[Federal Register Volume 63, Number 25 (Friday, February 6, 1998)]
[Rules and Regulations]
[Pages 6066-6069]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-2825]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 96-NM-269-AD; Amendment 39-10310; AD 98-03-18]
RIN 2120-AA64
Airworthiness Directives; Fokker Model F28 Mark 0100 and 0070
Series Airplanes
AGENCY: Federal Aviation Administration, DOT.
ACTION: Final rule.
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SUMMARY: This amendment supersedes an existing airworthiness directive
(AD), applicable to all Fokker Model F28 Mark 0100 and 0070 series
airplanes, that currently requires revising the Airplane Flight Manual
(AFM) to include information that will enable the flightcrew to
identify failures of the emergency direct current (DC)/alternating
current (AC) bus power supply and to take appropriate corrective
actions. This amendment requires a new terminating modification for the
existing AFM revisions. This amendment also requires a new AFM revision
to inform the flightcrew that, under certain conditions, an ``EMER DC
BUS'' warning on the multi-function display unit (MFDU) will occur, and
to take appropriate corrective actions. This amendment is prompted by
the issuance of mandatory continuing airworthiness information by a
foreign civil airworthiness authority. The actions specified by this AD
are intended to prevent failures of the emergency DC/AC bus power
supply, which could reduce the ability of the flightcrew to control the
airplane.
DATES: Effective March 23, 1998.
The incorporation by reference of certain publications listed in
the regulations is approved by the Director of the Federal Register as
of March 23, 1998.
ADDRESSES: The service information referenced in this AD may be
obtained from Fokker Services B.V., Technical Support Department, P. O.
Box 75047, 1117 ZN Schiphol Airport, the Netherlands. 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: 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: A proposal to amend part 39 of the Federal
Aviation Regulations (14 CFR part 39) by superseding AD 95-21-10,
amendment 39-9396 (60 FR 53110, October 12, 1995), which is applicable
to all Fokker Model F28 Mark 0100 and 0070 series airplanes, was
published in the Federal Register on January 16, 1997 (62 FR 2324). The
action proposed to supersede AD 95-21-10 to continue to require
revising the Abnormal and Normal Procedures Sections of the FAA-
approved Airplane Flight Manual (AFM) to include information that will
enable the flightcrew to identify failures of the emergency direct
current (DC)/alternating current (AC) bus power supply and to take
appropriate corrective actions. The action also proposed to require a
modification of the DC bus transfer system, which would terminate the
existing requirements for the AFM revisions. In addition, the action
proposed to require revising the Abnormal Procedures Section of the AFM
to inform the flightcrew that an ``EMER DC BUS'' warning on the multi-
function display unit (MFDC) will occur when the emergency DC bus is
transferred to battery power, and to take appropriate corrective
actions.
Interested persons have been afforded an opportunity to participate
in the making of this amendment. Due consideration has been given to
the comments received.
Request to Revise Cost Impact Information
One commenter supports the proposed rule, but estimates that the
modification required by this AD will cost $4,250 per airplane, which
is more than the $3,380 per airplane estimate in the proposed rule.
The FAA infers that the commenter requests that the cost impact
information for this AD be revised. The FAA agrees that cost impact of
the required modification is more than the estimated $3,380 per
airplane contained in the proposed rule. Since issuance of the Notice
of Proposed Rulemaking (NPRM), Fokker has issued Service Bulletin
SBF100-24-032, Revision 1, dated April 25, 1997, and Revision 2, dated
July 28, 1997, to correct minor errors, and to revise the work hour
estimates and part cost estimates for accomplishment of the
modification. The estimate for accomplishment of Part 1 of the
Accomplishment Instructions of the service bulletin has been changed
[[Page 6067]]
from 17 work hours to 22 work hours, and the estimate for
accomplishment of Part 2 of the Accomplishment Instructions of the
service bulletin has been changed from 5 work hours to 13 work hours.
In addition, the estimate for parts costs has been changed from a range
of $160 to $2,360, to a range of $160 to $2,580. The FAA has revised
the cost impact information, below, accordingly.
The FAA has determined that accomplishment of the modification in
accordance with the original issue, Revision 1, or Revision 2 of Fokker
Service Bulletin SBF100-24-032 adequately addresses the identified
unsafe condition. Therefore, this AD has been revised to include Fokker
Service Bulletin SBF100-24-032, Revision 1, dated April 25, 1997, and
Revision 2, dated July 28, 1997, as additional sources of service
information.
Request To Extend Compliance Time for Modification
The Air Transport Association (ATA) of America, on behalf of one of
its members, requests that the compliance time for accomplishing the
modification be extended from the proposed 12 months to 18 months. The
commenter states that if it is forced to meet the proposed 12-month
compliance schedule, approximately 20 of the 40 affected airplanes in
its fleet would require modification in a line environment or during
unscheduled heavy maintenance visits. The commenter noted that this
would result in significant additional costs. In addition, the
commenter states that the modification would be difficult to accomplish
during routine overnight line station maintenance due to the complexity
of the task and accessibility. The commenter also noted that the
elapsed time to accomplish the modification will be twice the service
bulletin estimate of 8 hours, since only one person at a time could
work on this modification. The commenter further noted that only three
diode failures have been experienced on its affected fleet of airplanes
since operation commenced in 1989. The commenter considers that this
relatively low failure rate also supports its request for an extension
of the compliance time.
The FAA does not concur with the commenter's request to extend the
compliance time. In developing an appropriate compliance time for this
action, the FAA considered not only the degree of urgency associated
with addressing the subject unsafe condition, but the manufacturer's
and foreign airworthiness authority's recommendations as to an
appropriate compliance time, the availability of required parts, and
the practical aspect of installing the required modification within an
interval of time that parallels the normal scheduled maintenance for
the majority of affected operators. The FAA has determined that the
compliance time, as proposed, represents the maximum interval of time
allowable for the affected airplanes to continue to operate prior to
accomplishing the required modification without compromising safety.
The commenter has not provided data to substantiate why an extension of
the compliance time would not compromise safety. The failure rate data
of a single operator does not substantiate why an extension of the
compliance time would not compromise safety.
In consideration of all of these factors, and in consideration of
the amount of time that has already elapsed since issuance of the
original NPRM, the FAA has determined that further delay of this
modification is not appropriate. However, under the provisions of
paragraph (g) of the final rule, the FAA may approve requests for
adjustments to the compliance time if data are submitted to
substantiate that such an adjustment would provide an acceptable level
of safety.
Conclusion
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
significantly increase the economic burden on any operator nor increase
the scope of the AD.
Cost Impact
There are approximately 132 Fokker Model F28 Mark 0100 and 0070
series airplanes of U.S. registry that will be affected by this AD.
The actions that are currently required by AD 95-21-10 take
approximately 1 work hour per airplane to accomplish, at an average
labor rate of $60 per work hour. Based on these figures, the cost
impact of the previously required actions on U.S. operators is
estimated to be $7,920, or $60 per airplane.
The modification of the DC bus transfer system that is required by
this new AD will take approximately 22 (Part 1 of the Accomplishment
Instructions of the service bulletin) or 13 (Part 2 of the
Accomplishment Instructions of the service bulletin) work hours per
airplane to accomplish, at an average labor rate of $60 per work hour.
The cost of required parts will range from $160 to as much as $2,580
per airplane. Based on these figures, the cost impact of the
modification required by this AD on U.S. operators is estimated to be
between $940 and $3,900 per airplane.
The AFM revision that is required by this new AD would take
approximately 1 work hour per airplane to accomplish, at an average
labor rate of $60 per work hour. Based on these figures, the cost
impact of the AFM revision required by this AD on U.S. operators is
estimated to be $7,920, or $60 per airplane.
The cost impact figures discussed above are 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.
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.
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:
[[Page 6068]]
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 removing amendment 39-9396 (60 FR
53110, October 12, 1995), and by adding a new airworthiness directive
(AD), amendment 39-10310, to read as follows:
98-03-18 Fokker: Docket 96-NM-269-AD. Supersedes AD 95-21-10,
Amendment 39-9396.
Applicability: All Model F28 Mark 0100 and 0070 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 (g) 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 failures of the emergency direct current (DC)/
alternating current (AC) bus power supply, which could reduce the
ability of the flightcrew to control the airplane, accomplish the
following:
Restatement of Actions Required by AD 95-21-10, Amendment 39-9396
Note 2: For Model F28 Mark 0070 series airplanes, on which the
procedures specified in Fokker Service Bulletins SBF100-24-033 and
SBF100-24-034 have been accomplished, the AFM revisions required by
paragraphs (a), (b), and (c) of this AD may be removed from the AFM.
Note 3: For Model F28 Mark 0100 series airplanes, on which the
procedures specified in Fokker Service Bulletin SBF100-24-030 have
not been accomplished, or on which the procedures specified in
Fokker Service Bulletin SBF100-24-033 have been accomplished; the
AFM revisions required by paragraphs (a), (b), and (c) of this AD
may be removed from the AFM.
(a) For all airplanes: Within 7 days after October 27, 1995 (the
effective date of AD 95-21-10, amendment 39-9396), revise the
Abnormal Procedures Section of the FAA-approved Airplane Flight
Manual (AFM) to include the following statement. This may be
accomplished by inserting a copy of this AD in the AFM.
``Section 4--Abnormal Procedures
Add to Sub-section 4.04--Electrical Power
STANDBY ANNUNCIATOR PANEL RED AC SUPPLY LIGHT ``ON''
On overhead electrical panel:
GEN LOAD..........................................................CHECK
If all generator loads are approximately zero:
LOSS OF AC SUPPLY PROCEDURE.......................................APPLY
If not all generator loads are approximately zero:
DC EMER BUS SUPPLY TRU3 CIRCUIT BREAKER...........................CHECK
If circuit breaker has tripped:
DC EMER BUS SUPPLY TRU3 CIRCUIT BREAKER...........................RESET
--If reset is unsuccessful:
L and R AUDIO......................................................ALTN
Anticipate the effects of an eventual EMER DC BUS failure, see
EMER DC BUS FAULT procedure.
If circuit breaker has not tripped:
L and R AUDIO......................................................ALTN
Anticipate the effects of an eventual EMER DC BUS failure, see
EMER DC BUS FAULT procedure.''
(b) For all airplanes: Within 7 days after October 27, 1995,
revise the Normal Procedures Section of the FAA-approved AFM to
include the following statement. This may be accomplished by
inserting a copy of this AD in the AFM.
``Section 5--Normal Procedures
Insert in front of Sub-section 5.01.01--Take-off
After engine start, select the Standby Annunciator
Panel (SAP) backup mode ON via the BACKUP p/b at the SAP.
Keep the SAP in the backup mode for the whole duration
of flight until engine shutdown.
Monitor the SAP.
Note: Failure conditions as presented on the SAP bypass the
Flight Warning Computer (FWC) are not subject to alert inhibition.
Be aware that the red LG light on the SAP will illuminate in case
one or both thrustlever(s) are below the minimum take-off position
and the landing gear is not down.''
(c) For all Model F28 Mark 0070 series airplanes; and Model F28
Mark 0100 series airplanes, in pre-SBF100-24-009 configuration or in
post SBF100-24-030 configuration: Within 7 days after October 27,
1995, revise the Abnormal Procedures Section of the FAA-approved AFM
to include the following statement. This may be accomplished by
inserting a copy of this AD in the AFM.
``Section 4--Abnormal Procedures
Add to Sub-section 4.04--Electrical Power
ERRATIC ELECTRICAL SYSTEM BEHAVIOR
In case of continuous rattling sound, caused by the fast
switching of relays and accompanied by blanking or erratic behavior
of the three displays on the electric panel:
BATTERIES...............................SELECT MOMENTARILY OFF, THEN ON
AFFECTED SYSTEMS........................................RESTORE IF REQD
If the red AC SUPPLY light on the SAP comes ON:
SAP RED AC SUPPLY LIGHT `ON' PROCEDURE..........................APPLY''
New Actions Required by This AD
(d) For Model F28 Mark 0070 and 0100 series airplanes, as listed
in Fokker Service Bulletin SBF100-24-032, dated September 12, 1996,
or Revision 1, dated April 25, 1997, or Revision 2, dated July 28,
1997: Within 12 months after the effective date of this AD, modify
the DC bus transfer system in accordance with Fokker Service
Bulletin SBF100-24-032, dated September 12, 1996; or Revision 1,
dated April 25, 1997; or Revision 2, dated July 28, 1997. Prior to
further flight following accomplishment of this modification,
accomplish paragraph (e) of this AD.
Note 4: For Fokker Model F28 Mark 0070 series airplanes, Fokker
Service Bulletin SBF100-24-032 recommends prior or concurrent
accomplishment of the procedures specified in Fokker Service
Bulletin SBF100-24-034, dated October 17, 1995, or Revision 1, dated
September 12, 1996 (which is currently required by AD 96-26-03,
amendment 39-9866).
(e) Revise the Abnormal Procedures Section of the FAA-approved
AFM to include the following statement. This may be accomplished by
inserting a copy of this AD in the AFM.
``Section 4--Abnormal Procedures
Sub-section 4.04.05--Electrical Power--Bus Equipment List
Insert a marker {time} in each Bus Equipment List table, at the
top of the column marked: EMERGENCY--DC.
Add the following note at the beginning of the affected sub-
section:
Note: {time} When an ``EMER DC BUS'' fault is presented on the
multi-function display unit (MFDU), check whether the electric panel
digital readouts are operative.
If operative, the EMER DC bus is supplied from the
battery chargers via the batteries for 90 minutes and all services
connected to this bus will remain available. After this time period,
batteries will start to discharge and the effects of an EMER DC BUS
fault should then be expected.
If inoperative, continue with the EMER DC BUS FAULT
procedure.
At the bottom of each succeeding page (Bus Equipment List table)
of sub-section 4.04.05, make a clear reference to the note marked
{time} located at the beginning of sub-section 4.04.05.''
(f) Accomplishment of the modification in accordance with
paragraph (d) of this AD constitutes terminating action for the
requirements of paragraphs (a), (b), and (c) of this AD. After the
modification has been accomplished, the previously required AFM
revision may be removed from the AFM.
(g) 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,
[[Page 6069]]
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 5: Information concerning the existence of approved
alternative methods of compliance with this AD, if any, may be
obtained from the International Branch, ANM-116.
(h) 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.
(i) The actions shall be done in accordance with the following
Fokker service bulletins, which contain the specified effective
pages:
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Service bulletin referenced and Revision level shown
date Page No. on page Date shown on page
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SBF100-24-032, September 12, 1996. 1-46................ Original............. September 12, 1996.
SBF100-24-032, Revision 1, April 1-4, 7-62........... 1.................... April 25, 1997.
25, 1997.
5-6................. Original............. September 12, 1996.
SBF100-24-032, Revision 2, July 1-2, 13, 15, 29-30.. 2.................... July 28, 1997.
28, 1997.
3-4, 7-12, 14, 16- 1.................... April 25, 1997.
28, 31-62.
5-6................. Original............. September 12, 1996.
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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 Services B.V., Technical
Support Department, P.O. Box 75047, 1117 ZN Schiphol Airport, the
Netherlands. 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.
Note 6: The subject of this AD is addressed in Dutch
airworthiness directive BLA 1995-089/4, dated September 30, 1996.
(j) This amendment becomes effective on March 23, 1998.
Issued in Renton, Washington, on January 30, 1998.
Stewart R. Miller,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 98-2825 Filed 2-5-98; 8:45 am]
BILLING CODE 4910-13-P
