preamble attached >>>
ADs updated daily at www.Tdata.com
2009-24-11 GENERAL ELECTRIC COMPANY:
( c o r r e c t i o n )
Amendment 39-16103. Docket No. FAA-2009-0328; Directorate Identifier 2008-NE-44-AD. 

TDATA NOTE: The FAA is delaying the effective date by  30  days  to  allow
            sufficient time to make corrections to  the  compliance  text.
            This copy reflects the change from January 4 to February 3.

EFFECTIVE DATE

(a) This airworthiness directive (AD) becomes effective February 3, 2010.

AFFECTED ADS

(b) None.

APPLICABILITY

(c) This  AD applies  to General  Electric Company  (GE) CF34-1A, CF34-3A,
    CF34-3A1,  CF34-3A2,  CF34-3B, and  CF34-3B1  turbofan engines.  These
    engines  are installed  on, but  not limited  to, Bombardier  Canadair
    Models CL-600-2A12, CL-600-2B16, and CL-600-2B19 airplanes.

UNSAFE CONDITION

(d) This AD results from a report  of an under-cowl fire and a failed  fan
    blade.  We are  issuing this  AD to  prevent failure  of certain  part
    number (P/N) and serial number  (SN) fan blades and aft  actuator head
    hoses, which could result in an under-cowl fire and subsequent  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.

CF34-3A1 AND CF34-3B1 ENGINES

(f) For  CF34-3A1  engines  with fan  drive  shaft,  P/N  6036T78P02,  and
    airworthiness limitation section life limit of 22,000 CSN; and

(g) For  CF34-3A1  engines  with fan  drive  shaft,  P/N  6036T78P02,  and
    airworthiness limitation section life limit of 15,000 CSN that are  in
    compliance with GE Aircraft Engines (GEAE) Service Bulletin (SB)  CF34
    -AL S/B 72-0147,  dated May 21,  2003, Revision 01,  dated October 17,
    2003, Revision 02, dated  August 5, 2004, or Revision 3,  dated August
    28, 2003; and

(h) For CF34-3B1 engines with  fan blades, P/Ns 6018T30P14 or  4923T56G08,
    that have a fan blade SN listed  in Appendix A of GEAE SB CF34-AL  S/B
    72-0245, Revision 01, dated July 30, 2008;

(i) Do  the following  for the  engines meeting  the criteria in paragraph
    (f), (g), or (h) of this AD, as applicable:

(1) Remove fan blades  from  service within 4,000 cycles-in-service  (CIS)
    after the effective date of this AD or by December 31, 2010, whichever
    occurs first.

INITIAL VISUAL INSPECTION OF THE FAN BLADE ABRADABLE RUB STRIP FOR WEAR

(2) For fan  blades  with  1,200  or  more cycles-since-new  (CSN) on  the
    effective date of this AD, perform an initial visual inspection of the
    fan  blade  abradable rub  strip  for wear  within  20 CIS  after  the
    effective date of this AD.  Use paragraphs 3.A.(1) through 3.A.(2)  of
    the  Accomplishment  Instructions  of  GEAE  SB  CF34-AL  S/B 72-0250,
    Revision 01, dated November 26, 2008, to perform the inspection.

(3) For fan blades with fewer than 1,200 CSN on the effective date of this
    AD, perform an  initial visual inspection  of the fan  blade abradable
    rub strip for  wear within 1,220  CSN. Use paragraphs  3.A.(1) through
    3.A.(2) of the Accomplishment Instructions  of GEAE SB CF34-AL S/B  72
    -0250,  Revision  01,  dated   November  26,  2008,  to   perform  the
    inspection.

(4) If  you find  a continuous  360 degree  rub indication, before further
    flight, visually  inspect the  fan blades  using paragraphs 3.A.(2)(a)
    through 3.A.(2)(b) of the Accomplishment Instructions of GEAE SB  CF34
    -AL S/B 72-0250, Revision 01, dated November 26, 2008.

(5) If  you find  a crack  in the  retaining pin  holes of  the fan blade,
    remove the blade from service.

REPETITIVE VISUAL INSPECTION OF THE FAN BLADE ABRADABLE RUB STRIP FOR WEAR

(6) Within  75  cycles-since-last  inspection  (CSLI)  or  100 hours-since
    -last-inspection  (HSLI),  whichever occurs  later,  perform a  visual
    inspection  of  the  fan  blade  abradable  rub  strip  for  wear. Use
    paragraphs 3.A.(1) through 3.A.(2) of the Accomplishment  Instructions
    of GEAE SB CF34-AL S/B 72-0250, Revision 01, dated  November 26, 2008,
    to perform the inspection.

(i) If  you find  a continuous  360 degree  rub indication, before further
    flight, visually  inspect the  fan blades  using paragraphs 3.A.(2)(a)
    through 3.A.(2)(b) of the Accomplishment Instructions of GEAE SB  CF34
    -AL S/B 72-0250, Revision 01, dated November 26, 2008.

(ii) If  you find  a crack  in the  retaining pin  holes of the fan blade,
     remove the blade from service.

INSPECTION OF THE AFT ACTUATOR HEAD HOSE FITTING ON CF34-3A1 AND CF34- 3B1
ENGINES

(7) Within  750 hours  time-in-service (TIS)  after the  effective date of
    this  AD,  visually  inspect and,  if  necessary,  reposition the  aft
    actuator head hose  fitting. Use paragraph  3.A of the  Accomplishment
    Instructions  of  GEAE  SB  CF34-AL  S/B 73-0046,  Revision  02, dated
    August 27, 2008, to perform the inspection.

CF34-1A, CF34-3A, CF34-3A2, CF34-3B, AND CF34-3A1 ENGINES

(j) For  CF34-3A1  engines  with fan  drive  shaft,  P/N  6036T78P02,  and
    airworthiness limitation section  life limit of  15,000 CSN, that  are
    not in  compliance with  GEAE SB  CF34-AL S/B  72-0147, dated  May 21,
    2003, Revision 01, dated October  17, 2003, Revision 02, dated  August
    5, 2004, or Revision 3, dated August 28, 2003; and

(k) For CF34-1A, CF34-3A, CF34-3A2,  and CF34-3B engines with fan  blades,
    P/N 6018T30P14 or P/N 4923T56G08,  that have a fan blade SN listed  in
    Appendix A of GEAE SB CF34-BJ S/B 72-0229, Revision 01, dated July 30,
    2008;

(l) Do the following for the engines meeting the criteria in paragraph (j)
    or (k) of this AD as applicable:

(1) Remove fan blades, P/N 6018T30P14, from service within 2,400 CSN.

(2) Remove fan blades, P/N 4923T56G08, from service within 1,200 CIS since
    the bushing repair of the fan blade hole.

INITIAL EDDY CURRENT INSPECTION OF THE FAN BLADES

(3) For fan  blades, P/N 6018T30P14,  with more than  850 CSN, perform  an
    initial eddy  current inspection  (ECI) of  the fan  blades for cracks
    within 350  CIS after  the effective  date of  this AD. Use paragraphs
    3.A. or 3.B. of the Accomplishment Instructions of GEAE SB CF34-BJ S/B
    72-0229, Revision 01, dated July 30, 2008, to perform the inspection.

(4) For fan blades, P/N 6018T30P14, with 850 or fewer CSN on the effective
    date of this AD, perform an  initial ECI of the fan blades  for cracks
    within 1,200 CSN.  Use paragraphs 3.A.  or 3.B. of  the Accomplishment
    Instructions of GEAE SB CF34-BJ  S/B 72-0229, Revision 01, dated  July
    30, 2008, to perform the inspection.

(5) If  you find  a crack  in the  retaining pin  holes of  the fan blade,
    remove the blade from service.

REPETITIVE ECI OF THE FAN BLADES

(6) For fan blades, P/N 6018T30P14, within 600 CSLI, perform an ECI of the
    fan  blades  for   cracks.  Use  paragraphs   3.A.  or  3.B.   of  the
    Accomplishment Instructions of GEAE  SB CF34-BJ S/B 72-0229,  Revision
    01, dated July 30, 2008, to perform the inspection.

(7) If  you find  a crack  in the  retaining pin  holes of  the fan blade,
    remove the blade from service.

INITIAL VISUAL INSPECTION OF THE FAN BLADE ABRADABLE RUB STRIP FOR WEAR

(8) For engines with fan blades, P/N 6018T30P14, installed that have a fan
    blade SN listed in Appendix A of GEAE SB CF34-BJ S/B 72-0229, Revision
    01, dated July 30, 2008, with 1,200 or more CSN on the effective  date
    of this AD, and that haven't had an ECI of the fan blades for  cracks,
    do the following:

(i) Perform an initial inspection of the fan blade abradable rub strip for
    wear within 20 CIS after the effective date of this AD. Use  paragraph
    3.A.(1) of the Accomplishment Instructions  of GEAE SB CF34-BJ S/B  72
    -0231,  Revision  02,  dated   November  26,  2008,  to   perform  the
    inspection.

(ii) If you  find a continuous  360 degree rub  indication, before further
     flight, perform a visual inspection of the fan blades for cracks. Use
     paragraphs 3.A(2)(a) or 3.A(2)(b) of the Accomplishment  Instructions
     of GEAE SB CF34-BJ S/B 72-0231, Revision 02, dated November 26, 2008,
     to perform the inspection.

(iii) If you  find a crack  in the retaining  pin holes of  the fan blade,
      remove the blade from service.

REPETITIVE INSPECTION OF THE FAN BLADE ABRADABLE RUB STRIP FOR WEAR

(9) For engines  with fan blades,  P/N 6018T30P14, installed,  if you have
    performed an ECI of the fan  blade, you don't need to inspect  the fan
    blade abradable rub strip for wear.

(10) For  engines with  fan blades,  P/N 6018T30P14,  installed, within 75
    CSLI or 100 HSLI, whichever occurs later, do the following:

(i) Perform a visual inspection of  the fan blade abradable rub strip  for
    wear. Use paragraph 3.A.(1) of the Accomplishment Instructions of GEAE
    SB  CF34-BJ S/B  72-0231, Revision  02,  dated  November 26, 2008,  to
    perform the inspection.

(ii) If you  find a continuous  360 degree rub  indication, before further
     flight, visually inspect the  fan blades using paragraphs  3.A.(2)(a)
     through  3.A.(2)(b) of  the Accomplishment  Instructions  of  GEAE SB
     CF34-BJ S/B 72-0231, Revision 02, dated November 26, 2008.

(iii) If you  find a crack  in the retaining  pin holes of  the fan blade,
      remove the blade from service.

INSPECTION OF THE AFT ACTUATOR HEAD HOSE FITTING ON CF34-3A1 AND CF34-  3B
ENGINES

(11) For CF34-3A1 engines, within  300 hours TIS after the  effective date
     of this AD,  visually inspect and,  if necessary, reposition  the aft
     actuator head hose fitting. Use paragraph 3.A  of the  Accomplishment
     Instructions  of  GEAE SB  CF34-BJ  S/B 73-0062,  Revision  02, dated
     August 27, 2008, to perform the inspection.

(12) For CF34-3B engines, within 400 hours TIS after the effective date of
     this  AD,  visually inspect  and,  if necessary,  reposition  the aft
     actuator head hose fitting.  Use paragraph 3.A of  the Accomplishment
     Instructions  of GEAE   SB CF34-BJ  S/B 73-0062,  Revision 02,  dated
     August 27, 2008, to perform the inspection.

CREDIT FOR PREVIOUS ACTIONS

(m) Inspections previously performed using the following GEAE SBs meet the
    requirements specified in the indicated paragraphs:

(1) CF34-AL  S/B 72-0250,  dated August  15, 2008,  meet the  requirements
    specified in paragraphs (i)(2) through (i)(4) of this AD.

(2) CF34-AL S/B  73-0046, Revision  01,  dated  July 1, 2008,  or  earlier
    issue, meet the requirements specified in paragraph (i)(7) of this AD.

(3) CF34-BJ S/B  72-0229,  dated  April 10, 2008,  meet  the  requirements
    specified in paragraphs (l)(3) and (l)(4) of this AD.

(4) CF34-BJ S/B  72-0231, Revision 01,  dated October 1, 2008,  or earlier
    issue, meet  the requirements  specified in  paragraphs (l)(10)(i) and
    (l)(10)(ii) of this AD.

(5) CF34-BJ S/B  73-0062, Revision  01,  dated  July 1, 2008,  or  earlier
    issue,  meet  the  requirements specified  in  paragraphs  (l)(11) and
    (l)(12) of this AD.

INSTALLATION PROHIBITIONS

(n) After the effective date of this AD:

(1) Do not install any fan  blade into any CF34-3A1 engine with  fan drive
    shaft, P/N 6036T78P02, with  an airworthiness limitation section  life
    limit of 22,000 CSN if that fan blade:

(i) Was  installed  in  a  CF34-3A1  engine  with  fan  drive  shaft,  P/N
    6036T78P02, with  an airworthiness  limitation section  life limit  of
    15,000 CSN; and

(ii) Is listed in Appendix A of GEAE SB CF34-BJ S/B 72-0229, Revision  01,
     dated July 30, 2008; or

(iii) Is listed in Appendix A of GEAE SB CF34-BJ S/B 72-0230, Revision 01,
      dated July 30, 2008.

(2) Do not install any fan  blade into any CF34-3A1 engine with  fan drive
    shaft, P/N 6036T78P02, with  an airworthiness limitation section  life
    limit of 15,000 CSN if that fan blade:

(i) Was  installed in  any  CF34-3A1 engine  with  fan  drive  shaft,  P/N
    6036T78P02, with  an airworthiness  limitation section  life limit  of
    22,000 CSN and,

(ii) Is listed in Appendix A of GEAE SB CF34-AL S/B 72-0245, Revision  01,
     dated July 3, 2008.

ALTERNATIVE METHODS OF COMPLIANCE

(o) 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

(p) Contact John Frost,  Aerospace Engineer, Engine Certification  Office,
    FAA, Engine &  Propeller Directorate, 12  New England Executive  Park,
    Burlington, MA  01803; e-mail: john.frost@faa.gov; telephone (781) 238
    -7756; fax (781) 238-7199, for more information about this AD.

MATERIAL INCORPORATED BY REFERENCE

(q) You must use the GE Aircraft Engines service information specified  in
    the following Table 1 to do the actions required by this AD.

                 TABLE 1--MATERIAL INCORPORATED BY REFERENCE
    ______________________________________________________________________
    SERVICE BULLETIN NO.          PAGE       REVISION        DATE
    ______________________________________________________________________
    CF34-AL S/B 73-0046           All           02       August 27, 2008
    Total Pages: 8

    CF34-BJ S/B 73-0062           All           02       August 27, 2008
    Total Pages: 8

    CF34-BJ S/B 72-0229           All           01       July 30, 2008
    Total Pages: 158

    CF34-BJ S/B 72-0230           All           01       July 30, 2008
    Total Pages: 153

    CF34-BJ S/B 72-0231           All           02       November 26, 2008
    Total Pages: 8

    CF34-AL S/B 72-0245           All           01       July 03, 2008
    Total Pages: 153

    CF34-AL S/B 72-0250           All           01       November 26, 2008
    Total Pages: 9
    ______________________________________________________________________

(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  General
    Electric Company, GE-Aviation, Room 285, 1 Newmann Way, Cincinnati, OH
    45215,  telephone   (513)  552-3272;   fax  (513)   552-3329;  e-mail:
    geae.aoc@ge.com.

(3) You may review copies at  the FAA, New England Region, 12  New England
    Executive  Park,  Burlington,  MA; or  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/cfr/ibr-locations.html.

Issued in Burlington, Massachusetts, on November 18, 2009. Peter A. White,
Assistant   Manager,   Engine   and   Propeller   Directorate,    Aircraft
Certification Service.

FOR FURTHER  INFORMATION CONTACT:  John Frost,  Aerospace Engineer, Engine
Certification Office, FAA, Engine & Propeller Directorate, 12 New  England
Executive  Park,   Burlington,  MA   01803;  e-mail:   john.frost@faa.gov;
telephone (781) 238-7756; fax (781) 238-7199.
PREAMBLE 

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule.

SUMMARY: The FAA is adopting a new airworthiness directive (AD) for GE CF34-1A, CF34-3A, and CF34-3B series turbofan engines. This AD requires removing from service certain part number (P/N) and serial number (SN) fan blades within compliance times specified in this AD, inspecting the fan blade abradable rub strip on certain engines for wear, inspecting the fan blades on certain engines for cracks, inspecting the aft actuator head hose fitting for correct position, and, if necessary, repositioning the hose fitting. This AD results from a report of an under-cowl fire and a failed fan blade. We are issuing this AD to prevent failure of certain P/N and SN fan blades and aft actuator head hoses, which could result in an under-cowl fire and subsequent damage to the airplane.

DATES: This AD becomes effective February 3, 2010. The Director of the Federal Register approved the incorporation by reference of certain publications listed in the regulations as of January 4, 2010.

ADDRESSES: You can get the service information identified in this AD from General Electric Company, GE-Aviation, Room 285, 1 Newmann Way, Cincinnati, OH 45215, telephone (513) 552--3272; fax (513) 552-3329; e- mail: geae.aoc@ge.com. The Docket Operations office is located at Docket Management Facility, U.S. Department of Transportation, 1200 New Jersey Avenue, SE., West Building Ground Floor, Room W12-140, Washington, DC 20590-0001.

FOR FURTHER INFORMATION CONTACT: John Frost, Aerospace Engineer, Engine Certification Office, FAA, Engine & Propeller Directorate, 12 New England Executive Park, Burlington, MA 01803; e-mail: john.frost@faa.gov; telephone (781) 238-7756; fax (781) 238-7199.

SUPPLEMENTARY INFORMATION: The FAA proposed to amend 14 CFR part 39 with a proposed AD. The proposed AD applies to GE CF34-1A, CF34-3A, and CF34-3B series turbofan engines. We published the proposed AD in the Federal Register on April 8, 2009 (74 FR 15896). That action proposed to require removing from service certain P/N and SN fan blades within compliance times specified in the proposed AD, inspecting the fan blade abradable rub strip on certain engines for wear, inspecting the fan blades on certain engines for cracks, inspecting the aft actuator head hose fitting for correct position, and, if necessary, repositioning the hose fitting.

Examining the AD Docket

You may examine the AD docket on the Internet at http:// www.regulations.gov; or in person at the Docket Operations office 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 street address for the Docket Operations office (telephone (800) 647-5527) is provided in the ADDRESSES section. Comments will be available in the AD docket shortly after receipt.

Comments

We provided the public the opportunity to participate in the development of this AD. We have considered the comments received.

Request To Modify Wording in Compliance Paragraphs (f)(2) Through (f)(6)(ii)

One commenter requests that we modify the wording in proposed AD compliance paragraphs (f)(2) through (f)(6)(ii), by adding words that the actions required by GEAE SB CF34-AL S/B 72-0250 apply only to those engines that have not had the actions of GEAE SB CF34-AL S/B 72-0245 performed. The commenter states that GEAE SB CF34-AL S/B 72-0250 only applies to fan blades with SNs listed in GEAE SB CF34-AL S/B 72-0245.
We do not agree. The proposed AD stated in paragraph (f) that only fan blade SNs listed in GEAE SB CF34-AL S/B 72-0245 are affected. That paragraph is now paragraph (h) in this AD, as we recodified the AD paragraphs to add clarification in response to another comment we received. We did not change the AD.

Request for Eddy Current Inspection (ECI) for Fan Blades That Have More than 1,200 Cycles-In-Service (CIS)

Bombardier Flexjet and GE Aviation request that we also include an ECI in the AD for fan blades that have more than 1,200 CIS on the effective date of the AD.
We agree. We changed proposed AD paragraph from "(g)(3) For fan blades, P/N 6018T30P14, with more than 850 cycles-since-new (CSN), but fewer than 1,200 CSN on the effective date of this AD, within 350 CIS after the effective date of this AD, perform an initial ECI of the fan blades for cracks'' to "(k)(3) For fan blades, P/N 6018T30P14, with more than 850 CSN, perform an initial ECI of the fan blades for cracks within 350 CIS after the effective date of this AD'' in this AD.

Under-Cowl Fire Determination of Cause Not Consistent

GE Aviation states that, in the Discussion section of the proposed AD, the statement that it was not possible to determine the cause of the under-cowl fire was not consistent with the GE fire investigation. GE stated that their fire investigation concluded that the most probable cause of the under-cowl fire was the separation of the variable geometry aft actuator head hose from the fuel control.
We do not agree. The exact cause of the fire could not be determined due to the thermal damage. We did not change the AD.

Clarification of Gearbox Separation Statement

GE Aviation states that, in the Discussion section of the proposed AD, the statement that the gearbox separated from the engine needs clarification. GE Aviation states that the gearbox is designed to uncouple from the engine during high-load events such as a fan blade out, and the gearbox is secured to the engine by secondary restraint cables. This uncoupling occurred on the left-hand mount, and should not have contributed to the hose failure if the hose was properly aligned.
We do not agree. The wording is factually correct, and we did not state that the separation caused the fire. We did not change the AD.

Claim That the Fire Event Was a Controlled Fire

GE Aviation claims that the event that this AD results from was a "controlled fire'' as the fire had been put out and did not create a hazard for the airplane.
We do not agree. The fire continued to burn unabated until the unidentified fuel source was exhausted. We did not change the AD.

Recommendation To Include GE Remote Diagnostics

GE Aviation and Mesaba Airlines recommend that GE Remote Diagnostics be included in proposed AD compliance paragraph (f)(6) as an alternate method of compliance (AMOC) for monitoring blade health. GE Aviation also recommends that we allow a recurrent ECI at 600-cycle intervals for consistency between the Regional Jet and Business Jet operators. GE Aviation states that the fan blade tang cracking algorithms developed by GE have been validated analytically, as well as in the field, and contributed substantially to finding three cracked blades during 2008.
We do not agree. We cannot include the GE Remote Diagnostics program, because it is a program outside regulatory control. Further, the program cannot replace a visual inspection to verify fan blade cracks. Finally, no GE service bulletin requirement or FAA requirement exists for ECI of the fan blades operating in engines in the Regional Jet operations. We did not change the AD.

Request To Revise the Wording in Proposed AD Compliance Paragraphs (f) and (g)

GE Aviation requests that we revise the wording in proposed AD compliance paragraphs (f) and (g) to clarify our instructions related to operators who fly a Regional Jet with a CF34-3A1 engine in a Business jet application. The commenter states that GEAE SB CF34-AL S/B 72-0245 and SB CF34-AL S/B 72-0250 apply to a small number of Business Jet operators with the CF34-3A1 engine, who fly under the Regional jet manual.
We agree. We changed the compliance section in this AD by adding the requested information and by recodifying the paragraphs.

Request To Correct a Typographical Error

GE Aviation requests that we correct a service bulletin issue date in paragraph (f), to be July 30, 2008.
We agree. We corrected the date in the AD, which is now in paragraph (h).

Request To Remove Inspection of Rubstrips at CSN

Mesaba Airlines requests that we remove the requirements to inspect the fan blade rub strips on fan blades with more than 1,200 CSN, within 20 CIS of the AD effective date, and on fan blades with fewer than 1,200 CSN, by 1,220 CSN. The commenter requests that we add a rub strip inspection every 75 CIS or 100 hours-in-service, until the fan blades are replaced. The commenter states that it is difficult to know the CSN on each fan blade.
We do not agree. To reduce the risk of fan blade failure, the rub strips need to be inspected as required in the AD. We did not change the AD.

Include a Process for Determining Fan Blade Cyclic Limits

Mesaba Airlines states that the FAA should include a process for determining cyclic limits if the fan blades CIS were not established when the fan blades were introduced into service.
We do not agree. If operators do not track fan blade time or CIS, they will need to apply for an alternative method of compliance (AMOC) to this AD. We did not change the AD.

Request for Separate ADs

Mesaba Airlines requests that we issue separate ADs for the Regional Jet fleet and the Business Jet fleet. The commenter feels the proposed AD is far too complex.
We do not agree. The compliance section in the proposed AD is sufficiently direct. We did not change the AD.

Request To Define Terms

Mesaba Airlines requests that we define the terms "CSLI'' and "HSLI'' in the proposed AD compliance section.
In response, we note that we already did, and direct Mesaba Airlines to paragraph (f)(6) in the proposed AD, and in this AD, to compliance paragraph (h)(6).

Request To Not Include Service Bulletin Requirements

Mesaba Airlines requests that we not include the requirements of paragraph 3.A.(2)(d) of GEAE SB CF34-AL S/B 72-0250 in the AD.
We agree. We did not include those requirements in the AD.

Conclusion

We have carefully reviewed the available data, including the comments received, and determined that air safety and the public interest require adopting the 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 AD.

Costs of Compliance

We estimate that this AD will affect 1,966 engines installed on airplanes of U.S. registry. We estimate that the fan blade inspection and replacement requirement will affect 300 of these engines, and the actuator head hose inspection would affect 1,662 engines. We also estimate that it will take 0.5 work-hour per engine to inspect the fan blade abradable rub strip, 6 work-hours per engine to visually inspect the fan blades, 11 work-hours per engine to perform an eddy current inspection of the fan blades, and 0.25 work-hour per engine to inspect the actuator head hose fitting, and that the average labor rate is $80 per work-hour. Required parts will cost $51,106,600. Based on these figures, we estimate the total cost of the AD to U.S. operators to be $51,184,000.

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 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.
We prepared a summary of the costs to comply with this AD and placed it in the AD Docket. You may get a copy of this summary at the address listed under ADDRESSES.

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 Federal Aviation Administration 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.

Sec. 39.13 [Amended]

2. The FAA amends Sec. 39.13 by adding the following new airworthiness directive: