Thursday, October 14

Build review part I: 1/48th scale O-2A (late production) USAF observation aircraft from ICM Models

ICM's recent 1/48th scale O-2A (late production) USAF Skymaster is the subject of Andy King's two-part build guide. In this first part, we see how the kit goes together and what to look for, and what he thought of the kit in his review...
Build review part I: O-2A (late production) USAF observation aircraft.
From ICM Models
Kit number #48292
1/48th scale
196 parts
Model Dimensions: 185mm х 242 mm
Markings: 
-U.S. Air Force s/n 68-11067, Forward Air Control, Laos, 1970
-U.S. Air Force s/n 68-10999, Fit Lt D Robson (RAAF), 19th TAAS USAF, Vung Tau, Vietnam, 1969
-U.S. Air Force s/n 68-11013
Price: $45 USD from Hobbylink Japan
Product Link on the ICM Website
The subject: O-2A (late production) USAF observation aircraft
The O-2A (or Oscar Deuce as it was nicknamed) was developed for military use from the Cessna 337 Super Skymaster to replace the Cessna O-1 'Bird dog' spotting aircraft. An order was placed in 1966 by the USAF for O-2A's and B's and the aircraft first flew in January 1967, entering service in March the same year.
Mainly used as a FAC (Forward Air Control) aircraft, the role was to mark targets for bombers and for this LAU-59/A rocket pods carrying seven 2.75inch FFAR's (Folding Fin Aircraft Rockets) in each pod and loaded with white phosphorous (or 'Willie Pete' as it was known to the aircrews) were fired from two pylons under each wing. 
Over 500 O-2's were built and saw service during the Vietnam war until it was eventually replaced in the FAC role by the OV-10 Bronco although the O-2 still served in the USAF and Air National Guard until the late 1980s.
This particular version from ICM is a late production O-2A in that one of the criticisms of the original design was the limited view from the cockpit through the glazing, something very detrimental for an aircraft used in the spotting role. The new design featured an enlarged window on the port fuselage and extra glazing in the door and fuselage on the starboard side but even this wasn't as effective as the port window could not be opened which did not help with ventilation plus the pilot couldn't hear any gunfire from the ground, also the view was limited when someone was sitting in the right-hand seat.
The Kit: 1/48th scale O-2A (late production) USAF observation aircraft from ICM Models
The kit itself contains just three sprues in grey polystyrene, two clear sprues and a decal sheet (with a total of 196 parts). All parts are well moulded, however, there is some flash present and there are a couple of prominent mould-pin marks on the sides of the cockpit interior, also the plastic is a bit rough on some exterior surfaces and could do with polishing out.

Some of the parts of interest of this kit...
 Another thing to mention about the plastic ICM use is that it is on the soft side, so don't use any paint that has 'bite' to it such as lacquer paint without using a primer first, something I found out the hard way after priming another ICM kit with a Games Workshop Chaos Black rattle can. Also, note that the model requires 10 grams of weight in the nose to avoid it being a "tail-sitter" and due to the spindly design of the main undercarriage and knowing just how soft the plastic is, I ordered a replacement set cast in brass from Aerocraft Models as well as wing struts. 
Initially, I was going to strengthen the undercarriage myself, but with the extremely reasonable retail price of the Aerocraft undercarriage and struts, I felt it would save a lot of time and heartache.
Detail-wise the kit features nicely recessed panel lines, the top of an engine for what you can see through the front fuselage and the cockpit is pretty well kitted out with a decent looking radio rack for the back and individual decals for the instrument panel. Having looked at reference pictures, the lower half of the cockpit appears to be lined with a dark green padded material (possibly a ballistic material) and this needs adding plus sun visors in the front roof glazing. Quite how I'm going to replicate the ballistic material I don't know but I think with the addition of that, seat belts and wiring for the radio's the cockpit will look quite busy.

