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B-17 AD Update: May 25, 2023

B-17 AD Update: May 25, 2023

A couple of developments have occurred since the FAA Airworthiness Directive (AD) was released on May 17. (The AD becomes effective on June 1.)

First, not surprisingly, the B-17 Preservation Group that operates B-17G 44-85784, otherwise known as Sally-B, from Duxford in England announce that it is self-grounding the B-17 pending consideration of the FAA AD. The statement from Elly Sallingboe, dated May 23, reads:

“After careful consideration it has now been decided to ground our beloved B-17 until the ongoing wing spar issue is sorted. As I write this, we are working flat out to complete this difficult task, helped by our devoted team and many friends. Thank you IWM Duxford for giving us space in the AirSpace Hangar to carry out the required work. More news will follow shortly.”

Jump to the B-17 Preservation news page on its website for the most current information.

Second, the Airbase Arizona of the Commemorative Air Force (CAF), operator of B-17G 44-83514, otherwise known as Sentimental Journey, performed an inspection of the innermost bolt and bolt holes on the forward lower spar chord to terminal fitting on both right and left wings. No cracks or corrosion were detected, and the parts were reassembled. However, the applicable part of the AD reads as follows:

“(2) On the left and right lower forward terminal fitting-to-spar chord joint assemblies, remove the most inboard fastener common to the spar cord and the terminal fitting, and do an eddy current bolt hole inspection on the steel terminal fittings and on the aluminum spar chord in accordance with procedures approved by the Manager, West Certification Branch, FAA.”

Thus, even though an inspection was completed and no cracks or corrosion were found, the FAA must approve the inspection procedure used to comply with the AD, or at least that is the current interpretation of the AD by the operator of this B-17.

This has put a hold on launching Sentimental Journey on the CAF summer tour. As can be seen with the CAF published schedule online, the first two tour stops…Albuquerque and Fort Collins-Loveland… have had the B-17 dropped from the visits, leaving just the CAF B-25. It is hoped that the AD process will be completed in time for Sentimental Journey to pick up the tour at Rock Springs (Wyoming) on June 6. The tour schedule will an obvious clue that the AD has been met, so watch and wait.

No word yet on any action yet taken on the other two flying B-17s, 44-8543, otherwise known as Ye Olde Pub, and 44-85829, otherwise known as Yankee Lady. However, Ye Olde Pub was parked on the Erickson Aircraft Collection ramp on May 24, with no activity being directed its way.

Finally, I had the opportunity to take a close look at the two parts affected by the AD when I had occasion to visit the restoration hangar for 44-85790, otherwise known as Lacey Lady, on May 23. I thought it might be of interest to see these two components up closer. (Note that I am not an A&P mechanic nor expert on this structure; however, I have closely read the AD and spoken with several operators of these aircraft.)

This is the forward lower spar chord tube at the inboard end of the left wing. The spar chord is made from an aluminum alloy. The hole indicated by the arrow holds the bolt that must be removed for inspection as one method to comply with the FAA AD. After the bolt is removed, an eddy current bolt hole inspection is performed on the steel terminal fittings and on the aluminum spar chord. This bolt is difficult to reach in an assembled airplane; some wing supporting structure has to be removed to provide access. However, that work is much easier than removing the wings and inspecting the whole assembly, which is the other method that can be used to comply with the AD,
This is the a lower wing terminal fitting. The fitting is made of steel. The left side of the fitting in this photo slides into the spar chord tube and is held in place with eight close-tolerance bolts. The inner hole and bolt, as indicated by the arrow, is the one that is to be inspected for AD compliance. The alternative method is to remove the entire terminal fitting from the spar cord for inspection, a method that requires the wings to be off the airplane. In this photo, the three large holes on the right side of the fitting sandwich into the wing attach assembly on the fuselage and are held with tapered pins with castle nuts securing them.