A-4M Skyhawk

by David W. Aungst

It has not been easy to model an A-4M Skyhawk without "moving mountains" in scratch building and detail work. I did it once using Monogram A-4E/F and OA-4M kits. I was happy with the result, and I always wanted to do another. But, being unwilling to tackle the conversion a second time with Monogram kits, I just let it go.

Times have changed. Along came Hasegawa with a simply gorgeous A-4E/F kit. All the desire to build another A-4M came out in force. All I needed was some time to start grafting Monogram OA-4M pieces onto it -- NOT! I knew that surely someone would release a conversion to make my life easier. Either that or Hasegawa would release an A-4M kit of its own. Just before IPMS Nationals in July of 2002, the former of these possibilities happened with Cutting Edge releasing an A-4M conversion for the Hasegawa A-4E/F kit. Of course, this was not a huge surprise, since I did help with some of the research. For a review of the Cutting Edge A-4M conversion, click here.

Then, I needed decals to put on this A-4M model. All the major manufactures have released Skyhawk decals to go with the Hasegawa (and HobbyCraft) Skyhawk kits. But Cutting Edge was first with a series of sheets dedicated to the A-4M (in support of their conversion set). For a review of the Cutting Edge A-4M decals, click here.

I originally started this model before the IPMS Nationals with the intent to finish in time to take it to Nationals so Cutting Edge would have a finished model to point at with all their new A-4M releases. With model building being a motivational exercise (for me), I needed to maintain motivation to finish this project. Sadly, after pushing hard on a number of time-critical projects completions early in the year, my motivation levels in July were starting to drop. When I hit a minor snag, the model missed getting done for National. In fact, it only finally got done this month. I have to apologize to Cutting Edge for not getting the model done in time.

I am not going to get into the basic Hasegawa kit here. I have written several reviews of the various versions already released by Hasegawa. You can go to these reviews to read all the great things about these kits. The point of this writing is to discuss the Cutting Edge A-4M conversion to the Hasegawa A-4E/F kit.

Cutting Edge A-4M Conversion

To build an accurate middle or late production A-4M requires some changes to the cockpit, especially the main instrument panel and instrument hood. Not wanting to do this on this model (and knowing the Cutting Edge was already planning to release a late production A-4M cockpit set), I chose to build an early production A-4M. The first A-4Ms (early production) were quite similar to the A-4F in their avionics fit and thus their cockpit instrumentation.

The conversion of the A-4E/F kit into an early production A-4M really only requires one fuselage cut. The cut is made on both fuselage halves in the area of the cockpit. Cutting Edge provides insert pieces that replace these areas of the fuselage so as to correct the shape of the cockpit canopy and windscreen. This change, by itself, is the only heavy surgery needed to turn an A-4F into an early A-4M. The pictures below show the cuts to the fuselage halves and the fitting of the insert pieces.

The only other surgery required is the installation of the APU exhaust port on the right fuselage. Cutting Edge provides the exhaust port. All that is needed is to create an appropriately sized hole in the correct location on the right fuselage. Sounds easy, huh? Well, it was. I eyeballed the location of the APU exhaust from reference pictures and drilled a pilot hole with a small diameter drill bit (0.037"). I then enlarged this pilot hole with a 1/8" drill bit (which matches the size of the Cutting Edge APU exhaust piece.

Note that the APU exhaust comes out parallel to the ground, not perpendicular to the lower engine intake contour. After drilling the hole in the fuselage, I twirled the drill bit in the hole as I pulled up on the angle of the drill bit. This re-contoured the hole to place the exhaust port at the correct angle. Cutting Edge created the exhaust port with a uniformly squared off pipe. The Cutting Edge instructions say to glue in the APU exhaust, then trim off the excess. I prefer getting the shape right before gluing, so I filed down one side to change the lip of the pipe to match the contour of the fuselage side. Then, I glued it in place. See the following pictures to better show what I am trying to describe.

With what I thought was the last of the surgery behind me, I continued to build the kit. I chose to use the Cutting Edge A-4 Skyhawk cockpit set (CEC48279). This is an A-4F cockpit, but it is correct for an early production A-4M. I even decided to give the main instrument panel the sandwiched acetate treatment as provided in the Cutting Edge set. See the pictures here for the outcome of my work.

Unpainted Main Instrument Panel	Completed Main Instrument Panel

Painted Main Instrument Panel	Completed Cockpit Tub

The only trick to watch on the cockpit assembly is the alignment of the back wall. If you look at the fuselage around the cockpit, you will see a diagonal panel line running down from the rear quarter point of the cockpit sill. This panel line corresponds to the location of the back wall of the cockpit. When attaching the back wall into the cockpit tub, I needed to check and recheck the alignment of the wall with this panel line. After three attempts at it, I finally got it to align where I wanted it. Once aligned correctly, the rear deck piece fits perfectly into the thinned out lip area of the fuselage at the rear of the cockpit.

After assembling the fuselage, I went to install the instrument hood over the main instrument panel and forward cockpit. Since Cutting Edge provides no piece for this in the basic A-4M conversion, I turned to the kit piece. For an early production A-4M, the kit piece details are correct (with only a gunsight, no HUD), but the piece is quite a bit too small for the enlarged opening of the cockpit. I added strip styrene around the kit piece to enlarge it so it could fill the needed space. I used 0.020" styrene strips, 0.100" wide on either side of the kit piece. Then added some small scraps to the forward area to finish the work. It was crude, but it was enough to mount the piece onto the fuselage. Gobs of super glue did the rest for fairing the enlarged instrument hood into the fuselage, under the windscreen.

It was this issue (modifying the instrument hood) that ultimately deep-sixed getting the project done for Nationals. In my opinion, it would not have been hard for Cutting Edge to provide a replacement instrument hood in the basic set. If you want to build an early A-4M (that does not use the late cockpit update set), use my measurements above and pictures below to guide your work on growing the kit instrument hood to fit the enlarged A-4M cockpit opening.


 

Modified Hood -- Top	Modified Hood -- Bottom	Modified Hood -- Installed

With the instrument hood attached, I painted the area and then attached the windscreen. The fit was less than perfect, but nothing that I could not fix. The upper nose is a rounded surface. The leading edge of the windscreen is straight. After consulting some pictures of A-4M windscreens, I found the top of the A-4M nose is a bit flattened to work with the revised windscreen, so I used a flat file and flattened the top of the nose a bit to better match the windscreen. A little super glue along the edges completed the filling of the seams.

One detail item missing in the conversion is the rain removal and de-icing vent in front of the windscreen. I added this detail using a short piece of 0.030" strip styrene. The image below (left) shows the attached windscreen with the rain removal and de-icing vent.

Another revision to the kit involved the top of the vertical tail. As an early production A-4M, this model has the squared fin tip (kit part A14). I have never liked the squared fin tip as molded by Hasegawa. The Hasegawa part has a "level" contour that just does not look right to me. After some research and study of pictures, I finally determined what bothered me about it. The tail top I was seeing in pictures of real A-4Ms was not "level". It slopes upward a bit to create a point at the leading edge of the tail tip. I attached a small strip of styrene to reshape the tail tip and used super glue to blend it in. The other image (above right) shows the modified tail tip. Right or wrong, I found this shape looked better to me.

Shortly after I made this tail tip modification, the new Ginter book on the A-4M was released. Pictures in that book further proved my opinion that the tail top sloped upwards. They also showed that a pronounced notch was formed between the moving rudder and the non-moving vertical tail. After comparing back and forth with the pictures, I came to the conclusion that the rudder was not changed from the shape it has on a rounded top tail. It appears that a new tail top cap was added which provides the squared appearance, without changing the shape of the top of the moving rudder.

The next items to get attention were the engine intakes. Cutting Edge provides the needed bulged intakes in the A-4F "Super Fox" conversion, which is a required compliment to the A-4M conversion set. These intakes pieces are simple replacements of Hasegawa kit pieces. After removing these pieces from their casting blocks, I test fitted them on the model. I was dismayed to find them a bit too small. A substantial step appeared in the outline of the fuselage where the rear of the intake piece meets the fuselage.

After some study, I found the easiest way to fix the issue was to add a spacer to the rear of the intake pieces. I pulled out some sheet styrene and laminated a 0.015" thick piece of sheet styrene onto the intake piece. This eliminated the step in the fuselage outline. The nominal increase in the thickness of the intake splitter plate is not that noticeable. I informed Cutting Edge of this problem, and they are verifying that their masters are good. They told me this sort of thing is a sign that the molds are getting old and that they will fix this for future production of the parts. The pictures below show the engine intake with the spacer in place.

 

Modified Intake - Front	Modified Intake - Inner Side	Modified Intake - Top

The outer walls on the Cutting Edge engine intakes are a bit thinner than the Hasegawa pieces that they replace. This made the gap inside the intakes more noticeable than it was with earlier builds of the kit I had done. Adding the 0.015" spacers further increased this gap, making it so I could not ignore the gap. I carefully wrapped some 0.005" styrene sheet inside the intakes to fill the gap. This was not perfect fix, but it makes the gap less noticeable when you look back the intakes.

Another item I revised was the engine exhaust. Originally, when Hasegawa released their Skyhawk kit, I investigated it and saw the two engine exhaust pieces. I thought the short one was for the majority of Skyhawk versions and longer one was the lengthened version used on the "Super Fox" A-4F and A-4M/N. Now that I am actually building a kit that I know needs the longer exhaust, I took a closer look at the kit pieces and at pictures of the real aircraft. I have come to the conclusion that the exhaust on the "Super Fox" A-4F and A-4M/N is not actually longer than the basic Skyhawk engine exhaust, but is marginally wider at its opening. Consider the following pictures.

 

A-4E Exhaust	A-4M Exhaust

Note how both exhausts are the same basic length. Also note how the contour of the areas is different at the lips. While the A-4E exhaust maintains a uninterrupted contour all the way to the exhaust lip, the A-4M exhaust has a flair in the lip to provide a slightly wider opening. It is amazing how long you can look at something and not actually see what you are looking at. I rechecked the Hasegawa instructions for the various Skyhawk kits and found they tell you to use the shorter and longer engine exhausts on various versions. It really helps when I read the kit instructions, not just browse them.

From what I can tell at this point, the shorter engine exhaust (as provided in the Hasegawa kit) is for the A-4A, A-4B, and early A-4C. The longer engine exhaust (as provided in the Hasegawa kit) superceded the short one at some point on A-4C aircraft and continued on with all subsequent aircraft until the A-4M.

The "Super Fox" A-4F and A-4M/N have a third style engine exhaust that is not provided in the basic Hasegawa kit. This new style is not hard to make, though. I created one for my A-4M model by starting with the shorter kit exhaust and attaching some strip styrene to the lip that extended it. I used 0.015" by 0.060" Evergreen strip styrene. I carefully rolled the strip to the approximate circle size and attached it to the shorter kit exhaust with liquid cement. When I cut it to length, it was a bit short, so I had to cut a small piece of strip to fill a gap left at the point where the two strip ends were supposed to have met. The following pictures highlight the change I made to the kit piece.

 

Longer Kit Exhaust	Shorter Kit Exhaust	Modified Exhaust

If you do not want to go to the trouble that I have gone to here on the engine exhausts of your A-4M models, just use the longer kit engine exhaust piece, unmodified. The difference in the final model is not really all that noticeable. It is the kind of difference that only the person who built the model will see in the final piece.

While I am on the subject of the tail area, the antennae configuration on the trailing edge of the vertical tail changed with the A-4M as compared to the A-4E/F. All the necessary parts are in the Hasegawa kit, I only needed to consult some references to figure out which pieces to use a what locations. Note that on early A-4M aircraft (and many A-4E/F), the spike antennae (kit parts D19, E31, F21, and F22) are only fairings without the spikes. Close examination of some pictures showed that there is a small rounded plug that covers the mounting points of the spikes. I hacked off the spike antennae on the kit parts and added small globs of super glue to represent the rounded plugs.

The image below (left) shows the correct early production A-4M configuration. Note that this configuration was changed again for middle and late production A-4M aircraft. Note also that while I point to where the formation light goes (part M11), the actual clear part is not yet in place on the model.

 

Vertical Tail Antennae	400 Gallon Fuel Tanks

The other image (above right) shows my work to create 400 gallon wing fuel tanks. The tanks provided by Hasegawa are the 300 gallon size. While these are correct for use on any Skyhawk version, the A-4M tended to more frequently use the larger 400 gallon type. This provided a bit more fuel, and the higher powered J57-P-408 engine could deal with the added drag.

The 400 gallon tanks were constructed using the tail fin assemblies from the Hasegawa kit (the lighter gray plastic), mated onto the Monogram A-4 Skyhawk wing tanks (the darker gray plastic). While I have no actual dimensions for the size of a 400 gallon tank, the observed size difference between the Hasegawa and Monogram tanks seems about right for what I have seen in pictures. I chose to use the Hasegawa fin assembly because I liked its shape and details better than the Monogram provided fins.

