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NHTSA Interpretation File Search

Overview

NHTSA's Chief Counsel interprets the statutes that the agency administers and the standards and regulations that it issues. Members of the public may submit requests for interpretation, and the Chief Counsel will respond with a letter of interpretation. These interpretation letters look at the particular facts presented in the question and explain the agency’s opinion on how the law applies given those facts. These letters of interpretation are guidance documents. They do not have the force and effect of law and are not meant to bind the public in any way. They are intended only to provide information to the public regarding existing requirements under the law or agency policies.

Understanding NHTSA’s Online Interpretation Files

NHTSA makes its letters of interpretation available to the public on this webpage.

An interpretation letter represents the opinion of the Chief Counsel based on the facts of individual cases at the time the letter was written. While these letters may be helpful in determining how the agency might answer a question that another person has if that question is similar to a previously considered question, do not assume that a prior interpretation will necessarily apply to your situation.

Your facts may be sufficiently different from those presented in prior interpretations, such that the agency's answer to you might be different from the answer in the prior interpretation letter;
Your situation may be completely new to the agency and not addressed in an existing interpretation letter;
The agency's safety standards or regulations may have changed since the prior interpretation letter was written so that the agency's prior interpretation no longer applies; or
Some combination of the above, or other, factors.

Searching NHTSA’s Online Interpretation Files

Before beginning a search, it’s important to understand how this online search works. Below we provide some examples of searches you can run. In some cases, the search results may include words similar to what you searched because it utilizes a fuzzy search algorithm.

Single word search

Example: car
Result: Any document containing that word.

Multiple word search

Example: car seat requirements
Result: Any document containing any of these words.

Connector word search

Example: car AND seat AND requirements
Result: Any document containing all of these words.

Note: Search operators such as AND or OR must be in all capital letters.

Phrase in double quotes

Example: "headlamp function"
Result: Any document with that phrase.

Conjunctive search

Example: functionally AND minima
Result: Any document with both of those words.

Wildcard

Example: headl*
Result: Any document with a word beginning with those letters (e.g., headlamp, headlight, headlamps).

Example: no*compl*
Result: Any document beginning with the letters “no” followed by the letters “compl” (e.g., noncompliance, non-complying).

Not

Example: headlamp NOT crash
Result: Any document containing the word “headlamp” and not the word “crash.”

Complex searches

You can combine search operators to write more targeted searches.

Note: The database does not currently support phrase searches with wildcards (e.g., “make* inoperative”).

Example: Headl* AND (supplement* OR auxiliary OR impair*)
Result: Any document containing words that are variants of “headlamp” (headlamp, headlights, etc.) and also containing a variant of “supplement” (supplement, supplemental, etc.) or “impair” (impair, impairment, etc.) or the word “auxiliary.”

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NHTSA's Interpretation Files Search

Displaying 1261 - 1270 of 6047

Interpretations	Date

ID: nht78-1.14 Open DATE: 03/20/78 FROM: AUTHOR UNAVAILABLE; E. T. Driver; NHTSA TO: Alfred Teves GMBH TITLE: FMVSS INTERPRETATION TEXT: In your letter of June 23, 1977, to Mr. W. M. Radler, you asked if Federal Motor Vehicle Safety Standard (FMVSS) No. 106-74, Brake Hoses, would apply to a special hose assembly intended for use with your Hydrobooster system. The diagram you enclosed showed the hose assembly interconnecting the charging valve with the brake booster unit. Power steering fluid is fed through it under pressure. Your representative, Mr. Paul Utans, has presented two rubber hose assemblies in the recent past. On October 5, 1977, he submitted what we assume to be the design to be used with your Hydrobooster. It is stamped with the date 10/8/77. In the preamble to Notice 11, Docket 1-5, published June 24, 1974, (39 FR 24012) all power steering type hoses that connected power steering pumps with accumulators were exempted from the standard. Hoses connecting accumulators with boosters were also exempted if redundant boosters were provided. The National Highway Traffic Safety Administration (NHTSA) has reviewed this latter interpretation and determined that all power steering type hose should be exempt from FMVSS 106-74, whether or not redundant boosters are present. Brake power booster systems must meet the applicable performance requirements of FMVSS 105-76, "Hydraulic Brake Systems" which does not require a redundant booster. Further, the requirements in FMVSS 106-74 are not appropriate for power steering hoses. The interpretation in Notice 11 is therefore modified to permit the exemption of all power steering type hoses and tubing assemblies used with hydraulically operated brake power boosters until performance requirements for them are established. After consideration of the sample and the information you have supplied, we have concluded that the subject hose assembly must be classified as power steering hose. Consequently, your Hydrobooster hose assembly is considered exempt from coverage by FMVSS 106-74 until appropriate requirements for such hose assemblies can be included in the standard. A plastic tube assembly used in the same system would also be exempt. Sincerely, ATTACH. Welfred M. Redler, P.E. -- Office of Crash Avoidance, NHTSA June 23, 1977 Subj.: Request Dear Mr. Redler, for one of our customers, a central hydraulic system is being installed since the beginning of production of the 78 model range; the wiring diagram of this system is attached. The tube which is presently mounted between accumulator and hydrobooster is to be replaced before long by a plastic hose for reasons of noise transmissions. Mr. Utans has already informed you that we cannot use a rubber hose with the required dimensions (internal dia. 10 mm) for this specific purpose. Since, however, we are not sure about the requirements the hose will have to meet in the U.S.A., we kindly ask you to inform us about them. The following hose characteristics should be taken into consideration: a) When installed in the system, the hose must withstand a permanent pressure of 36 - 52 bar (522 - 754 psi). b) In the case of a failure of this hose, the system will still meet the requirements as per FMVSS 105-75, S 7.10. c) Since it is a plastic hose, the requirements as per FMVSS 106-74, S 6.3, Whip Test, cannot be met. However, we hold the view that this is not necessary since the hose is used as a connection for two units attached to the same vehicle part (frame) where no important vibrations will occur. As has been mentioned before, this hose will be exclusively used as a noise deadening hose. d) If, contrary to our expectations, you decide that our plastic hose is a hydraulic brake hose as defined by FMVSS 106-74, we should like to ask you to release us from the obligation to meet the requirements of sections 5.2 Identification and 6.3. Whip Test. When taking a decision, please bear in mind that similar hoses are presently installed in production vehicles in the U.S.A. Thanking you in advance for your kind assistance we remain, Yours sincerely, Alfred Teves GmbH P.P.9 (Graphics omitted) (Graphics omitted)
ID: 06-002774drn Open Ms. Amanda Reyes Daniel Boone & Company 1180 N. Fountain Way #B Anaheim, CA 92806 Dear Ms. Reyes: This responds to your letter concerning whether your motorcycle parts must meet the Federal Motor Vehicle Safety Standards (FMVSSs) applicable to motorcycles or any other National Highway Traffic Safety Administration (NHTSA) requirements. Our answer is provided below. As explained below, since your products are motor vehicle equipment, your company, Daniel Boone & Company, is subject to certain NHTSA requirements as the manufacturer of the equipment. NHTSA is authorized to issue Federal motor vehicle safety standards (FMVSSs) for new motor vehicles and new items of motor vehicle equipment. Unlike the practice in many countries, NHTSA does not provide approvals of motor vehicles or motor vehicle equipment. Instead, manufacturers are required to certify that their vehicles and equipment meet applicable standards. Billet Wheels Must Meet FMVSS No. 120, Tire Selection and Rims for Motor Vehicles with a GVWR of More than 4,536 Kilograms (10,000 Pounds) You write that your company manufactures billet wheels. FMVSS No. 120, Tire selection and rims for motor vehicles with a GVWR of more than 4,536 kg (10,000 pounds) applies to: motor vehicles with a gross vehicle weight rating (GVWR) of more than 10,000 pounds and motorcycles, to rims used on those vehicles, and to non-pneumatic tire spare tire assemblies for use on those vehicles. (See S3. Application.) Your billet wheels would be considered rims used on those vehicles (i.e., motorcycles). Thus, FMVSS No. 120 would apply to your billet wheels. Therefore, the billet wheel must be marked with the DOT symbol, as well as with other required information specified in S5.2. S5.2(c) of FMVSS No. 120 requires that the symbol DOT be stamped on the rim, which constitutes a certification by the manufacturer of the rim that the rim complies with all applicable motor vehicle safety standards. NHTSA does not assign a DOT number or identification mark for rim manufacturers. Since FMVSS No. 120 applies to billet wheels that your company manufactures, your company must also meet 49 CFR Part 566, Manufacturer Identification. Part 566 requires that a manufacturer of motor vehicles or motor vehicle equipment to which a motor vehicle safety standard applies, submit information identifying itself and its products to NHTSA not later than 30 days after it begins manufacture. This information must be mailed to the Administrator, National Highway Traffic Safety Administration, 400 Seventh St., S.W., Washington, D.C. A sample Manufacturer Identification Submission is attached. Forward Controls, Calipers and Rotors for Motorcycles are Motor Vehicle Equipment You also wish to know whether any FMVSSs apply to forward controls, calipers and rotors for motorcycles. The answer is no. NHTSA has FMVSSs applicable to motorcycles (i.e., FMVSS No. 122, Motorcycle brake systems, and FMVSS No. 123, Motorcycle controls and displays), but not to forward controls, calipers and rotors. However, since the parts your company manufactures are motor vehicle equipment, they are subject to various provisions of 49 U.S.C. Chapter 301, Motor Vehicle Safety. Motor vehicle equipment is defined at 49 U.S.C. Section 30102(a)(7) as: (A) any system, part, or component of a motor vehicle as originally manufactured; (B) any similar part or component manufactured or sold for replacement or improvement of a system, part, or component, or as an accessory or addition to a motor vehicle; or (C) any device or an article or apparel (except medicine or eyeglasses prescribed by a licensed practitioner) that is not a system, part, or component of a motor vehicle and is manufactured, sold, delivered, offered, or intended to be used only to safeguard motor vehicles and highway users against risk of accident, injury or death. Clearly, since the billet wheels, forward controls, calipers and rotors are parts of motorcycles as originally manufactured, or are sold as replacement parts of motorcycles, these parts are motor vehicle equipment. Manufacturers of motor vehicles and motor vehicle equipment must ensure that their products are free of safety-related defects. If the manufacturer or NHTSA should determine that a product contains a safety-related defect, the manufacturer is responsible for notifying NHTSA and purchasers of the defective equipment and remedying the problem free of charge. (See Title 49 of the Code of Federal Regulations, Part 573, Defect and Non-Compliance Responsibility and Reports.) In addition, the States regulate the use of vehicles and items of motor vehicle equipment. Each State in which you sell your products can provide information on whether there are any requirements in that State for the billet wheels, forward controls, calipers or rotors that are to be used with motorcycles. I am enclosing a copy of our July 2006 publication, Information for New Manufacturers of Motor Vehicles and Motor Vehicle Equipment. I hope this information is helpful. If you have any further questions, please feel free to contact Dorothy Nakama of my staff at this address or by telephone at (202) 366-2992. Sincerely, Anthony M. Cooke Chief Counsel Enclosure ref:VSA102(4) d.3/28/06	2006
ID: nht79-3.6 Open DATE: 08/27/79 FROM: AUTHOR UNAVAILABLE; Frank Berndt; NHTSA TO: Mr. Bruce Willhite TITLE: FMVSS INTERPRETATION TEXT: This is in response to the questions you raised with Ms. Debra Weiner of my office on June 29, 1979, about your intention to start a business that will sell and install auxiliary diesel fuel tanks in passenger cars. You noted that you would like to install the tanks in used vehicles and possibility in new ones. Specifically, you asked what Federal law applies to your proposed activities and whether these activities would violate any Federal law. The National Traffic and Motor Vehicle Safety Act of 1966, as amended, (the Act) authorizes the National Highway Traffic Safety Administration (NHTSA) to issue Federal Motor Vehicle Safety Standards (FMVSS's) applicable either to vehicles or to equipment for installation in vehicles. FMVSS 301-75, Fuel System Integrity, (see enclosed copy) is a vehicle standard which applies to vehicles, including passenger cars, which use fuel with a boiling point above 32 degrees F. (this includes both gasoline and diesel fuel). Under section 108(a)(1)(A) and (b)(1) of the Act, new motor vehicles must comply with the FMVSS's applicable to them until they are first purchased by someone for purposes other than resale. That purchase is completed when the vehicle is delivered to the ultimate consumer. The NHTSA regulations include two measures designed to ensure compliance with applicable FMVSS's until this delivery. First, manufacturers of new vehicles are required to affix to each vehicle they produce a label which certifies the vehicle's compliance with all applicable FMVSS's. Second, any person who prior to the first sale, alters a certified vehicle in a manner that significantly affects either its configuration or purpose is considered to be not only an alterer but also a manufacturer and therefore, must recertify the entire vehicle as complying with all applicable FMVSS's. (49 Code of Federal Regulations (C.F.R.) 567.7). Should a noncompliance due to an alterer's modification be discovered in a recertified vehicle, the alterer would be liable for a civil penalty unless he or she could establish that he or she did not have actual knowledge of the noncompliance, and that he or she did not have reason to know in the exercise of due care that the vehicle did not comply. (Section 108(b)(2) of the Act.) The civil penalty imposed could be up to $ 1000 for each violation of an applicable FMVSS. (Section 109 of the Act.) Since the installation of an auxiliary fuel tank significantly affects the configuration of an automobile, the legal provisions summarized above would apply to you as an installer of auxiliary fuel tanks in new cars (i.e., cars not yet purchased for purposes other than resale and delivered to that purchaser). Thus, upon installing an auxiliary fuel tank in a new vehicle you would be required to affix a label to the vehicle stating that the vehicle as altered conforms to all applicable FMVSS's including FMVSS 301-75 in effect on a date not later than the date on which the alterations were completed (49 C.F.R. Part 567.7). This means that not only must the original gasoline fuel system meet the performance requirements encompassed by FMVSS 301-75 but that the system as supplemented by the auxiliary tank added by you to a new car must meet them also. As an installer of auxiliary fuel tanks in new vehicles, you will also be subject to the provisions of sections 151 et seq. of the Act (see enclosure). If you or this agency finds that there is a safety defect in the manner in which you have installed auxiliary tanks in new vehicles, you would be required to notify purchasers and remedy the defect. Under sections 108(a)(1)(D) and 109(a) of the Act, any person who fails to provide notification of or remedy for a safety defect is liable for a civil penalty of up to $ 1000 per violation. As a dealer in and installer of auxiliary fuel tanks in used vehicles, you would be subject to section 108(a)(2)(A) of the Act. Section 108(a)(2)(A) in essence prohibits the entities and persons listed below from knowingly removing, disconnecting or reducing performance of equipment or elements of design installed on a vehicle in accordance with applicable FMVSS's. There is no prohibition against an individual person modifying his or her own vehicle. Specifically, the section provides: No manufacturer, distributor, dealer or motor vehicle repair business shall knowingly render inoperative, in whole or part, any device or element of design installed on or in a motor vehicle or item of motor vehicle equipment in compliance with an applicable Federal motor vehicle safety standard . . . A person or entity found to have violated this section would be liable for a civil penalty of up to $ 1000 for each violation. (Section 109 of the Act.) If one of the persons or entities listed above adds an auxiliary gasoline tank to a vehicle manufactured in accordance with FMVSS 301-75, and in the process knowingly reduces the performance of the fuel system originally installed in the motor vehicle, he or she has violated section 108(a)(2)(A). (H.R. No. 1191, 93d Cong., 2d Sess. 34 (1974)). Such reduction of performance could occur, for example, if gasoline from the original system (a fuel system includes the filler pipe, tank, gasoline lines, fuel pump, carburetor, and engine) could be leaked through a rupture in the auxiliary tank and fuel lines, and if the design, materials, construction, installation or location of the auxiliary tank and fuel lines made them more susceptible to rupture than the original fuel system. In closing, I would like to point out that, in addition to the Federal law discussed above, there may be State products liability laws applicable to your proposed activities. As an installer of auxiliary fuel tanks, you could be liable for the manner and location in which the tanks are installed. Therefore, you may wish to consult a local lawyer before starting your new business. I hope that you will find this response helpful.
ID: 11-004197 Kiddy USA belt guide -shield cracks -atd lift (Std 213) Open Ms. Katherine Hubanks Director of Sales Kiddy USA 2420 Wild Iris Lane Dacula, GA 30019 Dear Ms. Hubanks: This responds to your May 31, 2011 letter asking about Federal Motor Vehicle Safety Standard (FMVSS) No. 213, Child Restraint Systems. You explain that Kiddy USA (Kiddy) is a new manufacturer from Germany of childrens car seats setting up distribution in the United States. We understand from your letter that the manufacturer has had one or more of its child restraint systems (CRSs) tested at a U.S. test laboratory according to the test procedures of FMVSS No. 213. You enclose correspondence from an associate who asks whether eight test outcomes conform to FMVSS No. 213. By way of background, the National Highway Traffic Safety Administration (NHTSA) does not approve motor vehicles or motor vehicle equipment, including child restraints, and does not make determination as to whether a product conforms to the FMVSSs outside of an agency compliance test. Instead, the National Traffic and Motor Vehicle Safety Act (49 U.S.C. 30101 et seq.) sets forth a self-certification process, in which each manufacturer is responsible for certifying the compliance of its products. Manufacturers are also responsible for ensuring that their products are free of safety-related defects. The following interpretation of FMVSS No. 213 is based on the information provided in your letter, and could change if information becomes available that indicates that the information upon which this letter is based is not as we had understood. Also, we do not affirm that the test you conducted conforms to FMVSS No. 213s procedures. Please note that, if we do not comment on an aspect of performance of your CRS shown in your letter, this does not mean we believe a requirement does not apply or that your product would meet the requirement. Further, we note also that our answers to your questions are somewhat limited by the fact that your questions consisted mainly of photographs and almost no discussion. 1. Kiddys first question asks: Cracks on screw anchorage of torso shield belt guide --is this conform [sic]? One of the photographs appears to show a 3-year-old child test dummy in a CRS with a torso shield. A Type 1 belt is routed over the shield. Another photograph shows a close-up of the cracks, which are on the underside of the shield, the side not facing the test dummy. Answer: S5.1.1 and S5.1.1(a) of FMVSS No. 213 apply to this situation. S5.1.1 and S5.1.1(a) state: S5.1.1 Child restraint system integrity. When tested in accordance with S6.1, each child restraint system shall meet the requirements of paragraphs (a) through (c) of this section. (a) Exhibit no complete separation of any load bearing structural element and no partial separation exposing either surfaces with a radius of less than inch or surfaces with protrusions greater than 3/8 inch above the immediate adjacent surrounding contactable surface of any structural element of the system. * * * * * S5.1.1(a) prohibits any complete separation of any load bearing structural element, which would include the torso shield. In the photographs you provided, it is difficult to see the cracks, but it does not appear that the cracks constitute a complete separation. Also, the cracks do not appear to be on a contactable surface,[1] so the prohibitions of S5.1.1(a) against sharp edges or protrusions does not appear to apply. Accordingly, it appears that the cracks do not violate S5.1.1(a). 2. Kiddy asks: Lifting of headrest during crash test by top tether because of cracking of head rest adjust area--is this conform [sic]? A 12-month-old child test dummy was used in the test. A Type 1 belt and top tether were used with the CRS. Answer: S5.1.1(b)(1) of FMVSS No. 213 states: S5.1.1(b)(1) If adjustable to different positions, remain in the same adjustment position during the testing that it was in immediately before the testing, except as otherwise specified in paragraph (b)(2). This requirement is intended to prevent a childs fingers or limbs from being caught between shifting parts of the CRS, and to prevent a childs sliding too far forward and downward (submarining) during a crash. In a September 4, 1996 letter to Mr. C. Scott Talbot, NHTSA interpreted the requirement as intending to prevent injuries caused by the repositioning of the seating surface of the restraint (i.e., the reclining feature). In view of these considerations, we conclude that S5.1.1(b)(1) does not prohibit the head restraint from moving up. However, on a different matter, it is not clear from your letter where the cracking of the head rest adjust area occurred, i.e., whether the cracking was to a load bearing structural element or to a contactable surface. Under S5.1.1(a), if the cracking was to a load bearing structural element--and we believe this area could qualify as such--there must not be any complete separation of the load bearing structural element. It was difficult to see the cracks in the photograph so we were unable to tell from the photograph if there was a complete separation. If the cracking was to a contactable surface, there must not be any cracks exposing sharp edges or surfaces with protrusions greater than 3/8 inch above the immediate adjacent surrounding contactable surface. It appears from the photograph that a screw may have been protruding above the surrounding area. We cannot determine from the photograph whether this area was a contactable surface, or the height of the protrusion. 3. Kiddy asks: [R]etainment of 12 month Crabby [sic] (Dummy stood up slightly)--is this conform [sic]? The dummy was in a forward-facing child seat. Answer: S5.1.3 and S5.1.3.1 of FMVSS No. 213 state: S5.1.3 Occupant excursion. When tested in accordance with S6.1 and the requirements specified in this section, each child restraint system shall meet the applicable excursion requirements specified in S5.1.3.1-S5.1.3.3. S5.1.3.1 Child restraint systems other than rear-facing ones and car beds. Each child restraint system, other than a rear-facing child restraint system or a car bed, shall retain the test dummys torso within the system. * * * * * Torso is defined (S4) in FMVSS No. 213 as: the portion of the body of a seated anthropomorphic test dummy, excluding the thighs, that lies between the top of the child restraint system seating surface and the top of the shoulders of the test dummy. From the photograph you provided, we cannot determine the location of the dummys shoulders relative to the child restraint when the dummy stood up slightly. 4. Kiddy asks: Cracks at torso shield belt guide--is this conform [sic]? This test involved a CRS tested with a 3-year-old child test dummy. Answer: Our answer is similar to our answer to question 1. S5.1.1(a) prohibits any complete separation of any load bearing structural element, which would include the torso shield. It is difficult to see the photographs you provided, and we cannot determine if the cracks constitute a complete separation. The cracks do not appear to be on a contactable surface since they are on the underside of the shield. 5. Kiddy asks: Belt guide connection to the head rest breaks/but belt guide remains at head rest because of screw contact to metal support inside--is this conform [sic]? This was a test of the CRS in a booster mode with a 6-year-old child test dummy in a Type II belt. Answer: Is the belt guide a load bearing structural element? We cannot tell from the photograph you sent. Generally, webbing guides that only position the seat belt webbing for the users comfort and that do not have structural benefit for the performance of the CRS or vehicle belt performance are not considered a structural part of the seat. As such, the prohibition of S5.1.1(a) would not apply. If the belt guide is a load bearing structural element, S5.1.1(a) would prohibit the breaking you describe. 6. Kiddy asks: [B]elt guide has damaged the safety belt--is this conform [sic]? The photograph shows a substantial rip in the shoulder belt webbing. We assume the damage occurred in the dynamic test. Answer: Manufacturers must ensure that their child restraints are free of safety-related defects. The ripping of the seat belt by the belt guide raises a concern about a possible safety-related defect of the CRS. If data indicated that the damaged seat belt exposed occupants to an unreasonable risk of injury, NHTSA might conduct a defect investigation which could lead to a safety recall. 7. Kiddy asks: Opening and cracking on belt guide hook located on the head rest--is this conform [sic]? The photograph shows the buckle position clip broken off. Answer: Our answer is the same as our answer to question 5. If the belt guide is a load bearing structural element, S5.1.1(a) would prohibit the breaking you describe. 8. Kiddy asks: Belt guide connection to the head rest breaks/but belt guide remains at head rest because of screw contact to metal support inside--is this conform [sic]? Notations indicate that this test is with the HIII 5^thFemale. Answer: FMVSS No. 213 does not specify testing with the Hybrid III 5^th percentile adult female, so we are not sure of the context of your question. If you are asking whether the belt guides breaking is permitted under FMVSS No. 213 in an FMVSS No. 213 test, see our answer to question 5. Procedural Regulations I would like to draw your attention to two procedural regulations of which manufacturers should be aware to import child restraints into the United States. The first is 49 CFR Part 566, Manufacturer Identification. This regulation requires a manufacturer of motor vehicle equipment subject to the FMVSSs to submit its name, address, and a brief description of the equipment it manufactures to this agency within 30 days of the date the equipment is first manufactured. The second regulation is 49 CFR Part 551, Procedural Rules. Section 551.45 requires the manufacturer of foreign‑manufactured child restraints to designate a permanent resident of the United States as the manufacturer's agent for service of process in this country. The regulation specifies the items needed for a valid designation. I hope this information is helpful. For your information, I have enclosed a brief information sheet for new manufacturers. If you have any further questions, please contact Ms. Deirdre Fujita at (202) 366-2992. Sincerely yours, O. Kevin Vincent Chief Counsel Enclosure 11/28/2011 [1] FMVSS No. 213 (S4) defines contactable surface as: any child restraint system surface (other than that of a belt, belt buckle, or belt adjustment hardware) that may contact any part of the head or torso of the appropriate test dummy, specified in S7, when a child restraint system is tested in accordance with S6.1.
ID: 08-003686as 1 Open Mr. Mark Temple Bikers of Lesser Tolerance 8790 Mellowdawn Way Orangevale, CA 95662 Dear Mr. Temple: This responds to your letter asking several questions related to motorcycle helmets and the testing required to certify to Federal Motor Vehicle Safety Standard (FMVSS) No. 218, Motorcycle Helmets. We have addressed your questions below. By way of background, the National Highway Traffic Safety Administration (NHTSA) is authorized to issue FMVSSs that set performance requirements for new motor vehicles and items of motor vehicle equipment (see 49 U.S.C. Chapter 301). NHTSA does not provide approvals of motor vehicles or motor vehicle equipment. Instead, manufacturers are required to self-certify that their products conform to all applicable safety standards that are in effect on the date of manufacture. NHTSA selects a sampling of new vehicles and equipment each year to determine their compliance with applicable FMVSSs. If our testing or examination reveals an apparent noncompliance, we may require the manufacturer to remedy the noncompliance, and may initiate an enforcement proceeding if necessary to ensure that the manufacturer takes appropriate action. You first ask if there has been a change in the Federal regulation regarding the certification process for motorcycle helmets in the last 10 years. On October 2, 2008, NHTSA published a notice of proposed rulemaking (NPRM) in the Federal Register proposing to update the testing procedures and labeling requirements of FMVSS No. 218. A copy of the NPRM is enclosed. Your second question asks if the Department of Transportation (DOT) certifies motorcycle helmets. As explained in the background paragraph to this letter, NHTSA does not provide approval (or certification) of motor vehicle equipment (a motorcycle helmet is considered motor vehicle equipment). Instead, we require that manufacturers certify that new motor vehicle equipment they produce complies with all applicable FMVSSs. Your third question asks for clarification as to what is DOT-certified helmet. DOT-certified helmet commonly means a helmet that has been certified by its manufacturer as meeting all requirements of FMVSS No. 218. Fourth, you ask if, short of testing as specified in FMVSS No. 218, there is any way to determine if the helmet will pass FMVSS No. 218. To assess a products conformance to the Federal motor vehicle safety standards, NHTSA follows the test procedures specified in the applicable standard. Additionally, more detailed testing procedures that NHTSA-contracted laboratories use to test compliance are available on NHTSAs website. We do not require manufacturers to test their products in the manner described in the standard, but they must ensure that their product will meet the specified performance requirements when tested by NHTSA in the manner set forth in the standard. Your next question asks why helmets are subjected to expensive and rigorous scientific testing if there is another, possibly less expensive method to determine compliance with FMVSS No. 218. Our performance tests are designed to be reasonable, practicable and objective. If you believe that NHTSAs testing requirements can be made less expensive and that adequate testing of the safety considerations can be met through less burdensome means, you are welcome to submit those ideas with supporting documentation to the agency. Your final question asks if we are aware of any State enforcement agency that cites an end user/consumer of FMVSS regulated products for the use of a recalled product, other than motorcycle helmets? By recalled product, we assume you mean a product that does not meet applicable standards. For answers about specific State laws, you should direct your question to the State departments administering motor vehicle regulations. We do note that State agencies have the authority and the responsibility to regulate the use of motor vehicle and motor vehicle equipment, ensuring motorists and taxpayers in their jurisdictions are protected to the best of the States ability. States have sought to optimize the safety of motorists by requiring the use of safety equipment, e.g., seat belts, child safety seats, see-through windows, motorcycle helmets, tires, and by specifying that the equipment be certified to the FMVSSs. NHTSA strongly recommends the use of such equipment, as equipment meeting the FMVSSs reduce the risk of involvement in a crash, the severity of injury or the likelihood of death in a crash. If you have any further questions, please contact Ari Scott of my staff at (202) 366-2992. Sincerely yours, Anthony M. Cooke Chief Counsel Enclosure ref:218 d.11/20/08	2008
ID: 09-008024ws Yuen Open Derek Yuen X-Test, Inc. 2480 Precision Drive, Suite A Minden, NV 89423 Dear Mr. Yuen: This responds to your letter, dated October 9, 2009, asking whether the motorcycle rear lamp system you describe is permissible under Federal Motor Vehicle Safety Standard (FMVSS) No. 108, which governs lamps, reflective devices, and associated equipment on vehicles. I sincerely apologize for the delay in this response. As explained below, we believe that the system would be permissible under FMVSS No. 108. By way of background, NHTSA is authorized by the Safety Act to issue FMVSSs that set performance requirements for new motor vehicles and new items of motor vehicle equipment. NHTSA does not provide approvals of motor vehicles or motor vehicle equipment. Instead, manufacturers are required to self-certify that their products conform to all applicable safety standards that are in effect on the date of manufacture. NHTSA selects a sampling of new vehicles and equipment each year to determine their compliance with applicable FMVSSs. If our testing or examination reveals an apparent noncompliance, we may require the manufacturer to remedy the noncompliance, and may initiate an enforcement proceeding if necessary to ensure that the manufacturer takes appropriate action. NHTSA also investigates safety-related defects. The following is our interpretation of the Safety Act and the FMVSSs based on the description contained in your letter. You describe the lamp system as consisting of two lamps, with one lamp located on either side of the rear vertical centerline of the motorcycle. The lamps are separated by a distance of 300 mm (11.8 in). Each of the lamps functions as turn signal, stop lamp, and taillamp. You indicate that the system has four functional modes: 1) Both lamps continuously illuminated as taillamps when the vehicle is on; 2) Both lamps illuminated at a higher intensity as stop lamps when the brakes are applied; 3) One lamp flashing as a turn signal while the other lamp remains continuously illuminated as a taillamp; and 