On December 23, 1996, the FAA issued AD 96-26-07, amendment 39-9871 (62 FR 15, January 2, 1997), applicable to all Boeing Model 737 series airplanes, to require revising the FAA-approved Airplane Flight Manual (AFM) to include procedures that will enable the flight crew to take appropriate action to maintain control of the airplane during an uncommanded yaw or roll condition, and to correct a jammed or restricted flight control condition. That action was prompted by an FAA determination that such procedures were not defined adequately in the AFM for these airplanes. Because of the potential for uncommanded yaw or roll conditions in these airplanes, and jammed or restricted flight controls, the actions required by that AD are intended to provide the flight crew with a systematic means to isolate flight control hydraulics, eliminate a rudder hardover, and land safely. \n\nActions Since Issuance of Previous Rule \n\n\tSince the issuance of AD 96-26-07, the FAA has received information from the Independent 737 Flight Controls Engineering and Test Evaluation Board (ETEB) verifying several failure modes in the rudder system of Model 737-100 and -200 (Initial); 737-300, -400, and -500 (Classic); and 737-600, -700, and -800 (Next Generation) series airplanes that can cause an uncommanded rudder hardover. The failure modes include several single jam modes that can cause an uncommanded rudder hardover, in addition to several latent failures or jams that, when combined with a second failure or jam, could cause an uncommanded rudder hardover. Changes in maintenance procedures will be adopted to enhance the detection of latent failure conditions, reducing the potential for an uncommanded hardover. To eliminate these rudder failure modes, the manufacturer is redesigning the rudder system. \n\n\tThe procedure required by AD 96-26-07, and revised by this AD, is not as complete a solution to the rudder hardover concern as is the rudder system redesign, for two reasons: \n\n First, the procedure is not effective throughout the entire flight envelope, having limited effectiveness during the remote possibility of a hardover during takeoff and landing. \n Second, as a general principal, eliminating the possibility of an in-flight situation is a better alternative than relying on flight crew action to correct such a situation. \n\n\tThe rudder system redesign is likely to eliminate the need for procedures dealing with jammed or restricted flight control conditions, but retrofit of the hardware on existing airplanes will take several years to complete. During this time, procedures for jammed or restricted flight control conditions will continue to be necessary. The ETEB determined that the AFM procedure addressing a jammed or restricted rudder required by AD 96-26-07 is inadequate and must be revised. During evaluations of the existing procedure, the ETEB determined that flight crews were confused by the procedure and were not alwaysable to complete it during simulated rudder system malfunctions. Therefore, the FAA has determined that a revised procedure titled "Uncommanded Rudder," in lieu of the existing procedure titled "Jammed or Restricted Rudder," is necessary in the interim period to ensure airplane safety.\n\n Explanation of Requirements of Rule \n\tSince an unsafe condition has been identified that is likely to exist or develop on other airplanes of this same type design, this AD supersedes AD 96-26-07 to require revising the AFM procedure in the existing AD to simplify the instructions for correcting a jammed or restricted flight control condition.\n\n Interim Action \n\tThis is considered to be interim action. As previously stated, once the rudder system is redesigned, and the retrofitted rudder is approved and available, the FAA may consider additional rulemaking. \n\nDetermination of Rule's Effective Date \n\tSince a situation exists that requires the immediate adoption of this regulation, it is foundthat 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. \n\nComments Invited \n\tAlthough 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. \n\n\tSubmit comments using the following format: \n\n 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. \n For each issue, state what specific change to the AD is being requested.\n Include justification (e.g., reasons or data) for each request. \n\n\tComments 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. \n\n\tCommenters 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-325-AD." The postcard will be date stamped and returned to the commenter.\n\n Regulatory Impact \n\tThe 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. \n\n\tThe 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."\n\n List of Subjects in 14 CFR Part 39 \n\tAir transportation, Aircraft, Aviation safety, Safety. \n\nAdoption of the Amendment \n\tAccordingly, 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:\n\n PART 39 - AIRWORTHINESS DIRECTIVES \n\n\t1. The authority citation for part 39 continues to read as follows: Authority: 49 U.S.C. 106(g), 40113, 44701. § 39.13 (Amended) \n\t2. Section 39.13 is amended by removing amendment 39-9871 (62 FR 15, January 2, 1997), and by adding a new airworthiness directive (AD), amendment 39-11948, to read as follows: