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Proposed Rule

Airworthiness Directives; Dornier Model 328-100 Series Airplanes

Document Details

Information about this document as published in the Federal Register.

Published Document

This document has been published in the Federal Register. Use the PDF linked in the document sidebar for the official electronic format.

Start Preamble

AGENCY:

Federal Aviation Administration, DOT.

ACTION:

Notice of proposed rulemaking (NPRM).

SUMMARY:

This document proposes the supersedure of an existing airworthiness directive (AD), applicable to all Dornier Model 328-100 series airplanes, that currently requires certain revisions to the airplane flight manual, replacement of certain de-icing boots in the air intake duct assemblies of the engine with re-designed units, repetitive inspections of the boots to find discrepancies, and corrective action if necessary. This action would also require modification of the engine air inlet de-icing system. This action would extend the repetitive inspection interval required by the existing AD, and would add repetitive debonding/delamination and leakage inspections of the de-icing boots, and corrective action if necessary. Initiation of the extended repetitive inspections and new repetitive inspections would end the repetitive inspections required by the existing AD. The actions specified by the proposed AD are intended to prevent engine malfunction due to failure of the engine air inlet de-icing system, which could result in reduced controllability of the airplane. This action is intended to address the identified unsafe condition.

DATES:

Comments must be received by May 3, 2004.

ADDRESSES:

Submit comments in triplicate to the Federal Aviation Administration (FAA), Transport Airplane Directorate, ANM-114, Attention: Rules Docket No. 2002-NM-294-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056. Comments may be inspected at this location between 9 a.m. and 3 p.m., Monday through Friday, except Federal holidays. Comments may be submitted via fax to (425) 227-1232. Comments may also be sent via the Internet using the following address: 9-anm-nprmcomment@faa.gov. Comments sent via fax or the Internet must contain “Docket No. 2002-NM-294-AD” in the subject line and need not be submitted in triplicate. Comments sent via the Internet as attached electronic files must be formatted in Microsoft Word 97 or 2000 or ASCII text.

The service information referenced in the proposed rule may be obtained from AvCraft Aerospace 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.

Start Further Info

FOR FURTHER INFORMATION CONTACT:

Tom Groves, Aerospace Engineer, International Branch, ANM-116, FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (425) 227-1503; fax (425) 227-1149.

End Further Info End Preamble Start Supplemental Information

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 action may be changed in light of the comments received.

Submit comments using the following format:

  • Organize comments issue-by-issue. For example, discuss a request to change the compliance time and a request to change the service bulletin reference as two separate issues.
  • For each issue, state what specific change to the proposed AD is being requested.
  • Include justification (e.g., reasons or data) for each request.

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 filed in the Rules Docket.

Commenters wishing the FAA to acknowledge receipt of their comments Start Printed Page 17098submitted in response to this action must submit a self-addressed, stamped postcard on which the following statement is made: “Comments to Docket Number 2002-NM-294-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. 2002-NM-294-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056.

Discussion

On March 14, 1995, the FAA issued AD 95-04-51, amendment 39-9179 (60 FR 15037, March 22, 1995), applicable to all Dornier Model 328-100 series airplanes, to require certain revisions to the airplane flight manual (AFM), replacement of certain de-icing boots in the air intake duct assemblies of the engine with re-designed units, and inspections of the boots to find discrepancies. That action was prompted by reports of failures of the engine air inlet de-icing system, including debonding of the boots from the engine air intake ducts, failure of the air-tight chambers in the boots, and malfunction and subsequent shutdown of an engine during flight. The requirements of that AD are intended to prevent engine malfunction due to failure of the engine air inlet de-icing system.

Actions Since Issuance of Previous Rule

In the preamble to AD 95-04-51, we specified that the actions required by that AD were considered to be “interim action” and that we may consider further rulemaking action. The manufacturer now has developed an improved modification of the engine air inlet de-icing system. We have determined that further rulemaking is necessary to require the modification on affected airplanes; this proposed AD follows from that determination.

Explanation of New Service Information

The manufacturer has issued the following Dornier Service Bulletins:

  • SB-328-71-122, Revision 1, dated May 10, 1999, which describes procedures for the modification of the engine air intake ducts. The service bulletin references Westland Aerospace Limited Service Bulletin SB-WAL328-71-122, dated September 25, 1995, as an additional source of service information for accomplishment of the modification.
  • SB-328-71-125, Revision 3, dated May 10, 1999, which describes procedures for modification of the engine air inlet de-icing system, which includes installation of new, improved engine air intake ducts, installation of geometrically adapted de-icing boots, and installation of an improved outlet cover plate of the bypass duct. The service bulletin also describes procedures for doing detailed visual and tactile inspections of certain de-icing boots for discrepancies (flat spots, softness, or other irregularities in concave sections, or improper sealing), and corrective action if discrepancies are found. The corrective action includes doing a debonding inspection, as specified in the airplane maintenance manual, and if the debonded area is outside the allowable limits, replacing all three de-icing boots before further flight.

Dornier Service Bulletin SB-328-71-125, Revision 3, also references Westland Aerospace Limited Service Bulletin SB-WAL328-71-125, Revision 1, dated September 25, 1995, as an additional source of service information for installation of the cover plate of the bypass duct outlet.

  • SB-328-30-432, dated April 26, 2002, which describes procedures for doing detailed visual and tactile inspections of the engine air inlet de-icing boots to find discrepancies (flat or soft spots in concave sections, defects on the de-icing boots, or improper sealing), and corrective action if discrepancies are found. The corrective action includes doing a debonding/delamination and leakage inspection, and replacing any delaminated de-icing boot outside the allowable bonding limits. The inspections are to be repeated thereafter at certain intervals.

The Luftfahrt-Bundesamt (LBA), which is the airworthiness authority for Germany, classified the Dornier service information as mandatory and issued German airworthiness directives 1995-156/3, dated July 1, 1999; and 2002-256, dated September 5, 2002, to ensure 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 us informed of the situation described above. We have 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 supersede AD 95-04-51 to continue to require the revisions to the AFM, replacement of certain de-icing boots in the air intake duct assemblies of the engine with re-designed units, and repetitive inspections of the boots to find discrepancies, and corrective action if necessary. This action also would require modification of the engine air inlet de-icing system and would add a new AFM revision which changes the compliance time for the functional test required by the existing AD. It would also extend the repetitive inspection interval required by the existing AD, and would add repetitive debonding/delamination and leakage inspections of the de-icing boots, and corrective action if necessary. Initiation of the extended repetitive inspections and debonding/delamination and leakage inspections would end the repetitive inspections required by the existing AD. The actions would be required to be accomplished in accordance with the Dornier service bulletins described previously, except as discussed below.

Differences Among German Airworthiness Directives, Dornier Service Bulletins, and Proposed AD

The German airworthiness directives do not contain a requirement for continued accomplishment of the functional test required by the existing AD, but this proposed AD does continue to require accomplishment of the functional test.

German airworthiness directive 2002-256 and Service Bulletin SB-328-30-432 specify a repetitive interval of 800 flight hours for the detailed inspection and a debonding/delamination and leakage inspection of the engine air intake de-icing system specified in paragraph 2.B.2. of the service bulletin. We have determined that, since paragraph 2.B.1.(1) of the service bulletin specifies the same detailed inspection at a 60-flight-hour interval, it is not necessary to also require the detailed inspection at the 800-flight-hour interval.

In addition, this proposed AD would require accomplishment of the debonding/delamination and leakage inspection described in paragraph 2.B.2.(2) of the service bulletin at intervals not to exceed 400 flight hours, Start Printed Page 17099in lieu of every 800 flight hours. We have reviewed the service history of the U.S.-registered fleet of Model 328-100 series airplanes and have found that an 800-flight-hour debonding/delamination and leakage inspection interval would not be sufficient to find progressive inlet boot delamination/debonding before it reaches a point where it represents a hazard to the airplane. In developing an appropriate compliance time for this action, we considered not only the safety implications and the LBA recommendations, but the manufacturer's recommendation and the degree of urgency associated with addressing the subject unsafe condition. In light of all of these factors, we find an initial compliance time of “within 400 flight hours after the effective date of this AD,” and repetitive intervals not to exceed 400 flight hours after the initial inspection, for doing the proposed debonding/delamination and leakage inspections to be warranted, in that those times represent appropriate intervals of time allowable for affected airplanes to continue to operate without compromising safety.

Although Service Bulletin SB-328-30-432 defines the inspection as “visual” and “touch,” and SB-328-71-125 defines the inspection as “detailed visual” and “tactile,” this proposed AD defines that inspection as a “detailed” inspection. In addition, we have changed all references to a “detailed visual inspection” in the existing AD to “detailed inspection” in this proposed AD. A new note has been added to the proposed AD to define this inspection.

German airworthiness directive 1995-156/3 and Service Bulletin SB-328-71-125 recommend modification of the air intake/de-icing system “not later than December 31, 1995,” and “weekly” visual and tactile inspections. This proposed AD would require the modification within 60 flight hours after the effective date of this AD. When German airworthiness directive 1995-156/2 was issued on November 2, 1995, we did not take parallel action because we had previously issued an alternative method of compliance for the existing AD which approved the modification of the air intake/de-icing system. We are now requiring the modification on all airplanes that have not yet been modified.

In addition, although “weekly” visual and tactile inspections are specified in the German airworthiness directive and Service Bulletin SB-328-71-125, this proposed AD would require only a one-time inspection after accomplishment of the modification, then repetitive detailed inspections at intervals not to exceed 60 flight hours and debonding/delamination and leakage inspections at intervals not to exceed 400 flight hours, per the procedures specified in Service Bulletin SB-328-30-432.

Service Bulletin SB-328-30-432 describes procedures for completing a reporting sheet with inspection results, but this proposed AD does not include such a requirement.

Work Hour Rate Increase

We have reviewed the figures we have used over the past several years to calculate AD costs to operators. To account for various inflationary costs in the airline industry, we find it necessary to increase the labor rate used in these calculations from $60 per work hour to $65 per work hour. The cost impact information, below, reflects this increase in the specified hourly labor rate.

Cost Impact

There are about 53 airplanes of U.S. registry that would be affected by this proposed AD.

The AFM revision currently required by AD 95-04-51 takes about 1 work hour per airplane to accomplish, at an average labor rate of $65 per work hour. Based on these figures, the cost impact of the currently required AFM revision is estimated to be $65 per airplane.

The inspections currently required by AD 95-04-51 take about 1 work hour per airplane to accomplish, at an average labor rate of $65 per work hour. Based on these figures, the cost impact of the currently required inspections are estimated to be $65 per airplane, per inspection cycle.

The replacement currently required by AD 95-04-51 takes about 5 work hours per airplane to accomplish, at an average labor rate of $65 per work hour. Required parts will cost about $55,000 per airplane. Based on these figures, the cost impact of the currently required replacement is estimated to be $55,325 per airplane.

The modification proposed in this AD action would take about 10 work hours per airplane to accomplish, at an average labor rate of $65 per work hour. Required parts would be free of charge. Based on these figures, the cost impact of the proposed modification on U.S. operators is estimated to be $34,450, or $650 per airplane.

The inspection/debonding/delamination and leakage inspection proposed in this AD action would take about 1 work hour per airplane to accomplish, at an average labor rate of $65 per work hour. Based on these figures, the cost impact of the proposed inspection on U.S. operators is estimated to be $3,445, or $65 per airplane, per inspection cycle.

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. The cost impact figures discussed in AD rulemaking actions represent only the time necessary to perform the specific actions actually required by the AD. These figures typically do not include incidental costs, such as the time required to gain access and close up, planning time, or time necessitated by other administrative actions.

Regulatory Impact

The regulations proposed herein 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. Therefore, it is determined that this proposal would not have federalism implications under Executive Order 13132.

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.

Start List of Subjects

List of Subjects in 14 CFR Part 39

End List of Subjects

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:

Start Part

PART 39—AIRWORTHINESS DIRECTIVES

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

Start Authority

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

End Authority
Start Printed Page 17100
[Amended]

2. Section 39.13 is amended by removing amendment 39-9179 (60 FR 15037, March 22, 1995), and by adding a new airworthiness directive (AD), to read as follows:

Fairchild Dornier GmbH (Formerly Dornier Luftfahrt GmbH): Docket 2002-NM-294-AD. Supersedes AD 95-04-51, Amendment 39-9179.

Applicability: All Model 328-100 airplanes, certificated in any category.

Compliance: Required as indicated, unless accomplished previously.

To prevent engine malfunction due to failure of the engine air inlet de-icing system, which could result in reduced controllability of the airplane, accomplish the following:

Restatement of Certain Requirements of AD 95-04-01

AFM Revision

(a) For all airplanes: Within 24 hours after April 6, 1995 (the effective date of AD 95-04-51, amendment 39-9179), accomplish paragraphs (a)(1), (a)(2), and (a)(3) of this AD.

(1) Revise the Limitations Section of the FAA-approved Airplane Flight Manual (AFM) by inserting the following limitation in the AFM. This may be accomplished by inserting a copy of this AD in the AFM.

“During flight, if the ‘ENG DEICE FAIL' electronic indication and caution advisory system (EICAS) annunciation activates for either engine, flight into known or forecast icing conditions is prohibited.”

(2) Revise the Abnormal Procedures Section of the FAA-approved AFM by removing page 4, dated September 1, 1994, of section 04-12-00, and replacing it with the following. This may be accomplished by inserting a copy of this AD in the AFM.

“1. Icing ConditionsExit immediately.
If unable, land at nearest suitable airport.”

(3) Revise the Limitations Section of the FAA-approved AFM to include the following functional test. This may be accomplished by inserting a copy of this AD in the AFM. Continue to do the functional test until the AFM revision required by paragraph (e) of this AD is done.

“Accomplish the following test at the applicable time specified as follows:

For airplanes equipped with air intake duct assemblies having de-icing boots with part numbers (P/N's) 29S-5D5240-21, -23, and -25: As of 24 hours after the effective date of AD 95-04-51, accomplish the functional test prior to each flight.

For airplanes equipped with air intake duct assemblies having de-icing boots with P/N's 29S-5D5240-211 (inlet lip), -231 (bypass duct), and -251 (aft ramp duct): Accomplish the functional test within 24 hours after the effective date of AD 95-04-51, and thereafter at daily intervals.

Perform a functional test of the de-icing system of the air intake ducts of the left and right engines to determine the condition of the system, in accordance with the procedures specified below. Flight crew or maintenance personnel shall perform this test.

FUNCTIONAL TEST OF THE DE-ICING SYSTEM

With engines running at idle power, display and monitor the ‘ICE PROTECT’ system page of the electronic indication and caution advisory system (EICAS), select left and right ‘ENGINE INTAKE' pushbuttons in (‘ON'), for a minimum of 60 seconds. Monitor system page for normal indications of one complete boot inflation and deflation cycle. Monitor EICAS for normal messages, and absence of ‘ENG DEICE FAIL' caution.

After 60 seconds and observation of one complete inflation/deflation cycle, release ‘ENGINE INTAKE' pushbuttons to out (‘OFF') position, confirm absence of system page and EICAS cautions, and deselect ‘ICE PROTECT' system page. At completion of check, ‘ENGINE INTAKE' pushbuttons may be turned back on if required for departure.

If any EICAS ‘ENG DEICE FAIL' annunciation is observed, or if system normal inflate and deflate cycling is not observed: The system shall be considered inoperative. Prior to further flight, the detailed visual and tactile inspections required by paragraph (b) of AD 95-04-51 must be accomplished.

If no discrepancy with the de-icing boots is found during these inspections, the de-icing system may be inoperative for a period of time not to exceed that specified in the DO-328 Master Minimum Equipment List (MMEL). Flight into known or forecast icing conditions is prohibited.”

Repetitive Inspections/Corrective Action

(b) For airplanes equipped with air intake duct assemblies having de-icing boots with part numbers (P/N) 29S-5D5240-21, -23, and -25: Accomplish paragraphs (b)(1) and (b)(2) of this AD at the times specified in those paragraphs.

(1) Within 24 hours after April 6, 1995: Perform a detailed inspection and a tactile inspection of the de-icing boots in the air intake ducts on the engines to find flat spots, softness, or other discrepancies, and to ensure that the edges of the de-icing boots are sealed properly, in accordance with Dornier Service Bulletin SB-328-30-020, dated March 17, 1994.

Note 1:

For the purposes of this AD, a detailed inspection is defined as: “An intensive visual examination of a specific structural area, system, installation, or assembly to detect damage, failure, or irregularity. Available lighting is normally supplemented with a direct source of good lighting at intensity deemed appropriate by the inspector. Inspection aids such as mirror, magnifying lenses, etc., may be used. Surface cleaning and elaborate access procedures may be required.”

(i) If no discrepancies are found and the edges of the de-icing boots are sealed properly (no debonding between the boot and the intake duct), repeat the detailed and tactile inspections required by paragraph (b)(1) of this AD thereafter at daily intervals until accomplishment of the modification required by paragraph (f) of this AD.

(ii) If any discrepancy is found, or if any edge of a de-icing boot is sealed improperly (debonding between the boots and the intake duct), prior to further flight, replace all three de-icing boots having P/Ns 29S-5D5240-21, -23, and -25, with three new units having P/Ns 29S-5D5240-211, -231, and -251, in accordance with the procedures specified in Dornier Alert Service Bulletin ASB-328-71-006, Revision 1, dated February 16, 1995.

(2) Within 5 days after April 6, 1995, replace all three de-icing boots having P/N's 29S-5D5240-21, -23, and -25, with three new units having P/Ns 29S-5D5240-211, -231, and -251, in accordance with Dornier Alert Service Bulletin ASB-328-71-006, Revision 1, dated February 16, 1995. Following such replacement, perform the detailed and tactile inspections and the functional tests required by paragraphs (c) and (e) of this AD, respectively, in accordance with the times and procedures specified in those paragraphs.

(c) For airplanes equipped with air intake duct assemblies having de-icing boots with P/Ns 29S-5D5240-211,-231, and -251: Within 7 days after April 6, 1995, perform a detailed inspection and a tactile inspection of the de-icing boots in the air intake ducts on the engines to find flat spots, softness, or other discrepancies, and to ensure that the edges of the de-icing boots are sealed properly, in accordance with the procedures specified in Dornier Service Bulletin SB-328-30-020, dated March 17, 1994.

(1) If no discrepancies are found and the edges of the de-icing boots are sealed properly (no debonding between the boot and the intake duct): Repeat the detailed and tactile inspections required by paragraph (c) of this AD thereafter at intervals not to exceed 7 days until accomplishment of the modification required by paragraph (f) of this AD.

(2) If any discrepancy is found, or if any edge of a de-icing boot is sealed improperly (debonding between the boots and the intake duct): Prior to further flight, replace all three de-icing boots with three new units having P/Ns 29S-5D5240-211, -231, and -251, in accordance with Dornier Alert Service Bulletin ASB-328-71-006, Revision 1, dated February 16, 1995.

Parts Installation

(d) As of April 6, 1995, no de-icing boot having P/N 29S-5D5240-21, -23, or -25 shall be installed on any airplane.

New Requirements of This Ad

AFM Revision

(e) Within 24 hours after the effective date of this AD: Revise the Limitations Section of the AFM to include the following functional test. This may be accomplished by inserting a copy of this AD into the AFM. Accomplishment of this paragraph ends the requirements of paragraph (a)(3) of this AD, and the AFM revision required by that paragraph may be removed from the AFM.

“Accomplish the following test within 24 hours after the effective date of this AD. Repeat the test thereafter at daily intervals.

Perform a functional test of the de-icing system of the air intake ducts of the left and right engines to determine the condition of the system, in accordance with the procedures specified below. Flight crew or Start Printed Page 17101maintenance personnel shall perform this test.

FUNCTIONAL TEST OF THE DE-ICING SYSTEM

With engines running at idle power, display and monitor the ‘ICE PROTECT’ system page of the electronic indication and caution advisory system (EICAS), select left and right ‘ENGINE INTAKE’ pushbuttons in (‘ON’), for a minimum of 60 seconds. Monitor system page for normal indications of one complete boot inflation and deflation cycle. Monitor EICAS for normal messages, and absence of ‘ENG DEICE FAIL’ caution.

After 60 seconds and observation of one complete inflation/deflation cycle, release ‘ENGINE INTAKE’ pushbuttons to out (‘OFF’) position, confirm absence of system page and EICAS cautions, and deselect ‘ICE PROTECT’ system page. At completion of check, ‘ENGINE INTAKE’ pushbuttons may be turned back on if required for departure.

If any EICAS ‘ENG DEICE FAIL’ annunciation is observed, or if system normal inflate and deflate cycling is not observed: The system shall be considered inoperative. Prior to further flight, the detailed inspections required by paragraph (g) of this AD must be accomplished.

If no discrepancy with the de-icing boots is found during these inspections, the de-icing system may be inoperative for a period of time not to exceed that specified in the DO-328 Master Minimum Equipment List (MMEL). Flight into known or forecast icing conditions is prohibited.”

Modification of the Engine Air Intake De-icing System

(f) Within 60 flight hours after the effective date of this AD: Modify the engine air inlet de-icing system (including a one-time detailed inspection and a debonding/delamination and leakage inspection) by doing all the actions (including any applicable corrective action) per the Accomplishment Instructions of Dornier Service Bulletin SB-328-71-125, Revision 3; and by doing all the actions per the Accomplishment Instructions of Dornier Service Bulletin SB-328-71-122, Revision 1; both dated May 10, 1999. Do any applicable corrective action before further flight per the applicable service bulletin.

Note 2:

The de-icing boots approved for installation on the modified engine inlet assembly are specified in paragraph 3., “Material Information,” of the Accomplishment Instructions of Dornier Service Bulletin SB-328-30-432, dated April 26, 2002.

Note 3:

Dornier Service Bulletin SB-328-71-122, Revision 1, dated May 10, 1999, references Westland Aerospace Limited Service Bulletin SB-WAL328-71-122, dated September 25, 1995, as an additional source of service information for modification of the air intake ducts; and Dornier Service Bulletin SB-328-71-125, Revision 3, dated May 10, 1999, references SB-WAL328-71-125, Revision 1, dated September 25, 1995, as an additional source of service information for installation of the cover plate of the bypass duct outlet.

Repetitive Inspections

(g) Within 60 flight hours after accomplishment of paragraph (f) of this AD: Do a detailed inspection of the engine air inlet de-icing boots to find discrepancies (including flat or soft spots in concave sections, defects on the de-icing boots, or improper sealing), per paragraph 2.B.1. of the Accomplishment Instructions of Dornier Service Bulletin SB-328-30-432, dated April 26, 2002. Do any applicable corrective action before further flight per the service bulletin. Repeat the inspection thereafter at intervals not to exceed 60 flight hours.

(h) Within 400 flight hours after accomplishment of paragraph (f) of this AD: Do a debonding/delamination and leakage inspection of the engine air inlet de-icing boots by doing all the applicable actions per the Accomplishment Instructions of Dornier Service Bulletin SB-328-30-432, dated April 26, 2002. Do any applicable corrective action before further flight per the service bulletin. Repeat the inspection thereafter at intervals not to exceed 400 flight hours.

(i) Initiation of the repetitive inspections required by paragraphs (g) and (h) of this AD terminates the repetitive inspections required by paragraphs (b) and (c) of this AD.

No Reporting Required

(j) Where Dornier Service Bulletin SB-328-30-432, dated April 26, 2002; describes procedures for completing a reporting sheet with inspection results, this AD does not require that action.

Alternative Methods of Compliance

(k)(1) In accordance with 14 CFR 39.19, the Manager, International Branch, ANM-116, FAA, Transport Airplane Directorate, is authorized to approve alternative methods of compliance for this AD.

(2) Alternative methods of compliance, approved previously in accordance with AD 95-04-51, amendment 39-9179, are not considered to be approved as alternative methods of compliance with this AD.

Note 4:

The subject of this AD is addressed in German airworthiness directives 1995-156/3, dated July 1, 1999; and 2002-256, dated September 5, 2002.

Start Signature

Issued in Renton, Washington, on March 26, 2004.

Kalene C. Yanamura,

Acting Manager, Transport Airplane Directorate, Aircraft Certification Service.

End Signature End Part End Supplemental Information

[FR Doc. 04-7303 Filed 3-24-04; 8:45 am]

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