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Airworthiness Directives; MD Helicopters Inc. Model 369D, 369E, 500N, and 600N Helicopters

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Information about this document as published in the Federal Register.

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AGENCY:

Federal Aviation Administration, DOT.

ACTION:

Final rule; request for comments.

SUMMARY:

This amendment adopts a new airworthiness directive (AD) applicable to MD Helicopters Inc. (MDHI) Model 369D, 369E, 500N, and 600N helicopters with certain analog/digital turbine outlet temperature (TOT) indicators installed. This action requires repetitive calibration testing of the TOT indicating system and corrective actions if necessary. This amendment is prompted by seven reports of erroneous TOT readings and two reports of incorrect wiring harness terminal lugs on the thermocouple wiring. The actions specified in this AD are intended to prevent an erroneous TOT indication, damage to critical engine components, loss of engine power, and a subsequent forced landing.

DATES:

Effective May 22, 2000.

The incorporation by reference of certain publications listed in the regulations is approved by the Director of the Federal Register as of May 22, 2000.

Comments for inclusion in the Rules Docket must be received on or before July 5, 2000.

ADDRESSES:

Submit comments in triplicate to the Federal Aviation Administration (FAA), Office of the Regional Counsel, Southwest Region, Attention: Rules Docket No. 2000-SW-02, 2601 Meacham Blvd., Room 663, Fort Worth, Texas 76137. You may also send comments electronically to the Rules Docket at the following address: 9-asw-adcomments@faa.gov. Start Printed Page 26123

The service information referenced in this AD may be obtained from MD Helicopters Inc., Attn: Customer Support Division, 4555 E. McDowell Rd., Mail Stop M615-GO48, Mesa, Arizona 85215-9797, telephone 1-800-388-3378 or 480-346-6387, datafax 480-346-6813. This information may be examined at the FAA, Office of the Regional Counsel, Southwest Region, 2601 Meacham Blvd., Room 663, Fort Worth, Texas 76137; or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC.

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FOR FURTHER INFORMATION CONTACT:

Elizabeth Bumann, Aviation Safety Engineer, FAA, Los Angeles Aircraft Certification Office, 3960 Paramount Blvd., Lakewood, California 90712-4137, telephone (562) 627-5265; fax (562) 627-5210.

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SUPPLEMENTARY INFORMATION:

This amendment adopts a new airworthiness directive (AD) applicable to MDHI Model 369D, 369E, 500N, and 600N helicopters with certain analog/digital TOT indicators installed. This action requires repetitive testing of the TOT indicating system to verify correct calibration and to take corrective actions if necessary. This amendment is prompted by seven reports of erroneous TOT readings, up to 100 degrees Celsius low. This amendment is also prompted by two reports of incorrect wiring harness terminal lugs on the thermocouple wiring. Reports indicated that some of the TOT readings did not agree with the engine Electronic Control Unit (ECU) and some readings were found to be 4 degrees Celsius to 17 degrees Celsius low. The actions specified in this AD are intended to prevent erroneous TOT indications, which could prevent the flight crew from detecting that an engine temperature limitation has been exceeded. This condition, if not corrected, could result in damage to critical engine components, loss of engine power, and a subsequent forced landing.

The FAA has reviewed MDHI Service Bulletins SB369D-199, SB369E-093, SB500N-019 (for Model 369D, 369E, and 500N helicopters) and SB600N-026 (for Model 600N helicopters), both dated January 11, 2000. These service bulletins describe procedures for calibration testing of the TOT indicating system and corrective actions if necessary. The corrective actions include inspecting TOT wire harness terminal lugs, connector pins, and sockets to verify correct material and installation; retesting the TOT indicating system; and replacing any unairworthy part with an airworthy part. For Model 600N helicopters, Part III of the service bulletin also describes procedures for verifying the electronic control unit (ECU) TOT calibration.

Since an unsafe condition has been identified that is likely to exist or develop on other MDHI model helicopters of these same type designs, this AD is being issued to prevent an erroneous TOT indication, damage to critical engine components, loss of engine power, and a subsequent forced landing. The actions are required to be accomplished in accordance with the service bulletins described previously, except as discussed in the following paragraphs. The short compliance time involved is required because the previously described critical unsafe condition can adversely affect the engine, causing a loss of engine power and a subsequent forced landing of the helicopter. Therefore, initial testing of the TOT indicating system to verify correct calibration is required within the next 50 hours time-in-service (TIS) or on or before June 15, 2000, whichever occurs earlier, and this AD must be issued immediately.

This AD is an interim action. The manufacturer has advised that it currently is developing a modification that will permanently address the unsafe condition.

The service bulletins specify certain serial numbered helicopters with the affected analog/digital TOT indicator installed. The FAA has determined that any Model 369D, 369E, 500N, and 600N helicopter may have the analog/digital TOT indicator, part number (P/N) 369D24513-1 or P/N 9A3420, installed, since the helicopter manufacturer has not developed a modification to correct the unsafe condition. Even subsequently manufactured Model 369D, 369E, 500N, and 600N helicopters may have these analog/digital TOT indicators installed.

The service bulletins recommend accomplishing the TOT system calibration test within 100 hours TIS. The FAA has determined that a 100-hour TIS compliance time would not address the unsafe condition in a timely manner. In developing an appropriate compliance time for this AD, the FAA considered not only the manufacturer's recommendation, but the degree of urgency associated with addressing the unsafe condition, the average utilization of the affected fleet, and the time necessary to perform the test. In light of all these factors, the FAA finds a compliance time within the next 50 hours TIS or on or before June 15, 2000, whichever occurs first, for initiating the required test is an appropriate interval of time that affected helicopters can operate without compromising safety.

Additionally, the FAA has determined that long-term continued operational safety will be better assured by repetitive testing of the TOT indicating system at intervals not to exceed 300 hours TIS, rather than a one-time test, because of reports that the system calibration may shift with service time. A one-time test may not provide the degree of safety assurance necessary to ensure that the TOT indicator is properly calibrated over time.

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.

The FAA estimates that 566 helicopters will be affected by this proposed AD, that it will take approximately 0.5 work hour to accomplish the test, and that the average labor rate is $60 per work hour. The manufacturer has represented in the service bulletins that parts will be provided at no cost to the operator. Based on these figures, the total cost impact of the AD on U.S. operators is estimated to be $16,980, per test cycle for the entire fleet.

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 Start Printed Page 26124concerned with the substance of this AD will be filed in the Rules Docket.

Commenters wishing the FAA to acknowledge receipt of their mailed comments submitted in response to this rule must submit a self-addressed, stamped postcard on which the following statement is made: “Comments to Docket No. 2000-SW-02-AD.” The postcard will be date stamped and returned to the commenter.

The regulations adopted herein will 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. Therefore, it is determined that this final rule does not have federalism implications under Executive Order 13132.

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 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

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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 (

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PART 39—AIRWORTHINESS DIRECTIVES

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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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[Amended]
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2. Section 39.13 is amended by adding a new airworthiness directive to read as follows:

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AD 2000-08-22 MD Helicopters Inc.: Amendment 39-11708, Docket No. 2000-SW-02-AD.

Applicability: Model 369D, 369E, and 500N helicopters, with analog/digital turbine outlet temperature (TOT) indicator, part number (P/N) 369D24513-1, installed; and Model 600N helicopters, with analog/digital TOT indicator, P/N 9A3420, installed; certificated in any category.

Note 1:

This AD applies to each helicopter identified in the preceding applicability provision, regardless of whether it has been otherwise modified, altered, or repaired in the area subject to the requirements of this AD. For helicopters 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 (f) 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: Required as indicated, unless accomplished previously.

To prevent an erroneous TOT indication, damage to critical engine components, loss of engine power, and a subsequent forced landing, accomplish the following:

(a) For Model 369E, 369D, and 500N helicopters: Within the next 50 hours time-in-service (TIS) or on or before June 15, 2000, whichever occurs first; test the TOT indicating system to verify correct calibration in accordance with the Accomplishment Instructions, Part I, of MD Helicopters, Inc. (MDHI) Service Bulletin SB369D-199, SB369E-093, SB500N-019, dated January 11, 2000 (SB). Thereafter, repeat the test at intervals not to exceed 300 hours TIS.

(b) If during any test required by paragraph (a) of this AD the TOT indicator readings for the tester setting temperatures in Table 1, Part I, of the SB are not within the indicator reading range, before further flight, perform the actions in the Accomplishment Instructions, Part I, paragraph (6)(b) of the SB.

(c) For Model 600N helicopters: Within the next 50 hours TIS or on or before June 15, 2000, whichever occurs first; test the TOT indicating system, including the electronic control unit (ECU) TOT sensing system, to verify correct calibration in accordance with the Accomplishment Instructions, Part I, of MDHI SB600N-026, dated January 11, 2000 (SB 600N). Thereafter, repeat the test at intervals not to exceed 300 hours TIS.

(d) If during any calibration test required by paragraph (c) of this AD the TOT indicator readings for the tester setting temperatures in Table 1, Part I, of SB 600N, are not within the indicator reading range, before further flight, perform the actions in the Accomplishment Instructions, Part I, paragraph (7)(b) of SB 600N.

(e) If during any test required by paragraph (c) of this AD the Full Authority Digital Electronic Control (FADEC) maintenance lap-top terminal does not indicate ECU TOT within (5 degrees Celsius of the tester setting in Table 1, Part I, of SB 600N, before further flight, perform the actions in the Accomplishment Instructions, Part III, of the SB 600N.

(f) 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, Los Angeles Aircraft Certification Office. Operators shall submit their requests through an FAA Principal Maintenance Inspector, who may concur or comment and then send it to the Manager, Los Angeles Aircraft Certification Office.

Note 2:

Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Los Angeles Aircraft Certification Office.

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

(h) The tests shall be done in accordance with MD Helicopters Inc. Service Bulletin SB369D-199, SB369E-093, SB500N-019 for Model 369D, 369E, and 500N helicopters and Service Bulletin SB600N-026 for Model 600N helicopters, both dated January 11, 2000. This incorporation by reference was approved by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies may be obtained from MD Helicopters Inc., Attn: Customer Support Division, 4555 E. McDowell Rd., Mail Stop M615-GO48, Mesa, Arizona 85215-9797, telephone 1-800-388-3378 or 480-346-6387; datafax 480-346-6813. Copies may be inspected at the FAA, Office of the Regional Counsel, Southwest Region, 2601 Meacham Blvd., Room 663, Fort Worth, Texas; or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC.

(i) This amendment becomes effective on May 22, 2000.

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Issued in Fort Worth, Texas, on April 18, 2000.

Mark R. Schilling,

Acting Manager, Rotorcraft Directorate, Aircraft Certification Service.

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[FR Doc. 00-11058 Filed 5-4-00; 8:45 am]

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