Blue Bird Body Company (Blue Bird), 402 N. Camellia Blvd., P.O. Box 937, Fort Valley, Georgia 31030, has determined that 25,839 model TC/2000 Conventional and MiniBird school buses do not meet the 60 percent tensile strength requirements of 49 CFR 571.221, Federal Motor Vehicle Safety Standard (FMVSS) No. 221, “School bus body joint strength,” and has filed an appropriate report pursuant to 49 CFR Part 573, “Defect and Noncompliance Reports.” Blue Bird has also applied to be exempted from the notification and remedy requirements of 49 U.S.C. Chapter 301—“Motor Vehicle Safety” on the basis that the noncompliance is inconsequential to motor vehicle safety.
Notice of receipt of the application was published, with a 30-day comment period, on March 13, 2000 in the Federal Register (65 FR 13412). The National Highway Traffic Safety Administration (NHTSA) received no comments.
FMVSS No. 221, S5, requires that, when tested in accordance with the test procedures of S6, each body panel joint shall be capable of holding the body panel to the member to which it is joined when subjected to a force of 60 percent of the tensile strength of the weakest joined body panel, determined pursuant to S6.2.
Blue Bird has notified NHTSA that the subject school buses were manufactured at its Mount Pleasant, Iowa, plant from November 1, 1993 through December 6, 1999. The noncompliance involves a failure to meet the 60 percent joint strength requirements on certain 8-inch segments of the exterior roof joints. Agency compliance tests, performed by General Testing Laboratories (GTL), determined that the tensile strength of the roof joint tested was 54.9 percent of the required load. Blue Bird stated that a variance in rivet spacing in the vicinity of the roof stringers occurred as some assembly workers at this plant, without authorization, departed from manufacturing procedures of using the pre-punched holes in the roof bows as drill guides to control fastener spacing and, as a result, there are fewer than the six rivets required by Blue Bird in certain 8-inch segments of the roof joints in the affected buses.
Blue Bird supported its application for inconsequential noncompliance with the following statements which have been quoted from its petition:
I. Overall Joint and Body Strength
Blue Bird stated that the purpose of the School Bus Body Joint Strength Standard No. 221 is to reduce deaths and injuries resulting from the structural collapse of school bus bodies during crashes. Blue Bird concluded from the previous rulemakings discussion that the strength of the overall joint and consequently the strength of the overall bus body is the safety objective of Standard 221 and that the measured performance of an eight (8) -inch long joint segment is merely a procedure chosen to evaluate the overall joint in a practical manner.
Blue Bird stated that by that its analysis shows that the overall strengths of the roof joints on the subject test bus not only meet, but comfortably exceed the strength performance requirements of FMVSS 221. Consequently, Blue Bird believes that the noncompliance of several small selected segments of these roof joints is not representative of actual, overall bus body strength performance and is inconsequential as it relates to motor vehicle safety. Start Printed Page 48823
II. Occupants Not Exposed to Roof Joints
Blue Bird stated that, in a crash, vehicle occupants are not exposed to exterior joints like the roof joint in question. Also of importance is the fact that the few small segments of exterior roof joints believed to be in noncompliance are completely separated from the occupant compartment by headlining panels with joints in full compliance with FMVSS 221 requirements.
III. Interior Headlining Joint and Overall Bus Body Joint Strength
Blue Bird reiterated that the overall strength of the joints is of critical importance with regard to the purpose of Standard 221. Blue Bird argued that the test results showed that the headlining joint performance was 71.3 percent vs. the 60 percent requirement. Blue Bird further argued that if the strength of the entire body joint consisting of both the interior headlining joint and the exterior roof joint were to be analyzed together, the overall performance of the joint would be 62.4 percent, which exceeds the 60 percent requirement of FMVSS 221 and satisfies the stated purpose and safety objectives of the standard.
IV. The Remedy in This Case Could Result in Degradation and Leakage of Bus Body Panels
Blue Bird argued that there is no safety need to require notification and remedy of the subject school buses to add additional fasteners. Blue Bird stated that in reality, a recall of the subject buses would be counterproductive to safety in that the resulting inconvenience to the owners/operators of the buses could disrupt the service they provide, resulting in the use of much less safe means of transportation.
Blue Bird stated that the only feasible remedy on completed buses is the addition of blind repair (pop type) rivets in the areas where there are fewer than six (6) rivets in each eight (8)-inch segment. Blue Bird argued that blind rivets are susceptible to water leaks and the installation of these rivets could result in mechanical damage to the roof joint sealer and possible damage to the exterior body paint. Water leaks and/or possible corrosion could occur as a result of the mechanical damage done during drilling and rivet installation.
V. The Current Status of FMVSS 221 Indicates that Curved Joints Are Not A Safety Concern
Blue Bird argued that the current version of FMVSS 221, which permitted optional early compliance as of November 5, 1998, provides an instructive insight into the agency's position with respect to curved joint testing. The November 1998 final rule (see Reference 3), in § S5.2.2, appears to exclude all curved and complex joints from the 60 percent strength requirements of § S5.1.2. Blue Bird argued that intent of the agency was to exclude all curved joints from the joint tensile strength requirements of revised Standard 221. Blue Bird argue that until the standard properly defines what does or does not constitute a “curved joint,” the actual requirements that roof and ceiling joints must meet will continue to be unclear.
VI. There Have Been No Roof Joint Failures in the Field
Blue Bird argued that they have never had a field complaint regarding the strength of roof joints and is not aware of any accidents or crash tests which resulted in roof joint separations within the scope of the Standard. The test bus from which the subject roof joint was obtained had other joints tested and all were found to be in full compliance with all FMVSS 221 requirements.
Blue Bird concluded that the noncompliance is not a safety problem and that the noncompliance is inconsequential and in no way compromises the safety of the subject school buses and that the disruption of our customers and likely degradation of these buses by the indicated remedy is not in the public interest.Start Printed Page 48824
We have reviewed Blue Bird's arguments and do not agree. The primary safety purpose of joint strength requirements in FMVSS No. 221 is to ensure that school bus bodies do not structurally collapse during crashes, thereby causing deaths and injuries. Another purpose is to ensure that school bus body panels do not separate during crashes leaving exposed edges that can result in severe lacerations to passengers. NHTSA does not agree with Blue Bird's assessment that overall joint strength is the intended purpose of FMVSS No. 221. Failure to include adequate joint strength in localized areas of joints can lead to body panel separation in those areas and thus pose a hazard of joints becoming unattached in collisions. Separated joints can lead to occupants becoming seriously or fatally injured from lacerations caused by the separated bus body panels.
In the final rule promulgating FMVSS No. 221, January 27, 1997, NHTSA stated that this standard established the minimum requirements for school bus body crashworthiness and that, “Its purpose is to prevent panels from separating at the joint in the event of an accident. In order to deal with the problem of laceration, this regulation must be applicable to both exterior and interior joints.” The 60 percent joint strength requirement applied equally to both the interior and exterior body panels to ensure that school bus bodies maintained it's integrity in severe crashes. Prior to the implementation of this standard the National Transportation Safety Board (NTSB) investigated several school bus crashes in which the sparsely riveted panels separated in severe crashes contributing to deaths, injuries and ejections when the bus body disintegrated. In a 1987 follow up study “Crashworthiness of Large Poststandard School Buses” NTSB stated that, “School bus bodies withstood crash forces very well, maintaining structural integrity even in severe crash forces.” The agency maintains its earlier conclusion that both interior and exterior joints in bus body panels must meet the 60 percent strength requirement to maintain effective crashworthiness of the school body to mitigate against injuries caused by body panel separation.
The agency also does not agree with Blue Bird that school bus occupants are not exposed to exterior roof joints during crashes. While the agency is not aware of any fatalities or injuries caused by joint separations in the roofs of school buses, the potential exists that inadequate external localized joint strength can lead to possible joint failure of internal joints. Separated exterior joints can cause interior joints to be subjected to higher crash forces and can cause the interior joints to become separated in a crash. Separated joints can lead to the occupants being exposed to the jagged edges and increase the threat of becoming seriously or fatally injured. In the final rule promulgating FMVSS No. 221, January 27, 1997, NHTSA stated that, “In order to deal with the problem of laceration, this regulation must be applicable to both exterior and interior joints.”
The agency also does not agree with Blue Bird that its proposed remedy (blind repair, pop-type rivets) would necessarily result in degradation and leakage of bus body panels. We believe that with the proper use of modern sealants any leakage caused by adding additional discreet fasteners can adequately be prevented. More importantly, if Blue Bird believes that the above remedy is unsafe or inadequate, it is up to Blue Bird to develop and implement an alternative remedy for the noncompliance.
NHTSA also does not agree with Blue Bird's conclusion that the November 5, 1998 final rule amending FMVSS No. 221 excluded all curved joints. The final rule excluded small curved and complex joints from the tensile test requirement that cannot be accommodated in the test apparatus. The joint the agency tested fit in the test apparatus without compromising the integrity of the joint. Blue Bird's internal review, field inspection and analysis showed that the failure to meet the joint strength requirement specified in FMVSS No. 221 was caused by departure from manufacturing procedures. Issues regarding petitions for reconsideration of the November 5, 1998 final rule are irrelevant to petitions for inconsequential noncompliance. These issues will be discussed when the agency responds to the petitions for reconsideration.
In consideration of the foregoing, NHTSA has decided that the applicant has not met its burden of persuasion that the noncompliance described above is inconsequential to motor vehicle safety. Accordingly, its application is denied, and the applicant must now provide the notification of the noncompliance that is required by 49 U.S.C. 30119, and the remedy of the noncompliance, as required by 49 U.S.C. 30120.Start Signature
Issued on: August 4, 2000.
Stephen R. Kratzke,
Associate Administrator for Safety Performance Standards.
[FR Doc. 00-20164 Filed 8-8-00; 8:45 am]
BILLING CODE 4910-59-P