Airworthiness directives: Dornier,
[Federal Register: July 22, 1998 (Volume 63, Number 140)]
[Proposed Rules]
[Page 39252-39254]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr22jy98-24]
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 98-NM-140-AD]
RIN 2120-AA64
Airworthiness Directives; Dornier Model 328-100 Series Airplanes
AGENCY: Federal Aviation Administration, DOT.
ACTION: Notice of proposed rulemaking (NPRM).
SUMMARY: This document proposes the adoption of a new airworthiness directive (AD) that is applicable to certain Dornier Model 328-100 series airplanes. This proposal would require repetitive tests to detect internal leakage of hydraulic fluid within the hydraulic components of the ground spoiler system and to detect a buildup of pressure in the return line of the bypass valve, and corrective action, if necessary; installation of additional hydraulic lines and an additional hydraulic shutoff valve in the ground spoiler system; and replacement of the valve block of the ground spoiler system with a new part. This proposal also would require eventual replacement of the relief restrictor valves of the ground spoiler system with redesigned parts, which would constitute terminating action for the repetitive tests. This proposal is prompted by issuance of mandatory continuing airworthiness information by a foreign civil airworthiness authority. The actions specified by the proposed AD are intended to prevent the ground spoilers from unlocking and deploying during takeoff or in flight, and consequent reduced controllability of the airplane.
DATES: Comments must be received by August 21, 1998.
ADDRESSES: Submit comments in triplicate to the Federal Aviation Administration (FAA), Transport Airplane Directorate, ANM-114, Attention: Rules Docket No. 98-NM-140-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056. Comments may be inspected at this location between 9:00 a.m. and 3:00 p.m., Monday through Friday, except Federal holidays.
The service information referenced in the proposed rule may be obtained from FAIRCHILD DORNIER, DORNIER Luftfahrt GmbH, P.O. Box 1103, D-82230 Wessling, Germany. This information may be examined at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington.
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:
Comments Invited
Interested persons are invited to participate in the making of the proposed rule by submitting such written data, views, or arguments as they may desire. Communications shall identify the Rules Docket number and be submitted in triplicate to the address specified above. All communications received on or before the closing date for comments, specified above, will be considered before taking action on the proposed rule. The proposals contained in this notice may be changed in light of the comments received.
Comments are specifically invited on the overall regulatory, economic, environmental, and energy aspects of the proposed 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 summarizing each FAA-public contact concerned with the substance of this proposal will be filedin 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 98-NM-140-AD.'' The postcard will be date stamped and returned to the commenter.
Availability of NPRMs
Any person may obtain a copy of this NPRM by submitting a request to the FAA, Transport Airplane Directorate, ANM-114, Attention: Rules Docket No. 98-NM-140-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056.
Discussion
The Luftfahrt-Bundesamt (LBA), which is the airworthiness authority for Germany, notified the FAA that an unsafe condition may exist on certain Dornier Model 328-100 series airplanes. The LBA advises that two conditions may lead to the uncommanded unlocking of the ground spoilers. First, a manufacturing defect in a certain batch of relief restrictor valves can lead to internal leakage of hydraulic fluid within the hydraulic components of the ground spoiler system. Second, the design of certain hydraulic components may cause the hydraulic system to be susceptible to the buildup of pressure in the hydraulic return line and in the bypass valve return line. These conditions, if not corrected, could result in the uncommanded unlocking and deployment of the ground spoilers during takeoff or in flight, and consequent reduced controllability of the airplane.
Explanation of Relevant Service Information
Dornier has issued Service Bulletin SB-328-29-220, dated May 20, 1997, and Revision 1, dated May 4, 1998, which describe procedures for performing repetitive tests to detect internal leakage of hydraulic fluid within the hydraulic components of the ground spoiler system and to detect a buildup of pressure in the return line of the bypass valve. These tests include: a major leakage test of the hydraulic components, a functional test of the return filter element, a functional test of the bypass valve of the return filter element, and a functional test of the shutoff valve with the bypass valve.
Dornier has issued Service Bulletin SB-328-29-237, Revision 1, dated December 17, 1997, which describes procedures for installation of additional hydraulic lines and an additional hydraulic shutoff valve in the ground spoiler system.
In addition, Dornier has issued Service Bulletin SB-328-27-243, Revision 1, dated December 18, 1997, which describes procedures for replacement of the relief restrictor valves of the ground spoiler system with redesigned parts, which would eliminate the need for the repetitive tests described previously.
Dornier also has issued Service Bulletin SB-328-27-228, Revision 1, dated December 18, 1997, which describes procedures for replacement of the valve block of the ground spoiler system with a new part. Accomplishment of the actions specified in the service bulletins is
[[Page 39253]]
intended to adequately address the identified unsafe condition. The LBA classified these service bulletins as mandatory and issued German airworthiness directives 97-189, dated June 19, 1997; 1998-031, dated January 15, 1998; 1998-046, dated January 29, 1998; and 1997-331/2, dated March 12, 1998; in order to assure the continued airworthiness of these airplanes in Germany.
FAA's Conclusions
This airplane model is manufactured in Germany and is type certificated for operation in the United States under the provisions 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 operation in the United States.
Explanation of Requirements of Proposed Rule
Since an unsafe condition has been identified that is likely to exist or develop on other airplanes of the same type design registered in the United States, the proposed AD would require accomplishment of the actions specified in the service bulletins described previously, except as discussed below.
Differences Between Proposed Rule and Service Bulletins
Operators should note that Dornier Service Bulletins SB-328-29-220, dated May 20, 1997, and SB-328-29-220, Revision 1, dated May 4, 1998, do not specify corrective action for disposition of certain discrepant conditions. However, if any discrepancy is detected during the testing to detect internal leakage of hydraulic fluid within the hydraulic components of the ground spoiler system and to detect a buildup of pressure in the return line of the bypass valve, this proposal would require, prior to further flight, replacement of the relief restrictor valves of the ground spoiler system with a redesigned part, in accordance with Dornier Service Bulletin SB-328-27-243, Revision 1, dated December 18, 1997.
Cost Impact
The FAA estimates that 11 airplanes of U.S. registry would be affected by this proposed AD.
It would take approximately 3 work hours per airplane to accomplish the proposed tests, at an average labor rate of $60 per work hour. Based on these figures, the cost impact of the tests proposed by this AD on U.S. operators is estimated to be $180 per airplane, per test cycle.
It would take approximately 16 work hours per airplane to accomplish the proposed installation, at an average labor rate of $60 per work hour. Required parts would be supplied by the manufacturer at no cost to operators. Based on these figures, the cost impact of the installation proposed by this AD on U.S. operators is estimated to be $960 per airplane.
It would take approximately 2 work hours per airplane to accomplish the proposed replacement of the relief restrictor valves, at an average labor rate of $60 per work hour. Required parts would be supplied by the manufacturer at no cost to operators. Based on these figures, the cost impact of this replacement proposed by this AD on U.S. operators is estimated to be $120 per airplane.
It would take approximately 2 work hours per airplane to accomplish the proposed replacement of the valve block, at an average labor rate of $60 per work hour. Required parts would be supplied by the manufacturer at no cost to operators. Based on these figures, the cost impact of this replacement proposed by this AD on U.S. operators is estimated to be $120 per airplane.
The cost impact figures discussed above are based on assumptions that no operator has yet accomplished any of the proposed requirements of this AD action, and that no operator would accomplish those actions in the future if this AD were not adopted.
Regulatory Impact
The regulations proposed herein would 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 proposal would not have sufficient federalism implications to warrant the preparation of a Federalism Assessment.
For the reasons discussed above, I certify that this proposed regulation: (1) Is not a ``significant regulatory action'' under Executive Order 12866; (2) is not a ``significant rule'' under the DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); and (3) if promulgated, 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 copy of the draft regulatory evaluation prepared for this action is contained in the Rules Docket. A copy of it may be obtained by contacting 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.
The Proposed Amendment
Accordingly, pursuant to the authority delegated to me by the Administrator, the Federal Aviation Administration proposes to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) as follows:
PART 39--AIRWORTHINESS DIRECTIVES
-
The authority citation for part 39 continues to read as follows:
Authority: 49 U.S.C. 106(g), 40113, 44701.
Sec. 39.13 [Amended]
-
Section 39.13 is amended by adding the following new airworthiness directive:
Dornier Luftfahrt GMBH: Docket 98-NM-140-AD.
Applicability: Model 328-100 series airplanes, certificated in any category, equipped with active ground spoiler option 040-001; as listed in the following service bulletins:
‹bullet› Dornier Service Bulletin SB-328-29-220, Revision 1, dated May 4, 1998;
‹bullet› Dornier Service Bulletin SB-328-29-237, Revision 1, dated December 17, 1997;
‹bullet› Dornier Service Bulletin SB-328-27-243, Revision 1, dated December 18, 1997; and
‹bullet› Dornier Service Bulletin SB-328-27-228, Revision 1, dated December 18, 1997.
Note 1: This AD applies to each airplane 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 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 (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 the ground spoilers from unlocking and deploying during takeoff or in flight, and consequent reduced controllability of the airplane, accomplish the following:
[[Page 39254]]
(a) Prior to the accumulation of 3,000 total flight hours, or within 300 flight hours after the effective date of this AD, whichever occurs later: Perform tests to detect internal leakage of hydraulic fluid within the hydraulic components of the ground spoiler system and to detect a buildup of pressure in the return line of the bypass valve, in accordance with Dornier Service Bulletin SB-328-29-220, dated May 20, 1997, or Dornier Service Bulletin SB-328-29-220, Revision 1, dated May 4, 1998.
(1) If no discrepancy is detected, repeat the tests thereafter at intervals not to exceed 3,000 flight hours, until accomplishment of the replacement required by paragraph (c) of this AD.
(2) If any discrepancy is detected, prior to further flight, accomplish the replacement required by paragraph (c) of this AD.
(b) Install additional hydraulic lines and an additional hydraulic shutoff valve in the ground spoiler system, in accordance with Dornier Service Bulletin SB-328-29-237, Revision 1, dated December 17, 1997, at the applicable time specified in either paragraph (b)(1) or (b)(2) of this AD.
(1) For airplanes having serial numbers up to and including 3086, equipped with ground spoiler actuator, part number 1059A0000- 02: Install within 12 months after the effective date of this AD.
(2) For airplanes having serial numbers up to and including 3086, and equipped with ground spoiler actuator, part number 1059A0000-03: Install within 7 days after the effective date of this AD.
(c) Replace the relief restrictor valves of the ground spoiler system, part number ZRV87-2, with a redesigned valve having part number ZRV87-3, in accordance with Dornier Service Bulletin SB-328- 27-243, Revision 1, dated December 18, 1997, at the applicable time specified in either paragraph (c)(1) or (c)(2) of this AD. Accomplishment of this replacement constitutes terminating action for the repetitive tests required by paragraph (a) of this AD.
(1) For airplanes having serial numbers up to and including 3098, equipped with ground spoiler actuator, part number 1059A0000- 02: Replace within 12 months after the effective date of this AD.
(2) For airplanes having serial numbers up to and including 3098, equipped with ground spoiler actuator, part number 1059A0000- 03: Replace within 7 days after the effective date of this AD.
(d) Replace the valve block of the ground spoiler system with a new part, in accordance with Dornier Service Bulletin SB-328-27-228, Revision 1, dated December 18, 1997, at the applicable time specified in either paragraph (d)(1) or (d)(2) of this AD.
(1) For airplanes having serial numbers up to and including 3095, equipped with ground spoiler actuator, part number 1059A0000- 02: Replace within 12 months after the effective date of this AD.
(2) For airplanes having serial numbers up to and including 3095, equipped with ground spoiler actuator, part number 1059A0000- 03: Replace within 7 days after the effective date of this AD.
(e) As of the effective date of this AD, no person shall install on the ground spoiler system of any airplane, a valve block, part number 1060A0000-05, or a relief restrictor valve, part number ZRV87-2.
(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, 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.
(g) Special flight permits may be issued in accordance with Secs. 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.
Note 3: The subject of this AD is addressed in German airworthiness directives 97-189, dated June 19, 1997; 1998-031, dated January 15, 1998; 1998-046, dated January 29, 1998; and 1997- 331/2, dated March 12, 1998.
Issued in Renton, Washington, on July 15, 1998. Darrell M. Pederson, Acting Manager, Transport Airplane Directorate, Aircraft Certification Service.
[FR Doc. 98-19458Filed7-21-98; 8:45 am]
BILLING CODE 4910-13-P
