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: 17 of 233
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The fastener is first loosened slightly to ensure that it is free to move on its threads. If this step is
not carried out it is possible for the fastener to corrode in place. If that happens, the friction of the
corrosion will seize the fastener, ensuring that it appears to “pass” torque checks but in fact has
lost tension and is no longer holding the assembly correctly.
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Tighten the fastener smoothly to the set torque. Any jerks or bumps when tightening can cause
the reading to be obtained prematurely.
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The torque must be obtained while the nut is turning. If you stop to reposition the torque wrench
and then the required torque reading is obtained without the nut turning, the nut needs to be
loosened a little and then tightened again so the torque reading is obtained while turning.
Table 1
– Recommended Bolt Torque Values
Bolt Size
Torque (Inch.lb)
(Core-mat or thin laminate)
Torque (Inch.lb)
(Thick, glass-only laminate)
AN3
20 - 25 (1.7
– 2.1lb.ft)
Up to 4 lb.ft
AN4
50 - 70 (4.2
– 5.8lb.ft)
Up to 8 lb.ft
AN5
100
–140 (8.3 – 11.7lb.ft)
Up to 18 lb.ft
AN6
N/A
Up to 24 lb.ft
AN4 Propellor
72 (6lb.ft)
N/A
These values relate only to steel nuts on oil-free cadmium plated threads.
For Engine Bolt Torque Values see Engine Instruction & Maintenance Manual.
The above values are recommended for all installation procedures contained in this Manual, except
where other values are stipulated.
The above values are not to be used for checking tightness of installed parts during service.
2.13 STANDARD PRACTICES
Do not over tighten bolts
Ensure a minimum of 1 full thread is clear of nuts.
Do not exceed 3 threads clear on nuts (use extra washers).
Ensure nuts are not thread-bound (i.e. the thread on the nut has hit the end of the thread on the bolt.
All spherical bearings must be fitted with a large washer on the outside of the through-bolt to prevent
the bearing case and cable releasing in the event of a bearing failure.
i.e. a ¼” washer must be fitted
to 3/16” bolts or a 5/16” washer to ¼” bolts.
AC43 or similar approved data gives guidance on accepted means for carrying out typical aircraft
maintenance tasks
– such as safety-wiring etc.
WARNING
Thread bound nuts can carry far less load and are much more susceptible to failure.
WARNING
DO NOT REUSE SELF-LOCKING NUTS
2.14 AIRCRAFT STRUCTURE
In all Jabiru Aircraft, due to the monocoque construction the majority of the structure is primary. The
components of the aircraft which are secondary structure can be identified by the fact that they are
designed as fairings and are generally removable. Examples of secondary structure are the engine
cowls, speed fairings, ventral fin and wheel spats.
