One of the most impressive B-17 restoration efforts is that being performed by the Champaign Aviation Museum at Urbana, Ohio. This effort is in the books as B-17G 44-85813 though the decades-long restoration includes parts and pieces of several B-17s. The effort at Urbana was started in 2005 under the inspiration and direction of Jerry Shiffer. Tragically, he was killed in an airplane accident shortly after the project got started, but his family decided to continue to project and now, seventeen years later, there is a B-17, now known as Champaign Lady, sitting in a hangar at Grimes Field at Urbana.
Well, better said that the easily identifiable parts of a B-17 in the hangar are the large fore and aft fuselage sections. The two fuselage sections are essentially complete but remain split at the production break located at station 6 (just aft of the radio room). Less obvious are other components stored around the hangar. This includes horizontal stabilizers, control surfaces, engine nacelles and, not the least of which, wing sections.
I was able to get a recent update on the restoration of Champaign Lady from Dave Shiffer, who graciously spent some time and sent some photos of the work underway as we move into the spring of 2022.
The main work currently underway are on the wing sections. On a B-17, this consists of six airframe components: the inner wing panel, the outer wing panel, and the wing tip…one set for each wing. B-17 wings are currently notable for two reasons: the parts are very scarce and an FAA airworthiness directive (AD) focuses on the wing spar attach points to the fuselage center section.
The effort on restoring the wings for Champaign Lady has been nothing short of amazing. It’s a process that has been underway for over a decade and it is not yet near complete. The right wing inboard section is of particular interest, and I’ll cover that in some detail. But first, the progress of the other five sections should be detailed.
The two wing tips are relatively simple and small assemblies that have been rebuilt and are complete. They are ready for installation.
The two outboard wing sections came from B-17G 44-83722, which has a history of its own that I won’t document here. Suffice it to say that its last utilization was as a nuclear test target in the 1950s and subsequently as a parts source for other B-17s. Those outer wing panels have been disassembled, cleaned, inspected, and repaired as necessary. They are both currently under rebuild and are being reskinned with new aluminum. One of the challenges is the corrugated layer of wing covering that greatly adds to the beefiness of the B-17 wing. Areas of that corrugation have had to be replaced and the museum has been able to custom press new sections for the outer wing panels.
The inner wing panels for the B-17 contain the four engine mounts, the landing gear assemblies, flap attach points, fuel and oil tanks, and all the supporting systems and wiring. Both inner wing panels have come from the original 44-85813. The left wing inner panel is currently undergoing inspection to determine the extent of the work required to bring it to airworthy condition.
The right inner wing panel has been the focus of a decade of work and great progress has been made. The wing was completely disassembled to small component parts. A specialized and highly accurate jig had to be built to hold the wing exactly correct as the parts come back together.
The primary structure of the B-17 inner wing panel consists two truss-type wing spars, forward and rear. Each truss-type spar is built up of of two spar chords, upper and lower, that are assembled with tubular members forming “N” type trusses. The upper and lower spars, both front and rear, are themselves attached to the fuselage center section with steel terminal fittings that are bolted into the inner end of the spar chords. The terminal fittings attach to matching fittings on the fuselage center section and are held together with special tapered pins. Thus, there are four main attach points that hold the wings to the fuselage, along with two other specialized secondary attach points located between the upper and lower spars.
The spar chords were originally manufactured as an extrusion and many smart people have since tried to figure out how exactly this was done back in the 1940s. The challenging feature of the spar chords is that they taper down from the wing root to the length of the section. The taper is both outside and inside the hollow square tubular chord.
The process to extrude these parts in the exact dimensions as required to match the Boeing design is apparently no longer available; that machining capability is long gone. This is why the inner wing sections now so rare…original spar chords are needed to build up a wing and there are few undamaged components available. Trying to re-engineer a new wing spar chord using modern components would require a massive effort and re-certification with the FAA that is not practical. It is left to restorers to use the original Boeing specifications for construction and repairs to the wing structure.
The other problem with the B-17 inner wing is the steel terminal fittings where each of the four spar chords connect to the fuselage center section. Each of the four attachment fittings are slid into the respective spar chords and precisely held in position with eight close-tolerance bolts. It was determined back in 2002 that the spar chords and the steel attachment fittings were subject to cracking around the holes drilled to hold the bolts. This generated an Airworthiness Directive issued by the FAA in 2001 that requires close inspection of these components to find and repair any cracking found. The AD offers several methods of compliance for the inspection, but if cracking is found then repairs are obviously required. The procedure used to repair the cracked components has to be coordinated with and approved by the FAA. (The text and comments on the 2001 AD make for interesting reading, at least for some B-17 aficionados.)
This brings us to the work on the right inner wing panel of Champaign Lady. As part of the rebuilding process of the wing, each of the spar chords were closely inspected both inside and out, with the interior inspection a laborious process of moving a camera along the entire length of the chord checking each surface. The inspection determined that there was cracking in the areas of the steel terminal fittings on three of the four attachment points. These were repaired exactly in accordance with FAA input and Boeing instructions as contained in the AAF Technical Order on Structural Repairs for the B-17G. Essentially, the damaged area was removed and replaced with a new extrusion. The new sections were spliced in with a solid inner core extending as specified beyond each end of the gap, with external plates added fore and aft to the spar chord. Holes were carefully drilled and bolts added to hold the entire assembly together.
That work is completed on the right inner panel as the truss spars were assembled in the jig. In the past months, the ribs and stiffeners have been assembled and at this time the nose ribs are being attached to form the leading edge of the wing. Interior fittings to hold the fuel tanks and other components have been assembled. The engine nacelles for number three and four engines were completed separately and are ready to be added to the wing panel at the appropriate time. The major assembly to attach the right main landing gear has been fitted into the area aft of where the number three nacelle will be installed.
As can be seen from the photos, building up a B-17 wing is not an easy task and it has taken many years of dedicated work by a talented team to bring it to this point. It goes without saying the Champaign Lady wing team has become expert on repairing the spar chords and terminal fittings. Good thing, as an inspection of the left inner wing panel has revealed that at least one of the four spar chords and terminal fittings will also require the same repair.
Anyone wanting to look at some detail of the restoration process can do a search on the terms “Champaign Lady B-17” on You Tube. There are a variety of short videos, such as this one, that document different phases of the rebuilding effort. Also, be sure and check out the Champaign Aviation Museum website. Donations to the effort are cheerfully accepted, by the way, as detailed on the website.
And, finally, I again would be remiss if I did not mention that the complete story of B-17G 44-85813 is told in words and pictures, along with the other 47 surviving B-17s, along with the story of the post-war use of the B-17 in civil and military service, can be found in Final Cut: The Post-War B-17 Flying Fortress and Survivors.