Jabiru J450 Constructors Manual
Testing>Flight testing
Tuesday, April 6, 2010
327 of 343
Sequence #1
– First start, ground run and taxi
Print and use the Flight Testing form
Sequence #1
for this sequence.
Locate the aircraft on a suitable run-up area with no gravel or small stones in the area under
the propeller, point the nose of the aircraft into wind and chock the main wheels.
Pre start
Remove the upper cowling and set it aside. Remove the spark plugs, turn the Master switch
ON and leave both magneto switches OFF. Press the starter button and allow the engine to
crank over. Watch the
Engine Oil Pressure
(EOP) gauge for the first indication of oil
pressure. Stop cranking once oil pressure is seen. Refit the spark plugs and upper cowling.
Start
Turn both magneto switches ON and pull the choke ON. Turn the fuel tap ON, turn the fuel
pump ON and listen for its operation for 10 seconds. Turn the fuel pump OFF.
Press the starter button; listen for the click of the solenoid, and the winding of the starter
motor. The engine should start within a few revolutions, usually as soon as fuel reaches the
carburettor. Listen for the sound of the starter motor disengaging after engine start.
Watch the EOP and if it does not rise in the first 10 seconds after starting shut the engine
down and call the mechanic. The EOP range should be from 220 to 525 kPa.
Idle condition
The idle should be smooth and may be up to 1400 rpm with the choke on, and up to 900-950
rpm with the choke off. Note that the requirement for choke will vary with OAT. Check the
Engine Oil Temperature
(EOT), it should rise slowly and steadily to 50 – 60 °C, and the
Cylinder Head Temperature
(CHT) should rise to 85 – 105 °C. The
Exhaust Gas
Temperature
(EGT) gauge (if fitted) should read between 425 – 485 °C.
Once the engine has warmed (EOT 50°C or more) then you may proceed, but before you do
the idle speed must be adjusted correctly in accordance with the procedure in the next step.
Idle speed adjustment
Once the engine has been warmed to operating temperature then the idle speed must be
adjusted before proceeding. This idle speed adjustment procedure will require 2 people: one
inside the cabin operating the engine and one adjusting the idle stop on the carburettor.
Stop the engine by turning both Mag switches to the OFF position. If the engine will not stop
it means that a Mag earth wire is not correctly connected – in this event stop the engine by
turning the fuel tap OFF and waiting until the engine stops. Connect the earth wire before
re-starting the engine.
Remove the upper cowling and set it aside. The Pilot side throttle input shaft has 2 alloy
collars while the Co-Pilot side has 1 collar. Loosen all 3 collars with an Allen key, working
through the holes in each side of the instrument panel housing. Start the engine and adjust the
idle stop on the carburettor until the engine idles at 900 rpm. Stay well clear of the propeller!
Adjust the collars on the input shafts so that when the engine is at idle the collars on each
input shaft are just touching the back of the input shaft pivot block. Lock each idle collar in
place. With the engine turned OFF push both input shafts to full throttle and adjust the Pilot
side collar so that it is just touching the other side of the pivot block and lock it in place.
Re-test the idle and make any further adjustments required. Replace the upper cowling.