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Having drilled out the attaching rivets, Craig Cunha (left) and Stephen Fox (right) begin lifting the trailing edge spar (No.5) from the SBD's wing center section. (image via Pioneer Aero Ltd.)

Spar Removal:

Recently, Pioneer Aero’s engineers successfully trial-fitted the newly-manufactured wing center section skins which mate up with the rear spar (Spar No.5) on its upper and lower surfaces. With these skins now aligned properly with the rivet holes on Spar No.5, the team was free to remove this structural member and commence its restoration. Drilling off the remaining rivets attaching the spar to the center section, Craig Cunha and Stephen Fox were able to lift it from the airframe, being careful not to snag this 11’ wide component on any intersecting structure.

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Craig Cunha (left) and Stephen Fox (right) lifting Spar No.5 clear of the SBD's wing center section. They had to proceed carefully to ensure it cleared the structure still mounted to the wing. Note that the lower halves for fuselage Frame #7 are still riveted to the spar. (image via Pioneer Aero Ltd.)

Restoring Spar No.5:

Cunha and Fox completely disassembled Spar No.5 into its component parts, bead-blasting then inspecting each item regarding its potential future serviceability. Readers may recall that the lower half of the SBD’s fuselage is built integrally with the wing center section. It just so happens that the lower halves of Frame #7 are riveted to Spar No.5, so these parts were amongst those receiving treatment.

While the spar web, end channels and lower spar cap were too corroded for reuse, Cunha soon got to work fabricating their replacements. Thankfully, the other parts, including the lower halves of fuselage Frame #7, were all reusable and each of these has since undergone restoration to airworthy condition.

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A closeup view showing where the lower end of fuselage Frame #7 attaches to the forward face of Spar No.5. Note how most rivets are showing their bucked ‘tails’ with just the topmost and lowest rows being head-side up. While it may seem unusual to shoot rivets from different directions like this, ease of installation is often the reason behind it. (image via Pioneer Aero Ltd.)
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Another view of the original Spar No.5 (on left) pictured with the remanufactured example (featuring an original upper spar cap) on the right. (image via Pioneer Aero Ltd.)
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The fully-refurbished lower sections of Frame #7 following their restoration. (image via Pioneer Aero Ltd.)