AD 2001-17-04

This amendment adopts a new airworthiness directive (AD) that is applicable to certain EMBRAER Model EMB-135ER and -135LR series airplanes, and Model EMB-145, -145ER, -145MR, and -145LR series airplanes. This action requires a one-time visual inspection to determine if the two bonding jumpers that connect the horizontal stabilizer to the vertical stabilizer are properly installed, and replacement of the jumper with a new jumper, if necessary. This action also requires a one-time visual inspection to determine if the supports that connect the bonding jumpers to the horizontal stabilizer are deformed, and corrective actions, if necessary. This action is necessary to prevent severed bonding jumpers in the event of a lightning strike, which could result in reduced elevator control capability, and consequent reduced controllability of the airplane. This action is intended to address the identified unsafe condition.

Final rule; request for comments.

2001-17-04 Empresa Brasileira de Aeronautica S.A. (EMBRAER): Amendment 39-12395. Docket 2001-NM-249-AD.

Applicability: Model EMB-135ER and -135LR series airplanes, and Model EMB-145, -145ER, -145MR, and -145LR series airplanes, as listed in EMBRAER Alert Service Bulletin 145-55-A025, dated June 5, 2001; certificated in any category.

Note 1: This AD applies to each airplane identified in the preceding applicability provision, regardless of whether it has been modified, altered, or repaired in the area subject to the requirements of this AD. For airplanes that have been modified, altered, or repaired so that the performance of the requirements of this AD is affected, the owner/operator must request approval for an alternative method of compliance in accordance with paragraph (e) of this AD. The request should include an assessment of the effect of the modification, alteration, or repair on the unsafe condition addressed by this AD; and, if the unsafe condition has not been eliminated, the request should include specific proposed actions to address it.

Compliance: Required as indicated, unless accomplished previously.

To prevent severing of the bonding jumpers that connect the vertical stabilizer to the horizontal stabilizer, which could result in reduced elevator control capability, and consequent reduced controllability of the airplane; accomplish the following:

Inspection of the Bonding Jumpers

(a) Within the next 100 flight hours after the effective date of this AD, perform a detailed visual inspection to determine if the two bonding jumpers that connect the horizontal to the vertical stabilizers are properly installed, per EMBRAER Alert Service Bulletin 145-55-A025, dated June 5, 2001.

Note 2: For the purposes of this AD, a detailed visual inspection is defined as: "An intensive visual examination of a specific structural area, system, installation, or assembly to detect damage, failure, or irregularity. Available lighting is normally supplemented with a direct source of good lighting at intensity deemed appropriate by the inspector. Inspection aids such as mirror, magnifying lenses, etc., may be used. Surface cleaning and elaborate access procedures may be required."

Follow-on Action

(b) If both bonding jumpers are installed properly, before further flight, determine if the jumpers are mechanically tensioned to a slack distance of 5 millimeters (mm) or less between the reference line and the jumper as specified in View E of EMBRAER Alert Service Bulletin 145-55-A025, dated June 5, 2001.

(1) If any slack distance is 5 mm or less, before further flight, replace the bonding jumper with a new jumper having part number (P/N) LN926416X165, per the alert service bulletin.

(2) If any slack distance is 6 mm or more, at the time specified in paragraph (d) of this AD, accomplish those actions specified in paragraph (d) of this AD.

Corrective Actions

(c) If either bonding jumper is not installed properly (e.g., misaligned, signs of previous elongation, or damage), before further flight, replace the bonding jumper with a new jumper having P/N LN926416X165, in accordance with EMBRAER Alert Service Bulletin 145-55-A025, dated June 5, 2001.

Inspection of the Connecting Supports

(d) Within the next 100 flight hours after the effective date of this AD, perform a detailed visual inspection to determine if the supports that connect the bonding jumpers to the horizontal stabilizers are deformed, cracked, or ruptured, per EMBRAER Alert Service Bulletin 145-55-A025, dated June 5, 2001.

(1) If no deformation is detected, no further action is required by this paragraph.

(2) If any connecting support having deformation of 30 degrees or less has any sign of a painting discrepancy, before further flight, repaint the support per the alert service bulletin. The support must remain in the position it was found, as specified in the alert service bulletin.

(3) If any connecting support is deformed above 30 degrees or any signs of cracking or ruptures are detected, before further flight, replace the connecting support with a new support per the alert service bulletin.

Alternative Methods of Compliance

(e) An alternative method of compliance or adjustment of the compliance time that provides an acceptable level of safety may be used if approved by the Manager, Atlanta Aircraft Certification Office (ACO), FAA. Operators shall submit their requests through an appropriate FAA Principal Maintenance Inspector, who may add comments and then send it to the Manager, Atlanta ACO.

Note 3: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Atlanta ACO.

Special Flight Permits

(f) Special flight permits may be issued in accordance with sections 21.197 and 21.199 of the Federal Aviation Regulations (14 CFR 21.197 and 21.199) to operate the airplane to a locationwhere the requirements of this AD can be accomplished.

Incorporation by Reference

(g) The actions shall be done in accordance with EMBRAER Alert Service Bulletin 145-55-A025, dated June 5, 2001. 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 FAA, Atlanta Aircraft Certification Office, One Crown Center, 1895 Phoenix Boulevard, suite 450, Atlanta, Georgia; or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC.

Note 4: The subject of this AD is addressed in Brazilian airworthiness directive 2001-06-03, dated June 13, 2001.

Effective Date

(h) This amendment becomes effective onSeptember 5, 2001.

The Departmento de Aviacao Civil (DAC), which is the airworthiness authority for Brazil, recently notified the FAA that an unsafe condition may exist on certain Empresa Brasileira de Aeronautica S.A. (EMBRAER) Model EMB-135ER and -135LR series airplanes, and Model EMB-145, -145ER, -145MR, and -145LR series airplanes. The DAC advises that, during a post-lightning strike inspection of a Model EMB-145 series airplane, the bonding jumpers that electrically bond the vertical and horizontal stabilizers were found to be severed. In addition, one elevator cable was severed and the other elevator cable had arcing damage. The inspection revealed that the bonding jumpers were overstretched and subsequently severed during the lightning strike. When the bonding jumpers severed, they made contact with the elevator cables, which resulted in damage to the elevator cables. This condition, if not corrected, could result in reduced elevator control capability, and consequent reduced controllability of the airplane, due to severed bonding jumpers.

Explanation of Relevant Service Information

EMBRAER has issued Alert Service Bulletin 145-55-A025, dated June 5, 2001, which describes procedures for performing a one-time general visual inspection to determine if the two bonding jumpers that connect the horizontal to the vertical stabilizers are properly installed (not misaligned, damaged, or showing signs of previous elongation), and replacing the bonding jumper with a new jumper, if necessary. The alert service bulletin also specifies procedures for determining if the mechanical tension between the bonding jumpers and the reference line is 5 millimeters or less, and corrective action (replacing the bonding jumper), if necessary. Additionally, the alert service bulletin describes procedures for performing a one-time general visual inspection to determine if the supports that connect the bonding jumpers to the horizontal stabilizer are deformed, cracked, or ruptured. The alert service bulletin describes corrective actions to repair or replace the connecting support with a new connecting support, as applicable. Accomplishment of the actions specified in the alert service bulletin is intended to adequately address the identified unsafe condition. The DAC classified this alert service bulletin as mandatory and issued Brazilian airworthiness directive 2001-06-03, dated June 13, 2001, in order to assure the continued airworthiness of these airplanes in Brazil.

FAA's Conclusions

These airplane models are manufactured in Brazil and are type certificated for operation in the United States under the provisions of section 21.29 of the Federal Aviation Regulations (14 CFR 21.29) and the applicable bilateral airworthiness agreement. Pursuant to this bilateral airworthiness agreement, the DAC has kept the FAA informed of the situation described above. The FAA has examined the findings of the DAC, reviewed all available information, and determined that AD action is necessary for products of this type design that are certificated for operation in the United States.

Explanation of Requirements of Rule

Since an unsafe condition has been identified that is likely to exist or develop on other airplanes of the same type design registered in the United States, this AD is being issued to prevent severed bonding jumpers, which could result in reduced elevator control capability, and consequent reduced controllability of the airplane. This AD requires accomplishment of the actions specified in the alert service bulletin described previously, except as discussed below.

Difference Between This AD and the EMBRAER Alert Service Bulletin

The EMBRAER alert service bulletin specifies that any bonding jumper that is mechanically tensioned outside the limits specified in the alert service bulletin may be replaced within the next 100 flight hours after the inspection. This AD, however, requires that the replacement of a bonding jumper, if necessary, must be accomplished before further flight after the inspection. In developing an appropriate compliance time for this AD, the FAA considered not only the DAC's requirements in the Brazilian airworthiness directive and the manufacturer's recommendations, but the degree of urgency associated with addressing the subject unsafe condition, the average utilization of the affected fleet, and the time necessary to perform the inspection (less than one hour). In light of all of these factors, the FAA finds that the "before further flight" compliance time, in this case, to be warranted.

Determination of Rule's Effective Date

Since a situation exists that requires the immediate adoption of this regulation, it is found that notice and opportunity for prior public comment hereon are impracticable, and that good cause exists for making this amendment effective in less than 30 days.

Comments Invited

Although this action is in the form of a final rule thatinvolves requirements affecting flight safety and, thus, was not preceded by notice and an opportunity for public comment, comments are invited on this rule. Interested persons are invited to comment on this rule by submitting such written data, views, or arguments as they may desire. Communications shall identify the Rules Docket number and be submitted in triplicate to the address specified under the caption ADDRESSES. All communications received on or before the closing date for comments will be considered, and this rule may be amended in light of the comments received. Factual information that supports the commenter's ideas and suggestions is extremely helpful in evaluating the effectiveness of the AD action and determining whether additional rulemaking action would be needed.

Submit comments using the following format:

Organize comments issue-by-issue. For example, discuss a request to change the compliance time and a request to change the service bulletin reference as two separate issues.

For each issue, state what specific change to the AD is being requested.

Include justification (e.g., reasons or data) for each request.

Comments are specifically invited on the overall regulatory, economic, environmental, and energy aspects of the rule that might suggest a need to modify the rule. All comments submitted will be available, both before and after the closing date for comments, in the Rules Docket for examination by interested persons. A report that summarizes each FAA-public contact concerned with the substance of this AD will be filed in the Rules Docket.

Commenters wishing the FAA to acknowledge receipt of their comments submitted in response to this rule must submit a self-addressed, stamped postcard on which the following statement is made: "Comments to Docket Number 2001-NM-249-AD." The postcard will be date stamped and returned to the commenter.

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.

The FAA has determined that this regulation is an emergency regulation that must be issued immediately to correct an unsafe condition in aircraft, and that it is not a "significant regulatory action" under Executive Order 12866. It has been determined further that this action involves an emergency regulation under DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979). If it is determined that this emergency regulation otherwise would be significant under DOT Regulatory Policies and Procedures, a final regulatory evaluation will be prepared and placed in the Rules Docket. A copy of it, if filed, 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.

Sec. 39.13 [Amended]

2. Section 39.13 is amended by adding the following new airworthiness directive: