AD 2004-12-12

This amendment adopts a new airworthiness directive (AD), applicable to certain EMBRAER Model EMB-120 series airplanes. This action requires repetitive inspections for cracks or evidence of damage/distortion of the anti-skid drive coupling clips for the hubcaps of the main landing gear (MLG) wheels; repetitive measurement of the gap and height dimensions of the coupling clips; corrective actions, if necessary; and eventual replacement of all coupling clips with new, improved coupling clips. This action is necessary to prevent excessive gaps in the anti-skid drive coupling clips for the hubcaps of the MLG, which could result in momentary loss of the normal braking system at low speeds, and reduced controllability of the airplane. This action is intended to address the identified unsafe condition.

Final rule.

2004-12-12 Empresa Brasileira De Aeronautica S.A. (Embraer): Amendment 39-13671. Docket 2003-NM-79-AD.

Applicability: Model EMB-120 series airplanes having serial numbers 120003, 120004, and 120006 through 120359 inclusive; certificated in any category.

Compliance: Required as indicated, unless accomplished previously.

To prevent excessive gaps in the anti-skid drive coupling clips for the hubcaps of the main landing gear (MLG), which could result in momentary loss of the normal braking system at low speeds, and reduced controllability of the airplane, accomplish the following:

General Visual Inspection, Measurement of Clip Dimensions, and Corrective Actions

(a) Within 400 flight hours or 6 months after the effective date of this AD, whichever occurs first: Do a general visual inspection for cracks or evidence of damage/distortion of the anti-skid drive coupling clips for the MLG wheel hubcap; and measure the "G" (gap) and "H" (height) dimensions of the coupling clips; and do any applicable corrective action; per the Accomplishment Instructions of EMBRAER Service Bulletin 120-32-0088, Revision 01, dated October 1, 2003. Any applicable corrective action must be done prior to further flight per the service bulletin. Repeat the inspection and dimension measurement thereafter at every wheel change or wheel speed transducer change.

Note 1: For the purposes of this AD, a general visual inspection is defined as: "A visual examination of an interior or exterior area, installation, or assembly to detect obvious damage, failure, or irregularity. This level of inspection is made from within touching distance unless otherwise specified. A mirror may be necessary to enhance visual access to all exposed surfaces in the inspection area. This level of inspection is made under normally available lighting conditions such as daylight, hangar lighting, flashlight, or droplight and may require removal or opening of access panels or doors. Stands, ladders,or platforms may be required to gain proximity to the area being checked."

Replacement of Coupling Clips

(b) Within 800 flight hours or 12 months after the effective date of this AD, whichever occurs first: Replace any anti-skid drive coupling clip for the MLG wheel hubcap that was not previously replaced per paragraph (a) of this AD, with a new, improved part specified in and per Part III of EMBRAER Service Bulletin 120-32- 0088, Revision 01, dated October 1, 2003. Repeat the applicable actions required by paragraph (a) of this AD thereafter at every wheel change or wheel speed transducer change.

Parts Installation

(c) As of the effective date of this AD, no person may install an anti-skid drive coupling clip, part number 40-91115, on any airplane, unless the part number is identified as 40-91115 REV. D.

Credit for Actions Done per Previous Issue of Service Bulletin

(d) Accomplishment of the specified actions before the effective date of this AD per EMBRAERService Bulletin 120-32-0088, dated November 18, 2002, is considered acceptable for compliance with the applicable requirements of paragraphs (a) and (b) of this AD.

Alternative Methods of Compliance

(e) In accordance with 14 CFR 39.19, the Manager, International Branch, ANM-116, Transport Airplane Directorate, FAA, is authorized to approve alternative methods of compliance for this AD.

Incorporation by Reference

(f) Unless otherwise specified in this AD, the actions shall be done in accordance with EMBRAER Service Bulletin 120-32-0088, Revision 01, dated October 1, 2003. This incorporation by reference was approved by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies may be obtained from Empresa Brasileira de Aeronautica S.A. (EMBRAER), P.O. Box 343--CEP 12.225, Sao Jose dos Campos--SP, Brazil. Copies may be inspected at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; 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/code_of_federal_regulations/ibr_locations.html .

Note 2: The subject of this AD is addressed in Brazilian airworthiness directive 2003-01-01, dated February 6, 2003.

Effective Date

(g) This amendment becomes effective on July 21, 2004.

A proposal to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) to include an airworthiness directive (AD) that is applicable to certain EMBRAER Model EMB-120 series airplanes was published in the Federal Register on April 6, 2004 (69 FR 17984). That action proposed to require repetitive inspections for cracks or evidence of damage/distortion of the anti-skid drive coupling clips for the hubcaps of the main landing gear (MLG) wheels; repetitive measurement of the gap and height dimensions of the coupling clips; corrective actions, if necessary; and eventual replacement of all coupling clips with new, improved coupling clips.

Comments

Interested persons have been afforded an opportunity to participate in the making of this amendment. No comments were submitted in response to the proposal or the FAA's determination of the cost to the public.

Conclusion

The FAA has determined that air safety and the public interest require theadoption of the rule as proposed.

Cost Impact

We estimate that 220 airplanes of U.S. registry will be affected by this AD.

It will take approximately 2 work hours per airplane to accomplish the required general visual inspection and measurement of dimensions "G" and "H," at an average labor rate of $65 per work hour. Based on these figures, the cost impact of the general visual inspection and measurement of dimensions "G" and "H", on U.S. operators is estimated to be $28,600, or $130 per airplane, per inspection cycle.

It will take approximately 1 work hour per airplane to do the required replacement of the coupling clips, at an average labor rate of $65 per work hour. Required parts will cost approximately $600 per airplane. Based on these figures, the cost impact of the replacement on U.S. operators is estimated to be $146,300, or $665 per airplane.

The cost impact figures discussed above are based on assumptions that no operator has yet accomplished any of the requirements of this AD action, and that no operator would accomplish those actions in the future if this AD were not adopted. The cost impact figures discussed in AD rulemaking actions represent only the time necessary to perform the specific actions actually required by the AD. These figures typically do not include incidental costs, such as the time required to gain access and close up, planning time, or time necessitated by other administrative actions.

Regulatory Impact

The regulations adopted herein 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. Therefore, it is determined that this final rule does not have federalism implications under Executive Order 13132.

For the reasons discussed above, I certify that this action (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. A final evaluation has been prepared for this action and it is contained in the Rules Docket. A copy of it may be obtained from the Rules Docket at the location provided under the caption ADDRESSES.

List of Subjects in 14 CFR Part 39

Air transportation, Aircraft, Aviation safety, Incorporation by reference, Safety.

Adoption of the Amendment

Accordingly, pursuant to the authority delegated to me by the Administrator, the Federal Aviation Administration amends part 39 of the Federal Aviation Regulations (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. Section 39.13 is amended by adding the following new airworthiness directive: