ID: 2839yy

The Honorable John D. Dingell
Chairman, Subcommittee on Oversight
and Investigations
Committee on Energy and Commerce
House of Representatives
Washington, DC 20515

Dear Mr. Chairman:

Your letter of July 10, 1990 about the applicability of NHTSA's safety standards to replacement parts was misplaced. This is indeed unfortunate, embarrassing, and I can assure you extraordinary. You asked me to review an April 9, 1990 interpretation letter from our Office of Chief Counsel to Mr. Rowghani, which indicated that Standard No. 214, Side Door Strength, applies only to new vehicles, and not to doors sold as replacement parts.

In view of your concern about replacement parts, we have reviewed that interpretation, and our authority regarding replacement parts. Many of our safety standards apply only to complete vehicles, while others apply only to the individual components (whether original or replacement equipment). Some apply both to vehicles and to the components involved. Each of our standards includes an "Application" section, which clearly defines the scope of coverage, based on the nature of the safety issue and the vehicle/equipment items involved.

NHTSA's standards which apply to equipment (both original and replacement equipment) generally cover those types of items which can be used in many different vehicle lines, which are frequently replaced or sold separately, and which can be independently tested. These include such items as brake hoses (Standard 106), lamps and reflectors (Standard 108), tires (Standards 109, 117 and 119), windows and windshields (Standard 205), safety belt assemblies (Standard 209), child safety seats (Standard 213), and motorcycle safety helmets (Standard 218). Other safety systems require testing in a full-vehicle context, and our safety standards are applied to the vehicle rather than the component. Examples include brake performance (Standards 105 and 121), occupant crash protection (Standard 208), head restraints (Standard 202) and roof-crush resistance (Standard 216), as well as side-door strength.

As noted in the April 9 letter, Standard 214 applies only to whole cars, not to replacement parts, as stated in the application section (see S2 of Standard 214, copy enclosed). While most manufacturers have chosen to meet the Standard by adding reinforcement beams, we are aware of at least one vehicle (a gray-market imported Mercedes-Benz) which passed the standard's compliance test without such a beam. Further, while intuitively it seems that doors without a reinforcement beam are not as safe as ones with a beam, efforts to document a safety problem have been unsuccessful.

The current compliance procedures specify testing a door as part of a new vehicle (see S4 of Standard 214), since it does not appear feasible to specify an appropriate procedure for testing an individual new door (whether original or replacement) by itself. The reason for this is that a door's performance in resisting intrusion is dependent not only on the structure of the door itself, but also other factors such as the vehicle frame into which the door fits, and the hinges and latches which hold the door in place within the frame. In addition, vehicle seats may help resist intrusion and protect occupants. The current standard reflects these factors.

While the current standard does not apply to replacement doors, NHTSA has full authority to pursue any alleged safety problems with doors or any other vehicle components under the "defects" provision of the Safety Act. If evidence demonstrated that certain replacement doors presented an unreasonable risk to motor vehicle safety, the agency could order the manufacturer of such doors to repair or replace such doors. At the present time, however, we are not aware of a safety problem with replacement doors that would warrant the commencement of a defects investigation.

I appreciate your interest in the safety of vehicle parts and hope this information is helpful. For further discussion of the legal issues regarding the applicability of standards, your staff should feel free to contact our Chief Counsel, Mr. Paul Jackson Rice, at 366-9511.

Sincerely,

Jerry Ralph Curry

Enclosure /ref:214 d:2/l5/9l

ID: nht91-1.42

DATE: February 15, 1991

FROM: Jerry Ralph Curry -- NHTSA

TO: John D. Dingell -- Chairman, Subcommittee on Oversight and Investigations, Committee on Energy and Commerce, House of Representatives

TITLE: None

ATTACHMT: Attached to letter dated 7-10-90 from John D. Dingell to Jerry R. Curry; Also attached to letter dated 1-9-90 from Mehdi Rowghani to Taylor Vinson; Also attached to letter dated 4-9-90 from Stephen P. Wood to Mehdi Rowghani

TEXT:

Your letter of July 10, 1990 about the applicability of NHTSA's safety standards to replacement parts was misplaced. This is indeed unfortunate, embarrassing, and I can assure you extraordinary. You asked me to review an April 9, 1990 interpretation letter from our Office of Chief Counsel to Mr. Rowghani, which indicated that Standard No. 214, Side Door Strength, applies only to new vehicles, and not to doors sold as replacement parts.

In view of your concern about replacement parts, we have reviewed that interpretation, and our authority regarding replacement parts. Many of our safety standards apply only to complete vehicles, while others apply only to the individual components (whether original or replacement equipment). Some apply both to vehicles and to the components involved. Each of our standards includes an "Application" section, which clearly defines the scope of coverage, based on the nature of the safety issue and the vehicle/equipment items involved.

NHTSA's standards which apply to equipment (both original and replacement equipment) generally cover those types of items which can be used in many different vehicle lines, which are frequently replaced or sold separately, and which can be independently tested. These include such items as brake hoses (Standard 106), lamps and reflectors (Standard 108), tires (Standards 109, 117 and 119), windows and windshields (Standard 205), safety belt assemblies (Standard 209), child safety seats (Standard 213), and motorcycle safety helmets (Standard 218). Other safety systems require testing in a full-vehicle context, and our safety standards are applied to the vehicle rather than the component. Examples include brake performance (Standards 105 and 121), occupant crash protection (Standard 208), head restraints (Standard 202) and roof-crush resistance (Standard 216), as well as side-door strength.

As noted in the April 9 letter, Standard 214 applies only to whole cars, not to replacement parts, as stated in the application section (see S2 of Standard 214, copy enclosed). While most manufacturers have chosen to meet the Standard by adding reinforcement beams, we are aware of at least one vehicle (a gray-market imported Mercedes-Benz) which passed the standard's compliance test without such a beam. Further, while intuitively it seems that doors without a reinforcement beam are not as safe as ones with a beam, efforts to document a safety problem have been unsuccessful.

The current compliance procedures specify testing a door as part of a new vehicle (see S4 of Standard 214), since it does not appear feasible to specify an appropriate procedure for testing an individual new door (whether original or replacement) by itself. The reason for this is that a door's performance in resisting intrusion is dependent not only on the structure of the door itself, but also other factors such as the vehicle frame into which the door fits, and the hinges and latches which hold the door in place within the frame. In addition, vehicle seats may help resist intrusion and protect occupants. The current standard reflects these factors.

While the current standard does not apply to replacement doors, NHTSA has full authority to pursue any alleged safety problems with doors or any other vehicle components under the "defects" provision of the Safety Act. If evidence demonstrated that certain replacement doors presented an unreasonable risk to motor vehicle safety, the agency could order the manufacturer of such doors to repair or replace such doors. At the present time, however, we are not aware of a safety problem with replacement doors that would warrant the commencement of a defects investigation.

I appreciate your interest in the safety of vehicle parts and hope this information is helpful. For further discussion of the legal issues regarding the applicability of standards, your staff should feel free to contact our Chief Counsel, Mr. Paul Jackson Rice, at 366-9511.

