Airworthiness directives: Dornier,
[Federal Register: September 1, 1999 (Volume 64, Number 169)]
[Rules and Regulations]
[Page 47651-47653]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr01se99-2]
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 96-NM-113-AD; Amendment 39-11270; AD 99-18-04]
RIN 2120-AA64
Airworthiness Directives; Dornier Model 328-100 Series Airplanes
AGENCY: Federal Aviation Administration, DOT.
ACTION: Final rule.
SUMMARY: This amendment adopts a new airworthiness directive (AD), applicable to certain Dornier Model 328-100 series airplanes, that requires repetitive inspections to detect cracking of the support beam of the main landing gear (MLG) fairing, and a permanent repair, if necessary. This AD also requires installation of reinforcement parts for the longitudinal beam of the MLG fairing, which terminates the requirements of this AD. This amendment is prompted by the issuance of mandatory continuing airworthiness information by a foreign civil airworthiness authority. The actions specified by this AD are intended to prevent cracking of the support beam of the MLG fairing, which could result in reduced structural integrity of the lower part of the MLG fairing, and consequent separation of part of the fairing from the airplane and possible damage to the airplane or injury to persons on the ground.
DATES: Effective October 6, 1999.
The incorporation by reference of certain publications listed in the regulations is approved by the Director of the Federal Register as of October 6, 1999.
ADDRESSES: The service information referenced in this AD may be obtained from Fairchild Dornier, Dornier Luftfahrt GmbH, P.O. Box 1103, D-82230 Wessling, Germany. This information may be examined at the Federal Aviation Administration (FAA), Transport Airplane Directorate, Rules Docket, 1601 Lind Avenue, SW., Renton, Washington: or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC.
FOR FURTHER INFORMATION CONTACT: Norman B. Martenson, Manager, International Branch, ANM-116, FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (425) 227-2110; fax (425) 227-1149.
SUPPLEMENTARY INFORMATION: A proposal to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) to include an airworthiness directive (AD) that is applicable to certain Dornier Model 328-100 series airplanes was published as a supplemental notice of proposed rulemaking (NPRM) in the Federal Register on June 9, 1998 (63 FR 31382). That action proposed to require repetitive inspections to detect cracking of the support beam of the main landing gear (MLG) fairing, and a permanent repair, if necessary. That action also proposed to require installation of reinforcement parts for the longitudinal beam of the MLG fairing, which would terminate the requirements of the AD. In addition, that action proposed to limit the applicability of the original NPRM.
Comments Received
Interested persons have been afforded an opportunity to participate in the making of this amendment. Due consideration has been given to the comments received.
Request To Revise Compliance Time
The manufacturer provides an additional statement to comments submitted in response to the original NPRM regarding continued flight after detection of cracking. The manufacturer notes that inspections, repair, and reinforcement of the support beam of the MLG fairing are intended to prevent
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the possibility of separation of part of the fairing from the aircraft and injury to persons on the ground. Since the support beam and MLG fairing are secondary structure, the manufacturer states that if cracks of less than 50 millimeters are found, allowing temporary repairs along with follow-on repetitive inspections every 300 flight hours, as recommended in Dornier Alert Service Bulletin ASB-328-53-010, dated October 13, 1995, does not impair safe operation.
From this comment, the FAA infers that the manufacturer is again requesting that the FAA reconsider the requirement to accomplish a permanent repair prior to further flight if any crack is found during inspection, as specified in paragraph (a)(2) of the proposed AD. The FAA acknowledges that the structure for which repairs may be necessary is considered to be secondary structure, and that an acceptable temporary repair is available. After further consideration, the FAA partially concurs with the request.
The FAA does not concur with all procedures recommended in the alert service bulletin for continued flight following detection of cracking. Specifically, the FAA does not concur that inspections may be allowed to continue indefinitely until crack length exceeds 50 millimeters. The FAA has determined that although continued flight can be allowed under restricted conditions following accomplishment of a temporary repair, the permanent repair must be accomplished within a period of 6 months. Additionally, the FAA does not concur that repeated stop drilling of the crack should be performed as a continuing temporary repair where further cracking is detected. The FAA has determined that, if any subsequent inspection reveals crack growth beyond the stop drilled area, the permanent repair should be accomplished prior to further flight.
However, since the manufacturer has outlined circumstances of unusual need, the FAA concurs that the airplane can be operated safely with a known crack of less than 50 millimeters for a limited period of time under certain conditions. These conditions include accomplishment of a one-time temporary repair prior to further flight after cracking is detected; reinspection at intervals not to exceed 300 flight hours until the permanent repair is accomplished; accomplishment of the permanent repair within 6 months after cracking is detected; and, immediate accomplishment of the permanent repair if cracking beyond the stop drilling is found in subsequent inspections. Paragraph (a) of the final rule has been revised to specify these requirements following detection of cracks.
Request To Revise Applicability
The manufacturer requests that the applicability statement of the proposed AD be revised to include only airplanes on which the procedures specified in Dornier Service Bulletin SB-328-53-184, Revision 1, dated July 2, 1997 (which is referenced in the proposed AD as the appropriate source of service information for accomplishment of terminating action) have not been accomplished. The manufacturer states that some operators have already incorporated the subject service bulletin, and provides an updated list of airplane serial numbers on which the service bulletin has not yet been accomplished.
The FAA concurs with the manufacturers request to limit the applicability to airplanes on which the terminating action described in Service Bulletin SB-328-53-184 has not been accomplished. However, since operators may be accomplishing such action on an ongoing basis, revising airplane serial numbers in the applicability of this AD would not provide an accurate effectivity in the future. Therefore, the FAA has limited the applicability of the final rule to those airplanes on which Dornier Service Bulletin SB-328-53-184, Revision 1, dated July 2, 1997, has not been accomplished.
Conclusion
After careful review of the available data, including the comments noted above, the FAA has determined that air safety and the public interest require the adoption of the rule with the changes described previously. The FAA has determined that these changes will neither increase the economic burden on any operator nor increase the scope of the AD.
Cost Impact
The FAA estimates that 47 Dornier Model 328-100 series airplanes of U.S. registry will be affected by this AD.
It will take approximately I work hour per airplane to accomplish the required inspection, at an average labor rate of $60 per work hour. Based on these figures, the cost impact of the inspection required by this AD on U.S. operators is estimated to be $2,820, or $60 per airplane, per inspection cycle.
It will take approximately 8 work hours per airplane to accomplish the required installation of reinforcement parts, at an average labor rate of $60 per work hour. Required parts will be supplied by the manufacturer at no cost to the operators. Based on these figures, the cost impact of the installation required by this AD on U.S. operators is estimated to be $22,560, or $480 per airplane.
The cost impact figures discussed above are based on assumptions that no operator has yet accomplished any of the requirements of this AD action, and that no operator would accomplish those actions in the future if this AD were not adopted.
Should an operator be required to accomplish the permanent repair of cracked structure, it would take approximately 3 work hours per airplane to accomplish it, at an average labor rate of $60 per work hour. Required parts would be supplied by the manufacturer at no cost to the operators. Based on these figures, the cost impact of the repair action, if accomplished, is estimated to be $180 per airplane.
Regulatory Impact
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.
For the reasons discussed above, I certify that this action (1) is not a ``significant regulatory action'' under Executive Order 12866; (2) is not a ``significant rule'' under DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); and (3) will not have a significant economic impact, positive or negative, on a substantial number of small entities under the criteria of the Regulatory Flexibility Act. A final evaluation has been prepared for this action and it is contained in the Rules Docket. A copy of it 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:
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PART 39--AIRWORTHINESS DIRECTIVES
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The authority citation for part 39 continues to read as follows:
Authority: 49 U.S.C. 106(g), 40113, 44701.
