The Civil Aviation Administration of Israel (CAAI), which is the airworthiness authority for Israel, notified the FAA that an unsafe condition may exist on certain Israel Aircraft Industries, Ltd., Model Galaxy airplanes and Model Gulfstream 200 series airplanes. The CAAI advises of an incident in which the main landing gear (MLG) would not lock in the "up" or "down" position. Although the airplane landed safely, the MLG remained unlocked. Investigation revealed severe internal abrasion of an MLG actuator, which caused metal chips to accumulate in the MLG actuator, preventing full travel of the actuator piston and proper engagement of the downlock mechanism. The severe abrasion has been attributed to metal-to-metal contact between the MLG actuator and piston. Subsequent to the original report, similar conditions have been found on several other airplanes. This condition, if not corrected, could result in failure of an MLG actuator to fully extend and retract,which could prevent proper engagement of the downlock mechanism and result in collapse of the MLG during landing.
Explanation of Relevant Service Information
Israel Aircraft Industries has issued Galaxy Alert Service Bulletin GALAXY-32A-125, Revision 1, dated February 4, 2002, which describes procedures for repetitive visual inspections of the left and right MLG actuators for leakage of hydraulic fluid, and a one-time detailed inspection of the MLG actuators for internal abrasions or scratches. If leakage of hydraulic fluid or internal abrasions or scratches outside certain limits specified in the service bulletin are found on the MLG actuator, the service bulletin specifies that the existing MLG actuator be replaced with either a new, improved actuator, or a new or serviceable actuator that has been inspected for and is without internal abrasions or scratches. Replacement of existing MLG actuators with new, improved actuators eliminates the need for the repetitive inspections. The CAAI classified this service bulletin as mandatory and issued Israeli emergency airworthiness directive 32-02-01-24, dated February 13, 2002, in order to assure the continued airworthiness of these airplanes in Israel.
FAA's Conclusions
These airplane models are manufactured in Israel 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 CAAI has kept the FAA informed of the situation described above. The FAA has examined the findings of the CAAI, reviewed all available information, and determined that AD action is necessary for products of these type designs 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 designs registered in the United States, this AD is being issued to prevent failure of the MLG actuator to fully extend and retract, which could prevent proper engagement of the downlock mechanism and result in collapse of the MLG during landing. This AD requires accomplishment of the actions specified in the service bulletin described previously, except as discussed below. This AD also provides for an optional replacement of the existing MLG actuators with new, improved actuators, which ends the repetitive inspections.
Interim Action
This is considered to be interim action. The FAA is currently considering requiring the replacement of the existing MLG actuators with new, improved actuators, which will end the repetitive inspections required by this AD. However, the planned compliance time for the replacement is sufficiently long so that notice and opportunity for prior public comment will be practicable.
Differences Between This AD, the Service Bulletin, and the Foreign AD
This AD differs from the service bulletin and the parallel Israeli emergency airworthiness directive described previously in the following ways:
The service bulletin and Israeli emergency airworthiness directive specify that the initial inspection for hydraulic leakage must be performed before the next flight. However, this AD specifies that the initial inspection must be done within 3 days after the effective date of this AD. In developing an appropriate compliance time for this AD, the FAA considered not only the CAAI's recommendation, but the degree of urgency associated with addressing the subject unsafe condition, and the average utilization of the affected fleet. In light of these factors, the FAA finds a 3-day compliance time for completing the required actions to be warranted, in that it represents an appropriate interval of time allowable for affected airplanes to continue to operate without compromising safety.
The service bulletin and Israeli emergencyairworthiness directive specify that the inspection for leakage of hydraulic fluid must be done before each flight for 100 flights (flight cycles), at which time the MLG actuators must be replaced with new, improved actuators. This AD provides for such replacement as an option that, if accomplished, ends the required repetitive inspections. As explained previously in the "Interim Action" section of this AD, the FAA is currently considering requiring the replacement of existing MLG actuators with new, improved actuators. Since this AD does not require such replacement, this AD requires the repetitive inspections for leakage to continue until the replacement with new, improved MLG actuators is done.
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 lessthan 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 2002-NM-65-AD." The postcard will be date-stamped and returned to thecommenter.
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: