[Federal Register Volume 67, Number 66 (Friday, April 5, 2002)]
[Proposed Rules]
[Pages 16333-16335]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 02-8284]


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

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2001-NM-290-AD]
RIN 2120-AA64


Airworthiness Directives; Fokker Model F.28 Mark 0070 and 0100 
Series Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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

SUMMARY: This document proposes the adoption of a new airworthiness 
directive (AD) that is applicable to all Fokker Model F.28 Mark 0070 
and 0100 series airplanes. This proposal would require measurement of 
the over-center force of the thrust reverser operating levers; a 
functional test to verify proper energizing of the secondary lock 
solenoid of the thrust reversers; and corrective actions, if necessary. 
This action is necessary to detect and correct an insufficient over-
center force in the corresponding thrust reverser operating lever, and 
incorrect setting of the thrust reverser selector switch (S9), which 
could result in uncommanded deployment of the thrust reversers during 
flight and consequent reduced controllability of the airplane. This 
action is intended to address the identified unsafe condition.

DATES: Comments must be received by May 6, 2002.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 2001-NM-290-AD, 1601 Lind Avenue, SW., 
Renton, Washington 98055-4056. Comments may be inspected at this 
location between 9 a.m. and 3 p.m., Monday through Friday, except 
Federal holidays. Comments may be submitted via fax to (425) 227-1232. 
Comments may also be sent via the Internet using the following address: 
[email protected]. Comments sent via fax or the Internet must 
contain ``Docket No. 2001-NM-290-AD'' in the subject line and need not 
be submitted in triplicate. Comments sent via the Internet as attached 
electronic files must be formatted in Microsoft Word 97 for Windows or 
ASCII text.
    The service information referenced in the proposed rule may be 
obtained from Fokker Services B.V., P.O. Box 231, 2150 AE Nieuw-Vennep, 
the Netherlands. This information may be examined at the FAA, Transport 
Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington.

FOR FURTHER INFORMATION CONTACT: Tom Rodriguez, Aerospace Engineer, 
International Branch, ANM-116, FAA, Transport Airplane Directorate, 
1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (425) 
227-1137; fax (425) 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 action may be changed in 
light of the comments received.
    Submit comments using the following format:
     Organize comments issue-by-issue. For example, discuss a 
request to change the compliance time and a request to change the 
service bulletin reference as two separate issues.
     For each issue, state what specific change to the proposed 
AD is being requested.
     Include justification (e.g., reasons or data) for each 
request.
    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

[[Page 16334]]

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 action must submit a self-addressed, 
stamped postcard on which the following statement is made: ``Comments 
to Docket Number 2001-NM-290-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-114, Attention: Rules 
Docket No. 2001-NM-290-AD, 1601 Lind Avenue, SW., Renton, Washington 
98055-4056.

Discussion

    The Civil Aviation Authority--The Netherlands (CAA-NL), which is 
the airworthiness authority for the Netherlands, notified the FAA that 
an unsafe condition may exist on all Fokker Model F.28 Mark 0070 and 
0100 series airplanes. The CAA-NL advises that an in-flight thrust 
reverser deployment occurred at the top of descent. The flightcrew 
encountered some buffeting, but no controllability problems. Forty-five 
seconds later, at a lower airspeed, the hydraulic pressure on the stow 
port of the thrust reverser actuator overpowered the aerodynamic forces 
on the deployed thrust reverser doors and closed them. Subsequent 
investigation revealed that the thrust reverser selector switch (S9), 
located in the left-hand thrust lever switchbox, was very critically 
adjusted. Additionally, the incident airplane had insufficient over-
center force on the left-hand thrust reverser operating lever, and the 
corresponding ``ground/flight'' switch had remained unnoticed by the 
flightcrew in the ``ground'' position. Consequently, the addition of 
firm manual retardation of the thrust levers to IDLE resulted in a 
temporary, unintentional operation of the thrust reverser selector 
switch (S9).
    Incorrect setting of the thrust reverser selector switch (S9) and 
an insufficient over-center force in the corresponding thrust reverser 
operating lever, if not corrected, could result in uncommanded 
deployment of one or both thrust reversers during flight and consequent 
reduced controllability of the airplane.

Explanation of Relevant Service Information

    Fokker Services B.V. has issued Service Bulletin SBF100-76-015, 
dated January 15, 2001, including Manual Change Notification MCNM F100-
060, dated January 1, 2001, which describes procedures for measurement 
of the over-center force of the left- and right-hand thrust reverser 
operating levers, and corrective actions, if necessary. The corrective 
actions include measuring and readjusting the minimum stop of the 
reverse-thrust lever and over-center force of the thrust reverser. The 
service bulletin also describes procedures for a functional test to 
verify proper energizing of the secondary lock solenoid of the left- 
and right-hand thrust reversers, and corrective actions, if necessary. 
The corrective actions include a rigging test of the thrust reverser 
switchbox, another functional test to verify proper energizing of the 
secondary lock solenoid, and replacement of the thrust reverser 
switchbox with a new or serviceable switchbox, if necessary. The CAA-NL 
classified this service bulletin as mandatory and issued Dutch 
airworthiness directive 2001-040, dated March 30, 2001, 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 CAA-NL has kept the FAA 
informed of the situation described above. The FAA has examined the 
findings of the CAA-NL, 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 Proposed 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, the proposed AD would require accomplishment of 
the actions specified in the service bulletin described previously, 
except as discussed below.

Difference Between Proposed Rule and Service Bulletin

    In lieu of performing corrective actions, the service bulletin 
allows a readjustment of the over-center force of the thrust reverser 
operating lever to be scheduled for the next scheduled hangar check or 
within 1,000 flight hours, whichever comes first. The FAA has 
determined that such rescheduling would not address the identified 
unsafe condition in a timely manner. In developing an appropriate 
compliance time for this AD, the FAA considered not only the 
manufacturer's recommendation, but the degree of urgency associated 
with addressing the subject unsafe condition, the average utilization 
of the affected fleet, and the time necessary to perform the proposed 
corrective actions. In light of all of these factors, the FAA finds 
that the proposed corrective actions should be accomplished before 
further flight.

Interim Action

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

Cost Impact

    The FAA estimates that 139 airplanes of U.S. registry would be 
affected by this proposed AD, that it would take approximately 2 work 
hours per airplane to accomplish the proposed actions, and that the 
average labor rate is $60 per work hour. Based on these figures, the 
cost impact of the proposed AD on U.S. operators is estimated to be 
$16,680, or $120 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 proposed AD were not adopted. The cost impact 
figures discussed in AD rulemaking actions represent only the time 
necessary to perform the specific actions actually required by the AD. 
These figures typically do not include incidental costs, such as the 
time required to gain access and close up, planning time, or time 
necessitated by other administrative actions.

Regulatory Impact

    The regulations proposed herein would not have a substantial direct 
effect 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, it 
is determined that this proposal would not have federalism implications 
under Executive Order 13132.
    For the reasons discussed above, I certify that this proposed 
regulation (1) is not a ``significant regulatory action''

[[Page 16335]]

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 U.S.C. 106(g), 40113, 44701.


Sec. 39.13  [Amended]

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

Fokker Services B.V.: Docket 2001-NM-290-AD.

    Applicability: All Model F.28 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 (c) 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 detect and correct incorrect an insufficient over-center 
force in the corresponding thrust reverser operating lever and 
incorrect setting of the thrust reverser selector switch (S9), which 
could result in uncommanded deployment of the thrust reversers 
during flight and consequent reduced controllability of the 
airplane, accomplish the following:

Over-Center Force Measurement and Readjustment

    (a) Within 6 months after the effective date of this AD, measure 
the over-center force of the left- and right-hand thrust reverser 
operating levers, per paragraph 2.A. of the Accomplishment 
Instructions of Fokker Service Bulletin SBF100-76-015, dated January 
15, 2001, including Manual Change Notification MCNM F100-060, dated 
January 1, 2001.
    (1) If the over-center force is equal to or higher than 4.5 
pounds, but not higher than 5.5 pounds, no further action is 
required by this paragraph.
    (2) If the over-center force is less than 4.5 pounds or higher 
than 5.5 pounds, before further flight, readjust the over-center 
force and accomplish the corrective actions (including measuring and 
readjusting the minimum stop of the reverse-thrust lever and over-
center force of the thrust reverser), per the service bulletin.

Functional Test and Corrective Actions

    (b) Within 6 months after the effective date of this AD, perform 
a functional test to verify proper energizing of the secondary lock 
solenoid of the left- and right-hand thrust reversers, per paragraph 
2.B. of the Accomplishment Instructions of Fokker Service Bulletin 
SBF100-76-015, dated January 15, 2001, including Manual Change 
Notification MCNM F100-060, dated January 1, 2001.
    (1) If the secondary lock solenoid does NOT (momentarily or 
continuously) energize with movement of the thrust reverser 
operating lever as described in paragraph 2.B.(9) of the service 
bulletin, no further action is required by this paragraph.
    (2) If the secondary lock solenoid (momentarily or continuously) 
energizes with movement of the thrust reverser operating lever as 
described in paragraph 2.B.(9) of the service bulletin, before 
further flight, perform a rigging test of the thrust reverser 
switchbox and repeat the functional test to verify proper energizing 
of the secondary lock solenoid one more time, per paragraph 2.B.(9) 
of the service bulletin.
    (i) If the solenoid does NOT (momentarily or continuously) 
energize with movement of the thrust reverser operating lever as 
described in paragraph 2.B.(9) of the service bulletin, no further 
action is required by this paragraph.
    (ii) If the secondary lock solenoid still (momentarily or 
continuously) energizes with movement of the thrust reverser 
operating lever as described in paragraph 2.B.(9) of the service 
bulletin, before further flight, replace the thrust reverser 
switchbox with a new or serviceable switchbox, per the service 
bulletin.

Alternative Methods of Compliance

    (c) 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, 
Transport Airplane Directorate, FAA. 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.

Special Flight Permits

    (d) 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 2001-040, dated March 30, 2001.


    Issued in Renton, Washington, on March 28, 2002.
Kalene C. Yanamura,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 02-8284 Filed 4-4-02; 8:45 am]
BILLING CODE 4910-13-P