
Bomb Displacing Gear:
Outside of its perforated dive flaps, one of the SBD’s most defining features is the mechanism which allows it to safely deploy its centrally-mounted 1,000 lb bomb during a steep dive. This large, wishbone-shaped yoke assembly, connects to either side of the bomb at one end and a forged-steel, fuselage-mounted hinge at the other, as shown in the image above. Referred to formally as the Bomb Displacing Gear, this equipment is designed to pivot the bomb away from the SBD’s propeller arc upon release, while also ensuring that the weapon maintains an accurate plunge towards the target. The hinge, of course, has to mount against a sturdy internal support. And this comes in the form of two parallel web assemblies which extend 22 inches from the aft side of fuselage Frame #1 (Station 0) to the bulkhead at Frame #2 (Station 22), as the illustration below describes.

Interestingly, these web assemblies serve several other duties. For instance, the forward flanges help support the firewall at Frame #1, while the bottom flanges help shape the lower fuselage between the wing leading edges. They also feature the bomb aiming window which sits between the pilot’s feet, while the lower attachment points for the brake master cylinders mount to them as well.

Restoring the Displacing Gear Support Assemblies:
Pioneer Aero’s Hadon Smith recently began working on these web assemblies. While much of the original structure in B-22 was crushed during the aircraft’s wartime crash, Smith was able to salvage several restorable components from the righthand example. He has since refabricated most of the missing parts for these assemblies and begun trial-fitting everything together.

The salvageable components from B-22's righthand bomb displacing gear support web. They have been bead-blasted and inspected and are all airworthy. Note, the forging at lower right attaches the web assembly to the firewall, while the "T" extrusion (top) runs along the web’s upper edge. The two small components are stiffeners. (image via Pioneer Aero Ltd.)
The two web assemblies (righthand lying flat) which support the Bomb Displacing Gear are seen here during their restoration. Both assemblies have their outboard face in view. Everything seen here is of new manufacture, with the exception of the parts shown in the previous image. Of note, the bottom flange for each web assembly has a slight curve in it to match the lower fuselage contour; forming blocks were required to create that shape. (image via Pioneer Aero Ltd.)
Spent Ammunition Casing Disposal:
As most readers will know, the SBD features a pair of fixed-position, .50-calibre machine guns in the forward fuselage. When fired, these two weapons discharge their spent shell casings and ammunition links via separate chutes which drop down through the airframe and out the bottom on either side of the fuselage. As it happens, the chutes for the spent shell casings actually pass through the inboard wing leading edges, so Hadon Smith recently cut into those freshly-rebuilt structures to fashion the appropriate portals. The following images reveal the work he has so far achieved in that task on the righthand inboard leading edge.

The righthand leading edge for the SBD’s wing center section. The ammunition case ejection chute for the righthand fixed gun passes through either side of the leading edge skin in the area shown here. At the time this image was captured, Hadon Smith had marked out the sections which needed cutting away and also drilled holes for the externally-mounted doubler for stiffening the structure. (image via Pioneer Aero Ltd.)
This image shows the righthand leading edge after Hadon Smith had cut out the upper and lower openings for the spent shell casing ejection chute. (image via Pioneer Aero Ltd.)
This image shows the skin-doubler for the spent shell casing ejection chute (perfectly shaped to conform to the leading edge contour) drilled and clecoed against the righthand leading edge. All that remains is to primer-paint the doubler and rivet it in to the structure. Smith will follow the same process for the shell chute openings in the lefthand inboard wing leading edge as well. (image via Pioneer Aero Ltd.)
