Airworthiness Directives; Cessna Model 500, 501, 550, and 551 Airplanes

AGENCY:

Federal Aviation Administration, DOT.

ACTION:

Supplemental notice of proposed rulemaking; reopening of comment period.

SUMMARY:

This document revises an earlier proposed airworthiness directive (AD); applicable to certain Cessna Model 500, 501, 550, and 551 airplanes; that would have required inspection of the piston housing for an “SB” impression stamp; a one-time inspection of the brake assembly to detect cracked or broken brake stator disks; and replacement of the brake assembly with a new or serviceable assembly, if necessary. This new action revises the proposed rule by eliminating the inspection of the brake assembly to determine if the letters “SB” have been impression-stamped on the piston housing, and, instead, requiring a one-time inspection of the brake stator disks to determine to what change level they have been modified (if any), and follow-on actions if necessary. This new proposed AD would also require that the existing markings on the piston housing of certain brake assemblies be eliminated. The actions specified by this new proposed AD are intended to prevent wheel lockups that may be caused by cracked or broken brake stator disks becoming jammed in the brake assembly and preventing rotation. Such jamming of the brake assembly may result in reduced directional control or braking performance during landing. This action is intended to address the identified unsafe condition.

DATES:

Comments must be received by December 8, 2003.

ADDRESSES:

Submit comments in triplicate to the Federal Aviation Administration (FAA), Transport Airplane Directorate, ANM-114, Attention: Rules Docket No. 2000-NM-65-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 (425) 227-1232. Comments may also be sent via the Internet using the following address: 9-anm-nprmcomment@faa.gov. Comments sent via fax or the Internet must contain “Docket No. 2000-NM-65-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 the proposed rule 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; or at the FAA, Wichita Aircraft Certification Office, 1801 Airport Road, Room 100, Mid-Continent Airport, Wichita, Kansas 67209.

FOR FURTHER INFORMATION CONTACT:

David Hirt, Aerospace Engineer, Systems and Propulsion Branch, ACE-116W, Wichita Aircraft Certification Office, 1801 Airport Road, Room 100, Mid-Continent Airport, Wichita, Kansas 67209; telephone (316) 946-4156; fax (316) 946-4407.

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 action may be changed in light of the comments received.

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 proposed 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 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 proposal will be filed in the Rules Docket.

Commenters wishing the FAA to acknowledge receipt of their comments submitted in response to this action must submit a self-addressed, stamped postcard on which the following statement is made: “Comments to Docket Number 2000-NM-65-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-114, Attention: Rules Docket No. 2000-NM-65-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056.

Discussion

A proposal to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) to add an airworthiness directive (AD); applicable to certain Cessna Model 500, 501, 550, and 551 airplanes; was published as a notice of proposed rulemaking (NPRM) in the Federal Register on September 7, 2000 (65 FR 54182). That NPRM would have required inspection of the piston housing for an “SB” impression stamp; a one-time inspection of the brake assembly to detect cracked or broken brake stator disks; and replacement of the brake assembly with a new or serviceable assembly, if necessary. That NPRM was prompted by several reports of wheel lockups that appear to be caused by cracked or broken brake stator disks becoming jammed in the brake assembly and preventing rotation. Such jamming of the brake assembly may result in reduced directional control or braking performance during landing.

Actions Since Issuance of Previous Proposal

Since the issuance of that NPRM, BFGoodrich has issued Goodrich Service Bulletins 2-1528-32-2 (for airplanes equipped with BFGoodrich brake assembly part number (P/N) 2-1528-6) and 2-1530-32-2 (for airplanes equipped with BFGoodrich brake assembly P/N 2-1530-4), both Revision 5, both dated February 19, 2003. (The original NPRM refers to BFGoodrich Service Bulletins 2-1528-32-2 and 2-1530-32-2, both Revision 1, both dated February 3, 2000, as the appropriate source of service information for the actions proposed by that NPRM.) Revision 5 of the service bulletins eliminates the inspection of the brake assembly to determine if the letters “SB” have been impression-stamped on the piston housing. That action was described in earlier revisions of the service bulletins, and in paragraph (a) of the original NPRM, as a method of determining whether it was necessary to inspect the brake stator disks for cracking. Since the issuance of the original NPRM, it has been determined that “SB” may be stamped on the piston housing of certain brake assemblies having stator disks that must be inspected for cracking. Thus, it is necessary to inspect all stator disks installed on BFGoodrich brake assemblies having P/N 2-1528-6 or 2-1530-4 to determine whether they are impression-stamped with “CHG AI” or with a change letter “B” or higher, and to inspect for cracking of subject stator disks and replace them if necessary.

Also since the issuance of the original NPRM, BFGoodrich has issued service bulletins 2-1528-32-3 (for BFGoodrich brake assembly P/N 2-1528-6) and 2-1530-32-3 (for BFGoodrich brake assembly P/N 2-1530-4), both dated March 23, 2000. Those service bulletins apply to BFGoodrich brake assemblies having P/N 2-1528-6 or 2-1530-4 that are used as spare parts. The service bulletins describe procedures for an inspection of the stator disks installed on those brake assemblies to determine whether they are impression-stamped with “CHG AI” or with a change letter “B” or higher, and replacement of subject stator disks with new disks.

Accomplishment of the actions specified in the applicable service bulletin is intended to adequately address the identified unsafe condition.

Differences Between Service Bulletins and Supplemental NPRM

This supplemental NPRM differs from the service bulletins in that for any stator disk not stamped with “CHG AI” or “CHG B” or a higher change letter, if the piston housing is impression-stamped with the letters “SB,” this supplemental NPRM would require that the existing markings on the piston housing be removed by stamping “XX” over the letters “SB.” Though the service bulletin does not specify this action, we find that it is necessary to require this action to ensure that it is evident that the actions proposed by this supplemental NPRM have been accomplished on the affected parts.

This supplemental NPRM also differs from the service bulletins in that it would require accomplishing an initial inspection to determine the change letter of the brake stator disks within 50 landings or 90 days after the effective date of this AD, whichever occurs first. We find that this compliance time is consistent with that proposed in the original NPRM and is adequate to ensure the continued flight safety of the affected airplane fleet. For any stator disk not stamped with “CHG AI” or “CHG B” or a higher change letter, the compliance time for the detailed inspection for cracked or broken stator disks is consistent with the compliance time given in the service bulletin for those actions.

Comments

Due consideration has been given to the comments received from a single commenter in response to the original NPRM.

Request To Clarify Proposed Requirement

The commenter requests that the FAA revise paragraph (b) of the original NPRM to specify that the requirements of that paragraph need only be accomplished if “SB” is not impression-stamped on the piston housing. The commenter states that this would provide necessary clarification.

We do not concur. As explained previously, we have determined that even if “SB” is impression-stamped on the piston housing, all subject brake assemblies must be inspected to ensure that all stator disks are impression-stamped with “CHG AI” or with a change letter “B” or higher. We have made no change to the supplemental NPRM in this regard, other than the changes associated with the new service information described previously.

Request To Withdraw NPRM

The commenter, the brake manufacturer, believes that the current inspection criteria and fleet compliance has reasonably addressed the issue of broken brake stator disks and that the proposed AD is not required. The commenter makes the following statements to justify its request:

• A reduction in the repetitive interval for replacing brakes on airplanes operated in the most severe conditions appears to have greatly reduced the occurrence of stator failures.
• Since the issuance of the BFGoodrich service bulletins referenced in the original NPRM, the commenter is not aware of any additional reports of locked wheels caused by broken brake stator disks.
• Brakes and brake stator disks in spares inventories have been addressed through the issuance of BFGoodrich Service Bulletins 2-1528-32-3 and 2-1530-32-3.
• Operators of subject airplanes have been briefed about the problem of cracked or broken brake stator disks.
• Cessna reports that 70 percent of the worldwide fleet of affected airplanes have already complied with the actions that would be required by the proposed AD.

We acknowledge the facts presented by the commenter. However, we do not agree that it is appropriate to withdraw the proposed AD. It is necessary to issue an AD to ensure that all affected airplanes are inspected and that the necessary corrective actions are accomplished to eliminate the unsafe condition. In addition, issuance of an AD also assists us in meeting our obligation to advise other civil airworthiness authorities of unsafe conditions identified in products manufactured in the United States, in accordance with various bilateral airworthiness agreements with countries around the world. Therefore, it is both warranted and necessary to issue this AD.

Request for Information on Additional Incidents

The commenter notes that it is aware of 3 reports of a locked wheel and 16 reports of broken stator disks. The commenter asks the FAA to provide it with information on additional reports of incidents of locked wheels resulting from broken brake stator disks.

We have not received any reports of locked wheels resulting from broken brake stator disks other than those noted by the commenter. We have made no change to the supplemental NPRM in this regard.

Request To Revise Cost Impact

The commenter requests that the cost information in the original NPRM be revised to reflect exactly the cost information provided in the relevant BFGoodrich service bulletins. We do not concur. It is our practice to round up work hour figures to a whole number, which is how we arrived at the work hour estimates provided in the original NPRM. We have made no change to the supplemental NPRM in this regard.

Explanation of Additional Change to Original NPRM

For clarification and to reflect model designations in the most recent revision of the Type Certificate Data Sheet for the affected airplanes, we have revised all references to “Cessna Model 500 series airplanes” in the original NPRM to refer to “Cessna Model 500, 501, 550, and 551 airplanes” in this supplemental NPRM.

Conclusion

Since the changes related to the newly issued service information expand the scope of the originally proposed rule, we have determined that it is necessary to reopen the comment period to provide additional opportunity for public comment.

Changes to 14 CFR Part 39/Effect on the Proposed AD

On July 10, 2002, we issued a new version of 14 CFR part 39 (67 FR 47997, July 22, 2002), which governs our AD system. This regulation now includes material that relates to altered products, special flight permits, and alternative methods of compliance (AMOCs). Because we have now included this material in part 39, only the office authorized to approve AMOCs is identified in each individual AD. Therefore, in this supplemental NPRM, we have removed Note 1 and paragraph (d) and revised paragraph (c) of the original NPRM.

Change to Labor Rate Estimate

Since the issuance of the original NPRM, we have reviewed the figures we have used over the past several years to calculate AD costs to operators. To account for various inflationary costs in the airline industry, we find it necessary to increase the labor rate used in these calculations from $60 per work hour to $65 per work hour. The cost impact information, below, reflects this increase in the specified hourly labor rate.

Cost Impact

There are approximately 370 airplanes of the affected design in the worldwide fleet. We estimate that 259 airplanes of U.S. registry would be affected by this proposed AD. It would take up to 1 work hour per airplane to accomplish the proposed inspection if the inspection were done at the time of a tire change and up to 4 work hours per airplane if the inspection were done at a different time, at an average labor rate of $65 per work hour. Based on these figures, the cost impact of the proposed AD on U.S. operators is estimated to be $16,835, or $65 per airplane, for inspections of the brake assembly done at the time of a tire change; or up to $67,340, or $260 per airplane, for inspections done at a different time.

The cost impact figures discussed above are based on assumptions that no operator has yet accomplished any of the proposed requirements of this AD action, and that no operator would accomplish those actions in the future if this AD were not adopted. The cost impact figures discussed in AD rulemaking actions represent only the time necessary to perform the specific actions actually required by the AD. These figures typically do not include incidental costs, such as the time required to gain access and close up, planning time, or time necessitated by other administrative actions.

Regulatory Impact

The regulations proposed herein 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. Therefore, it is determined that this proposal would not have federalism implications under Executive Order 13132.

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), 40113, 44701.