Below are the links to Adobe Acrobat files of the Airworthiness Concern Sheet concerning the Beech 18 spar inspection.  It is my understanding that this is not yet an NPRM (notice of proposed rulemaking) for the AD, but the FAA (Gary Park) is looking for feedback prior to the the issuance of an NPRM.

The email address and phone number for Gary Park is listed in some of the files below.  PLEASE READ AND UNDERSTAND THE PROPOSED AD PRIOR TO COMMENTING TO THE FAA.  The spar strap and x-ray is always a heated topic with many different opinions.  Comments should be made after much consideration via email and contact information should be included.

Some browsers can open these files directly.  If you want to save them on your computer, right click on the file and click "save target as" or "save link as"

Airworthiness Concern Sheet - Beech 18 Spar

Beech 18 Document of proposed AD - (large file - 4mb) this is the main proposal from the FAA.

Airworthiness Concern Sheet Guide - This is the guide from the FAA website on what an airworthiness concern is and how it is handled. 

 Appendix K - Spar Problems - From the book:  Beech 18: A Civil & Military History by Robert Parmerter 2004