# Airworthiness Directives: Fairchild Aircraft Models SA227-AC and SA227-AT Airplanes > Briefs, arguments, decisions, and more. URL: https://www.frixlaw.com/law-library/documents/fr%3A94-7497 ## Record - **Collection:** Federal Register - **Document type:** Uncategorized Document - **Published:** March 30, 1994 ## Text DEPARTMENT OF TRANSPORTATION 14 CFR Part 39 [Docket No. 91-CE-12-AD] Airworthiness Directives: Fairchild Aircraft Models SA227-AC and SA227-AT Airplanes AGENCY: Federal Aviation Administration, DOT. ACTION: Notice of proposed rulemaking (NPRM). ----------------------------------------------------------------------- SUMMARY: This document proposes to supersede Airworthiness Directive (AD) 83-12-01, which currently requires repetitively inspecting the lower wing skin panel for cracks on certain Fairchild Models SA227-AC and SA227-AT airplanes, and installing wing skin reinforcement doublers if any wing skin crack is found. The Federal Aviation Administration's policy on aging commuter-class aircraft is to eliminate or, in certain instances, reduce the number of certain repetitive short-interval inspections when improved parts or modifications are available. The proposed action would require installing wing skin reinforcement doublers or wing skin stringer ties as terminating action for the repetitive inspections that are currently required by AD 83-12-01. The actions specified in the proposed AD are intended to prevent fatigue failure of the lower wing skin panels, which could result in loss of control of the airplane. DATES: Comments must be received on or before June 10, 1994. ADDRESSES: Submit comments in triplicate to the Federal Aviation Administration (FAA), Central Region, Office of the Assistant Chief Counsel, Attention: Rules Docket No. 91-CE-12-AD, Room 1558, 601 E. 12th Street, Kansas City, Missouri 64106. Comments may be inspected at this location between 8 a.m. and 4 p.m., Monday through Friday, holidays excepted. Service information that applies to the proposed AD may be obtained from Fairchild Aircraft, P.O. Box 790490, San Antonio, Texas 78279- 0490; telephone (210) 824-9421. This information also may be examined at the Rules Docket at the address above. FOR FURTHER INFORMATION CONTACT: Mr. Hung Viet Nguyen, Aerospace Engineer, FAA, Airplane Certification Office, 2601 Meacham Boulevard, Fort Worth, Texas 76137-0150; telephone (817) 222-5150; facsimile (817) 222-5959. SUPPLEMENTARY INFORMATION: Comments Invited Interested persons are invited to participate in the making of the proposed rule by submitting such written data, views, or arguments as they may desire. Communications should identify the Rules Docket number and be submitted in triplicate to the address specified above. All communications received on or before the closing date for comments, specified above, will be considered before taking action on the proposed rule. The proposals contained in this notice may be changed in light of the comments received. Comments are specifically invited on the overall regulatory, economic, environmental, and energy aspects of the proposed rule. All comments submitted will be available, both before and after the closing date for comments, in the Rules Docket for examination by interested persons. A report that summarizes each FAA-public contact concerned with the substance of this proposal will be filed in the Rules Docket. Commenters wishing the FAA to acknowledge receipt of their comments submitted in response to this notice must submit a self-addressed, stamped postcard on which the following statement is made: ``Comments to Docket No. 91-CE-12AD.'' The postcard will be date stamped and returned to the commenter. Availability of NPRMs Any person may obtain a copy of this NPRM by submitting a request to the FAA, Central Region, Office of the Assistant Chief Counsel, Attention: Rules Docket No. 91-CE-12-AD, Room 1558, 601 E. 12th Street, Kansas City, Missouri 64106. Discussion The FAA has determined that reliance on critical repetitive inspections on aging commuter-class airplanes carries an unnecessary safety risk when a design change exists that could eliminate or, in certain instances, reduce the number of those critical inspections. In determining what inspections are critical, the FAA considers (1) the safety consequences of the airplane if the known problem is not detected by the inspection; (2) the reliability of the inspection such as the probability of not detecting the known problem; (3) whether the inspection area is difficult to access; and (4) the possibility of damage to an adjacent structure as a result of the problem. These factors have led the FAA to establish an aging commuter-class aircraft policy that requires incorporating a known design change when it could replace a critical repetitive inspection. With this policy in mind, the FAA recently conducted a review of existing ADs that apply to Fairchild SA227 series airplanes. Assisting the FAA in this review were (1) Fairchild Aircraft; (2) the Regional Airlines Association (RAA); and (3) several operators of the affected airplanes. From this review, the FAA has identified AD 83-12-01, Amendment 39-4693, as one that should be superseded with a new AD that would require a modification that could eliminate the need for short-interval and critical repetitive inspections. AD 83-12-01 currently requires repetitively inspecting the lower wing skin panel for cracks on certain Fairchild Models SA227-AC and SA227-AT airplanes, and installing wing skin reinforcement doublers if any wing skin crack is found. Fairchild has issued Service Bulletin (SB) No. 227-57-002, Issued: June 6, 1983, Revised: January 23, 1984, which specifies procedures for accomplishing the following on Models SA227-AC and SA227-AT airplanes: dye penetrant inspections of the wing skin panel, and installation of wing skin reinforcement doublers and wing skin stringer ties. Based on its aging commuter-class aircraft policy and after reviewing all available information, the FAA has determined that AD action should be taken to eliminate the repetitive short-interval inspections required by AD 83-12-01, and to prevent fatigue failure of the lower wing skin panels, which could result in loss of control of the airplane. Since an unsafe condition has been identified that is likely to exist or develop in other Fairchild Models SA227-AC and SA227-AT airplanes of the same type design, the proposed AD would supersede AD 83-12-01 with a new AD that would (1) retain the requirement of repetitively inspecting the lower wing skin panel, and installing wing skin reinforcement doublers if any wing skin crack is found; and (2) require either installing wing skin reinforcement doublers or wing skin stringer ties as terminating action for the repetitive inspections. The proposed actions would be accomplished in accordance with Fairchild SB No. 227-57-002, Issued: June 6, 1983, Revised: January 23, 1984. The FAA estimates that 125 airplanes in the U.S. registry would be affected by the proposed AD, that it would take approximately 9 workhours per airplane to accomplish the proposed action if reinforcement doublers were installed (1 workhour/inspection and 8 workhours/modification) or 25 workhours per airplane to accomplish the proposed action if wing skin stringer ties were installed (1 workhour/ inspection and 24 workhours/modification), and that the average labor rate is approximately $55 an hour. Parts cost approximately $56 per airplane for the wing skin reinforcement doublers and $179 per airplane for the wing skin stringer ties. Based on these figures, the total cost impact of the proposed AD on U.S. operators is estimated to be either $68,875 for those airplane operators incorporating the reinforcement doubler modification or $194,250 for those airplane operators utilizing the wing skin stringer ties modification. This cost figure is based on the assumption that no affected airplane owner/operator has accomplished one of the proposed inspection-terminating modifications. The figure does not include repetitive inspection costs. The FAA has no way of determining how many repetitive inspections each owner/operator may incur. The intent of the FAA's aging commuter airplane program is to ensure safe operation of commuter-class airplanes that are in commercial service without adversely impacting private operators. Of the approximately 125 airplanes in the U.S. registry that would be affected by the proposed AD, approximately 76 are operated in scheduled passenger service. A significant number of the remaining 49 airplanes are operated in other forms of air transportation such as air cargo and air taxi. The proposed AD allows 500 hours time-in-service (TIS) before mandatory accomplishment of the design modification. The average utilization of the fleet for those airplanes in commercial commuter service is approximately 25 to 50 hours TIS per week. Based on these figures, operators of commuter-class airplanes involved in commercial operation would have to accomplish the proposed modification within 2 to 5 calendar months after the proposed AD would become effective. For private owners, who typically operate between 100 to 200 hours TIS per year, this would allow 2 to 5 calendar years before the proposed modification would be mandatory. The regulations proposed herein would not have substantial direct effects on the States, on the relationship between the national government and the States, or on the distribution of power and responsibilities among the various levels of government. Therefore, in accordance with Executive Order 12612, it is determined that this proposal would not have sufficient federalism implications to warrant the preparation of a Federalism Assessment. For the reasons discussed above, I certify that this action (1) is not a ``significant regulatory action'' under Executive Order 12866; (2) is not a ``significant rule'' under DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); and (3) if promulgated, will not have a significant economic impact, positive or negative, on a substantial number of small entities under the criteria of the Regulatory Flexibility Act. A copy of the draft regulatory evaluation prepared for this action has been placed in the Rules Docket. A copy of it may be obtained by contacting the Rules Docket at the location provided under the caption ``ADDRESSES''. List of Subjects in 14 CFR Part 39 Air transportation, Aircraft, Aviation safety, Safety. The Proposed Amendment Accordingly, pursuant to the authority delegated to me by the Administrator, the Federal Aviation Administration proposes to amend 14 CFR part 39 of the Federal Aviation Regulations as follows: PART 39--AIRWORTHINESS DIRECTIVES 1. The authority citation for part 39 continues to read as follows: Authority: 49 U.S.C. App. 1354(a), 1421 and 1423; 49 U.S.C. 106(g); and 14 CFR 11.89. Sec. 39.13 [AMENDED] 2. Section 39.13 is amended by removing AD 83-12-01, Amendment 39- 4693, and adding the following new AD to read as follows: Fairchild Aircraft: Docket No. 91-CE-12-AD. Supersedes AD 83-12-01, Amendment 39-4693. Applicability: The following model and serial number airplanes, certificated in any category: ------------------------------------------------------------------------ Model Serial No. ------------------------------------------------------------------------ SA227-AC........ 415, 416, and 420 through 554. SA227-AT........ 423 through 554. ------------------------------------------------------------------------ Compliance: Required as indicated, unless already accomplished. To prevent fatigue failure of the lower wing skin panels, which could result in loss of control of the airplane, accomplish the following: (a) Within the next 50 hours time-in-service (TIS) after the effective date of this AD, unless already accomplished (compliance with AD 83-12-01), dye penetrant inspect the lower wing skin panel in the area of Fuselage Station (FS) 187.0 in accordance with paragraph IIA of the ACCOMPLISHMENT INSTRUCTIONS section of Fairchild Service Bulletin (SB) 227-57-002, Issued: June 6, 1983, Revised: January 23, 1984. (1) If cracks are found, prior to further flight, install reinforcement doublers, part number 27K31013-001 LH and 27K31013-002 RH, in accordance with paragraph IIB of the ACCOMPLISHMENT INSTRUCTIONS section of Fairchild SB 227-57-002, Issued: June 6, 1983, Revised: January 23, 1984. (2) If no cracks are found, reinspect thereafter at intervals not to exceed 50 hours TIS until the modification specified in paragraph (b) of this AD is accomplished. (b) Within the next 500 hours TIS after the effective date of this AD, unless already accomplished as specified in either paragraph (a)(1) of this AD, accomplish one of the following: (1) Install reinforcement doublers, part number 27K31013-001 LH and 27K31013-002 RH, in accordance with paragraph IIB of the ACCOMPLISHMENT INSTRUCTIONS section of Fairchild SB 227-57-002, Issued: June 6, 1983, Revised: January 23, 1984; or (2) Install stringer ties, P/N 27-13869, in accordance with paragraph IIC of the ACCOMPLISHMENT INSTRUCTIONS section of Fairchild SB 227-57-002, Issued: June 6, 1983, Revised: January 23, 1984. (c) Incorporating the modification specified in paragraphs (a)(1) and (b)(1) or (b)(2) of this AD terminates the repetitive inspection requirement of this AD. (d) Special flight permits may be issued in accordance with 14 CFR 21.197 and 21.199 to operate the airplane to a location where the requirements of this AD can be accomplished. (e) An alternative method of compliance or adjustment of the initial or repetitive compliance times that provides an equivalent level of safety may be approved by the Manager, Airplane Certification Office (ACO), 2601 Meacham Boulevard, Fort Worth, Texas 76137-0150. The request shall be forwarded through an appropriate FAA Maintenance Inspector, who may add comments and then send it to the Manager, Fort Worth ACO. Note: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Fort Worth ACO. (f) All persons affected by this directive may obtain copies of the document referred to herein upon request to Fairchild Aircraft, P.O. Box 790490, San Antonio, Texas 78279-0490; or may examine this document at the FAA, Central Region, Office of the Assistant Chief Counsel, Room 1558, 601 E. 12th Street, Kansas City, Missouri 64106. (g) This amendment supersedes AD 83-12-01, Amendment 39-4693. Issued in Kansas City, Missouri, on March 24, 1994. Bobby W. Sexton, Acting Manager, Small Airplane Directorate, Aircraft Certification Service. [FR Doc. 94-7497 Filed 3-29-94; 8:45 am] BILLING CODE 4903-13-U --- Source: Frix Law Library, https://www.frixlaw.com/law-library/documents/fr%3A94-7497. Public record. Not legal advice.