Airworthiness directives: Pratt & Whitney,
[Federal Register: March 1, 2007 (Volume 72, Number 40)]
[Proposed Rules]
[Page 9276-9281]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr01mr07-16]
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
[Docket No. FAA-2005-23072; Directorate Identifier 2005-NE-38-AD]
RIN 2120-AA64
Airworthiness Directives; Pratt & Whitney JT9D-7R4 Turbofan Engines
AGENCY: Federal Aviation Administration (FAA), Department of Transportation (DOT).
ACTION: Notice of proposed rulemaking (NPRM).
SUMMARY: The FAA proposes to supersede an existing airworthiness directive (AD) for Pratt & Whitney (PW) JT9D-7R4 turbofan engines. That AD currently requires inspection of the blade root thickness of 1st stage fan blades identified by part number (P/N) and serial number (SN) in the AD. This proposed AD would require the same actions but would correct 12 P/Ns, add 10 part SNs, and add the definition of next fan blade exposure to the compliance section. This proposed AD results from the discovery of inaccurate part quantity, part numbers, and serial numbers used in AD 2005-26-09. We are proposing this AD to prevent 1st stage fan blade fracture and uncontained engine failure, resulting in possible damage to the airplane.
DATES: We must receive any comments on this proposed AD by April 30, 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.
FOR FURTHER INFORMATION CONTACT: Kevin Donovan, Aerospace Engineer, Engine Certification Office, FAA, Engine and Propeller Directorate, 12 New England Executive Park, Burlington, MA 01803-5299; telephone (781) 238-7743, fax (781) 238-7199.
SUPPLEMENTARY INFORMATION:
Comments Invited
We invite you to send any written relevant data, views, or arguments regarding this proposal. Send your comments to an address listed under ADDRESSES. Include ``Docket No. FAA-2005-23072; Directorate Identifier 2005-NE-38-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 DMS 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.
Examining the AD Docket
You may examine the docket that contains the proposal, any comments received and any final disposition in person at the Docket Management Facility 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 DMS receives them.
Discussion
On December 16, 2005, the FAA issued AD 2005-26-09, Amendment 39- 14430 (70 FR 76381, December 27, 2005). That AD requires inspection of the blade root thickness of 1st stage fan blades identified by P/N and SN. That AD was the result of a report of a repair station that created an unapproved repair on 1st stage fan blades. That condition, if not corrected, could result in 1st stage fan blade fracture and uncontained engine failure, resulting in possible damage to the airplane.
Actions Since AD 2005-26-09 Was Issued
Since AD 2005-26-09 was issued, we received comments on the AD requesting clarification. We considered those requests and have changed the compliance section in this proposed AD for clarification. We also found and corrected 12 incorrect P/Ns, and added 10 part SNs of affected 1st stage fan blades to Table 1 of this proposed AD. The comments and affected P/Ns and SNs are also discussed below.
[[Page 9277]]
Request To Clarify ``At the Next 1st Stage Fan Blade Exposure''
Two air carriers request that we clarify ``at the next 1st stage fan blade exposure,'' to prevent any in-service disruptions or delays. The commenter further states that the 1st stage fan blades can be exposed when:
Some 1st stage fan blades are replaced due to in-service foreign object damage;
A 1st stage fan hub is replaced and the same 1st stage fan blades are reused; and
At shop visit when 1st stage fan blades are removed from the fan hub for cause or work scope.
We agree with adding a paragraph to the proposed AD which defines next 1st stage fan blade exposure. We have defined it as when any 1st stage fan blade is removed from the engine; or when the 1st stage fan hub is removed from the engine.
Suggestion To Report When Finding Affected 1st Stage Fan Blades
Air Canada suggests that operators finding any affected 1st stage fan blades should report back to the FAA. The commenter states that by requiring this reporting, all 520 of the blades can then be accounted for, and the FAA can close the AD. The commenter is also concerned that if some blades cannot be accounted for, such as blades already scrapped, misplaced, or shelved, then the AD will never be closed, and operators will be forced to verify the AD indefinitely at every 1st stage fan blade installation.
We do not agree. This proposed AD requires a onetime inspection for a specific population of 1st stage fan blades. If an operator has inspected and verified a certain set of 1st stage fan blades in accordance with the proposed AD, then at the next 1st stage fan blade exposure, only replacement blades that are listed in Table 1 of the proposed AD will require inspection and verification.
Request To Clarify or Remove Paragraph (e)
Air Canada states that compliance paragraph (e) mentions that the AD must be performed within the compliance times specified, but there are no times specified. The commenter requests this instruction be removed or clarified.
We partially agree. We revised the compliance times for clarification in the proposed AD.
Comment That ``At Exposure'' Limit Is Not a Practical Limit
ABX AIR claims that the ``at exposure'' limit in the AD is not practical. They said that ``at exposure'' will require the operators to set up a special inspection schedule to accomplish this onetime inspection which is not suitable for fleet operators.
We partially agree. Inspecting the affected parts at the next 1st stage fan blade exposure is sufficient. It is not necessary for operators to set up a special inspection schedule since this inspection does not impact the FAA-approved maintenance program procedures. However, for clarification, we added a definition for ``next first stage fan blade exposure'' to the proposed AD.
Request To Clarify ``Before Installing the 1st Stage Fan Blades''
ABX AIR requests that we clarify ``before installing the 1st stage fan blades'' in paragraph (f). ABX believes the AD should contain a concise clarifying statement such as: ``After the active date of this AD, no person may install, on any airplane, any blade listed in Table 1 of this AD unless the actions of this AD have already been accomplished.''
We agree. We added a prohibition statement that states that after the effective date of this (proposed) AD, do not install any 1st stage fan blades listed in Table 1 of this AD on any airplane, unless the actions of this AD have been done to the 1st stage fan blades.
P/Ns Corrected, and P/Ns and SNs Added
Since we issued AD 2005-26-09, we found and corrected 12 incorrect P/Ns, and added 10 part SNs of affected 1st stage fan blades in Table 1 of this proposed AD. The corrected numbers are as follows:
Corrected P/ Incorrect P/Ns
Ns
SNs
5001341-023......................... 5001341-022 JW2313 5001341-024......................... 5001341-022 JW2498 5001341-025......................... 5001341-022 JW2541 5001341-026......................... 5001341-022 JW2560 5001341-027......................... 5001341-022 JW2589 5001341-028......................... 5001341-022 JW2639 5001341-029......................... 5001341-022 JW2760 5001341-030......................... 5001341-022 JW2792 5001341-031......................... 5001341-022 MO579 5001341-032......................... 5001341-022 MG2825 5001341-033......................... 5001341-022 MG5477 5001341-034......................... 5001341-022 ND5917
The added part SNs are as follows:
PNs
Added SNs
5001341-022..........................
JW4713 5001341-022..........................
MG6743 5001341-022..........................
ND6924 831021-003...........................
ND9177 831021-003...........................
ND9496 831021-003...........................
NS7894 831021-003...........................
NS8559 831021-003...........................
NS9072 804121...............................
PX3805 804121...............................
PX4266
Conclusion
We have carefully reviewed the available data, including the comments received, and determined that air safety and the public interest require proposing this AD 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 proposed AD.
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. For that reason, we are proposing this AD, which would require:
Checking the 1st stage fan blade for a circled, letter I, on the approved marking area of the outboard side of the blade platform. If the blade has this marking, no further action is required.
Removing 1st stage fan blades without a circled, letter I, on the approved marking area of the outboard side of the blade platform if installed; and
Inspecting the 1st stage fan blade root thickness; and
Returning to service 1st stage fan blades that pass the inspection, after properly marking the blade.
Costs of Compliance
We estimate that this proposed AD would affect 531 1st stage fan blades installed on JT9D-7R4 turbofan engines installed on airplanes of U.S. registry. We also estimate that it would take about 0.5 work-hour per 1st stage fan blade to perform the proposed actions, and that the average labor rate is $80 per work-hour. Based on these figures, we estimate the total cost of the proposed AD to U.S. operators to be $21,240.
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.
[[Page 9278]]
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 AD:
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 removing Amendment 39-14430 (70 FR 76381, December 27, 2005), and by adding a new airworthiness directive to read as follows:
Pratt & Whitney: Docket No. FAA-2005-23072; Directorate Identifier 2005-NE-38-AD.
Comments Due Date
(a) The Federal Aviation Administration (FAA) must receive comments on this airworthiness directive (AD) action by April 30, 2007.
Affected ADs
(b) This AD supersedes AD 2005-26-09.
Applicability
(c) This AD applies to Pratt & Whitney (PW) JT9D-7R4 turbofan engines. These engines are installed on, but not limited to, Airbus A300 and A310, and Boeing 747 and 767 airplanes.
Unsafe Condition
(d) This AD results from the discovery of inaccurate part quantity, part numbers, and serial numbers used in AD 2005-26-09. We are issuing this AD to prevent 1st stage fan blade fracture and uncontained engine failure, resulting in possible damage to 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.
(f) For 1st stage fan blades that are listed by part number (P/ N) and serial number (SN) in Table 1 of this AD, do the following:
Table 1.--Affected 1st Stage Fan Blades
P/Ns
SNs
5001341-022................................. JW2804 5001341-022................................. JW0354 5001341-022................................. ND5746 5001341-022................................. ND5770 5001341-022................................. JW3992 5001341-022................................. ND8615 5001341-022................................. JW0442 5001341-022................................. JW2317 5001341-022................................. ND8631 5001341-022................................. ND8635 5001341-022................................. JW4624 5001341-022................................. NE0394 5001341-022................................. NE0153 5001341-022................................. NN8054 5001341-022................................. JW4693 5001341-022................................. ND7304 5001341-022................................. MG6108 5001341-022................................. MG5862 5001341-022................................. MG5619 5001341-022................................. NE0308 5001341-022................................. NE0200 5001341-022................................. MG6797 5001341-022................................. JW0230 5001341-022................................. ND5652 5001341-022................................. ND5775 5001341-022................................. JW0251 5001341-022................................. ND5719 5001341-022................................. JW0248 5001341-022................................. ND5785 5001341-022................................. ND5676 5001341-022................................. ND5661 5001341-022................................. JW0265 5001341-022................................. ND5699 5001341-022................................. ND5767 5001341-022................................. JW0259 5001341-022................................. ND5680 5001341-022................................. ND5749 5001341-022................................. JW0235 5001341-022................................. ND5776 5001341-022................................. ND8580 5001341-022................................. MG6039 5001341-022................................. ND9127 5001341-022................................. JW4287 5001341-022................................. JW0262 5001341-022................................. JW0445 5001341-022................................. JW4665 5001341-022................................. MG5901 5001341-022................................. NE0303 5001341-022................................. ND8703 5001341-022................................. JW4574 5001341-022................................. JW4286 5001341-022................................. JW4491 5001341-022................................. JW4630 5001341-022................................. JW4391 5001341-022................................. MG6550 5001341-022................................. MG6776 5001341-022................................. JW4586 5001341-022................................. JW0352 5001341-022................................. JW4261 5001341-022................................. MG6135 5001341-022................................. JW4685 5001341-022................................. MG6772 5001341-022................................. MG6793 5001341-022................................. MG7111 5001341-022................................. ND8618 5001341-022................................. JW0644 5001341-022................................. JW4631 5001341-022................................. JW4651 5001341-022................................. JW0234 5001341-022................................. JW4646 804121...................................... NN9016 804121...................................... VJ3393 804121...................................... PX3694 804121...................................... RK9168 804121...................................... PX5023 804121...................................... VJ3324 804121...................................... VJ3504 804121...................................... NN9115 804121...................................... NN8936 804121...................................... PX3816 804121...................................... VJ3412 804121...................................... RK9163 804121...................................... VJ3447 804121...................................... RK9230 804121...................................... RK9109 804121...................................... PX4627 804121...................................... RK8990 804121...................................... SP9459 804121...................................... RK8656 804121...................................... NN8933 804121...................................... VJ3444 804121...................................... ND5864 804121...................................... NN9020 804121...................................... RK8905 804121...................................... SR1733 804121...................................... NN9047 804121...................................... PX3692 804121...................................... PX3786 804121...................................... NN9025 804121...................................... NN9007 804121...................................... RK9100 804121...................................... VJ3399 804121...................................... PX4970 804121...................................... PX5013
[[Page 9279]]
804121...................................... RK8904 804121...................................... NN8986 804121...................................... NN8829 804121...................................... VJ3459 804121...................................... RK9143 804121...................................... VJ3414 804121...................................... NN9028 804121...................................... SP1557 804121...................................... PX5003 804121...................................... PX5042 804121...................................... VJ3475 804121...................................... ND7330 804121...................................... PX3714 831021-003.................................. NS8913 831021-003.................................. ND6512 831021-003.................................. ND6941 831021-003.................................. ND9576 831021-003.................................. NS7555 831021-003.................................. NS8286 831021-003.................................. NS7447 831021-003.................................. ND6488 831021-003.................................. ND8296 831021-003.................................. ND6956 831021-003.................................. ND7879 831021-003.................................. ND6509 831021-003.................................. ND9814 831021-003.................................. NN7331 831021-003.................................. ND6991 831021-003.................................. ND6894 831021-003.................................. NS6413 831021-003.................................. ND7344 831021-003.................................. ND6947 831021-003.................................. NN8732 831021-003.................................. ND8536 831021-003.................................. ND6946 831021-003.................................. ND6723 831021-003.................................. ND9294 831021-003.................................. ND9290 831021-003.................................. ND6013 831021-003.................................. ND8937 831021-003.................................. NS7160 831021-003.................................. NS6435 831021-003.................................. NS6591 831021-003.................................. ND9558 831021-003.................................. NS8479 831021-003.................................. NS9382 831021-003.................................. ND8965 831021-003.................................. ND9837 831021-003.................................. ND5959 831021-003.................................. NS6491 831021-003.................................. NS9072 831021-003.................................. ND9625 831021-003.................................. ND6714 831021-003.................................. ND6820 831021-003.................................. ND8972 831021-003.................................. NE0286 831021-003.................................. NE0347 831021-003.................................. ND8010 831021-003.................................. ND8956 831021-003.................................. ND9535 831021-003.................................. ND9831 831021-003.................................. NE0227 831021-003.................................. ND8283 831021-003.................................. ND9730 831021-003.................................. NN7656 831021-003.................................. NS7775 831021-003.................................. ND9815 831021-003.................................. ND6135 831021-003.................................. NS8491 831021-003.................................. NS6395 831021-003.................................. NS8584 831021-003.................................. NN7272 831021-003.................................. MG7159 831021-003.................................. NS6592 831021-003.................................. ND7862 831021-003.................................. ND6684 831021-003.................................. NN7744 831021-003.................................. ND7480 831021-003.................................. ND7873 831021-003.................................. ND6827 831021-003.................................. ND6576 831021-003.................................. ND9261 831021-003.................................. NS8686 831021-003.................................. ND9052 831021-003.................................. ND6897 831021-003.................................. ND6565 831021-003.................................. NN8966 831021-003.................................. PX3707 831021-003.................................. NS7031 831021-003.................................. ND6584 831021-003.................................. ND9883 831021-003.................................. NS6535 831021-003.................................. ND7852 831021-003.................................. ND9662 831021-003.................................. ND7871 831021-003.................................. JW0106 831021-003.................................. ND8305 831021-003.................................. NS6409 831021-003.................................. NE0442 831021-003.................................. ND9095 831021-003.................................. ND9302 831021-003.................................. ND9023 831021-003.................................. ND8009 831021-003.................................. ND8477 831021-003.................................. ND7492 831021-003.................................. ND8776 831021-003.................................. ND6524 831021-003.................................. ND6704 831021-003.................................. ND8911 831021-003.................................. ND8789 831021-003.................................. ND8798 831021-003.................................. ND6407 831021-003.................................. ND7668 831021-003.................................. ND9179 831021-003.................................. NE0421 831021-003.................................. ND6513 831021-003.................................. ND6744 831021-003.................................. ND7654 831021-003.................................. ND7870 831021-003.................................. ND9759 831021-003.................................. ND6561 831021-003.................................. ND5826 831021-003.................................. ND6031 831021-003.................................. ND8714 831021-003.................................. ND8872 831021-003.................................. ND6678 831021-003.................................. ND6629 831021-003.................................. ND8995 831021-003.................................. NE0302 831021-003.................................. ND6405 831021-003.................................. NS8300 831021-003.................................. NS8769 831021-003.................................. NS7147 831021-003.................................. ND6649 831021-003.................................. ND7766 831021-003.................................. NS7864 831021-003.................................. NS8734 831021-003.................................. ND6677 831021-003.................................. NS7911 831021-003.................................. ND8205 831021-003.................................. ND8804 831021-003.................................. ND6639 831021-003.................................. ND8994 831021-003.................................. ND7275 831021-003.................................. ND9195 831021-003.................................. ND6178 831021-003.................................. ND8639 831021-003.................................. ND9760 831021-003.................................. ND9108X 831021-003.................................. ND6427 831021-003.................................. ND6590 831021-003.................................. NS6551 831021-003.................................. JW1158 831021-003.................................. ND6412 831021-003.................................. ND7922 831021-003.................................. NS8678 831021-003.................................. ND8930 831021-003.................................. ND6596 831021-003.................................. ND9570 831021-003.................................. NN9027 831021-003.................................. ND6446 831021-003.................................. NE0275 831021-003.................................. ND9917 831021-003.................................. NS7919 831021-003.................................. NS7907 831021-003.................................. ND6583 831021-003.................................. NN7420 831021-003.................................. ND7746 831021-003.................................. ND8187 831021-003.................................. NN8999 831021-003.................................. ND6043 831021-003.................................. ND7880 831021-003.................................. NN7175 831021-003.................................. ND9816 831021-003.................................. ND8174 831021-003.................................. ND6045 831021-003.................................. NS7562 831021-003.................................. JW0075 831021-003.................................. ND6848 831021-003.................................. ND8531 831021-003.................................. ND6311 831021-003.................................. ND8144 831021-003.................................. ND5798 831021-003.................................. ND8113 831021-003.................................. ND9642 831021-003.................................. ND7436 831021-003.................................. ND9054 831021-003.................................. ND9683 831021-003.................................. ND5991 831021-003.................................. ND6026 831021-003.................................. ND6616 831021-003.................................. ND6530 831021-003.................................. NE0374 831021-003.................................. ND6364 831021-003.................................. ND7718 831021-003.................................. ND6473 831021-003.................................. ND6436 831021-003.................................. ND6887 831021-003.................................. ND6518 831021-003.................................. ND6479 831021-003.................................. NS6330 831021-003.................................. ND7264 831021-003.................................. ND8151 831021-003.................................. ND6562 831021-003.................................. NS8776 831021-003.................................. ND6519 831021-003.................................. ND7659 831021-003.................................. NS9049 831021-003.................................. NS6861 831021-003.................................. ND9571 831021-003.................................. ND9346 831021-003.................................. ND6501 831021-003.................................. NS8505
[[Page 9280]]
831021-003.................................. ND9338 831021-003.................................. ND9775 831021-003.................................. ND6485 831021-003.................................. ND7165 831021-003.................................. ND9371 831021-003.................................. ND9537 831021-003.................................. NS7889 831021-003.................................. ND7877 831021-003.................................. ND8670 831021-003.................................. ND9032 831021-003.................................. ND8781 831021-003.................................. ND8604 831021-003.................................. ND9329 831021-003.................................. ND9110 831021-003.................................. ND5997 831021-003.................................. ND6027 831021-003.................................. ND9589 831021-003.................................. ND6575 831021-003.................................. ND6592 831021-003.................................. ND6463 831021-003.................................. NS8583 831021-003.................................. NS8590 831021-003.................................. NS8567 831021-003.................................. NS6795 831021-003.................................. NS7110 831021-003.................................. NS6587 831021-003.................................. NS6404 831021-003.................................. ND6486 5001341-022................................. JW0942 5001341-022................................. ND9231 5001341-022................................. JW4812 5001341-022................................. ND6555 5001341-022................................. M1375 5001341-022................................. MG6627 5001341-022................................. MG6794 5001341-022................................. ND9399 5001341-022................................. NE0084 5001341-022................................. MG6252 5001341-022................................. ND7422 5001341-022................................. ND7043 5001341-022................................. MG5722 5001341-022................................. MG5918 5001341-022................................. ND6984 5001341-022................................. M0839 5001341-022................................. M0922 5001341-022................................. M0938 5001341-022................................. M1117 5001341-022................................. M0307 5001341-022................................. JW3871 5001341-022................................. M1125 5001341-022................................. M1149 5001341-022................................. JW2681 5001341-022................................. M0270 5001341-022................................. M1120 5001341-022................................. M0205 5001341-022................................. AE9352 5001341-022................................. JW3492 5001341-022................................. ND6148 5001341-022................................. ND8907 5001341-022................................. M1235 5001341-022................................. MG5585 5001341-022................................. ND8436 5001341-022................................. MG5696 5001341-022................................. ND8704 5001341-022................................. JW2284 5001341-022................................. JW2313 5001341-022................................. JW2498 5001341-022................................. JW2541 5001341-022................................. JW2560 5001341-022................................. JW2589 5001341-022................................. JW2639 5001341-022................................. JW2760 5001341-022................................. JW2792 5001341-022................................. M0579 5001341-022................................. MG2825 5001341-022................................. MG5477 5001341-022................................. ND5917 5001341-022................................. JW1976 5001341-022................................. JW2653 5001341-022................................. JW2608 5001341-022................................. JW2727 5001341-022................................. JW2764 5001341-022................................. JW2265 5001341-022................................. JW2474 5001341-022................................. JW2396 5001341-022................................. JW3554 5001341-022................................. JW2667 5001341-022................................. MG2302 5001341-022................................. MG3972 5001341-022................................. JW3930 5001341-022................................. ND6749 5001341-022................................. M1172 5001341-022................................. JW2104 5001341-022................................. JW2519 5001341-022................................. JW2640 5001341-022................................. JW2517 5001341-022................................. JW2663 5001341-022................................. JW2823 5001341-022................................. M0536 5001341-022................................. JW2725 5001341-022................................. MG5917 5001341-022................................. JW0681 5001341-022................................. JW0711 5001341-022................................. JW0740 5001341-022................................. JW0807 5001341-022................................. JW1089 5001341-022................................. JW1362 5001341-022................................. JW2065 5001341-022................................. MG2434 5001341-022................................. MG2846 5001341-022................................. JW0806 804121...................................... NN9854 804121...................................... NN9024 804121...................................... NN9032 804121...................................... PX5029 804121...................................... NN9050 804121...................................... NS8242 804121...................................... NS8260 804121...................................... PX4273 804121...................................... PX4378 804121...................................... RL0857 804121...................................... RX8763 804121...................................... NS8331 804121...................................... NN9824 804121...................................... MG6979 804121...................................... MG7023 804121...................................... MG7055 804121...................................... RK8914 804121...................................... RL0023 804121...................................... PX4328 804121...................................... RK9008 804121...................................... TG1506 804121...................................... KK8226 804121...................................... MG2604 804121...................................... NS6691 804121...................................... RK8968 804121...................................... NN9917 804121...................................... RK7824 804121...................................... M1343 804121...................................... NS6559 804121...................................... NS7767 804121...................................... NE0363 804121...................................... PX3771 804121...................................... NN9972 804121...................................... RL0460 804121...................................... RK8310 804121...................................... SR2115 804121...................................... TG2826 804121...................................... PX5018 804121...................................... PX5002 831021-003.................................. ND7627 831021-003.................................. ND6890 831021-003.................................. ND7461 831021-003.................................. ND9616 831021-003.................................. NE0413 831021-003.................................. NS8825 831021-003.................................. NS6350 831021-003.................................. NS7168 831021-003.................................. NS7705 831021-003.................................. NS7848 831021-003.................................. ND9128 831021-003.................................. ND9541 831021-003.................................. ND9671 831021-003.................................. ND9684 831021-003.................................. NE0277 831021-003.................................. NE0384 831021-003.................................. NE0396 831021-003.................................. ND6421 831021-003.................................. ND6599 831021-003.................................. ND6614 831021-003.................................. ND7847 831021-003.................................. ND8346 831021-003.................................. ND8853 831021-003.................................. ND8915 831021-003.................................. NS8719 831021-003.................................. NS8838 831021-003.................................. NT0169 831021-003.................................. NS9584 831021-003.................................. ND6445 831021-003.................................. ND6834 831021-003.................................. ND7467 831021-003.................................. ND8887 831021-003.................................. ND6520 831021-003.................................. NS8611 831021-003.................................. NS7640 831021-003.................................. NN7037 831021-003.................................. NN7590 831021-003.................................. NN8120 831021-003.................................. NN8573 831021-003.................................. NN9719 831021-003.................................. NS8784 831021-003.................................. TB6B367 831021-003.................................. NN9557 831021-003.................................. NN9710 831021-003.................................. NS8374 831021-003.................................. NS8770 831021-003.................................. NS9022 831021-003.................................. NS8416 831021-003.................................. NS6474 831021-003.................................. ND8912 831021-003.................................. NT0108 831021-003.................................. NS8836 831021-003.................................. NN8310 831021-003.................................. NS8559 5001341-022................................. JW4713 5001341-022................................. MG6743 5001341-022................................. ND6924 831021-003.................................. ND9177 831021-003.................................. ND9496 831021-003.................................. NS7894 831021-003.................................. NS8559 831021-003.................................. NS9072 804121...................................... PX3805
[[Page 9281]]
804121...................................... PX4266
For Engines Installed on an Airplane
(1) For engines installed on an airplane with affected 1st stage fan blades installed, perform the actions in paragraphs (f)(3) through (f)(6)(ii) of this AD at the next 1st stage fan blade exposure.
For Engines Not Installed on an Airplane, or, for Affected 1st Stage Fan Blades Not Installed in an Engine
(2) For engines not installed on an airplane with affected 1st stage fan blades installed, or, for affected 1st stage fan blades not installed in an engine, paragraph (h) of this AD applies.
1st Stage Fan Blade Check
(3) Check the 1st stage fan blade for a circled, letter I, on the approved marking area of the outboard side of the blade platform. If the blade has this marking, no further action is required.
(4) Remove 1st stage fan blades without a circled, letter I, on the approved marking area of the outboard side of the blade platform, if installed.
(5) Inspect the 1st stage fan blade root thickness. You can find information on inspecting the blade root thickness in PW Engine Manual Section 72-31-02, Inspect-01, and Repair-23.
(6) For 1st stage fan blades that pass the inspection referenced in paragraph (f)(5) of this AD:
(i) Vibropeen the letter I and a circle around that letter, on the approved marking area of the outboard side of the blade platform. You can find information on approved blade marking in the JT9D-7R4 Engine Manual, Section 72-31-02, Typical Repair-13, Mark Repair Codes.
(ii) Return the 1st stage fan blades to service.
Definition
(g) For the purposes of paragraph (f)(1) of this AD, next 1st stage fan blade exposure is:
(1) When any 1st stage fan blade is removed from the engine; or
(2) When the 1st stage fan hub is removed from the engine.
Prohibited Installation
(h) After the effective date of this AD, do not install any 1st stage fan blades listed in Table 1 of this AD on any airplane, unless the actions of this AD have been done to the 1st stage fan blades.
Alternative Methods of Compliance
(i) 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.
Related Information
(j) None.
Issued in Burlington, Massachusetts, on February 23, 2007. Peter A. White, Acting Manager, Engine and Propeller Directorate, Aircraft Certification Service. [FR Doc. E7-3561 Filed 2-28-07; 8:45 am]
BILLING CODE 4910-13-P
