Overview:

As reported in Restoration Update #90, Pioneer Aero has made significant progress in rebuilding the SBD's lower forward fuselage. We are happy to reveal that the upper forward fuselage has received similar attention too. Pioneer's William Lowen recently began trial-fitting the structure between Fuselage Frames #1 and #2 in the SBD's Upper Fuselage jig. To show just how far they have come such a short time, it is worth reflecting back on how B-22's Fuselage Frame #1 looked prior to Pioneer splitting the aircraft apart for rebuild in the summer of 2023. The image below provides an excellent depiction of the sorry state which Fuselage Frame #1 was in at the time.

This image shows the ragged condition of the airframe's forward bulkhead (Fuselage Frame #1) in the summer of 2023. The impact damage and corrosion rendered all of Fuselage Frame #1's larger components beyond airworthy repair, and many of the smaller ones too. Note that the upper engine bearer attachment mounts are just outboard of the U-shaped cutouts (for the machine guns) at the top. The lower attachment mounts, of course, were torn off during the crash. (photo via Pioneer Aero Ltd.)
This image shows the ragged condition of the airframe's forward bulkhead (Fuselage Frame #1) in the summer of 2023. The impact damage and corrosion rendered all of Fuselage Frame #1's larger components beyond airworthy repair, and many of the smaller ones too. Note that the upper engine bearer attachment mounts are just outboard of the U-shaped cutouts (for the machine guns) at the top. The lower attachment mounts, of course, were torn off during the crash. (photo via Pioneer Aero Ltd.)

Fuselage Frame #1 (Upper Section):

As noted in previous articles, Fuselage Frame #1 is the SBD's forward-most fuselage bulkhead. It comprises three main parts—upper, middle and lower—with the latter two components being integrated within the SBD's Wing Center Section subassembly. By contrast, the topmost section of Fuselage Frame #1 forms part of the Upper Fuselage subassembly. It is riveted to the lower sections only when the Upper Fuselage is mated with the Wing Center Section.

The main components from B-22's Fuselage Frame #1 were too badly damaged to resurrect for an airworthy rebuild, as the above image illustrates, so William Lowen remanufactured what was needed. The upper section returned from heat treatment some time ago but, more recently, Lowen began marking off and drilling out the numerous holes across its face. He also refabricated the steel doublers which frame the engine bearer lugs on Fuselage Frame #1, then drilled and reamed them to match.

The image below shows the frame being trial-fitted; its caption describing the purpose behind some of the more prominent holes cut into it.

A view showing the top section of Fuselage Frame #1 being trial-fitted into the SBD’s upper fuselage jig. Most of its holes marked and drilled. The big bolts in the upper corners of the jig plate are where the engine bearer bolts will pass through. These two points, along with the horizontal reference line between them (scribed into the jig plate) serve as datums for the front upper half of the fuselage. While much of Fuselage Frame #1 is obscured by the jig plate in this image, we can see two U-shaped cutouts along its top edge. These are where the forward firing machine guns pass through the frame, while the rectangular holes just to their outside edges accommodate the chutes which channel discarded ammunition belt links out of the airframe when the guns fire. The big round hole in the middle of the frame provides warm air to the cockpit for de-misting the windows when necessary, while the long slot to its left provides space for engine instrument sensor lines. (image via Pioneer Aero Ltd.)
A view showing the top section of Fuselage Frame #1 being trial-fitted into the SBD’s upper fuselage jig. Most of its holes marked and drilled. The big bolts in the upper corners of the jig plate are where the engine bearer bolts will pass through. These two points, along with the horizontal reference line between them (scribed into the jig plate) serve as datums for the front upper half of the fuselage. While much of Fuselage Frame #1 is obscured by the jig plate in this image, we can see two U-shaped cutouts along its top edge. These are where the forward firing machine guns pass through the frame, while the rectangular holes just to their outside edges accommodate the chutes which channel discarded ammunition belt links out of the airframe when the guns fire. The big round hole in the middle of the frame provides warm air to the cockpit for de-misting the windows when necessary, while the long slot to its left provides space for engine instrument sensor lines. (image via Pioneer Aero Ltd.)

Structure Between Fuselage Frames #1 & #2:

Will Lowen mounted the newly-fabricated Fuselage Frame #1 into the jig, replacing the damaged original he had used earlier this year (see Update #74) to transfer rivet holes to any newly-made interconnecting components where needed. With the new frame in place, Lowen then trial-fitted all of the structure linking it to Frame #2, and began the process of drilling it off where necessary. The parts were undergoing trial-fitting at the same time since they all have influences over each other.

Most of this structure is part of the forward cockpit and/or associated with supporting the two .50 calibre forward-firing machine guns. Furthermore, it comprises a mixture of original pars from B-22 and donor airframes, along with newly-made replacement parts. While this has made the process of matching rivet holes between parts from different aircraft quite challenging in places, the team has made excellent progress as the following images reveal.

A view of the structure which links Fuselage Frames #1 & #2 during the trial-fitting process. Pretty much all of the primer-painted parts in this image are restored original components, either from B-22 or a donor airframe, whilst those in bare aluminum are of new manufacture. The replacement lefthand engine bearer fitting is seen temporarily attached to the forward end of the upper longeron. The lefthand rib (painted in primer) is a restored original part from a donor aircraft, while its righthand counterpart is newly-made (although the painted channels, both top and bottom, are restored originals from a donor airframe). The primer-painted forward mounting block for the lefthand machine gun is an original B-22 part. Assembling a mixture of original, donor and replacement components can be challenging since the existing rivets hole do not always line up exactly! (image via Pioneer Aero Ltd.)
A view of the structure which links Fuselage Frames #1 & #2 during the trial-fitting process. Pretty much all of the primer-painted parts in this image are restored original components, either from B-22 or a donor airframe, whilst those in bare aluminum are of new manufacture. The replacement lefthand engine bearer fitting is seen temporarily attached to the forward end of the upper longeron. The lefthand rib (painted in primer) is a restored original part from a donor aircraft, while its righthand counterpart is newly-made (although the painted channels, both top and bottom, are restored originals from a donor airframe). The primer-painted forward mounting block for the lefthand machine gun is an original B-22 part. Assembling a mixture of original, donor and replacement components can be challenging since the existing rivets hole do not always line up exactly! (image via Pioneer Aero Ltd.)

A righthand view of the structure depicted in the previous image. As before, pretty much all of the primer-painted parts in this image are restored original components, either from B-22 or a donor airframe, whilst those in bare aluminum are of new manufacture. Although partially obscured by a c-clamp towards the right of the image, we can see the replacement righthand engine bearer fitting in the process of being fitted to the upper righthand longeron and Fuselage Frame #1. The forward end of the righthand rib and machine gun mounting block are also being positioned against Fuselage Frame #1. (image via Pioneer Aero Ltd.)

An interior view of the SBD’s forward upper fuselage looking at the lefthand aft face of Fuselage Frame #1. Note the primer-painted mounting block for the lefthand machine gun sitting between replacement channels is an original B-22 component. Also note the extruded stiffener attached horizontally to the rear face of Fuselage Frame #1. Newly made, it passes through the machine gun mounting blocks, so drilling it off against the fuselage frame required care to be sure the proper clearances were maintained. (image via Pioneer Aero Ltd.)