Sec. 39.13 [Amended]
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Section 39.13 is amended by adding the following new airworthiness directive:
99-18-04 Dornier Luftfahrt GMBH: Amendment 39-11270. Docket 96-NM- 113-AD.
Applicability: Model 328-100 series airplanes, serial numbers 3005, 3008, 3009, and 3011 through 3079 inclusive; except airplanes on which Dornier Service Bulletin SB-328-53-184, Revision 1, dated July 2, 1997, has been accomplished; certificated in any category.
Note 1: This AD applies to each airplane 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 airplanes 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 reduced structural integrity of the lower part of the main landing gear (MLG) fairing, and consequent separation of part of the fairing from the airplane and possible damgae to the airplane or injury to persons on the ground, accomplish the following:
Inspections and Repairs
(a) Within 300 hours time-in-service after the effective date of this AD, perform a visual inspection to detect cracking of the lower attachment flanges in the area of the bend radii of the forward and aft support beams of the MLG, in accordance with Dornier Alert Service Bulletin ASB-328-53-010, dated October 13, 1995.
(1) If no cracking is found, repeat the inspection thereafter at intervals not to exceed 300 hours time-in-service, until the actions required by either paragraph (a)(2)(iii) or (b) of this AD have been accomplished.
(2) If any cracking is found and the crack is less than 50 millimeters (1.97 inches) in length, accomplish paragraphs (a)(2)(i), (a)(2)(ii), and (a)(2)(iii) of this AD.
(i) Prior to further flight, accomplish stop drilling as a one- time temporary repair in accordance with the alert service bulletin.
(ii) Repeat the inspection thereafter at intervals not to exceed 300 hours time-in-service until accomplishment of paragraph (a)(2)(iii) of this AD. If any inspection reveals that the cracking has grown beyond the stop drilled area, prior to further flight, accomplish paragraph (a)(2)(iii) of this AD.
(iii) Within 6 months after the cracking is detected, accomplish the permanent repair in accordance with the alert service bulletin. Accomplishment of the permanent repair constitutes terminating action for the repetitive inspections required by this AD.
(3) If any crack is found and the crack is greater than or equal to 50 millimeters (1.97 inches) in length, prior to further flight, accomplish the permanent repair in accordance with the alert service bulletin. Accomplishment of the permanent repair constitutes terminating action for the repetitive inspections by this AD.
Terminating Modification
(b) Within 3,000 hours time-in-service after the effective date of this AD, install reinforcement parts for the longitudinal beam of the MLG, in accordance wtih Dornier Service Bulletin SB-328-53-184, Revision 1, dated July 2, 1997. Accomplishment of this installation constitutes terminating action for the requirements of this AD.
Alternative Methods of Compliance
(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, International Branch, ANM-116, FAA, Transport Airplane Directorate. Operators shall submit their requests through an appropriate FAA Principal Maintenance Inspector, who may add comments and then send it to the Manager, International Branch, ANM-116.
Note: 2: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the International Branch, ANM-116.
Special Flight Permits
(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 airplane to a location where the requirements of this AD can be accomplished.
Incorporation by Reference
(e) The actions shall be done in accordance with Dornier Alert Service Bulletin ASB-328-53-010, dated October 13, 1995; and Dornier Service Bulletin SB-328-53-184, Revision 1, dated July 2, 1997. 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 Fairchild Dornier, Dornier Luftfahrt GmbH, P.O. Box 1103, D-82230 Wessling, Germany. Copies may be inspected at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the Office of the Federal Register, 800 North Capitol Street, NW., Suite 700, Washington, DC.
Note 3: The subject of this AD is addressed in German airworthiness directives 95-413, dated November 2, 1995, and 97-073, dated March 27, 1997.
(f) This amendment becomes effective on October 6, 1999.
Issued in Renton, Washington, on August 23, 1999. Vi L. Lipski, Acting Manager, Transport Airplane Directorate, Aircraft Certification Service.
[FR Doc. 99-22390Filed8-31-99; 8:45 am]
BILLING CODE 4910-13-M