Three marking options are provided, all for USAF machines from the Vietnam war:
-U.S. Air Force s/n 68-11067, Forward Air Control, Laos, 1970
-U.S. Air Force s/n 68-10999, Fit Lt D Robson (RAAF), 19th TAAS USAF, Vung Tau, Vietnam, 1969
-U.S. Air Force s/n 68-11013
 The kit includes a masking template for the cabin glazing printed on the instructions. 
Decals are well printed and in register, although some of the smaller stencils are barely legible unless you own a microscope. One thing to watch with ICM decals is that they are very thin and can put up a fight when applying them as they want to curl up into a little ball at any opportunity.
The Build:
Anyway on with the build and we start with the cockpit, wheel wells and engine compartment. Here are the main parts of the fuselage that go together pretty simply before adding any detail.
As stated the first thing to add is the dark green ballistic material as this will also hide the pin-marks and for this, I scribed 2mm squares onto a strip of thin plastic sheet using the end of a fine round file rather than a dressmaker's needle.
I then ran some liquid glue around the squares to get rid of any swarf and also to soften the edges a bit, after which I applied the plastic sheet to the fuselage interior, taking care to avoid covering the apertures for the transparencies. 
The instrument panel had the levers for the undercarriage, throttles and flaps made from thin plastic added to the centre console as well as some rectangular block with four holes in as these are quite noticeable details on the real aircraft. 
I also added slings to the M16's on the port side of the cockpit using thin strips of masking tape.
The pilot's control wheel had some buttons added on the top using heat stretched sprue, also the holes for the right co-pilot's seat were filled in as the seat needs moving back about 2mm give or take. I boxed in the centre console as you can see into the cockpit from the front wheel well plus the exhausts for the front engine were drilled out but ideally, these could do with replacing with brass tubing.
The radio rack for the rear fuselage, cabin floor and engine were assembled and when set these parts and the interior were sprayed with Tamiya LP-3 Flat Black. This is the first time I've really tried the new Tamiya lacquer paint and it sprayed beautifully, in fact, it reminded me how Tamiya acrylic used to spray years ago with no issues so I will definitely look at investing in more of this paint range. Back to the model and once the black had dried I then sprayed a mix of Tamiya XF-4 Yellow Green and XF-5 Flat Green to the interior surfaces not covered by the ballistic padding, front gear bay and engine compartment, the padding was then hand-painted with Vallejo 70980 Black Green. 
ICM supply decals for the dials on the instrument panel and for this I used my RP Tools round punch and die set to punch out the decals rather than try to cut them individually from the backing sheet. To help with this I used a thin plastic sheet as a backing piece.
While the dials were soaked in water I put some Johnsons Kleer into the recesses so that the decals would adhere to the matt painted surface better and with all the dials in place, I dropped Tamiya X-22 Clear onto the top of them to represent the glass.
To highlight the details, the cockpit was dry brushed using a Vallejo acrylic light grey with metallic chips done with a silver pencil. All that was needed at this point were seat belts so these were made from thin strips of masking tape with buckles made from fuse wire and painted with Vallejo 70921 English Uniform.

With the cockpit painted it was time to put the fuselage together, not forgetting to add 10 grams of weight to the nose otherwise you'll have a tail-sitter for a model. The cabin glazing was washed in IPA (Iso Propyl Alcohol) to remove any grease then dipped in Johnsons Kleer and left to dry. The reason for this was I didn't want any of the transparencies dropping inside the model during final assembly. the support for the large cabin window on the port side is VERY thin and prone to being damaged and as I was going to use super glue to fix the glazing in place, Kleer would protect the clear parts 'fogging' from the glue's vapours.
Before the fuselage was glued together, the test fitting showed a large gap on the top of the nose so I removed some material from the front firewall and engine insert after which the fuselage was able to close up. Test fitting the front engine cowling showed another large gap but after careful sanding of the top of the starboard fuselage, that gap was reduced also.
The rear fuselage (part A36) was a pretty good fit and required just a touch of filler. The exhausts are moulded solid and I tried drilling them out but decided to open up the holes instead and replace the exhausts with tubing after painting the model. The joints on the underside of the fuselage and the top of the cowling were surprisingly big so I filled these with Revell Plasto rather than the polyurethane stuff I normally use and set it aside to cure thoroughly.
When ready the joints were gently sanded with 320 grit paper and water, followed by 500-grade paper then buffed with a ladies nail buffer to polish the plastic. Because the plastic ICM use is so soft it is very easy to put deep scratches in it but if you take your time and use the grades of wet and dry paper mentioned then you should be OK.

