[Federal Register Volume 64, Number 169 (Wednesday, September 1, 1999)]
[Rules and Regulations]
[Pages 47651-47653]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 99-22390]


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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.

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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

[[Page 47652]]

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:

[[Page 47653]]

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:

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. 99-22390 Filed 8-31-99; 8:45 am]
BILLING CODE 4910-13-M