Discussion
What events have caused this AD? We have received reports of an unsafe condition on certain Cessna Models 172R, 172S, 182S, 182T, T182T, 206H, and T206H airplanes that are equipped with a Honeywell KAP 140 autopilot computer system.
The KAP 140 autopilot computer system is located on the lower portion of the center instrument control panel near the throttle on these Cessna airplanes. Because of this location on the instrument control panel of the affected Cessna airplanes, the Autopilot Engage (AP) button could unintentionally be depressed when the pilot pushes the throttle knob forward. The pilot could also unintentionally engage the autopilot system by inadvertently bumping the Heading (HDG) button, Altitude (ALT) mode-select button, or Autopilot Engage (AP) button on the KAP 140 computer. Unless intentionally engaged, the pilot does not know that the autopilot system is engaged.
The Honeywell KAP 140 autopilot computer systemis also installed in the New Piper, Inc. Model PA-28-181 airplanes. This AD does not affect these airplanes because of the location of the equipment. The equipment is installed on the center instrument panel near the throttle on the affected airplanes, but is installed in the upper half of the instrument control panel on the Piper airplanes. The unsafe condition only exists on the Cessna airplanes.
Honeywell has updated the operating software for the KAP 140 autopilot computer system, which will now only allow the AP button on the instrument control panel to engage the autopilot system. This update also adds two voice messages if auto trim operation is detected, lengthens the amount of time that the autopilot button must be depressed in order for it to engage, and changes how the flight control display shows that the AP has been engaged.
What is the potential impact if FAA took no action? If not corrected, inadvertent and undetected engagement of the autopilot system could cause the pilot to take inappropriate actions.
Has FAA taken any action to this point? We issued a proposal to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) to include an AD that would apply to certain Cessna Models 172R, 172S, 182S, 182T, T182T, 206H, and T206H airplanes that are equipped with a Honeywell KAP 140 autopilot computer system installed on the center instrument control panel near the throttle. This proposal was published in the Federal Register as a notice of proposed rulemaking (NPRM) on July 29, 2003 (68 FR 44497). The NPRM proposed to require you to:
--Install an update to the autopilot computer system operating software;
--Change the unit part number;
--Place an M tag on the unit serial number tag; and
--Change the unit's software modification tag.
Comments
Was the public invited to comment? We provided the public the opportunity to participate in the development of this AD. The following presents the comments received on theproposal and FAA's response to each comment:
Comment Issue: AD Action Is Not Necessary
What is the commenter's concern? Three commenters state that they do not think AD action is necessary to address the proposed unsafe condition; however, one commenter agrees with the change to the KC 140 autopilot computer system operating software.
The other commenters state that appropriate pilot recognition and response could easily resolve the problem. One commenter states that an attentive pilot would know if the autopilot has been unintentionally engaged. The commenter gives examples of circumstances that should alert the pilot that the autopilot has been engaged:
--There is significant resistance in the controls;
--The mode of operation (i.e., ROL, HDG, etc.) is immediately displayed on the face of the autopilot; and
--The pitch trim wheel never moves on its own; therefore, if the autopilot is engaged and the pilot is trying to make a change in pitch manually, the autopilot will resist this change and the pitch trim wheel will move.
The commenter states that because there are multiple indications that the KAP 140 autopilot is engaged, the proposed AD is not necessary.
We infer that the commenters want us to withdraw the NPRM.
What is FAA's response to the concern? We do not agree with that we should withdraw the NPRM. We agree that the autopilot computer system operating software should be updated. The changes to the KC 140 autopilot computer system operating software required by this AD will greatly limit the ability of the pilot to unintentionally engage the autopilot. The changes will also provide additional indications to the pilot that the autopilot has been engaged.
Because we continue to receive reports of related accidents involving pilots with experience ranging from novice to certified flight instructors, it is an indication that it is not obvious to all pilots that the autopilot is engaged. We do not agree that we could resolve the problem through appropriate pilot recognition and response.
We are not changing the final rule AD based on these comments.
Conclusion
What is FAA's final determination on this issue? We have carefully reviewed the available data and determined that air safety and the public interest require adopting the AD as proposed except for the changes discussed above and minor editorial corrections. We have determined that these changes and minor corrections:
--Are consistent with the intent that was proposed in the NPRM for correcting the unsafe condition; and
--Do not add any additional burden upon the public than was already proposed in the NPRM.
Changes to 14 CFR Part 39--Effect on the AD
How does the revision to 14 CFR part 39 affect this AD? On July 10, 2002, the FAA published a new version of 14 CFR part 39 (67 FR 47997, July 22, 2002), which governs the FAA's AD system. This regulation now includes material that relates to altered products, special flight permits, and alternative methods of compliance. This material previously was included in each individual AD. Since this material is included in 14 CFR part 39, we will not include it in future AD actions.
Costs of Compliance
How many airplanes does this AD impact? We estimate that this AD affects 3,681 airplanes in the U.S. registry.
What is the cost impact of this AD on owners/operators of the affected airplanes? We estimate the following costs to accomplish the modification:
Labor cost
Parts cost
Total cost per
airplane
Total cost on U.S.
operators
7 workhours x $65 per hour
= $455
Not applicable
$455
7 workhours x $65 per hour
= $455
Not all Cessna Models 172R, 172S, 182S, 182T, T182T, 206H, and T206H airplanes on the U.S. registry have a KAP 140 autopilot computer system installed.
Honeywell will provide warranty credit for labor and parts to the extent noted under WARRANTY INFORMATION in Honeywell Service Bulletin No: KC 140-M1, dated August 2002.
Regulatory Findings
Will this AD impact various entities? We have determined that this 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.
Will this AD involve a significant rule or regulatory action? For the reasons discussed above, I certify that this AD:
1. Is not a "significant regulatory action" under Executive Order 12866;
2. Is not a "significant rule" under the DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); and
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.
We prepared a summary of the costs to comply with this AD and placed it in the AD Docket. You may get a copy of this summary by sending a request to us at the address listed under ADDRESSES. Include "AD Docket No. 2003-CE-28-AD" in your request.
List of Subjects in 14 CFR Part 39
Air transportation, Aircraft, Aviation safety, Incorporation by reference, Safety.
Adoption of the Amendment
Accordingly, under 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. FAA amends 39.13 by adding a new AD to read as follows: