[Federal Register Volume 61, Number 29 (Monday, February 12, 1996)]
[Proposed Rules]
[Pages 5329-5331]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 96-2997]
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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39
[Docket No. 95-NM-29-AD]
Airworthiness Directives; Fokker Model F28 Mark 0100 and 0070
Series Airplanes
AGENCY: Federal Aviation Administration, DOT.
ACTION: Supplemental notice of proposed rulemaking; reopening of
comment period.
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SUMMARY: This document revises an earlier proposed airworthiness
directive (AD), applicable to certain Fokker Model F28 Mark 0100 series
airplanes, that would have required a one-time operational test of the
pitot heating system, and repair or replacement of failed elements.
That AD also would have required modification of certain electrical
wiring, and replacement of the pitot head and a certain relay. This
action revises the proposed rule by adding a new requirement to replace
the pitot heating system with a new improved system, in lieu of
modifying the electrical wiring and replacing the pitot head and relay.
This action also revises the applicability of the proposed rule to
include additional airplanes. The actions specified by this proposed AD
are intended to prevent icing of the No. 1 pitot tube, which could
result in failure of the No. 1 Air Data Computer, or output of
erroneous airspeed data to all on-side subsidiary systems, including
the Automatic Flight Control and Augmentation System.
DATES: Comments must be received by March 4, 1996.
ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), Transport Airplane Directorate, ANM-103,
Attention: Rules Docket No. 95-NM-29-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: Timothy 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-29-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-29-AD, 1601 Lind Avenue, SW., Renton, Washington
98055-4056.
Discussion
A proposal to amend part 39 of the Federal Aviation Regulations (14
CFR part 39) to add an airworthiness directive (AD), applicable to
certain Fokker Model F28 Mark 0100 series airplanes, was published as a
notice of proposed rulemaking (NPRM) in the Federal Register on April
18, 1995 (60 FR 19383). That NPRM would have required a one-time
operational test of the No. 1 pitot heating system, and repair or
replacement of failed elements. That AD also would have required
modification of certain electrical wiring, replacement of the pitot
head with a new pitot head, and replacement of the single direct
current (DC) current-sensing relay with two new DC current sensing
relays. That NPRM was prompted by reports indicating that the No. 1 Air
Data Computer (ADC #1) failed on Model F28 Mark 0100 series airplanes
due to icing at the No. 1 pitot tube. Icing of the No. 1 pitot heat
system, if not corrected, could result in failure of the ADC #1 or lead
to output of erroneous data to all on-side subsidiary systems including
the Automatic Flight Control and Augmentation System (AFCAS).
Since the issuance of that NPRM, one operator has reported that
several failures of the captain's airspeed indicator and ADC #1 have
occurred during encounters with severe icing. These failures were
accompanied by a malfunction alert from all on-side subsidiary systems;
however, no failures of the pitot heating system were reported.
Subsequent investigation revealed that the DC heating capacity of the
captain's pitot tube is inadequate to prevent freezing of the pitot
tube in severe icing conditions.
The captain's DC powered pitot heating systems installed on Fokker
Model F28 Mark 0100 series airplanes are also installed on certain
Fokker Model F28 Mark 0070 series airplanes; therefore, those airplanes
are also
[[Page 5330]]
subject to the addressed unsafe condition.
Additionally, since the issuance of that NPRM, Fokker has issued
Service Bulletin SBF100-30-017, dated August 23, 1995. This service
bulletin describes procedures for replacement of the captain's pitot
heating system with a new improved pitot heating system. This
replacement involves a new pitot tube that has an alternating current
(AC) powered heating system, that will prevent freezing of the
captain's pitot tube during severe icing conditions. (This pitot
heating system is the same system as that currently used on the First
Officer's position and auxiliary systems.) The effectivity of this
service bulletin includes certain additional Model F28 Mark 0100 series
airplanes, and certain Model F28 Mark 0070 series airplanes, that are
subject to the unsafe condition. (These airplanes were not identified
in the original NPRM.) The Rijksluchtvaartdienst (RLD), which is the
airworthiness authority for the Netherlands, approved this service
bulletin and issued Netherlands airworthiness directive BLA 1994-114/
3(A), dated September 29, 1995, in order to assure the continued
airworthiness of these airplanes in the Netherlands.
The FAA has examined the findings of the RLD and reviewed the new
service information. The FAA finds that the actions proposed in
paragraph (b) of the original NPRM will not prevent freezing of the
pitot head during severe icing conditions. Therefore, to ensure safety
of the fleet, the FAA finds that replacement of the pitot heating
system with new improved pitot heating system, as specified in Fokker
Service Bulletin SBF100-30-017, dated August 23, 1995, is necessary.
The FAA has revised paragraph (b) of this supplemental NPRM
accordingly.
In addition, the FAA has revised the applicability of this proposed
rule to include airplanes as listed in Fokker Service Bulletin SBF100-
30-017, dated August 23, 1995.
Since this change expands the scope of the originally proposed
rule, the FAA has determined that it is necessary to reopen the comment
period to provide additional opportunity for public comment.
Operators should note that the operational test of the No. 1 pitot
heating system, as proposed previously, continues to be required in
this supplemental NPRM. The FAA has determined that accomplishment of
this operational test is necessary to determine if any pitot tube
heating element is inoperative, and to ensure that any failed element
is repaired or replaced.
The FAA estimates that 129 airplanes of U.S. registry would be
affected by this proposed AD. It would take approximately 1 work hour
per airplane to accomplish the operational test and 36 work hours to
accomplish the replacement, at an average labor rate of $60 per work
hour. Required replacement parts would cost approximately $10,500 per
airplane. Based on these figures, the cost impact of the proposed AD on
U.S. operators is estimated to be $1,640,880, or $12,720 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.
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), 40113, 44701.
Sec. 39.13 [Amended]
2. Section 39.13 is amended by adding the following new
airworthiness directive:
Fokker: Docket 95-NM-29-AD.
Applicability: Model F28 Mark 0100 and 0070 series airplanes; as
listed in Fokker SBF100-30-015, Revision 2, dated January 25, 1995,
and Fokker Service SBF100-30-017, dated August 23, 1995;
certificated in any category.
Note 1: This AD applies to each airplane identified in the
preceding applicability provision, regardless of whether it has been
otherwise 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 prevent icing of the No. 1 pitot tube, which could
result in failure of the No. 1 Air Data Computer (ADC #1) or output
of erroneous airspeed data to all on-side subsidiary systems,
including the Automatic Flight Control and Augmentation System
(AFCAS), accomplish the following:
(a) For airplanes listed in Fokker SBF100-30-015, Revision 2,
dated January 25, 1995: Within 30 days after the effective date of
this AD, perform an operational test of the No. 1 pitot heating
system in accordance with Part 1 of the Accomplishment Instructions
of that service bulletin.
(1) If the pitot heating system passes the operational test,
accomplish the requirements of either paragraph (b)(1) or (b)(2) of
this AD, as applicable, at the times specified.
(2) If any pitot tube heating element is found to be
inoperative, prior to further flight, repair or replace the failed
element with a serviceable element, in accordance with the Fokker
100 Aircraft Maintenance Manual (AMM).
(b) For all airplanes: Replace the No. 1 pitot heating system
with a new pitot heating system, in accordance with Part 1, 2, 3, or
4 of the Accomplishment Instructions of Fokker Service Bulletin
SBF100-30-017, dated August 23, 1995. Accomplish this action at the
time specified in paragraph (b)(1) or (b)(2) of this AD, as
applicable.
(1) For airplanes that are equipped with a Flight Warning System
(FWS) speed comparator that is not activated, and a Rosemount type
853JB No. 1 pitot heating system: Accomplish the replacement within
9 months after the effective date of this AD.
(2) For airplanes that are equipped either with an FWS speed
comparator that is activated, or with a Rosemount type 853KK No. 1
pitot heating system: Accomplish the replacement within 18 months
after the effective date of this AD.
[[Page 5331]]
(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, 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.
(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.
Issued in Renton, Washington, on February 6, 1996.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 96-2997 Filed 2-9-96; 8:45 am]
BILLING CODE 4910-13-U
