FAA grounds all B-17E,F, & G models

[Bob Womack]

Going with what I've heard from the B-17 group on Facebook: This isn't a wing spar issue, it is a wing attachment issue. Apparently the EAA's Aluminum Overcast was discovered to have a two-inch gap between the port wing and root while out on tour! To find the problem they had to disassemble the plane and ship it home. They told the FAA what they discovered and the FAA issued an Advanced Directive for the rest of the survivors involving disassembly, advance imaging, and remediation if necessary. It isn't a hard inspection.



These are the parts in question, forward mounting plates and pins. The arrows point out where the pieces were relieved at service depots when they wouldn't reassemble after a service. Apparently one side had to be heated and the other had to be frozen before it could be done and some service depots didnt' know so the parts griped too much to be reassembled. The result over time could be hidden fracturing leading to the wings becoming loose! The parts aren't hard to find or fabricate. Aluminum Overcast and Sentimental Journey have been inspected and are back in the air already. Others are completing the process right now. The directive indicates that this may end up being a recurring 120 mo/2500hr inspection cycle for B-17s. More, HERE.

Bob

Information

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[GeeRam]

Going with what I've heard from the B-17 group on Facebook: This isn't a wing spar issue, it is a wing attachment issue. Apparently the EAA's Aluminum Overcast was discovered to have a two-inch gap between the port wing and root while out on tour! To find the problem they had to disassemble the plane and ship it home. They told the FAA what they discovered and the FAA issued an Advanced Directive for the rest of the survivors involving disassembly, advance imaging, and remediation if necessary. It isn't a hard inspection.

https://www.milsurps.com/images/impo...71269566-1.jpg

These are the parts in question, forward mounting plates and pins. The arrows point out where the pieces were relieved at service depots when they wouldn't reassemble after a service. Apparently one side had to be heated and the other had to be frozen before it could be done and some service depots didnt' know so the parts griped too much to be reassembled. The result over time could be hidden fracturing leading to the wings becoming loose! The parts aren't hard to find or fabricate. Aluminum Overcast and Sentimental Journey have been inspected and are back in the air already. Others are completing the process right now. The directive indicates that this may end up being a recurring 120 mo/2500hr inspection cycle for B-17s. More, HERE.

Bob

Those items in the photo posted are the items related to the previous AD issued back in 2001.

The new AD is in relation to the bolts that fix through the steel spigot that fits inside the tapered alloy spar tube, the end of this spigot is what attaches to those steel plates.

This updated article from aerovintage shows photo's from the items in a current dismantled B-17 being restored.

https://www.aerovintage.com/2023/05/...e-may-25-2023/

The big potential problem, will be if any NDT shows up any corrosion or cracks in the tapered ally tube section, rather than the steel spigot, as its impossible to reproduce these tapered spar tubes.
The steel spigot can be replaced, although to do so means taking the wings off.