Discussion
What events have caused this AD? The Federal Office for Civil Aviation (FOCA), which is the airworthiness authority for Switzerland, recently notified FAA that an unsafe condition may exist on certain Pilatus Models PC-12 and PC-12/45 airplanes. The FOCA reports that an abrupt nose down pitch condition occurred on a PC-12 airplane.
Investigation revealed that the pilot disconnected the autopilot when the flaps were at a 40-degree selection.
Pilatus has determined that the pitch actuator sense circuitry becomes over-active during a 40-degree flight phase. Therefore, Pilatus designed a new pitch actuator that modifies sense output signals and removes the flap in motion signal to the autopilot.
What is the potential impact if FAA took no action? This condition, if not corrected, could result in an out-of-trim condition when the flaps are at a 40-degree flight phase and the pilot disconnects the autopilot. This condition could lead to reduced ability to control the airplane.
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 Pilatus Models PC-12 and PC- 12/45 airplanes. This proposal was published in the Federal Register as a notice of proposed rulemaking (NPRM) on April 13, 2005 (70 FR 19342). The NPRM proposed to require you to insert the temporary revision into the Limitations Section of the Pilot Operating Handbook (POH). The NPRM also proposed to require you to replace the pitch actuator with an improved design pitch actuator and make the necessary wiring and circuit breaker changes, as applicable. Installing the improved design pitch actuator would terminate the need for the temporary revision in the POH.
Comments
Was the public invited to comment? We provided the public the opportunity to participate in developing this AD. The following presents the comments received on the proposal and FAA's response to each comment:
Comment Issue: Change the Compliance Time for Replacing the Pitch Actuator
What is the commenter's concern? Two commenters state the requirement to replace the pitch actuator within 6 months after the effective date of the AD may place an unnecessary burden on both the operators and service centers.
The Pilatus PC-12 fleet consists of over 500 airplanes worldwide. Because of material quantity constraints, the logistics associated with replacing the pitch actuator within six months would be nearly impossible for all operators.
Extensive flight-testing identified the unsafe condition associated with operation of the autopilot with 40-degree flaps.
The AD requires inserting a temporary revision into the Pilot Operating Handbook (POH) prohibiting the use of the autopilot with the flaps at the 40-degree position, which removes the risk of a major out of trim condition.
The commenters request the compliance time for replacing the pitch actuator be changed from "Within the next 6 months after the effective date of this AD, unless already done," to "Before December 31, 2006."
What is FAA's response to the concern? We partially agree with the commenters.
Since it has been identified through flight-testing that the unsafe condition can be avoided by inserting Temporary Revision No. 11 or No. 40 into the Limitation Section of the POH, we agree to extend the compliance time for replacing the pitch actuator.
Extending the compliance time will allow the owners/operators more time to get the pitch actuator replaced and allows the supplier to meet the demand for parts in a timely manner. However, we rarely use a specific calendar date to express compliance time and only then when engineering analysis establishes a direct relationship between the date and either the compliance "threshold" or the "grace period."
Basically, the commenters are requesting an additional 12 months to replace the pitch actuator.
Therefore, we will change the final rule AD action and increase the compliance time for replacing the pitch actuator to "Within the next 18 months after the effective date of this AD, unless already done."
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 theFAA'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 330 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 incorporate the Pilot Operating Handbook (POH) Temporary Revision:
Labor cost
Parts cost
Total cost per Airplane
Total cost on U.S. operators
1 work hour $65 per hour = $65.
Not applicable
$65
$21,450
Pilatus will provide warranty credit for replacing the pitch actuator to the extent stated in the service information.
Authority for This Rulemaking
What authority does FAA have for issuing thisrulemaking action? Title 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.
We are issuing this rulemaking under the authority described 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 AD.
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 other information as included in the Regulatory Evaluation) 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 "Docket No.FAA-2005-20720; Directorate Identifier 2005-CE-17-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.
Sec. 39.13 [Amended]
2. FAA amends Sec. 39.13 by adding a new AD to read as follows: