DIAMOND 42
TECHNICAL SPECIFICATIONS
FLIGHT CONTROLS
Ailerons (Control Rods) : 4 hinges secured in position by roll pin. Absence of roll pin can lead to loss of
hinge pin and subsequent loss of flight safety.
Elevator (Control Rods):
* 5 hinges
*Electrically operated actuator
* Limits elevator UP travel to 13° as soon as
1) Power setting on both engines exceed 20%
2) Flaps in LDG configuration
* Full deflection is regained (15.5°)
1) Power setting on one engine is below 20%
2) Flaps NOT in LDG configuration
* Amber G1000 display in case of malfunction
Wing flaps (Control Rods) :
* Electrically operated
* 2 piece construction
* Inner part – centre wing (4 hinges)
* Outer part – wing (6 hinges)
* Secured in position by roll pin. Absence of roll pin can lead to loss of hinge pin and subsequent loss of
flight safety.
* UP and LDG positions are protected by limit switch to guard against overrunning end position
Rudder (Cables):
Connected to vertical stabilizer by 4 screws
POWER PLANT
* 2 x Thielert TAE125 (max power 99KW at 2300 RPM)
* Liquid cooled, 4 cylinder, 4 stroke diesel engine with wet sump
* Inline construction
* Common rail direct injection
* Propeller speed reducing gear 1 : 1.69
* Digital engine control with integrated prop governor with separate oil system
* Turbo charger with intercooler
*Engine can only be operated with Master Switch ON
* Each engine has an ECU powered by generator (when at least one engine is running). Otherwise
powered by battery
PROPELLER
* Hydraulically regulated 3 bladed constant speed feathering propellers
* Propeller pitch control system is integrated into engine
* Gearbox oil is pumped into propeller hub to change blade pitch angle
* Oil pressure is regulated by governor valve controlled by ECU
* Increase in oil pressure leads to decrease of pitch and high RPM
* Decrease in oil pressure leads to increase in pitch and low RPM
* Pressure accumulator is a nitrogen oil type at a pressure of 290 PSI
Feathering :
* Engine must be shut down with Master Switch
1) This will open electric governor valve
2) Oil will flow back from prop hub
3) Blades will move into feathered pitch position
4) Electric valve at accumulator will close and oil pressure is restored in accumulator
* Feathering is possible at or above 1300 RPM. If below then pitch remains below start lock position and
speed must be increased to increase RPM
Un-feathering :
* Engine master switch must be turned ON
1) Electric valve at accumulator will open
2) Pressure will move blades into low pitch position
3) As soon as propeller starts, accumulator will be refilled
* High RPM on ground should be avoided
* Never move prop by hand
Power Lever :
* ECU controls
1) Manifold pressure
2) Injected fuel quantity
3) Propeller speed
* Low power and gear up situation produces aural warning & “CHECK GEAR” caution on PFD (if installed)
* Power lever should be moved slowly in order to avoid over speeding and excessively rapid RPM
changes
Engine Master :
* Provides power supply for
1) Pre-heat system
2) Un-feathering accumulator valve
3) Engine
*Engine can be cranked only if Master is ON.
* Shutdown is by turning Master OFF
ECU – Swap :
* ECU swap switches – one for each engine
* AUTO – for normal operations
* Normal – controlled by ECU A
* Failure of A => automatic switch over to B
*If AUTO fails => manual switch over to B
ECU – Test :
* Possible on ground as well as in the air
* One button for each engine
* 2 functions:
1) IDLE: RPM below 900
* ECU performs switch from ECU A => ECU B with propeller cycling (slight shake of engine may occur)
* Then switches of ECU B => ECU A
* Both caution lights will extinguish
2) Above IDLE: RPM above 900
* If ECU A or ECU B caution message is displayed ECU test button can be pressed for more than 2
seconds to reset message
* Reset is possible only once
ALTERNATE AIR :
* Used in the event of power loss due blocking of air filter or icing
* Lever serves both engines simultaneously to draw air from engine compartment
FUEL SYSTEM :
* Fuel is stored in wing tanks
* Each wing tank supplies to it’s respective engine under normal circumstances
* Fuel is injected directly into cylinders at high pressure through injection nozzles (one per cylinder)
from fuel supplied by common rail
* Fuel inside the rail is generated by a high pressure pump which receives fuel from a low pressure
pump
* Both pumps are powered mechanically by engine
* Rail pressure is controlled by ECU
* Both sides of fuel system are interconnected by crossfeed lines
* Fuel that is not injected is fed back into appropriate wing tank
SELECTOR VALVES :
* Each engine has a selector valve
* Positions are: ON => X-FEED => OFF
* In the X-FEED position, engine will draw fuel from opposite tank for extended range and to keep fuel
balanced during single engine operations
* With fuel selector valve, both feeding and return lines are switched
* Selector for an inoperative engine must be ensured OFF
* Do not operate both valves on X-FEED
* Do not take off on X- FEED
* Do not shut down with selector valve due to risk of HP pump being damaged
Positions:
ON : Same tank same engine
X-FEED: Opposite tank same engine
OFF: No fuel flow
OIL SYSTEM : (involves 2 systems)
* Wet sump for engine and turbo-charger. Cooled by a separate cooler on underside of engine –
checked by a sip stick
* Lubricates gearbox and prop-governor system. Gearbox oil quantity may be checked by inspection
glass in the front side of lower cowling
LANDING GEAR :
* Fully retractable, hydraulically operated, tri-cycle landing gear with oleo struts
* Hydraulic pressure provided by electrically operated hydraulic pump
* Gear selector switch powers electrically actuated hydraulic valves which provide required hydraulic
pressure for gear actuation
* Extension takes 6 -10 seconds
* Hydraulic pressure keep landing gear in retracted position
* Springs assist extension and keep gear in down position
* Warning horn will sound for following:
1) One power level below 25% power – gear retracted
2) Flaps in landing position – gear retracted
* Squat switch prevents inadvertent gear retraction on ground even in UP position
* Retraction before 156 knots
* May remain extended up to 194 knots
* Pulling emergency gear extension lever releases hydraulic pressure and allows gear to fall free
Caution: Place selector in DOWN position before operating emergency extension
