Jabiru J450, Руководство конструктора, Страница: 333 / 343

Jabiru J450 Constructors Manual
Testing>Flight testing
Tuesday, April 6, 2010 333 of 343
1. Adjusting the Rudder Pedal Pushrods
If the rudder pedals are displaced fore and aft when the aircraft is in straight and level flight,
adjust the rudder pedal pushrods that connect the rudder pedals to the steering yoke until the
pedals sit level. Retest and adjust as required.
2. Adjusting the Rudder Cable
If pressure is required on one rudder pedal to keep the aircraft straight in straight and level
flight: if pressure is required on the right pedal then the rudder cable must be shortened, while
if pressure is required on the left pedal then the rudder cable must be lengthened.
To alter the length of the rudder cable the rod ends must be removed from the connecting
bolts, the lock nuts must be loosened and each rod end must be moved and equal amount,
either in or out. Note that the rudder pedal stops must be readjusted at the same time.
It is not possible to predict the amount of adjustment required as each case will be different,
but as a general guide try moving each rod end one full turn for a total of 2 full turns (1 at
each end of the cable) and then test fly that configuration to see if more or less adjustment is
required. Take careful note of each change and the effect on the flying qualities of the aircraft.
Care must be taken: the threaded end of the rudder cable must always be visible through the
safety hole in each rod end, the lock nuts must be tightened against each rod end and the
Nyloc nuts on the connecting bolts should be replaced before each test flight.
3. Adjusting the Angle of Incidence (AoI)
Use this procedure only if the aircraft repeatedly rolls towards the same wing just before the
point of stall in a clean configuration as explained earlier in this task. The wing that drops is
stalling slightly ahead of the other wing and it will need to have its angle of incidence reduced
by a small amount. You will need to fit the eccentric bushes to the wing that drops to decrease
the Angle of Incidence by 0.4°, which will entail placing the offset hole in the front bush UP
and the offset hole in the rear bush DOWN. This very small change will be all that is required.
This procedure can be carried out without removing the wing from the aircraft.
Remove the wing root fairings. Chock the main wheels and support the outboard end of the
wing. Remove the nuts from the wing root bolts and then very carefully tap each bolt out: as
each bolt is removed, replace it with a length of stout wire of approximately 5mm thickness so
that the wing root will not drop and damage the fuel lines or the side of the fuselage. Note
carefully the position of the flat washers for reassembly.
Now the front wire can be removed and the wing can be slightly lifted so that the front bush is
raised above the mounting lugs on the fuselage and the wing must then be held in this position
by placing a bolt back through the front wing lug on the fuselage so that the wing lug can sit
on the bolt. Take your time and make sure that the wing is unable to move or fall from this
position by making sure that the outboard end of the wing is firmly supported fore and aft as
well as underneath.
Heat the front bush with a soldering iron and remove it completely from the lug and clean
away all of the flock from the bush mounting hole in the lug then tap the hole to 5/8” UNC in
preparation for screwing in the eccentric bush.
It is very important that the tap be exactly square on to the lug and not angled in any way.
It may be necessary to remove a small amount of material from the leading edge at the wing
root to allow a straight approach to the hole in the front lug when tapping the thread.
The wing root fairing will cover a small cutout here if it is required.