4) In a situation where the brakes are applied at the same time as a turn is indicated, one lamp flashing as a turn signal while the other lamp remains continuously illuminated at a higher intensity. You also submitted diagrams showing two configurations of this system using lamps with different effective projected luminous lens areas (EPLLA). In the first configuration (No. 1), each of the two lamps has an EPLLA of 25.5 cm²(3.96 in²). In the second configuration (No. 2), each of the lamps has an EPLLA of 50.3 cm²(7.8 in²). You ask whether either of these configurations would be permissible under FMVSS No. 108. In particular, you express concern as to whether the first configuration would meet the EPLLA requirements for a stop lamp because, in Functional Mode No. 4, only one of the two lamps would be illuminated as a stop signal. As you indicate in your letter, FMVSS No. 108 requires a motorcycle to have one stop lamp but permits it to have two stop lamps symmetrically disposed about the vertical centerline. A motorcycle is also required to have two rear turn signal lamps, one on each side of the vertical centerline, with at least 9 inches separating the lamps. FMVSS No. 108 requires that the stop lamps must meet the requirements of Society of Automotive Engineers (SAE) Standard J586, revised February 1984, and that the rear turn signal lamps must meet the requirements of SAE J588, revised November 1984. The SAE standards permit the use of multiple compartment lamps or multiple lamps to meet the photometric requirements for stop lamps. The compartments or lamps in such systems are tested together as a unit so long as all the compartments or lamps are within a certain distance of each other. For a two-lamp system, the lamps must be within 560 mm of each other to be tested as a unit. In previous interpretation letters addressing rear motorcycle lamp configurations, we have applied the distance requirements in the SAE standards to conclude that lamp systems consisting of lamps on either side of the rear vertical centerline can be considered single lamps for the purposes of meeting the stop lamp photometric requirements (See enclosed November 20, 1998 letter to Tadashi Suzuki). In addition to the requirements contained in the SAE standards, FMVSS No. 108 states that [i]f a multiple compartment lamp or multiple lamps are used to meet the photometric requirements for stop lamps . . . the effective projected luminous lens area of each compartment or lamp shall be at least 22 square centimeters, provided the combined area is at least 50 square centimeters. However, each motorcycle rear turn signal lamp is only required to have an EPLLA of 22.58 cm² (3.5 in²). In your letter, the Configuration No. 1 lamp system consists of two lamps located 300 mm (11.8 in) apart, each of which has an EPLLA of 25.5 cm², for a combined EPLLA of 51 cm². Accordingly, we believe that this system would meet the EPLLA requirements for a single stop lamp and two motorcycle rear turn signal lamps. In response to your specific question, FMVSS No. 108 explicitly contemplates the optical combination of stop lamps and turn signal lamps. Therefore, we would not consider the stop lamp system to be noncompliant because only one of the lamps would function as a stop signal when a turn signal is flashing. Likewise, we believe that the Configuration No. 2 lamp system, which consists of two lamps with individual EPLLAs of 50.3 cm², would meet the EPLLA requirements for two stop lamps and two motorcycle rear turn signal lamps. However, the Configuration No. 1 lamp system raises another issue that we would like to address regarding the optical combination of the stop lamp and turn signals. The SAE standards state that when a stop lamp is optically combined with a turn signal lamp, the circuit shall be such that the stop signal cannot be turned on if the turn signal is flashing. FMVSS No. 108 adopts the definition of optically combine found in SAE J387, revised November 1987. Under the SAE definition, optical combination results when 1) a lamp has two or more separate light sources, or a single light source that operates in different ways (e.g., a two-filament bulb), and 2) the lamps optically functional lens area is wholly or partially common to two or more lamp functions. In the Configuration No. 1 lamp system, both lamps together constitute the required single stop lamp, and each individual lamp also acts as a turn signal. Under the definition stated above, the single stop lamp (consisting of both lamps) could be considered to be optically combined with both turn signals. Such an interpretation would mean that Functional Mode No. 4, where one lamp flashes as a turn signal while the other lamp remains continuously illuminated as a stop signal, would not be permissible. Neither of the lamps could be illuminated as a stop signal if one of the turn signals is flashing. In other words, the vehicle would display no signal indicating that the brakes were being applied in such a situation. In light of these consequences, we do not believe that such an interpretation of the term optically combine is appropriate for the unique situation presented by the lamp system you describe. Instead, we conclude that Functional Mode No. 4 is permissible under FMVSS No. 108. In that mode, the lamp that is flashing as a turn signal ceases operating as a stop signal. Nevertheless, the lamp system would continue to signal when the brakes are applied because the other lamp continues to operate as a stop signal. We caution that this interpretation is limited to the unique motorcycle rear lamp system described in your letter. I hope this information is helpful. If you have further questions, please contact William Shakely of my staff at (202) 366-2992. Sincerely, O. Kevin Vincent Chief Counsel Enclosure ref: Standard No. 108 7/26/11
ID: Ponziani Open Mr. Richard L. Ponziani President RLP Engineering 1958 Home Path Court Centerville, OH 45459 Dear Mr. Ponziani: This responds to your letter requesting clarification regarding how Federal Motor Vehicle Safety Standard (FMVSS) No. 108, Lamps, Reflective Devices, and Associated Equipment, applies to your product, which is referred to as an Electronic Intelligent Turn Signal System in the technical paper accompanying your letter. You described your product as a turn signal system that uses existing vehicle computers and wheel speed sensors to determine a situation appropriate shut off point, which you believe offers a safety improvement over current, mechanical turn signal operating units on passenger vehicles. Your letter stated that by combining steering wheel angle and steering wheel rotation data with other measures such as vehicle yaw and travel distance, your system may prevent instances of turn signal miscommunication, thereby increasing safety. Specifically, you cited examples in which the driver jars the steering wheel and the turn signal shuts off prematurely or lane change maneuvers where the steering wheel rotation is not sufficient to trigger turn signal cancellation. Although we have not examined your product, based on the information you have provided to the agency and the analysis below, we have concluded that your product would comply with the standard, provided that all of the other requirements of FMVSS No. 108 related to turn signals continue to also be met. By way of background, the National Highway Traffic Safety Administration (NHTSA) is authorized to issue FMVSSs that set performance requirements for new motor vehicles and items of motor vehicle equipment (see 49 U.S.C. 30111 and 49 CFR Part 571). NHTSA does not provide approvals of motor vehicles or motor vehicle equipment. Instead, manufacturers are required to self-certify that their products conform to all applicable safety standards that are in effect on the date of manufacture, before they can be offered for sale (see 49 U.S.C. 30115 and 49 CFR Part 567). FMVSS No. 108 sets forth the requirements for both new and replacement motor vehicle lighting equipment. NHTSA selects a sampling of new vehicles and equipment each year to determine their compliance with applicable FMVSSs. If our testing or examination reveals an apparent noncompliance, we may require the manufacturer to remedy the noncompliance, and may initiate an enforcement proceeding if necessary to ensure that the manufacturer takes appropriate action. Our statute (49 U.S.C. 30101 et seq.) prohibits any person from selling any new vehicle that does not comply with all applicable Federal safety standards (see 49 U.S.C. 30112). After the first sale of the vehicle, manufacturers, distributors, dealers, and repair businesses are prohibited from knowingly making inoperative any device or element of design installed on or in a motor vehicle in compliance with an applicable FMVSS. In general, the make inoperative prohibition (49 U.S.C. 30122) requires businesses that modify motor vehicles to ensure that they do not remove, disconnect, or degrade the performance of safety equipment installed in compliance with applicable standards. The make inoperative provision does not apply to owners modifying their own vehicles, but we urge owners not to degrade the safety of their vehicles. Turning to the specific issues raised by your letter, FMVSS No. 108 sets forth requirements for turn signal lamps in light vehicles. First, Table 3, Required Motor Vehicle Lighting Equipment, of FMVSS No. 108 specifies that each passenger car, motorcycle, multipurpose passenger vehicle (MPV), truck, bus, and trailer of less than 80 inches (2032 mm) in overall width must be equipped with two amber turn signals at or near the front of the vehicle and two red or amber turn signals at or near the rear of the vehicle (note that trailers only require two red or amber turn signals to the rear); Table 3 also requires those vehicles (other than trailers) to be equipped with a turn signal operating unit[1] and a turn signal flasher. Standard No. 108 also specifies other turn signal lamp requirements, including ones pertaining to location, dimensions, and photometric output. However, we will not discuss those provisions in detail, because your submissions do not suggest that your product would impact these characteristics of the turn signals, but would instead be limited to their operation (i.e., the point at which the turn signal would be switched off in the course of a turning maneuver). The provision of particular relevance here is paragraph S5.1.1.5 of FMVSS No. 108, which provides: The turn signal operating unit on each passenger car, and multipurpose passenger vehicle, truck, and bus less than 80 inches in overall width shall be self-canceling by steering wheel rotation and capable of cancellation by a manually operated control. As we pointed out in an April 2, 1986 letter of interpretation to Mr. Jacques Delphin, there are no performance requirements for the self-cancelling feature, so the agency concluded that the aftermarket device in question which cancels turn signal indicators immediately upon the completion of a turn would not impair the effectiveness of the turn signal operating unit or create a noncompliance with Standard No. 108. However, in a May 30, 1997 letter of interpretation to Mr. Reggie Lawrence, we concluded that an aftermarket Blinker Delay System that would prevent the automatic cancellation of the turn signal system for three to four seconds after the front wheels of a towing vehicle have been straightened (to indicate that a turn has not been completed) would create a noncompliance with Standard No. 108, by defeating the vehicles attempt to self-cancel the turn signals operation by steering wheel rotation. These letters are consistent in light of the provision in paragraph S5.1.3 of the standard, which provides, No additional lamp, reflective device or other motor vehicle equipment shall be installed that impairs the effectiveness of lighting equipment required by this standard. Thus, an aftermarket device which accelerates self-cancellation of turn signal operation immediately after a turn is consistent with the standard, but one which delays self-cancellation is not. However, if your product is an original equipment (OE) turn signal system, which provides a control unit with a complete logic for self-cancelling turn signal operation (as compared to a supplemental system which changes the operation of an existing system), we conclude that it would be permissible under FMVSS No. 108. As described, your system evaluates driver steering inputs, as well as a variety of other information provided by vehicle wheel speed sensors, to determine the appropriate point for turning off the turn signal. (We note that your technical paper also states that your system would include a button allowing the driver to cancel the turn signal event at any time, thereby meeting the second requirement of paragraph S5.1.1.5.) Therefore, because the standard does not specify precisely when cancellation must occur (and based on our understanding that steering wheel rotation would be a triggering element each time the system does cancel the turn signal), we conclude that an OE Electronic Intelligent Turn Signal System as you have described would meet the requirements of FMVSS No. 108, provided that all of the standards other relevant requirements for turns signal are met. If you have further questions, please feel free to contact Eric Stas of my staff at this address or by telephone at (202) 366-2992. Sincerely, Anthony M. Cooke Chief Counsel ref:108 d.3/22/07 [1] A turn signal operating unit is defined as that part of a turn signal system by which the operator of a vehicle causes the signal units to function (see Society of Automotive Engineers (SAE) standard SAE J589, Turn Signal Operating Units (rev. April 1964). Table 3 of FMVSS No. 108 incorporates SAE J589 (rev. April 1964) by reference, which includes a durability test for the turn signal system.	2007
ID: nht92-3.41 Open DATE: September 24, 1992 FROM: C. Morris Adams TO: Paul Jackson Rice -- Chief Counsel, NHTSA COPYEE: Paula Hanna -- Exec. Sec., NAPT; Charles Gauthier -- MVSS Compliance Section, NHTSA TITLE: None ATTACHMT: Attached to letter dated 10/1/92 Est. from Paul Jackson Rice to C. Morris Adams (A40; Std. 222) TEXT: I retired from Thomas Built Buses, Inc. in December 1990, after 45 years of service to the school transportation industry in North America. Although I retired, I remain totally committed to and interested in school transportation safety for our children. During the last seven years of my career, I spent a very large percentage of my efforts in behalf of our children by educating our people and regulatory agencies on the pros and cons of lap belts vs. compartmentalization in school buses. The overwhelming evidence is in support of compartmentalization as mandated by NHTSA. New York state and New Jersey along with some local districts are mandating lap belts in addition to NHTSA mandated compartmentalization. Therefore, the purpose of this letter of request for a legal ruling from your office as to the legality of lap belts on school buses that are required by federal regulation to utilize the passive restraint system - compartmentalization. FMVSS 222 has as its intent the prevention of passengers colliding with dangerous objects inside the bus. Compartmentalization relies upon specially designed energy absorbing passenger seat systems (structure, padding, flexibility spacing) to provide the spreading of energy forces over a large percentage of the child's body upon impact with the seat and/or barrier immediately in front of the passenger. School bus manufacturers build and certify in compliance with FMVSS 222. If lap belts are required by the purchaser, they are installed. At this point in the process there seems to be no problem for anyone involved. However - The beneficial purpose of FMVSS 222 has now been removed. Once the lap belt is applied to the child, the child's body pivots around the belt and the head will come into contact with the seat back or barrier in front of the child. In addition to violent head injuries, possible pelvic and abdominal injuries or fatalities may result. The impact energy forces no longer are spread over the upper torso and upper thighs. Therefore, the intent of FMVSS 222 is no longer attainable even though the bus was built and certified to comply with the "technical" requirements of FMVSS 222. The addition of the lap belt or a lap bar restraint rendered compartmentalization null and void. If the seats are allowed to be spaced so that when the child pivots around the lap restraint the head will not contact the forward seat back or barrier, the beneficial intent of FMVSS 222 is still violated. In addition, wider spacing would reduce passenger capacity. Wider spacing of seats would destroy compartmentalization and should the child passenger not have the belt fastened, then the child could become a flying missile with no designed compartment to restrain it. Based upon the above data I strongly believe lap belts or restraining bars violate the beneficial intent of FMVSS 222 and should be ruled illegal in use on school buses required to meet FMVSS 222. In the interest of the 23 million pupils transported daily in safe school buses, I respectfully request a prompt ruling in their behalf.
ID: nht76-5.47 Open DATE: 11/10/76 FROM: AUTHOR UNAVAILABLE; R. L. Carter; NHTSA TO: Department of California Highway Patrol TITLE: FMVSS INTERPRETATION TEXT: Thank you for your August 12 and September 28, 1976, letters to our Office of Standards Enforcement concerning possible noncompliance of certain air-braked school buses with Standard No. 121, Air Brake Systems. At issue is the functioning of a "double check valve" between the two tanks of an air brake system designed to meet S5.7.2 of the standard (as it was in effect prior to September 1, 1976). The valve serves to provide air pressure from either supply reservior to hold off the spring brakes while guarding the air brake system from air loss through either one of the reservoirs. The identified problem stems from construction or installation of the valve such that it does not necessarily operate to seal off the brake system from a loss of air in one of the tanks, permitting loss of air from both reservoirs unless the rate of air loss is substantial. Your letter advises that the State of California is permitting the continued operation of the school buses in question pending receipt of a response from the National Highway Traffic Safety Administration (NHTSA). I would like to address the findings you raise in the order in which they are listed on page two of your letter. I interpret your first finding to be that the "split system" designs used in compliance with Standard No. 121 may be incapable of meeting the stopping distance requirements set forth in S5.7.2. You question whether S5.7.2 adequately specifies a "back up" braking capability that is not cancelled out by a single failure of air pressure components, citing cases where a substantial rate of loss from one tank (introduced as a failure in accordance with S5.7.2.3) draws down the air pressure in both halves of a split system. The general requirement of S5.7.2.3 (of the now superseded text) is that the vehicle, in one out of six attempts under specified conditions, must be capable of stopping from 60 mph within a distance of 613 feet "with a single failure in the service brake system of a part designed to contain compressed air or brake fluid. . . ." To provide this performance (and meet the other requirements of S5.7.2) manufacturers have provided "split systems" modulated by the service brake control. As a matter of general compliance with this requirement, you have asked if any single failure (other than failure of common components) can be introduced into the system as a test of its compliance. The answer to your question is yes. The NHTSA does not know the basis of Ford Motor Company's contention that the "failure" introduced in the system must be at least 50 psi/min from an initial reservoir pressure of 120 psi. A noncompliance with S5.7.2.3 occurs only if the vehicle, with the failure introduced, is incapable of stopping within the prescribed distance in one out of six attempts. Thus, an extremely small failure which is easily overcome by compressor pressure would be one way of testing for compliance with S5.7.2.3, but it would not, in all likelihood, result in the demonstration of a noncompliance. As you noted in the second paragraph of page 3 of your letter, a noncompliance with stopping distance requirements may depend (largely because of a compressor's ability to overcome air loss) on the rate of leakage introduced and the time allowed between introduction of the failure and application of the emergency brake. The standard does not (except for the provision of S6.1.14 for towing vehicles manufactured on or after September 1, 1976) provide detailed specification of procedures, particularly the time between failure and brake application. The agency therefore must utilize a reasonable procedure that does not unfairly test the system. In this case, the agency considers the introduction of any size leak, followed by brake application as soon as the low pressure warning activates, to be a reasonable procedure, approximating what would occur in the event of actual failure on the highway. The agency would find a noncompliance with S5.7.2.3 if the school buses are incapable of stopping within the required distance when the described procedure is followed. Your second finding is that a particular double check valve installation can cause noncompliance with S5.7.2.3. Consistent with our general discussion of compliance with S5.7.2.3, stopping tests are the means to discover whether the buses in question comply. We are analyzing your data, and a noncompliance investigation has been opened. We have notified Ford Motor Company of its commencement. We have also forwarded data to our Office of Defects