On September 12, 1997, the FAA issued emergency AD 97-19-16, which is applicable to Fokker Model F28 Mark 0100 series airplanes equipped with Rolls-Royce (RR) Tay 650-15 engines.
That action was prompted by a report that during preparation for takeoff, a Fokker Model F28 Mark 0100 series airplane equipped with Rolls-Royce Tay 650-15 engines sustained an engine fan blade failure, followed by an engine fire. Investigation revealed that five fan blades failed at the root area, three fan blades failed at mid-height, and the remainder were severely damaged.
Further investigation revealed that all five fan blades failed due to rapid high cycle fatigue cracking with low cycle fatigue cracking origin. Evidence of rapid high cycle fatigue cracking indicates that an operational effect is causing high vibratory stresses. Rolls Royce considers that the high cycle fatigue cracking was caused by vibration during previous thrust reverser applications. This condition, if not corrected, could result in uncontained engine fan blade failure due to high cycle fatigue cracking, which could result in loss of thrust from the affected engine and secondary damage to aircraft and/or fire.
FAA s Conclusions
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 21.29) and the applicable bilateral airworthiness agreement. Pursuant to this bilateral airworthiness agreement, the Rijksluchtvaartdienst (RLD), which is the airworthiness authority for the Netherlands, 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.
Explanation of the Requirements of the Rule
Since the unsafe conditiondescribed is likely to exist or develop on other airplanes of the same type design registered in the United States, the FAA issued emergency AD 97-19-16 to require a revision to the FAA-approved Airplane Flight Manual (AFM). The revision includes procedures to prohibit use of reverse engine thrust power settings between idle and emergency maximum.
This AD also requires that operators submit a report to the airplane manufacturer describing any occurrence where the idle reverse thrust limitations specified in this AD are exceeded.
This is considered to be interim action until final action is identified, at which time the FAA may consider further rulemaking.
Publication and Effectivity of AD
Since it was found that immediate corrective action was required, notice and opportunity for prior public comment thereon were impracticable and contrary to the public interest, and good cause existed to make the AD effective immediately by individual notices issued on September 12, 1997, to all known U.S. owners and operators of Fokker Model F28 Mark 0100 series airplanes equipped with Rolls-Royce Tay 650-15 engines. These conditions still exist, and the AD is hereby published in the Federal Register as an amendment to section 39.13 of the Federal Aviation Regulations (14 CFR 39.13) to make it effective as to all persons.
Comments Invited
Although this action is in the form of a final rule that involves requirements affecting flight safety and, thus, was not preceded by notice and an 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 this rule 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 97-NM-246-AD." The postcard will be date stamped and returned to the commenter.
Regulatory Impact
Theregulations 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.
The FAA has determined that this regulation is an emergency regulation that must be issued immediately to correct an unsafe condition in aircraft, and that it is not a "significant regulatory action" under Executive Order 12866. It has been determined further that this action involves an emergency regulation under DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979). If it is determined that this emergency regulation otherwise would be significant under DOT Regulatory Policies and Procedures, a final regulatory evaluation will beprepared and placed in the Rules Docket. A copy of it, if filed, 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, 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 U.S.C. 106(g), 40113, 44701.
39.13 - [Amended]
2. Section 39.13 is amended by adding the following new airworthiness directive: