Airworthiness Directives; Dornier Model 328-100 Series Airplanes

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 99-NM-102-AD]

RIN 2120-AA64

Airworthiness Directives; Dornier Model 328-100 Series Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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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 a revision to the FAA-

approved Airplane Flight Manual (AFM) to prohibit in-flight operation

of the auxiliary power unit (APU). This proposal also would require

inspection of the APU fire extinguisher discharge cartridge for

corrosion, and replacement of the discharge cartridge with a new

cartridge, if necessary; and modification of the fire extinguishing

system tube assembly. Accomplishment of these actions would terminate

the AFM revision. This proposal is promoted by issuance of mandatory

continuing airworthiness information by a foreign civil airworthiness

authority. The actions specified by the proposed AD are intended to

detect and correct contamination of the APU fire extinguisher discharge

cartridge, which could result in operational failure of the APU fire

extinguisher.

DATES: Comments must be received by July 28, 1999.

ADDRESSES: Submit comments in triplicate to the Federal Aviation

Administration (FAA), Transport Airplane Directorate, ANM-114,

Attention: Rules Docket No. 99-NM-102-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.

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) 277-1149.

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 filed in 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 99-NM-102-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. 99-NM-102-AD, 1601 Lind Avenue, SW., Renton, Washington

98055-4056.

Discussion

The Luftfahrt-Bundesamt (LBA), which is the airworthiness authority

for Germany, recently notified the FAA that an unsafe condition may

exist on certain Dornier Model 328-100 series airplanes. The LBA

advises that, during maintenance of a Dornier Model 328-100 series

airplane, the auxiliary power unit (APU) fire extinguisher could not be

activated due to contamination of the discharge cartridge with fluids.

The existing design of the fire extinguishing system does not allow for

adequate fluid drainage. This condition, if not corrected, could result

in operational failure of the APU fire extinguisher.

Explanation of Relevant Service Information

Dornier has issued Alert Service Bulletin (ASB-328-26-026, dated

February 1, 1999, which describes procedures for prohibiting in-flight

operation of the APU until accomplishment of an inspection of the APU

fire extinguisher discharge cartridge and modification of the fire

extinguishing system tube assembly. The service bulletin also describes

procedures for inspection of the APU fire extinguisher discharge

cartridge for corrosion, and replacement of the discharge cartridge

with a new cartridge, if necessary; and modification of the fire

extinguishing system tube assembly. The modification involves drilling

a drain hole in the deepest point of the fire extinguishing system tube

assembly. Accomplishment of the actions specified in the Dornier

service bulletin is intended to adequately address the identified

unsafe condition. The LBA classified this service bulletin as mandatory

and issued German airworthiness directive 1999-057, dated February 24,

1999, 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

certified for

[[Page 34591]]

operation in the United States under the provisions of Sec. 21.219 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 this

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 bulletin described previously. The

proposed AD also would require a revision to the Limitations Section of

the FAA-approved Airplane Flight Manual (AFM) to prohibit in-flight

operation of the APU.

Cost Impact

The FAA estimates that 46 airplanes of U.S. registry would be

affected by this proposed AD.

It would take approximately 1 work hour per airplane to accomplish

the proposed revision to the AFM, at an average labor rate of $60 per

work hour. Based on these figures, the cost impact of the AFM revision

proposed by this AD on U.S. operators is estimated to be $2,760, or $60

per airplane.

It would take approximately 1 work hour per airplane to accomplish

the proposed inspection and modification, at an average labor rate is

$60 per work hour. Based on these figures, the cost impact of the

inspection and modification proposed by this AD on U.S. operators is

estimated to be $2,760, or $60 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 ``significantly 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

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

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

Sec. 39.13 [Amended]

2. Section 39.13 is amended by adding the following new

airworthiness directive:

Dornier Luftfahrt GmbH: Docket 99-NM-102-AD.

Applicability: Model 328-100 series airplanes, as listed in

Dornier Alert Service Bulletin ASB-328-26-026, dated February 1,

1999, certificated in any category.

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 (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 detect and correct contamination of the auxiliary power unit

(APU) fire extinguisher discharge cartridge, which could result in

operational failure of the APU fire extinguisher, accomplish the

following:

Airplane Flight Manual Revision

(a) Within 10 days after the effective date of this AD, revise

the Limitations Section of the FAA-approved Dornier 328-100 Airplane

Flight Manual (AFM), Supplement 001, to include the following

statement. This may be accomplished by inserting a copy of this AD

in the AFM.

``In-flight operation of the APU is prohibited.''

Inspection and Modification

(b) Within 2 months after the effective date of this AD,

accomplish the actions specified in paragraphs (b)(1) and (b)(2) of

this AD in accordance with Dornier Alert Service Bulletin ASB-328-

26-026, dated February 1, 1999. After accomplishment of those

actions, the AFM revision required by paragraph (a) of this AD may

be removed, except as provided by paragraph (b)(1)(ii) of this AD.

(1) Inspect the APU fire extinguisher discharge cartridge for

signs of corrosion.

(i) If no corrosion is detected, prior to further flight, clean

and dry the discharge cartridge for re-installation.

(ii) If any corrosion is detected, prior to further flight,

replace the discharge cartridge with a new part; except, if a new

part is not available, the discharge cartridge may be re-installed

and the AFM revision required by paragraph (a) of this AD may NOT be

removed.

(2) Modify the fire extinguishing system tube assembly by

drilling a drain hole.

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.

(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.

Note 3: The inspection, replacement, and modification

requirements of this AD are addressed in German airworthiness

directive 1999-057, dated February 24, 1999.

[[Page 34592]]

Issued in Renton, Washington, on June 22, 1999.

D.L. Riggin,

Acting Manager, Transport Airplane Directorate, Aircraft Certification

Service.

[FR Doc. 99-16327 Filed 6-25-99; 8:45 am]

BILLING CODE 4910-13-U