AD 99-22-01

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AD Number:
99-22-01
Document Type:
AD Final Rules
Docket Number:
99-SW-59-AD
Subject Heading:
Airworthiness Directives; Eurocopter Deutschland GmbH Model EC135 P1 and T1 Helicopters
Subject:
Tail Boom Frame Flange Inspection
Status:
Current
Citation:
Federal Register: December 02, 1999 (Volume 64, Number ??)
Citation Publish Date:
12/02/1999
Effective Date:
12/17/1999
Make:
Airbus Helicopters Deutschland GmbH
Model:
EC135P1 | EC135T1
Product Type:
Aircraft
Product Subtype:
Rotorcraft
Affected AD:
Superseded AD:
Affected By:
Superseded By:
Service/Office:
AIR-700: Compliance & Airworthiness Division
Office of Primary Responsibility:
AIR-760: Central Certification Branch
CFR Part Reference:
Part 39 [64 FR 67471 12/02/99]
Comments:
AIRWORTHINESS DIRECTIVES FINAL RULES: 99-22-01
CITATION:   [Federal Register: December 02, 1999 (Volume 64, Number ??)]

PAGE NUMBER:   [Page 67471]

DOCKET NUMBER:   99-SW-59-AD

AMENDMENT:   39-11439

AD NUMBER:   99-22-01

SUBJECT HEADING:   Airworthiness Directives; Eurocopter Deutschland GmbH Model EC135 P1 and T1 Helicopters

ACTION:   Final rule; request for comments

SUMMARY:   This document publishes in the Federal Register an amendment adopting Airworthiness Directive (AD) 99-22-01, which was sent previously to all known U.S. owners and operators of Eurocopter Deutschland GmbH (ECD) Model EC135 P1 and T1 helicopters by individual letters. This AD requires, before further flight and at specified time intervals until a modified tail boom connecting frame flange (frame flange) is installed, inspecting and replacing, if necessary, the frame flange. This AD also requires, within 7 days, installing an additional bearing support on the frame flange. Thereafter, this AD requires visually inspecting the frame flange for cracks or misalignment of the slippage marks at specified time intervals. This amendment is prompted by the discovery of a crack in the frame flange at the attachment points of the tail rotor drive shaft bearing support. The actions specified by this AD are intended to prevent a fracture of the bearing frame flange, failure of the tail rotor drive shaft, and subsequent loss of control of the helicopter.

DATES:   Effective December 17, 1999. To all persons except those persons to whom it was made immediately effective by Emergency Priority Letter AD 99-22-01, issued on October 12, 1999, which contained the requirements of this amendment. The incorporation by reference of certain publications listed in the regulations is approved by the Director of the Federal Register as of December 17, 1999. Comments for inclusion in the Rules Docket must be received on or before January 31, 2000.

ADDRESSES:   Submit comments in triplicate to the Federal Aviation Administration (FAA), Office of the Regional
Counsel, Southwest Region, Attention: Rules Docket No. 99-SW-59-AD, 2601 Meacham Blvd., Room 663, Fort Worth,
Texas 76137.
The applicable service information may be obtained from American Eurocopter Corporation, 2701 Forum Drive,
Grand Prairie, Texas 75053-4005, telephone (972) 641-3460, fax (972) 641-3527. This information may be examined 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.

FOR FURTHER INFORMATION CONTACT:   Paul J. Madej, Aerospace Engineer, FAA, Rotorcraft Directorate,
Rotorcraft Standards Staff, 2601 Meacham Blvd., Fort Worth, Texas 76137, telephone (817) 222-5125, fax
(817) 222-5961.

SUPPLEMENTARY INFORMATION:  
On October 12, 1999, the FAA issued Emergency Priority Letter AD 99-22-01, applicable to ECD Model EC135 P1 and T1 helicopters, which requires, before further flight and at specified time intervals until an additional bearing support bracket is installed on the frame flange, inspecting and replacing, if necessary, the frame flange. The AD also requires, within 7 days, adding the additional bearing support bracket to the frame flange. Thereafter, the AD requires visually inspecting the frame flange for cracks or misalignment of the slippage marks at specified time intervals. That action was prompted by the discovery of a crack in the frame flange at the attachment points of the tail rotor drive shaft bearing support. The crack, discovered during an inspection of an ECD Model EC135 helicopter, was caused by metal fatigue due to unanticipated loads at this location. This condition, if not corrected, could result in a fracture of the bearing frame flange, failure of the tail rotor drive shaft, and subsequent loss of control of the helicopter.

The Luftfahrt-Bundesamt (LBA), which is the airworthiness authority for the Federal Republic of Germany, notified the FAA that an unsafe condition may exist on ECD Model EC135 P1 and T1 helicopters, serial numbers (S/N) 0005 through 0120. The LBA issued AD 1999-199/3, dated October 5, 1999, applicable to ECD Model EC135 helicopters, S/N 0005 through 0120. The LBA advises that during an inspection a crack was detected on the frame flange of the tail rotor drive shaft bearing support.

The FAA has reviewed ECD Alert Service Bulletins EC 135-53A-009, dated March 23, 1999, and EC 135-53A-010, Revision 2, dated July 22, 1999 (ASB). The ASB's describe procedures for conducting a dye-penetrant crack inspection before further flight and conducting repetitive inspections at intervals not to exceed 15 hours time-in-service (TIS) until the helicopters are fitted with an additional bearing support bracket at bearing location I as identified in the ASB's. ASB EC 135-53A-010, Revision 2, also defines the 50-hour repetitive inspection necessary after the modification is accomplished.

This helicopter model is manufactured in the Federal Republic of Germany and is type certificated for operation in the United States under the provision 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 LBA has kept the FAA informed of the situation described above. The FAA has examined the findings of the LBA, reviewed all available information, and determined that AD action is necessary for products of this type design that are certificated for operations in the United States.

Since the unsafe condition described is likely to exist or develop on other ECD Model EC135 P1 and T1 helicopters of the same type design, the FAA issued Emergency Priority Letter AD 99-22-01 to prevent a fracture of the bearing frame flange, failure of the tail rotor drive shaft, and subsequent loss of control of the helicopter. The AD requires, before further flight, conducting a dye-penetrant inspection of the tail boom frame flange at the attachment points of the tail rotor drive shaft bearing as shown in location I in Figure 1 of the ASB's. If a crack is found, the AD requires replacing the tail boom frame flange before further flight. The dye-penetrant inspection of the frame flange is required at intervals not to exceed 15 hours TIS until an additional bearing support bracket has been installed. The AD also requires, within 7 days, modifying the frame flange by installing an additional bearing support bracket. After modifying the frame flange, a visual inspection for a crack or for misalignment of the slippage marks is to be conducted at intervals not to exceed 50 hours TIS. The actions must be accomplished in accordance with the ASB's described previously. The short compliance time involved is required because the previously described critical unsafe condition can adversely affect the structural integrity of the helicopter. Therefore, inspecting and replacing, if necessary, the frame flange is required before further flight; modifying the frame flange is required within 7 days; and inspecting the modified frame flange is required at 50 hour TIS intervals; and this AD must be issued immediately.

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 letters issued on October 12, 1999 to all known U.S. owners and operators of ECD Model EC135 P1 and T1 helicopters. 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 to all persons.

The FAA estimates that 14 helicopters of U.S. registry will be affected by this AD, that it will take approximately 2 work hours per helicopter to accomplish the dye-penetrant inspections, 48 work hours per helicopter to replace the frame flange, if necessary, and 3 work hours per helicopter to install the additional bearing support bracket on the frame flange. The average labor rate is $60 per work hour. The manufacturer has stated that required parts will be provided at no cost. Based on these figures, the total cost impact of the AD on U.S. operators is estimated to be $24,360, assuming conducting one dye-penetrant inspection on each helicopter, replacing the frame flange in half the fleet, and modifying the frame flange in all the 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 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 No. 99-SW-59-AD." The postcard will be date stamped and returned to the commenter.

The regulations 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 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, Incorporation by reference, 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 a new airworthiness directive to read as follows:

REGULATORY TEXT:  
99-22-01 EUROCOPTER DEUTSCHLAND GmbH: Amendment 39-11439. Docket No. 99-SW-59-AD.
Applicability: Model EC135 P1 and T1 helicopters, serial numbers 0005 through 0120, inclusive, 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 (c) 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 a fracture of the bearing connecting frame flange (frame flange), failure of the tail rotor drive shaft, and subsequent loss of control of the helicopter, accomplish the following:

(a) Before further flight, conduct a dye-penetrant inspection of the tail boom frame flange at the attachment points of the tail rotor drive shaft bearing (see location I in Figure 1 in Eurocopter Deutschland GmbH (ECD) Alert Service Bulletin (ASB) EC 135-53A-010, Revision 2, dated July 22, 1999) in accordance with the Accomplishment Instructions, paragraph 3.A., of ASB EC 135-53A-010, Revision 2, dated July 22, 1999, and Figure 1 of ASB 135-53A-009, dated March 23, 1999. If a crack is found, replace the unairworthy frame flange with an airworthy frame flange. Thereafter, conduct the dye-penetrant inspection at intervals not to exceed 15 hours time-in-service (TIS) until the requirements in paragraph (b) of this AD are accomplished.

(b) Within 7 days, install an additional bearing support bracket on the frame flange in accordance with the Accomplishment Instructions, paragraph 3.B., of ASB EC 135-53A-010, Revision 2 dated July 22, 1999. Thereafter, at intervals not to exceed 50 hours TIS, inspect for a crack or for misalignment of the slippage marks on the frame flange.

(c) 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, Regulations Group, Rotorcraft Directorate, FAA. Operators shall submit their requests through an FAA Principal Maintenance Inspector, who may concur or comment and then send it to the Manager, Regulations Group.

NOTE 2: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Regulations Group, Rotorcraft Directorate.

(d) 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.

(e) The dye-penetrant inspections shall be done in accordance with the Accomplishment Instructions, paragraph 3.A., of Eurocopter Deutschland GmbH Alert Service Bulletin EC 135-53A-010, Revision 2, dated July 22, 1999, and Figure 1 of Eurocopter Deutschland GmbH Alert Service Bulletin 135-53A-009, dated March 23, 1999. The modification shall be done in accordance with the Accomplishment Instructions, paragraph 3.B., of Eurocopter Deutschland GmbH Alert Service Bulletin EC 135-53A-010, Revision 2, dated July 22, 1999. 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 American Eurocopter Corporation, 2701 Forum Drive, Grand Prairie, Texas 75053-4005, telephone (972) 641-3460, fax (972) 641-3527. 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.

(f) This amendment becomes effective on December 17, 1999, to all persons except those persons to whom it was made immediately effective by Emergency Priority Letter AD 99-22-01, issued October 12, 1999, which contained the requirements of this amendment.

FOOTER:   Issued on November 17, 1999 becomes effective upon receipt.