I test fitted the cowling front (part A44) and it just needed the bottom lip thinning before it would fit properly, after which I sprayed the inside with my interior green mix.
I cleaned up and thinned the propeller blades to scale thickness...
The part was glued into place but it also required some filling all around. With all the fuselage joints cleaned up, I re-scribed the panel lines that were lost during sanding then ran some liquid glue over them to clear out the swarf.

The upper wing was glued into place followed by the lower wings and air intake on the top along with the two tail booms as although the instructions show the lower wings to be attached at step 60, I saw no reason as to why they couldn't be glued at the same time as the upper wing (not forgetting to drill the holes for the weapons pylons). The joints between the lower wings and fuselage were filled with Milliput then smoothed out using a cotton bud (Q-Tip) and water so as not to destroy the surface detail. The ailerons and wingtips were fitted and these also needed some filler, in hindsight I should have just sanded back the edges of the outer wings until I was able to close up the gaps on the ailerons then fit the wingtips (parts A9 and A32), something to remember for next time.
The air intake on the top also needed some filling and sanding;
After the tail booms had been glued together they were inserted into the fairing on the wing and checked for alignment before gluing into place and as the plastic is soft the rear elevator was fitted by just gently bending the booms apart.
As mentioned above the undercarriage was replaced with brass items from Aerocraft Models as the kit supplied items will collapse in a short space of time due to the weight needed to prevent a "tail-sitter"
The gear bay door cover wasn't a brilliant fit so Milliput was used here to fill the gap, again smoothed out using a cotton bud and water. The only thing to note here is that the brass parts needed sanding to remove seam lines and the stub where the molten brass is poured into the mould. The same deal applies to the Aerocraft wing struts which were an OK fit, but needed some filler where they join the wings. The nose undercarriage was modified slightly as the axle is hollow tubing so I replaced it with plastic rod drilled out either end (also I lost the brass axle so needed to make a new one anyway).

With the airframe more or less built I added the wing pylons and other bits, the only issue I had here was with the four LAU-59 rocket pods as, during clean up, two of them took on an oval shape rather than a circular section. This was probably due to me being too heavy-handed when sanding the joints but it does happen with two-part gun barrels in tank kits as you can end up with 'flat-spots' and the reason many armour modellers prefer turned metal barrels. As there are no aftermarket LAU-59's on the market I had no choice but to fit one pod on either side as the other two went into the bin. I could have gone with the supplied SUU-11B gun pods but according to the memoirs of a FAC pilot, these were rarely fitted.

Parts B47, B56 and the port fin had holes drilled into them as an aerial cable runs between B56 and the fin and a whip aerial fits into B47 on the upper fuselage.
Part B56...
The hole drilled into the port fin...
During clean-up, I managed to break the horizontal aerial on the top of the fuselage (part B53) so this will be replaced after the model is painted.

With the final bits in place, the build was complete and ready for painting.
It was only after taking these photos that I noticed the join on the upper nose was still visible however after looking at reference pics there is a panel line on the real aircraft so one was scribed in using a dressmaker's pin in a hand vice and electrical tape as a guide. I used to use Dymo labelling tape for this but the newer stuff is very soft and useless for this work.
Altogether this is a nice kit but there are some pitfalls, the main one being the soft plastic that ICM use as cleaning up after any sanding left scratches that took time to polish out. Also when re-scribing panel lines I use liquid glue to remove any swarf and this left visible marks on the plastic in places where the glue had eaten into the plastic so be warned.
Fitting the transparencies wasn't too bad apart from the front windscreen as the surface areas for gluing it into place are very small, hence the need for coating the clear parts in Johnsons Kleer (Future) and using super glue to fix it in place.
ICM has covered a long-neglected subject as although there have been other kits of the O-2A we were long overdue for a modern tooled kit of one and bearing the above issues in mind, if you take your time and test fit parts regularly you shouldn't have any trouble assembling the model.
In part 2 I'll be painting and finishing the model so keep a look out for that.

Andy King

Thanks to ICM Models for sending this to Andy to build and review for you...
Find out more about Andy's Modelling on Andy King's Model Blog...