On October 3, 2001, the Federal Aviation Administration (FAA) issued Emergency Airworthiness Directive (AD) 2001-20-51, applicable to Rolls-Royce Corporation (formerly Allison Engine Company) models 250-C20, -C20B, -C20F, -C20R, -C20R/1, -C20R/2, -C20S, and -C20W turboshaft engines, and 250-B17, -B17C, -B17D, -B17E, -B17F, -B17F/1, and -B17F/2 turboprop engines, which requires replacement of any helical torquemeter gearshaft assembly with 100 hours or less time-since-new (TSN) with a serviceable helical torquemeter gearshaft assembly, before further flight. That action was prompted by a report of uncontained release of power turbine blades and disk fragments caused by engine overspeed, resulting in an uncommanded engine shutdown, engine fire, and damage to the aircraft. This condition, if not corrected, could result in uncontained release of power turbine blades and disk fragments caused by engine overspeed, resulting in an uncommanded engine shutdown, enginefire, and damage to the aircraft. Since that Emergency AD was issued, it has been found that engine model 250-C20J was inadvertantly omitted from emergency AD 2001-20-51, and is added to the applicability section of this AD.
FAA's Determination of an Unsafe Condition and Required Actions
Since the unsafe condition described is likely to exist or develop on other engines of the same type design, the FAA issued emergency AD 2001-20-51 to prevent uncontained release of power turbine blades and disk fragments caused by engine overspeed, resulting in an uncommanded engine shutdown, engine fire, and damage to the aircraft. This AD requires replacement of any helical torquemeter gearshaft assembly with 100 hours or less time-since-new (TSN) with a serviceable helical torquemeter gearshaft assembly, before further flight.
Immediate Adoption of This AD
Since a situation exists that requires the immediate adoption of this regulation, it is found that notice and opportunity forprior public comment hereon are impracticable, and that good cause exists for making this amendment effective in less than 30 days.
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 should 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 beneeded.
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 notice must submit a self-addressed, stamped postcard on which the following statement is made: "Comments to Docket Number 2001-NE-38." The postcard will be date stamped and returned to the commenter.
Regulatory Analysis
This final rule does not have federalism implications, as defined in Executive Order 13132, because it would not have a substantial direct effect on the States, on the relationship between the national governmentand the States, or on the distribution of power and responsibilities among the various levels of government. Accordingly, the FAA has not consulted with state authorities prior to publication of this final rule.
The FAA has determined that this regulation is an emergency regulation that must be issued immediately to
correct an unsafe condition in aircraft, and 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 be prepared 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.
Sec. 39.13 [Amended]
2. Section 39.13 is amended by adding the following new airworthiness directive: