On December 19, 1997, the FAA issued AD 97-26-22, amendment 39-10265 (62 FR 67552, December 29, 1997), applicable to all EMBRAER Model EMB-120 series airplanes, to require a one-time inspection of the movable backstop of the elevator pitch trim command system to ensure that it is installed correctly, and corrective action, if necessary. That AD also requires installation of a guide to maintain the movable backstop in its correct position. That action was prompted by issuance of mandatory continuing airworthiness information by a foreign civil airworthiness authority. The actions required by that AD are intended to prevent a sudden change in pitch attitude caused by autopilot disconnect, which could result in reduced controllability of the airplane.
Actions Since Issuance of Previous Rule
Since the issuance of AD 97-26-22, the Departmento de Aviacao Civil (DAC), which is the airworthiness authority for Brazil, advises that a recent incident occurredthat was similar to the event specified in the preamble of AD 97-26-22, which revealed that the unsafe condition may still exist.
The manufacturer has issued EMBRAER Service Bulletin S.B. 120-27-0081, dated September 1, 2000. This new service information adds a one-time inspection of the movable backstop of the elevator pitch trim command system and the rigging of the elevator trim to verify proper adjustment of the system and correct rigging of the elevator trim tab, and corrective actions, if necessary. The corrective actions consist of adjusting the system and/or the rigging in accordance with the instructions specified in Chapter 27-32-00 (Flight Controls) of the EMBRAER Maintenance Manual. The new service bulletin also describes procedures for installation of a guide to maintain the movable backstop in position in the spiral groove on the pitch trim right control wheel. That installation was specified in EMBRAER Alert Service Bulletin S.B. 120-27-A081, Change 01, dated October 9, 1997 (referenced as the appropriate source of service information for accomplishment of the actions specified in AD 97-26-22).
The DAC classified this service bulletin as mandatory in order to assure the continued airworthiness of these airplanes in Brazil.
FAA's Conclusions
This airplane model is manufactured in Brazil and is 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 ordevelop on other airplanes of the same type design registered in the United States, this AD supersedes AD 97-26-22 to continue to require a one-time inspection of the movable backstop of the elevator pitch trim command system to ensure that it is installed correctly, and corrective action, if necessary. This AD also continues to require installation of a guide to maintain the movable backstop in its correct position. This amendment adds an additional one-time inspection. The actions are required to be accomplished in accordance with the service bulletin described previously, except as discussed below.
Differences Between Rule and Related Service Information
Operators should note that the service bulletin specifies accomplishment of a one-time inspection of the movable backstop of the elevator pitch trim command system and the rigging of the elevator trim tab within the next 400 flight hours; however, the FAA finds that such a compliance time will not ensure that the inspection is accomplished in a timely manner.
In developing an appropriate compliance time for the inspection, the FAA considered not only the manufacturer's recommendation, but the degree of urgency associated with addressing the subject unsafe condition, as well as the compliance time for the actions required. The FAA finds accomplishment of the one-time inspection within 100 flight hours after the effective date of this AD to be warranted, in that this represents an appropriate amount of time allowable for affected airplanes to continue to operate without compromising safety.
Operators also should note that, while the service bulletin does not specify the type of inspection of the movable backstop of the elevator pitch trim command system and the rigging of the elevator trim tab to detect discrepancies, this AD would require a general visual inspection to detect such discrepancies. A note has been included in this AD to define that inspection.
Interim Action
This is considered to be interim action until final action is identified, at which time the FAA may consider further rulemaking.
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 that involves 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 2000-NM-305-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.
39.13 [Amended]
2. Section 39.13 is amended by removing amendment 39-10265 (62 FR 67552, December 29, 1997), and by adding a new airworthiness directive (AD), amendment 39-11911, to read as follows: