ID: nht90-1.80

TYPE: INTERPRETATION-NHTSA

DATE: 03/20/90

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

TO: R.M. COOPER -- V.P, ENGINEERING, GILL G CORPORATION

TITLE: NONE

TEXT: This response to your letter asking this agency to consider a problem your company faces with respect to Standard 217, Bus Window Retention and Release (49 CFR @ 571.217). More specifically, you asked how some of your buses could be certified as complyi ng with the emergency exit labeling requirements set forth in Standard 217 for buses other than school buses. I apologize for the delay in this response.

Paragraph S5.5.1 of Standard 217 provides that, in buses other than school buses, each push-out window or other emergency exit shall have the designation "Emergency Exit" followed by concise operating instructions, describing each motion necessary to unl atch and open the exit, located within 6 inches of the release mechanism. The purpose of this requirement is to identify for bus occupants the location and explain the use of specially-installed emergency exits. As I understand your letter, you have no difficulties providing appropriate instructions in the specified location.

Paragraph S5.5.1 continues with the following language:

When a release mechanism is not located within an occupant space of an adjacent seat, a label . . . that indicates the location of the nearest release mechanism shall be placed within the occupant space.

The terms "adjacent seat" and "occupant space" are defined in S4 of Standard 217 as follows:

"Adjacent seat" means a designated seating position located so that some portion of its occupant space is not more than 10 inches from an emergency exit, for a distance of at least 15 inches measured horizontally and parallel to the exit.

"Occupant space" means the space directly above the seat and footwell, bounded vertically by the ceiling and horizontally by the

normally positioned seat back and the nearest obstruction of occupant motion in the direction the seat faces.

You stated that many of your buses have seats that face the aisle and that back up against windows designated as emergency exits. These aisle-facing seats are "adjacent seats" with respect to the emergency exits. The release mechanism for the emergency exit is not within the "occupant space" for these aisle-facing seats, since the release mechanisms are behind, not above, these seats. You enclosed a group of photographs to further illustrate this situation.

Since the release mechanism for the emergency exit is not within the occupant space of these adjacent aisle-facing seats, paragraph S5.5.1 of Standard 217 requires a label indicating the location of the release mechanism for the emergency exit to be plac ed within the occupant space for these seats. You have noted that the occupant space for these seats does not include any place to which this label could be attached. The nearest obstruction of occupant motion in the direction the aisle-facing seats fa ce is the aisle facing seat on the opposite side of the bus. There are no intervening objects other than narrow vertical stanchions in the center of the aisle. Additionally, you suggested that placing the label on the floor or ceiling of the bus would not serve the purposes of this requirement, since those locations would not be readily visible to the seated occupant in an emergency situation.

In response to your letter, we have carefully considered the labeling requirements of S5.5.1 as they apply to aisle-facing seats in front of windows that serve as emergency exits. The final rule adopting this additional labeling requirement explained th at NHTSA was concerned that an occupant of an adjacent seat might hinder egress through an emergency exit if the occupant did not know how to use the emergency exit. See 37 FR 9394, at 9395; May 10, 1972. In instances in which the release mechanism its elf is not within the occupant space of an adjacent seat, a label within the occupant space directing the occupant of the seat to the emergency exit instructions will help reduce the likelihood that the occupants would inadvertently obstruct egress throu gh the emergency exits.

NHTSA's goal of minimizing the likelihood of inadvertent obstruction of emergency exits is equally applicable to forward-facing and aisle-facing seats. However, the means of achieving that goal (i.e., placing a label within the occupant space of an adjac ent seat, if the release mechanism is not within that occupant space) may not be equally successful for forward-facing and aisle-facing seats. The agency did not focus upon aisle-facing seats when it adopted this labeling requirement. With respect to f orward-facing seats, it is relatively simple to locate a label within the occupant space that will be readily visible both to seated occupants and to persons standing in the aisle, as required by S5.5.2. However, with respect to aisle-facing seats, ther e may not be any location within the occupant space of such seats where a label could be placed so that the label would be visible to occupants of the seat and to persons standing in the aisle. If the labels were not visible in an emergency, such labels would not further NHTSA's goal of minimizing inadvertent obstruction of emergency exits.

Accordingly, we plan to issue a notice proposing to amend and clarify the requirements of S5.5.1 of Standard 217 as they apply to aisle-facing seats. Please note that, unless and until a final rule amending S5.5.1 of Standard 217 becomes effective, the c urrent requirements of S5.5.1 remain in effect for aisle-facing seats. However, the agency believes that it would be inappropriate at this time to enforce the requirement in S5.5.1 that additional information be labeled within the occupant space of aisl e-facing seats given the uncertainty that such labels will serve the purpose for which the labeling requirements were established, as noted above. Accordingly, until the agency makes a final decision on the proposed rulemaking mentioned above, NHTSA wil l not take any enforcement actions against bus manufacturers that do not place a label indicating the location of the nearest emergency exit release mechanism within the occupant space of adjacent aisle-facing seats.

ID: 2346y

Mr. R.M. Cooper
Vice President, Engineering
Gillig Corporation
Box 3008
Hayward, CA 94540-3008

Dear Mr. Cooper:

This responds to your letter asking this agency to consider a problem your company faces with respect to Standard 217, Bus Window Retention and Release (49 CFR 571.217). More specifically, you asked how some of your buses could be certified as complying with the emergency exit labeling requirements set forth in Standard 217 for buses other than school buses. I apologize for the delay in this response.

Paragraph S5.5.1 of Standard 217 provides that, in buses other than school buses, each push-out window or other emergency exit shall have the designation "Emergency Exit" followed by concise operating instructions, describing each motion necessary to unlatch and open the exit, located within 6 inches of the release mechanism. The purpose of this requirement is to identify for bus occupants the location and explain the use of specially-installed emergency exits. As I understand your letter, you have no difficulties providing appropriate instructions in the specified location.

Paragraph S5.5.1 continues with the following language:

When a release mechanism is not located within an occupant space of an adjacent seat, a label...that indicates the location of the nearest release mechanism shall be placed within the occupant space.

The terms "adjacent seat" and "occupant space" are defined in S4 of Standard 217 as follows:

"Adjacent seat" means a designated seating position located so that some portion of its occupant space is not more than 10 inches from an emergency exit, for a distance of at least 15 inches measured horizontally and parallel to the exit.

"Occupant space" means the space directly above the seat and footwell, bounded vertically by the ceiling and horizontally by the normally positioned seat back and the nearest obstruction of occupant motion in the direction the seat faces.

You stated that many of your buses have seats that face the aisle and that back up against windows designated as emergency exits. These aisle-facing seats are "adjacent seats" with respect to the emergency exits. The release mechanism for the emergency exit is not within the "occupant space" for these aisle-facing seats, since the release mechanisms are behind, not above, these seats. You enclosed a group of photographs to further illustrate this situation.

Since the release mechanism for the emergency exit is not within the occupant space of these adjacent aisle-facing seats, paragraph S5.5.1 of Standard 217 requires a label indicating the location of the release mechanism for the emergency exit to be placed within the occupant space for these seats. You have noted that the occupant space for these seats does not include any place to which this label could be attached. The nearest obstruction of occupant motion in the direction the aisle-facing seats face is the aisle facing seat on the opposite side of the bus. There are no intervening objects other than narrow vertical stanchions in the center of the aisle. Additionally, you suggested that placing the label on the floor or ceiling of the bus would not serve the purposes of this requirement, since those locations would not be readily visible to the seated occupant in an emergency situation.

In response to your letter, we have carefully considered the labeling requirements of S5.5.1 as they apply to aisle-facing seats in front of windows that serve as emergency exits. The final rule adopting this additional labeling requirement explained that NHTSA was concerned that an occupant of an adjacent seat might hinder egress through an emergency exit if the occupant did not know how to use the emergency exit. See 37 FR 9394, at 9395; May 10, 1972. In instances in which the release mechanism itself is not within the occupant space of an adjacent seat, a label within the occupant space directing the occupant of the seat to the emergency exit instructions will help reduce the likelihood that the occupants would inadvertently obstruct egress through the emergency exits.

NHTSA's goal of minimizing the likelihood of inadvertent obstruction of emergency exits is equally applicable to forward-facing and aisle-facing seats. However, the means of achieving that goal (i.e., placing a label within the occupant space of an adjacent seat, if the release mechanism is not within that occupant space) may not be equally successful for forward-facing and aisle-facing seats. The agency did not focus upon aisle-facing seats when it adopted this labeling requirement. With respect to forward-facing seats, it is relatively simple to locate a label within the occupant space that will be readily visible both to seated occupants and to persons standing in the aisle, as required by S5.5.2. However, with respect to aisle-facing seats, there may not be any location within the occupant space of such seats where a label could be placed so that the label would be visible to occupants of the seat and to persons standing in the aisle. If the labels were not visible in an emergency, such labels would not further NHTSA's goal of minimizing inadvertent obstruction of emergency exits.

Accordingly, we plan to issue a notice proposing to amend and clarify the requirements of S5.5.1 of Standard 217 as they apply to aisle-facing seats. Please note that, unless and until a final rule amending S5.5.1 of Standard 217 becomes effective, the current requirements of S5.5.1 remain in effect for aisle-facing seats. However, the agency believes that it would be inappropriate at this time to enforce the requirement in S5.5.1 that additional information be labeled within the occupant space of aisle-facing seats given the uncertainty that such labels will serve the purpose for which the labeling requirements were established, as noted above. Accordingly, until the agency makes a final decision on the proposed rulemaking mentioned above, NHTSA will not take any enforcement actions against bus manufacturers that do not place a label indicating the location of the nearest emergency exit release mechanism within the occupant space of adjacent aisle-facing seats.

Sincerely,

Stephen P. Wood Acting Chief Counsel

/ref:217 d:3/20/90

ID: 002727rbm

David Robertson, Manager
Environmental and Safety Engineering
Mazda North American Operations
1500 Enterprise Drive
Allen Park, MI 48101-2053

Dear Mr. Robertson:

This responds to your request asking whether a driver and passenger seat belt reminder system under development by Mazda would violate any Federal motor vehicle safety standards (FMVSS). Our understanding of the Mazda system, based on a meeting between staff from the National Highway Traffic Safety Administration (NHTSA) and Mazda, is that the contemplated system is designed to meet the new European New Car Assessment Program criteria for belt minders. The Mazda system, as described, is not prohibited by any FMVSS.

According to your letter, the Mazda system would consist of a reminder system that would trigger if either the driver or front passenger fails to buckle his or her seat belt by the time the vehicle reaches a forward speed of 20 km/h (12.5 mph). The reminder will not sound when the vehicle transmission is in reverse. Once triggered, the reminder system will produce an audible warning signal that will continue for 90 seconds or until the seat belts are fastened, whichever occurs first. This audible signal is indistinguishable in tone from the warning signal used by Mazda to meet the mandatory seat belt warning system required by S7.3 of FMVSS No. 208, Occupant crash protection. S7.3 of that standard requires the driver's seating position to be equipped with a seat belt warning system that activates, under specified circumstances when the seat belt is not buckled, a continuous or intermittent audible signal for a period of "not less than 4 seconds and not more than 8 seconds," and a continuous or flashing warning light for not less than 60 seconds after the ignition switch is turned on.

The prohibition on any audible signal lasting longer than 8 seconds reflects a statutory requirement imposed by Congress in response to public resistance to seat belt interlock systems. [1] 49 U.S.C. 30124 provides, in relevant part, that a motor vehicle safety standard "may not require or allow a manufacturer to comply with the standard

By using...a buzzer designed to indicate a safety belt is not in use, except a buzzer that operates only during the 8-second period after the ignition is turned to the 'start' or 'on' position."

While the statute prohibits NHTSA from requiring, or specifying as a compliance option, an audible seat belt warning that sounds outside of the specified 8-second period, it does not prohibit vehicle manufacturers from placing such systems in their vehicles. However, given FMVSS No. 208's requirement that the required seat belt warning be no longer than 8 seconds, a vehicle manufacturer wishing to provide a voluntary audible signal must provide some means of differentiating the voluntarily provided signal from the required signal. Differentiation is required so that NHTSA can definitively determine whether the warning signal meets the requirements of the standard in a compliance test.

One way to differentiate between the two signals is to utilize different sounds for each warning signal. The Mazda system, as contemplated, would not do this. Another way to differentiate between the two signals is a clearly distinguishable lapse in time between the two signals. While generally speaking, the Mazda system would provide a distinguishable lapse in time, there are instances where there may not be such a lapse under real world operating conditions.

According to your letter, the warning signal used by Mazda to meet the requirements of FMVSS No. 208 continues for six seconds from the time the ignition is turned on or until the driver's seat belt has been engaged, while the non-mandatory belt reminder system would trigger once the vehicle had reached a forward speed of approximately 12.5 mph. Under most circumstances, it is unlikely that this 12.5 mph forward speed would occur within six seconds of engaging the ignition. However, in some circumstances it would be possible to achieve this speed quickly enough to preclude a vehicle occupant from distinguishing between the two, separate warning signals.

Nevertheless, we have determined that the Mazda system would not violate S7.3 of FMVSS No. 208. The fact that, under limited circumstances, a particular vehicle occupant may be unable to distinguish between the two warning signals is not determinative. As noted above, the distinction between the two signals is needed to determine whether the mandatory signal complies with FMVSS No. 208. The Mazda system, as contemplated, will comply with S7.3 when tested in accordance with the applicable laboratory test procedure for FMVSS No. 208, TP208-12. Under that test procedure, the transmission is never moved from "park" once the ignition is engaged. Accordingly, the second, voluntary warning signal will not sound because it is only engaged once the vehicle achieves a particular forward speed. Accordingly, the system will not prevent NHTSA from clearly determining whether the requirements of S7.3 have been met.

I hope this information addresses your concerns. If you have any further questions, please feel free to contact Rebecca MacPherson of my staff at (202) 366-2992.

Sincerely,

Jacqueline Glassman
Chief Counsel

ref:208
d.5/7/03





---

[1]See H.R. Rep. No. 93-1452 (to accompany S355), at pp. 44-45 (1974), reprinted in 1974 U.S.C.C.A.N. 6108.

ID: 10166cai

Name & address withheld by request on 2/13/15

This responds to your letter asking about safety regulations for a device you call a "Cair Bag." You describe the Cair Bag as a "comfort pillow" for children to rest or sleep on while seated in their vehicle seat belt. You explain that the Cair Bag is an "under-stuffed styrene pellet bag" that attaches to the lap portion of the vehicle's Type II seat belt with a reinforced velcro and nylon strap. You state that you will recommend the product for children over 50 pounds "to prevent it from being used as a child restraint system."

By way of background information, the National Highway Traffic Safety Administration (NHTSA) has the authority to issue Federal motor vehicle safety standards for new motor vehicles and new items of motor vehicle equipment. NHTSA does not, however, approve or certify any vehicles or items of equipment. You state in your letter that everyone you spoke to at NHTSA "felt this was a great product." To avoid any possible misunderstanding about what agency personnel said about your product, I wish to clarify that NHTSA and agency personnel can not and do not endorse any product, or make commendations about products. If you understood them to say NHTSA approves of or believes your product is "great," that is incorrect, and we apologize for any confusion.

Turning now to your questions, there is currently no Federal motor vehicle safety standard (FMVSS) that directly applies to the Cair Bag. Our standard for "child restraint systems," FMVSS 213, applies to "any device except Type I or Type II seat belts, designed for use in a motor vehicle or aircraft to restrain, seat, or position children who weigh 50 pounds or less." (S4 of FMVSS 213) We do not consider the Cair Bag to "position children" in a manner that a child seat positions children to better use a vehicle's belt system. Rather, the Cair Bag is simply a cushion that a child may lean on. Since your product does not "restrain, seat, or position" children as a child restraint system, the product is not subject to Standard 213 regardless of the weight of the children for whom you recommend the product.

However, we share your concern that the Cair Bag must not be used in place of a child restraint system. We recommend that the product be clearly labeled with information to the consumer that the product is not a child restraint system and must not be used as one.

While no FMVSS applies to the Cair Bag, your product is considered to be an item of motor vehicle equipment. As a manufacturer of motor vehicle equipment, you are subject to the requirements of 49 U.S.C. ''30118-30121 concerning the recall and remedy of products with safety related defects. I have enclosed an information sheet that briefly describes those and other manufacturer responsibilities. In the event you or NHTSA determines that your product contains a safety- related defect, you would be responsible for notifying purchasers of the defective equipment and remedying the problem free of charge.

In addition, while it is unlikely that the Cair Bag would be installed by a motor vehicle manufacturer, distributor, dealer or repair business, 49 U.S.C. '30122 prohibits those businesses from installing the device if the installation "makes inoperative" compliance with any safety standard. Our FMVSS's require specific levels of performance for the belt system in a vehicle. For example, Standard 208 has requirements that ensure that a vehicle's lap and shoulder belts are installed to distribute the crash forces over the skeletal structure of the occupant. The FMVSS also have requirements for belts to automatically lock and retract, ensuring there is no excessive slack in the belt system. Since the Cair Bag attaches to the lap belt, any person listed in '30122 must ensure that compliance of the belt system with these requirements is not degraded. Also, FMVSS 302 specifies flammability resistance requirements for vehicle interiors. Any person listed in '30122 who installs a Cair Bag must ensure that the product does not vitiate the vehicle's compliance with those flammability resistance requirements.

The prohibition of '30122 does not apply to individual owners who install equipment in their own vehicles. Thus, individual owners may install any item of motor vehicle equipment regardless of its effect on compliance with Federal motor vehicle safety standards. However, NHTSA encourages vehicle owners not to degrade the safety of their vehicles.

I would like to make a further note in closing. The advertising literature you enclosed with your letter described the Cair Bag as "The Portable `Air Bag'." We believe this description could be misleading, because the term "air bag" is widely recognized as describing an inflatable device that provides substantial occupant protection in frontal impacts. We are concerned that calling your device a "portable air bag" could mislead some consumers into believing your device offers occupant protection similar to that of a vehicle air bag, which of course, is incorrect. To avoid this potential for confusion, please refrain from describing your device as an "air bag."

I hope this information has been helpful. If you have any other questions, please contact Deirdre Fujita of my staff at this address or by phone at (202) 366-2992.

Sincerely,

John Womack Acting Chief Counsel

Enclosure

ref:213 d:8/26/94 Please note that the "National Traffic and Motor Vehicle Safety Act" and the "Motor Vehicle Information and Cost Savings Act" to which the information sheet refers have recently been recodified in Title 49 of the United States Code. This means that the citations used in the information sheet are outdated; however, the substantive requirements described in the sheet have not changed.

ID: nht92-8.7

DATE: April 2, 1992

FROM: Michael F. Hecker -- Micho Industries

TO: Paul Jackson Rice -- Chief Counsel, NHTSA

COPYEE: M. Dunn; R. Rogers

TITLE: Re: R-BAR Passenger Restraint System

ATTACHMT: Attached to letter dated 5/14/92 from Paul J. Rice to Michael F. Hecker (A39; Std. 222); Also attached to letter dated 3/10/89 from Erika Z. Jones to Joseph Mikoll (Std. 222); Also attached to letter dated 1/8/90 from Jerry Ralph Curry (signed by Jeffrey R. Miller) to Robert J. Lagomarsino (Std. 222); Also attached to letter dated 1/31/91 from Paul J. Rice to Scott K. Hiler (Std. 222); Also attached to letter dated 11/3/88 from Erika Z. Jones (signed by Stephen P. Wood) to Joseph Mikoll (Std. 222)

TEXT:

As you are aware Micho Industries is the licensed manufacturer of the R-BAR passenger restraint which was developed to further the safety of children who ride in school buses. This system was designed by Safety Research and Manufacturing (SRM) of Jessup, PA.. For the last three years we have worked with SRM in the continuing development of the product in order to assure that it does not violate any applicable federal and state motor vehicle safety requirements. In addition it is our joint goal that the R-BAR establish a new standard for passenger protection in school bus transportation.

I am writing you in regards to a particular specification in 49 CFR, 571.222. As stated, the "purpose" of the standard is to reduce the number of deaths and the severity of injuries that result from the impact of school bus occupants against structures within the vehicle. We are, however, concerned with possible interpretations of the 4" seat performance rule as stated in 49 CFR, 571.222, section S5.1.2(c). With this in mind, we feel that:

A. The standard is not applicable to the R-BAR passenger restraint.

B. The R-BAR complies with the intent of 571.222.

In support for this position we offer the following reasons:

1. The R-BAR is not a fixed position device, nor is it a rigid component of the seat structure.

2. In the event of a rear impact, the R-BAR incorporates a design that allows it to move upward, and away, from the adjoining seat which would thus allow the minimum clearance as intended.

(This was proven in tests conducted in May 1991 at Calspan on their HYGE sled -- see attached Report No. 7925-1).

3. The standard in question (571.222, section S5.1.2(c) was written without the authors having the benefit of knowledge of this type of device and thus allowances were not included for its possible use.

We recognize that any final interpretation will be in the hands of your department and respectfully request your advice on this matter. We would ask that you advise us, prior to issuing a final interpretation, of any additional

concerns you may have so that we can supply the necessary information to address those concerns. In order to further aid you, we have available a test data book that summarizes the testing that the R-Bar has been subjected to, over the last seven years, and would gladly send it to you if you so desire. In addition video clips of the various tests can be assembled for you review.

Thank you in advance for your consideration in this matter.

Attachment

Calspan Advanced Technology Center SRM SLED TEST report no. 7925-1, May 20, 1991 prepared by David J. Travale, prepared for SRM, Inc. (Text and graphics omitted.)

ID: nht74-2.26

DATE: 07/09/74

FROM: AUTHOR UNAVAILABLE; R. L. Carter; NHTSA

TO: Wanger Electric Corporation

TITLE: FMVSS INTERPRETATION

TEXT: This responds to your March 12, 1974, request for interpretation of the volume requirements for service brake chambers in S5.1.2.1 and S5.2.1.2 of Standard No. 121, Air Brake Systems:

S5.1.2 Total service reservoir volume shall be at least eight times the combined volume of all service brake chambers at maximum travel of the pistons or diaphragms.

You also requested the addition of language equating brake chamber volume with brake chamber displacement, based on nominal effective area and rated stroke.

In testing for compliance with S5.1.2.1 and S5.2.1.2, the NHTSA will accept a manufacturer's published "rated volume" of the brake chamber with the piston or diaphragm at maximum travel. This means that the manufacturer may specify the full stroke of the piston or diaphragm and compute the "rated volume" based on the designed volume of the chamber and the full stroke he has established. This volume may be somewhat larger than "nominal brake chamber displacement" which does not necessarily account for the void ahead of the relaxed diaphragm or piston, the so-called "pre-fill volume". This volume must be included because it must be pressurized along with the displaced volume.

In the absence of manufacturer's published ratings, the NHTSA will measure the brake chamber volume with the push rod at maximum stroke.

Your request to add explanatory language to the standard of the measurement technique is denied as unnecessary in view of this interpretation.

Sincerely,

ATTACH.

March 12, 1974

James B. Gregory, Administrator -- National Highway Traffic Safety Administration

Re: Docket 73-13; Notice 3 74-10; Notice 1 49 CFR 571.121

Petition for Reconsideration FMVSS-121, Air Brake Systems

Dear Dr. Gregory:

We were pleased to note in the March 1, 1974, Federal Register (39FR-7966) that the NHTSA needed further consideration on petitions for air tank volume before an answer would be published.

We apparently did not place adequate emphasis on this facet of FMVSS-121 compliance. Instead of a petition, we addressed a letter dated July 13, 1973, to the Director, Office of Operating Systems, for an interpretation. In that letter we asked only one question and it is quoted below:

Will the NHTSA accept the vehicle or chamber manufacturers' nominal value for maximum allowable stroke on each actuator when determining the minimum vehicle reservoir capacity required by S5.1.2.1 and S5.2.1.2?

In view of the absence of any response to a fundamental question, the manufacturers of air-braked vehicles and air brake equipment have gone in divergent directions with their own "interpretations." Apparently, it is a more profound problem than we or our competitors anticipated. In defense of our commercial position in this product area, we now find it necessary to submit this letter as a Petition.

Petition (1) We petition for an answer to the question posed in our July 13, 1973, letter (as quoted above).

In support of this petition we have attached a copy of that letter as Appendix A. The unanswered question appears on Page 4.

We will risk being a little repetitious, but our concern is that too much emphasis is being placed on finite measurements of chamber volume and reservoir volumes. From a statistical viewpoint, the case of trailer reservoir volume is a classic example of compliance or certification "overkill." S5.2.1.2 reads:

S5.2.1.2 Total reservoir volume shall be at least eight times the combined volume of all service brake chambers at maximum travel of the pistons or diaphragms.

In mathematical terms the word "eight" has a numerical equivalent of 8. For degrees of accuracy it could be 8.0, 8.00, 8.000, --- but it was just commonplace old "number eight."

In our letter of July 13, 1973, we reproduced the SAE J813 Recommended Practice for Air Brake Reservoir Volume (see Page 2, Appendix A). A truck trailer was considered to need "not less than 4 times the actuator displacement volume at maximum travel of the piston or diaphragm." The industry has accepted this 100% improvement in stored volume. Now all we are trying to do is determine whether this gross volume can be determined by simple mathematics or will require ultra-sensitive physical measurement of the actuators and the associated reservoirs.

Not only do the simple calculations benefit the designers of vehicles and brake systems, they have an obvious benefit to the NHTSA Office of Standards Enforcement.

Does the Office of Operating Systems assign the accuracy of these measurements to four significant figures necessary to the safe operation of a trailer? We see no technical justification for this. If there is, then it should be public knowledge. This is our rationale. Again using the most popular trailer as the example: It has 2 cam brakes with type 30 (30 square inch nominal effective area) chambers for actuation. These chambers have a nominal stroke of 2 1/2 in. (one source has a 2 3/4 inch stroke).

Under SAE J813 the required reservoir volume is:

4 x (Nominal Area) x (Nominal Max. Stroke) x (No. of Chambers) = Volume or 4 (30) (2.5) (2) = 600 cubic inches.

Under S5.2.1.2 of FMVSS the simple approach is

8 (30) (2.5) (2) = 1200 cubic inches.

Now we industry specialists get concerned by public statements at NHTSA meetings that it should be easy to measure --- put it (chamber) on a table, stroke it under pressure and measure the volume.

Production tolerances may allow a maximum stroke to extend to 2.65 inches or another 8 (30) (0.15) (2) = 25 cubic inches.

A further study points out that chambers have a void ahead of the relaxed diaphragm. It is there to assure good entry of unrestricted air flow to the effective area. This pre-fill volume can be at least 5 cubic inches per chamber or (8) (5) (2) = 80 cubic inches per axle.

At full stroke the defection of the non-rigid diaphragm adds another approximate 12 cubic inches per chamber or 8 (12) (2) = 192 cubic inches per axle. It is not needed at mid-stroke. Therefore, this is a superfluous requirement. There are many other more significant factors affecting chamber/brake output if we consider brake effectiveness under such an extreme condition.

The gross addition for these three factors alone is -

25 cu. inches 80 cu. inches +192 cu. inches

297 cubic inches per axle.

Note 192 cubic inches is beyond the point of useful volume and should not be a part of this measurement anyway.

To prove compliance or non-compliance using all of the added factors would require a very sophisticated laboratory contract and allied equipment. The report would be documented by instrument calibrations and certifications traced back to the National Bureau of Standards.

Did the NHTSA really want its "doctrine of adversity" to become this costly a situation? We can't believe the task force responsible for the first issue of FMVSS-121 was that conversant with the detailed construction of chambers to recognize the disparity of viewpoints in measuring technique that have evolved. We are certain there was not one iota of data in the DOT contract files to substantiate this stringent a need. From the public meetings we recall that concern for reservoir size was subordinated in seriousness because trailers are thought to have all sorts of space for reservoirs. In some cases this is true. However, random tank placement is not possible. One other FMVSS-121 requirement makes remote tank locations impractical.

That requirement is the Brake Actuation Time found in S5.3.3. To reach 60 psi in 0.25 sec. from actuation of the test rig control requires optimum system designing --- this prohibits such luxuries as -

(a) long air lines to the chambers

(b) untested hose sizes for these line

(c) remote reservoirs to contain this superfluous volume of air.

We could not predict how essential all of this would be in 1971, but we have come a long way. It was late Spring, 1973, when we became extremely concerned about contract testing to evaluate reservoir volume. We had already acknowledged that we were part of a regulated industry. On July 13, 1973, we demonstrated our intent to act like we were being regulated and posed our "simple" question. We are disappointed that an early response was impossible to develop and furnish. We are further disappointed that the 1972 and 1973 petitions filed by a competitor on this same subject matter have not resulted in positive rulemaking actions to resolve the internal problems that must exist between the Office of Operating Systems and Office of Standards Enforcement.

Perhaps this aspect of FMVSS-121 is not as vital as decisions on the effective date, but rule content does influence ability to meet effective dates. We trust this reinforcement of open petitions will prompt immediate action.

In summary, we believe an affirmative reply to our July 13, 1973, question will not adversely affect vehicle safety. If there is any suspicion in the Office of Standards Enforcement that the vehicle manufacturers or chamber manufacturers would falsify their nominal stroke or nominal areas for these components to avoid "proper" sizing of reservoirs, then that should be a subject for docket comment. We are already charged with honest manufacturing recommendations for brake adjustment, air compressor capacity, interpretation of "controlled lockup," option choices for parking brake mode, transmission gear range, tire inflation pressure, gross vehicle weight rating, gross axle weight ratings, burnish options and others not mentioned.

Our conclusion is that the following petition will reflect a simple means for calculations:

Petition (2) We petition for the addition of this sentence to S5.2.1.2 (see Page 2): "For purposes of establishing reservoir volumes, brake chamber displacement is equal to the product of the nominal effective area and nominal rated stroke."

It may be that the relative ease of chamber and reservoir measurements makes them good "compliance targets," but if the enforcement of FMVSS-121 is reduced to such attack, the goal of the NHTSA and the efforts of the industry to attain these goals will be unjustly inhibited in future vehicle safety programs.

Very cordially yours,

WAGNER ELECTRIC CORPORATION; John W. Kourik -- Chief Engineer, Automotive Products

Attachment: Appendix A

WAGNER ELECTRIC CORPORATION WAGNER DIVISION

July 13, 1973

Elwood T. Driver, Code 41-30 -- Director, Office of Operating Systems, NHTSA

Gentlemen:

As a manufacturer of brakes and air brake actuating system components, Wagner Electric Corporation is desirous of consistent and accurate interpretations of all applicable Federal Motor Vehicle Safety Standards. We are encountering an increasing amount of confusion in the industry regarding the method or procedure to be used in establishing the air reservoir capacity for air brake vehicles as required by FMVSS-121 (Section 5.1.2.1 and Section 5.2.1.2). We are, therefore, requesting interpretation and/or clarification of these sections with regard to the wording ". . . the combined volume of all service brake chambers at maximum travel of the pistons or diaphragms . . ." as found in Sections 5.1.2.1 and 5.2.1.2.

While the method of measurement of brake actuator volume may seem insignificant, in some cases it has become a major concern to decide whether an existing reservoir volume can be used or whether a new air reservoir must be made up with a slightly larger capacity. The determining factor is how the brake actuator volume requirements are measured. Therefore, a prompt response would be most appreciated so that the design and specification of air system components required to meet FMVSS-121 can be finalized.

Prior to Docket 70-17 and Docket 70-16 work by the NHTSA the recommendation for air brake reservoir volume used by some of the vehicle manufacturers was SAE J813.

AIR BRAKE RESERVOIR VOLUME

AIR BRAKE RESERVOIR VOLUME -- SAE J813

SAE Recommended Practice

Report of Brake Committee approved November 1961

Scope -- This recommended practice establishes minimum volume requirements for air reservoirs for automotive vehicles using compressed air systems essentially for the actuation of the brake. Accessories that utilize compressed air for their operation are not included in the conventional air brake system and, therefore, additional volume must be provided for their requirements. Where air operated accessories are used, a check valve or equivalent device will be required to provide protection to the brake system.

These recommendations for minimum reservoir volumes in air brake systems are based on past experience and are intended as a guide in selecting the proper size reservoirs to assure an adequate source of braking power under normal level operating conditions.

General -- The volume of the brake actuators in the air brake system, commonly referred to as brake cylinders, brake chambers, or roto-chambers, varies with the diameter and travel of the piston or diaphragm. The reservoir volume depends upon the size and number of the actuators on the vehicle and the type of vehicle service. Recommended volumes are calculated in Table 1 by multiplying the total volume of all actuators by an experience factor. Depending on traffic conditions and terrain, reservoir volumes, greater than the minimum values, should be considered.

(Illegible Table)

This recommended practice had also been endorsed in the Final Report of the Consolidated Brake Task Force of the Joint AMA-TIMA Brake Committee dated October 28, 1965. SAE J813 was reproduced above to simplify the evaluation of the comments which follow for those individuals who were not acquainted with previous (and current) recommended practice. Note that trucks or truck-tractors required only eight (8) times the actuator displacement volume and truck-trailers only four (4) times the actuator volume. We know from our experience that the maximum travel used throughout the industry in determining actuator displacement was the nominal value for the stroke of the actuator and that there was no attempt to incorporate production variations due to manufacturing tolerances. When we compare the values for the volume in J813 with the requirements of S5.1.2.1 (trucks and buses) and S5.2.1.2 (trailers) it will be noted that significant improvement in the stored air volume has been made mandatory by FMVSS-121. There is even further significance in this change to the large volume requirement in that many vehicles were built and are being built in 1973 with reservoir capacities less than the requirements specified in J813.

Perhaps it was not recognized at the time that FMVSS-121 issued that the efficiency of brake chambers has the characteristic shown in Figure 2. The performance requirements of FMVSS-121 for (1) actual stopping distance measurements and (2) timing requirements are based on brakes being adjusted to the vehicle manufacturers' recommendation. Figure 2 demonstrates that the mid stroke of most brake chambers is the point of approximate 100% efficiency. Shorter strokes are associated with higher output than would be nominally expected. In S5.1.2.1 and S5.2.1.2 the volume of all service reservoirs and supply reservoirs is based on ". . . the combined volume of all service brake chambers at maximum travel of pistons or diaphragms." As vehicle manufacturers begin to finalize the design of the variety of systems essential to the different vehicle chassis, space for air reservoirs is precious. It is advantageous for the vehicle manufacturers and the component suppliers to select a limited number of reservoir sizes for the purposes of simplicity in design, ease of procurement, and economy of using a few standard reservoir sizes.

If the most adverse characteristics are to be determined for compliance, not only must the chambers be subjected to extremely close measurement of displacement but the net displacement of air reservoirs must be measured very precisely. We believe it is advantageous for the NHTSA to recognize that the twelve (12) and eight (8) times minimum volume requirement for trucks and trailers respectively does not require the same degree of accuracy needed to measure application and release times or to measure stopping distance compliance. We are therefore proposing that chamber strokes used in these calculations be based on the nominal values established as the maximum allowable stroke for the components installed on the vehicle. It will be noted in Figure 1 that the probable variation between a nominal stroke of 2.50" and a stroke which allows for all production tolerances is only 97.1-90.0 = 7.1 cubic inches per chamber. On a tandem axle trailer or a tandem drive axle tractor this 28 cubic inch variation has been noted to warrant an increase in the number of reservoirs essential for very precise compliance to the general requirement in Sections 5.1.2.1 and 5.2.1.2. This seems to be an unnecessary expense for the manufacturers to incur since standard reservoir volumes could be used at the lower value without any real sacrifice in vehicle performance. The slight variation in stored volume will not have any adverse effect on application time. If it did, then correction in the volume would have to be necessary in order to comply with the application time requirements for a given vehicle. We do not see that this slight volumetric difference is essential for skid control systems. It is characteristic of skid control systems to exhaust air from the service line and deplete the service reservoir(s). When skid control is functioning the performance of any system becomes self-limiting at a point at which the air pressure no longer produces sufficient brake torque to generate impending skids. Once this pressure level is achieved there is no further demand for reserve capacity in the air brake system. Therefore the stopping requirements for vehicles from 60 and 20 mph can be satisfied in the road test phase of FMVSS-121 without having to be too precise in establishing the actual net chamber/reservoir measurements.

Typical of some of the problems which can be generated by the preciseness of FMVSS-121 is the Figure 1 test rig for trailers. While 2000 cubic inch reservoirs could be obtained or could be made by modification of standard reservoir sizes, the typical unit produced in the industry is 2020 cubic inches. By using inert ballast material, a reduction of 20 cubic inches in the stored capacity of the reservoir is relatively easy. This is a case where we do not feel that a 20 cubic inch variation is really a significant part of the over-all performance requirement of either the vehicle or the test rig but the strict implementation of Figure 1 requires special equipment and added expense.

We have presented this appraisal of the situation which confronts the vendor and vehicle industry in order to provide some relief that will be of mutual benefit to the public, the vehicle manufacturers, and the NHTSA by concentrating on the critical aspects of FMVSS-121. If each phase of the Standard is put into its proper perspective it will enable the NHTSA and the industry to begin implementation of good cost/benefit practices. For this reason (Illegible Word) then ask the following:

Will the NHTSA accept the vehicle or chamber manufacturers' nominal value for maximum allowable stroke on each actuator when determining the minimum vehicle reservoir capacity required by S5.1.2.1 and S5.2.1.2?

For minor clarification, this question is directed at using (1) the middle of the three curves shown on Figure 1; (volume versus stroke at 100 psi) and (2) a volumetric requirement of 90 cubic inches at a nominal stroke of 2.50". We have encircled that point for emphasis.

Very truly yours,

John W. Kourik -- Chief Engineer, Automotive Products

Attach. Figures 1 & 2 (Graphics omitted)

ID: nht93-6.45

DATE: September 27, 1993

FROM: John Womack -- Acting Chief Counsel, NHTSA

TO: Carolyn H. McDaniel

TITLE: None

ATTACHMT: Attached to letter dated 9/1/93 from Carolyn H. McDaniel to Mary Versailles (OCC-9060)

TEXT:

This responds to your September 1, 1993, letter to Mary Versailles of my staff. You are concerned with vehicles used by a company called Extradition Services, Inc. (ESI), to transport prisoners, one of which was involved in an accident in Texas. You describe the vehicle involved in the accident as follows:

...an extended Dodge van, bars over the windows, handles off the doors, one bench in a wire cage, two more bench seats and a bench seat across the back of the van. The aisle ran along the passenger side of the van. The seats appeared to be the original seats and seat belts apparently had been removed because none were present.

You also expressed concerns related to the way these vehicles were operated.

By way of background information, the National Highway Traffic Safety Administration (NHTSA) is authorized under the National Traffic and Motor Vehicle Safety Act (15 U.S.C. S1381 et seq.; Safety Act) to issue Federal motor vehicle safety standards that apply to the manufacture and sale of new motor vehicles and new items of motor vehicle equipment. Section 108(a)(1)(A) of the Safety Act (15 U.S.C. 1397(a)(1)(A)) prohibits any person from manufacturing, introducing into commerce, selling, or importing any new motor vehicle or item of motor vehicle equipment unless the vehicle or equipment item is in conformity with all applicable safety standards. The regulations administered by this agency only address the way in which the vehicle is manufactured, not the use of the vehicle.

Based on your description of the vehicle, there may be a question as to whether the vehicle was required to have seat belts. NHTSA has exercised its authority to establish Standard No. 208, Occupant Crash Protection (49 CFR S571.208), which requires seat belts to be installed at all designated seating positions in many, but not all, vehicles. In addition, different belt installation requirements apply depending on the vehicle type, seating position within the vehicle, and the gross vehicle weight rating (GVWR) of the vehicle. Accordingly, I cannot identify the specific belt installation requirements for the vehicle in which the prisoners were transported without knowing the date of the vehicle's manufacture, the vehicle's seating capacity, and GVWR of the vehicle.

Your letter states that you believe the seat belts were removed from the vehicle after manufacture. After a vehicle's first purchase for purposes other than resale; i.e., the first retail sale of the vehicle, a provision in Federal law that affects a vehicle's continuing compliance with an applicable safety standard is set forth in section 108(a)(2)(A) of the

Safety Act (15 U.S.C. 1397(a)(2)(A)). That section provides that:

No manufacturer, distributor, dealer, or motor vehicle repair business shall knowingly render inoperative, in whole or in part, any device or element of design installed on or in a motor vehicle ... in compliance with an applicable Federal motor vehicle safety standard.

Any violation of this "render inoperative" prohibition would subject the violator to a potential civil penalty of up to $1,000 for each violation. The "render inoperative" provision would prohibit a commercial business from removing seat belts from a vehicle. Please note, however, that the "render inoperative" prohibition does not apply to modifications owners make to their own vehicles.

Your concerns about ESI's use of the vehicle are not addressed by the Federal law administered by this agency, which addresses only the manufacture and sale of motor vehicles, not their use. It is possible that there may be an issue associated with commercial driver regulations, and we have forwarded a copy of your letter to the Federal Highway Administration. In addition, because your questions concern the safety of vehicles used to transport prisoners and an accident in Texas, you may wish to contact the Governor's Office, the head of the Texas prison system, or your state representative.

I hope you find this information helpful. If you have any other questions, please contact Mary Versailles of my staff at this address or by phone at (202) 366-2992.

ID: nht75-6.26

DATE: 06/02/75

FROM: JAMES B. GREGORY -- NHTSA ADMINISTRATOR

TO: DAVID E. MARTIN -- DIRECTOR AUTOMOTIVE SAFETY ENGINEERING GENERAL MOTORS CORPORATION

TITLE: N40-30

TEXT: Dear Mr. Martin:

This responds to your December 17, 1974, and March 31, 1975, letters asking whether your proposed inertia seatback latch meets the requirements of Federal Motor Vehicle Safety Standard No. 207, Seating Systems.

After carefully examining the mechanism, considering General Motors' arguments in its favor, and meeting twice with GM representatives, we have decided that the proposed inertia latch would not comply with S4.3.1 of FMVSS 207 unless an emergency release were added to enable someone to override the automatic locking mechanism when necessary.

We agree with GM that the proposed seatback latch is an improvement in some respects over current designs. The latch provides added convenience for rear seat occupants since under normal circumstances they may fold the seat forward by simply pushing on the seatback. We also recognize that there may be a safety advantage in certain circumstances requiring fast exit from the vehicle in that the passenger will not have to fumble for a latch, which, though readily accessible, is neither in the same location nor operated in a similar manner in all cars. Your proposed design also avoids a serious problem of some current latches: namely, that they will not release if even light pressure is applied against the seatback in a forward direction. The National Highway Traffic Safety Administration is seriously considering action on this problem.

Despite these advantages, GM's proposed inertia latch would satisfy neither the intent nor the wording of S4.3.1 of FMVSS 207 because it would not release when the vehicle is upside down or upright at a pitch attitude exceeding a 32% downgrade. Such vehicle positions are not uncommon in accident situations and GM's own figures indicate that "100 rear seat occupants per year could be hindered in leaving the vehicle under circumstances which would make prompt egress important." S4.3.1 requires that "the control for releasing the (self-locking seatback) device shall be readily accessible to the occupant of the seat . . . and . . . to the occupant of the designated seating position immediately behind the seat." Under normal conditions the seatback itself would be the control for your latch and it is certainly readily accessible. When the vehicle is nose down or inverted, however, the seatback would not perform this function and there would consequently be no readily accessible control for releasing the self-locking device.

Because it is often important for passengers in post-accident situations immediately to leave or be removed from a vehicle, for any number of reasons including fire, serious bleeding or hazardous vehicle location, it seems especially important that a seatback release control operate under these circumstances. Adding an emergency latch lock override to the inertia latch design would avoid this problem while retaining the previously mentioned advantages of your design.

