[Federal Register: September 29, 2004 (Volume 69, Number 188)]
[Rules and Regulations]
[Page 58043-58047]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr29se04-5]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 2002-NM-126-AD; Amendment 39-13808; AD 2004-20-03]
RIN 2120-AA64
Airworthiness Directives; Bombardier Model DHC-8-101, -102, -103,
-106, -201, -202, -301, -311, and -315 Airplanes
AGENCY: Federal Aviation Administration, DOT.
ACTION: Final rule.
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SUMMARY: This amendment adopts a new airworthiness directive (AD),
applicable to all Bombardier Model DHC-8-101, -102, -103, -106, -201, -
202, -301, -311, and -315 airplanes. This amendment requires a detailed
inspection of the wing leading edge de-icer boots to determine if they
comply with certain patch limits in the critical zone; and corrective
action, if necessary. This action is necessary to prevent reduced
aerodynamic smoothness of the wing leading edge de-icer boots and
possible reduced stall margin, which could result in a significant
increase in stall speeds, leading to a possible stall prior to
activation of the stall warning. This action is intended to address the
identified unsafe condition.
DATES: Effective November 3, 2004.
ADDRESSES: The service information referenced in this AD may be
obtained from Bombardier, Inc., Bombardier Regional Aircraft Division,
123 Garratt Boulevard, Downsview, Ontario M3K 1Y5, Canada. 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 FAA, New York Aircraft Certification
Office, 1600 Stewart Avenue, suite 410, Westbury, New York.
FOR FURTHER INFORMATION CONTACT: Ezra Sasson, Aerospace Engineer,
Systems and Flight Test Branch, ANE-172, FAA, New York Aircraft
Certification Office, 1600 Stewart Avenue, suite 410, Westbury, New
York, 11590; telephone (516) 228-7320; fax (516) 794-5531.
SUPPLEMENTARY INFORMATION: A proposal to amend part 39 of the Federal
Aviation Regulations (14 CFR part 39) to include an airworthiness
directive (AD) that is applicable to all Bombardier Model DHC-8-101, -
102, -103, -106, -201, -202, -301, -311, and -315 airplanes was
published in the Federal Register on December 18, 2003 (68 FR
[[Page 58044]]
70469). That action proposed to require a detailed inspection of the
wing leading edge de-icer boots to determine if they comply with the
patch size and/or patch number limits in the critical zone as defined
in the aircraft maintenance manual; and corrective action, if
necessary.
Comments
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 Reference New Temporary Revisions
One commenter, an airplane operator, states that the proposed rule
requires inspections using limits that were published in the aircraft
maintenance manual (AMM) in October 2001. The commenter notes that
these limits have all been revised, and now all have revision dates in
2003. In addition, the commenter states that if the new limits are not
included in the proposed rule, then operators would be required to find
and re-insert the older data into the AMM, which would negate two years
of progress in maintaining the leading edge de-icer boots.
We infer that the commenter is requesting that we use the revisions
that were published in 2003. We partially agree with the commenter's
request. We have not revised paragraph (a) of the final rule to include
the new AMM revisions because another suggestion by the same commenter
(see ``Request to Insert Limits Directly Into Final Rule'') makes
including a reference to these revisions in that paragraph unnecessary.
However, we have listed these revisions in new Table 3 of new paragraph
(c)(3) of the final rule (see ``Explanation of New Paragraph (c)(3) of
the Final Rule''). In addition, because the requirements in the new
revisions are less restrictive, those operators who have complied with
the limits published in the 2001 revisions are still compliant with the
intent of the final rule. Therefore, we have added new Table 4 and new
paragraph (e) to the final rule that gives credit to operators who have
accomplished the required actions in accordance with the 2001 revisions
of the AMM.
Request To Insert Limits Directly Into Final Rule
The same commenter suggests that, rather than referencing the AMMs
for the necessary limits in paragraph (a) of the proposed rule, the FAA
insert the necessary limits directly into paragraph (a). The commenter
states that the chapters of the AMM referenced in paragraph (a) of the
proposed rule contain significantly more information than apply to the
patch limits that affect the stall margin. The commenter further states
that the limits can be addressed concisely and, therefore, proposes
that we specify the actual acceptance criteria in the proposed rule.
The commenter states that this would allow operators to revise the AMMs
as necessary to provide current information, yet would still mandate
the limits that are required. The commenter also suggests that if
paragraph (a) is changed as suggested, all references to the AMM in the
proposed rule be changed to refer to paragraph (a).
We agree with the commenter's request to change paragraph (a) of
the final rule and all references to it in the final rule for the
stated reasons. Paragraph (a) has been revised to more clearly define
the term, ``patch limits'' and to specify those specific limits.
Additionally, all references to the AMM have been changed to refer to
paragraph (a). We also have revised the Summary of the final rule to
remove the reference to the limits in the critical zone ``as defined in
the AMM.''
Request To Allow Ferry Flights
The same commenter requests that we add a new paragraph to the
final rule regarding ferry flights. The proposed paragraph would allow
operators of any airplane that has de-icer boots that do not meet the
AMM limits to ferry the airplane to a location where repairs can be
made, provided the airplane is operated under the limits in Table 2 of
the proposed rule. We infer that the operator would like the
flexibility to move airplanes to convenient locations for repair
without the need to request a special flight permit.
We partially agree with the commenter's request to add a paragraph
regarding ferry flights to the final rule. On July 10, 2002, we issued
a new version of 14 CFR part 39 (67 FR 47997, July 22, 2002), which
governs the FAA's airworthiness directives system. The regulation now
includes material that relates to special flight permits for ferry
flights. As stated in 14 CFR 39.23: ``[T]he operations specifications
giving some operators authority to operate include a provision that
allow(s) them to fly their aircraft to a repair facility to do the work
required by an airworthiness directive. If you do not have this
authority, the local Flight Standards District Office of FAA may issue
you a special flight permit unless the airworthiness directive states
otherwise. To ensure aviation safety, FAA may add special requirements
for operating your aircraft to a place where the repairs or
modifications can be accomplished. FAA may also decline to issue a
special flight permit in particular cases if we determine you cannot
move the aircraft safely.'' If an operator does not have the specified
authority and requires a special flight permit, we will evaluate any
request for a special flight permits on a case by case basis at the
time of the request. We do not find it necessary to change the final
rule in this regard.
Request To Address Varying Levels of Degradation
Another commenter is concerned about varying levels of degradation
of the de-icer boots in the affected fleet of airplanes. The commenter
states that there may be airplanes in operation that do not exceed the
limits in the proposed rule, but still have leading edge de-icer boots
that are in a state of repair that may degrade the aerodynamic
performance of the wing more than other airplanes with less damage.
We infer that the commenter is requesting that we revise the
proposed rule to address airplanes that carry varying levels of
degradation. We do not agree. The limits in the final rule address the
worst-case patch size and patch limits in the wing critical zone. In
devising these limits, we assessed the amount of damage that is
acceptable for safe flight without the performance penalties cited in
Table 2 of this AD. These limits take into account the airplane
aerodynamic characteristics and the smoothness of the boots. We have
not changed the final rule in this regard.
Request To Clarify Applicability of Performance Penalties
The same commenter states that it is unclear if the performance
penalties cited in Table 2 of the proposed rule are to be included only
in the airplane flight manuals (AFM) of airplanes that have boot
patches that exceed the patch-number limits, or if the penalties will
be applicable to all Model DHC-8 airplanes in a given operator's fleet
until all of the proposed inspections and replacements are completed.
From these statements, we infer that the commenter is requesting
that we clarify the applicability of the performance penalties listed
in Table 2 of the proposed rule. We do not agree that is necessary to
change the applicability of the final rule to make this clarification.
As stated in paragraph (c) of the final rule, the performance penalties
apply only to airplanes that require corrective actions. Airplanes that
require corrective actions are those
[[Page 58045]]
that have boot patches that exceed the limits specified in the AMM. We
have not changed the final rule in this regard. However, we have
clarified paragraphs (c) and (c)(1) of the final rule based on the
addition of a new paragraph (c)(3) to the final rule. These changes are
described below in ``Explanation of New Paragraph (c)(3) of the Final
Rule'' and ``Explanation of Clarifications Made in Paragraphs (c) and
(c)(1) of the Final Rule.''
Request To Reduce Compliance Time for Replacements
The same commenter requests that we reduce the 24-month compliance
time replacing the wing de-icer boots, which is specified in paragraph
(c)(2) of the proposed rule. The commenter states that a 24-month
compliance time could allow some airplanes to be exposed to icing
conditions for up to three icing seasons.
We do not agree with the request for a shorter compliance time in
paragraph (c)(2) of the final rule. In developing the proposed
compliance time, we considered the fact that there have been no
occurrences of stall problems in the past, and that an airplane that
requires corrective action is bound to the performance penalties in
Table 2 of the final rule during this 24-month period. We determined
that the compliance is appropriate in consideration of the safety
implications, the average utilization rate of the affected fleet, the
practical aspects of an orderly inspection of the fleet, and the
availability of required modification parts. We have not changed the
final rule in this regard.
Request for Ongoing Monitoring Program
The same commenter requests that there be a clearly delineated
ongoing program included in the proposed rule to monitor the number and
size of patches on the new boots in order to stay in compliance with
AMM limits. The commenter is concerned that the proposed rule is not
clear about how operators should monitor the number and size of boot
patches on the new boots after replacement, and still stay in
compliance with the AMM limits.
We do not agree that it is necessary to delineate a monitoring
program. Paragraph (d) of the final rule states that ``as of the
effective date of this AD, no person may install--on any airplane--a
de-icer boot patch in the critical zone of the wing de-icer boots that
exceeds the patch limits specified in paragraph (b) of this AD.''
Paragraph (d) of this AD is intended to prevent the installation of any
patches beyond the specified limits. Therefore, after the boot
replacements have been made, it is unnecessary to institute an ongoing
monitoring program. We have not changed the final rule in this regard.
Conclusion
After careful review of the available data, including the comments
noted above, we have determined that air safety and the public interest
require the adoption of the rule with the changes described previously.
We have determined that these changes will neither increase the
economic burden on any operator nor increase the scope of the AD.
Explanation of New Paragraph (c)(3) of the Final Rule
Paragraph (c)(3) of the final rule gives operators two methods to
choose from for replacing the de-icer boots:
In accordance with a method approved by either the
Manager, Systems and Flight Test Branch, ANE-172, FAA, New York
Aircraft Certification Office; or
In accordance with a method approved by Transport Canada
Civil Aviation (or its delegated agent).
The paragraph further states that the applicable chapter of the AMM
referenced in Table 3 of paragraph (c)(3) of the final rule is ``one
approved method.''
We find that allowing operators to accomplish the actions according
to one of the cited methods will not impose additional burden for
operators to comply with the actions in the AD.
Explanation of Clarifications Made in Paragraphs (c) and (c)(1) of the
Final Rule
Adding paragraph (c)(3) to this final rule made it necessary to
clarify the statements in paragraphs (c) and (c)(1) of the final rule.
Paragraph (c) of the final rule now specifically requires operators of
airplanes that require corrective actions to do the actions in
paragraphs (c)(1) and (c)(2). Paragraph (c)(1) of the final rule now
also refers to airplanes that have findings that exceed the patch
limits in accordance with paragraph (b)(2) of the final rule.
Cost Impact
We estimate that 200 airplanes of U.S. registry will be affected by
this AD, that it will take approximately 2 work hours per airplane to
accomplish the required actions, and that the average labor rate is $65
per work hour. Based on these figures, the cost impact of the AD on
U.S. operators is estimated to be $26,000, or $130 per airplane.
The cost impact figure discussed above is 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. 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 adopted herein will 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 final rule does not have federalism
implications under Executive Order 13132.
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:
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:
[[Page 58046]]
2004-20-03 Bombardier, Inc. (Formerly de Havilland, Inc.): Amendment
39-13808. Docket 2002-NM-126-AD.
Applicability: All Model DHC-8-101, -102, -103, -106, -201, -
202, -301, -311, and -315 airplanes; certificated in any category.
Compliance: Required as indicated, unless accomplished
previously.
To prevent reduced aerodynamic smoothness of the wing leading
edge de-icer boots and possible reduced stall margin, which could
result in a significant increase in stall speeds, leading to a
possible stall prior to activation of the stall warning; accomplish
the following:
Critical Zone Limits and Patch Limits
(a) For the purposes of this AD, the ``critical zone'' and
``patch limits'' are defined in accordance with paragraphs (a)(1)
and (a)(2) of this AD.
(1) The wing ``critical zone'' is the area of the leading edge
assemblies that represents 3% of the chord. The critical zone may be
found by measuring from the aft edge of a leading edge assembly,
going forward on the upper surface and lower surface. The
measurements identify the aft limits of the critical zone, as shown
in Table 1 of this AD.
Table 1.--Limits of Critical Zone
[In inches]
------------------------------------------------------------------------
Measured along Measured along
Spanwise region lower surface upper surface
------------------------------------------------------------------------
YW63.00-YW139.00........................ 13.0 13\1/4\
YW202.00-YW288.00....................... 10\1/4\ 10\1/2\
YW288.00-YW326.00....................... 9\1/2\ 9\3/4\
YW326.00-YW405.00....................... 8.0 8\1/4\
YW405.00-YW790.00....................... 61/2 6\3/4\
YW490.00-YW520.00 (series 300 only)..... 6\1/4\ 6\1/2\
------------------------------------------------------------------------
(2) ``Patch limits'' regarding the number and size of patches
are defined as follows:
(i) Three small 1\1/4\ x 2\1/2\ inch (3.17 x 6.35 centimeters
(cm)) patches for each 12-inch square (929.0 square cm).
(ii) Two medium 2\1/2\ x 5 inch (6.35 x 12.70 cm) patches for
each 12-inch square.
(iii) One large 5 x 10 inches (12.70 x 25.40 cm) patch for each
12-inch square.
(3) ``Patch limits'' regarding the number or total percentage of
patches that may be concentrated together in one area of the wing
de-icer boot are defined as follows: The spanwise length of each
patch in the critical zone, added together, may be no greater than
62.5% of the total length of the boot. A patch is considered to be
in the critical zone if any part of the patch is in the critical
zone. Patches may be concentrated together in one area of the boot
as long as one patch is not applied over part of another patch;
patches may not overlap.
Detailed Inspection
(b) Within 60 days after the effective date of this AD: Perform
a detailed inspection of the wing leading edge de-icer boots to
determine if the de-icer boots comply with the patch limits in the
wing critical zone as defined in paragraph (a) of this AD.
Note 1: For the purposes of this AD, a detailed inspection is
defined as: ``An intensive visual examination of a specific
structural area, system, installation, or assembly to detect damage,
failure, or irregularity. Available lighting is normally
supplemented with a direct source of good lighting at intensity
deemed appropriate by the inspector. Inspection aids such as mirror,
magnifying lenses, etc., may be used. Surface cleaning and elaborate
access procedures may be required.''
(1) If all de-icer boots are within the patch limits in the
critical zone, no further action is required by this paragraph.
(2) If any de-icer boot exceeds the patch limits in the critical
zone, accomplish the corrective actions required by paragraph (c) of
this AD.
Corrective Actions
(c) For airplanes that require corrective actions, as described
in paragraph (b)(2) of this AD, do the actions in paragraphs (c)(1)
and (c)(2) of this AD.
(1) Before further flight after the finding of any de-icer boot
that exceeds the patch limits per paragraph (b)(2) of this AD:
Insert the contents of Table 2 of this AD in the Limitations Section
of the aircraft flight manual (AFM) and advise flightcrews to comply
with the performance penalties in Table 2 of this AD.
(2) Within 24 months after the effective date of this AD,
replace all wing de-icer boots that exceed the patch limits in the
critical zone as defined in paragraph (a) of this AD, with new de-
icer boots, per paragraph (c)(3) of this AD. Remove the contents of
Table 2 of this AD from the AFM, and terminate the requirements to
comply with the performance penalties after all replacements are
accomplished.
Table 2.--Performance Penalties
------------------------------------------------------------------------
AFM limits with de-ice boot
patch limits exceeded (Note:
AFM sections Flap settings as applicable to
aircraft model)
------------------------------------------------------------------------
T/O Speed: Sub-Section 5-2:
V1, Vr & V2........................ Add: 5 kt (flap 0[deg]); 5 kt
(flap 5[deg]); 5 kt (flap
10[deg]); 5 kt (flap 15[deg]).
Final T/O Climb Speed.............. Add: 5 kt (flap 0[deg]).
T/O WAT Limit: Sub-Section 5-3:
Note: Weight reduction not required Subtract: 18 kg, 400 lb. (flap
when limited by maximum structural 0[deg]); 90 kg, 200 lb. (flap
weight. 5[deg]); No change (flap
10[deg]); No change (flap
15[deg]).
T/O Climb: Sub-Section 5-4:
1st Seg. Gradient.................. Subtract: 0.008 (flap 0[deg]);
0.004 (flap 5[deg]); 0.004
(flap 10[deg]); 0.004 (flap
15[deg]).
2nd Seg. Gradient.................. Subtract: 0.005 (flap 0[deg]);
0.002 (flap 5[deg]); 0.002
(flap 10[deg]); 0.002 (flap
15[deg]).
Final Seg. Gradient................ Subtract: 0.009 (flap 0[deg]).
T/O Field Length: Sub-Section 5-5:
TOR, TOD & ASD..................... Add: 16% (flap 0[deg]); 16%
(flap 5[deg]); 16% (flap
10[deg]); 16% (flap 15[deg]).
Net T/O Flight Path: Sub-Section 5-6:
Ref Gradient....................... Subtract: 0.005 (flap 0[deg]);
0.002 (flap 5[deg]); 0.002
(flap 10[deg]); 0.002 (flap
15[deg]).
[[Page 58047]]
4th Seg. Net Gradient.............. Subtract: 0.012 (flap 0[deg]).
Flap Retraction Initiation Speed... Add: 5 kt (flap 5[deg]); 5 kt
(flap 10[deg]); 5 kt (flap
15[deg]).
Enroute Climb Data: Sub-Section 5-7:
Enroute Climb Speed................ Add: 5 kt.
Net Climb Gradient................. Subtract: 0.004.
OEI-Climb Ceiling.................. Subtract: 1,200 ft.
Landing Speed: Sub-Section 5-8:
Approach, Go-around & Vref......... Add: 5 kt (flap 5[deg]); 5 kt
(flap 10[deg]); 5 kt (flap
15[deg]); 5 kt (flap 35[deg]).
Landing WAT Limit: Sub-Section 5-9:
Note: Weight reduction not required Subtract: 860 kg, 1,900
when limited by maximum structural lb.(flap 10[deg]); 225 kg, 500
weight. lb. (flap 15[deg]); 180 kg,
400 lb. (flap 35[deg]).
Landing Climb Data: Sub-Section 5-10:
Approach Gross Climb Gradient...... Subtract: 0.010 (flap 5[deg]);
0.003 (flap 10[deg]); 0.002
(flap 15[deg]).
Balked Landing Gross Climb Gradient Subtract: 0.035 (flap 10[deg]);
0.017 (flap 15[deg]); 0.016
(flap 35[deg]).
Landing Field Length: Sub-Section 5-11: Add: 23% (flap 10[deg]); 16%
(flap 15[deg]); 10% (flap
35[deg]).
Brake Energy: Sub-Section 5-12:
Accel/Stop B.E..................... Add: 7% (flap 0[deg]); 7% (flap
5[deg]); 7% (flap 10[deg]);
(flap 15[deg]).
Landing B.E........................ Add: 30% (flap 10[deg]); 20%
(flap 15[deg]); 8% (flap
35[deg]).
------------------------------------------------------------------------
(3) Do the replacements described in paragraph (c)(2) of this AD
per a method approved by either the Manager, Systems and Flight Test
Branch, ANE-172, FAA, New York Aircraft Certification Office (ACO),
or Transport Canada Civil Aviation (TCCA) (or its delegated agent).
The applicable chapter of the applicable Bombardier Aircraft
Maintenance Manual (AMM) or in the temporary revision listed in
Table 3 of this AD is one approved method.
Table 3.--AMM Reference
--------------------------------------------------------------------------------------------------------------------------------------------------------
Product support Temporary revision
Model AMM manual (PSM) Chapter (TR) Date
--------------------------------------------------------------------------------------------------------------------------------------------------------
DHC-8-101, -102, -103, and -106.. Series 100.......... 1-8-2............... 30-10-48............ TR 30-35........... October 28, 2003.
DHC-8-201, and -202.............. Series 200.......... 1-82-2.............. 30-12-00............ TR 30-025.......... August 28, 2003.
DHC-8-301, -311, and -315........ Series 300.......... 1-83-2.............. 30-10-48............ TR 30-25........... October 21, 2003.
--------------------------------------------------------------------------------------------------------------------------------------------------------
Parts Installation
(d) As of the effective date of this AD, no person may install--
on any airplane--a de-icer boot patch in the critical zone of the
wing de-icer boots that exceeds the patch limits specified in
paragraph (a) of this AD.
Actions Accomplished Previously
(e) Actions that were accomplished before the effective date of
this AD per the applicable chapters of the following AMMs is
acceptable for compliance with the corresponding action in this AD:
DHC-8-101, -102, and -106 Series 100 AMM, PSM 1-8-2, Chapter 30-10-
48, Revision 49, dated October 3, 2001; DHC-8-201, and -202 Series
200 AMM, PSM 1-82-2, Chapter 30-12-00, Revision 11, dated October
19, 2001; and Temporary Revision 30-21 to the DHC-8-301, -311, and -
315 Series 300 AMM, PSM 1-83-2, Chapter 30-10-48, dated October 30,
2001.
Alternative Methods of Compliance
(f) In accordance with 14 CFR 39.19, the Manager, New York ACO,
FAA, is authorized to approve alternative methods of compliance for
this AD.
Note 2: The subject of this AD is addressed in Canadian
airworthiness directive CF-2001-43, dated November 23, 2001.
Effective Date
(g) This amendment becomes effective on November 3, 2004.
Issued in Renton, Washington, on September 16, 2004.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 04-21646 Filed 9-28-04; 8:45 am]
BILLING CODE 4910-13-P