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Aircraft Service Manual
Jabiru Aircraft
Pty Ltd
JTM001-1
J120, J160, J170, J200/J400, J230/J430, J250/J450 Variants
REVISION
1
Dated: Nov 2011
Issued By: SW
Page: 50 of 233
Figure 18
– Alignment Measurements
Mark the position of the straight edge in front and behind the wheels. Positions are marked at 1.5m
nominally either side of the wheel centre.
Take measurements from the straight edge positions to the centreline of the fuselage.
Compare the measured distances to see if the wheels have toe-in or toe-out.
Camber is the vertical angle of the wheel to the ground. It is to be measured (using a digital
protractor or similar) using the end of the axle or the brake disk as a reference. The aim is to have
the wheel vertical when the aircraft is fully loaded.
Toe in / toe out and the wheel camber angle are related in that when the wheel has camber it
behaves like a cone and wants to track in a circle around the point where the centreline of the axle
hits the ground. The toe of the wheel is used to compensate for this so that the wheel doesn’t try
and pull in or out on the leg as the plane taxis.
A camber angle of 1.5° (with the top of the wheel leaning slightly outboard relative to the bottom of
the wheel) is recommended for all models when unloaded.
Depending on the type of operation the aircraft is normally used for the operator may alter the
camber angle slightly
– i.e. if the aircraft is normally loaded heavily a slightly higher camber angle
may be used.
Toe-in for the main wheels is set at between 10mm and 0 mm. This is for an empty aircraft.
If adjustments are required, washers are used as spacers between the stub axle and the
undercarriage leg.
If a combined toe / camber adjustment is required a higher stack of washers is fitted to the bolt
requiring most adjustment.
After packing the wheel alignment must be checked again
– this can be done by dry-assembling the
wheel with packing washers but no flock and then re-measuring the aircraft
– taking care to pull the