CAC  Wirraway   CA  16  

Converting the Monogram 1/48 Scale AT-6  Texan

At  first glance, the Texan and Wirraway look quite similar ,so a conversion
appears deceptively simple . As always in these cases , it turns out to be 
rather more involved .

The starting point is always getting hold of accurate drawings ,itself also
not so easy . I managed to obtain a very accurate set of Wirraway drawings
(Judged to be so as they checked out perfectly against numerous photo
scaled up side view images ) ,together with some excellent interior illustrations
from another club member,Simon Wolff .  The Texan drawings were fair but undersized ,but knowing the dimensions enabled them to be scaled correctly ,and then comparison with photo scaled side view images ,and of course the Monogram mouldings, checked out pretty well.
 
First task was to make an overlay,to reveal  any major differences ,which came as a surprise . See attached image .

The most obvious differences are well known :

ie. The Wirraway has a straight wing trailing edge , and rounded tips giving a greater span .
The tailplanes / elevators are markedly different in shape and area , as is the 
fin and rudder .
The engine is different ,with the Wirraway engine having a reduction gear housing , which requires a slightly greater cowling chord . The propeller is also
a 3 blader .
The Wirraway fuselage is shorter,and has fabric covered side panels as well .

Not so obvious are :
The windscreen and canopy , rollover truss ,rear decking and rear canopy shape,
carburettor and oil cooler intakes , shape of instrument panels , seats,flaps etc.

Wings
Having decided to proceed ,the first and apparently easy job was to cut off the outer wing panels ,and remove a wedge of material to achieve the straight trailing edge , fabricate rounded tips from laminated card ,remove rivets and re scribe
panel lines . Remove excessive ribbing effect from ailerons and slightly shorten 
their span ,and scribe new trim tab positions . Landing lights were drilled out ,foil reflectors fitted and very clear Sellotape fitted to cover the cutouts . (Thanks Michael Woodgate for the tip ).

Stall  strips were added to the inner leading edges ,and a new pitot tube made as per photos and fitted .
Small blister nav lights were made and fitted above and below each wing tip .
The later Wirraways had different flaps to earlier ones ,and a portion of the upper 
wing trailing edge was cut away at this time . New flaps were made with some ribbing on the interior surface ,as per photos. The centre section flap span was altered , as per plans and 3 actuating links added to each outer flap .
Underneath, the 4 prominent strakes were added ,and holes drilled for the 18 
practice bomb slips .

Fuselage

All rivet detail sanded off , carb intake removed , fuselage length reduced,
fin and rudder cut off .
New panels to represent fabric sides were made from 5 thou card which
had the stringer detail scribed on the inner side, and carefully glued on . The entry steps which had been removed were replaced with new items from card.

Re shaped tailplanes fitted .
New firewall fitted  , upper cowl re shaped . (no guns , only  bulges shaped from 
putty ) , to take the  different Wirraway type windscreen .
As well, a spar was fitted to the centre section as the kit had a distinct spanwise
droop.
A new rollover truss was fabricated ,to be fitted later .
The cowling chord was extended , the prominent intake on late Wirraways scribed into the approx 10 o'clock position ,and rivet detail added as per photos.

Before joining the fuselage halves, new side panel detail was added in each, according to photo references , and the tubular framework extended further to the rear,as it can be  seen due to there being no bulkhead .
New instrument panels were fabricated using the 3 layer method .
New seats were moulded using a carved wooden master .
Similarly, a new oil cooler intake was moulded from thin plastic card .

New elevators and a new rudder were made from card using a spar and  fabric
covered surface scribed on the inside as for the side panels, and trim tabs scribed in the appropriate places.
A reduction gear housing  and ignition harness was added to the kit engine . Although not completely accurate , it looks reasonable .
A 3 bladed propeller was made using a hub from the spares box with 3 reshaped
blades from elsewhere ,and counterweights from scrap. Exhaust pipes were made from softened aluminium tubing .

When the halves were joined, a new rear fuselage decking was fitted to accommodate the differently shaped rear canopy . A collision beacon and whip
antenna were made and fitted  on the rear decking .
A new fin was made from card and fitted further forward ,then faired in with putty.
Small blister nav lights made and fitted either side of the fin.
The most difficult task of all was the carving of a wooden master ,and the moulding of a new 3 section canopy which would nest reasonably with the front section open ,and especially the making and fitting of a new windscreen ,which
differs from the Texan .
The canopy/windscreen  assy used was actually the 12th attempt ,which could have been better, but I ran into moulding ,masking ,painting ,trimming and fitting fatigue and settled for it .
 Seat belts were made and fitted , and the pilot figure is sometimes inserted to give a slightly different look .
 
Landing gear
Kit u/c was used ,with slight mods to the wheel forks ,replacement of the
 torque links, and addition of brake lines . A new tailwheel assembly was
made and fitted . 
Flats were sanded on main and tail wheels.
New landing gear doors made from card .
Colour scheme

The scheme had been decided by the finding of a decal sheet for  ,I think, a Frog
Sea Vixen,which happened to have some numerals of the right shape and size to
use as side numbers on a post war trainer version . The serials were taken from a numeral  sheet for Aussie types . The stencilling was prepared on my computer,
and printed onto clear decal sheet , as there were  no suitable Wirraway decal
sheets available, and still ain't!  

The scheme is that used for a time ,namely normal roundels above and below 
wings , and Roo roundels on the fuselage sides . This was eventually succeeded
by the use of Roo roundels  all around . 
The overall colouring was Testor's Aluminium Plate metallizer ,with Yellow bands
on fuselage and wings .

Conclusion
Whilst it involved a great deal more than I first bargained on,I was reasonably
satisfied with the result ,especially as there was no 1/48 kit available at the
time ,and therefore nothing to compare it with . 
I understand there is a conversion available  , which apparently doesn't address
fully the differences between the Texan and Wirraway .

In any case, I have picked up a couple more Texan kits pretty cheaply, and am 
considering doing other versions (ie Wartime versions with rear gunner etc ).Now that I know what has to be done , they should be a little more straightforward than
the first .
When some maker does finally do a 1/48 Wirraway , I'll probably find that mine 
will be shown to be quite inaccurate , but that's life isn't it?