On January 23, 2004, the FAA issued emergency AD 2004-02-51, which is applicable to all EMBRAER Model EMB- 135 and -145 series airplanes.
Background
The FAA has received a report that the flightcrew of an EMBRAER Model EMB-135 series airplane experienced rudder control difficulties during takeoff. The airplane made an emergency landing; no injuries were reported. Investigation revealed that the upper and lower control rods for the aft rudder section had failed. (The rudder is composed of a forward and an aft section.) The National Transportation Safety Board is currently investigating the cause of the control rod failure. The airplane on which the incident occurred had accumulated 6,804 total flight hours and 6,371 total flight cycles. Although the effect is unknown at this time, the airplane was operating without Access Panel 312AR, as allowed by the Configuration Deviation List (CDL). Failure of these control rods, if not corrected, could result inloss of rudder control, or a possible rudder jam. Also, an unrestrained aft rudder could enter a flutter mode, which could result in loss of control of the airplane.
The rudder control rods on all EMBRAER Model EMB-135 and -145 series airplanes are identical to those on the affected Model EMB-135 airplane. Therefore, all of these airplanes may be subject to the same unsafe condition.
Explanation of Relevant Service Information
EMBRAER has issued Alert Service Bulletin 145-27-A105, dated January 23, 2004, which describes procedures for:
A one-time visual inspection, including measurement, of the aft rudder control rods to determine if they are assembled correctly and to detect signs of structural damage, cracks, pitting, or deformation.
If any discrepancy is found, replacement of the control rods with new rods, accomplishment of a backlash test to determine the condition of the rudder bearings, and accomplishment of any related applicable corrective action.
Theservice bulletin also recommends that any airplane without Access Panel 312AR installed should have the panel reinstalled.
The Departmento de Aviacao Civil (DAC), which is the airworthiness authority for Brazil, classified this service bulletin as mandatory and issued Brazilian emergency airworthiness directive 2004-01-07, dated January 23, 2004, to ensure 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 the Requirements of the Rule
Since the unsafe condition described is likely to exist or develop on other airplanes of the same type design registered in the United States, the FAA issued emergency AD 2004-02-51 to detect and correct failure of the control rods for the aft rudder, which could result in loss of control of the airplane. The AD requires accomplishment of the following actions per the service bulletin described previously (except as discussed below under the heading "Difference Between This AD and the Service Bulletin"):
A one-time general visual inspection of the aft rudder control rods to detect any discrepancy (including, but not limited to, incorrect installation, corrosion pitting, cracking, looseness, deformity, or structural damage).
If any discrepancy is found, replacement of the affected aft rudder control rod with a new or serviceable control rod, accomplishment of a backlash test (to detect worn rudder bearings) and any applicable corrective action, and submission of the inspection results to the FAA.
This AD also requires the following actions, which are also specified by the parallel Brazilian emergency airworthiness directive:
A general visual inspection to determine if Access Panel 312AR is installed, and re-installing the panel.
A revision to the CDL to remove reference to Access Panel 312AR (thus prohibiting operation without that access panel installed).
Since it was found that immediate corrective action was required, notice and opportunity for prior public comment thereon were impracticable and contrary to the public interest, and good cause existed to make the AD effective immediately by individual notices issued on January 23, 2004, to all known U.S. owners and operators of EMBRAER Model EMB-135 and -145 series airplanes. These conditions still exist, and the AD is hereby published in the Federal Register as an amendment to section 39.13 of the Federal Aviation Regulations (14 CFR 39.13) to make it effective as to all persons.
Difference Between This AD and the Service Bulletin
Although the service bulletin recommends that all inspection results, whether positive or negative, be reported to the manufacturer, this AD requires operators to submit a report to us only if a discrepancy is found.
Differences Between This AD and the Parallel Brazilian Emergency Airworthiness Directive
The Brazilian emergency airworthiness directive specifies that, if any discrepancy is found, both control rods must be replaced. However, this AD requires that only discrepant control rods must be replaced before further flight. We find that replacement of only discrepant control rods will adequately address the unsafe condition.
Also, the Brazilian airworthiness directive specifies that, if Access Panel 312AR is missing, this panel must be installed before the next flight. However, this AD requires that this panel must beinstalled within 10 flight cycles after the inspection. In developing an appropriate compliance time for this installation, we considered the degree of urgency associated with the subject unsafe condition, the average utilization of the affected fleet, and the availability of necessary parts. In light of all of these factors, we find that a 10- flight-cycle compliance time represents an appropriate interval of time for affected airplanes to continue to operate without compromising safety.
We have coordinated these differences with the DAC, and they concur.
Interim Action
This is considered to be interim action. The inspection report that is required by this AD will enable us, the DAC, and the manufacturer to obtain better insight into the unsafe condition, and eventually to develop further action to address the unsafe condition, if necessary. If further action is identified, we may consider further rulemaking.
Special Flight Permits
On July 10, 2002, the FAA issued a new version of 14 CFR part 39 (67 FR 47997, July 22, 2002), which governs the FAA's airworthiness directives system. As amended, part 39 provides for the FAA to add special requirements for operating an airplane to a repair facility to do the work required by an airworthiness directive. For the purposes of this AD, we have determined that a special flight permit would be permitted, but with certain limitations.
Explanation of Editorial Change
In emergency AD 2004-02-51, the definition of a general visual inspection was incorrectly numbered as Note 2. It is actually Note 1. We have revised the number in this document.
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 maydesire. 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.
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 this 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 2004-NM-14-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 Policiesand 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 adding the following new airworthiness directive: