[Federal Register Volume 62, Number 68 (Wednesday, April 9, 1997)]
[Proposed Rules]
[Pages 17129-17131]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 97-9015]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 96-NM-113-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 repetitive inspections to 
detect cracking of the support beam of the main landing gear (MLG) 
fairing, and permanent repair of any cracking found. Accomplishment of 
the permanent repair terminates the repetitive inspections. This 
proposal is prompted by reports of cracking of the support beam of the 
MLG fairing. The actions specified by the proposed AD are intended to 
prevent such cracking, which could result in reduced structural 
integrity of the lower part of the MLG fairing, and subsequent 
separation of part of the fairing from the airplane.

DATES: Comments must be received by May 19, 1997.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-103, 
Attention: Rules Docket No. 96-NM-113-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 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: Connie Beane, Aerospace Engineer,

[[Page 17130]]

Standardization Branch, ANM-113, FAA, Transport Airplane Directorate, 
1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (206) 
227-2796; fax (206) 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 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 96-NM-113-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-103, Attention: Rules 
Docket No. 96-NM-113-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 it received reports of cracking of the support beam of the 
main landing gear (MLG) fairing on these airplanes. The cracking was 
found during maintenance of the airplanes. This cracking occurs at 
design-critical locations; the design is not adequate due to severe 
bending of materials at these locations. Cracking of the support beam 
of the MLG fairing, if not corrected, could result in reduced 
structural integrity of the lower part of the MLG fairing, and 
subsequent separation of part of the fairing from the airplane.

Explanation of Relevant Service Information

    Dornier has issued Alert Service Bulletin ASB-328-53-010, dated 
October 13, 1995, which describes procedures for repetitive visual 
inspections 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. 
The alert service bulletin also describes procedures for a temporary 
repair (for cracking within specified limits) and a permanent repair 
(for cracking outside specified limits). The temporary repair entails 
stop drilling the crack, and performing subsequent visual inspections 
until the permanent repair is accomplished, or until results of the 
visual inspections reveal that the length of the crack has increased to 
more than 50 mm. Among other things, the permanent repair involves wet 
installing and sealing the angle, protecting reworked surfaces, and 
reworking the existing flange. Accomplishment of the permanent repair 
eliminates the need for the repetitive inspections. The LBA classified 
this alert service bulletin as mandatory and issued German 
airworthiness directive 95-413, dated November 2, 1995, 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 
Sec. 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, the 
proposed AD would require repetitive visual inspections 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, and permanent repair 
of any cracking found. The actions would be required to be accomplished 
in accordance with the alert service bulletin described previously.

Differences Between Alert Service Bulletin and This Proposed AD

    Operators should note that, while the alert service bulletin 
recommends accomplishment of a temporary repair for cracking within 
specified limits, and a permanent repair for cracking outside those 
limits, this proposed AD would require that the permanent repair be 
accomplished for airplanes on which cracking of any length is found. 
The FAA has determined that, due to the safety implications and 
consequences associated with such cracking, the permanent repair must 
be accomplished prior to further flight on all beams that are found to 
be cracked.

Cost Impact

    The FAA estimates that 27 Dornier Model 328-100 series airplanes of 
U.S. registry would be affected by this proposed AD, that it would take 
approximately 1 work hour per airplane to accomplish the proposed 
actions, and that the average labor rate is $60 per work hour. Based on 
these figures, the cost impact of the proposed AD on U.S. operators is 
estimated to be $1,620, or $60 per airplane.
    The cost impact figure discussed above is 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.

[[Page 17131]]

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: Docket 96-NM-113-AD.

    Applicability: Model 328-100 series airplanes, excluding serial 
numbers 3006, 3007, and 3010; 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 prevent reduced structural integrity of the lower part of the 
MLG fairing, and subsequent separation of part of the fairing from 
the airplane, accomplish the following:
    (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 main landing gear (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.
    (2) If any cracking is found, prior to further flight, 
accomplish the permanent repair in accordance with the alert service 
bulletin.
    (b) Accomplishment of the permanent repair in accordance with 
Dornier Alert Service Bulletin ASB-328-53-010, dated October 13, 
1995, constitutes terminating action for the repetitive inspections 
required by this AD.
    (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, Standardization Branch, ANM-113, 
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, 
Standardization Branch, ANM-113.

    Note 2: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the Standardization Branch, ANM-113.

    (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.

    Issued in Renton, Washington, on April 2, 1997.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 97-9015 Filed 4-8-97; 8:45 am]
BILLING CODE 4910-13-U