![background image](http://html1.mh-extra.com/html/jabiru/j450/j450_constructors-manual_3129834108.webp)
Jabiru J450 Constructors Manual
Pre-Paint>Fuselage>Fit cowling
Tuesday, April 6, 2010
108 of 343
Pre-Paint>Fuselage>Fit cowling
Objectives of this task:
To fit the top and bottom cowl to the fuselage. This is a big task that will require time and
patience: the cowl will need several test fittings and small adjustments to get the fit just right:
take your time and your reward will be a perfectly fitting, great-looking cowl.
Materials required:
Card # J13 „
Cowl components
‟ and the piano hinges pack (pictured below)
Epoxy resin and flock
5-Minute Araldite
Match the cowl joins and cut the propeller shaft hole
Start by standing the top and bottom cowls on their bases, align the front of each section
carefully and then tape both sections together using cloth tape (circled above).
Look along the side joins and check the alignment: the top and bottom sections should butt up
to each other with no gaps as shown at above left. Sand away any areas that overlap until each
join is straight and true. Mark the centre front of the propeller boss area then mark a 105mm
circle and use a jigsaw to cut the hole out. In the factory we use a circular jig as shown in the
second photo but the hole can easily be scribed with a compass. Sand any rough edges.
Fit the top cowl to the fuselage
In this step we will need to make up a spacing jig (shown at
left) that will keep the front of the top cowl 20mm behind the
propeller flange and 15mm above and centred on the propeller
shaft extension, plus a 3mm spacer on top of each ram air
duct. Wooden blocks cut to size are fine for the purpose.
Tape the jig into place and test fit the top cowl.
Once the front of the top cowl is correctly positioned and
centred on the propeller shaft extension, move to the back
of the cowl and ensure that it is centred side-to-side: mark
the fuselage waterline on each side of the fuselage (photo at
right) and measure up to the cowl from that line then move
the cowl side to side until the distance is equal on both
sides. Recheck that the front of the cowl is still centred.
When the cowl is centred at the front and back, mark the
centreline on the cowl and on the fuselage in front of the
windscreen and then tape the cowl to the fuselage.
Same both
sides
Waterline