Skip Ribbon Commands
Skip to main content
Safety Recommendation Details

Safety Recommendation H-02-021
Details
Synopsis: On May 31, 2001, about 3:28 p.m. central daylight time, a southbound Gayle Stuart Trucking, Inc., truck-tractor semitrailer exited Interstate 540 at State Highway 282 (SH-282) near Mountainburg. The driver was unable to stop at the stop sign at the bottom of the ramp. The 79,040-pound combination unit was traveling approximately 48 mph when it entered the intersection and collided with the right side of a westbound, 65-passenger, 1990 Blue Bird Corporation school bus operated by the Mountainburg, Arkansas, Public Schools. The school bus rotated approximately 300 degrees clockwise and overturned; the body, which partially separated from the chassis, came to rest on its right side on the eastbound shoulder of SH-282. The tractor semitrailer continued across the roadway, rotated about 60 degrees clockwise, overturned, and came to rest on its left side. Three school bus passengers seated across from the impact area were fatally injured; one was partially ejected. Two other passengers, one of whom was seated in the impact area, received serious injuries, and four passengers had minor injuries. The school bus driver and the truckdriver both sustained minor injuries.
Recommendation: The National Transportation Safety Board recommends that the National Fire Protection Association: Amend National Fire Protection Association Standard 58, Storage and Handling of Liquefied Petroleum Gas, to require that (1) propane fuel systems installed in school buses be protected and (2) propane fuel systems meet the equivalent to Federal Motor Vehicle Safety Standard 301 crash protection standards.
Original recommendation transmittal letter: PDF
Overall Status: Closed - Acceptable Alternate Action
Mode: Highway
Location: Mountainburg, AR, United States
Is Reiterated: No
Is Hazmat: No
Is NPRM: No
Accident #: HWY01MH025
Accident Reports: Collision Between Truck-Tractor Semitrailer and School Bus
Report #: HAR-02-03
Accident Date: 5/31/2001
Issue Date: 9/13/2002
Date Closed: 6/2/2004
Addressee(s) and Addressee Status: National Fire Protection Association (Closed - Acceptable Alternate Action)
Keyword(s):

Safety Recommendation History
From: NTSB
To: National Fire Protection Association
Date: 6/2/2004
Response: NFPA reported that the issue had been reviewed in depth at the 2003 meeting of the Technical Committee on Liquefied Petroleum Gases. This NFPA committee also received comments from the Technology and Standards Committee of the National Propane Gas Association (NPGA) concerning crashworthiness of propane tanks used on permanently installed vehicle fuel systems. The Safety Board notes that the NPGA reported on several crash and drop tests performed on propane fuel tanks, which showed the tanks to be less susceptible to rupture and spillage than typical vehicle liquid fuel tanks. NFPA also reported that changes incorporated in the 2004 edition of NFPA 58, Liquefied Petroleum Gas Code, will require that permanently installed vehicle propane fuel containers, including those on school buses, be equipped with valving at the liquid outlet connection such that there can be no fuel flow from the container when the engine is not in an operating mode, irrespective of the position of the vehicle's ignition key. This requirement will be in addition to the existing requirement for an excess flow valve in the liquid outlet connection. The Safety Board's recommendation addresses protections for propane tanks installed on school buses that may be susceptible to damage or puncture during highway collisions. Although important safety features, outlet valving controlled by the engine operating mode and excess flow valves do not protect tanks from accident-induced damage. However, the Board is persuaded by NFPA's documentation of vehicle propane fuel container testing, including drop tests and crash tests, and agrees that the propane containers used on school buses for engine fuel applications have significant crashworthiness due to their design characteristics. Accordingly, Safety Recommendation H-02-21 is classified "Closed--Acceptable Alternate Action."

From: National Fire Protection Association
To: NTSB
Date: 12/31/2003
Response: Letter Mail Controlled 1/6/2004 2:12:33 PM MC# 2040001 This recommendation was forwarded in 2002 for processing to the NFPA Technical Committee on Liquefied Petroleum Gases that is administratively responsible for changes to NFPA 58, Liquefied Petroleum Gas Code. As background the initial NTSB recommendation was received just after the committee met in September 2002 to act on proposals for the 2004 edition of NFPA 58, but the item was still entered as a committee proposal after the meeting to facilitate processing at the next stage of the revision process (reference: Proposal 58-106. F2003 ROP. pg. 50). This allowed the topic to be published for public comment. and it further allowed it to be fully addressed at the committee's next meeting in 2003. The committee also requested a recommendation from the Technology and Standards Committee of the National Propane Gas Association (NPGA) with a request that this NPGA Committee respond in the form of a public comment that could be acted on at the 2003 meeting of the Technical Committee on Liquefied Petroleum Gases. The committee had their follow-up ROC meeting in late spring of 2003 and further addressed this matter at that time. Upon review it was noted that an applicable change was already in process based on an earlier proposal to require that permanently installed vehicle propane fuel containers be equipped with valving such that there can be no fuel flow from the container when the engine is not in an operating mode, irrespective of the position of the vehicle's ignition key. The committee subsequently confirmed this change at the KOC stage, which modifies section 8.2.3 of the 2004 edition of NFPA 58 (reference: Proposal 58-103, F2003 ROP, page 50). In addition to the changes being made to section 8.2.3, an additional review of this subject was facilitated by the public comment submitted by the NPGA Technology and Standards Committee (reference: Comment 58-258. F2003 ROC, pg. 467). This comment provided a detailed substantiation as to why further action in addition to the afore-mentioned Proposal 58-103 on section 8.2.3 was not necessary at this time. The Technical Committee on Liquefied Petroleum Gases accepted Comment 58-258, and consequently no further directly related changes were processed in the 2003 edition of NFPA 58. For convenience the following is an excerpt of the rationale submitted by the NPGA committee in Comment 58-258 and accepted by the NFPA Technical Committee on Liquefied Petroleum Gases: In response to the request of the NFPA Technical Committee on LP-Gas regarding the action taken on Proposal 58-106, the National Propane Gas Association offers the following for the consideration of the committee. The current requirements of NFPA 58, and revisions already in progress for the 2004 edition of NFPA 58, do provide protection for propane fuel containers used on vehicles, including school buses. The committee made a revision to 8.2.3 (g) (Proposal 58-103) to enhance the integrity of all propane engine fuel systems. This change will require a valve in the liquid outlet connection of a propane engine fuel container, which is actuated both manually and automatically when the engine is not in operating mode, independent of the ignition switch position. This new requirement is in addition to the requirement for an excess flow valve in the liquid outlet of the vehicular propane container. In implementing this additional requirement the committee recognized that excess flow valves could not be relied upon to stop flow in all accident conditions. It must be noted that a propane engine fuel container is an ASME pressure vessel that provides a significantly greater level of protection than the tanks used for liquid fuels on vehicles (including school buses). ASME containers in propane service are required to have a design pressure of 250 psi. ASME containers in propane service as vehicular fuel containers are required to have a design pressure of 312 psi, a 25% increase in working pressure with a corresponding increase in shell thickness. The ASME code requires a design margin of 3.5, providing additional container thickness. In addition, the cylindrical shape of an ASME propane engine fuel container provides additional ability to withstand damage. Liquid fuel containers are thin wall vessels designed to contain the liquid only. Where installed on vehicles, they require protection not needed for propane containers. In contrast, as noted above, propane containers used on school buses for engine fuel applications have significant crash-worthiness due to their design characteristics. There have been crash tests of propane fueled vehicles that have confirmed an adequate level of protection exists in the case of an accident. A series of propane fueled bus tests was conducted by the Netherlands Organization for Applied Technical Research (TNO). A report issued in 1983 described four city bus crash tests that resulted in only one instance of a minor leak. It is noted that the leak was in the liquid outlet valve, which is addressed in the revision made to the 2004 edition of NFPA 58. In addition, TNO conducted tests involving propane fueled automobiles, showing only minor leakage following head-on and rear end crashes at 50 - 60 km/hr (31-37 mph). While these tests were conducted under conditions not as serious as the school bus incident investigated by NTSB, they do show a high level of safety in vehicle propane fuel container installations. Drop tests have been conducted by the propane industry on engine fuel tanks. In one series of tests, plastic gasoline tanks, steel gasoline tanks, and steel propane tanks were filled to their maximum permitted filling level and were dropped vertically from a height of 30 feet onto a steel plate mounted on a concrete slab, with the tanks striking the plate at varying angles. Both the plastic and steel gasoline tanks released their entire liquid contents upon impact and the steel propane tanks retained their contents with no leakage. The National Propane Gas Association will review any new information that becomes available on the subject.

From: NTSB
To: National Fire Protection Association
Date: 11/11/2003
Response: "sent via email: In February of this year the NFPA indicated that the Technical Committee on Liquefied Petroleum Gases would consider the recommendation in May 2003 and a Report on Comments (ROC would be available in September 2003. Has the ROC been published? If so, what were the comments on the issue concerning propane fuel systems in school buses as addressed in the recommendation?"

From: NTSB
To: National Fire Protection Association
Date: 6/10/2003
Response: The Safety Board notes that the NFPA Technical Committee on Liquefied Gases, which is responsible for NFPA Standard 58, is publishing Safety Recommendation H-02-21 in its Report on Proposals to allow the public to comment and to consider changes for the 2004 edition of the standard. In addition, the NFPA Technical Committee Chair has requested input from the National Propane Gas Association and has invited their Technology and Standards Committee to submit comments on this safety recommendation. The Safety Board looks forward to hearing the outcome of the meeting held in May 2003, where public comments and options for change will be discussed. Pending the receipt of future correspondence from the NFPA indicating that Standard 58 has been updated to comply with this recommendation, Safety Recommendation H-02-21 is classified "Open--Acceptable Response."

From: National Fire Protection Association
To: NTSB
Date: 2/24/2003
Response: Letter Mail Controlled 3/5/2003 4:37:42 PM MC# 2030123 The document addressing propane-fueled vehicles is NFPA 58, Liquefied Petroleum Gas Code. The NFPA Technical Committee on Liquefied Petroleum Gases, responsible for NFPA 58, met the week before the NTSB Recommendation was received in our offices, and therefore it was not part of the Committee's agenda. The Committee agreed that the subject should be considered in a timely fashion, and created a Committee proposal incorporating NTSB's Recommendation. Because the NTSB Recommendation did not contain specific language to revise NFPA 58, and because the Committee was unable to review the matter in detail, it was "rejected" with the following statement: "The Committee, however, intends to review this issue further, and is directing that the Recommendation be published in the Report on Proposals so that the public can comment and it can be considered at the next meeting." The Committee's action will get the NTSB Recommendation into the NFPA codes and standards process in a timely manner. The proposal the Committee crafted was included in the Fall 2003 Report on Proposals (1~01'). This report is now available from NFPA or through the NFPA homepage, www.nfna.org. Refer to proposal number 58-106 (attached). The action taken by the NFPA Committee allows them to consider these changes for the 2004 edition of NFPA 58 during their next deliberations. The Committee will act on all comments on proposals (including proposal 5%105), contained in the ROP and received on or before the comment closing date, March 26, 2003. In addition, the NFPA Technical Committee Chair requested input from the National Propane Gas Association, and specifically invited their Technology and Standards Committee to submit a comment on the NTSB Recommendation. All NFPA Technical Committee meetings are open to the public. We invite members of your staff with knowledge of the accident to attend the meeting in May to share details with the Technical Committee on Liquefied Petroleum Gases. The Committee's actions on public comments considered at its upcoming May, 2003 meeting will be published in the Fall 2003 Report on Comments (ROC) available in September 2003. We will advise you of the action taken when the ROC is published.