[Federal Register Volume 61, Number 177 (Wednesday, September 11, 1996)]
[Rules and Regulations]
[Pages 47813-47815]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: X96-10911]


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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39

[Docket No. 96-NM-224-AD; Amendment 39-9752; AD 96-19-04]
RIN 2120-AA64


Airworthiness Directives; Fokker Model F28 Mark 1000, 2000, 3000, 
and 4000 Series Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule; request for comments.

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SUMMARY: This amendment adopts a new airworthiness directive (AD) that 
is applicable to certain Fokker Model F28 Mark 1000, 2000, 3000, and 
4000 series airplanes. This action requires a one-time inspection to 
detect cracks of the dimpled lap joints in the fuselage skin, and 
repair of cracked lap joints. This amendment is prompted by a report 
indicating that cracks were found at various locations in the outer 
skin of the dimpled longitudinal lap joints of the fuselage skin. The 
actions specified in this AD are intended to prevent such cracking, 
which could result in reduced structural integrity of the fuselage and/
or rapid decompression of the airplane.

DATES: Effective September 26, 1996. The incorporation by reference of 
Fokker Service Bulletin F28/53-144, dated July 15, 1996, as listed in 
the regulations is approved by the Director of the Federal Register as 
of September 26, 1996.
    The incorporation by reference of Fokker Service Bulletin F28/53-
121, Revision 1, dated December 13, 1991, as listed in the regulations, 
was approved previously by the Director of the Federal Register as of 
October 8, 1992 (57 FR 40311, September 3, 1992).
    Comments for inclusion in the Rules Docket must be received on or 
before November 12, 1996.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-103, 
Attention: Rules Docket No. 96-NM-224-AD, 1601 Lind Avenue SW., Renton, 
WA 98055-4056.
    The service information referenced in this AD may be obtained from 
Fokker Aircraft USA, Inc., 1199 North Fairfax Street, Alexandria, VA 
22314. This

[[Page 47814]]

information may be examined at the FAA, Transport Airplane Directorate, 
1601 Lind Avenue SW., Renton, WA; or at the Office of the Federal 
Register, 800 North Capitol Street NW., Suite 700, Washington, DC.

FOR FURTHER INFORMATION CONTACT: Tim Dulin, Aerospace Engineer, 
Standardization Branch, ANM-113, FAA, Transport Airplane Directorate, 
1601 Lind Avenue SW., Renton, WA 98055-4056; telephone (206) 227-2141; 
fax (206) 227-1149.

SUPPLEMENTARY INFORMATION: The Rijksluchtvaartdienst (RLD), which is 
the airworthiness authority for the Netherlands, recently notified the 
FAA that an unsafe condition may exist on certain Fokker Model F28 Mark 
1000, 2000, 3000, and 4000 series airplanes. The RLD advises that it 
recently received a report indicating that, during a walk-around 
inspection of a Model F28 Mark 4000 series airplane, two cracks were 
found in the outer skin of the left- and right-hand dimpled 
longitudinal lap joints of the fuselage skin between stations 15263 and 
15733, stringers 16 and 17, and stringers 58 and 59. These cracks were 
approximately 20 inches long. The exact cause of such cracking is 
unknown at this time.
    Currently, AD 93-13-04, amendment 39-8617 (58 FR 38513, July 19, 
1993) requires inspection of these airplanes in the area where the 
recent cracking was found. The inspection is required to be 
accomplished in accordance with Item 53-30-08 of the Fokker Structural 
Integrity Program (SIP) Document 28438. AD 93-13-04 requires that the 
inspection be accomplished by the time that the airplane has 
accumulated 32,000 total flight cycles, and that it be repeated 
thereafter at intervals not to exceed 2,700 flight cycles. However, the 
subject cracking was found on the affected airplane some 3,520 flight 
cycles before the airplane had reached inspection threshold of 32,000 
flight cycles.
    In addition, AD 92-19-02, amendment 39-8359 (57 FR 40311, September 
3, 1992), requires modification of the subject area in accordance with 
Fokker Service Bulletin F28/53-121, prior to the accumulation of 32,000 
flight cycles. However, the affected airplane had accumulated only 
28,480 total flight cycles; therefore, it had not been modified in 
accordance with that AD at the time cracking was detected.
    Cracking in the outer skin of the left- and right-hand dimpled 
longitudinal lap joints of the fuselage skin between stations 15263 and 
15733, stringers 16 and 17, and stringers 58 and 59, if not corrected, 
could result in reduced structural integrity of this area of the 
fuselage and/or rapid decompression of the airplane.
    The configuration of the subject area on Fokker Model Mark 1000, 
2000, and 3000 series airplanes is identical to that on the affected 
Model Mark 4000 series airplane. Therefore, all of these models may be 
subject to this same unsafe condition.

Explanation of Relevant Service Information

    Fokker has issued Service Bulletin F28/53-144, dated July 15, 1996. 
This service bulletin describes procedures for a one-time low frequency 
eddy current inspection to detect cracks of the dimpled lap joints in 
the fuselage skin between stringers 16 and 17, stringers 58 and 59, and 
frames 13345 and 14285. It also describes procedures for submitting a 
report of the inspection results to Fokker.
    Fokker also has issued Service Bulletin F28/53-121, Revision 1, 
dated December 13, 1991, which describes procedures for repair of 
cracked dimpled lap joints. The repair consists of cutting out the lap 
joint and installing a repair plate and shim on the outside of the 
fuselage. The repair will minimize the possibility of cracks developing 
in the subject area of the fuselage.
    The RLD classified these service bulletins as mandatory and issued 
Dutch airworthiness directive BLA 1996-081 (A), dated July 24, 1996, in 
order to assure the continued airworthiness of these airplanes in the 
Netherlands.

FAA's Conclusions

    This airplane model is manufactured in the Netherlands 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 RLD has kept the FAA informed of 
the situation described above. The FAA has examined the findings of the 
RLD, 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 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, this AD is being issued to prevent cracking in 
the subject area of the fuselage skin, which could result in reduced 
structural integrity of the fuselage and/or rapid decompression of the 
airplane. This AD requires a one-time low frequency eddy current 
inspection to detect cracks of the dimpled lap joints in the fuselage 
skin between stringers 16 and 17, stringers 58 and 59, and frames 13345 
and 14285; and repair, if necessary. After accomplishing the 
inspection, the AD also requires operators to submit a report of the 
inspection results to Fokker. The actions are required to be 
accomplished in accordance with the service bulletins described 
previously.

Interim Action

    This is considered to be interim action. The inspection reports 
that are required by this AD will enable the manufacturer to obtain 
better insight into the nature, cause, and extent of cracking; and 
eventually to determine if additional corrective action is necessary to 
address the unsafe condition. Once final action has been identified, 
the FAA may consider further rulemaking.

Determination of Rule's Effective Date

    Since a situation exists that requires the immediate adoption of 
this regulation, it is found that notice and opportunity for prior 
public comment hereon are impracticable, and that good cause exists for 
making this amendment effective in less than 30 days.

Comments Invited

    Although this action is in the form of a final rule that involves 
requirements affecting flight safety and, thus, was not preceded by 
notice and an opportunity for public comment, comments are invited on 
this rule. Interested persons are invited to comment on this 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 under the caption ADDRESSES. All 
communications received on or before the closing date for comments will 
be considered, and this rule may be amended in light of the comments 
received. Factual information that supports the commenter's ideas and 
suggestions is extremely helpful in evaluating the effectiveness of the 
AD action and determining whether additional rulemaking action would be 
needed.
    Comments are specifically invited on the overall regulatory, 
economic, environmental, and energy aspects of the rule that might 
suggest a need to modify the rule. All comments

[[Page 47815]]

submitted will be available, both before and after the closing date for 
comments, in the Rules Docket for examination by interested persons. A 
report that summarizes each FAA-public contact concerned with the 
substance of this AD will be filed in the Rules Docket.
    Commenters wishing the FAA to acknowledge receipt of their comments 
submitted in response to this rule must submit a self-addressed, 
stamped postcard on which the following statement is made: ``Comments 
to Docket Number 96-NM-224-AD.'' The postcard will be date stamped and 
returned to the commenter.

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.
    The FAA has determined that this regulation is an emergency 
regulation that must be issued immediately to correct an unsafe 
condition in aircraft, and that it is not a ``significant regulatory 
action'' under Executive Order 12866. It has been determined further 
that this action involves an emergency regulation under DOT Regulatory 
Policies and Procedures (44 FR 11034, February 26, 1979). If it is 
determined that this emergency regulation otherwise would be 
significant under DOT Regulatory Policies and Procedures, a final 
regulatory evaluation will be prepared and placed in the Rules Docket. 
A copy of it, if filed, 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:

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:

    96-19-04  Fokker: Amendment 39-9752. Docket 96-NM-224-AD.

    Applicability: Model F28 Mark 1000, 2000, 3000, and 4000 series 
airplanes, serial numbers 11017 through 11241 inclusive; on which 
Fokker Service Bulletin F28/53-121, Revision 1, dated December 13, 
1991, has not 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 
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 cracking of the fuselage skin, which could result in 
reduced structural integrity of the fuselage and/or rapid 
decompression of the airplane, accomplish the following:
    (a) Within 60 days after the effective date of this AD, perform 
a one-time low frequency eddy current inspection to detect cracks of 
the dimpled lap joints in the fuselage skin between stringers 16 and 
17, stringers 58 and 59, and frames 13345 and 14285, in accordance 
with Fokker Service Bulletin F28/53-144, dated July 15, 1996.
    (1) If no crack is detected, no further action is required by 
this paragraph.
    (2) If any crack is detected, prior to further flight, repair 
the affected lap joint in accordance with Fokker Service Bulletin 
F28/53-121, Revision 1, dated December 13, 1991. Accomplishment of 
the repair is considered acceptable for compliance with AD 92-19-02, 
amendment 39-8359 (57 FR 40311, September 3, 1992), and constitutes 
terminating action for the inspection identified as item 53-30-08 of 
the Fokker structural integrity program, which is required by AD 93-
13-04, amendment 39-8617 (58 FR 38513, July 17, 1993).
    (b) Within 10 days after accomplishing the inspection required 
by paragraph (a) of this AD, submit a report of the inspection 
results (both positive and negative findings) to Fokker Services, 
ATTN: Manager Service Engineering Jet Aircraft, P.O. Box 75047, 1117 
ZN, Schiphol, The Netherlands. Information collection requirements 
contained in this regulation have been approved by the Office of 
Management and Budget (OMB) under the provisions of the Paperwork 
Reduction Act of 1980 (44 U.S.C. 3501 et seq.) and have been 
assigned OMB Control Number 2120-0056.
    (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.
    (e) The inspection shall be done in accordance with Fokker 
Service Bulletin F28/53-144, dated July 15, 1996. The replacement 
shall be done in accordance with Fokker Service Bulletin F28/53-121, 
Revision 1, dated December 13, 1991. The incorporation by reference 
of Fokker Service Bulletin F28/53-144, dated July 15, 1996, is 
approved by the Director of the Federal Register in accordance with 
5 U.S.C. 552(a) and 1 CFR part 51. The incorporation by reference of 
Fokker Service Bulletin F28/53-121, Revision 1, dated July 15, 1996, 
was approved previously by the Director of the Federal Register in 
accordance with 5 U.S.C. 552(a) and 1 CFR part 51 as of October 8, 
1992 (57 FR 40311, September 3, 1992. Copies may be obtained from 
Fokker Aircraft USA, Inc., 1199 North Fairfax Street, Alexandria, 
Virginia 22314. 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.
    (f) This amendment becomes effective on September 26, 1996.

    Issued in Renton, Washington, on September 3, 1996.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 96- 22917 Filed 9-10-96; 8:45 am]
BILLING CODE 4910-13-U