Airworthiness Directives; Fokker Model F28 Mark 0100 Series Airplanes

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 95-NM-58-AD; Amendment 39-9852; AD 96-25-09]

RIN 2120-AA64

Airworthiness Directives; Fokker Model F28 Mark 0100 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 Fokker Model F28 Mark 0100 series airplanes, that

requires modification of the thrust reverser doors, and replacement of

the Collins multifunction display units (MFDU) with new MFDU's. This

amendment also requires installation of a placard if the replacement of

the MFDU is accomplished prior to modification of the thrust reverser

door. This amendment is prompted by a report that cracks were found in

the flanges of the main hinge fittings of the horizontal stabilizer,

which were caused by higher than anticipated loads induced during

thrust reverser operation. The actions specified by this AD are

intended to ensure the structural integrity of the horizontal

stabilizer by reducing the thrust reverser loads on the horizontal

stabilizer.

DATES: Effective January 31, 1997.

The incorporation by reference of certain publications listed in

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

of January 31, 1997.

ADDRESSES: The service information referenced in this AD may be

obtained from Fokker Aircraft USA, Inc., 1199 North Fairfax Street,

Alexandria, Virginia 22314. 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: Tim Dulin, Aerospace Engineer,

Standardization Branch, ANM-113, FAA, Transport Airplane Directorate,

1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (206)

227-2141; fax (206) 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 Fokker Model F28 Mark 0100

series airplanes was published in the Federal Register on December 4,

1995 (60 FR 62051). That action proposed to require modification of the

thrust reverser doors. That action also proposed to require replacement

of certain Collins multifunction display units (MFDU) with certain new

MFDU's, and installation of a placard if the replacement of the MFDU is

accomplished prior to modification of the thrust reverser door.

Interested persons have been afforded an opportunity to participate

in the making of this amendment. Due consideration has been given to

the comments received.

Support for the Proposal

One commenter supports the proposed AD.

Request To Revise Compliance Time

One commenter requests that the compliance time for accomplishing

the modification be revised from the proposed ``prior to the

accumulation of 15,000 total flight cycles or within 1 year after the

effective date of the AD, whichever is later,'' to ``prior to the

accumulation of 16,000 total flight cycles or within 2 years after the

effective date of the AD, whichever is later.'' This commenter states

that the interval for its regular heavy maintenance (``Q'' check) is

expected to be escalated in the near future to 16,000 flight hours/

cycles; if the compliance time of the AD is extended likewise, it will

allow this commenter to modify its fleet of affected airplanes during

this regularly scheduled heavy maintenance interval. The commenter

notes that, since the modification takes approximately 300 work hours

to complete, it would be more economical to accomplish the modification

during regularly scheduled maintenance, rather than having to schedule

special times for the modification to be done. The commenter also

states that, if it were required to bring its airplanes in for

modification at a time other than the ``Q'' check interval, the

associated costs would be far more than what the FAA indicated in its

``cost impact'' information that appeared in the preamble to the

notice. Further, this commenter states that 6 of its 40 affected

airplanes already have gone through their ``Q'' checks without having

the modification installed; and if those 6 airplanes were required to

be modified within 1 year, this commenter would sustain significant

economic and logistical burdens.

The FAA does not concur with the commenter's request. The

compliance time specified in the notice was developed in consultation

with both the Rijksluchtvaartdienst (RLD), which is the airworthiness

authority for the Netherlands, and Fokker. Based on fatigue test

results and analysis of the effects of the thrust reverser loads on

adjacent structure, the FAA has determined that 15,000 flight cycles is

the maximum number of cycles that these airplanes can be allowed to

operate prior to modification without compromising safety. The

commenter has submitted no technical data to justify its request for an

extension of this limit by 1,000 additional flight cycles. Although the

FAA does consider the maintenance schedules of affected operators when

developing appropriate compliance times for AD actions, it does not

revise AD's merely to accommodate individual operators' maintenance

schedules.

