Discussion \n\n\tWe have received reports (including two in January 2010) of rejected takeoffs at speeds above takeoff decision speed following inadvertent engagement of the autopilot on the ground. Since 1995, there have been nine reported instances of a rejected takeoff because of higher than normal control column forces at takeoff rotation due to the pilot inadvertently engaging the autopilot in lower-speed takeoff roll. When the flightcrew inadvertently engages the autopilot on ground during the lower-speed phase of the takeoff roll, the control column forces will be higher than normal when the pilot attempts to initiate the takeoff rotation. This condition, if not corrected, could result in rejected takeoff at rotation speed, and consequent possible overrun of the runway. \n\tThe Boeing Company has also discovered during flight simulations that the climb gradient is less than optimal for obstacle clearance during a one-engine takeoff (performance-limited) situation. This is caused by an error in the pitch command law of the autopilot flight director computer (AFDC). This condition, if not corrected, could result in a lower-than-optimal climb gradient during takeoff, and consequent failure to clear obstacles on the ground during a performance-limited takeoff. \n\nRelevant Service Information \n\n\tWe reviewed Boeing Alert Service Bulletin 777-22A0024, dated January 22, 2010. The alert service bulletin describes procedures for installing new operational program software for the left, center, and right AFDCs. The new software will disengage the autopilot whenever the flaps are extended and the airplane is on the ground and not in rollout mode. Autopilot engagement is inhibited when the flaps are extended and the airplane is on the ground or below 50 feet above ground level. The new software also maintains the initial engine-out (performance- limited) takeoff pitch target for a longer duration to minimize altitude loss during the takeoff, and targets a velocity to maximize climbout performance. \n\nFAA's Determination and Requirements of This AD \n\n\tWe are issuing this AD because we evaluated all the relevant information and determined the unsafe conditions described previously are likely to exist or develop in other products of these same type designs. This AD requires accomplishing the actions specified in the service information described previously, except as discussed under "Differences Between the AD and the Service Information.'' \n\nDifferences Between the AD and the Service Information \n\n\tAlthough Boeing Alert Service Bulletin 777-22A0024, dated January 22, 2010, recommends accomplishing the operational program software installation "within 12 months after the original issue date of this service bulletin,'' we have determined that this compliance time would not address the identified unsafe conditions in a timely manner. In developing an appropriate compliance time for this AD, we considered not only the manufacturer's recommendation, 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 operational program software installation. In light of all of these factors, we find a compliance time of 90 days after the effective date of this AD for completing the required actions to be warranted, in that it represents an appropriate interval of time for affected airplanes to continue to operate without compromising safety. This difference has been coordinated with The Boeing Company. \n\nFAA's Justification and Determination of the Effective Date \n\n\tA rejected takeoff at rotation speed significantly increases the risk of a runway overrun, and a lower-than-optimal climb gradient during a performance-limited takeoff drastically increases the risk of failure of the airplane to clear obstacles on the ground during the initial climb phase after takeoff. Both of these conditions can result in fatal injury to flightcrew, passengers, and people on the ground, as well as extensive damage to the airplane and property on the ground. Because of our requirement to promote safe flight of civil aircraft and thus the critical need to ensure the proper functioning of the autopilot flight director system, in addition to the two recent reports and the short compliance time involved with this action, this AD must be issued immediately. \n\tBecause an unsafe condition exists that requires the immediate adoption of this AD, we find 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. \n\nComments Invited \n\n\tThis AD is a final rule that involves requirements affecting flight safety, and we did not provide you with notice and an opportunity to provide your comments before it becomes effective. However, we invite you to send any written data, views, or arguments about this AD. Send your comments to an address listed under the ADDRESSES section. Include "Docket No. FAA-2010-0221; Directorate Identifier 2010-NM-043-AD'' at the beginning of your comments. We specifically invite comments on the overall regulatory, economic, environmental, and energy aspects of this AD. We will consider all comments received by the closing date and may amend this AD because of those comments. \n\tWe will post all comments we receive, without change, to http:// www.regulations.gov, including any personal information you provide. We will also post a report summarizing each substantive verbal contact we receive about this AD. \n\nAuthority for This Rulemaking \n\n\tTitle 49 of the United States Code specifies the FAA's authority to issue rules on aviation safety. Subtitle I, section 106, describes the authority of the FAA Administrator. "Subtitle VII: Aviation Programs,'' describes in more detail the scope of the Agency's authority. \n\tWe are issuing this rulemaking under the authoritydescribed in "Subtitle VII, Part A, Subpart III, Section 44701: General requirements.'' Under that section, Congress charges the FAA with promoting safe flight of civil aircraft in air commerce by prescribing regulations for practices, methods, and procedures the Administrator finds necessary for safety in air commerce. This regulation is within the scope of that authority because it addresses an unsafe condition that is likely to exist or develop on products identified in this rulemaking action. \n\nRegulatory Findings \n\n\tThis AD will not have federalism implications under Executive Order 13132. This AD 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. \n\tFor the reasons discussed above, I certify that this AD: \n\t(1) Is not a "significant regulatory action'' under Executive Order 12866, \n\t(2) Is not a "significantrule'' under DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979), and \n\t(3) Will not have a significant economic impact, positive or negative, on a substantial number of small entities under the criteria of the Regulatory Flexibility Act. \n\tYou can find our regulatory evaluation and the estimated costs of compliance in the AD Docket. \n\nList of Subjects in 14 CFR Part 39 \n\n\tAir transportation, Aircraft, Aviation safety, Incorporation by reference, Safety. \n\nAdoption of the Amendment \n\nAccordingly, under the authority delegated to me by the Administrator, the FAA amends 14 CFR part 39 as follows: \n\nPART 39--AIRWORTHINESS DIRECTIVES \n\n1. The authority citation for part 39 continues to read as follows: \n\n\tAuthority: 49 U.S.C. 106(g), 40113, 44701. \n\nSec. 39.13 (Amended) \n\n2. The FAA amends Sec. 39.13 by adding the following new AD: