Airworthiness Directives; Fokker Model F.27 Mark 050 Series Airplanes

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 99-NM-225-AD; Amendment 39-11379; AD 99-21-33]

RIN 2120-AA64

Airworthiness Directives; Fokker Model F.27 Mark 050 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),

applicable to certain Fokker Model F.27 Mark 050 series airplanes. This

action requires a one-time inspection to detect improper installation

of countersunk screws used to attach the access panels to the bottom

skin of the center wing; and corrective action, if necessary. This

amendment is prompted by issuance of mandatory continuing airworthiness

information by a foreign civil airworthiness authority. The actions

specified in this AD are intended to detect and correct such improper

installation, which could result in fatigue cracking of the bottom skin

of the center wing and consequent reduced structural integrity of the

airplane.

DATES: Effective November 4, 1999.

The incorporation by reference of certain publications listed in

the regulations is approved by the Director of the Federal Register as

of November 4, 1999.

Comments for inclusion in the Rules Docket must be received on or

before November 19, 1999.

ADDRESSES: Submit comments in triplicate to the Federal Aviation

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

Attention: Rules Docket No. 99-NM-225-AD, 1601 Lind Avenue, SW.,

Renton, Washington 98055-4056.

The service information referenced in this AD may be obtained from

Fokker Services B.V., P.O. Box 231, 2150 AE Nieuw-Vennep, The

Netherlands. This information may be examined 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.

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: The Rijksluchtvaartdienst (RLD), which is

the airworthiness authority for the Netherlands, notified the FAA that

an unsafe condition may exist on certain Fokker Model F.27 Mark 050

series airplanes. The RLD advises that, on a number of airplanes on the

production line, the heads of countersunk screws were found not to seat

properly in their countersinkings. The affected screws are used in the

attachment of access panels of the bottom skin of the center wing. This

condition, if not corrected, could result in fatigue cracking of the

bottom skin of the center wing and consequent reduced structural

integrity of the airplane.

Explanation of Relevant Service Information

Fokker has issued Service Bulletin SBF50-57-015, dated February 28,

1996, which describes procedures for a one-time detailed visual

inspection to detect improper installation (excessive gap) of the

countersunk screws in the access covers of the bottom skin of the

center wing.

Fokker has also issued Service Bulletin SBF50-57-018, dated

February 28, 1996, which describes procedures

[[Page 56423]]

for reaming of the fastener holes and an eddy current inspection to

detect cracks in the bottom skin of the center wing. This service

bulletin also describes procedures to repair any cracking that is

found.

The RLD classified these service bulletins as mandatory and issued

Dutch airworthiness directive 1996-042 (A), dated April 29, 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

Sec. 21.29 of the Federal Aviation Regulations (14 CFR 21.19) 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 the 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 detect and correct

improper installation of countersunk screws in the attachment of access

panels of the bottom skin of the center wing, which could result in

fatigue cracking of the bottom skin and consequent reduced structural

integrity of the airplane. This AD requires accomplishment of the

actions specified in the service bulletins described previously.

Differences Between Rule and Service Bulletin

Operators should note that, although Fokker Service Bulletin SBF50-

57-018 specifies that the manufacturer may be contacted for disposition

of certain repair conditions, this AD would require the repair of those

conditions to be accomplished in accordance with a method approved by

the FAA.

Cost Impact

None of the airplanes affected by this action are on the U.S.

Register. All airplanes included in the applicability of this rule

currently are operated by non-U.S. operators under foreign registry;

therefore, they are not directly affected by this AD action. However,

the FAA considers that this rule is necessary to ensure that the unsafe

condition is addressed in the event that any of these subject airplanes

are imported and placed on the U.S. Register in the future.

Should an affected airplane be imported and placed on the U.S.

Register in the future, it would require approximately 6 work hours to

accomplish the required inspection, at an average labor rate of $60 per

work hour. Based on these figures, the cost impact of this AD would be

$360 per airplane.

Determination of Rule's Effective Date

Since this AD action does not affect any airplane that is currently

on the U.S. register, it has no adverse economic impact and imposes no

additional burden on any person. Therefore, prior notice and public

procedures hereon are unnecessary and the amendment may be made

effective in less than 30 days after publication in the Federal

Register.

Comments Invited

Although this action is in the form of a final rule and was not

preceded by notice and 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 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 99-NM-225-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.

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:

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:

99-21-33 Fokker Services B.V.: Amendment 39-11379. Docket 99-NM-

225-AD.

Applicability: Model F.27 Mark 050 series airplanes, serial

numbers 20103 through 20263 inclusive; 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

[[Page 56424]]

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 improper installation of countersunk

screws in the attachment of access panels of the bottom skin of the

center wing, which could result in fatigue cracking of the bottom

skin of the center wing and consequent reduced structural integrity

of the airplane, accomplish the following:

Initial Inspection

(a) Prior to the accumulation of 24,000 total flight cycles,

perform a one-time detailed visual inspection to detect improper

installation (excessive gap) of the countersunk screws used to

attach the access panels to the bottom skin of the center wing, in

accordance with the Accomplishment Instructions of Fokker Service

Bulletin SBF50-57-015, dated February 28, 1996.

Note 2: For the purposes of this AD, a detailed visual

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.''

Inspection and Corrective Action

(b) If any improper installation (excessive gap) is found during

the inspection required by paragraph (a) of this AD: Prior to the

accumulation of 24,000 total flight cycles, ream the fastener holes

in the rabbet of the bottom skin of the center wing and perform an

eddy current inspection for cracking of the fastener holes in

accordance with the Accomplishment Instructions of Fokker Service

Bulletin SBF50-57-018, dated February 28, 1996.

Repair

(1) For any fastener hole for which no crack is found during the

eddy current inspection: Prior to further flight; accomplish

corrective actions for the fastener hole, in accordance with Step C.

of Repair Scheme No. 1 of Fokker Service Bulletin SBF50-57-018,

dated February 28, 1996.

(2) For any fastener hole for which a crack is found during the

eddy current inspection: Prior to further flight; repair and re-

inspect the fastener hole, in accordance with Steps A. and B. of

Repair Scheme No. 1 of Fokker Service Bulletin SBF50-57-018, dated

February 28, 1996. For any crack that is outside the limits

specified in the service bulletin, prior to further flight, repair

in accordance with a method approved by either the Manager,

International Branch, ANM-116, FAA, Transport Airplane Directorate;

or the Rijksluchtvaartdienst (RLD) (or its delegated agent). For a

repair method to be approved by the Manager, International Branch,

ANM-116, as required by this paragraph, the Manager's approval

letter must specifically reference 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 3: 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

Secs. 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) Except as provided by paragraph (b)(2) of this AD, the

actions shall be done in accordance with Fokker Service Bulletin

SBF50-57-015, dated February 28, 1996, and Fokker Service Bulletin

SBF50-57-018, dated February 28, 1996. 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 Fokker Services B.V., P.O. Box 231, 2150 AE Nieuw-

Vennep, The Netherlands. 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 4: The subject of this AD is addressed in Dutch

airworthiness directive 1996-042 (A), dated April 29, 1996.

(f) This amendment becomes effective on November 4, 1999.

Issued in Renton, Washington, on October 8, 1999.

D.L. Riggin,

Acting Manager, Transport Airplane Directorate, Aircraft Certification

Service.

[FR Doc. 99-26933 Filed 10-19-99; 8:45 am]

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