[Federal Register Volume 71, Number 122 (Monday, June 26, 2006)]
[Proposed Rules]
[Pages 36252-36255]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: E6-10014]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2003-NM-114-AD]
RIN 2120-AA64


Airworthiness Directives; Saab Model SAAB-Fairchild SF340A (SAAB/
SF340A) and SAAB 340B 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 Saab Model SAAB-Fairchild SF340A 
(SAAB/SF340A) and SAAB 340B airplanes, that would have required 
modification of the hot detection system of the tail pipe harness of 
the engine nacelles. This new action revises the original NPRM by 
reducing the compliance time for the modification and adding repetitive 
inspections. The actions specified by this new proposed AD are intended 
to prevent false warning indications to the flightcrew from the hot 
detection system due to discrepancies of the harness, which could 
result in unnecessary aborted takeoffs on the ground or an in-flight 
engine shutdown. This action is intended to address the identified 
unsafe condition.

DATES: Comments must be received by July 21, 2006.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 2003-NM-114-AD, 1601 Lind Avenue, SW., 
Renton, Washington 98055-4056.

[[Page 36253]]

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. 2003-
NM-114-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 or 2000 or ASCII text.
    The service information referenced in the proposed rule may be 
obtained from Saab Aircraft AB, SAAB Aircraft Product Support, S-
581.88, Linkping, Sweden. This information may be examined at the FAA, 
Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, 
Washington.

FOR FURTHER INFORMATION CONTACT: Mike Borfitz, Aerospace Engineer, 
International Branch, ANM-116, Transport Airplane Directorate, FAA, 
1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (425) 
227-2677; 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 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 2003-NM-114-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. 2003-NM-114-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 Saab Model SAAB SF340A and SAAB 340B series airplanes, was 
published as a notice of proposed rulemaking (NPRM) in the Federal 
Register on April 1, 2004 (69 FR 17101). That NPRM would have required 
modification of the hot detection system of the tail pipe harness of 
the engine nacelles. That NPRM was prompted by reports of false warning 
indications to the flightcrew from the hot detection system of the tail 
pipe harness of the engine nacelles. That condition, if not corrected, 
could result in unnecessary aborted takeoffs on the ground or an in-
flight engine shutdown.

Actions Since Issuance of Original NPRM

    Since the issuance of the original NPRM, we have been receiving 
reports from operators indicating new incidents of false warning 
indications to the flightcrew from the hot detection system of the tail 
pipe harness of the engine nacelles. We have determined that, the 
unsafe condition is severe enough to justify adding repetitive general 
visual inspections after accomplishing the modification, in order to 
maintain an appropriate level of safety. The one-time inspection 
specified in the original NPRM was determined to be appropriate in 
consideration of the safety implications at that time. However, in 
light of the additional reports, we have added repetitive inspections 
at intervals not to exceed 12 months to paragraph (a) of this 
supplemental NPRM.
    This supplemental NPRM also requires that operators report the 
results of all hot tail pipe events to the Swedish Civil Aviation 
Authority (Luftfartsstyrelsen). Because the cause of the events is not 
known, these required reports will help determine the extent of the 
problem in the affected fleet. Based on the results of these reports, 
we may determine that further corrective action is warranted.

New Relevant Service Information

    We have received Saab Service Bulletin 340-26-030, Revision 01, 
dated November 14, 2003. (The original NPRM refers to Service Bulletin 
340-26-030, dated October 28, 2002, as the appropriate source of 
service information for accomplishing the proposed actions.) Revision 
01 of the service bulletin adds no significant changes to the original 
issue and has been added to the supplemental NPRM as the appropriate 
source of service information for accomplishing the actions.

Comments

    Due consideration has been given to the comments received in 
response to the original NPRM.

Request To Add Certain Repetitive Inspection Requirements

    Mesaba Airlines states that initially it had problems with false 
warning indications from the hot detection system, and after several 
attempts, came up with a process to seal the tail pipe hot detectors 
with thixotropic sealant. The commenter notes that the work 
instructions it developed were added to Saab Service Bulletin 340-26-
029, and adds that it has had success with this new process and has had 
a low number of false warning indications. The commenter states that 
the inspection and application of sealant specified in its Maintenance 
Review Board (MRB) Item 26-12-01 (Bench Check of Exhaust Duct Overtemp 
Spot Detectors) are done every 6,000 flight hours; the replacement of 
the spot detectors is done at the same time. (The inspection is 
referenced as Task 0600-454-01E and Task 0600-464-
01E, and the application of sealant is referenced as Chapter 26-12-05, 
in the SAAB 340 Airplane Maintenance Manual.) The commenter asks that 
this visual inspection of the harness and associated terminal ends, and 
application of thixotropic sealant to the detector/terminal end areas 
every 6,000 flight hours be added to the original NPRM. The commenter 
adds that these actions would be done in conjunction with the 
replacement of the spot detectors.
    We partially agree with the commenter. We agree that additional 
general visual inspections, as identified

[[Page 36254]]

by the commenter, are necessary. We do not agree that those inspections 
can be done at intervals of 6,000 flight hours, as specified in the 
referenced maintenance manual. In light of the additional incidents 
that have occurred, a repetitive interval of 6,000 flight hours would 
not address the unsafe condition in a timely manner. We have revised 
paragraph (a) of this supplemental NPRM to specify accomplishing a 
general visual inspection for discrepancies of the heat shrink sleeve, 
thixotropic sealant, and connectors for damage and/or corrosion, and 
doing all applicable repairs. We find that repetitive inspections and 
maintenance done every 12 months will result in a decrease in incidents 
of false warning indications to the flightcrew from the hot detection 
system. Additionally, we do not agree to add replacement of the spot 
detectors in conjunction with the actions because such replacement is 
an on-condition action.

Request To Add Parts Cost

    Saab Aircraft states that in the ``Cost Impact'' section of the 
original NPRM we have specified that required parts would be free of 
charge. The commenter notes that Paragraph 1.G. (Material--Cost and 
Availability) of the referenced service bulletin specifies, ``Price and 
availability for Modification Kit No. SAAB 340-26--3-01/02 will be 
furnished on request.'' The commenter provided the parts cost for the 
kits and asked that the cost be added to the original NPRM. We agree, 
and we have changed the cost impact section of this supplemental NPRM 
to reflect the parts cost.

Explanation of Change to Applicability

    We have revised the applicability of the original NPRM to identify 
model designations as published in the most recent type certificate 
data sheet for the affected models.

Explanation of Change to Costs of Compliance

    After the original NPRM was issued, we reviewed the figures we have 
used over the past several years to calculate AD costs to operators. To 
account for various inflationary costs in the airline industry, we find 
it necessary to increase the labor rate used in these calculations from 
$65 per work hour to $80 per work hour. The cost impact information, 
below, reflects this increase in the specified hourly labor rate.

Conclusion

    Since certain changes expand the scope of the original NPRM, we 
have determined that it is necessary to reopen the comment period to 
provide additional opportunity for public comment.

Cost Impact

    We estimate that 280 airplanes of U.S. registry would be affected 
by this supplemental NPRM.
    It would take about 10 work hours per airplane to accomplish the 
proposed modification, at an average labor rate of $80 per work hour. 
Required parts cost would be between $218 and $2,253. Based on these 
figures, the cost impact of the proposed modification on U.S. operators 
is estimated to be between $1,018 and $3,053 per airplane.
    It would take about 1 work hour per airplane to accomplish the 
proposed inspection and application of sealant, at an average labor 
rate of $80 per work hour. Based on these figures, the cost impact of 
this proposed action on U.S. operators is estimated to be $22,400, or 
$80 per airplane, per inspection cycle.
    The cost impact figures discussed above are 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 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.

Authority for This Rulemaking

    Title 49 of the United States Code specifies the FAA's authority to 
issue rules on aviation safety. Subtitle I, section 106, describes the 
authority of the FAA Administrator. Subtitle VII, Aviation Programs, 
describes in more detail the scope of the Agency's authority.
    We are issuing this rulemaking under the authority described in 
subtitle VII, part A, subpart III, section 44701, ``General 
requirements.'' Under that section, Congress charges the FAA with 
promoting safe flight of civil aircraft in air commerce by prescribing 
regulations for practices, methods, and procedures the Administrator 
finds necessary for safety in air commerce. This regulation is within 
the scope of that authority because it addresses an unsafe condition 
that is likely to exist or develop on products identified in this 
rulemaking action.

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'' 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:
Saab Aircraft AB: Docket 2003-NM-114-AD.

Applicability

    Model SAAB-Fairchild SF340A (SAAB/SF340A) airplanes, serial 
numbers -004 through -159 inclusive, and SAAB 340B airplanes, serial 
numbers -160 through -459 inclusive, certificated in any category.

Compliance

    Required as indicated, unless accomplished previously.
    To prevent false warning indications to the flightcrew from the 
hot detection system of the tail pipe harness of the engine nacelles 
due to discrepancies of the harness, which could result in 
unnecessary aborted takeoffs

[[Page 36255]]

on the ground or an in-flight engine shutdown, accomplish the 
following:

Modification/Repetitive Inspections

    (a) Within 12 months after the effective date of this AD: Modify 
the hot detection system of the tail pipe harness of the engine 
nacelles (including a general visual inspection of the heat shrink 
sleeve, thixotropic sealant, and connectors for damage and/or 
corrosion, and all applicable repairs), by doing all the actions 
specified in the Accomplishment Instructions of Saab Service 
Bulletin 340-26-030, Revision 01, dated November 14, 2003. All 
applicable repairs must be done before further flight in accordance 
with the service bulletin. Repeat the general visual inspection 
thereafter at intervals not to exceed 12 months.


    Note 1: For the purposes of this AD, a general visual inspection 
is defined as: ``A visual examination of an interior or exterior 
area, installation, or assembly to detect obvious damage, failure, 
or irregularity. This level of inspection is made from within 
touching distance unless otherwise specified. A mirror may be 
necessary to enhance visual access to all exposed surfaces in the 
inspection area. This level of inspection is made under normally 
available lighting conditions such as daylight, hangar lighting, 
flashlight, or droplight and may require removal or opening of 
access panels or doors. Stands, ladders, or platforms may be 
required to gain proximity to the area being checked.''


    (b) Accomplishing the modification/repetitive inspections 
specified in Saab Service Bulletin 340-26-030, dated October 28, 
2002; or Saab Service Bulletins 340-26-018, Revision 02, and 340-26-
029, both dated October 28, 2002; before the effective date of this 
AD, is considered acceptable for compliance with the modification 
required by paragraph (a) of this AD.

Reporting Requirement

    (c) Within 30 days after any false warning indication to the 
flightcrew from the hot detection system of the tail pipe harness of 
the engine nacelles occurs: Submit a report containing the 
information specified in paragraphs (c)(1), (c)(2), (c)(3), and 
(c)(4) of this AD to the Swedish Civil Aviation Authority 
(Luftfartsstyrelsen)--Attn: Mr. Christer Sundqvist, SAAB 340 
Certification Manager, SE-601 79, Norrk[ouml]ping, Sweden. Under the 
provisions of the Paperwork Reduction Act (44 U.S.C. 3501 et seq.), 
the Office of Management and Budget (OMB) has approved the 
information collection requirements contained in this AD and has 
assigned OMB Control Number 2120-0056.
    (1) The date and time, weather conditions, and phase of flight 
of the warning.
    (2) The action taken by the crew to address the warning (aborted 
takeoff, high speed/high energy abort requiring inspection, return 
for landing, in-flight diversion, declared emergency, ATC priority 
handling requested or given, or engine shutdown).
    (3) The action taken by maintenance to address/correct the 
warning.
    (4) Time-in-service on the airplane since the last inspection 
accomplished in accordance with paragraph (a) of this AD.

Alternative Methods of Compliance (AMOCs)

    (d)(1) In accordance with 14 CFR 39.19, the Manager, 
International Branch, ANM-116, Transport Airplane Directorate, FAA, 
is authorized to approve AMOCs for this AD.
    (2) Before using any AMOC approved in accordance with 14 CFR 
39.19 on any airplane to which the AMOC applies, notify the 
appropriate principal inspector in the FAA Flight Standards 
Certificate Holding District Office.


    Note 2: The subject of this AD is addressed in Swedish 
airworthiness directive 1-184, dated October 28, 2002.


    Issued in Renton, Washington, on June 19, 2006.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. E6-10014 Filed 6-23-06; 8:45 am]
BILLING CODE 4910-13-P