[Federal Register: December 13, 2006 (Volume 71, Number 239)]
[Proposed Rules]
[Page 74873-74878]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr13de06-21]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2006-23871; Directorate Identifier 2006-NE-01-AD]
RIN 2120-AA64
Airworthiness Directives; General Electric Company (GE) CF6-80C2
Turbofan Engines
AGENCY: Federal Aviation Administration (FAA), Department of
Transportation (DOT).
ACTION: Notice of proposed rulemaking (NPRM).
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SUMMARY: The FAA proposes to adopt a new airworthiness directive (AD)
for GE CF6-80C2 series turbofan engines. This proposed AD would require
replacing certain installed part number (P/N) and serial number (SN)
cast titanium weld-repaired forward engine mount platforms and cast
titanium forward mount yokes, with a forged titanium or a non-welded
cast titanium part. This proposed AD results from the discovery of
cracks, in a weld-repaired area on a forward engine mount platform and
a forward engine mount yoke, found during a fluorescent penetrant
inspection (FPI). These parts were weld-repaired during manufacture. We
are proposing this AD to prevent cracks in the forward engine mount
platform and forward engine mount yoke that could result in possible
separation of the engine from the airplane.
DATES: We must receive any comments on this proposed AD by January 12,
2007.
ADDRESSES: Use one of the following addresses to comment on this
proposed AD.
DOT Docket Web site: Go to http://dms.dot.gov and follow
the instructions for sending your comments electronically.
Government-wide rulemaking Web site: Go to http://www.regulations.gov
and follow the instructions for sending your
comments electronically.
Mail: Docket Management Facility; U.S. Department of
Transportation, 400 Seventh Street, SW., Nassif Building, Room PL-401,
Washington, DC 20590-0001.
Fax: (202) 493-2251.
Hand Delivery: Room PL-401 on the plaza level of the
Nassif Building, 400 Seventh Street, SW., Washington, DC, between 9
a.m. and 5 p.m., Monday through Friday, except Federal holidays.
You may examine the comments on this proposed AD in the AD docket
on the Internet at http://dms.dot.gov.
FOR FURTHER INFORMATION CONTACT: James Lawrence, Aerospace Engineer,
Engine Certification Office, FAA, Engine and Propeller Directorate, 12
New England Executive Park, Burlington, MA 01803; telephone (781) 238-
7176; fax (781) 238-7199.
SUPPLEMENTARY INFORMATION:
Comments Invited
We invite you to send us any written relevant data, views, or
arguments regarding this proposal. Send your comments to an address
listed under ADDRESSES. Include ``Docket No. FAA-2006-23871;
Directorate Identifier 2006-NE-01-AD'' in the subject line of your
comments. We specifically invite comments on the overall regulatory,
economic, environmental, and energy aspects of the proposed AD. We will
consider all comments received by the closing date and may amend the
proposed AD in light of those comments.
We will post all comments we receive, without change, to http://dms.dot.gov
, including any personal information you provide. We will
also post a report summarizing each substantive verbal contact with FAA
personnel concerning this proposed AD. Using the search function of the
DOT Web site, anyone can find and read the comments in any of our
dockets, including the name of the individual who sent the comment (or
signed the comment on behalf of an association, business, labor union,
etc.). You may review the DOT's complete Privacy Act Statement in the
Federal Register published on April 11, 2000 (65 FR 19477-78) or you
may visit http://dms.dot.gov.
[[Page 74874]]
Examining the AD Docket
You may examine the docket that contains the proposal, any comments
received, and any final disposition in person at the DOT Docket Office
between 9 a.m. and 5 p.m., Monday through Friday, except Federal
holidays. The Docket Office (telephone (800) 647-5227) is located on
the plaza level of the Department of Transportation Nassif Building at
the street address stated in ADDRESSES. Comments will be available in
the AD docket shortly after the Docket Management Facility receives
them.
Discussion
During an FPI inspection of the forward engine mount platform and
forward engine mount yoke, an air carrier found crack indications in
the forward engine mount platform and yoke, and reported the findings
to GE. An audit of GE's manufacturing records revealed 25 cast titanium
forward engine mount platforms, including the one found cracked, and 59
cast titanium forward engine mount yokes, had been weld-repaired at
manufacture in either the pylon thrust pin hole or in the pylon attach
bolt-hole region. Therefore, 25 cast titanium forward engine mount
platforms and 59 cast titanium forward engine mount yokes would be
affected by this proposed AD. Although the weld repairs were an
approved GE practice at the time, it has since been determined that the
welding results in cracking in critical areas of the forward engine
mount platforms and yokes. This condition, if not corrected, could
result in possible separation of the engine from the airplane.
FAA's Determination and Requirements of the Proposed AD
We have evaluated all pertinent information and identified an
unsafe condition that is likely to exist or develop on other products
of this same type design. We are proposing this AD, which would require
replacing certain installed P/N and SN cast titanium weld-repaired
forward engine mount platforms and cast titanium forward mount yokes
with a forged titanium or a non-welded cast titanium part.
Costs of Compliance
There are 25 engines in service that contain the substandard
forward engine mount platforms and 59 engines in service that contain
the substandard forward engine mount yokes. We estimate that this
proposed AD would affect 84 CF6-80C2 engines installed on airplanes of
U.S. registry. We estimate that it would take 34 work-hours per engine
to replace the weld-repaired cast titanium forward engine mount
platforms and the weld-repaired cast titanium forward engine mount
yokes. The average labor rate is $80 per work-hour. Required forward
engine mount parts would cost about $12,168 per engine. Required
forward engine mount yoke parts would cost about $39,560 per engine.
Based on these figures, we estimate the total cost of the proposed AD
to U.S. operators to be $2,866,720.
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 Findings
We have determined that this proposed AD would not have federalism
implications under Executive Order 13132. This proposed AD 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.
For the reasons discussed above, I certify that the 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. Would not have a significant economic impact, positive or
negative, on a substantial number of small entities under the criteria
of the Regulatory Flexibility Act.
We prepared a regulatory evaluation of the estimated costs to
comply with this proposed AD. See the ADDRESSES section for a location
to examine the regulatory evaluation.
List of Subjects in 14 CFR Part 39
Air transportation, Aircraft, Aviation safety, Safety.
The Proposed Amendment
Under the authority delegated to me by the Administrator, the
Federal Aviation Administration proposes to amend 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. The FAA amends Sec. 39.13 by adding the following new
airworthiness directive:
General Electric Company: Docket No. FAA-2006-23871; Directorate
Identifier 2006-NE-01-AD.
Comments Due Date
(a) The Federal Aviation Administration (FAA) must receive
comments on this airworthiness directive (AD) action by January 12,
2007.
Affected ADs
(b) None.
Applicability
(c) This AD applies to the following General Electric Company
(GE) turbofan engines with cast titanium assembly engine mount
platforms part numbers (P/Ns) 1292M13G06, 1301M28G08, 1459M70G07,
and 1846M24G04 and cast titanium assembly engine mount yokes P/Ns
9383M43G14 and 9383M43G16 installed.
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CF6-80C2A1........................... CF6-80C2A8............. CF6-80C2B4............. CF6-80C2B4F
CF6-80C2A2........................... CF6-80C2A5F............ CF6-80C2B6............. CF6-80C2B5F
CF6-80C2A3........................... CF6-80C2B1............. CF6-80C2B1F............ CF6-80C2B6F
CF6-80C2A5........................... CF6-80C2B2............. CF6-80C2B2F............ CF6-80C2B6FA
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[[Page 74875]]
These engines are installed on, but not limited to, Boeing 747,
Boeing 767, and Airbus A300-600 airplanes.
Unsafe Condition
(d) This AD results from the discovery of cracks in a forward
engine mount platform and a forward engine mount yoke found during
fluorescent penetrant inspection (FPI). We are issuing this AD to
prevent cracks in the forward engine mount platform and forward
engine mount yoke that could result in possible separation of the
engine from the airplane.
Compliance
(e) You are responsible for having the actions required by this
AD performed within the compliance times specified unless the
actions have already been done.
P/N and SN Weld-Repaired Forward Engine Mount Platforms and Forward
Engine Mount Yokes Requiring Replacement
(f) Table 1 of this AD lists the P/Ns and serial numbers (SNs)
of the weld-repaired forward engine mount platforms that have a weld
repair in a non-redundant area of the mount and must be replaced.
Table 1.--Weld-Repaired Forward Engine Mount Platforms Requiring
Replacement That Have a Weld Repair in a Non-Redundant Area of the
Mount.
------------------------------------------------------------------------
P/Ns SNs
------------------------------------------------------------------------
1292M13G06 or 1846M24G04................................... WACHH228
WACHH254
WACHH285
WACHH290
WACHH292
WACHH295
WACHH299
WACHH384
WACHH427
WACHH440
WACHH604
1301M28G08................................................. WACAR292
WACAR354
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(g) Table 2 of this AD lists the P/Ns and SNs of the weld-
repaired forward engine mount platforms that have a weld repair in a
redundant area of the mount. Because it is impossible to detect
whether the mount is operating on the redundant feature, each of
these mounts must be replaced. The compliance time for mounts in
this category can be longer than for the mounts listed in Table 1 of
this AD.
Table 2.--Weld-Repaired Forward Engine Mount Platforms Requiring
Replacement That Have a Weld Repair in a Redundant Area of the Mount
------------------------------------------------------------------------
P/Ns SNs
------------------------------------------------------------------------
1292M13G06 or 1846M24G04................................... WACHH173
WACHH189
WACHH274
WACHH278
WACHH314
WACHH325
WACHH486
1301M28G08................................................. WACAR294
WACAR304
WACAR353
WACAR372
1459M70G07................................................. MTXT1282
------------------------------------------------------------------------
(h) Table 3 of this AD lists the P/Ns and SNs of the weld-
repaired forward engine mount yokes that have a weld repair in a
redundant area of the yoke. Because it is impossible to detect
whether the mount yoke is operating on the redundant feature, each
of these mount yokes must be replaced. The compliance time for
mounts in this category can be longer than for the mounts listed in
Table 1 of this AD.
Table 3.--Weld-Repaired Forward Engine Mount Yokes Requiring Replacement
That Have a Weld Repair in a Non-Redundant Area of the Yoke
------------------------------------------------------------------------
P/Ns SNs
------------------------------------------------------------------------
9383M43G14................................................. WACV0388
WACV0394
WACV0405
WACV0406
WACV0477
WACV0498
WACV0529
WACV0556
WACV0579
WACV0581
WACV0582
WACV0600
WACV0605
WACV0617
WACV0625
WACV0627
WACV0633
WACV0645
WACV0683
WACV0703
WACV0733
WACV0737
WACV0759
WACV0775
WACV0791
WACV0799
WACV0875
WACV0883
WACV0885
WACV0909
WACV1097
WACV1615
WACV1713
WACV1753
WACV1797
WACV1867
WACV1987
WACV2131
WACV2159
WACV2185
WACV2343
WACV2511
WACV2695
WACV2707
WACV2881
WACV2899
9383M43G16................................................. WACV0511
WACV0515
WACV0518
WACV0540
WACV0542
WACV0571
WACV0689
WACV0721
WACV0727
WACV0730
WACV0786
WACV0816
WACV0954
------------------------------------------------------------------------
(i) GE advises that forward engine mount platform, P/Ns
1292M13G06 and 1846M24G04, are the same, except that P/N 1846M24G04
incorporates a previously approved field rework. This rework allows
the thrust pin hole in the forward engine mount platform to be bored
out to accept installation of an oversized thrust pin. GE cannot
identify which SN goes with which P/N, but all SNs are affected.
Welded Cast Titanium Forward Engine Mount Platform and Forward Engine
Mount Yoke Removal
(j) If the P/N and SN of the forward engine mount platform
listed in Table 1 and Table 2 and the forward engine mount yoke
listed in Table 3 of this AD are not installed on the engine, no
further action is necessary.
(k) If the P/N and SN of the forward engine mount platform
listed in Table 1 of this AD is installed on the engine:
(1) Remove the forward engine mount platform from the engine
within 500 cycles or 6 months, after the effective date of this AD,
whichever occurs first.
(2) Information for removal of the forward engine mount platform
from the engine can be found in the CF6-80C2 Engine Manual, 72-00-
01, Disassembly.
(l) If the P/N and SN of the forward engine mount platform
listed in Table 2 of this AD is installed on the engine:
(1) Remove the forward engine mount platform at the next shop
visit, or within 4,800 cycles after the effective date of this AD,
whichever occurs first.
(2) Information for removal of the forward engine mount yoke can
be found in the CF6-80C2 Engine Manual, 72-00-01, Disassembly.
(m) If the P/N and SN of the forward engine mount yoke listed in
Table 3 of this AD is installed on the engine:
[[Page 74876]]
(1) Remove the forward engine mount yoke at the next shop visit,
or within 4,800 cycles after the effective date of this AD,
whichever occurs first.
(2) Information for removal of the forward engine mount yoke can
be found in the CF6-80C2 Engine Manual, 72-00-01, Disassembly.
(n) Replace the affected forward engine mount platform and or
the affected forward engine mount yoke with a non-weld-repaired cast
titanium forward engine mount platform and or the forward engine
mount yoke or a forged titanium forward engine mount platform or a
forged titanium forward engine mount yoke.
(o) Information for installing the forward engine mount platform
and forward engine mount yoke can be found in the CF6-80C2 Engine
Manual, 72-00-01, Assembly.
(p) Location of the forward engine mount platform and forward
engine mount yoke and SN are illustrated in the following Figure 1.
BILLING CODE 4910-13-P
[[Page 74877]]
[GRAPHIC] [TIFF OMITTED] TP13DE06.002
BILLING CODE 4910-13-C
(q) After the effective date of this AD, do not install a weld-
repaired, cast forward engine mount platform or a weld-repaired,
[[Page 74878]]
cast forward engine mount yoke in any engine.
Alternative Methods of Compliance
(r) The Manager, Engine Certification Office, has the authority
to approve alternative methods of compliance for this AD if
requested using the procedures found in 14 CFR 39.19.
Issued in Burlington, Massachusetts, on December 7, 2006.
Robert Ganley,
Acting Manager, Engine and Propeller Directorate, Aircraft
Certification Service.
[FR Doc. 06-9674 Filed 12-12-06; 8:45 am]
BILLING CODE 4910-13-P