AD 2003-21-07

Historical

Airworthiness directive · Pitch trim circuit breaker · 525

Effective
October 22, 2003
Published
October 21, 2003 · 68 FR 60028–60030
Issued
October 10, 2003
Superseded by
AD2004-14-20
Model
525
Data sheet
TCDSA1WI
Registered aircraft
670 matched by model
Product
Aircraft · Small airplane
Amendment
39-13342
Docket
2003-CE-46-AD
Issued as
Final rule; request for comments

Unofficial copy from the Federal Register XML, document 03-26276. Only the govinfo PDF is the legal edition. DRS record last changed August 7, 2025.

On this page

Summary

The FAA is adopting a new airworthiness directive (AD) for certain The Cessna Aircraft Company (Cessna) Model 525 airplanes. This AD 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. This AD is the result of analysis that reveals the potential for a single-wire shorting to 28 volts or a failure of a relay in the electric pitch trim system such that the relay contacts remain closed. We are issuing this 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.

The airworthiness directive

2003-21-07 The Cessna Aircraft Company: Amendment 39-13342; Docket No. 2003-CE-46-AD.

(a) When Does This AD Become Effective?

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(a) This AD becomes effective on October 22, 2003.

(b) Are Any Other ADs Affected by This Action?

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(b) None.

(c) What Airplanes Are Affected by This AD?

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(c) This AD affects Model 525 airplanes, serial numbers 525-0001, 525-0002, and 525-0004 through 525-0159, that are certificated in any category.

(d) What Is the Unsafe Condition Presented in This AD?

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(d) This AD is the result of analysis that reveals the potential for a single-wire shorting to 28 volts or a failure of a relay in the electric pitch trim system such that the relay contacts remain closed. We are issuing this 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.

(e) What Must I Do To Address This Problem?

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

ActionsCompliance
(1) 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 to prevent the circuit breaker from being engagedWithin 5 calendar days or 10 hours time-in-service after October 22, 2003 (the effective date of this AD), whichever occurs first.
(2) 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 engagedWithin 5 calendar days or 10 hours time-in-service after October 22, 2003 (the effective date of this AD), whichever occurs first.
(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 inoperableNot 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 ADNot Applicable.
(5) Cessna Citation Alert Service Letter ASL525-27-02, dated October 10, 2003, contains information related to this subjectNot Applicable.

(f) What About Alternative Methods of Compliance?

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(f) You may request a different method of compliance or a different compliance time for this AD by following the procedures in 14 CFR 39.13. Send your request to the Manager, Wichita Aircraft Certification Office (ACO), FAA. For information on any already approved alternative methods of compliance, contact Dan Withers, Aerospace Engineer, FAA, Wichita ACO, 1801 Airport Road, Room 100, Wichita, Kansas 67209, telephone: (316) 946-4196; facsimile: (316) 946-4107.

(g) How Do I Get Copies of the Documents Referenced in This AD?

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(g) You may get copies of the document 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 this document at FAA, Central Region, Office of the Regional Counsel, 901 Locust, Room 506, Kansas City, Missouri 64106.

Rule preamble

The FAA’s background, reasoning and cost estimate, published with the AD.

DatesPage 1

This AD becomes effective on October 22, 2003.

The Director of the Federal Register approved the incorporation by reference of certain publications listed in the regulation as of October 22, 2003.

We must receive any comments on this AD by December 15, 2003.

AddressesPage 1

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

• By mail: FAA, Central Region, Office of the Regional Counsel, Attention: Rules Docket No. 2003-CE-46-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-46-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 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-46-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.

For further information contactPage 1

Dan Withers, Aerospace Engineer, FAA, Wichita Aircraft Certification Office, 1801 Airport Road, Room 100, Wichita, Kansas 67209, telephone: (316) 946-4196; facsimile: (316) 946-4107.

Supplementary informationPage 1

What events have caused this AD? The FAA has received a report of an accident involving a Cessna Model 525 airplane where the pilot ditched the airplane in the water off the coast near Coupeville, Washington. The pilot reported a problem with the pitch trim system.

Although the final investigation by the National Transportation Safety Board (NTSB) is not complete, Cessna and FAA analysis reveals the potential for a single-wire shorting to 28 volts or a failure of a relay in the electric pitch trim system such that the relay contacts remain closed and also precludes disconnect of the pitch trim using the control wheel autopilot/trim disconnect switch.

What are the consequences if the condition is not corrected? 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.

Is there service information that applies to this subject? Cessna has issued Citation Alert Service Letter ASL525-27-02, dated October 10, 2003.

What are the provisions of this service information? The service bulletin includes (as well as other information) procedures for disengaging and tie strapping the pitch trim and autopilot servo circuit breakers.

FAA's Determination and Requirements of the ADPage 1

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.

Since the unsafe condition described previously is likely to exist or develop on other Cessna Model 525 airplanes of the same type design, this AD is being issued to correct a single-point failure in the pitch trim system, which could result in a runaway pitch trim condition where that 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 does this AD require? This AD 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.

In preparation of this rule, we contacted type clubs and aircraft operators to obtain technical information and information on operational and economic impacts. We did not receive any information through these contacts. If received, we would have included, in the rulemaking docket, a discussion of any information that may have influenced this action.

How does the revision to 14 CFR part 39 affect this 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.

Compliance Time of This ADPage 1

What would be the compliance time of this AD? The compliance time of this AD is within 5 days or 10 hours time-in-service after October 22, 2003 (the effective date of this AD), whichever occurs first.

Why is the compliance time of this AD presented in both hours TIS and calendar time? The unsafe condition on these airplanes is not a result of the number of times the airplane is operated. The FAA is establishing the compliance time in both hours TIS and calendar time (with the prevalent being that which occurs first).

This would assure that the unsafe condition is addressed on both high- usage and low-usage airplanes within a reasonable time period without inadvertently grounding any of the affected airplanes.

Comments invitedPage 2

Will I have the opportunity to comment prior to the issuance of the rule? This AD is a final rule that involves requirements affecting flight safety and was not preceded by notice and an opportunity for public comment; however, we invite you to submit any written relevant data, views, or arguments regarding this AD. Send your comments to an address listed under ADDRESSES. Include “AD Docket No. 2003-CE-46-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. We specifically invite comments on the overall regulatory, economic, environmental, and energy aspects of the rule that might suggest a need to modify it. If a person contacts us through a nonwritten communication, and that contact relates to a substantive part of this 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 the AD in light of those comments.

Regulatory findingsPage 2

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-46-AD” in your request.

Adoption of the amendmentPage 2

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:

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

1. The FAA amends § 39.13 by adding the following new airworthiness directive (AD):

Affected TCDS · 1

The type certificate data sheets for the models this AD names, matched by model and maker.

Registered aircraft · 670

Registered aircraft whose airframe or engine model this AD names. Matched by model only, so check each against the AD’s applicability.

By aircraft maker
  • Cessna448 aircraft
  • Textron222 aircraft
By year built
19932026
Registered aircraft by year built: 633 aircraft
199330
199437
199514
199629
199739
199833
199933
200034
200142
200212
200310
20047
20054
200610
200714
20089
20094
20103
20112
201315
201429
201532
201620
201726
201825
201917
202012
202118
202224
202317
202410
202511
202611

37 with no year recorded

By model

Aircraft

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NTSB investigations that cite this AD · 1

Their narratives or probable cause name AD 2003-21-07, often to say whether the aircraft complied with it.