
The Left Alternator Control Unit contains the Voltage Regulator
121
How does the Alternator convert its current from AC to DC?
Via a Rectifier which contains several Diodes
* The Diodes only allow current to flow in one direction (DC) & block the current flowing in the opposite direction
## Footnote
How an Alternator Works: https://youtu.be/jdSKlg80DjU?si=KOUx9pa1VN0iZ7Bq
122
How does the electrical system keep its power output the same, even when the Alternator is running faster at higher engine RPMs?
The Alternator is equipped with a Voltage Regulator which will limit the output of the Alternator when it is running faster.
