Aircraft Technical Manual
Jabiru Aircraft
Pty Ltd
J120, J160, J170, J200/J400, J230/J430, J250/J450 Variants
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ISSUE
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Dated: 29th October 2014
Issued By: AS
Page: 72 of 298
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Adjust the inboard wing stand until it is just clear of the underside of the wing.
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Remove both the forward and aft wing attachment bolts and rest the wing on the stand.
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The wing is now resting on the stands, positioned close to the fuselage at the normal height so
that the fuel lines and aileron cable can be left connected.
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Service the attachment point as detailed in Section 5.22.1.
CAUTION
In this position the wing is vulnerable to being bumped or jostled off the stands. This will
result in significant damage to the aircraft.
If a strut attachment requires service only 1 wing stand is required:
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Remove the wing root and wing strut fairings (both top and bottom).
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Remove the wing strut from the aircraft
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Rest the on a wing stand positioned approximately 1m (3ft) inboard of the tip of the wing.
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Service the attachment point as detailed below.
5.22.1 Attachment Point Service
– Movement Between Bolt & Lugs
Take the original bolt removed from the connection being serviced. Fit it to the holes in all the mating
parts: i.e. for a wing connection fit it to the wing lug and to the Aluminium wing attachment lugs on
the fuselage.
Wriggle the bolt in each part feeling for movement. The bolt should be a transition fit: there should
be no movement or minimal movement when fitted in each part of the connection. If excess
movement is detected sometimes it can be corrected by fitting new bolts:
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In most cases the aircraft wing-fuselage attachments will have been assembled using standard
AN4 bolts (AN5 for J250/J450). In these cases excess movement between the bolt and the lugs
may be corrected by replacing these bolts with new AN174
(1/4”) or AN175 (5/16”) close
tolerance bolts.
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Similarly, strut connections normally use AN5 bolts and excess movement between the bolt and
the lugs may be corrected by replacing these bolts with new 5/16” AN175 close tolerance bolts.
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New bolts should be lightly hand polished before installation to improve the fit.
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Note that the ideal fit has minimal or zero clearance and will require thumb pressure or a light tap
with a soft hammer for installation.
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If there is excess movement remaining even with new bolts fitted then further work must be
carried out as detailed below. This is a qualitative assessment which is best informed by
experience. If in doubt it is recommended that the maintainer re-fit the wing with the new bolt and
test for movement before continuing to any of the more significant repair processes (such as
replacing lugs etc).
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If the replacement bolts are a tight fit, re-assemble the aircraft and re-test as detailed in Section
5.12. Ensure a new bolt is used on the attachment which has been serviced.
If the holes in the wing strut lugs have worn so that standard or close tolerance bolts have excess
movement then the wing strut lug (or the whole strut assembly) must be replaced. Note that this type
of wear is unusual. Checking the more common wear modes detailed below is recommended before
replacing strut lugs.
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Carefully measure from a fixed point on the strut to the tip of the strut lug & record the reading.
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Remove the bolts connecting the lug to the strut section.
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Remove the lug from the end of the strut.
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Paint a replacement strut lug with a suitable Epoxy Etch Primer.
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Once the paint has dried, treat the mating surfaces of the lug and the strut with a corrosion
inhibitor such as Duralac.
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Fit the new lug to the strut while the corrosion inhibitor is wet. Carefully measure the position of
the lug relative to the strut to ensure the bolt hole is in the correct position. Note that small errors
here will have noticeable effect on the dihedral angle of the wing.
