AD Amdt-39-10529

[Federal Register Volume 63, Number 95 (Monday, May 18, 1998)]
[Rules and Regulations]
[Pages 27197-27199]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 98-13062]


-----------------------------------------------------------------------

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 98-NM-153-AD; Amendment 39-10529; AD 98-11-02]
RIN 2120-AA64


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

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule; request for comments.

-----------------------------------------------------------------------

SUMMARY: This amendment adopts a new airworthiness directive (AD) that 
is applicable to all Fokker Model F28 Mark 0070 and Mark 0100 series 
airplanes. This action requires revising the Airplane Flight Manual 
(AFM) to provide the flightcrew with instructions not to arm the 
liftdumper system prior to commanding the landing gear to extend. 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 prevent inadvertent deployment of 
the liftdumpers during approach for landing, and consequent

[[Page 27198]]

reduced controllability and performance of the airplane.

DATES: Effective June 2, 1998.
    Comments for inclusion in the Rules Docket must be received on or 
before June 17, 1998.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 98-NM-153-AD, 1601 Lind Avenue, SW., 
Renton, Washington 98055-4056.
    Information pertaining to this amendment may be obtained from or 
examined at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, 
SW., Renton, Washington.

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, recently notified the 
FAA that an unsafe condition may exist on all Fokker Model F28 Mark 
0070 and Mark 0100 series airplanes. The RLD advises that an 
inadvertent in-flight liftdumper (spoiler) deployment occurred on an 
airplane that was on approach for landing. The flightcrew had no 
indication of a malfunction in the liftdumper system; however, the 
liftdumper system was armed and the engine throttle levers were set at 
or close to IDLE. When the flightcrew selected the DOWN position for 
landing gear, the liftdumpers deployed. Within approximately eleven 
seconds the liftdumpers retracted, as a result of automatic forward 
throttle movement and/or flightcrew action to switch off the liftdumper 
system.
    A preliminary investigation of the incident has indicated the cause 
to be a combination of the following:

--Electro-magnetic interference (EMI) in the outboard wheel speed 
channels caused by a faulty Flight Control Computer (FCC);
--Voltage spikes in the inboard wheelspeed channels during skid control 
box power-up on landing gear DOWN selection; and
--Liftdumper arming prior to landing gear DOWN selection.

    Fokker and the RLD are continuing to investigate the cause of the 
incident.
    Such inadvertent deployment of the liftdumpers during approach for 
landing, if not corrected, could result in reduced controllability and 
performance of the airplane.

Explanation of Relevant Service Information

    Fokker has issued All Operator Message (AOM) AOF100.044, dated 
April 8, 1998, which provides procedures to revise the Airplane Flight 
Manual (AFM) to provide the flightcrew with instructions not to arm the 
liftdumper system before commanding the landing gear to extend. The RLD 
issued Dutch airworthiness directive 1998-042 (A), dated April 10, 
1998, mandating these instructions into the AFM, in order to assure the 
continued airworthiness of these airplanes in the Netherlands.

FAA's Conclusions

    These airplane models 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 Requirements of 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 prevent inadvertent 
deployment of the liftdumpers during approach for landing, and 
consequent reduced controllability and performance of the airplane. 
This AD requires revising the Limitations and Normal Procedures 
sections of the FAA-approved AFM to provide the flightcrew with 
instructions not to arm the liftdumper system prior to commanding the 
landing gear to extend.

Differences Between This AD and the Dutch Airworthiness Directive

    This AD differs from the parallel Dutch airworthiness directive in 
that the AFM revision is reworded to include a more specific statement 
of the consequence of arming the liftdumper before commanding the 
landing gear to extend. The FAA has determined that the Limitations and 
Normal Procedures sections of the AFM must be revised to inform the 
flightcrew that arming the liftdumper before commanding the landing 
gear to extend may result in inadvertent deployment of the liftdumper.

Interim Action

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

Determination of Rule's Effective Date

    Since a situation exists that requires the immediate adoption of 
this regulation, it is found that notice and opportunity for prior 
public comment hereon are impracticable, and that good cause exists for 
making this amendment effective in less than 30 days.

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 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 98-NM-153-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

[[Page 27199]]

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, 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:

98-11-02 Fokker: Amendment 39-10529. Docket 98-NM-153-AD.

    Applicability: All Model F28 Mark 0070 and Mark 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 (b) 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 inadvertent deployment of the liftdumpers during 
approach for landing, and consequent reduced controllability and 
performance of the airplane, accomplish the following:
    (a) Within 5 days after the effective date of this AD, revise 
the Limitations and Normal Procedures sections of the FAA-approved 
Airplane Flight Manual (AFM) in accordance with paragraphs (a)(1) 
and (a)(2) of this AD. This may be accomplished by inserting a copy 
of this AD in the AFM.
    (1) Add the following information to section 5--NORMAL 
PROCEDURES, sub-Section APPROACH AND LANDING, after the subject 
APPROACH:

``BEFORE LANDING

WARNING: DO NOT ARM THE LIFTDUMPER SYSTEM BEFORE LANDING GEAR DOWN 
SELECTION.

    Selecting Landing Gear DOWN after arming the liftdumper system 
may result in inadvertent deployment of the liftdumpers, because the 
liftdumper arming test may be partially ineffective.''
    (2) Add the following information to the LIMITATIONS section:

``LIFTDUMPER SYSTEM

DO NOT ARM THE LIFTDUMPER SYSTEM BEFORE LANDING GEAR DOWN SELECTION.''

    (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, 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 2: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the International Branch, ANM-116.

    (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.

    Note 3: The subject of this AD is addressed in Dutch 
airworthiness directive 1998-042 (A), dated April 10, 1998.

    (d) This amendment becomes effective on June 2, 1998.

    Issued in Renton, Washington, on May 11, 1998.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 98-13062 Filed 5-15-98; 8:45 am]
BILLING CODE 4910-13-V