The rest of the conversion amounts to using alternate pieces already present in the Hasegawa kit.

I used the small Hasegawa kit provided ECM antennae on either side of the engine exhaust (parts D17 and D18). Early production A-4M aircraft did not get the larger bulbous antennae provided in the Cutting Edge set (although they did eventually get retrofitted).

I added the parachute brake housing under the rear fuselage (parts D11 and D28). Note that the kit provides two different parachute brake housings. The part numbers I list here are correct for the A-4M. The other parts pertain to other Skyhawk versions.

A-4M Skyhawks do not typically have the flare/chaff dispenser on the left side of the rear fuselage. They only seem to have the dispensers that are on either side of the arresting hook. So, I used the rear lower fuselage kit part with no dispenser molded into it (part A6).

All A-4M Skyhawks use the bent refueling probe, so I attached this (part E7) to the right side of the nose.
One thing not mentioned in the kit instructions pertains to the two static points molded to the right side of the nose (small triangular shapes with raised edging), just below and in front of where the refueling probe attaches. These two items are mutually exclusive. You need to carve or sand off one of these based on the type of refueling probe the aircraft has. Keep the rear static port for aircraft with a straight refueling probe. Keep the forward static port for aircraft with a bent refueling probe. Since I was using the bent refueling probe, I kept the forward one and removed the rear one.

I constructed all the other antennae and details (not mentioned here) to match what the Hasegawa kit refers to as "Scheme 2" (which is the A-4F).

I chose to keep the weapons configuration minimal. I only built up and attached the two wing fuel tanks. This was a fairly common loading for the early years of A-4M usage.

Cutting Edge provided lots of choices for markings on this model. Limiting myself to an early production A-4M limited my choices down to only two of Cutting Edge's options -- VMAT-102 and VMA-214. I have never been a big fan of the "Black Sheep", and I really like the colorful VMAT-102 markings, so I chose to go with the VMAT-102 aircraft.

 

VMAT-102 Reference Photo

Actual Model -- How did I do?

The camouflage on the model is the old standard of L.Gull Gray (F.S.36440) over a white bottom with the tops of the flight control surfaces also being white. I painted the white first and masked off the flight controls, then I painted the L.Gull Gray. I free-handed the line between the gray and white along the fuselage sides.

During the camouflage process, I also painted the entire vertical tail in white. Before painting the Gull Gray topside color, I painted the tail in Insignia Red (F.S.31136). I masked this off and then painted the Gull Gray.

Applying the Cutting Edge decals was uneventful. They worked as advertised and presented no problems. I was a bit disappointed at the color of red printed on the Cutting Edge decals. It is much lighter than the insignia red paint I used on the rest of the model. Thinking my paint might be off, I consulted my Federal Standard chart and found the paint to be dead-on matched to the Federal Standard color chip. The decals are the problem, being too light. It was mainly a problem for the large bird motif on the fuselage sides. I considered over-coating the birds with a misting of some very thin black paint to darken them a bit, but I did not want to risk messing up. So, I left them alone (and lighter than the rest of the red markings...).

I used a mixture of Cutting Edge and Hasegawa decals for the aircraft's data markings. The picture of the aircraft I have shows it actually had very little in the way of data markings. I gloss coated the model with Floquil Crystal Coat to seal the decals, then started weathering.

Weathering was done using my typical style of thinned down enamel paint washes and air brush shading. I kept the weathering rather light as the model depicts the aircraft very shortly after it was delivered. I finished the weathering with some dry brushing to pop out some surface details. For a more complete discussion of what I do to weather my models, see my posting on "Weathering Aircraft".

Great kit -- great conversion! Some care must be taken to get the fuselage cuts in the right places. With care, the conversion parts fit right into the prescribed places. With the recent release of the Cutting Edge A-4M cockpit update, it looks like I will be doing another A-4M in a late production configuration in the coming months.
 

Click the thumbnails below to view larger images:

Project Statistics Completion Date: 26 November, 2002 Total Building Time: 44.8 Research: 0.8 Construction: 11.8 Painting (includes creation and printing of custom decals): 15.6 Decals / Markings (includes creating and printing custom decals): 5.2 Extra Detailing / Conversion: 11.6