Boeing B-38 Conversion Build in 1/72 Scale Part I

Academy began their B-17 line way back in 1988 with a series of early “shark fin” Fortresses, by 1994 they expanded to include B-17E and B-17F kits. These kits have been re-released ever since in a variety of markings and under a number of brands. They have their share of inaccuracies and missing details. Airfix has stepped up and released a late model B-17G which is the best Fort in the scale, but after 40+ years the old Academy kits are in need of replacement. Still, I had this one on hand in the stash and plans for an unorthodox conversion project so it would do.

Essentially an Allison-powered B-17E, the XB-38 was a project developed by engineers at Lockheed-Vega. The ninth production B-17E 41-2401 had been delivered to Lockheed-Vega to help in setting up a Flying Fortress production line at their Burbank, California facility. This was the aircraft modified as the prototype for the XB-38 design. The standard 1,200 hp Wright Cyclone R-1820-65 nine-cylinder radial engines were replaced with Allison V-1710-89 in-lines. Both types of engines were turbocharged to improve performance at altitude. The Allisons each developed 1,425 hp, an increase of 225 hp per engine over the Cyclones. This aircraft is part of my inspiration, at least for the wings.

I have built five Flying fortresses over the years, two Academy and three Airfix. As a result I have accumulated a sizable box of spare parts for Fortresses. Inside are aftermarket sets, bags of unused parts, castings, and masks. To provide the basis for the Allison engines are two sets of Quickboost resin props and nacelles intended for the P-38J Lightning.

Construction begins with the wings, like all builds. I figured it would be best to start here, If I couldn’t adapt the nacelles the project would be over and it would be best to find that out quickly. The B-17s had several inlets under the leading edge of the wings, Academy represents these with engraved lines. Here I have opened up the inlets for the intercoolers (inboard) and superchargers (outboard) for each engine. Missing are the two openings between the engines for the oil coolers which were added for the B-17E and on, an inaccuracy caused by Academy re-using the wings from their earlier shark-fin Fort kits.

Here are the insides of the wings with the intakes boxed in. There is no wheel well detail included in the Academy Fortress kits, the wells are open into the wings. The wells were built up using spare castings from the Airfix B-17G kits and Evergreen stock. You can’t see it in the photo but the landing gear leg is in place on the right wing, it would be very difficult to get it into the bay later with all the extra parts.

Later marks of the Fortress had vent grilles on the upper wing surfaces for fuselage heaters. One of the PE frets in the magic spares box still had a set so I decided to open up the wings and use them.

The resin engine nacelles are of a different cross-section than the kit wing nacelles, the Vega engineers ran into the same problem with their “kit” so I did the same thing they did – fair out the nacelles to match the wings. The bases of these are disks of Evergreen which match the wings glued at the appropriate distance, then the area in between is built up with Evergreen strip and superglue.

The wing openings are all boxed in, wheelwells built up, and the Allison nacelles are in place. The new openings between the engines are for the radiators. The join lines on the nacelles are filled with superglue but they haven’t been sanded smooth at this point. The landing lights are also in place, I fill the seems on those with superglue, file them smooth, and buff them clear again.

The nacelles needed several blending sessions to get them smooth. After each session I sprayed on a coat of Mr. Surfacer 1000 to check for flaws and filled any problem areas, then repeated the process. I still have to restore the panel lines but the wings are done!

Part II here: https://inchhighguy.wordpress.com/2024/01/26/boeing-b-38-conversion-build-in-1-72-scale-part-ii/