01-29950. Airworthiness Directives; Rolls-Royce Corporation (Formerly Allison Engine Company) 250-C20 Series Turboshaft and 250-B17 Series Turboprop Engines

AGENCY:

Federal Aviation Administration, DOT.

ACTION:

Final rule, request for comments.

SUMMARY:

This amendment supersedes an emergency airworthiness directive (AD) that was sent previously to all known U.S. owners and operators of 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 by individual letters. That action required 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 amendment 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 amendment requires the same replacement, and adds engine model -250-C20J to the applicability section of this AD. The actions specified by this AD are intended 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.

DATES:

Effective December 19, 2001.

Comments for inclusion in the Rules Docket must be received on or before February 4, 2002.

ADDRESSES:

Submit comments in triplicate to the Federal Aviation Administration (FAA), New England Region, Office of the Regional Counsel, Attention: Rules Docket No. 2001-NE-38-AD, 12 New England Executive Park, Burlington, MA 01803-5299. Comments may be inspected at this location, by appointment, between 8 a.m. and 4:30 p.m., Monday through Friday, except Federal holidays. Comments may also be sent via the Internet using the following address: “[e-mail]”. Comments sent via the Internet must contain the docket number in the subject line.

FOR FURTHER INFORMATION CONTACT:

John Tallarovic, Aerospace Engineer, Chicago Aircraft Certification Office, FAA, Small Airplane Directorate, 2300 East Devon Avenue, Des Plaines, IL 60018; telephone [phone], fax [phone].

SUPPLEMENTARY INFORMATION:

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, engine fire, 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 opportunuty for prior 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 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 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 government and 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.

§ 39.13

[Amended]

2. Section 39.13 is amended by adding the following new airworthiness directive:

2001-24-12 Rolls-Royce Corporation (formerly Allison Engine Company): Amendment 39-12529. Docket No. 2001-NE-38-AD.

Applicability

This airworthiness directive (AD) is applicable to Rolls-Royce Corporation (formerly Allison Engine Company) models 250-C20, -C20B, -C20F, -C20J, -C20R, -C20R/1, -C20R/2, -C20S, and -C20W turboshaft engines, and 250-B17, -B17C, -B17D, -B17E, -B17F, -B17F/1, and -B17F/2 turboprop engines. These engines are used on, but not limited to Aerospatiale AS355; Agusta A109; A109A, A109C; Bell 206B, 206L, 206LT; Enstrom TH28; McDonnell Douglas 500C, 500D, 500E, 520N; Rogerson-Hiller FH1100; Schweizer TH330; Soloy Conversions Bell 47/47G, Hiller UH-12; American Jet Industries/Cessna 402, 414; and ASTA/GAF Nomad N-22 aircraft.

Note 1:

This AD applies to each engine identified in the preceding applicability provision, regardless of whether it has been modified, altered, or repaired in the area subject to the requirements of this AD. For engines that have been modified, altered, or repaired so that the performance of the requirements of this AD is affected, the owner/operator must request approval for an alternative method of compliance in accordance with paragraph (d) of this AD. The request should include an assessment of the effect of the modification, alteration, or repair on the unsafe condition addressed by this AD; and, if the unsafe condition has not been eliminated, the request should include specific proposed actions to address it.

Compliance

Compliance with this AD is required as indicated, unless already done.

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, do the following:

(a) Before further flight, remove helical torquemeter gearshaft assemblies part numbers (P/N's) 23035299 and 23038191 that have accumulated 100 hours or less time-since-new (TSN). Replace with a serviceable helical torquemeter gearshaft assembly.

(b) After the receipt of this AD, do not install any helical torquemeter gearshaft assembly P/N 23035299 or 23038191 that has accumulated 100 hours or less TSN.

Definition

(c) For the purposes of this AD, the following helical torquemeter gearshaft assemblies are considered serviceable parts:

(1) P/N's 23035299 and 23038191 that have greater than 100 hours TSN.

(2) An assembly with a P/N other than P/N's 23035299 and 23038191.

Alternative Methods of Compliance

(d) An alternative method of compliance or adjustment of the compliance time that provides an acceptable level of safety may be used if approved by the Manager, Chicago Aircraft Certification Office. Operators must submit their requests through an appropriate FAA Principal Maintenance Inspector, who may add comments and then send it to the Manager, Chicago Aircraft Certification Office.

Note 2:

Information concerning the existence of approved alternative methods of compliance with this airworthiness directive, if any, may be obtained from the Chicago Aircraft Certification Office.

Special Flight Permits

(e) Special flight permits may be issued in accordance with 21.197 and 21.199 of the Federal Aviation Regulations (14 CFR 21.197 and 21.199) to operate the aircraft to a location where the requirements of this AD can be done.

Effective Date of This AD

(f) This amendment becomes effective December 19, 2001.

Issued in Burlington, Massachusetts, on November 27, 2001.

Francis A. Favara,

Acting Manager, Engine and Propeller Directorate, Aircraft Certification Service.