[Federal Register Volume 60, Number 228 (Tuesday, November 28, 1995)]
[Proposed Rules]
[Pages 58584-58586]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 95-29012]



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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39

[Docket No. 95-NM-70-AD]


Airworthiness Directives; Fokker Model F27 Mark 050 and Model F28 
Mark 0100 Series Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: This document proposes the adoption of a new airworthiness 
directive (AD) that is applicable to certain Fokker Model F27 Mark 050 
and Model F28 Mark 0100 series airplanes. This proposal would require 
an inspection to verify that adequate clearance exists between the 
insulation screen and the two adjacent terminal bolts, and replacement 
of the circuit breaker terminal bolts with new bolts, if necessary. 
This proposal is prompted by a report that circuit breaker terminal 
bolts that were too long were discovered installed in the circuit 
breaker panels. The actions specified by the proposed AD are intended 
to prevent damage to the insulation screen between adjacent rows of 
circuit breakers, as the result of a circuit breaker terminal bolt 
being too long; this condition could lead to electrical arcing and loss 
of the associated electrical system, which could result in the 
potential for an electrical fire.

DATES: Comments must be received by January 8, 1996.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport 

[[Page 58585]]
Airplane Directorate, ANM-103, Attention: Rules Docket No. 95-NM-70-AD, 
1601 Lind Avenue, SW., Renton, Washington 98055-4056. Comments may be 
inspected at this location between 9:00 a.m. and 3:00 p.m., Monday 
through Friday, except Federal holidays.
    The service information referenced in the proposed rule may be 
obtained from Fokker Aircraft USA, Inc., 1199 North Fairfax Street, 
Alexandria, Virginia 22314. This information may be examined at the 
FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, 
Washington.

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:

Comments Invited

    Interested persons are invited to participate in the making of the 
proposed 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 above. All 
communications received on or before the closing date for comments, 
specified above, will be considered before taking action on the 
proposed rule. The proposals contained in this notice may be changed in 
light of the comments received.
    Comments are specifically invited on the overall regulatory, 
economic, environmental, and energy aspects of the proposed 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 summarizing each FAA-public contact concerned with 
the substance of this proposal will be filed in the Rules Docket.
    Commenters wishing the FAA to acknowledge receipt of their comments 
submitted in response to this notice must submit a self-addressed, 
stamped postcard on which the following statement is made: ``Comments 
to Docket Number 95-NM-70-AD.'' The postcard will be date stamped and 
returned to the commenter.

Availability of NPRMs

    Any person may obtain a copy of this NPRM by submitting a request 
to the FAA, Transport Airplane Directorate, ANM-103, Attention: Rules 
Docket No. 95-NM-70-AD, 1601 Lind Avenue, SW., Renton, Washington 
98055-4056.

Discussion

    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 F27 Mark 050 and Model F28 
Mark 0100 series airplanes. The RLD advises that, during production of 
Fokker Model F27 Mark 050 series airplanes, circuit breaker terminal 
bolts that were too long were installed in the circuit breaker panels. 
Investigation revealed that a design change introduced new circuit 
breaker terminal bolts having hexagonal heads that were too long. These 
new circuit breaker terminal bolts can cause damage to the insulation 
screen between adjacent rows of circuit breakers, which could result in 
electrical arcing; this condition could lead to the loss of the 
associated electrical system and could result in the potential for an 
electrical fire.
    The RLD advises that this unsafe condition also exists on certain 
Model F28 Mark 0100 series airplanes.
    Fokker has issued Service Bulletin SBF100-20-001, dated January 15, 
1994 (for Model F28 Mark 0100 series airplanes), and Service Bulletin 
SBF50-20-003, dated January 11, 1994 (for Model F27 Mark 050 series 
airplanes). These service bulletins describe procedures for a one-time 
inspection to verify that adequate clearance exists between the 
insulation screen and the two adjacent terminal bolts, and replacement 
of the circuit breaker terminal bolts with new bolts, if necessary. The 
RLD classified these service bulletins as mandatory and issued Dutch 
airworthiness directive 94-029 (A), dated February 21, 1994, in order 
to assure the continued airworthiness of these airplanes in the 
Netherlands.
    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.
    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, the proposed AD would require a one-time 
inspection to verify that adequate clearance exists between the 
insulation screen and the two adjacent terminal bolts, and replacement 
of the circuit breaker terminal bolts with new bolts, if necessary. The 
actions would be required to be accomplished in accordance with the 
service bulletins described previously.
    The FAA estimates that 44 Model F28 Mark 0100 series airplanes of 
U.S. registry would be affected by this proposed AD, that it would take 
approximately 1 work hour per airplane to accomplish the proposed 
inspection, and that the average labor rate is $60 per work hour. Based 
on these figures, the cost impact of the proposed inspection on U.S. 
operators of Model F28 Mark 0100 series airplanes is estimated to be 
$2,640, or $60 per airplane.
    Should an operator of Model F28 Mark 0100 series airplanes be 
required to accomplish the necessary bolt replacement, it would take 
approximately 7 work hours per airplane to accomplish the replacement, 
at an average labor rate of $60 per work hour. Required parts would 
cost approximately $100 per airplane. Based on these figures, the cost 
impact of any necessary replacement action is estimated to be $520 per 
airplane.
    The cost impact figure discussed above is based on assumptions that 
no operator has yet accomplished any of the proposed requirements of 
this AD action, and that no operator would accomplish those actions in 
the future if this AD were not adopted.
    Currently there are no Fokker Model F27 Mark 050 series airplanes 
on the U.S. Register. However, should an affected airplane be imported 
and placed on the U.S. Register in the future, it would take 
approximately 1 work hour per airplane to accomplish the proposed 
inspection, at an average labor rate of $60 per work hour. Based on 
these figures, the impact of the proposed inspection on operators of 
Model F27 Mark 050 series airplanes would be $60 per airplane.
    Should an operator of Model F27 Mark 050 series airplanes be 
required to accomplish the necessary bolt replacement, it would take 
approximately 17 work hours per airplane to accomplish the replacement, 
at an average labor rate of $60 per work hour. Required parts would 
cost approximately $150 per airplane. Based on these figures, the cost 
impact of any necessary replacement action is estimated to be $1,170 
per airplane. 

[[Page 58586]]

    The regulations proposed herein would 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 
proposal would not have sufficient federalism implications to warrant 
the preparation of a Federalism Assessment.
    For the reasons discussed above, I certify that this proposed 
regulation (1) is not a ``significant regulatory action'' under 
Executive Order 12866; (2) is not a ``significant rule'' under the DOT 
Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); 
and (3) if promulgated, 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 copy of the draft 
regulatory evaluation prepared for this action is contained in the 
Rules Docket. A copy of it may be obtained by contacting the Rules 
Docket at the location provided under the caption ADDRESSES.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Safety.

The Proposed Amendment

    Accordingly, pursuant to the authority delegated to me by the 
Administrator, the Federal Aviation Administration proposes to amend 
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 USC 106(g), 40101, 40113, 44701.


Sec. 39.13  [Amended]

    2. Section 39.13 is amended by adding the following new 
airworthiness directive:

Fokker: Docket 95-NM-70-AD.
    Applicability: Model F27 Mark 050 series airplanes having serial 
numbers 20247 through 20292 inclusive, and 20294 through 20297 
inclusive; and Model F28 Mark 0100 series airplanes having serial 
numbers 11390 through 11479 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) of this AD 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 electrical arcing and subsequent loss of the 
associated electrical system, which could result in the potential 
for an electrical fire, accomplish the following:
    (a) Within 12 months after the effective date of this AD, 
perform an inspection to verify if adequate clearance exists between 
the insulation screen and the two adjacent terminal bolts in 
accordance with Fokker Service Bulletin SBF100-20-001, dated January 
15, 1994 (for Model F28 Mark 0100 series airplanes), or Fokker 
Service Bulletin SBF50-20-003, dated January 11, 1994 (for Model F27 
Mark 050 series airplanes), as applicable.
    (1) If adequate clearance is found, no further action is 
required by this AD.
    (2) If inadequate clearance is found, prior to further flight, 
replace the circuit breaker terminal bolts with new bolts in 
accordance with the applicable 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 
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 21, 1995.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 95-29012 Filed 11-27-95; 8:45 am]
BILLING CODE 4910-13-U