Airworthiness Directives; Cessna Model 441, 500, 550, and 560 Series Airplanes

[Federal Register Volume 60, Number 160 (Friday, August 18, 1995)] [Proposed Rules] [Pages 43089-43091] From the Federal Register Online via the Government Publishing Office [www.gpo.gov] [FR Doc No: 95-20505]

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 95-NM-56-AD]

Airworthiness Directives; Cessna Model 441, 500, 550, and 560 Series Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: This document proposes the adoption of a new airworthiness directive (AD) that is applicable to certain Cessna Model 441, 500, 550, and 560 series airplanes. This proposal would require replacement of outflow/safety valves with serviceable valves. This proposal is prompted by a report of cracking and subsequent failure of outflow safety valves in the pressurization system. The actions specified by the proposed AD are intended to prevent such cracking and subsequent failure of the outflow/safety valves, which could result in rapid decompression of the airplane.

DATES: Comments must be received by October 16, 1995.

ADDRESSES: Submit comments in triplicate to the Federal Aviation Administration (FAA), Transport Airplane Directorate, ANM-103, Attention: Rules Docket No. 95-NM-56-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056. Comments may be inspected at this location between 9:00 a.m. and 3:00 p.m., Monday through Friday, except Federal holidays.

-The service information referenced in the proposed rule may be obtained from Allied Signal, Inc., Controls and Accessories, 1110 North Oracle Road, Tucson, Arizona 85737-9588. This information may be examined at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the FAA, Transport Airplane Directorate, Los Angeles Aircraft Certification Office, 3960 Paramount Boulevard, Lakewood, California.

FOR FURTHER INFORMATION CONTACT: Walter Eierman, Aerospace Engineer, Systems and Equipment Branch, ANM-130L, FAA, Los Angeles Aircraft Certification Office, 3960 Paramount Boulevard, Lakewood, California 90712; telephone (310) 627-5336; fax (310) 627-5210.

SUPPLEMENTARY INFORMATION:

Comments Invited -

Interested persons are invited to participate in the making of the proposed 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 above. All communications received on or before the closing date for comments, specified above, will be considered before taking action on the proposed rule. The proposals contained in this notice may be changed in light of the comments received. - Comments are specifically invited on the overall regulatory, economic, environmental, and energy aspects of the proposed 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 summarizing each FAA-public contact concerned with the substance of this

[[Page 43090]] proposal will be filed in the Rules Docket. - Commenters wishing the FAA to acknowledge receipt of their comments submitted in response to this notice must submit a self-addressed, stamped postcard on which the following statement is made: ``Comments to Docket Number 95-NM-56-AD.'' The postcard will be date stamped and returned to the commenter.

Availability of NPRMs -

Any person may obtain a copy of this NPRM by submitting a request to the FAA, Transport Airplane Directorate, ANM-103, Attention: Rules Docket No. 95-NM-56-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056. Discussion

The FAA has received a report of the failure of a safety valve in the pressurization system on a Learjet Model 31A airplane. Failure of the valve resulted in depressurization of the cabin. Investigation revealed that the poppets of certain outflow/safety valves were cracked. These discrepant valves, including the safety valve installed on the incident airplane, had been manufactured since January 1, 1989. Certain valves manufactured since that date have been found to be susceptible to cracking due to an improper molding process. Cracking in the poppets of the outflow/safety valves in the pressurization system can result in an open valve with an effective flow area of 4.4 square inches; additionally, the valve may close and remain closed. This condition, if not corrected, could result in cracking and subsequent failure of the airflow/safety valves, which could lead to rapid decompression of the airplane. - On March 9, 1995, the FAA issued a proposed rule (Docket 94-NM-211- AD, 60 FR 14231, March 16, 1995), applicable to certain Learjet Model 24, 25, 31, 35, 36, and 55 series airplanes and Learjet Model 28 and 29 airplanes, to address the unsafe condition described previously. The outflow/safety valves installed on these airplanes are similar to the valves installed on Cessna Model 441, 500, 550, and 560 series airplanes. Therefore, the FAA has determined that the latter airplane models also are subject to the unsafe condition described previously. - The FAA has reviewed and approved the following Allied Signal Aerospace Service Bulletins: - 1. Service Bulletin 103576-21-4054, dated January 30, 1995 (for Cessna Model 441 series airplanes); - 2. Service Bulletin 103576-21-4056, dated January 30, 1995 (for Cessna Model 500 and 550 series airplanes); and 3. Service Bulletin 103648-21-4055, dated January 30, 1995 (for Cessna Model 560 series airplanes). These service bulletins describe procedures for replacement of certain discrepant outflow/safety valves with serviceable valves. Since an unsafe condition has been identified that is likely to exist or develop on other products of this same type design, the proposed AD would require replacement of certain discrepant outflow/ safety valves with serviceable valves. The actions would be required to be accomplished in accordance with the service bulletins described previously. As a result of recent communications with the Air Transport Association (ATA) of America, the FAA has learned that, in general, some operators may misunderstand the legal effect of AD's on airplanes that are identified in the applicability provision of the AD, but that have been altered or repaired in the area addressed by the AD. The FAA points out that all airplanes identified in the applicability provision of an AD are legally subject to the AD. If an airplane has been altered or repaired in the affected area in such a way as to affect compliance with the AD, the owner or operator is required to obtain FAA approval for an alternative method of compliance with the AD, in accordance with the paragraph of each AD that provides for such approvals. A note has been included in this notice to clarify this long-standing requirement. There are approximately 150 Cessna Model 441, 500, 550, and 560 series airplanes of the affected design in the worldwide fleet. The FAA estimates that 120 airplanes of U.S. registry would be affected by this proposed AD, that it would take approximately 12 work hours per airplane to accomplish the proposed actions, and that the average labor rate is $60 per work hour. Based on these figures, the total cost impact of the inspection requirement of this proposal on U.S. operators is estimated to be $86,400, or $720 per airplane. However, the manufacturer has advised that it will provide replacement parts at no cost to the operator and will reimburse operators for the labor costs of the required removal and replacement. The regulations proposed herein would not have substantial direct effects 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, in accordance with Executive Order 12612, it is determined that this proposal would not have sufficient federalism implications to warrant the preparation of a Federalism Assessment. For the reasons discussed above, I certify that this proposed regulation (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) if promulgated, 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. A copy of the draft regulatory evaluation prepared for this action is contained in the Rules Docket. A copy of it may be obtained by contacting the Rules Docket at the location provided under the caption ADDRESSES.

List of Subjects in 14 CFR Part 39

Air transportation, Aircraft, Aviation safety, Safety.

The Proposed Amendment

Accordingly, pursuant to the authority delegated to me by the Administrator, the Federal Aviation Administration proposes to amend 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), 40101, 40113, 44701.

Sec. 39.13 [Amended]

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

Cessna Aircraft Company: Docket 95-NM-56-AD.

Applicability: Model 441, 500, 550, and 560 series airplanes; equipped with Allied Signal outflow/safety valves; as identified in Allied Signal Aerospace Service Bulletins 103576-21-4054, 103576-21- 4056, and 103648-21-4055, all dated January 30, 1995; certificated in any category.

Note 1: This AD applies to each airplane identified in the preceding applicability provision, regardless of whether it has been modified, altered, or repaired in the area subject to the requirements of this AD. For airplanes that have been modified, altered, or repaired so that the performance of the requirements of this AD is affected, the owner/operator must use the authority provided in paragraph (c) of this AD to request approval from the FAA. This approval may address either no action, if the current configuration eliminates the unsafe condition; or different actions necessary to address the unsafe condition described in

[[Page 43091]] this AD. Such a request should include an assessment of the effect of the changed configuration on the unsafe condition addressed by this AD. In no case does the presence of any modification, alteration, or repair remove any airplane from the applicability of this AD.

Compliance: Required as indicated, unless accomplished previously.

To prevent cracking and subsequent failure of the outflow/safety valves, which would result in rapid decompression of the airplane, accomplish the following:

(a) Within 18 months after the effective date of this AD, replace the outflow/safety valve in accordance with Allied Signal Aerospace Service Bulletin 103576-21-4054 (for Model 441 series airplanes), 103576-21-4056 (for Model 500 and 550 series airplanes), or 103648-21-4055 (for Model 560 series airplanes), all dated January 30, 1995, as applicable.

(b) As of the effective date of this AD, no person shall install an outflow/safety valve, having a part number and serial number identified in Allied Signal Aerospace Service Bulletin 103576-21- 4054 (for Model 441 series airplanes), 103576-21-4056 (for Model 500 and 550 series airplanes), or 103648-21-4055 (for Model 560 series airplanes), all dated January 30, 1995, on any airplane unless that valve is considered to be serviceable in accordance with the applicable service bulletin.

(c) An alternative method of compliance or adjustment of the compliance time that provides an acceptable level of safety may be used if approved by the Manager, Los Angeles Aircraft Certification Office (ACO), FAA, Transport Airplane Directorate. Operators shall submit their requests through an appropriate FAA Principal Maintenance Inspector, who may add comments and then send it to the Manager, Los Angeles ACO.

Note 2: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Los Angeles ACO.

(d) Special flight permits may be issued in accordance with sections 21.197 and 21.199 of the Federal Aviation Regulations (14 CFR 21.197 and 21.199) to operate the airplane to a location where the requirements of this AD can be accomplished.

Issued in Renton, Washington, on August 14, 1995.

S.R. Miller,

Acting Manager, Transport Airplane Directorate, Aircraft Certification Service.

[FR Doc. 95-20505 Filed 8-17-95; 8:45 am]

BILLING CODE 4910-13-U