Airworthiness Directives; Fokker Model F28 Mark 0100 Series Airplanes

DEPARTMENT OF TRANSPORTATION

14 CFR Part 39

[Docket No. 94-NM-113-AD; Amendment 39-9131; AD 95-02-12]

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 fixed engine cowling at the forward and

aft crane beam attachment; and an inspection of the forward and aft

crane beam to detect surface damage, and repair, if necessary. This

amendment is prompted by several reports of rear cabin noise (engine

rumble) during flight and while taxiing, which may have been caused by

the interference between the forward and aft crane beams and the

fasteners in the fixed engine cowling. The actions specified by this AD

are intended to prevent chafing due to normal engine vibration, which

could result in structural damage to the engine mount and possible

separation of the engine from the airplane.

DATES: Effective March 17, 1995.

The incorporation by reference of certain publications listed in

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

of March 17, 1995.

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) 227-1320.

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 F28 Mark 0100

series airplanes was published in the Federal Register on September 30,

1994 (59 FR 49865). That action proposed to require modification of the

fixed cowl at the forward and aft crane-beam attachment; and performing

a visual inspection of the forward and aft crane beam to detect surface

damage, and repair, if necessary.

Interested persons have been afforded an opportunity to participate

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

the comments received.

One commenter supports the proposed rule.

One commenter requests that the proposed 3-month ``grace period''

for compliance be extended to at least two years after the effective

date of this AD for airplanes that are nearing or have exceeded the

threshold of 15,000 flight hours. This commenter states that it would

have to special schedule its fleet of airplanes that are approaching or

have exceeded 15,000 flight hours in order to accomplish the proposed

inspection/modification within the proposed compliance time. This would

entail considerable additional expenses and schedule disruptions.

Additionally, this commenter states that the engines on these airplanes

are changed on an average of every two years and that a two-year

compliance time would allow the proposed inspection/modification to be

accomplished during a regularly scheduled engine change. The two-year

compliance time would eliminate some of the extra down time associated

with the modification. The commenter also states that no in-service

incident exists to warrant such a limited compliance time.

The FAA concurs with the commenter's request. The 3-month ``grace

period'' proposed in the notice was intended to provide additional time

for compliance for those airplanes that are approaching or have

exceeded 15,000 flight hours, without necessarily requiring immediate

compliance (and, thus, grounding of those airplanes). The FAA selected

the 3-month interval specifically as an attempt to provide as

conservative an interval as possible for compliance by the higher time

airplanes; however, it was selected without benefit of any empirical

data or other information from the manufacturer or Dutch airworthiness

authority. Based on the information provided by the commenter, and the

fact that there has been no in-service incident of the subject chafing,

the FAA has determined that a longer ``grace period'' for modification

is reasonable. The FAA has revised paragraph (a) of the final rule to

reflect a ``grace period'' of two years after the effective date of

this AD. This would allow the modification to be accomplished during

regularly scheduled maintenance at a main base, where special equipment

[[Page 8541]] and trained personnel will be available, if necessary.

The FAA does not consider that this extension will adversely affect

safety.

As a result of recent communications with the Air Transport

Association (ATA) of America, the FAA has learned that, in general,

some operators may misunderstand the legal effect of AD's on airplanes

that are identified in the applicability provision of the AD, but that

have been altered or repaired in the area addressed by the AD. The FAA

points out that all airplanes identified in the applicability provision

of an AD are legally subject to the AD. If an airplane has been altered

or repaired in the affected area in such a way as to affect compliance

with the AD, the owner or operator is required to obtain FAA approval

for an alternative method of compliance with the AD, in accordance with

the paragraph of each AD that provides for such approvals. A note has

been added to this final rule to clarify this requirement.

The FAA has recently reviewed the figures it has used over the past

several years in calculating the economic impact of AD activity. In

order to account for various inflationary costs in the airline

industry, the FAA has determined that it is necessary to increase the

labor rate used in these calculations from $55 per work hour to $60 per

work hour. The economic impact information, below, has been revised to

reflect this increase in the specified hourly labor rate.

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 previously

described. The FAA has determined that these changes will neither

increase the economic burden on any operator nor increase the scope of

the AD.

The FAA estimates that 83 airplanes of U.S. registry will be

affected by this AD, that it will take approximately 90 work hours per

airplane to accomplish the required inspection and modification, and

that the average labor rate is $60 per work hour. Required parts will

cost approximately $75 per airplane. Based on these figures, the total

cost impact of the AD on U.S. operators is estimated to be $454,425, or

$5,475 per airplane.

The total 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

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

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. App. 1354(a), 1421 and 1423; 49 U.S.C.

106(g); and 14 CFR 11.89.

39.13 [Amended]

2. Section 39.13 is amended by adding the following new

airworthiness directive:

95-02-12 Fokker: Amendment 39-9131. Docket 94-NM-113-AD.

Applicability: Model F28 Mark 0100 series airplanes, serial

numbers 11244 through 11438 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 repaired so that the performance of the requirements of

this AD is affected, the owner/operator must use the authority

provided in paragraph (b) to request approval from the FAA. This

approval may address either no action, if the current configuration

eliminates the unsafe condition; or different actions necessary to

address the unsafe condition described in this AD. Such a request

should include an assessment of the effect of the changed

configuration on the unsafe condition addressed by this AD. In no

case does the presence of any modification, alteration, or repair

remove any airplane from the applicability of this AD.

Compliance: Required as indicated, unless accomplished

previously. -To prevent structural damage to the engine mount and

possible separation of the engine from the airplane, accomplish the

following:

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

within 2 years after the effective date of this AD, whichever occurs

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

of this AD in accordance with Fokker Service Bulletin SBF100-71-016,

dated February 18, 1994.

(1) Modify the fixed engine cowling at the forward and aft

crane-beam attachment in accordance with the service bulletin.

(2) Perform a visual inspection of the forward and aft crane

beam to detect surface damage, in accordance with the service

bulletin.

(i) If no surface damage is found, no further action is required

by paragraph (a)(2) of this AD.

(ii) If any surface damage is found, prior to further flight,

repair the crane beam in accordance with the service bulletin.

(b) 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.

-(c) 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.

(d) The modification, inspection, and repair shall be done in

accordance with Fokker Service Bulletin SBF100-71-016, dated

February 18, 1994. 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.

(e) This amendment becomes effective on March 17, 1995.

[[Page 8542]] Issued in Renton, Washington, on January 24, 1995.

Darrell M. Pederson,

Acting Manager, Transport Airplane Directorate, Aircraft Certification

Service.

[FR Doc. 95-2175 Filed 2-14-95; 8:45 am]

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