Investigation to see if the check valve problem constitutes a safety-related defect apart from the issue of compliance. Your last three findings address the separate question of whether the concept of a split system is adequately interfaced with the parking brake requirements of Standard No. 121. First you make the general point that, if S5.7.2.3 permits a substantial loss of air from both sides of a split system, the benefit of redundant lines is negated and the split system requirement is unjustified. The agency understands your position and believes that a stricter control on the amount of permissible leakage (perhaps by means of a limitation on compressor replenishment or a longer period before emergency brake application) may be justified. Particularly important is your point that a compressor loses capability as it grows older, and that this is not accounted for in new-vehicle tests. At the same time, however, larger failures do occur and we continue to view the split system as extremely important for these cases. The split system provides extremely good protection against failures such as rupture of a line or brake chamber diaphragm. With regard to your point that split systems do not guard against failure of components common to the two systems as they are presently constructed (such as the compressor drive belt), I must agree with your point that no brake system can guard against every conceivable failure completely. It is for these cases, in fact, that the agency considers the automatic application of the parking brake system beneficial following loss of the other two capabilities. You make the further point that, in cases of marginal compliance (i.e., the compressor can replace most but not all air loss from both sides of the split system), the gradual loss of system pressure permits parking brake application that interferes with modulation of the emergency capability. While S5.7.2 was designated as "Modulated emergency braking system", no specification for modulation was set forth in its requirements. The agency intended that a system conforming to S5.7.2 would be controlled by the driver instead of by automatic application. Our review of the systems you tested indicates that they are "modulated systems" as contemplated by the agency. The present emergency brake requirements only state that the system "be applied and released, and be capable of modulation, by means of the service brake control." While further specification of this requirement may be in order, I believe it is the early application of the parking brake that actually concerns you, as it affects the application and release of the emergency braking capability. You make the observation that early application of the spring brakes in response to air pressure loss permits them to drag, become overheated, and fade, making them useless before they can be utilized. A related issue is that the spring brakes will apply shortly after emergency brake availability (even before activation of the low air pressure warning), immobilizing the vehicle with no capability to release the parking brakes. You suggest implementation of a parking brake arrangement that would keep the spring brakes off longer or provide an isolated source of air pressure to permit their release when they do lock up. Analysis of your test reports leads me to agree that some specification to limit the early application of spring brakes would be in order. Of course, as you are well aware, notice to interested persons of any change in the standard is required, along with an opportunity for comment. I believe that such rulemaking could be joined with the earlier rulemaking undertaken in response to a California Highway Patrol (CHP) petition (Docket 75-16, Notice 04). Your final point is that, as long as early application of the parking brake is permissible, an isolated tank of air should be available to permit release of the parking brake from the driver's position. With regard to an isolated tank, the NHTSA continues to maintain its view set forth in our November 29, 1974, letter to Donald Gibson of the CHP that the second side of the split system provides more capability than the old systems (with an isolated tank) to avoid a lockup following a service brake failure. However, you have clearly demonstrated that the capability can be essentially negated by early application of the parking brake. I believe that limitations on early application of the parking brake would be a superior correction to the problem than the addition of more components (and complexity) to the existing systems. Because school buses are involved in the problems you cite, you are no doubt aware that @ 103(d) of the National Traffic and Motor Vehicle Safety Act, while preemptive of State regulations or laws of general applicability that are not identical to Federal standards on the same aspect of performance, does not prevent a State or political subdivision from specifying a higher level of brake performance in vehicles "procured for its own use." Thus, the State of California may wish to order school buses with the additional isolated reservoir that you have recommended. The addition of a third tank to a system that complies with the standard's requirements would not be prevented by @ 103(d). I appreciate the constructive approach being pursued by the State of California in enforcement of Standard No. 121. Our Office of Standards Enforcement will keep you advised of the results of its investigation. Sincerely, ATTACH. DEPARTMENT OF CALIFORNIA HIGHWAY PATROL September 28, 1976 File No.: 1.A218.A3107 Francis Armstrong -- Office of Standards Enforcement, National Highway Traffic Safety Administration Dear Mr. Armstrong: In this Department's letter of August 12, 1976, we brought to your attention a problem with the air brakes on school buses built on Ford chassis. We since have allowed the buses to temporarily continue in operation pending a decision by your agency as to their compliance with FMVSS No. 121. At a meeting on September 2, in Sacramento with engineers from Ford Motor Company and Bendix-Westinghouse, this Department took the position that the Ford system did not operate as required by FMVSS No. 121 and did not protect the brakes against a single failure. Ford contended that the system was safe and complied with FMVSS No. 121. They further were of the opinion that a leak in a hose, fitting, or diaphragm of less than 50 psi/min from an initial reservoir pressure of 120 psi was not a "failure" as contemplated in FMVSS No. 121 and, in any event, could be overcome by the continuous operation of the air compressor. The matter was pursued in considerable detail with no meeting of minds. It was found that the vehicle manufacturers' conclusions were based solely on laboratory and static tests and that no failures involving a continuous leak had been simulated on a moving vehicle. They were of the opinion that the usual vibration of the moving vehicle might result in the check valve responding more rapidly in normal service than in static tests. Although we believed the buses did not comply with FMVSS No. 121, we did not desire to keep them out of service if it could be reasonably avoided. On the other hand, we did not wish to allow them to operate if they were imminently unsafe, even if they complied with FMVSS No. 121. We immediately scheduled dynamic tests for the following day to obtain some of the answers. Our investigation showed that the system did not function any better in tests of the moving vehicle than in stationary tests. The same situation was found to exist on other makes of school buses using similar designs. In our opinion, the systems on these buses do not comply with FMVSS No. 121 or are otherwise deficient for the following reasons: 1. It is highly doubtful that the vehicles can meet the emergency stopping distance in FMVSS No. 121 with a single failure in the air system. 2. Some double check valves are so mounted that they shuttle rapidly in one direction and are essentially inoperative in the other direction. 3. The emergency system is not capable of modulation by the service brake control as required by FMVSS No. 121 when loss of air in the service brake reservoirs results in the spring brakes beginning to apply. 4. If the driver does not react rapidly to a low pressure indication, the spring brakes can drag and overheat so as to be ineffective when they are eventually fully applied. 5. Upon failure of a compressor belt, as in the Martinez accident, the depletion of air in the service brake system upon a few brake applications could cause the spring brakes to lock with the vehicle in a hazardous location such as in a tunnel or on railroad tracks. The results of our tests on Ford, International and Gillig buses are shown in the enclosed report. We found that all of the buses had insensitive double check valves between the primary and secondary split system. Although the buses were released for operation by the school district, we still have serious concern that this type of system does little good as an emergency brake system. We ask that you give immediate consideration to a recall investigation to determine if air brakes using the double check valve piping system comply with FMVSS No. 121 and have an effectively-operating emergency stopping system. Our request is based on the following observations during our dynamic tests: 1. The double check valves are not sensitive enough to protect one-half of the dual system against either a mild or substantial air leak in the other half. A leak through a broken hose at a brake chamber with either partial or full foot-brake application did not cause the check valve to shuttle. If the vehicle was going downgrade with the brakes applied, the air would leak out of both systems down to the pressure at which the compressor could keep up with the leak. This ineffective dual system is a waste to the bus or truck operator, as he is no better off than with a single system with no double check valve. 2. It appears questionable whether the vehicles will meet the 60 mph, 613-foot stopping test of Section 5.7.1 of FMVSS No. 121 with a leak equal to the maximum before shuttle movement when the reservoir pressure is stabilized at the compressor output volume. If the vehicles in fact meet this performance requirement under these conditions, the "dual" components are a nonfunctional appendage. With this size leak, the pressure in the "protected" system will eventually be no higher than that in the failed system. Passage of the stopping distance test apparently depends entirely on how quickly the brake pedal is applied after the failure is initiated. 3. Double check valves are installed at the factory in mounting positions that interfere with their operation and any effectiveness that they might have. Some valves were installed with the shuttle axis vertical so that a leak needed to shut off air flow to one reservoir is far less than that at which air flow is shut off to the other reservoir. One ball-check valve was mounted at about a 45-degree angle so the ball immediately shut off a very small leak on the down-hill side but would not shut off the maximum leak that we could reproduce on the uphill side. As a vehicle gets older, contaminates and corrosion products in the system could cause the normally inactive double check valve to hang up when most needed. Even in our tests on a comparatively new vehicle, one of the check valves did not operate nearly as well upon the first simulated leak as on subsequent ones. 4. When a leak occurs, both systems drain down to the point where the spring brakes begin to drag just before the low air pressure indicator comes on. If the driver does not react to the signal, the spring brakes drag more and more as the pressure slowly drops, thereby overheating the linings and drums and destroying the effectiveness of the brakes when they finally are completely on. 5. The driver cannot modulate the brakes with a moderate leak in a supply line in either side of the dual system. The air pressure drops to the point where the spring brakes come on, even with no brake application by the driver. He can then apply the brakes harder by the foot valve, but he cannot release them below the force applied by the spring brakes. The FMVSS No. 121 amendments that became effective September 1, 1976, removed all reference to automatic emergency stopping systems which, if used, were previously required to be releasable by the driver after at least one full application. This feature apparently was intended to be taken care of in the current standard by the modulation requirement. In the systems we tested, the spring brakes could automatically apply with no action by the driver and then could not be released by the modulated treadle valve. We realize that no system can protect against every conceivable possibility and that compromises are necessary because economical protection against one problem may result in an unavoidable creation of a smaller problem. A brake standard cannot meet every need of users and manufacturers under every possible situation, but the standard should be precise enough so users can follow its requirements and are aware of the limited assumptions on which it is based. To this end, we offer the following items that came to light in our tests. If during your investigation, you also find them to be a problem, you might wish to propose solutions to the Office of Crash Avoidance for consideration during the next revision of FMVSS No. 121. 1. Ford Motor Company contended that a leak through a damaged line, hose, diaphragm, etc., was not a "failure" as intended in FMVSS No. 121 unless the line or hose completely severed to produce a pressure drop of at least 50 psi/min from an initial reservoir pressure of 110 psi. We believe a much smaller initial leak of, say, 6 to 10 psi/min should be considered a failure for which the emergency system must compensate. With these differences of opinion, it is essential that the size of leak that constitutes a failure be specifically defined by NHTSA. 2. The stopping distance test conditions of the emergency system should be spelled out in more detail in FMVSS No. 121. The systems we checked would not isolate the protected half of the dual system under the more common failures of hoses and diaphragms. Also, the functioning of the double check valves was dependent upon their mounting position. A manufacturer's test that might be conducted to show compliance with the stopping distance standard with one system completely vented and the other with full air pressure (as would be assumed if the check valve was sensitive) is not realistic. 3. Ford Motor Company contends that their dual system is modulated as required by the standard. We contend that the system is not modulated, or only partially so, when an air leak developes which stabilizes the pressure at less than the 68-psi spring brake initial pressure. The regulation should spell out test conditions sufficient to control the intended degree of modulation. 4. The Ford system depends on compressor output to limit the extent of pressure drop in the system and, consequently, the amount of uncontrolled spring brake application. A new compressor with a 12 cfm rating can, when in good condition, keep up with a considerable air leak, but the emergency stopping system should not be dependent upon this factor. Some compressors are almost too small for some systems and many lose much of their capacity after they are in service over a period of time. The deficiencies in the present split-air system would not be so important if a protected air tank was added to allow the spring brakes to release after the automatic application that occurs when one leak causes the air to be drained from both systems. The driver would then be able to release the spring brakes to remove the vehicle from a potentially hazardous location. Other modifications might be desirable such as the use of pressure protection valves shown in the enclosed Bendix-Westinghouse school bus system which was developed in accordance with California law a few years back. I am sure you are aware of the intense national interest in school bus defects since the Martinez charter bus accident in which 29 persons were killed. The news media is sensitive to matters of school bus operation and may request information concerning our evaluation and recommendations to your agency. The possibility of such inquiry provides additional reason for your expeditious review and resolution of this matter. I urge you to take immediate steps to require air brake systems of the types described in the enclosed report to be redesigned to comply with FMVSS No. 121 and to effectively protect the vehicles against brake failure. Very truly yours, G. B. CRAIG -- Commissioner Enclosures DEPARTMENT OF THE CALIFORNIA HIGHWAY PATROL INSPECTION OF DUAL AIR BRAKE SYSTEMS ON SCHOOL BUSES ENFORCEMENT SERVICES DIVISION SEPTEMBER 1976 TABLE OF CONTENTS Page ABSTRACT 1 BACKGROUND 1 PROCEDURE 4 TEST RESULTS 4 I. Tests of 1976 Bluebird School Bus on a Ford Chassis 4 II. Tests of 1976 Superior School Bus on a Ford Chassis 6 III. Tests of 1975 Ward School Bus on an International Chassis 8 IV. Tests of 1976 Gillig School Bus 10 DISCUSSION 11 CONCLUSION 14 [REPORT OMITTED]
ID: nht78-2.3 Open DATE: 12/13/78 FROM: AUTHOR UNAVAILABLE; J. J. Levin, Jr.; NHTSA TO: Mack Trucks, Inc. TITLE: FMVSS INTERPRETATION TEXT: December 13, 1978 NOA-30 Mr. T. F. Brown Mack Trucks, Inc. Engineering Division P.O. Box 1761 Allentown, Pennsylvania 18105 Dear Mr. Brown: I regret the delay in responding to your August 31, 1978, letter requesting an interpretation of S5.3 of Federal Motor Vehicle Safety Standard No. 120. In that letter, you stated that you had been contacted by an employee of this agency's enforcement office and advised that the certification labels for Mack trucks did not comply with the requirements of that section. The reason given for this conclusion was that the labels used the word "on" between the tire and rim information instead of the comma shown in the example following S5.3.3. S5.3 requires that the labeling information specified in S5.3.1 -S5.3.3 must appear in the format shown in the truck example following S5.3.3. This requirement does not mean that certification labels must be identical to the example in every respect. Minor variations are permitted. By "minor variations", I mean such things as a slight difference in punctuation or the substitution of a word for a punctuation mark that do not change or obscure the meaning of the label. Mack's substitution of "on" for a comma is such a minor variation and, accordingly, is permissible under the standard. The label enclosed with your letter shows spaces to provide information for the front, rear and three intermediate axles. When this label is used on vehicles with fewer than five axles, you should stamp "Not applicable", or words of similar import, in the spaces provided for axles which do not exist on the particular vehicle which is being labelled. Without this indication, the label could be confusing and so would fail to clearly provide the required information for that vehicle. An indication of nonapplicability would alert the reader to that fact. Sincerely, Joseph J. Levin, Jr. Chief Counsel August 31, 1978 Administrator, National Highway Traffic Safety Administration U.S. Department of Transportation 400 Seventh Street, S.W. Washington, D.C. 20590 Dear Sir: SUBJECT: Request for Interpretation GAWR-Tire-Rim Labeling Requirements FMVSS 120 - Vehicle Certification Labels Mack Trucks, Inc, a manufacturer of heavy duty diesel trucks of 26,000 pounds GVWR and greater, is requesting an interpretation of the specific GAWR-tire-rim labeling requirements of FMVSS 120, Tire Selection and Rims for Motor Vehicles Other Than Passenger Cars. We were advised, by telephone, by a member of the NHTSA's Office of Vehicle Safety Compliance staff that there were several minor discrepancies found on one of our vehicle certification labels. Four items were noted as being incorrect. Three of these four items were well-taken, and steps to avoid a reoccurrence of these errors have been taken. The fourth item, however, is the reason for this letter. Our certification labels set up the gross axle weight ratings, tire, and rim information as follows: FRONT AXLE WITH TIRES ON RIMS AT COLD SINGLE We were advised that we could not use the word "ON" as shown above, but should instead use a comma as is illustrated in the "Truck example" shown following Paragraph S5.3.3 of FMVSS 120. Paragraph S5.3 oF FMVSS 120 states that the information shall appear in the "format" set forth in the example following Section S5.3. It is our contention that the GAWR and associated information on our certification labels, including the word "ON", does comply with the format set forth following Section S5.3 of FMVSS 120. The word "ON" actually makes the meaning of the statement clearer. If you look closely at the attached sheet showing one of our labels and the "Truck example" from FMVSS 120, you will note that they are not exactly identical. Therefore, we wonder why only our use of the word "ON" was singled out. (NOTE: The other three items noted in the telephone conversation dealt with information that had been added to the certification label on the vehicle inspected by NHTSA.) We believe we are presenting all the required information in a form substantially identical to that illustrated in the "Truck example", and that we are in compliance with the applicable regulations. Therefore, we are requesting an interpretation of the specific GAWR-tire-rim labeling requirements of FMVSS 120. If further discussion of this subject is necessary, please contact the writer at 215-439-3877. Very truly yours, MACK TRUCKS, INC, T. F. Brown Executive Engineer- Vehicle Regulations and Standards vy Attach. Insert attachment here (FMVSS 120) found in card copy file.

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