### 81409 Federal Register / Vol. 75, No. 248 / Tuesday, December 28, 2010 / Rules and Regulations

reduction in the Enterprise portfolios after December 31, 2009. This commenter asks for greater flexibility during times of crisis. FHFA monitors the Enterprises’ portfolios through supervisory and conservatorship channels. If market conditions dictate a need to consider the portfolio reduction provisions in the PSPAs, FHFA will take the appropriate actions to seek amendments to the PSPAs. FHFA thus concludes no change to the interim final rule in this regard is necessary at this
time.

III. Final Rule

FHFA adopts the portfolio holdings criteria established by the PSPAs, as may be amended from time to time, as the standard governing the holding of mortgage assets by the Enterprises. Under the PSPAs, which currently have the same portfolio holdings criteria for both Enterprises, beginning on December 31, 2010, and each year thereafter, each Enterprise is required to reduce its mortgage assets to 90 percent of the maximum allowable amount it was permitted to hold as of December 31 of the immediately preceding calendar year, until the maximum amount of the mortgage assets owned by each Enterprise reaches $250 billion. Thus, the maximum allowable amount of mortgage assets that each Enterprise may own as of December 31, 2010, is $810 billion.

This regulation will remain in effect until amended or the Enterprises are no longer subject to the PSPAs. Amendments to the portfolio limits and criteria on the limits can be made by amendment of the PSPAs. Under the final regulation, the Enterprises are to comply with the PSPA portfolio limits as amended from time to time.

While the final regulatory criteria incorporate the PSPAs’ portfolio limits as agreed upon by the Treasury and FHFA as conservator, the Safety and Soundness Act provides that the Director monitor the portfolio of each Enterprise and authorizes the Director to order an Enterprise to dispose of or acquire any asset under terms and conditions to be determined by the Director, if the Director determines that such action is consistent with the purposes of the Safety and Soundness Act or the authorizing statute of the Enterprise. 12 U.S.C. 4624(c).
IV. Section by Section Analysis

Section 1252.1

Section 1252.1 adopts the portfolio holdings criteria established by the PSPAs, as they may be amended from time to time, as the standard for this rule.

Under the current PSPAs, which have the same portfolio holdings criteria for both Enterprises, an Enterprise may hold mortgage assets up to $900 billion as of December 31, 2009. Starting on December 31, 2010, the Enterprise portfolio limits will decrease annually by 10 percent from the maximum limit in the preceding year until the limit reaches a level of $250 billion, at which point, no further decrease is currently required. Adjustments could be made to those criteria by amendment of the
PSPAs.

Compliance with the PSPAs is necessary to ensure that each Enterprise receives adequate capital to support its ongoing business operations. FHFA’s goals for the conservatorship include strengthening Enterprise capacity to support the secondary mortgage market. The criteria for Enterprise portfolio holdings established in the PSPAs provided the Enterprises capacity to provide stability and liquidity to the secondary mortgage market (including the purchase of delinquent mortgages), while mitigating systemic risk, and facilitating Enterprise efforts to achieve a balance between their mission and safe and sound operations in the intermediate term. The retained portfolio reduction provided for in the PSPAs avoids the need for potentially destabilizing liquidation in the near term, while ensuring that in the future the potential for systemic risk associated with these portfolios is reduced.

FHFA’s establishment of PSPA portfolio criteria as its regulatory criteria represents an exercise of authority consistent with the authority granted by Congress under section 1369E of the Safety and Soundness Act.

Section 1252.2

Section 1252.2 addresses the effective duration of the interim rule. FHFA expects these regulations to be effective until any amendment or until the Enterprises are no longer subject to the terms and obligations of the PSPAs.
V. Paperwork Reduction Act

The regulation does not contain any collections of information pursuant to the Paperwork reduction Act of 1995 (44
U.S.C. 3501 et seq. ). Therefore, FHFA has not submitted any information to the Office of Management and Budget for review.
VI. Regulatory Flexibility Act

The regulation applies only to the Enterprises, which do not come within the meaning of small entities as defined in the Regulatory Flexibility Act (RFA). See 5 U.S.C. 601(6). Therefore, in accordance with section 605(b) of the RFA, 5 U.S.C. 605(b), FHFA, hereby, certifies that the regulation will not have a significant economic impact on a substantial number of small entities.
List of Subjects in 12 CFR Part 1252

Government-sponsored enterprises, Mortgages, Portfolio holdings.

**PART 1252—PORTFOLIO HOLDINGS**

Authority and Issuance

■ Therefore, the Federal Housing Finance Agency hereby adopts the interim final rule, published at 74 FR 5609 (January 30, 2009) as final without change.

Dated: December 17, 2010. Edward J. DeMarco, Acting Director, Federal Housing Finance Agency.

[FR Doc. 2010–32531 Filed 12–27–10; 8:45 am]

**BILLING CODE 8070–01–P**

**DEPARTMENT OF TRANSPORTATION**

**Federal Aviation Administration**

**14 CFR Part 39**

**[Docket No. FAA–2010–0437; Directorate Identifier 2009–NM–130–AD; Amendment**  **39–16539; AD 2010–25–06]**

**RIN 2120–AA64**

**Airworthiness Directives; The Boeing Company Model 737–200, –300, –400,**  **and –500 Series Airplanes**

**AGENCY :**  Federal Aviation Administration (FAA), DOT.

**ACTION :**  Final rule.

**SUMMARY :**  We are adopting a new airworthiness directive (AD) for certain Model 737–200, –300, –400, and –500 series airplanes. This AD requires repetitive inspections for cracking of certain fuselage frames and stub beams, and corrective actions if necessary. This AD also provides for an optional repair, which would terminate the repetitive inspections. For airplanes on which a certain repair is done, this AD also requires repetitive inspections for cracking of certain fuselage frames and stub beams, and corrective actions if necessary. This AD results from reports of the detection of fatigue cracks at certain frame sections, in addition to stub beam cracking, caused by high flight cycle stresses from both pressurization and maneuver loads. We are issuing this AD to detect and correct fatigue cracking of certain fuselage frames and stub beams and possible


### 81410 Federal Register / Vol. 75, No. 248 / Tuesday, December 28, 2010 / Rules and Regulations

severed frames, which could result in reduced structural integrity of the frames. This reduced structural integrity can increase loading in the fuselage skin, which will accelerate skin crack growth and could result in rapid decompression of the fuselage.

**DATES :**  This AD is effective February 1,

2011.

The Director of the Federal Register approved the incorporation by reference of a certain publication listed in the AD as of February 1, 2011.

**ADDRESSES :**  For service information identified in this AD, contact Boeing Commercial Airplanes, Attention: Data & Services Management, P. O. Box 3707, MC 2H–65, Seattle, Washington 98124– 2207; telephone 206–544–5000, extension 1; fax 206–766–5680; e-mail me.boecom@boeing.com; Internet https://www.myboeingfleet.com.
Examining the AD Docket

You may examine the AD docket on the Internet at http:// www.regulations.gov; or in person at the Docket Management Facility between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The AD docket contains this AD, the regulatory evaluation, any comments received, and other information. The address for the Docket Office (telephone 800–647–5527) is the Document Management Facility, U.S. Department of Transportation, Docket Operations, M–30, West Building Ground Floor, Room W12–140, 1200 New Jersey Avenue, SE., Washington, DC 20590.

**FOR FURTHER INFORMATION CONTACT :**  Wayne Lockett, Aerospace Engineer, Airframe Branch, ANM–120S, FAA, Seattle Aircraft Certification Office, 1601 Lind Avenue, SW., Renton, Washington 98057–3356; telephone (425) 917–6447; fax (425) 917–6590.

**SUPPLEMENTARY INFORMATION :** 

Discussion

We issued a notice of proposed rulemaking (NPRM) to amend 14 CFR part 39 to include an airworthiness directive (AD) that would apply to certain Model 737–200, –300, –400, and –500 series airplanes. That NPRM was published in the Federal Register on May 7, 2010 (75 FR 25124). That NPRM proposed to require repetitive inspections for cracking of certain fuselage frames and stub beams, and corrective actions if necessary. That NPRM also proposed an optional repair, which would terminate the repetitive inspections. For airplanes on which a certain repair is done, that NPRM also proposed to require repetitive inspections for cracking of certain fuselage frames and stub beams, and corrective actions if necessary.

Comments

We gave the public the opportunity to participate in developing this AD. We considered the comments received.
Request To Change Paragraph (i)

Boeing asked that paragraph (i) of the NPRM be changed to include a high frequency eddy current (HFEC) inspection. Boeing stated that Boeing Alert Service Bulletin 737–53A1254, Revision 1, dated July 9, 2009, provides two options for inspections: detailed and HFEC. Boeing added that for areas where the repair hinders the inspection, both detailed and HFEC inspection options were provided, depending on which option was chosen for the original inspection.

We agree with the commenter for the reasons provided. We have changed paragraph (i) of this AD to include an option for the HFEC inspection.
Request To Change Compliance Time

Boeing also asked that the compliance time specified in paragraph (g)(3) of the NPRM be changed to ‘‘ the sooner of (i) within 4,500 flight cycles after the effective date of the AD or (ii) within 9,000 flight cycles after the previous inspection done in accordance with Boeing Alert Service Bulletin 737– 53A1254, dated February 17, 2005. ’’ Boeing stated that new data indicate that the repeat interval for the area below the floor should be changed to 9,000 flight cycles from 4,500 flight cycles. Boeing added that for airplanes on which the inspection in the original issue of Boeing Alert Service Bulletin 737–53A1254 has been done, the compliance time as written in Boeing Alert Service Bulletin 737–53A1254, Revision 1 ( i.e., 3,000 flight cycles from release of Revision 1 or 4,500 flight cycles from previous inspection, whichever is sooner), could cause a significant impact by putting some airplanes out of compliance. Boeing noted that the NPRM could potentially allow a longer compliance time than that in the original issue of the service bulletin. Boeing recommends that paragraph (g)(3) be changed as specified previously.

We acknowledge the commenter’s concern and provide the following. The compliance times required by paragraph (g) are at the ‘‘ later of, ’’ not the ‘‘ sooner of, ’’ the compliance times specified in paragraphs (g)(3)(i) and (g)(3)(ii). We agree that the compliance times specified in paragraphs (g)(3)(i) and (g)(3)(ii) of this AD are somewhat confusing and can be clarified. Therefore, we have combined paragraphs (g)(3)(i) and (g)(3)(ii) with paragraph (g)(3) to provide that clarification.

Request To Change Initial Inspection Threshold

Southwest Airlines asked that the initial inspection threshold required by paragraphs (g)(1) and (g)(2) of the NPRM be changed. Southwest stated that the specified threshold will pose a significant burden on its airline to complete the inspections within the required timeframe. Southwest projected that half of its Model 737–300and –500 fleet will require an out-ofsequence maintenance visit to support this inspection threshold. Southwest added that this is based on its current substantial maintenance schedule, fleet utilization, and the proposed compliance thresholds based on each airplane’s total flight cycles.

We do not agree with the commenter’s request. No supporting data were submitted proposing alternative inspection thresholds to maintain an adequate level of safety for its fleet. However, under the provisions of paragraph (m) of this AD, we will consider requests for approval of an alternative inspection threshold if sufficient data are submitted to substantiate that changing the initial inspection threshold would provide an acceptable level of safety. We have not changed the AD in this regard.

Conclusion

We reviewed the relevant data, considered the comments received, and determined that air safety and the public interest require adopting the AD with the changes described previously. We also determined that these changes will not increase the economic burden on any operator or increase the scope of the AD.

Costs of Compliance

We estimate that this AD affects 635 airplanes of U.S. registry. The following table provides the estimated costs for U.S. operators to comply with this AD.


### 81411 Federal Register / Vol. 75, No. 248 / Tuesday, December 28, 2010 / Rules and Regulations

TABLE

### —E STIMATED 

### C OSTS

Action Work hours Average labor rate per hour Cost per product Number of U.S.- registered airplanes Fleet cost

BS 616 and BS 639 inspection/lower frame

and stub beam. 15 $85 $1,275 per inspection cycle 635 $809,625 per inspection cycle.

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

This AD will not have federalism implications under Executive Order 13132. This AD 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.

For the reasons discussed above, I certify that this AD:

(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.

You can find our regulatory evaluation and the estimated costs of compliance in the AD Docket.
List of Subjects in 14 CFR Part 39

Air transportation, Aircraft, Aviation safety, Incorporation by reference, Safety. Adoption of the Amendment

■ Accordingly, under the authority delegated to me by the Administrator, the FAA amends 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.

**§ 39.13 [Amended]**

■ 2. The FAA amends § 39.13 by adding the following new AD: 2010–25–06 The Boeing Company: Amendment 39–16539. Docket No. FAA– 2010–0437; Directorate Identifier 2009–NM–
130–AD.

Effective Date

(a) This airworthiness directive (AD) is effective February 1, 2011.

Affected ADs

(b) None.

Applicability

(c) This AD applies to The Boeing Company Model 737–200, –300, –400, and –500 series airplanes, certificated in any category; as identified in Boeing Alert Service Bulletin 737–53A1254, Revision 1, dated July 9, 2009.

Subject

(d) Air Transport Association (ATA) of America Code 53: Fuselage.

Unsafe Condition

(e) This AD results from the detection of fatigue cracks at certain frame sections, in addition to stub beam cracking, caused by high flight cycle stresses from both pressurization and maneuver loads. The Federal Aviation Administration is issuing this AD to detect and correct fatigue cracking of certain fuselage frames and stub beams and possible severed frames, which could result in reduced structural integrity of the frames. This reduced structural integrity can increase loading in the fuselage skin, which will accelerate skin crack growth and could result in rapid decompression of the fuselage.

Compliance

(f) You are responsible for having the actions required by this AD performed within the compliance times specified, unless the actions have already been done. Repetitive Inspections and Corrective
Actions

(g) At the applicable time specified in paragraph (g)(1), (g)(2), or (g)(3) of this AD: Do a detailed or high frequency eddy current (HFEC) inspection for cracking of body station (BS) 616 and BS 639 frame webs, inner chord, and outer chord, and the stub beams; and do all applicable related investigative and corrective actions; by accomplishing all the actions specified in Part 1 of the Accomplishment Instructions of Boeing Alert Service Bulletin 737–53A1254, Revision 1, dated July 9, 2009, except as specified in paragraphs (i) and (j) of this AD. Do all applicable related investigative and corrective actions before further flight. Thereafter, repeat the inspection at intervals not to exceed 4,500 flight cycles since accomplishing the detailed inspection or at intervals not to exceed 9,000 flight cycles since accomplishing the HFEC inspection, as applicable.

(1) For airplanes on which no inspection of the BS 616 and BS 639 frames specified in Boeing Alert Service Bulletin 737– 53A1254, dated February 17, 2005, has been done as of the effective date of this AD, and that have accumulated fewer than 55,000 total flight cycles as of the effective date of this AD: Inspect within 3,000 flight cycles after the effective date of this AD, or before the accumulation of 56,500 total flight cycles, whichever occurs first.

(2) For airplanes on which no inspection of the BS 616 and BS 639 frames specified in Boeing Alert Service Bulletin 737– 53A1254, dated February 17, 2005, has been done as of the effective date of this AD, and that have accumulated 55,000 or more total flight cycles as of the effective date of this AD: Inspect within 1,500 flight cycles after the effective date of this AD.

(3) For airplanes on which a detailed or HFEC inspection of the BS 616 and BS 639 frames, specified in Boeing Alert Service Bulletin 737–53A1254, dated February 17, 2005, has been done as of the effective date of this AD: Inspect within 4,500 flight cycles after the previous inspection done in accordance with Boeing Alert Service Bulletin 737–53A1254, dated February 17, 2005, or within 3,000 flight cycles after the effective date of this AD, whichever occurs later.

Post-Repair Repetitive Inspections and
Corrective Actions

(h) For airplanes on which the repair specified in Part 4 of the Accomplishment Instructions of Boeing Alert Service Bulletin 737–53A1254, Revision 1, dated July 9, 2009, has been done: At the applicable time specified in paragraphs (h)(1) and (h)(2) of this AD, do a detailed or HFEC inspection for


### 81412 Federal Register / Vol. 75, No. 248 / Tuesday, December 28, 2010 / Rules and Regulations

cracking of the replacement frame section (frame webs, inner chord, and outer chord); and do all applicable related investigative and corrective actions; by accomplishing all the actions specified in Part 1 of the Accomplishment Instructions of Boeing Alert Service Bulletin 737–53A1254, Revision 1, dated July 9, 2009, except as specified in paragraphs (i) and (j) of this AD. Do all applicable related investigative and corrective actions before further flight. Thereafter, repeat the inspection at intervals not to exceed 4,500 flight cycles since accomplishing the detailed inspection or at intervals not to exceed 9,000 flight cycles since accomplishing the HFEC inspection, as applicable.

(1) For airplanes on which a partial frame splice repair at BS 616 or BS 639 has been done, and the inner chord and web have been cold-worked: Inspect within 44,000 flight cycles after the repair has been done.

(2) For airplanes on which a partial frame splice repair at BS 616 or BS 639 has been done, and the inner chord and web have not been cold-worked: Inspect within 29,000 flight cycles after that repair has been done.

Alternative Inspection of Repaired or Modified Area

(i) For airplanes on which a repair or preventative modification exists on the inner chord below the floor which prevents the accomplishment of the detailed or HFEC inspection in that area as required by paragraph (g) of this AD: In lieu of inspecting that area, do a detailed or HFEC inspection of the inner chord along the length of the repair and around the fastener heads in accordance with Part 1 of the Accomplishment Instructions of Boeing Alert Service Bulletin 737–53A1254, Revision 1, dated July 9, 2009.

Exceptions to Service Information

(j) Where Boeing Alert Service Bulletin 737–53A1254, Revision 1, dated July 9, 2009, specifies to contact Boeing for repair instructions and repair: Before further flight, repair the cracking using a method approved in accordance with the procedures specified in paragraph (m) of this AD.

(k) Although Boeing Alert Service Bulletin 737–53A1254, Revision 1, dated July 9, 2009, specifies to submit information to the manufacturer, this AD does not include that requirement.

Terminating Action

(l) Doing the repair specified in Part 4 of Boeing Alert Service Bulletin 737–53A1254, Revision 1, dated July 9, 2009, terminates the repetitive inspection requirements of paragraph (g) of this AD for the repaired frame only.

Alternative Methods of Compliance (AMOCs)

(m)(1) The Manager, Seattle Aircraft Certification Office (ACO), FAA, has the authority to approve AMOCs for this AD, if requested using the procedures found in 14 CFR 39.19. Send information to ATTN: Wayne Lockett, Aerospace Engineer, Airframe Branch, ANM–120S, FAA, Seattle Aircraft Certification Office, 1601 Lind Avenue, SW., Renton, Washington 98057– 3356; telephone (425) 917–6447; fax (425) 917–6590. Or, e-mail information to 9–ANM– Seattle-ACO-AMOC-Requests@faa.gov.

(2) To request a different method of compliance or a different compliance time for this AD, follow the procedures in 14 CFR 39.19. Before using any approved AMOC on any airplane to which the AMOC applies, notify your principal maintenance inspector (PMI) or principal avionics inspector (PAI), as appropriate, or lacking a principal inspector, your local Flight Standards District Office. The AMOC approval letter must specifically reference this AD.

(3) An AMOC that provides an acceptable level of safety may be used for any repair required by this AD, if it is approved by an Authorized Representative for the Boeing Commercial Airplanes Organization Designation Authorization (ODA) that has been authorized by the Manager, Seattle ACO, to make those findings. For a repair method to be approved, the repair must meet the certification basis of the airplane.

Material Incorporated by Reference

(n) You must use Boeing Alert Service Bulletin 737–53A1254, Revision 1, dated July 9, 2009, to do the actions required by this AD, unless the AD specifies otherwise.

(1) The Director of the Federal Register approved the incorporation by reference of
this service information under 5 U.S.C. 552(a) and 1 CFR part 51.

(2) For service information identified in this AD, contact Boeing Commercial Airplanes, Attention: Data & Services Management, P. O. Box 3707, MC 2H–65, Seattle, Washington 98124–2207; telephone 206–544–5000, extension 1; fax 206–766– 5680; e-mail me.boecom@boeing.com;

Internet https://www.myboeingfleet.com.

(3) You may review copies of the service information at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington. For information on the availability of this material at the FAA, call

425–227–1221.

(4) You may also review copies of the service information that is incorporated by
reference at the National Archives and Records Administration (NARA). For information on the availability of this material at NARA, call 202–741–6030, or go

to: http://www.archives.gov/federal

_register/
code

_ of

_ federal

_regulations/
ibr

_locations.html.

Issued in Renton, Washington on December 16, 2010.
Ali Bahrami, Manager, Transport Airplane Directorate, Aircraft Certification Service.

[FR Doc. 2010–32354 Filed 12–27–10; 8:45 am]

**BILLING CODE 4910–13–P DEPARTMENT OF TRANSPORTATION** 

**Federal Aviation Administration**

**14 CFR Part 39**

**[Docket No. FAA–2009–0913; Directorate Identifier 2009–NM–101–AD; Amendment**  **39–16545; AD 2010–26–06]**

**RIN 2120–AA64**

**Airworthiness Directives; The Boeing Company Model 737–600, –700, –700C,**  **–800, and –900 Series Airplanes**

**AGENCY :**  Federal Aviation Administration (FAA), DOT.

**ACTION :**  Final rule.

**SUMMARY :**  We are adopting a new airworthiness directive (AD) for certain Model 737–600, –700, –700C, –800, and –900 series airplanes. This AD requires inspections for scribe lines in the fuselage skin at lap joints, the splice strap at certain butt joints, the skin or doubler at certain approved repair doublers, and the skin at decal locations; and related investigative and corrective actions if necessary. This AD results from reports of scribe line damage found adjacent to the skin lap joints, decals, and wing-to-body fairings. We are issuing this AD to detect and correct scribe lines, which can develop into fatigue cracks in the skin. Undetected fatigue cracks can grow and cause sudden decompression of the airplane.

**DATES :**  This AD is effective February 1,

2011.

The Director of the Federal Register approved the incorporation by reference of a certain publication listed in the AD as of February 1, 2011.

**ADDRESSES :**  For service information identified in this AD, contact Boeing Commercial Airplanes, Attention: Data & Services Management, P.O. Box 3707, MC 2H–65, Seattle, Washington 98124– 2207; telephone 206–544–5000, extension 1; fax 206–766–5680; e-mail me.boecom@boeing.com; Internet https://www.myboeingfleet.com.

You may examine the AD docket on the Internet at http://www.regulations.

gov; or in person at the Docket Management Facility between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The AD docket contains this AD, the regulatory evaluation, any comments received, and other information. The address for the Docket Office (telephone 800–647–5527) is the Document Management Facility, U.S. Department of Transportation, Docket Operations, M–30, West Building Ground Floor, Room W12–140,