03-28166. Airworthiness Directives; Cessna Model 560 Airplanes

AGENCY:

Federal Aviation Administration, DOT.

ACTION:

Final rule; request for comments.

SUMMARY:

This amendment adopts a new airworthiness directive (AD) that is applicable to certain Cessna Model 560 airplanes. This action requires disengaging and tie-strapping the pitch trim and autopilot servo (servo 1) circuit breakers. This action also provides an optional inspection and follow-on actions that, if accomplished, terminates the requirement to disengage and tie-strap those circuit breakers. This action is necessary to prevent a single-point failure in the trim system from causing a runaway trim condition that the pilot may be unable to stop by using the autopilot-disconnect switch. This condition could result in loss of control of the airplane. This action is intended to address the identified unsafe condition.

DATES:

Effective November 28, 2003.

The incorporation by reference of certain publications listed in the regulations is approved by the Director of the Federal Register as of November 28, 2003.

Comments for inclusion in the Rules Docket must be received on or before January 12, 2004.

ADDRESSES:

Submit comments in triplicate to the Federal Aviation Administration (FAA), Transport Airplane Directorate, ANM-114, Attention: Rules Docket No. 2003-NM-225-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056. Comments may be inspected at this location between 9 a.m. and 3 p.m., Monday through Friday, except Federal holidays. Comments may be submitted via fax to [phone]. Comments may also be sent via the Internet using the following address: [e-mail]. Comments sent via fax or the Internet must contain “Docket No. 2003-NM-225-AD” in the subject line and need not be submitted in triplicate. Comments sent via the Internet as attached electronic files must be formatted in Microsoft Word 97 or 2000 or ASCII text.

The service information referenced in this AD may be obtained from Cessna Aircraft Co., P.O. Box 7706, Wichita, Kansas 67277. This information may be examined at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; at the FAA, Wichita Aircraft Certification Office, 1801 Airport Road, Room 100, Mid-Continent Airport, Wichita, Kansas; or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC.

FOR FURTHER INFORMATION CONTACT:

Bryan Easterwood, Aerospace Engineer, Systems and Equipment Branch, ACE-116W, FAA, Wichita Aircraft Certification Office, 1801 Airport Road, Room 100, Mid-Continent Airport, Wichita, Kansas 67209; telephone [phone]; fax [phone].

SUPPLEMENTARY INFORMATION:

The FAA has received a report of an accident involving a Cessna Model 525 airplane. The pilot reported a problem with the trim system and was forced to ditch the airplane in the water near Coupeville, Washington. Although the final investigation by the National Transportation Safety Board is not complete, investigation revealed a discrepancy that could allow single-wire shorting to 28 volts or the failure of a relay in the trim system such that the relay contacts remain closed. In addition, the pilot may be unable to stop the runaway trim condition by pressing the red autopilot-disconnect switch located on the control wheel, due to the design of the trim system on a certain serial number range of airplanes. A runaway trim condition that the pilot is unable to stop by using the autopilot-disconnect switch could result in loss of control of the airplane.

The design of the trim system on certain Cessna Model 560 airplanes is the same as that on certain Cessna Model 525 airplanes. Therefore, Model 560 airplanes may be subject to the same unsafe condition.

Explanation of Relevant Service Information

We have reviewed and approved Cessna Alert Service Letter ASL560-27-10, dated October 10, 2003. Among other actions, that service letter describes procedures for disengaging the pitch trim and autopilot (AP) servo (servo 1) circuit breakers and tie-strapping those circuit breakers so that they may not be engaged. Accomplishment of these actions specified in the service letter is intended to adequately address the identified unsafe condition.

Cessna Alert Service Letter ASL560-27-10 also describes procedures for an inspection to determine the part number of the installed trim pc board assembly, and follow-on actions. The follow-on actions include replacement of the assembly with an improved assembly and installation of an extension cap on the pitch trim circuit breaker, as applicable. Once the inspection and applicable follow-on actions have been accomplished, the tie straps on the pitch trim and AP servo circuit breakers may be removed and those circuit breakers may be re-engaged.

Explanation of the Requirements of the Rule

Since an unsafe condition has been identified that is likely to exist or develop on other airplanes of the same type design registered in the United States, this AD requires disengaging and tie-strapping the pitch trim and AP servo circuit breakers. This AD also provides for an optional inspection and follow-on actions that terminates the requirement for disengaging and tie-strapping those circuit breakers. These actions must be accomplished per the service letter described previously, except as discussed below.

Differences Between This AD and Service Letter

Although the service letter requires that the disengaging and tie-strapping of the pitch trim and AP servo circuit breakers be accomplished upon receipt of the service letter, this AD allows accomplishment of these actions within 5 days or 10 hours time-in-service after the effective date of this AD, whichever is first. We find that such a compliance time represents an appropriate compliance time for affected airplanes to continue to operate without compromising safety.

Although the service letter is effective for certain Model 560 airplanes having serial numbers 0260 through 0538 inclusive, this AD is applicable to certain Model 560 airplanes having serial numbers 0260 through 0396 inclusive. While the discrepancy that could allow a single-point failure in the trim system, causing a runaway trim condition, may occur on any airplane having a serial number in the range 0260 through 0538 inclusive, on airplanes having serial numbers 0397 through 0538 inclusive, the pilot would be able to stop the runaway trim condition by pressing the red autopilot-disconnect switch located on the control wheel. Therefore, we have determined that an acceptable level of safety exists on airplanes having serial numbers 0397 through 0538 inclusive, and it is not necessary to require disengaging and tie-strapping of the pitch trim and AP servo circuit breakers on these airplanes at this time.

Although the Accomplishment Instructions of the service letter describe procedures for sending a maintenance transaction report to the manufacturer, this AD does not require this action.

Interim Action

We consider this proposed AD interim action. We are currently considering requiring the optional terminating action provided in this AD—inspection of the trim pc board assembly and follow-on actions, which would eliminate the need for the tie straps on the pitch trim and AP servo circuit breakers, and would allow those circuit breakers to be re-engaged. However, the planned compliance time for such actions would likely allow enough time to provide notice and opportunity for prior public comment on the merits of those actions.

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 less than 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 2003-NM-225-AD.” The postcard will be date stamped and returned to the commenter.

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.

§ 39.13

[Amended]

2. Section 39.13 is amended by adding the following new airworthiness directive:

2003-23-02 Cessna Aircraft Company: Amendment 39-13365. Docket 2003-NM-225-AD.

Applicability: Model 560 airplanes, having serial numbers 0260 through 0396 inclusive, certificated in any category; except those on which Cessna Service Bulletin 560-34-93, dated March 16, 2001, has been accomplished.

Compliance: Required as indicated, unless accomplished previously.

To prevent a single-point failure in the trim system from causing a runaway trim condition that the pilot may be unable to stop by using the autopilot disconnect switch, which could result in loss of control of the airplane, accomplish the following:

Disengaging and Tie-Strapping Circuit Breakers

(a) Within 5 days or 10 hours time-in-service after the effective date of this AD, whichever is first: Disengage the PITCH TRIM circuit breaker on the left circuit breaker panel and the SERVO 1 circuit breaker on the right circuit breaker panel, and install tie straps on those circuit breakers, per paragraphs 1.A. and 1.B. of the Accomplishment Instructions of Cessna Alert Service Letter ASL560-27-10, dated October 10, 2003.

Optional Inspection and Corrective Actions

(b) Accomplishment of the inspection of the trim pc board assembly to determine the part number of the assembly and all applicable follow-on actions; per paragraphs 2.A., 2.B., and 2.C. of the Accomplishment Instructions of Cessna Alert Service Letter ASL560-27-10, dated October 10, 2003; terminates the requirements of paragraph (a) of this AD. Once the inspection and applicable follow-on actions have been accomplished, the tie straps on the pitch trim and autopilot servo circuit breakers may be removed and those circuit breakers may be re-engaged.

Parts Installation

(c) As of the effective date of this AD, no person may install a trim pc board assembly having part number 6518351-3 or -5 on any airplane.

Alternative Methods of Compliance

(d) In accordance with 14 CFR 39.19, the Manager, Wichita Aircraft Certification Office (ACO), FAA, is authorized to approve alternative methods of compliance for this AD.

Incorporation by Reference

(e) The actions shall be done in accordance with Cessna Alert Service Letter ASL560-27-10, dated October 10, 2003. This incorporation by reference was approved by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies may be obtained from Cessna Aircraft Co., P.O. Box 7706, Wichita, Kansas 67277. Copies may be inspected at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; at the FAA, Wichita Aircraft Certification Office, 1801 Airport Road, Room 100, Mid-Continent Airport, Wichita, Kansas; or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC.

Effective Date

(f) This amendment becomes effective on November 28, 2003.

Issued in Renton, Washington, on November 4, 2003.

Ali Bahrami,

Acting Manager, Transport Airplane Directorate, Aircraft Certification Service.