Ordnancement loading a 1000 pound General Purpose bomb onto an SBD-5 Dauntless during the Pacific campaign. This image clearly illustrates the 'wishbone' for the bomb displacement mechanism which pivots to sling the bomb outside the SBD's propeller arc during the dive. Note the hinge where the wishbone pivots. This mounts to a sturdy internal web structure which straddles the wing center section. Note also the two rectangular portals just in front of the wheel well. The larger of these is the terminus for the chute which sheds empty shell casings from the righthand, forward-mounted .50-calibre machine gun. The smaller portal expels discarded ammunition links. There is another set of these chutes on either side of the airframe for the lefthand machine gun. Furthermore, the light-colored cable hanging down from the top of the image is a grounding wire, likely clamped to the exhaust pipe. Grounding the aircraft to the ship during refueling or loading ordnance helps reduce the possibility of static electrical discharges which could prove calamitous, for obvious reasons. (US Navy image)
Ordnancement loading a 1000 pound General Purpose bomb onto an SBD-5 Dauntless during the Pacific campaign. This image clearly illustrates the 'wishbone' for the bomb displacement mechanism which pivots to sling the bomb outside the SBD's propeller arc during the dive. Note the hinge where the wishbone pivots. This mounts to a sturdy internal web structure which straddles the wing center section. Note also the two rectangular portals just in front of the wheel well. The larger of these is the terminus for the chute which sheds empty shell casings from the righthand, forward-mounted .50-calibre machine gun. The smaller portal expels discarded ammunition links. There is another set of these chutes on either side of the airframe for the lefthand machine gun. Furthermore, the light-colored cable hanging down from the top of the image is a grounding wire, likely clamped to the exhaust pipe. Grounding the aircraft to the ship during refueling or loading ordnance helps reduce the possibility of static electrical discharges which could prove calamitous, for obvious reasons. (US Navy image)

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.

An illustration from the SBD's Illustrated Parts Manual which shows the two web assemblies which form the internal support structure for the Bomb Displacement Gear. As the image reveals, thes subassemblies buttress fuselage Frame #1, which also doubles as the engine firewall.
An illustration from the SBD's Illustrated Parts Manual which shows the two web assemblies which form the internal support structure for the Bomb Displacement Gear. As the image reveals, thes subassemblies buttress fuselage Frame #1, which also doubles as the engine firewall.

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.

An illustration from the SBD's Structural Repair Manual which shows the bomb-aiming window fitted between the rudder pedal troughs. The window lies between the two support web assemblies for the Bomb Displacement Gear. Note, this window was sometimes faired over as it was difficult to see through at the best of times, and was easily mired in engine oil and dirt.
An illustration from the SBD's Structural Repair Manual which shows the bomb-aiming window fitted between the rudder pedal troughs. The window lies between the two support web assemblies for the Bomb Displacement Gear. Note, this window was sometimes faired over as it was difficult to see through at the best of times, and was easily mired in engine oil and dirt.

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 original righthand web assembly which formed part of the internal support structure for B-22's Bomb Displacing Gear. Several components from this subassembly proved to be salvageable. For reference, the forward edge which mounts to Frame #1 lies at the right side of this photograph, while the bottom edge mates with the lower fuselage skin. (image via Pioneer Aero Ltd.)
The original righthand web assembly which formed part of the internal support structure for B-22's Bomb Displacing Gear. Several components from this subassembly proved to be salvageable. For reference, the forward edge which mounts to Frame #1 lies at the right side of this photograph, while the bottom edge mates with the lower fuselage skin. (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.

An illustration of the SBD's righthand fixed forward machine gun setup showing the chutes for the spent shell casings and ammunition links. The former is seen running behind the ammunition can, while the latter passes in front of it.
An illustration of the SBD's righthand fixed forward machine gun setup showing the chutes for the spent shell casings and ammunition links. The former is seen running behind the ammunition can, while the latter passes in front of it.
A wartime image showing US Navy crewmen reloading the ammunition can for an SBD's righthand forward-firing machine gun. Note the two rectangular openings in the fuselage just beside the propeller tip. These are the ejection ports for the spent shell casings and ammunition links.
A wartime image showing US Navy crewmen reloading the ammunition can for an SBD's righthand forward-firing machine gun. Note the two rectangular openings in the fuselage just beside the propeller tip. These are the ejection ports for the spent shell casings and ammunition links.