----[Please read http://ercoupers.com/disclaimer.htm before following any advice in this forum.]---- _____________________________________________________________ Part 2 Hi: I talked to Andy Working (?), AOPA last Friday morning. He will call later in the week. We, AOPA and I, need to develop engineering data and service history of the problem to present a case to the FAA. My plan is to review the Service Bulletin No. 31, dated January 29, 2002, to determine if the drawings are in compliance with the FAA certification requirements. That is, if there is adequate information on the drawings to manufacture the parts and an analysis to support cutting the four inspections holes on each side of the center line of the fuselage. My preliminary analysis showed a negative margin of safety. My calculations were based on the copy of the Service Bulletin published in Coupe Capers. Perhaps the FAA engineer notified Univair of my comments that there was inadequate data in the original version of the SB. And that is the reason I need a copy of the Service Bulletin referenced in the AD. I have not found a copy of the e-mail I sent to the FAA engineer informing him the Service Bulletin was inadequate to make the parts. Also I told the FAA engineer that the way the service bulletin was written it forced everyone to buy the parts from Univair. It use to be that the FAA could not endorse sale of parts from a manufacturer. You should be able to contact the knowledgeable members to get maintenance support for the compliance of Univair's service bulletin, or for an alternate means of compliance. The FAA will not consider "hand waving" means of an alternate inspection. Gene [EMAIL PROTECTED] _____________________________________________________________ Skip: I just finished talking with a Univair representative. Univair has not issued SB 31. They are waiting on FAA's inputs and approval. I asked how could FAA reference the SB in their NPRM when it has not been approved and is not available to coupe owners in order for them to comment on. Something is not normal here. As an ex-writer of ADs and service bulletins I find this subject very unusual. How can the public comment on an AD, which includes a company service bulletin that is not yet available to the public? This situation should be brought to the attention of AOPA, EAA, and other alphabet groups. My next step is to contact the FAA. Gene _____________________________________________________________ Hi Mark: Are you still a DER for Univair? I called them this morning to get a copy of their Service Bulletin No. 31. The Rep. told me that the FAA has not approved the SB, nor has told them anything about it. My main question is: How can FAA reference a company service bulletin in a proposed AD without having approved the SB? And if it is not approved, how can the public comment on it? I am ready to contact the FAA in the Denver ACO, but I no longer have a name for the person in charge. Perhaps you can provide the name. I would ask FAA the above two questions. Are you planning on attending the Coupe Round Up in Michigan? My home state. Best regards, Gene _____________________________________________________________ Skip: I tried sending an e-mail to my old ex-FAA buddy Mark Baldwin in Denver. The e-mail address in the EOC Directory is apparently wrong. Can you check and send me the correct address? Mark is, or least was, an FAA DER working for Univair. Gene _____________________________________________________________ Skip: Since I have had no feed back from you, I have submitted my comments to the FAA regarding the subject NPRM AD. My main point being: How can the FAA expect anyone to furnish meaningful comments when they have not approved Univair's Service Bulletin No. 31? After all, the FAA says to comply with the procedures in the SB. A copy of my comments/questions is attached for your information. Gene Turner Aircraft, Inc./Cavu Publishing Co. P.O. Box 74 Cleburne, Texas 76033-0074 Phone: (817) 556-3535 Fax: (817) 556-3535 <mailto:[EMAIL PROTECTED]> [EMAIL PROTECTED] www.turner-t40-books.com April 24, 2002 FAA Central Region Office of the Regional Counsel Attention: Rules Docket No. 2001-CE-45-AD 901 Locus, Room 506 Kansas City, MO 64106 Subject: Comments on NPRM regarding Rules Document No. 2001-CE-45-AD, applying to Univair Aircraft Corporation Alon A-2, etc. To Whom It May Concern: I have reviewed the Rules Document No. 2001-CE-45-AD, as published in the Federal Register, Volume 67, No. 64, dated April 3, 2002, and offer the following comments and/or questions for your consideration: 1. The proposal states that compliance must be done in accordance with procedures contained in Univair's Service Bulletin No. 31. On April 23, 2002 I telephoned Univair to obtain a copy of the service bulletin. The Univair representative told me that the FAA had not approved the service bulletin, and that they (Univair) did not know what the FAA was doing. Now the question: How does the FAA expect anyone to intelligently comment on this proposed rule change without knowing what the service bulletin contains? 2. Based on the copy of the Service Bulletin No. 31, dated July 24, 2000, published by the Ercoupe Owners Club (EOC) in "Coupe Capers", dated November 2001, I submit the following comments: A. Drawing No. SB-31, dated 04-09-00, does not contain adequate information, as required by the Code of Federal Regulations, (CFR) Part 21.31(b), and Part 45.14 i.e. Type of material and specification, thickness of material, dimensional tolerances, finish specification, and marking of parts are not called out. B. Based on the dimension shown, and assuming the airplane's bottom fuselage skins are only 0.020 inches thick and the material is 2024T-3 aluminum allow, a simplified stress analysis shows that the reinforcement rings and attaching rivets have negative Margins of Safety (MS). Using the lost material theory, since the actual airplane design loads are not available, the analysis is; Cutout (lost material): 4.0 x 0.020 = 0.080 inches squared (4.0 in. diameter cutout) Width of reinforcement ring: 1.0 in. Material width added: 2.0 in. Area of material added: 0.020 x 2 = 0.040 sq. in Not considering the type of material used, one can see that only 50% of the area of the cutout area has been replaced. MS = 2/4 - 1 = 0.5 - 1 = Negative 0.5 x 100 = -50%. This Margin applies regardless of the thickness of materials used. In addition: The allowable load that a 4.0 in strip, 0.020 in thick, of 2024T-3 can carry is: 0.080 x 53,000 psi (Ref. Mil-Hnbk 5-e) = 4200 lbs. The allowable of seven MS2047AD-3 rivets = 7 x 207 (Ref. Airplane Structures by Niles & Newell, Vol. 1, Table 11:1, page 362) = 1449 lbs. MS = 1449/4200 - 1= Negative 0.66 x 100 = -66%. Unless the service bulletin has been changed lately, it is structurally inadequate and does not comply with the FAA certification regulations. Incidentally, I submitted the similar information to FAA Engineer Roger Caldwell, in Denver, after he sent the FAA Airworthiness Concern Sheet, dated October 25,2001, to the EOC. I did not receive any acknowledgment. When Univair Service Bulletin No. 31 is approved by the FAA and distributed by Univair, I will continue my review of it and will submit comments as appropriate. Sincerely, [signed] Eugene L. Turner President and Chief Engineer Alon A-2 Owner ==^================================================================
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