Additionally, the FAA disagrees with the commenter's statement that

the modification takes 300 work hours to complete. The cost impact

information that appeared in the preamble to the notice (and in this

final rule, below) indicated that only 127 work hours were necessary to

complete the modification. That figure was based on information

provided by the manufacturer, and was conservatively estimated based on

performing options that take the longest time to accomplish. Further,

the manufacturer estimates that the total elapsed time necessary to

accomplish the modification is only 67 hours, since more than one

person can perform the work.

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 as proposed.

Cost Impact

The FAA estimates that 102 Fokker Model F28 Mark 0100 series

airplanes of U.S. registry will be affected by this AD, that it will

take approximately 127 work hours per airplane to accomplish the

required actions, and that the average labor rate is $60 per work hour.

Required parts will cost approximately $19,000 per airplane. Based on

these figures, the cost impact of the AD on U.S. operators is estimated

to be $2,715,240, or $26,620 per airplane.

The cost impact figure discussed above is based on assumptions that

no operator has yet accomplished any of the requirements of this AD

action, and that no operator would accomplish

[[Page 68132]]

those actions in the future if this AD were not adopted.

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:

96-25-09 Fokker: Amendment 39-9852. Docket 95-NM-58-AD.

Applicability: Model F28 Mark 0100 series airplanes; serial

numbers 11244 through 11460 inclusive, 11463 through 11469

inclusive, 11471, 11474, 11476, 11478, and 11479; 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 (d) 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.

(a) Prior to the accumulation of 15,000 total flight cycles, or

within 1 year after the effective date of this AD, whichever occurs

later, accomplish the requirements of paragraphs (a)(1) and (a)(2)

of this AD concurrently, except as provided by paragraph (b) of this

AD.

(1) Modify the thrust reverser doors in accordance with Fokker

Service Bulletin SBF100-78-010, Revision 1, dated April 26, 1994;

and

(2) Replace the Collins multifunction display units (MFDU)

having part number (P/N) 622-8047-412 or 622-8047-422 with new

MFDU's having P/N 622-8047-414 or 622-8047-423, respectively; as

applicable; in accordance with Fokker Service Bulletin SBF100-31-

036, dated February 7, 1994.

(b) Paragraph (a)(2) of this AD may be accomplished prior to

paragraph (a)(1) of this AD provided that a placard is installed on

the main instrument panel in accordance with Fokker Service Bulletin

SBF100-31-038, dated April 26, 1994, and removed, prior to further

flight, after accomplishment of the requirements of paragraph (a)(1)

of this AD.

(c) For airplanes that have been modified in accordance with

paragraphs (a)(1) and (a)(2) of this AD: No person may install a

Grumman Aerospace aft engine cowling having part number 1159P41440

on any airplane unless it has been previously modified in accordance

with Fokker Component Service Bulletin P41440-78-02, dated December

17, 1993, as revised by Fokker Component Service Bulletin Change

Notification P41440-78-02/001, dated February 25, 1995.

(d) 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.

(e) 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 November 28, 1995.

(f) The actions shall be done in accordance with Fokker Service

Bulletin SBF100-31-036, dated February 7, 1994; Fokker Service

Bulletin SBF100-31-038, dated April 26, 1994; and Fokker Service

Bulletin SBF100-78-010, Revision 1, dated April 26, 1994, which

contains the following list of effective pages:

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Revision level

Page number shown on page Date shown on page

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1-6, 8, 10, 11.................. 1................. April 26, 1994.

7, 9, 12-14..................... Original.......... February 7, 1994.

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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 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.

(g) This amendment becomes effective on January 31, 1997.

Issued in Renton, Washington, on December 5, 1996.

S. R. Miller,

Acting Manager, Transport Airplane Directorate, Aircraft Certification

Service.

[FR Doc. 96-31526 Filed 12-26-96; 8:45 am]

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