[Federal Register Volume 61, Number 245 (Thursday, December 19, 1996)]
[Rules and Regulations]
[Pages 66890-66892]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 96-31524]


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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39

[Docket No. 96-NM-268-AD; Amendment 39-9850; AD 96-24-10]
RIN 2120-AA64


Airworthiness Directives; Fokker Model F28 Mark 0070 and 0100 
Series Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule; request for comments.

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SUMMARY: This document publishes in the Federal Register an amendment 
adopting airworthiness directive (AD) 96-24-10 that was sent previously 
to all known U.S. owners and operators of Fokker Model F28 Mark 0070 
and 0100 series airplanes by individual notices. This amendment 
supersedes an existing AD, but retains the requirement of that AD to 
incorporate a revision to the Airplane Flight Manual that will enable 
the flightcrew to determine if the thrust reversers are properly stowed 
and locked prior to take-off. This new AD also requires a new revision 
to the maintenance program to incorporate certain instructions related 
to checks of the thrust reverser system. This new AD allows dispatch of 
the airplane, under certain conditions, with both thrust reversers 
inoperative. This action is prompted by results of a review, which 
indicated that a potential latent failure of the secondary lock switch 
1 of the thrust reverser system in the open position may occur, in 
addition to the potential failure of the secondary lock relay 1 in the 
energized position, which was addressed by the existing AD. The actions 
specified by this AD are intended to prevent such failures, which could 
result in reduced protection against inadvertent deployment of the 
thrust reversers during flight.

DATES: Effective December 24, 1996, to all persons except those persons 
to whom it was made immediately effective by emergency AD 96-24-10, 
issued on November 19, 1996, which contained the requirements of this 
amendment.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of December 24, 1996.
    Comments for inclusion in the Rules Docket must be received on or 
before February 18, 1997.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-103, 
Attention: Rules Docket No. 96-NM-268-AD, 1601 Lind Avenue, SW., 
Renton, Washington 98055-4056.
    The applicable service information 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; 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: On November 8, 1996, the FAA issued AD 96-
23-16, amendment 39-9825 (61 FR 5887, November 20, 1996), applicable to 
all Fokker Model F28 Mark 0070 and 0100 series airplanes. That AD:
    1. Requires a revision to the Airplane Flight Manual (AFM) to 
include information that will enable the flightcrew to determine if the 
thrust reversers are properly stowed and locked prior to take-off;
    2. Provides for dispatch of the airplane with both autothrottle 
channels inoperative, provided that both thrust reversers are 
deactivated and secured in the stowed position, and no operations are 
conducted that are predicated on thrust reverser operation; and
    3. Requires revising the maintenance program to provide 
instructions to

[[Page 66891]]

correct malfunctions of the thrust reverser system.
    The requirements of that AD were intended to prevent an 
unannunciated failure of the secondary lock relay 1 of the thrust 
reversers, which could result in reduced protection against inadvertent 
deployment of the thrust reversers during flight.

Actions Since Issuance of Previous AD

    Since the issuance of AD 96-23-16, the Rijksluchtvaartdienst (RLD), 
which is the airworthiness authority for the Netherlands, advises that 
Fokker has conducted an additional review and safety assessment of the 
thrust reverser control and indication system. The results of this 
review indicate that a potential latent failure of the secondary lock 
switch 1 in the open position may occur; this is in addition to the 
potential failure of the secondary lock relay 1 in the energized 
position, which was addressed by AD 96-23-16.
    Failure of the secondary lock switch 1 in the open position could 
prevent or block the automatic signal to command the thrust reversers 
to the stow position when an uncommanded movement of the secondary lock 
actuator occurs.

Explanation of Relevant Service Information

    Fokker has issued All Operator Message TS96.67591, dated November 
14, 1996, including Appendix 1 and Appendix 2. Among other things, the 
All Operator Message describes procedures for performing a daily check 
to detect a latent failure of the secondary lock switch 1. 
Accomplishment of these actions will prevent a latent failure of the 
secondary lock switch 1. The RLD classified the All Operator Message as 
mandatory and issued Netherlands airworthiness directive (BLA) 1996-
138/2 (A), dated November 15, 1996, in order to assure the continued 
airworthiness of these airplanes in the Netherlands.

FAA's Conclusions

    These airplanes model are manufactured in the Netherlands and are 
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 the Requirements of the Rule

    Since the unsafe condition described is likely to exist or develop 
on other airplanes of the same type design registered in the United 
States, the FAA issued emergency AD 96-24-10 to prevent failure of the 
secondary lock relay 1 of the thrust reversers in the energized 
position and secondary lock switch 1 in the open position, which could 
result in reduced protection against inadvertent deployment of the 
thrust reversers during flight. The new AD supersedes AD 96-23-16, but 
continues to require a revision to the Limitations Section of the FAA-
approved AFM to enable the flightcrew to determine if the thrust 
reversers are properly stowed and locked prior to take-off by 
monitoring proper engagement of the autothrottle system (ATS). This new 
AD allows dispatch of the airplane with both thrust reversers 
inoperative, provided they are deactivated and secured in the stowed 
position, and no operations are conducted that are predicated on thrust 
reverser operation. In addition, the new AD requires a new revision to 
the FAA-approved maintenance program to incorporate instructions to 
correct malfunctions of the secondary lock relay 1 of the thrust 
reversers found during the operational tests; to perform a daily check 
to detect latent failure of the secondary lock switch 1; and to take 
corrective actions, if necessary. The revision to the maintenance 
program is required to be accomplished in accordance with Appendix 2 of 
the All Operator Message previously described.
    Since it was found that immediate corrective action was required, 
notice and opportunity for prior public comment thereon were 
impracticable and contrary to the public interest, and good cause 
existed to make the AD effective immediately by individual notices 
issued on November 19, 1996, to all known U.S. owners and operators of 
Fokker Model F28 Mark 0070 and 0100 series airplanes. These conditions 
still exist, and the AD is hereby published in the Federal Register as 
an amendment to section 39.13 of the Federal Aviation Regulations (14 
CFR 39.13) to make it effective as to all persons.

Interim Action

    This AD is considered to be interim action until final action is 
identified, at which time the FAA may consider further rulemaking.

Differences Between This AD and the Related Netherlands BLA

    This AD differs from the Netherlands airworthiness directive (BLA) 
1996-138/2 (A), in the following respects:
    1. This AD allows dispatch with both thrust reversers inoperative, 
provided they are deactivated and stowed, and no operations are 
conducted that are predicated on thrust reverser operation; whereas, 
the Dutch airworthiness directive does not address this issue. The FAA-
approved Master Minimum Equipment List (MMEL) only allows one thrust 
reverser to be inoperative; whereas, the Dutch MMEL allows both thrust 
reversers to be inoperative. Therefore, the FAA finds that the AD must 
include provisions for dispatch of the airplane with both thrust 
reversers deactivated and stowed.
    2. The AD does not allow both autothrottle channels to be 
inoperative; whereas, the Dutch airworthiness directive does permit 
this option, albeit with certain restrictions. The FAA-approved MMEL 
allows only one autothrottle to be inoperative. The FAA finds no 
safety-related reason to change this requirement.
    3. The AD does not allow dispatch of the airplane with an 
inoperative thrust reverser indication and alerting system, which is 
consistent with the FAA-approved MMEL. The Dutch airworthiness 
directive removes this provision from the Dutch MMEL.

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 66892]]

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-268-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.


39.13  [Amended]

    2. Section 39.13 is amended by removing amendment 39-9825 (61 FR 
5887, November 20, 1996), and by adding a new airworthiness directive, 
amendment 39-9850, to read as follows:

96-24-10  Fokker: Amendment 39-9850. Docket 96-NM-268-AD. Supersedes 
AD 96-23-16, amendment 39-9825.

    Applicability: All Model F28 Mark 0070 and 0100 series 
airplanes, 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.
    To prevent reduced protection against inadvertent deployment of 
the thrust reversers during flight, accomplish the following:
    (a) Within 48 hours after November 25, 1996 (the effective date 
of AD 96-23-16, amendment 39-9825), revise the Limitations Section 
of the FAA-approved Airplane Flight Manual (AFM) to include the 
following. This may be accomplished by inserting a copy of this AD 
in the AFM.

    `` Before take-off, arm the autothrottle system (ATS).
     When cleared for take-off, activate the take-off/go-
around (TOGA) trigger(s), and positively verify ATS engagement 
[throttle movement and white steady AT1, AT2, or AT in the flight 
mode annunciator (FMA) engage window].
     If the ATS does NOT engage correctly, abort the take-
off, return, and report to maintenance.
     If the ATS does engage correctly, you may continue 
take-off with either ATS engaged or disengaged, as necessary.''

    (b) Dispatch with both thrust reversers inoperative is allowed, 
provided they are deactivated and secured in the stowed position, 
and no operations are conducted that are predicated on thrust 
reverser operation. Where there are differences between the Master 
Minimum Equipment List (MMEL) and the AD, the AD prevails.
    (c) Within 48 hours after the effective date of this AD, revise 
the FAA-approved maintenance program to include the procedures 
specified in Appendix 2 of Fokker All Operator Message TS96.67591, 
dated November 14, 1996. These procedures must be accomplished 
daily, and prior to further flight following failure of the 
operational check required by paragraph (a) of this AD. If any 
failure is detected during these procedures, prior to further 
flight, accomplish the corrective actions in accordance with the 
procedures. The FAA-approved maintenance program procedures required 
by paragraph (a)(3) of AD 96-23-16, amendment 39-9825, may be 
removed following accomplishment of the requirements of this 
paragraph.
    (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, 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.
    (f) The revision to the maintenance program shall be done in 
accordance with Fokker All Operator Message TS96.67591, dated 
November 14, 1996, including Appendix 1 and Appendix 2. 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 December 24, 1996, to 
all persons except those persons to whom it was made immediately 
effective by emergency AD 96-24-10, issued on November 19, 1996, 
which contained the requirements of this amendment.

    Issued in Renton, Washington, on December 5, 1996.
S.R. Miller,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 96-31524 Filed 12-18-96; 8:45 am]
BILLING CODE 4910-13-U