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Proposed Rule

Airworthiness Directives; The Cessna Aircraft Company Model 525 Airplanes

Document Details

Information about this document as published in the Federal Register.

Published Document

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Start Preamble

AGENCY:

Federal Aviation Administration (FAA), DOT.

ACTION:

Notice of proposed rulemaking (NPRM).

SUMMARY:

The FAA proposes to supersede Airworthiness Directive (AD) 2003-21-07, which applies to certain The Cessna Aircraft Company (Cessna) Model 525 airplanes. AD 2003-21-07 currently requires you to disengage the pitch trim circuit breaker and AP servo circuit breaker and then tie strap each of them to prevent them from being engaged. Not utilizing this equipment prevents a single-point failure. This proposed AD is the result of Cessna having now developed and made changes in the design of the affected trim printed circuit board (PCB) assembly to allow the use of the assembly and the prevention of the single-point failure, and identification of additional airplanes that have the same unsafe condition. Consequently, this proposed AD would require you to remove and replace an old trim PCB assembly with a new design assembly or modify an old trim PCB assembly to the new design. We are issuing this proposed AD to correct this single-point failure in the electric pitch trim system, which will result in a runaway pitch trim condition where the pilot could not disconnect using the control wheel autopilot/trim disconnect switch. Failure of the electric trim system would result in a large pitch mistrim and would cause excessive control forces that the pilot could not overcome.

DATES:

We must receive any comments on this proposed AD by April 15, 2004.

ADDRESSES:

Use one of the following to submit comments on this proposed AD:

  • By mail: FAA, Central Region, Office of the Regional Counsel, Attention: Rules Docket No. 2003-CE-54-AD, 901 Locust, Room 506, Kansas City, Missouri 64106.
  • By fax: (816) 329-3771.
  • By e-mail: 9-ACE-7-Docket@faa.gov. Comments sent electronically must contain “Docket No. 2003-CE-54-AD” in the subject line. If you send comments electronically as attached electronic files, the files must be formatted in Microsoft Word 97 for Windows or ASCII.

You may get the service information identified in this proposed AD from The Cessna Aircraft Company, Product Support, P.O. Box 7706, Wichita, Kansas 67277; telephone: (316) 517-6000; facsimile: (316) 517-8500.

You may view the AD docket at FAA, Central Region, Office of the Regional Counsel, Attention: Rules Docket No. 2003-CE-54-AD, 901 Locust, Room 506, Kansas City, Missouri 64106. Office hours are 8 a.m. to 4 p.m., Monday through Friday, except Federal holidays.

Start Further Info

FOR FURTHER INFORMATION CONTACT:

Dan Withers, Aerospace Engineer, Wichita Aircraft Certification Office, FAA, 1801 Airport Road, Wichita, Kansas 67209; telephone: (316) 946-4196; facsimile: (316) 946-4107.

End Further Info End Preamble Start Supplemental Information

SUPPLEMENTARY INFORMATION:

Comments Invited

How do I comment on this proposed AD? We invite you to submit any written relevant data, views, or arguments regarding this proposal. Send your comments to an address listed under ADDRESSES. Include “AD Docket No. 2003-CE-54-AD” in the subject line of your comments. If you want us to acknowledge receipt of your mailed comments, send us a self-addressed, stamped postcard with the docket number written on it. We will date-stamp your postcard and mail it back to you.

Are there any specific portions of this proposed AD I should pay attention to? We specifically invite comments on the overall regulatory, economic, environmental, and energy aspects of this proposed AD. If you contact us through a nonwritten communication and that contact relates to a substantive part of this proposed AD, we will summarize the contact and place the summary in the docket. We will consider all comments received by the closing date and may amend this proposed AD in light of those comments and contacts.

Discussion

Has FAA taken any action to this point? A report of an accident involving a Cessna Model 525 airplane where the pilot reported a problem with the pitch trim system, and later Cessna and FAA analysis that revealed the potential for a single-wire shorting caused us to issue AD 2003-21-07, Amendment 39-13342 (68 FR 60028, October 21, 2003). AD 2003-21-07 currently requires you to do the following on Cessna Model 525 airplanes:

—Disengage the pitch trim circuit breaker and AP servo circuit breaker; and

—Tie strap each of them to prevent them from being engaged.

What has happened since AD 2003-21-07 to initiate this proposed action? AD 2003-21-07 is considered an interim action since compliance corrected the condition where the control wheel autopilot/trim disconnect switch did not stop the runaway condition. However, AD 2003-21-07 did not correct the issue of the single-point failure while still utilizing the desired equipment. Cessna has now developed and made changes in the design of the affected trim printed circuit board (PCB) assembly to eliminate the single-point failure while allowing the use of the equipment, and identified additional airplanes that have the same unsafe condition.

What is the potential impact if FAA took no action? Failure of the electric trim system would result in a large pitch mistrim and would cause excessive Start Printed Page 5757control forces that the pilot could not overcome.

Is there service information that applies to this subject? Cessna has issued Citation Service Bulletin No. SB525-27-17, dated December 9, 2003.

What are the provisions of this service information? The service bulletin includes procedures for:

—Inspecting the electric elevator trim motor;

—Removing the trim PCB assembly;

—Modifying the trim PCB assembly;

—Installing a trim PCB assembly; and

—Removing any tie straps or extension caps installed on the AP servos and pitch trim circuit breakers.

FAA's Determination and Requirements of This Proposed AD

What has FAA decided? We have evaluated all pertinent information and identified an unsafe condition that is likely to exist or develop on other products of this same type design. Therefore, we are proposing AD action.

What would this proposed AD require? This proposed AD would supersede AD 2003-21-07 with a new AD that would require you to:

—Remove any 6518351-3 or 6518351-5 trim PCB assembly and replace with a 6518351-10 (EX) trim PCB assembly; or

—Modify the 6518351-8 trim PCB assembly to a 6518351-10 trim PCB assembly.

How does the revision to 14 CFR part 39 affect this proposed AD? On July 10, 2002, we published a new version of 14 CFR part 39 (67 FR 47997, July 22, 2002), which governs 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 would this proposed AD impact? We estimate that this proposed AD affects 251 airplanes in the U.S. registry.

What would be the cost impact of this proposed AD on owners/operators of the affected airplanes? We estimate the following costs to accomplish this proposed modification of the 6518351-8 trim PCB assembly to a 6518351-10 trim PCB assembly. We have no way of determining the number of airplanes that may need this modification:

Labor costParts costTotal cost per airplane
4 workhours × $65 per hour = $260$2,995.$2,995+$260 = $3,255.

We estimate the following costs to accomplish this proposed replacement of any 6518351-3 or 6518351-5 trim PCB assembly with a 6518351-10 (EX) trim PCB assembly. We have no way of determining the number of airplanes that may need this replacement:

Labor costParts costTotal cost per airplane
2 workhours × $65 per hour = $130$2,995.$2,995+$130 = $3,125.

What is the difference between the cost impact of this proposed AD and the cost impact of AD 2003-21-07? The estimated cost impact of AD 2003-21-07 on each of 116 airplanes in the U.S. registry is $65. This is to disengage the pitch trim circuit breaker and AP servo circuit breaker and then tie strap each of them to prevent them from being engaged.

The estimated cost of this proposed AD is $3,125 or $3,255 on each of 251 airplanes in the U.S. registry to do the replacement or modification of the trim PCB assembly.

Compliance Time of This Proposed AD

What would be the compliance time of this proposed AD? The compliance time of this proposed AD is within the next 24 calendar months after the effective date of this AD or within 300 hours time-in-service (TIS) after the effective date of this AD, whichever occurs first.

Why is the compliance time of this proposed AD presented in both hours TIS and calendar time? A single-wire shorting to 28 volts or a failure of a relay that results in the relay contacts remaining closed is a direct result of airplane operation. For example, either failure could occur on an affected airplane within a short period of airplane operation while you could operate another affected airplane for a considerable amount of time without experiencing either failure. Therefore, to assure that either failure is detected and corrected in a timely manner without inadvertently grounding any of the affected airplanes, we are using a compliance time based upon both hours TIS and calendar time.

Regulatory Findings

Would this proposed AD impact various entities? We have determined that this proposed AD would not have federalism implications under Executive Order 13132. This proposed AD would 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.

Would this proposed AD involve a significant rule or regulatory action? For the reasons discussed above, I certify that this proposed 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 proposed 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-54-AD” in your request.

Start List of Subjects

List of Subjects in 14 CFR Part 39

End List of Subjects

The Proposed Amendment

Accordingly, under the authority delegated to me by the Administrator, the Federal Aviation Administration proposes to amend 14 CFR part 39 as follows:

Start Part

PART 39—AIRWORTHINESS DIRECTIVES

1. The authority citation for part 39 continues to read as follows:

Start Authority

Start Printed Page 5758 Authority: 49 U.S.C. 106(g), 40113, 44701.

End Authority
[Amended]

2. The FAA amends § 39.13 by removing Airworthiness Directive (AD) 2003-21-07, Amendment 39-13342 (68 FR 60028, October 21, 2003), and by adding a new AD to read as follows:

The Cessna Aircraft Company: Docket No. 2003-CE-54-AD

When Is the Last Date I Can Submit Comments on This Proposed AD?

(a) We must receive comments on this proposed airworthiness directive (AD) by April 15, 2004.

What Other ADs Are Affected by This Action?

(b) This AD supersedes AD 2003-21-07.

What Airplanes Are Affected by This AD?

(c) This AD affects Model 525 airplanes with the following serial numbers that are certificated in any category:

(1) Group 1 (maintains the actions from AD 2003-21-07): 525-0001, 525-0002, and 525-0004 through 525-0159.

(2) Group 2: 525-0160 through 525-0359.

What Is the Unsafe Condition Presented in This AD?

(d) This AD is the result of Cessna having now developed and made changes in the design of the affected trim printed circuit board (PCB) assembly to allow the use of the assembly and the prevention of the single-point failure, and identification of additional airplanes that have the same unsafe condition. The actions specified in this AD are intended to correct this single-point failure in the electric pitch trim system, which will result in a runaway pitch trim condition where the pilot could not disconnect using the control wheel autopilot/trim disconnect switch. Failure of the electric trim system would result in a large pitch mistrim and would cause excessive control forces that the pilot could not overcome.

What Must I Do To Address This Problem?

(e) To address this problem, you must do the following:

ActionsComplianceProcedures
(1) For Group 1 airplanes only: Disengage the PITCH TRIM circuit breaker located on the left circuit breaker panel. Install a tie strap (part number (P/N) MS3367-1-4 or equivalent part number) on the shaft of the PITCH TRIM circuit breaker from being engaged.Within 5 calendar days or 10 hours time-in-service after October 22, 2003 (the effective date of AD 2003-21-07), whichever occurs first.Not Applicable.
(2) For Group 1 airplanes only: Disengage the AP SERVOS circuit breaker located in the right circuit breaker panel. Install a tie strap (P/N MS3367-1-4 or equivalent part number) on the shaft of the AP SERVOS circuit breaker to prevent the circuit breaker from being engaged.Within 5 calendar days or 10 hours time-in-service after October 22, 2003 (the effective date of AD 2003-21-07), whichever occurs first.Not Applicable.
(3) The Minimum Crew portion of Section II—Operating Limitations of the Airplane Flight Manual (AFM) provides information on applicable operating limitations with the autopilot inoperable.Not Applicable.Not Applicable.
(4) All affected airplanes were originally equipped with a P/N 6518351-3 or P/N 65138351-5 Trim PC Board Assembly. If a P/N 6518351-8 Trim PC Board Assembly is installed, contact the Wichita Aircraft Certification Office at the address in paragraph (f) of this AD to determine if the installed P/N 6518351-8 Trim PC board assembly is an alternative method of compliance to this AD.Not Applicable.Not Applicable.
(5) Cessna Citation Alert Service Letter ASL525-27-02, dated October 10, 2003, contains information related to this subject.Not Applicable.Not Applicable.
(6) For both Group 1 and Group 2 airplanes: Do the trim PCB assembly change as follows: (i) Modify the 6518351-8 trim PCB assembly to a 6518351-10 trim PCB assembly; or (ii) Replace any 6518351-3 trim PCB assembly with 6518351-10 (EX) trim PCB assembly.Within the next 24 calendar months after the effective date of this AD or within 300 hours time-in-service (TIS) after the effective date of this AD, whichever occurs first, unless already done.Follow the ACCOMPLISHMENT INSTRUCTIONS paragraph of Cessna Citation Service Bulletin No. SB525-27-17, dated December 9, 2003.
(7) For both Group 1 and Group airplanes: Remove any tie strap (P/N MS3367-1-4 or equivalent part number) on the AP SERVOS and PITCH circuit breakers. (Required by AD 2003-21-07.)Before further flight after the modification or replacement of the trim PCB assembly required by paragraph (e)(6)(i) or (e)(6)(ii) of this AD.Follow the ACCOMPLISHMENT INSTRUCTIONS paragraph of Cessna Citation Service Bulletin No. SB525-27-17, dated December 9, 2003.
(8) For both Group 1 and Group 2 airplanes: Do not install any 6518351-8, 6518351-3, or 6518351-5 trim PCB assembly.As of the effective date of this AD.Not Applicable.

May I Request an Alternative Method of Compliance?

(f) You may request a different method of compliance or a different compliance time for this AD by following the procedures in 14 CFR 39.19. Unless FAA authorizes otherwise, send your request to your principal inspector. The principal inspector may add comments and will send your request to the Manager, Wichita Aircraft Certification Office (ACO), FAA.

(1) For information on any already approved alternative methods of compliance, contact Dan Withers, Aerospace Engineer, Wichita ACO, FAA, 1801 Airport Road, Wichita, Kansas 67209; telephone: (316) 946-4196; facsimile: (316) 946-4107.

(2) Alternative methods of compliance approved for AD 2003-21-07 are not Start Printed Page 5759approved as alternative methods of compliance for this AD.

May I Get Copies of the Documents Referenced in This AD?

(g) You may get copies of the documents referenced in this AD from The Cessna Aircraft Company, Product Support, P.O. Box 7706, Wichita, Kansas 67277; telephone: (316) 517-6000; facsimile: (316) 517-8500. You may view these documents at FAA, Central Region, Office of the Regional Counsel, 901 Locust, Room 506, Kansas City, Missouri 64106.

Start Signature

Issued in Kansas City, Missouri, on January 29, 2004.

Dorenda D. Baker,

Manager, Small Airplane Directorate, Aircraft Certification Service.

End Signature End Part End Supplemental Information

[FR Doc. 04-2403 Filed 2-5-04; 8:45 am]

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