Sword Models 1/72 Turret-less TBM Variants

6 November 2020: Norm Filer provided the following picture and notes on the TBM-3R that he built from the Sword kit described below:

"No significant issues. The usual vague instructions and soft plastic which leads to large sprue gates and sometimes not square mating surfaces. When it is done it looks good."

Original Post:

Sword Models has just released 1/72 scale model kits of airplanes that are not sexy but were ground-breaking in their time, in this case examples of the repurposing the WW II General Motors TBM Avenger, which had been designed, developed, and initially produced by Grumman as the TBF. Attacking capital ships with torpedoes had gone out of fashion by the end of the war, but the TBM was big and sturdy and there were a lot of them left over. As a result, they were quickly and easily adapted to other missions now needing a suitable carrier-based airplane to accomplish. For more on the U.S. Navy TBMs, see http://thanlont.blogspot.com/2015/07/post-war-eastern-tbm-variants.html

All three kits contain the same plastic, including the canopies for each kit. Only the instructions and decals are different.

The first picture is the beautiful art on the cover of the box; the second are profiles of the markings in the kit. 

SW72130 TBM-3SAvenger AS.3/4/6

Unfortunately, the identification of the kit contents is somewhat inaccurate in some places. Instructions and decals are provided for an AS.3 operated by the Royal Canadian Navy (not a TBM-3S, per se) and an ECM.6 operated by the Royal Navy. The AS.4 retained its turret, which is not provided in the kit; I'm not sure that there actually was an AS.6. Only a few (eight?) Royal Navy versions was converted to the ECM.6.

SW72131 TBM-3S2 Avenger

You'll note that the RCN AS.3 depicted here has a slightly different canopy than the one in SW72130 and there are two variations of the -3S2 canopy. The TBM-3S2 was preceded by the very similar TBM-3S (consistent with U.S. Navy designation practice, there was no TBM-3S1), about which more later.

SW72132 TBM-3R Avenger

My personal favorite, the first of the really capable CODs. For more on this variant, see http://tailhooktopics.blogspot.com/2013/01/tbm-3r-cod.html

Note that Sword also plans to issue yet another variant later this year, the very colorful TBM-3U. For more on this particular TBM, see https://tailspintopics.blogspot.com/2020/08/the-colorul-tbm-3u.html

I have yet to do more than fondle the plastic (and haven't seen any online reviews so far) but my first impression is that these kits are highly detailed and excellent quality. The builder will need to pay close attention to the pictorial instuctions because all of the parts, including canopies, for each variant are in each kit. There will be a few parts left over.

Another configuration detail that differentiates the various TBMs is the presence or absence of the external tailhook, which is dependent on which particular TBM-3 or -3E Bureau Number was the basis for the conversion. This is described in the first link above.

More later...

Grumman F7F-3P Tigercat

The Navy adapted most of its fighters for the photographic-reconnaissance mission. The big Grumman F7F Tigercat was no exception and it was probably the most capable of the propeller-pulled ones. Its five-camera capability included tri-metrogon coverage, which was basically three cameras providing horizon to horizon photographs that could be merged into one. The most forward camera station was for detailed vertical pictures; the pilot was provided with a periscope to aim it. The fifth camera took "flat" oblique pictures to the left side of the airplane.

The aft cockpit was usually occupied by the removable reserve tank since there was nothing for a second crewman to do and the belly tank would block the periscope view. A metal panel often replaced the aft cockpit's plexiglass canopy.

The periscope hatch in the belly just aft of the cockpit was provided with louvers that the pilot opened when taking vertical pictures, pictured here from the left side of the fuselage.

The pilot viewed the image in a mirror located on the floor just left of center.

The big funnel is the viewing end of the periscope (the small black one on the right at the end of a long tube is the pilot's relief tube). The mirror would be mounted in the square plate just in front of it.

When not in use, the open camera ports were covered by metal plates slid into and out of place by cables pulled by electric motors.

The bottom ports and access hatches, looking aft from the right side:

The right-side port (the cover isn't fully closed):

The left-side ports:

 

The four cannons located in the wing leading edge between the fuselage and engines were removed. However, it appears that there were at least provisions for the .50-caliber machine guns mounted in the nose since the gun ports are present.

For a summary of the various Tigercat versions, see https://tailhooktopics.blogspot.com/2016/11/grumman-f7f-tigercat-variations.html

A-3 Versions Windows

A question has arisen with respect to the number of windows on the side of the fuselage of the A-3 mission variants. The variants were derivatives of the A3D-2 bomber that had the bomb bay deleted and the forward fuel cell moved aft to create a cabin just aft of the flight deck. For more, see https://tailspintopics.blogspot.com/2010/09/mighty-skywarrior.html

The variants were the A3D-2P (RA-3B), A3D-2Q (EA-3B), and A3D-2T (TA-3B). Some A3D-2Ts (and reportedly an EA-3B) were outfitted as a transport and at least one was converted to an EA-3B. Subsequent repurposing of the RA-3B resulted in the ERA-3B.

