Yankee Lady grounded out of caution; New AD coming?

[aerovin2]

Out in the ether this morning: Yankee Air Museum has grounded B-17G Yankee Lady, expecting a new FAA AD concerning wing attach structure and/or wing spars. No actual FAA info yet.

I added a post to my website with an overview: https://www.aerovintage.com/2023/04/15 ... 3cb9247832

[terveurn]

So back to square one

There is a shortage of inners

There is a problem with the attachment points

The next obvious solution is new build spars (which would need new technology to rediscover the lost process).

Now the question is what hoops would the FAA need to certify new spars (and it can be done; the BoB Lancaster was respared, majority of the Hurricanes flyable have new spars, same with the Spitfires [the original wartime spitfire alloys delaminated])

[aerovin2]

So, why build new spar caps if the problem is the fuselage attach points?

[terveurn]

So, why build new spar caps if the problem is the fuselage attach points?

Could be a hole raft of problems; age limited parts, dissimular metal corrosion, elongation of the fittings, the FAA being the FAA.

Have to read the AD to see what they are addressing, but being a 65-year old aircraft could just be time (plus not a single B-17 flyable has accurate MX records [Military plus Civil])

[Sparks61]

Out in the ether this morning: Yankee Air Museum has grounded B-17G Yankee Lady, expecting a new FAA AD concerning wing attach structure and/or wing spars. No actual FAA info yet.

I added a post to my website with an overview: https://www.aerovintage.com/2023/04/15 ... 3cb9247832

Thanks for the informative post, Scott. You cover the issue much more clearly and succinctly than some of the other sources I'm reading. One question: what's the source of the diagrams that illustrate your post? I'd enjoy finding a copy of that book, if indeed it is from a book.

Thanks!