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Airworthiness Directives; Honeywell International Inc. (formerly AlliedSignal Inc. and Garrett Turbine Engine Company) TPE331-8, -10N, and -12B Turboprop Engines

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Federal Aviation Administration, DOT.


Final rule; request for comments.


This amendment adopts a new airworthiness directive (AD) that is applicable to Honeywell International Inc. (formerly AlliedSignal Inc. and Garrett Turbine Engine Company) TPE331-8, -10N, and -12B turboprop engines with certain electronic engine controls (EEC's) installed. This AD requires revising the Emergency and Normal Procedures section of the applicable Airplane Flight Manual (AFM) until the existing EEC's are replaced. This amendment is prompted by a report of an engine experiencing an uncommanded full power increase during an approach while both engine power levers were at the flight idle gate. The actions specified in this AD are intended to minimize exposure to flight and ground operations that could lead to the loss of control of the airplane due to asymmetric thrust and an uncommanded torque increase.


Effective November 19, 2001.

Comments for inclusion in the Rules Docket must be received on or before December 18, 2001.


Submit comments in triplicate to the Federal Aviation Administration (FAA), New England Region, Office of the Regional Counsel, Attention: Rules Docket No. 2000-NE-39-AD, 12 New England Executive Park, Burlington, MA 01803-5299. Comments may also be sent via the Internet using the following address: Comments sent via the Internet must contain the docket number in the subject line.

The temporary revisions referenced in this AD may be obtained from Cessna Propeller Aircraft Customer Service, P.O. Box 7706, Wichita, Kansas, 67277; telephone: (316) 517-5800, fax: (316) 517-7271.

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Joseph Costa, Aerospace Engineer, Los Angeles Aircraft Certification Office, FAA, Transport Airplane Directorate, 3960 Paramount Blvd., Lakewood, CA 90712-4137; telephone (562) 627-5246; fax (562) 627-5210. Contact Bob Adamson, Aerospace Engineer, Wichita Aircraft Certification Office, 1801 Airport Road, Room 100, Wichita KS 67209; telephone (316) 946-4145; fax (316) 946-4407 with any questions and comments regarding AFM procedures pertaining to this AD.

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In September 1999, a TPE331-10N turboprop engine experienced an uncommanded increase to full power during an approach while both engine power levers were at the flight idle gate. The pilot aborted the approach and re-established power symmetry by applying full power to the opposite engine. After reverting to manual mode, the pilot made a safe landing. Based on engine-propeller stand testing of certain engine control configurations, and a review of prior field reports of uncommanded torque or fuel increases, the FAA has determined that uncommanded torque may peak to 150% within 5 seconds of an initial torque acceleration. In addition, the number of uncommanded engine accelerations in service have been gradually increasing. Nine events of uncommanded power increases have occurred, in varying degrees of severity, within the past 17 years. This condition, if not corrected, could result in loss of control of the airplane due to asymmetric thrust from an uncommanded power increase.

Actions Required by This AD

Since an unsafe condition has been identified that is likely to exist or develop on other engines of this same type design, this AD requires a temporary revision to the Emergency and Normal Procedures section of the applicable FAA Approved AFM for each applicable engine installation in a multi-engine airplane. The temporary AFM revision provides procedures for minimizing asymmetric thrust resulting from uncommanded power increases in flight and on ground. The temporary AFM revision is effective for an individual multi-engine airplane until the existing EEC for each engine is replaced with a redesigned and reworked EEC. These AFM changes have been coordinated with the FAA Certification Office responsible for the certification of the airplanes involved.

The rework and testing of the EEC can only be accomplished at Honeywell's Repair Station in Tucson, Arizona, whose repair capacity and rate-of-repair is limited. The FAA has determined that the July 23, 2003 date was the earliest date to complete the rework and testing of all 775 existing EEC's. This determination assumes that the operator act expeditiously and coordinate this EEC repair with the Honeywell Repair Station.

Finding That Immediate Adoption Is Necessary

Since a situation exists that requires the immediate adoption of this regulation, it is found that notice and opportunity 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 Start Printed Page 53084invited 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 2000-NE-39-AD.” The postcard will be date stamped and returned to the commenter.

Regulatory Impact

This amendment 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 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.

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List of Subjects in 14 CFR Part 39

  • Air transportation
  • Aircraft
  • Aviation safety
  • Safety
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Adoption of the Amendment

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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:

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1. The authority citation for part 39 continues to read as follows:

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Authority: 49 U.S.C. 106(g), 40113, 44701.

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

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2001-21-02  Honeywell International Inc.: Amendment 39-12472. Docket 2000-NE-39-AD.


This airworthiness directive (AD) is applicable to Honeywell International Inc. (formerly AlliedSignal Inc. and Garrett Turbine Engine Company) TPE331-8, -10N, and -12B turboprop engines with electronic engine controls (EEC's) part numbers (P/N's) 2101322-1, -4, -11, -12, -13, -14, -15 or -16 installed. These engines are installed on but not limited to Cessna Aircraft Company Model 441 Conquest airplanes.

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 or operator must request approval for an alternative method of compliance in accordance with paragraph (g) 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 with this AD is required as indicated, unless already done.

To minimize exposure to flight and ground operations that could lead to the loss of control of the airplane due to asymmetric thrust and an uncommanded torque increase, do the following:

Amending of the Airplane Flight Manual

(a) Within 30 days after the effective date of this AD, amend the applicable FAA Approved Cessna Airplane Flight Manual (AFM) Emergency Procedures and Normal Procedures Section to provide interim emergency procedures to flight crews, by inserting the Temporary Revisions specified in the following table:

Temporary Revisions by Airplane Model and Serial Number (SN) and AFM Affected

Airplane model and serial No. (SN)AFM affectedTemporary revision
(1) Cessna Model 441; SN's 441-0001 through 441-0172D1561-14-13PH through Revision 14, dated January 9, 1998D1561-14TR2 through D1561-14, dated 14TR8 dated November 20, 2000
D1561-14TR9 dated April 11, 2001.
(2) Cessna Model 441; SN's 441-0173 and higherD1586-11-13PH through Revision 11, dated January 9, 1998D1586-11TR2 through D1586-11TR5 dated November 20, 2000.
D1586-11TR7 and D1586-11TR8 dated November 20, 2000.
D1586-11TR9 dated March 7, 2001.
D1586-11TR10 dated April 11, 2001.

(b) Owners or operators of airplanes that have been modified by supplemental type certificate, where the AFM conflicts with the TR's specified in (a)(1) and (a)(2) of this AD, must contact Los Angeles Aircraft Certification Office (LAACO) to have their AFM's reviewed and approved.

Replacement of Electronic Engine Controls

(c) Replace all existing EEC's P/N's 2101322-1, -4, -11, -12, -13, -14, -15 and -16 with serviceable EECs before August 31, 2003.

(d) Information regarding the replacement of existing EEC's is available in Honeywell Alert Service Bulletins TPE331-A76-0035 dated July 23, 2001, TPE331-A76-0036 dated Start Printed Page 53085July 23, 2001, and TPE331-A76-0037 dated July 23, 2001.

Removal of Temporary Revisions

(e) When all EEC's have been replaced in the airplane with serviceable EEC's, remove the applicable Temporary Revisions, specified in the preceding table, from the airplane flight manual.


(f) For the purposes of the AD, a serviceable EEC is an EEC with a P/N that is not specified in this AD.

Alternative Methods of Compliance

(g) 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, LAACO. Operators must submit their requests through an appropriate FAA Principal Maintenance Inspector, who may add comments and then send it to the Manager, LAACO.

Note 2:

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

Effective Date of This AD

(h) This amendment becomes effective on November 19, 2001.

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Issued in Burlington, Massachusetts, on October 12, 2001.

Thomas A. Boudreau,

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

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[FR Doc. 01-26323 Filed 10-18-01; 8:45 am]