The A3D-2P was easily recognizable for its camera port fairings and the single porthole on the side of the fuselage. The A3D-2Q had three windows and a door on the right side of the fuselage; there were no windows on the left side of the fuselage as the left side of the cabin was filled with consoles. The A3D-2T had four windows on the left side in addition to the windows and door on the right side.

As it happens, all of the variants were built with provisions for all the windows on both sides of the fuselage with the exception of the A3D-2P. It is likely that on them at least the third window going aft on the left side and the door on the right side were deleted during the redesign to reconfigure the aft end of the cabin as a small bomb bay. It's possible that provision for the aft window opening on each side of the fuselage was also deleted but an early Douglas access-panel drawing has it present.

Some have questioned why the versions were all built with the window provisions, some of which were then plugged. The answer is that metal airplane structure is made up of bits and pieces. Every one is created using patterns/dies (aka tools) to cut it to size, bend it to shape, drill holes in it, inspect it, etc. More tools (aka jigs) are used to combine parts into assemblies and so on. As a result, if the weight penalty is small enough, in order to minimize nonrecurring cost and to some extent take advantage of the learning curve and minimize investment in spare and repair parts inventory, etc, when an assembly is to be used for multiple applications, the lowest common denominator configuration is designed and then modified as required. There were other production control benefits as well,

Others have questioned that there were provisions for windows when none are apparent in photos of the airplane. The answer is that putty and primer obscure the presence of the frames and inserts, particularly if the pictures are not very high in resolution.

This is a picture of the left side of an EA-3B undergoing a major overhaul, stripped down to bare metal.

 Angelo Romano

This is a picture of the right side of the fuselage of an ERA-3B. The outline of the window frame aft of the porthole is faint but definitely present on the original scan.

Rick Morgan

However, for any model in a scale less than full size (if then), the time to depict the presence of these frames could probably be best spent elsewhere.

AD Skyraider Dive Angle Sight Post

Lockheed P2V Neptune Crew Entry Hatch

 21 April 2020: In turns out, thanks to photos and illustrations provided by Ed Barthelmes that the P2V-5 (and presumably earlier and maybe the P2V-6) and the P2V-7 had slightly different entry hatches. The photos I took and originally posted were of the nose wheel well of a P2V-5FS.

For more on the P2V-5 versus the -7, see http://tailspintopics.blogspot.com/2020/03/lockheed-p2v-5-vs-7-neptune.html

All P2Vs had a crawl way to the left side of the nose-gear wheel well (which is why the well is offset to the right) and beneath the flight deck for access to the aircraft and to go between the nose and the forward crew compartment. This is a P2V-5 illustration:
 

Access to the crawl way from the ground was through the aft left side of the nose wheel well (note that the above illustrates the access point for P2Vs -1 through -6; because the nose wheel well was located farther forward on the P2V-7, the opening was located farther forward in the crawl way).

This is from the P2V-5 manual; note the width of the wheel well relative to the ladder:

The access could be closed off by sliding panels, in this case a picture of the P2V-5's.

Note the folding ladder attached to the aft end of the wheel well, again on a P2V-5.

Note that the earlier P2Vs had a wider nose-wheel well than the -7.

This is a picture of the hatch in a P2V-7; note that it slides open vertically and appears to be wider than the -5's.

 Ed Barthelmes

 This one shows the ladder (and the sole of somebody's shoe):

Ed Barthelmes

This is the open hatch in the wheel well of a P2V-1 (it isn't evident what closed it off; I suspect that the ladder was removed to discourage entry to the airplane after it became a museum display):

 This is the location of the opening in the floor of the forward crew compartment.

 Ed Barthelmes

There was another hatch on the bottom of the fuselage aft of the bomb bay for entry to the fuselage aft of the wing (it was possible to go between the forward and aft crew compartment but it required crawling over the wing spar) as shown in this P2V-5 illustration provided by Ed Barthelmes.

Kitty Hawk 48th Scale FJ-2 Cannon Bay Door

There's a good review of the Kitty Hawk FJ-2 in the current (May 2020) issue of FineScale Modeler. One error I noticed in either the build or more likely the kit instructions was that the access door was mounted as if it were hinged at the bottom and lowered to be a shelf. It was actually completely removed and set aside on FJ-2s and early FJ-3s. The ability to hang the door from the side of the fuselage above the opening was subsequently provided.

Set aside (I think that might be it on top of the wing, end on):

Hung - note the open latches

There were pegs of some sort on the inboard side of the door that could be inserted into "keyholes" on the side of the fuselage.

The keyholes are within the black dots on the side of the fuselage on either side of LTJG Davis' name.

This is a closeup of the keyholes on the FJ-4:

North American General Purpose Attack Weapon (NAGPAW)

In 1954 North American Aviation (NAA) submitted an unsolicited proposal to the U.S. Navy's Bureau of Aeronautics (BuAer) for a single-seat, carrier-based, twin-J46-powered attack airplane for nuclear-weapon delivery in all-weather conditions. It incorporated two unique design features, subsequently patented, one of the first inertial navigation systems and a so-called linear bomb bay, with the store being propelled out of the end of the fuselage along with two empty fuel tanks.

There were several illustrations in the patent (see https://patents.google.com/patent/US2977853). This is the perspective view included:

No NAA-produced three-view drawing or picture of a display model of NAGPAW have been found to my knowledge.  Jens Baganz created a three-view drawing based on the patent illustrations but without the benefit of knowing the basic dimensions of the airplane or the type of engines installed. However, several years ago while doing research at the Washington Navy Yard, I came across a handwritten note that appeared to have been part of a draft summary history of the A3J-1 program created by a historian at BuAer:

It was on the same page as similar data for "NAGPAW II", which matched the numbers for the A3J-1. Note that the thrust of the J46 engine was with afterburning. The length dimension is consistent with the 48-foot long Essex-class carrier elevator albeit a bit short on clearance. I used those dimensions, the patent illustrations, and a J46 three-view drawing along with some assumptions and standard requirements to create a notional three-view drawing.

For the wing planform, I assumed a 35-degree, quarter-chord sweep angle and eyeballed the basic shape. The result had an aspect ratio of 3.18 (seems a little low but acceptable for a tactical jet) and a wing area of 385.5 square feet, which provided a reasonable wing loading. The wing was placed relatively far aft on the fuselage because of the location of the center of gravity on takeoff resulting from the amount of fuel carried in the aft 3/4s of the bomb bay tunnel.

The horizontal tail planform was scaled down from the wing's. It had to be big like the A3J's because of 1) the short moment arm relative to the cg resulting from the aft location of the wing and the shortness of the fuselage necessitated by minimizing the "spot" on a carrier, and 2) the movement of the cg forward when the tunnel fuel tanks were emptied. There was a hint of horizontal tail anhedral in two of the patent illustrations; however, the A3J had none and I'd be in danger of making things up if I tried to justify it from a stability and control standpoint.

The vertical fin seems small given the one-engine-inoperative yaw control power required but its shape was the only element that was consistent among the patent illustrations, plus the NAA proposal for the Navy's 1953 day-fighter competition (won by Vought with what became the F8U Crusader) had a very similar vertical fin.

The width of the mid fuselage was established by the J46 engines separated by a tunnel 36 inches in diameter, which assumed that the bomb was 30.5 inches in diameter consistent with a Mk 8 device (the A3J bomb-train fuel tanks were 30 inches in diameter) repackaged in a downsized Mk 4 configuration. As a check against the length required for the bomb train, I created one with two fuel tanks each sized to hold 275 gallons, the quantity mentioned in the patent. The cross section of the fuselage had to be squared off to accommodate the accessory section located on the lower front end of the J46 as well as provide a well for the main landing gear.

The main landing gear wheel was placed by the required tip-back angle (the takeoff cg having been located with 10% margin relative to the aerodynamic center of the wing) and to provide ground clearance for the aft fuselage at a fairly high angle of attack on landing. The nose wheels (two were assumed to minimize internal volume of the wheel well) were located by having the strut mounted just aft of the ejection seat bulkhead and providing a static nose-up angle consistent with general practice and lining up the tip of the vertical fin and the end of the fuselage, again to minimize overall length for deck parking.

The chord and span of the leading and trailing-edge flaps were just eyeballed. The ailerons look big but my guess was that there was a lot of roll inertia that had to be overcome. The wing-fold line was based on the maximum 27.5-foot width when folded that was standard at the time.

As always, comments, corrections, and additions are welcome.

HUP Pylon Air Inlets

A second pair of air inlets was added to leading edge of the HUP's aft pylon at its intersection with the fuselage after it first entered service in order to increase cooling air to its hard working radial engine mounted in the fuselage. The opening looks like a rounded rectangle from the side but because of the airfoil shape of the pylon cross section and the pylon's interface with the fuselage, it looks very different when viewed from other angles.

For more on the HUP from a modeler's standpoint, see https://tailhooktopics.blogspot.com/2016/04/piasecki-hup-interior.html

1/72 Airmodel AM-1 Mauler

The AM-1's purchased under the original contract (BuNo's 22257-22355), used the Curtiss electric propeller that had cuffed blades and rounded tips.
The aircraft purchased under the subsequent contract (BuNo's 122388-122437) used the Hamilton Standard prop with squared off tips.

The "C" is for NAS Columbus VA-691/ VA-692. Yellow spinners.

Blue Production FJ-2s

The first 14 production FJ-2s (BuNos 131927-40) were completed in the then-standard overall-blue color scheme. Few if any were assigned to operational squadrons. The remainder were delivered as part of the "natural metal" experiment.

BuNo 131927, first production FJ-2

BuNo 131928

BuNo 131937 assigned to Service Test, NATC, Patuxent River

F6F Hellcat wf Torpedo and Frameless Canopy

Note that there was an earlier torpedo trial with an early F6F (note gun barrel fairings and no plywood appurtenances on the torpedo).