Interpretation ID: 1984-3.29

TYPE: INTERPRETATION-NHTSA

DATE: 09/24/84

FROM: AUTHOR UNAVAILABLE; Frank Berndt; NHTSA

TO: Thomas D. Turner -- Manager, Engineering Services, Blue Bird Body Company

TITLE: FMVSS INTERPRETATION

TEXT: This responds to your letter of August 15, 1984, concerning the application of Standard No. 301, Fuel System Integrity, to school buses with a gross vehicle weight rating of more than 10,000 pounds. You specifically asked about the effect on certification of adding auxiliary equipment to the fuel system. As explained below, you are correct in your understanding that the vehicle with any auxiliary equipment installed on it must be certified as complying with the standard.

You explained that you are receiving more requests for school buses equipped with auxiliary fuel-fired heaters and air conditioners. Those auxiliary devices would be connected to the fuel tank or line of the vehicle. You further explained that the typical auxiliary heating and air-conditioning include fuel powered units mounted to the outside of the chassis frame and/or the underside of the body and located between the outside of the chassis frame and the outside body sheetmetal, where it could be impacted by a moving barrier during the crash test required by Standard No. 301.

Standard No. 301 sets requirements for the integrity of the entire fuel system used in motor vehicles. If auxiliary fuel-powered equipment is installed in a vehicle before its sale to its first purchaser for purposes other than resale, the vehicle with the auxiliary equipment installed must be certified as complying with Standard No. 301.

You explained that because of the variety of different auxiliary fuel systems and the different sizes, types, and configurations of vehicle involved, you believe it is impracticable and economically prohibitive to conduct full scale crash tests. Therefore, you asked about alternative methods of determining compliance. As with all of the agency's standards, Standard No. 301 sets forth the test procedures that the agency will use to determine if a vehicle complies with the performance requirements of a standard. A manufacturer is not required to do crash testing to verify compliance; instead it may rely on such things as engineering analysis or computer simulations to establish that its vehicle conforms with the standard.

Section 108(b)(2) of the National Traffic and Motor Vehicle Safety Act requires a manufacturer to show that it has exercised due care in making its certification that the vehicle conforms with all applicable standards. Whether a manufacturer has exercised due care can only be made on a case-by-case basis. What constitutes "due care" in a particular case depends on all relevant facts, including such things as the limitations on current technology, the availability of test equipment, the size of the manufacturer and above all the diligence evidenced by the manufacturer. The agency would look to such things as the drawing, engineering instructions, and quality assurance procedures that you mentioned in order to make a determination of due care. Although an inspection by an independent laboratory is not required, the existence of such testing would be considered in determining whether a manufacturer has exercised due care.

Finally you asked if any manufacturers are currently relying on methods other than crash testing to determine whether their vehicles conform with our standard. Since manufacturers are required to self-certify their vehicles and are not required to receive any approval from this agency before making their certifications, I cannot answer your question. I note that in instances where there has been a question of whether a vehicle complies with Standard No. 301, manufacturers have provided crash test data to the agency to demonstrate their compliance with the standard.

If you have any further questions, please let me know.

Sincerely,

BLUE BIRD BODY COMPANY

August 15, 1984

OCC-1058

Frank Berndt Chief Counsel National Highway Traffic Safety Administration

Dear Mr. Berndt:

Blue Bird Body Company is a major manufacturer of school and non-school buses which are sold throughout the U.S. and Canada. For years, on non-school buses, we have offered air conditioning as a regular option and have provided auxiliary fuel fired heaters upon request on a temporary option basis. The market place has recently been expressing a need for these features on school buses. We have received requests for auxiliary fuel fired heaters from several northern states and Canadian provinces. The need for auxiliary heating capability is increasing with the increased popularity of diesel powered school buses, which have less heat available for heating and defrosting of the driver and passenger compartments.

The demand for air conditioning in school buses is naturally coming from the warmer climate states, particularly Florida, and is primarily for lift buses used in transporting the handicapped. These vehicles often travel long routes and the stops to load and unload passengers are often quite lengthy. As a result the students often spend a lot of time on the bus and many of the special students are more sensitive to excessive heat than non-handicapped students.

I have presented this background and brief explanation because we at Blue Bird, strongly believe that the need for auxiliary heating and air conditioning on school buses is real and justified, and has significant bearing on the safety and well being of the students being transported. In order to provide these needed features on new school buses in an efficient and cost effective manner, we as body manufacturers must be able to install available heating and air-conditioning units and systems at the factory, and certify the completed vehicle as meeting all applicable Federal Motor Vehicle Safety Standards. The typical and commonly available auxiliary heating systems and air conditioning systems include fuel powered units mounted to the outside of the chassis frame and/or the underside of the body and located between the outside of the chassis frame and the outside body sheetmetal, or skirt, as it is commonly called. With the variety of systems available that could be requested by the customer, the different sizes, types, and configurations of vehicles that are involved and the variety of possible mounting locations on each type vehicle, the combinations of equipment involved is potentially quite large. Our primary concern is with FMVSS 301-75 as it applies to school buses and auxiliary equipment provided on school buses that have their own fuel systems.

It is our understanding that FMVSS 301-75 as it applies to school buses with GVWR's of more than 10,000 pounds is a vehicle performance standard, and that the vehicle, including any and all auxiliary equipment installed on the vehicle, must meet FMVSS 301-75 requirements and be certified as meeting FMVSS 301-75. In other words, if we choose to manufacture and sell school buses with an auxiliary heater or air conditioner mounted in the skirt such that it could be impacted by the moving contoured barrier as specified in Section S6.5, we would need to be sure that the fuel system of the auxiliary heater or air conditioner would not cause the vehicle to exceed the fuel spillage requirements of S5.5 and be capable of documenting our compliance. We request your confirmation that the fuel system of an auxiliary heater or air conditioner installed on a new school bus is covered by FMVSS 301-75, and that there are no exemptions or interpretations that exclude such systems from the standard's requirements.

Due to the variety of systems and combinations discussed previously and the continual evolution of chassis, body and heater/air conditioner designs and manufacturing procedures, we feel it is impractical and economically prohibitive to conduct full scale vehicle crash tests. We, therefore, wish to pursue alternate methods of certification documentation. One particular system we have looked at is a skirt mounted air conditioner with a diesel engine. The diesel fuel system of the vehicle is certified as meeting FMVSS 301-75. The engine on the air conditioner shares the same fuel tank as the vehicle's engine and, thus, only the fuel lines, fuel pump, filler filter, and the air conditioner's engine itself pose a concern relating to FMVSS 301-75 compliance. Preliminary tests have shown the air conditioner fuel system contains only about 3 1/2 ounces of fuel and the fuel pump is controlled by an oil pressure switch on the air conditioner's engine. We feel that by locating the fuel pump and fuel filter inside the chassis frame where they are extremely well protected, and by using high quality flexible fuel lines carefully routed and supported to prevent them from being damaged, we can easily maintain assurance of compliance with FMVSS 301-75. On such a system, would the agency accept Engineering documentation in the form of drawings. Engineering instructions, and Quality Assurance procedures in lieu of actual crash test reports as a suitable basis for certification? Would it be necessary or desirable to have independent laboratory inspection and approval under such a method of certification? Are any manufacturers using this type of certification, and if so, could we be provided with examples of the documentation used?

Blue Bird Body Company believes in its motto that, "Your Children's Safety is Our Business". Blue Bird also believes in improving its products, providing the safest, most modern and most efficient products possible, and in meeting our customer's needs whenever possible. To this end we appreciate any assistance the agency can provide to enable us to offer auxiliary heaters and air conditioning on new school buses. I have taken the liberty of sending three copies of this letter to Mr. Francis Armstrong and to Mr. Ralph Hitchcock, since I feel input from both Enforcement and Rulemaking would be beneficial in addressing this issue.

Thank you very much for your consideration of this matter.

Thomas D. Turner Manager Engineering Services

c: FRANCIS ARMSTRONG (3) -- OFC. OF VEHICLE SAFETY COMPLIANCE; RALPH HITCHCOCK (3) -- OFC. OF VEHICLE SAFETY STDS.