The Rijksluchtvaartdienst (RLD), which is the airworthiness authority for the Netherlands, recently notified the FAA that an unsafe condition may exist on certain Model F28 Mark 0100 series airplanes. The RLD advises that the hinges of the small cargo door on these airplanes are made of aluminum AL2024-T4, which is a material that is sensitive to stress corrosion cracking. Stress corrosion cracking in the hinge of the small cargo door could result in the failure of the hinge. If the hinge fails, the small cargo door could open and/or separate while the airplane is in flight, which could result in rapid decompression and/or structural damage to the airplane.
Fokker has issued Service Bulletin SBF100-52-048, dated March 5, 1993, which describes procedures for performing a one-time high-frequency eddy current (HFEC) inspection to detect cracks in the fuselage mounted half of the hinge assemblies, having part numbers (P/N) A28410-405 and P/N A28410-407,of the small cargo door. Fokker has also issued Service Bulletin SBF100-52-055, dated July 20, 1994, which describes inspection procedures identical to those specified in Service Bulletin SBF100-52-048; however, the inspections would be conducted repetitively, if no cracks are detected. Additionally, Fokker has issued Service Bulletin SBF100-52-043, dated June 12, 1995, which describes procedures for replacement of any cracked hinge assembly with a new hinge assembly having P/N D28410-409. These new hinges are made of aluminum AL7075-T73, which is much less sensitive to stress corrosion cracking than the material used in the existing hinges. In addition, the radii between the lugs were increased, and the web plate thickness was increased for the door-mounted part, to provide better fatigue resistance. The RLD classified these service bulletins as mandatory and issued Dutch airworthiness directive BLA 93-036/2 (A) in order to assure the continued airworthiness of these airplanes in the Netherlands.
This airplane model is manufactured in the Netherlands and is type certificated for operation in the United States under the provisions of section 21.29 of the Federal Aviation Regulations (14 CFR 21.19) and the applicable bilateral airworthiness agreement. Pursuant to this bilateral airworthiness agreement, the RLD has kept the FAA informed of the situation described above. The FAA has examined the findings of the RLD, reviewed all available information, and determined that AD action is necessary for products of this type design that are certificated for operation in the United States.
Since an unsafe condition has been identified that is likely to exist or develop on other airplanes of the same type design registered in the United States, this AD is being issued to prevent separation or opening of the small cargo door while the airplane is in flight, which could result in rapid decompression and/or structural damage to the airplane. This AD requires HFECinspection(s) to detect cracks of the fuselage-mounted half of certain hinge assemblies of the small cargo door, and replacement of any cracked hinge assembly with a certain new hinge assembly. The actions are required to be accomplished in accordance with the service bulletins described previously.
None of the Model F28 Mark 0100 series airplanes affected by this action are on the U.S. Register. All airplanes included in the applicability of this rule currently are operated by non-U.S. operators under foreign registry; therefore, they are not directly affected by this AD action. However, the FAA considers that this rule is necessary to ensure that the unsafe condition is addressed in the event that any of these subject airplanes are imported and placed on the U.S. Register in the future.
Should an affected airplane be imported and placed on the U.S. Register in the future, it would require approximately 2 work hours to accomplish the required actions, at an average labor charge of $60 per work hour. Based on these figures, the cost impact of this AD would be $120 per airplane.
Since this AD action does not affect any airplane that is currently on the U.S. register, it has no adverse economic impact and imposes no additional burden on any person. Therefore, notice and public procedures hereon are unnecessary and the amendment may be made effective in less than 30 days after publication in the Federal Register.
Comments Invited
Although this action is in the form of a final rule and was not preceded by notice and opportunity for public comment, comments are invited on this rule. Interested persons are invited to comment on this rule by submitting such written data, views, or arguments as they may desire. Communications shall identify the Rules Docket number and be submitted in triplicate to the address specified under the caption "ADDRESSES." All communications received on or before the closing date for comments will be considered, and thisrule may be amended in light of the comments received. Factual information that supports the commenter's ideas and suggestions is extremely helpful in evaluating the effectiveness of the AD action and determining whether additional rulemaking action would be needed.
Comments are specifically invited on the overall regulatory, economic, environmental, and energy aspects of the rule that might suggest a need to modify the 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 AD will be filed in the Rules
Docket.
Commenters wishing the FAA to acknowledge receipt of their comments submitted in response to this rule must submit a self-addressed, stamped postcard on which the following statement is made: "Comments to Docket Number 94-NM-213-AD." The postcard will be date stamped and returned to the commenter.
The regulations adopted herein will 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 final rule does 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) 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 final evaluation has been prepared for this action and it is contained in the Rules Docket. A copy of it may be obtained from the Rules Docket at the location provided under the caption "ADDRESSES."
List of Subjects in 14 CFR Part 39
Air transportation, Aircraft, Aviation safety, Incorporation by reference, Safety.
Adoption of the Amendment
Accordingly, pursuant to the authority delegated to me by the Administrator, the Federal Aviation Administration amends part 39 of the Federal Aviation Regulations (14 CFR part 39) as follows:
PART 39 - AIRWORTHINESS DIRECTIVES
1. The authority citation for part 39 continues to read as follows:
Authority: 49 USC 106(g), 40101, 40113, 44701.
39.13 - [Amended]
2. Section 39.13 is amended by adding the following new airworthiness directive: