## 69056 Federal Register / Vol. 70, No. 218 / Monday, November 14, 2005 / Rules and Regulations
**DEPARTMENT OF TRANSPORTATION Federal Aviation Administration**  **14 CFR Part 39 [Docket No. FAA** 
**– 2005** 
**– 22110; Directorate**  **Identifier 2004**
**– NM** 
**– 205** 
**– AD; Amendment**  **39**
**– 14366; AD 2005** 
**– 23** 
**– 08]**  **RIN 2120**
**– AA64**  

### Airworthiness Directives; Airbus Model **A300 B4**
**– 600 and A300 B4** 
**– 600R Series**  **Airplanes; and A300 F4**
**– 605R and**  **A300 C4**
**– 605R Variant F Airplanes**  **AGENCY** 

### : Federal Aviation Administration (FAA), Department of Transportation (DOT). **ACTION** 

### : Final rule. **SUMMARY** 

### : The FAA is superseding an existing airworthiness directive (AD), which applies to all Airbus Model A300 B4

– 600 and A300 B4

– 600R series airplanes, and all Model A300 F4

– 605R airplanes. That AD currently requires repetitive inspections to detect cracks of certain attachment holes, installation of new fasteners, follow-on inspections or repair if necessary, and modification of the angle fittings of fuselage frame FR47. This new AD revises certain inspection thresholds and intervals. This new AD also adds inspections to detect cracks of additional attachment holes. This AD results from reports of cracks found before the inspection thresholds in the existing AD and cracks found in nearby areas not inspected by the existing AD. We are issuing this AD to prevent fatigue cracking of the forward fitting of fuselage frame FR47, which could result in reduced structural integrity of the frame. **DATES** 

### : This AD becomes effective December 19, 2005.

The Director of the Federal Register approved the incorporation by reference of certain publications listed in the AD as of December 19, 2005.

On July 8, 2002 (67 FR 38193, June 3, 2002), the Director of the Federal Register approved the incorporation by reference of Airbus Service Bulletin A300

– 57

– 6086, dated June 6, 2000. **ADDRESSES** 

### : You may examine the AD docket on the Internet at http:// dms.dot.gov or in person at the Docket Management Facility, U.S. Department of Transportation, 400 Seventh Street, SW., Nassif Building, room PL

– 401, Washington, DC.

Contact Airbus, 1 Rond Point Maurice Bellonte, 31707 Blagnac Cedex, France, for service information identified in this AD. **FOR FURTHER INFORMATION CONTACT** 

### : Dan Rodina, Aerospace Engineer, International Branch, ANM

– 116, FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington 98055

– 4056; telephone (425) 227

– 2125; fax (425) 227

– 1149. **SUPPLEMENTARY INFORMATION** 

### : Examining the Docket

You may examine the airworthiness directive (AD) docket on the Internet at http://dms.dot.gov or in person at the Docket Management Facility office between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The Docket Management Facility office (telephone (800) 647

– 5227) is located on the plaza level of the Nassif Building at the street address stated in the **ADDRESSES** 

### section. Discussion

The FAA issued a notice of proposed rulemaking (NPRM) to amend 14 CFR part 39 to include an AD that supersedes AD 2002

– 11

– 04, amendment 39

– 12765 (67 FR 38193, June 3, 2002). The existing AD applies to all Airbus Model A300 B4

– 600 and A300 B4

– 600R series airplanes, and all Model A300 F4

– 605R airplanes. That NPRM was published in the Federal Register on August 16, 2005 (70 FR 48085). That NPRM proposed to continue to require repetitive inspections to detect cracks of certain attachment holes, installation of new fasteners, follow-on inspections or repair if necessary, and modification of the angle fittings of fuselage frame FR47. That NPRM also proposed to revise certain inspection thresholds and intervals and add inspections to detect cracks of additional attachment holes. Comments

We provided the public the opportunity to participate in the development of this AD. We have considered the comment that has been received on the NPRM. Request To Clarify Inspection in Paragraph (k)

One commenter, the manufacturer, requests that we clarify the inspection specified in paragraph (k) of the NPRM. The commenter states that the inspection of hole T is not required if

‘‘ any cracking is found ’’ but is required only if cracking is found at hole G.

We agree with the commenter that the inspection of hole T is required only if cracking is found at hole G. As specified in the Accomplishment Instructions of Airbus Service Bulletin A300

– 57

– 6086, Revision 01, dated April 2, 2002 (which is referenced as the appropriate source of service information for accomplishing the required actions for certain airplanes), the inspection of hole T is applicable only if cracking is found at hole G. For clarity, we have revised paragraph (k) of the final rule. Clarification of Service Bulletin References

We have revised certain references to the service bulletins for clarity. We have clarified that the actions specified in paragraphs (j) and (k) of the final rule are done in accordance with the Accomplishment Instructions of Airbus Service Bulletin A300

– 57

– 6086, Revision 01, dated April 2, 2002. We have also clarified that the modifications specified in paragraph (l) of the final rule are done in accordance with the Accomplishment Instructions of Airbus Service Bulletin A300

– 57

– 6050, Revision 03, dated May 31, 2001. Clarification of Alternative Method of Compliance (AMOC) Paragraph

We have revised this action to clarify the appropriate procedure for notifying the principal inspector before using any approved AMOC on any airplane to which the AMOC applies. Conclusion

We have carefully reviewed the available data, including the comment that has been 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

The following table provides the estimated costs for U.S. operators to comply with this AD. This AD will affect about 74 airplanes of U.S. registry.


## 69057 Federal Register / Vol. 70, No. 218 / Monday, November 14, 2005 / Rules and Regulations
E STIMATED 

### C OSTS

Action Work hours Average labor rate per hour Parts Cost per airplane Fleet cost
Inspection per Airbus Service

Bulletin A300

– 57

– 6049. 13 $65 $0 $845 ........................................ $62,530, per inspection cycle. Inspection per Airbus Service

Bulletin A300

– 57

– 6086. 30 65 6,637

– 19,091 $8,587

– $21,041, per inspection cycle. $635,438

– $1,557,034, per inspection cycle.Modification per Airbus Service Bulletin A300

– 57

– 6050. 65

– 365 65 3,370 $7,595

– $27,095 ...................... $562,030

– $2,005,030.



### 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 regulatory evaluation of the estimated costs to comply with this AD and placed it in the AD docket. 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, 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 Federal Aviation Administration (FAA) amends § 39.13 by removing amendment 39

– 12765 (67 FR 38193, June 3, 2002) and by adding the following new airworthiness directive (AD): 2005

– 23

– 08 Airbus: Amendment 39

– 14366. Docket No. FAA

– 2005

– 22110; Directorate Identifier 2004

–NM

– 205

–AD. Effective Date

(a) This AD becomes effective December 19, 2005. Affected ADs

(b) This AD supersedes AD 2002

– 11

– 04. Applicability

(c) This AD applies to Airbus Model A300 B4

– 601, B4

– 603, B4

– 620, and B4

– 622 airplanes; Model A300 B4

– 605R and B4

– 622R airplanes; Model A300 F4

– 605R airplanes; and Model A300 C4

– 605R Variant F airplanes; certificated in any category; except airplanes on which Airbus Modification 12171 or 12249 has been accomplished or on which Airbus Service Bulletin A300

– 57

– 6069 has been accomplished. Unsafe Condition

(d) This AD was prompted by reports of cracks found before the inspection thresholds in the existing AD and cracks found in nearby areas not inspected by the existing AD. We are issuing this AD to prevent fatigue cracking of the forward fitting of fuselage frame FR47, which could result in reduced structural integrity of the frame. 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. Inspections for Attachment Holes on the Internal Angles of the Wing Center Box, and Corrective Action

(f) Perform a rotating probe inspection to detect cracking of the applicable attachment holes on the left and right internal angles of the wing center box in accordance with the Accomplishment Instructions of Airbus Service Bulletin A300

– 57

– 6049, Revision 06, dated July 15, 2004. Do the inspection at the applicable time specified by paragraph 1.E.(2), Accomplishment Timescale, of Revision 06 of the service bulletin, except as required by paragraph (m) of this AD. Repeat the rotating probe inspection specified in this paragraph thereafter at intervals not to exceed the applicable interval specified in Revision 06 of the service bulletin, except that all touch-and-go landings must be counted in determining the total number of flight cycles between consecutive inspections.

(g) If no cracking is found during any inspection required by paragraph (f) of this AD: Prior to further flight, install new fasteners in accordance with the Accomplishment Instructions of Airbus Service Bulletin A300

– 57

– 6049, Revision 06, dated July 15, 2004.

(h) If any cracking is found during any inspection required by paragraph (f) of this AD: Prior to further flight, perform applicable corrective actions (including reaming, drilling, drill-stopping holes, chamfering, performing follow-on inspections, and installing new or oversize fasteners) in accordance with the Accomplishment Instructions of Airbus Service Bulletin A300

– 57

– 6049, Revision 06, dated July 15, 2004, except as required by paragraph (n) of this AD. Inspections for Attachment Holes in the Horizontal Flange of the Internal Corner Angle Fitting of Fuselage Frame FR47, and Corrective Action

(i) Perform a rotating probe inspection to detect cracking of the applicable attachment holes in the horizontal flange of the internal corner angle fitting of fuselage frame FR47, in accordance with the Accomplishment Instructions of Airbus Service Bulletin A300

– 57

– 6086, Revision 01, dated April 2, 2002. Do the inspection at the applicable time specified in paragraph 1.E., Compliance, of Airbus Service Bulletin A300

– 57

– 6086,


## 69058 Federal Register / Vol. 70, No. 218 / Monday, November 14, 2005 / Rules and Regulations Revision 01, dated April 2, 2002, except as provided by paragraph (m) of this AD; or within 1,500 flight cycles after July 8, 2002 (the effective date of AD 2002

– 11

– 04, amendment 39

– 12765); whichever occurs later. Repeat the rotating probe inspection specified in this paragraph thereafter at intervals not to exceed the applicable interval specified in Airbus Service Bulletin A300

– 57

– 6086, dated June 6, 2000, except that all touch-and-go landings must be counted in determining the total number of flight cycles between consecutive inspections.

(j) If no cracking is found during any inspection required by paragraph (i) of this AD: Prior to further flight, install new fasteners in accordance with the Accomplishment Instructions of Airbus Service Bulletin A300

– 57

– 6086, Revision 01, dated April 2, 2002.

(k) If any cracking is found during any inspection required by paragraph (i) of this AD: Prior to further flight, perform applicable corrective actions (including inspecting hole T if any cracking is found at hole G, reaming the holes, and installing oversize fasteners) in accordance with the Accomplishment Instructions of Airbus Service Bulletin A300

– 57

– 6086, Revision 01, dated April 2, 2002, except as required by paragraph (n) of this AD. Modification of Angle Fittings of the Wing Center Box

(l) Modify the left and right internal angle fittings of the wing center box. The modification includes performing a rotating probe inspection to detect cracking, repairing cracks, cold expanding holes, and installing medium interference fitting bolts. Perform the modification in accordance with the Accomplishment Instructions of Airbus Service Bulletin A300

– 57

– 6050, Revision 03, dated May 31, 2001; and at the applicable time specified by paragraph 1.B.(4), Accomplishment Timescale, of Airbus Service Bulletin A300

– 57

– 6050, Revision 03, dated May 31, 2001; except as required by paragraphs (m) and (n) of this AD. Exceptions to Specifications in Service Bulletins

(m) Where the service bulletins specified in paragraphs (f), (i), and (l) of this AD specify a grace period relative to receipt of the service bulletin, this AD requires compliance within the applicable grace period following the effective date of this AD, if the threshold has been exceeded. (n) If any crack is detected during any inspection required by this AD, and the applicable service bulletin specifies to contact the manufacturer for disposition of certain corrective actions: Prior to further flight, repair in accordance with a method approved by either the Manager, International Branch, ANM

– 116, Transport Airplane Directorate, FAA; or the Direction Ge

 ́ ne

 ́ rale de l ’ Aviation Civile (DGAC) (or its delegated agent). Actions Accomplished According to Previous Issue of Service Bulletins

(o) Actions accomplished prior to the effective date of this AD in accordance with Airbus Service Bulletin A300

– 57

– 6086, dated June 6, 2000, are acceptable for compliance with the requirements of paragraph (i) of this AD.

(p) Modifications accomplished prior to the effective date of this AD in accordance with Airbus Service Bulletin A300

– 57

– 6050, Revision 02, dated February 10, 2000; are acceptable for compliance with the requirements of paragraph (l) of this AD. No Reporting Requirement

(q) Although Airbus Service Bulletin A300

– 57

– 6049, Revision 06, dated July 15, 2004; and Airbus Service Bulletin A300

– 57

– 6086, Revision 01, dated April 2, 2002; specify to submit certain information to the manufacturer, this AD does not include that requirement. Alternative Methods of Compliance (AMOCs)

(r)(1) The Manager, International Branch, ANM

– 116, Transport Airplane Directorate, FAA, has the authority to approve AMOCs for this AD, if requested in accordance with the procedures found in 14 CFR 39.19.

(2) Before using any AMOC approved in accordance with 14 CFR 39.19 on any airplane to which the AMOC applies, notify the appropriate principal inspector in the FAA Flight Standards Certificate Holding District Office.

(3) AMOCs approved previously according to AD 2002

– 11

– 04, are not approved as AMOCs with this AD. Related Information

(s) French airworthiness directive F

– 2004

– 159, dated September 29, 2004, also addresses the subject of this AD. Material Incorporated by Reference

(t) You must use the service bulletins listed in Table 1 of this AD to perform the actions that are required by this AD, unless the AD specifies otherwise.

(1) The Director of the Federal Register approved the incorporation by reference of the service bulletins listed in Table 2 of this AD in accordance with 5 U.S.C. 552(a) and 1 CFR part 51.

(2) On July 8, 2002 (67 FR 38193, June 3, 2002), the Director of the Federal Register approved the incorporation by reference of Airbus Service Bulletin A300

– 57

– 6086, dated June 6, 2000.

(3) Contact Airbus, 1 Rond Point Maurice Bellonte, 31707 Blagnac Cedex, France, for a copy of this service information. You may review copies at the Docket Management Facility, U.S. Department of Transportation, 400 Seventh Street, SW., room PL

– 401, Nassif Building, Washington, DC; on the Internet at http://dms.dot.gov; or at the National Archives and Records Administration (NARA). For information on the availability of this material at the NARA, call (202) 741

– 6030, or go to http:// www.archives.gov/federal

_register/ code

_ of

_ federal

_regulations/ ibr

_locations.html

. 

### T ABLE 

### 1.

—A LL 

### M ATERIAL 

### I NCORPORATED BY 

### R EFERENCE
Airbus service bulletin Revision level Date
A300

– 57

– 6049,

excluding Appendix 01. 06 ............ July 15, 2004.

A300

– 57

– 6050 03 ............ May 31, 2001. A300

– 57

– 6086 Original .... June 6, 2000. A300

– 57

– 6086 01 ............ April 2, 2002.


### T ABLE 

### 2.

— N EW 

### M ATERIAL 

### I NCORPORATED BY 

### R EFERENCE
Airbus service bulletin Revision level Date
A300

– 57

– 6049,

excluding Appendix 01. 06 ............ July 15, 2004.

A300

– 57

– 6050 03 ............ May 31, 2001. A300

– 57

– 6086 01 ............ April 2, 2002.

Airbus Service Bulletin A300

– 57

– 6050, Revision 03, dated May 31, 2001, contains the following effective pages:

Page number Revision level shown on

page Date shown on page
1, 4, 10A

– 11, 75

– 76 ............................................................................................................................. ................. 03 ............ May 31, 2001. 2, 8

– 9, 17

– 32, 41

–42, 57

– 58, 61

– 63, 77 ............................................................................................................. 02 .......... .. February 10, 2000. 3, 5

– 7, 10, 12, 33

– 34, 37

– 38, 47, 59

– 60 ............................................................................................................. 01 ............ Ma y 31, 1999. 13

– 16, 35

– 36, 39

–40, 43

–46, 48

– 56, 64

– 74 ........................................................................................................ Original .... September9, 1994.


## 69059 Federal Register / Vol. 70, No. 218 / Monday, November 14, 2005 / Rules and Regulations Issued in Renton, Washington, on October 31, 2005. Ali Bahrami, Manager, Transport Airplane Directorate, Aircraft Certification Service. [FR Doc. 05

– 22216 Filed 11

– 10

– 05; 8:45 am] **BILLING CODE 4910**
**– 13** 
**– P** 


### DEPARTMENT OF TRANSPORTATION **Federal Aviation Administration 14 CFR Part 39**  **[Docket No. FAA**
**– 2005** 
**– 20947; Directorate**  **Identifier 2004**
**– NM** 
**– 245** 
**– AD; Amendment**  **39**
**– 14364; AD 2005** 
**– 23** 
**– 06]**  **RIN 2120**
**– AA64**  

### Airworthiness Directives; Learjet **Model 23, 24, 24A, 24B, 24B**
**– A, 24D,**  **24D**
**– A, 24E, 24F, 25, 25A, 25B, 25C,**  **25D, and 25F Airplanes Modified by Supplemental Type Certificate**  **SA1731SW, SA1669SW, or SA1670SW AGENCY**  

### : Federal Aviation Administration (FAA), Department of Transportation (DOT). **ACTION** 

### : Final rule. **SUMMARY** 

### : The FAA is adopting a new airworthiness directive (AD) for certain Learjet Model 23, 24, 24A, 24B, 24B

–A, 24D, 24D

–A, 24E, 24F, 25, 25A, 25B, 25C, 25D, and 25F airplanes. This AD requires removing the thrust reverser accumulator, and making the thrust reverser hydraulic system and the thrust reversers inoperable. This AD results from reports of the failure of two thrust reverser accumulators. We are issuing this AD to prevent failure of the thrust reverser accumulators, due to fatigue cracking on the female threads, which could result in the loss of hydraulic power and damage to the surrounding airplane structure. **DATES** 

### : This AD becomes effective December 19, 2005.

The Director of the Federal Register approved the incorporation by reference of a certain publication listed in the AD as of December 19, 2005. **ADDRESSES** 

### : You may examine the AD docket on the Internet at http:// dms.dot.gov or in person at the Docket Management Facility, U.S. Department of Transportation, 400 Seventh Street, SW., Nassif Building, Room PL

– 401, Washington, DC.

Contact The Nordam Group, Nacelle/ Thrust Reverser Systems Division, 6911 North Whirlpool Drive, Tulsa, Oklahoma 74117, for service information identified in this AD. **FOR FURTHER INFORMATION CONTACT** 

### : Jim Rankin, Aerospace Engineer, Special Certification Office, ASW

– 190, FAA, Rotorcraft Directorate, 2601 Meacham Boulevard, Fort Worth, Texas 76137

– 4298; telephone (817) 222

– 5138; fax (817) 222

– 5785. **SUPPLEMENTARY INFORMATION** 

### : Examining the Docket

You may examine the AD docket on the Internet at http://dms.dot.gov or in person at the Docket Management Facility office between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The Docket Management Facility office (telephone (800) 647

– 5227) is located on the plaza level of the Nassif Building at the street address stated in the **ADDRESSES** 

### section. Discussion

The FAA issued a notice of proposed rulemaking (NPRM) to amend 14 CFR part 39 to include an AD that would apply to certain Learjet Model 23, 24, 24A, 24B, 24B

–A, 24D, 24D

–A, 24E, 24F, 25, 25A, 25B, 25C, 25D, and 25F airplanes. That NPRM was published in the Federal Register on April 14, 2005 (70 FR 19718). That NPRM proposed to require removing the thrust reverser accumulator, and making the thrust reverser hydraulic system and the thrust reversers inoperable. Comments

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

One commenter does not support the NPRM. The commenter asserts that deactivating the thrust reversers will cause more accidents, especially under wet or winter runway conditions. The commenter also asserts that one in-flight failure of a thrust reverser does not justify the NPRM given the countless safe operations without thrust reverser failures. The commenter states that

‘‘ [the FAA] also [has] not looked or measured the increase of accidents that will be caused by this [NPRM]. ’’ As further justification for not supporting the NPRM, the commenter states that the NPRM does not account for the cost of brake and tire wear that would be incurred if the thrust reversers are deactivated. We infer that the commenter would like us to withdraw the NPRM.

We do not agree, since we have determined that an unsafe condition exists, and that the interim actions of this AD are necessary to ensure the continued safety of the affected fleet. The one thrust reverser failure on a Learjet Model 25B airplane that occurred in flight led to an emergency landing. A second failure occurred during proof testing and resulted in injury to a person. We acknowledge the commenter ’ s concern with deactivating the thrust reversers; however, the affected Model 23, 24, 24A, 24B, 24B

– A, 24D, 24D

–A, 24E, 24F, 25, 25A, 25B, 25C, 25D, and 25F airplanes were not originally type certificated with thrust reversers installed. Furthermore, we estimate that half of these Learjet model airplanes in service today are operating without thrust reversers. Therefore, an increase in accidents due to deactivation of the affected thrust reversers is unlikely.

Regarding the cost impact of this AD, we point out that the economic analysis of the AD is limited only to the cost of actions actually required by the AD; it does not include incidental costs. In any case, we have determined that direct and incidental costs are outweighed by the safety benefits of this AD. Therefore, no change to this AD is necessary in this regard. Request To Revise Requirements of NPRM

Two commenters request that we revise the NPRM to require repetitive nondestructive testing or x-ray inspections of the thrust reverser accumulator, instead of proposing to deactivate the thrust reversers. One of the commenters states that inspection of the suspected point of failure (the female threads of the accumulator) would be sufficient to prevent failure of the thrust reverser accumulator. The commenter suggests that deactivation of the thrust reversers could be required if damage is found during an inspection.

We do not agree, since the commenters provide no technical justification for revising the requirements of this AD. The history of crack growth on the affected thrust reversers is unknown. In addition, there have been no studies done to determine an appropriate inspection interval for providing an acceptable level of safety. As stated in the NPRM, the parts manufacturer currently is developing a modification that will address the unsafe condition of this AD. Once this modification is developed, approved, and available, we may consider additional rulemaking. Therefore no change to this AD is necessary in this regard. Request To Expand Applicability

One commenter, the parts manufacturer, requests that we delete reference to Supplemental Type Certificates (STCs) SA1731SW, SA1669SW, and SA1670SW from the