ID: aiam4962

"Dear Mr. Harris: This responds to your letter asking about Federa motor vehicle safety standards applicable to your product, which you described as a cloth device containing plastic items useful to a baby, for use in motor vehicles. You explained that your product would be placed in a motor vehicle adjacent to, but not touching, a child in a nearby child safety seat. In particular, you were concerned about flammability resistance standards applicable to your product. I am pleased to have this opportunity to explain our requirements to you. I am also enclosing a copy of a fact sheet entitled 'Information for New Manufacturers of Motor Vehicles and Motor Vehicle Equipment.' By way of background information, NHTSA is authorized to issue Federal Motor Vehicle Safety Standards that set performance requirements for new motor vehicles and items of motor vehicle equipment. Section 102(4) of the Safety Act defines, in relevant part, the term 'motor vehicle equipment' as: any system, part, or component of a motor vehicle as originally manufactured or any similar part or component manufactured or sold for replacement or improvement of such system, part, or component or as any accessory, or addition to the motor vehicle ... In determining whether an item of equipment is considered an accessory, NHTSA applies two criteria. The first criterion is whether a substantial portion of the expected use of the item is related to the operation or maintenance of motor vehicles. We determine the expected use by considering product advertising, product labeling, and the type of store that retails the product, as well as available information about the actual use of the product. The second criterion is whether the product is intended to be used principally by ordinary users of motor vehicles. If the product satisfies both criteria, then the product is considered to be an 'accessory' and thus is subject to the provisions of the Safety Act. Applying these criteria to the cloth device containing baby items, it appears that your product would be an accessory and thus an item of motor vehicle equipment under the Safety Act. Based on our understanding of your device, it appears that a substantial portion of its expected use will be during the operation of a motor vehicle. In a telephone conversation with Ms. Dee Fujita of my staff, you explained that your device is intended to be sold for use in motor vehicles. In addition, it appears that your product would typically be used by ordinary users of motor vehicles. While it appears that your device would be considered an item of motor vehicle equipment, this agency has not issued any standards setting forth performance requirements for such a device. Obviously, your device could not be determined to be in noncompliance with a safety standard if there is no applicable safety standard. As for your concern about flammability resistance requirements, please be advised that our safety standard about this issue, Standard No. 302, Flammability of Interior Materials, (49 CFR 571.302, copy enclosed), would not apply to your device. That standard sets forth such requirements applicable to new motor vehicles and not to motor vehicle equipment. You should be aware that, as a manufacturer of an aftermarket item of motor vehicle equipment, you are subject to the requirements in sections 151-159 of the Safety Act concerning the recall and remedy of products with defects related to motor vehicle safety. In the event that you or NHTSA determines that your product contains a safety related defect, you would be responsible for notifying purchasers of the defective equipment and for remedying the problem free of charge. I hope this information is helpful. If you have any further questions about NHTSA's safety standards, please feel free to contact Marvin Shaw of my staff at this address or by telephone at (202) 366-2992. Sincerely, Paul Jackson Rice Chief Counsel Enclosure";

ID: aiam4765

"Dear Mr. Brush: Thank you for your letter to Mr. Clive Van Orden o our Office of Vehicle Safety Compliance seeking an interpretation of this agency's requirements for a vehicle identification number (VIN), as set forth in 49 CFR Part 565, Vehicle Identification Number - Content Requirements, and Standard No. 115, Vehicle Identification Number - Basic Requirements (49 CFR 571.115). You stated that your company plans to modify vans manufactured by General Motors (GM) to produce electric powered vehicles for sale in the United States. You asked whether these vehicles may use the GM world manufacturer identifier (WMI), as well as a check digit, model year identification, and production sequence codes assigned by GM, and use an X as the engine type code to show that the vehicles were actually manufactured by your company. As explained below, the answer to your question is no. S4.1 of Standard No. 115 reads as follows: Each vehicle manufactured in one stage shall have a VIN that is assigned by the manufacturer. Each vehicle manufactured in more than one stage shall have a VIN assigned by the incomplete vehicle manufacturer. Vehicle alterers, as specified in 49 CFR 567.7, shall utilize the VIN assigned by the original manufacturer of the vehicle. As described in your letter, Conceptor Industries plans to produce completed electric powered vehicles by using an assemblage of motor vehicle equipment produced by GM, including frame and chassis structure, steering, suspension, and braking systems. However, the assemblage provided to your company by GM would not include a power train. The absence of a power train means that this assemblage would not be an 'incomplete vehicle,' as that term is defined in S3 of Standard No. 115, so the Conceptor electric vehicles would not be considered to be manufactured in more than one stage. Your company would not qualify as a vehicle alterer, based on the information provided in your letter, because GM would not have already certified the vehicles modified by your company. Thus, the electric powered vehicles produced by Conceptor would be considered to be vehicles manufactured in one stage, and the VIN for these vehicles would have to be assigned by Conceptor, the manufacturer of these vehicles. Part 565 specifies the format and content of the VIN that Standard No. 115 requires your company to assign to its electric powered vehicles. In relevant part, 49 CFR 565.4 provides that: The VIN shall consist of four sections of characters which shall be grouped accordingly: (a) The first section shall consist of three characters which occupy positions one through three (1-3) in the VIN, This section shall uniquely identify the manufacturer, make and type of the motor vehicle if its manufacturer produces 500 or more motor vehicles of its type annually. If the manufacturer produces less than 500 motor vehicles of its type annually, those three characters, along with the third, fourth, and fifth characters of the fourth section shall uniquely identify the manufacturer, make and type of the motor vehicle. * * * Under the approach suggested in your letter, GM would be identified as the manufacturer of the vehicle by the first three characters of the VIN, and the eighth character would indicate that Conceptor was the actual manufacturer. This approach would be plainly inconsistent with the requirements of 565.4 quoted above, because the regulation requires the first three characters in the VIN to identify the vehicle manufacturer. Your company is the manufacturer of these vehicles, not GM, so your company must be identified by the first three characters of the VIN. Furthermore, 565.4(b) provides that the eighth character in the VIN shall uniquely identify specified attributes of the vehicle, not identify the manufacturer. Hence, the approach suggested in your letter would not comply with this agency's VIN requirements. Additionally, you informed Dorothy Nakama of my staff in a July 3, 1990 telelphone conversation that, at least in the initial years of your company's production of these vehicles, the annual production will be less than 500. If this is the case, you should note that 565.4(a) requires your company to use not only the first three characters of the VIN to uniquely identify the manufacturer, make and type of the motor vehicle, but also the 12th, 13th, and 14th characters of the VIN as well to make this unique identification. I hope this information is helpful. If you have any further questions or need any additional information, please feel free to contact Dorothy Nakama of my staff at this address or by telephone at (202) 366-2992. Sincerely, Paul Jackson Rice Chief Counsel";

ID: nht89-2.87

TYPE: INTERPRETATION-NHTSA

DATE: 08/30/89

FROM: STEPHEN P. WOOD -- NHTSA ACTING CHIEF COUNSEL

TO: E. H. GALLOWAY -- UNIFORM TIRE QUALITY GRADING TEST FACILITY

TITLE: INFLATION PRESSURES FOR TRACTION GRADING PROCEDURES IN UTQGS

ATTACHMT: ATTACHED TO LETTER DATED 11/01/89 FROM STEPHEN P. WOOD -- NHTSA TO FRANK E. TIMMONS -- RUBBER MANUFACTURERS ASSOCIATION, REDBOOK A34, STANDARD 109, PART 575.104; LETTER DATED 09/28/89 FROM FRANK E. TIMMONS -- RUBBER MANUFACTURERS ASSOCIATION TO STEPHEN P. WOOD -- NHTSA, OCC 3994.

TEXT: In telephone conversations with Steve Kratzke and Marvin Shaw of my staff on August 10, 1989, you requested written confirmation of your interpretation of a requirement set forth in the traction grading procedures of the Uniform Tire Quality Grading Stan dards (UTQGS; 49 CFR @ 575.104). Specifically, you noted that @ 575.104(f)(2)(i)(B) specifies that one "inflate the tire to 24 psi, or, in the case of a tire with inflation pressure measured in kilopascals, to 180 kPa." There is a similar provision for readjusting the inflation pressure of tires during traction testing in @ 575.104(f)(2)(i)(D).

You stated that these provisions are clear as to the appropriate inflation pressure to be used during the testing of tires whose inflation pressure is expressed solely in English units (as pounds per square inch or "psi") or solely in metric units (as ki lopascals or "kPa"). However, you suggested that there is some uncertainty about the appropriate inflation pressure to be used with tires whose inflation pressure is expressed in both English units and the equivalent metric units, an increasingly common practice. You stated that you have been inflating tires whose inflation pressure is expressed in both English and metric units to 24 psi during testing for traction grading, and asked that we confirm that this is the proper inflation pressure for these tires. Your interpretation is correct.

The language of the regulation sets forth a general requirement for an inflation pressure of 24 psi, and a subordinate requirement that tires "with inflation pressure measured in kilopascals" use an inflation pressure of 180 kPa. An examination of the b ackground of this language shows that the alternative inflation pressure of 180 kPa is to be used only for tire sizes that have inflation pressures specified only in kilopascals.

As you know, the UTQGS were originally promulgated with a requirement that all tires use an inflation pressure of 24 psi during the traction testing. This created some problems for tires whose inflation pressure was expressed solely in metric units. In a February 7, 1979 letter to Mr. Leon Conner, the agency stated:

In the situation where no cold inflation pressure exactly equivalent to the specified pressure of 24 psi is stated in [the tire tables] for a tire size designation, the tires to be tested are inflated to the pressure listed for the tire size designati on in [the tire tables] which is nearest to 24 psi, i.e., 180 kPa for tires with inflation pressures measured in kilopascals. The agency plans to issue an interpretive amendment to the regulation clarifying this point.

As indicated in the letter to Mr. Conner, the agency proposed to amend the UTQGS in a notice published October 1, 1979 (44 FR 56389). The preamble to that notice described the proposal as being addressed to tires that do not have any inflation pressure corresponding precisely to 24 psi, and proposing to amend the regulation to provide that those tires should use an inflation pressure of 180 kPa. The final rule adopting this change stated that it was adopting the inflation pressure proposed in the NPRM . See 45 FR 70273, October 23, 1980. This background indicates that the agency intended tires to be inflated to 180 kPa during traction testing only if no information was shown for that tire size under a column for an inflation pressure of 24 psi in the tire tables formerly incorporated in Standard No. 109. The only tire sizes for which information was not shown in a 24 psi column were tire sizes whose inflation pressure was expressed exclusively in metric units. Hence, any tires whose inflation press ure is expressed in both English and metric units should be inflated to 24 psi during the UTQGS traction testing.

Our second comment concerns the fact that in the turn signal mode the unused turn signal lamp would continue to be illuminated when the brake pedal is applied. Thus, an observer would see a flashing turn signal and a steady burning one, whereas with an ordinary vehicle, the observer would see only the flashing turn signal. Whether the presence of the steady burning turn signal on the side of the vehicle opposite the flashing turn signal would detract from the effectiveness of the flashing turn signal, and by obscuring its message make it "partially inoperative", is difficult to judge. Certainly, when a vehicle is signaling a turn, it does not appear necessary to also indicate, to the front, that it is stopping.

These remarks also serve as some comments of this Office as to "safety benefits" that might result from vehicles equipped with your device. Certainly, no standard lighting equipment on vehicles today indicate from the front that the brake pedal is being applied. This is an interesting concept, and we appreciate your interest in enhancing motor vehicle safety.

Sincerely,

ID: aiam3018

Dear Mr. Kelly: This is in response to your letter of January 12, 1979, requesting a interpretation of the term 'production process' as used in 49 CFR 571.115, S4.5.3.3. We are sorry for the delay in responding.; The production practice you describe on page 2 of your letter woul satisfy S4.5.3.3. In the preamble to the final rule published on August 17, 1978 (43 FR 36451), the agency stated:; >>>The NPRM proposed that the last six characters represent th sequential number of a vehicle when the manufacturer produced more than 500 vehicles annually of that type.; A number of comments pointed out that for various reasons a vehicl might be taken from a production line, thereby having an actual sequential number which differs from the production sequence number originally assigned by the manufacturer. The proposal is amended to indicate that the production sequence number is required.<<<; Thus, Pullman Trailmobile should indicate the sequential numbe originally assigned by the manufacturer, not the number reflecting exact order in which the vehicle is produced.; Sincerely, Frank Berndt, Chief Counsel

ID: 11705-1.PJA

Mr. James O. Webb
Chief Engineer
Converto Mfg. Co., Inc.
P.O. Box 287
Cambridge City, Indiana 47327

Dear Mr. Webb:

This responds to your letter pointing out some difficulties you anticipate in complying with the National Highway Traffic Safety Administration=s (NHTSA) recent rear impact protection (underride guard) regulations. Your company manufactures Aroll off@ hoist equipment, both trailer and truck mounted, that is used to pick up, put down, and dump the long rectangular dumpsters often used to collect trash and construction debris. The short answer to your question is that your straight-body vehicles are excluded from the requirements, while the trailers are not.

Your equipment basically consists of frame rails that lay on the back of the truck or trailer and are hinged at the rear of the trailer. To load a dumpster, the front end of the frame rails are raised by hydraulic pistons to a 45 to 50 degree angle, until the rear end of the rails touches the ground behind the vehicle. Once at this angle, a hoist cable pulls the dumpster up the rails onto the back of the vehicle, after which the pistons are collapsed to return the dumpster to a horizontal orientation. The opposite sequence is used to lower the dumpster. Based on the product literature you enclosed, it appears that your factory mounts this equipment on new truck and trailer chassis prior to first sale. You state that it would be impractical, if not impossible, to mount underride guards on these vehicles, presumably because the guard would be mounted on the rails and would prevent them from being fully raised.

Federal Motor Vehicle Safety Standard (FMVSS) No. 224, Rear impact protection, requires most trailers and semitrailers weighing over 10,000 pounds to be fitted at the rear with a rear impact (underride) guard meeting the requirements of FMVSS No. 223, Rear impact guards (49 CFR 571.223 and 571.224, published on January 24, 1996 at 61 FR 2004). Two excluded categories of vehicles that are relevant for the purposes of this letter are single unit trucks and special purpose vehicles.

With regard to the Outside Rail Roll-off Tilt Frame Hoist installed on a truck, the vehicle is excluded. Note that the regulation applies only to trailers and semitrailers. Because these vehicles are single unit (i.e., unarticulated) trucks, FMVSS No. 224 does not apply to them.

A special purpose vehicle is defined in S4 of FMVSS No. 224 as being Aa trailer or semitrailer having work- performing equipment . . . that, while the vehicle is in transit, resides in or moves through the area that could be occupied by the horizontal member of the rear underride guard . . . (emphasis added).@ Your Semi- trailer Roll-off Tilt Frame Hoist is not excluded, because it does not meet the definition of a special purpose vehicle. Although NHTSA considers the rails to be work performing equipment that, as the frame is tilted, passes through the area where the horizontal member of the underride guard would be located, they do not do so while the vehicle is in transit.

NHTSA addressed the issue of roll off hoist trailers in the final rule. The National Solid Wastes Management Association (NSWMA), a trade group that we believe represents many of your customers, requested special consideration for roll-off hoist vehicles. However, NSWMA=s main objection was requiring guards on the containers themselves, which is not your concern. NSWMA stated in their comment that:

[t]he most common type of roll-off tilt frame used is the >outside rail= design . . . In these cases the rear underride [guard] required by [23 CFR] 393.86 will contact the ground at a frame tilt angle of approximate [sic] 40 degrees. Since this causes instability if the ground is uneven, a number of manufacturers have resorted to a retractable underride [guard] design, where a strut attached to the rear chassis frame will cause the underride [guard] to move forward and out of the interference area as the frame is tilted.

NHTSA assumed by this comment that a design solution had been found to address the problem of the guard hitting the ground. Therefore, NHTSA believed it was only necessary to respond to NSWMA that guards were not required on the container, only the trailer that carries it. We suggest that you contact NSWMA to explore the possibility of using the retractable guard design that it discussed.

If you believe your trailers should be excluded from Standard No. 224, you may submit a petition for rulemaking (see 49 CFR Part 552, which I have enclosed for your convenience) requesting that NHTSA amend the standard. If you have any further questions, please feel free to contact Paul Atelsek of my staff at this address or by telephone at (202) 366-2992.

Sincerely,

Samuel J. Dubbin Chief Counsel

1 Enclosure: Part 552 ref:224 d:5/16/96

ID: aiam1789

Dear Mr. Semark: This is in reply to your letter of January 16, 1975, asking whether yo must install clearance lamps on a vehicle's rear fenders, rather than its body, in order to conform to Motor Vehicle Safety Standard No. 108.; Table II of Standard No. 108 requires red clearance lamps to be 'on th rear, to indicate the overall width of the vehicle . . . and as near the top as practicable.' Paragraph S4.3.1.1 requires clearance lamps to be located so as to meet the visibility requirements of SAE Standard J592e, which includes test points at 45 degrees inboard. Therefore, the location of clearance lamps as shown on the TBEA sheet you enclosed conforms to the intent of the standard. Clearance lamps mounted near the top and outer extremities of a body, as in your diagrams, do sufficiently indicate overall width for purposes of safety, even though the actual vehicle width at the fender may be somewhat greater.; Yours truly, Richard B. Dyson, Asst. Chief Counsel

ID: aiam2830

Dear Mr. Caristia: Our regional office in White Plains has forwarded your letter of Ma 29, 1978, for reply.; You have requested 'approval' of your vehicle lighting system whic flashes the stop lamps at a rate three times per second when the brake pedal is depressed.; We do not 'approve' lighting devices but we do provide interpretation whether such devices are permissible under Federal lighting requirements. As an item of original vehicle equipment your device would appear to be prohibited by paragraph S4.6 of Federal Motor Vehicle Safety Standard No. 108. This paragraph requires that all lamps be steady - burning in operation except for turn signal lamps, hazard warning, signal lamps, and school bus warning lamps, and it also allows headlamps and side marker lamps to be flashed for signalling purposes.; As an aftermarket device, however, it would be subject to regulation b the individual States. We are forwarding a copy of your letter to the American Association of Motor Vehicle Administrators for an opinion on this point.; We appreciate your interest in safety. Sincerely, Joseph J. Levin, Jr., Chief Counsel

ID: nht93-4.4

DATE: May 19, 1993

FROM: Richard A. Zander -- Project Engineer, AlliedSignal Automotive Proving Grounds

TO: Office of Chief Council, NHTSA

TITLE: None

ATTACHMT: Attached to letter dated 3/23/94 from John Womack to Richard A. Zander (A42; Std. 105)

TEXT:

I am writing to obtain your official interpretation of the following statement in 49 CFR 57, 105 Section S5.1.4.2(a) "each vehicle with GVWR of 10,000 lbs. or less shall be capable of making 5 fade stops (10 fade stops on the second test) from 60 mph at a deceleration not lower than 15 fpsps for each stop, followed by 5 fade stops at the maximum deceleration attainable from 5 to 15 fpsps."

I am requesting your official interpretation of the phrase "at a deceleration not lower than 15 fpsps for each stop." As further reference Section S7.11.2.1 states "Attain the required deceleration within 1 second and, as a minimum, maintain it for the remainder of the stopping time."

Within the industry, I know of three different interpretations of this statement, there could by more:

1. The average deceleration for the stop must be greater than 15 fpsps. The average deceleration is calculated from one second after the stop begins to a vehicle speed of 5 mph.

2. After 1 second the deceleration can not drop below 15 fpsps even for an instant. If the deceleration drops below 15 fpsps at any time it is considered a failure even if the average deceleration is greater than 15 fpsps. 3. The average deceleration for the stop must be greater than 15 fpsps and the deceleration must be greater than 15 fpsps for at least 75% of the stop excluding the first second of the stop.

In the "Laboratory procedures for FMVSS No. 105-83, TP-105-83-00, dated January 31, 1984, page 1.49, data sheet No. 1.16 for the fade stops, requests the following information for the deceleration "Average Sust Decel" see pages 1 and 2 of Attachment A. Therefore, it appears that NHTSA's interpretation of the statement "at a deceleration not lower than 15 fpsps for each stop" is "the average sustained deceleration."

Pages 3 & 4 of attachment A are a typical fade stops. The X axis is time and on the Y axis is deceleration and pedal force.

Interpretation ONE would consider these a pass because the average deceleration was greater than 15 fpsps and the pedal force did not exceed 150 lbs.

Interpretation TWO would consider these a fail because several data points fell below 15 fpsps. This interpretation appears to not consider the intent of the fade procedure. The intent being that a vehicle be capable of making multiple

high deceleration stops in a short period of time without drastic changes in effectiveness. Thus the recovery stops have a maximum and a minimum pedal force requirement based on the baseline check stops.

Maintaining an average deceleration of at least 15 fpsps insures adequate heat build up in the linings to determine if they will fade or drastically change effectiveness.

The deceleration could fall below 15 fpsps for short periods of time due to instrumentation noise or in stop fade which was not immediately compensated for by the driver. Interpretation THREE would consider these a pass because the average deceleration is greater than 15 fpsps and the deceleration is greater than 15 fpsps for 75% of the stop after the first one second.

Considering the intent of the fade procedure, the 75% requirement is not necessary to insure adequate heat build-up in the linings.

The NHTSA interpretation "average sustained deceleration" would also consider these a pass.

I am also requesting that you send the latest version of the test procedure for FMVSS No. 105 from the office of vehicle compliance. Please send to:

Richard Z. Zander Allied Signal Automotive Proving Grounds 3214 State Road 2 New Carlisle, IN 46552

Thank you for your time and effort to respond to my requests.

ATTACHMENT

Laboratory Procedures for Federal Motor Vehicle Safety Standard No. 105-83; TP-105-83-00; January 31, 1984. (Text omitted)