B-17 Grounding Expected

From Avweb:

"As expected, the FAA has issued an AD that likely requires a complex inspection of the wing attachment assemblies on all the airworthy aircraft. The FAA says an eddy current inspection of bolt holes in the wing structure is likely the most efficient method and will take about 25 hours. If issues are found repairs will have to be done and that might be expensive.

The FAA was notified when a pilot on a walkaround noticed that the left wing on a B-17 he was getting ready to fly had a two-inch gap between it and the fuselage. "This AD was prompted by a report indicating that the left front spar lower fitting had completely separated at the wing-to-fuselage joint, and the equivalent joint on the right side of the airplane was cracked," the AD says. "This AD requires inspections of the wing terminal-to-spar chord joints, and repair if necessary."

What I find concerning about that AD is that it applies to experimental aeroplanes, not just certified ones.
In the past the FAA have worded AD very strongly to imply compliance is mandatory, however this is the first I have seen that is actually mandatory.
I hope this doesn't introduce a precedent that all experimentals now become susceptible to ADs.