Sincerely,

ID: nht81-1.14

DATE: 02/19/81

FROM: AUTHOR UNAVAILABLE; F. Berndt; NHTSA

TO: United States Testing Company

TITLE: FMVSS INTERPRETATION

TEXT:

FEB 19, 1981 Mr. Frank Pepe Assistant Vice President United States Testing Company 1415 Park Avenue Hoboken, New Jersey 07030 Dear Mr. Pepe: This responds to your recent letter concerning the requirements of Safety Standard No. 209, Seat Belt Assemblies, when applied to assemblies having dual sensitive emergency locking retractors. Your specific questions relate to the low lock-up provisions of paragraph S4.3(j) of the standard. Paragraph S4.3(j) of Safety Standard No. 209 specifies the following requirements for emergency locking retractors on seat belt assemblies: (1) Shall lock before the webbing extends 1 inch when the retractor is subjected to an acceleration of 0.7g; (2) Shall not lock, if the retractor is sensitive to webbing withdrawal, before the webbing extends 2 inches when the retractor is subjected to an acceleration of 0.3g or less; (3) Shall not lock, if the retractor is sensitive to vehicle acceleration, when the retractor is rotated in any direction to any angle of 15o or less from its orientation in the vehicle.

At the time these requirements were included in the standard, emergency locking retractors were either vehicle sensitive or webbing sensitive. Recently, however, manufacturers have been producing dual sensitive retractors that are sensitive to both vehicle acceleration and webbing acceleration. You point out that dual sensitive retractors can be tested to the requirements of S4.3(j)(3) with no problem since the webbing sensitive aspect of the retractor does not interfere. However, you state that it is impossible to isolate the vehicle sensitive portion of a dual sensitive retractor in order to test to S4.3(j)(2). Accordingly, when the retractor is accelerated to .3g under the specification of (j)(2), the vehicle sensitive portion causes the retractor to lock before 2 inches of webbing have withdrawn, even though the webbing sensitive portion of the retractor would not have caused lock-up. You explain that this occurs because most retractors containing vehicle sensitive mechanisms are designed to lock-up at low "g" force levels (i.e., a tolerance is built into the retractor to ensure that it can meet the .7g requirement of subparagraph (1)). In light of this problem, you ask whether dual sensitive retractors must comply with S4.3(j)(2).

This same question was raised by Safety Transport Inter AB, Sweden, several years ago. In an October 30, 1978, letter of interpretation responding to that question, the NHTSA Associate Administrator for Rulemaking made the following statement:

"A retractor sensitive to webbing withdrawal (even if it is also sensitive to vehicle acceleration) may properly be tested for the 0.3 g comfort requirement by holding the retractor stationary and accelerating the webbing to the required g level."

That interpretation was incorrect. Paragraph S4.3(j)(2) specifically states that the retractor is to be accelerated, not the belt webbing. Further, the agency has stated in the past that accelerating the retractor and accelerating the webbing are not equivalent tests because of inertial forces that react upon the retractor during its acceleration that are not present when the webbing alone is accelerated.

The agency believes that a dual sensitive retractor should be treated simply as either a vehicle sensitive or a webbing sensitive retractor for the purposes of the standard. The intent of the agency was to require that either vehicle sensitive or webbing sensitive retractors be used. There was no expectation that dual sensitive retractors would be used and no intent that a retractor be required to meet the requirements for both types of retractors. The provision of webbing sensitivity in a retractor that meets the vehicle sensitivity requirements is a voluntary act and therefore is not subject to the standard. Likewise, the provision of vehicle sensitivity in a retractor that meets the webbing sensitive requirements is a voluntary act.

This approach will resolve the conflict that has arisen with the compliance envelopes established in S4.3(j)(1) and (j)(2), given the compliance tolerances which manufacturers are designing into newer retractors. Since vehicle sensitive mechanisms are being designed so that they activate before the .7g's required in (j)(1) is reached, the retractor locks before the webbing sensitive portion of the retractor is activated. Therefore, these dual sensitive retractors can not be tested for compliance with (j)(2).

Under this approach, a manufacturer wishing to treat its dual sensitive retractor as a vehicle sensitive retractor for the purposes of Standard No. 209 would have to comply with S4.3(j)(1) and (3). A manufacturer wishing to treat its dual sensitive retractor as a webbing sensitive retractor would have to comply with S4.3(j)(1) and (2).

I hope this has been responsive to your inquiry. If you have any further questions, please contact Hugh Oates of my office (202-426-2992).

Sincerely,

Frank Berndt Chief Counsel

October 15, 1980

Mr. Frank Berndt Chief Counsel National Highway Traffic Safety Administration 400 - 7th Street Washington, D.C. 20590

RE: FMVSS No. 209 Seat Belt Assemblies Interpretation, Emergency Locking Retractor, Lock-Up Requirement

Dear Mr. Berndt:

Some questions have been raised pertaining to the requirements for Dual Sensitive Emergency Locking Retractors when tested in accordance with FMVSS No. 209. The questions pertain to the low lock-up requirements (0.3g) Paragraph S4.3 (j).

A dual-sensitive retractor is a combination of webbing sensitive and vehicle sensitive locking mechanisms. The specifications clearly states requirements for either one of the mechanisms but does not take into account the combination of both in the same retractor. Consequently, an interpretation is needed to clarify the requirements of this type of retractor.

Our interpretation of the Standard, Para. S4.3 (j) (1) (2) and (3) as it applies to a dual-sensitive retractor is as follows:

(1) Shall lock before the webbing extends one (1) inch when the retractor is subjected to an acceleration of 0.7 g.

Comment: Applies to all types of emergency locking retractors

(2) Shall not lock, if the retractor is sensitive to webbing withdrawal, before the webbing extends two (2) inches when the retractor is subjected to an acceleration of 0.3 g or less.

Comment: Applies only to webbing sensitive type retractors. In dual sensitive retractors there is no way of isolating the vehicle sensitive portion (without disturbing an integral part of the retractor mechanism) to check the webbing sensitivity portion at 0.3 g. There is no requirement at 0.3 g for a strictly vehicle sensitive retractor. It should also be noted that most retractors containing vehicle sensitive mechanisms are designed to lock-up at low g force levels. This is to insure user confidence in the assembly during low level loading, such as braking.

(3) Shall not lock, if the retractor is sensitive to vehicle acceleration, when the retractor is rotated in any direction to any angle of 15o or less from its orientation in the vehicle.

Comment: Applies to both vehicle sensitive and dual-sensitive retractors.

I would appreciate your prompt review of the above interpretation and any comments you may have pertaining to same.

Very truly yours,

Frank Pepe Assistant Vice President Engineering Division

FP:mg

ID: nht95-2.61

TYPE: INTERPRETATION-NHTSA

DATE: May 1, 1995

FROM: John Womack -- Acting Chief Counsel, NHTSA

TO: Charles Tucker

TITLE: NONE

ATTACHMT: ATTACHED TO 3/21/95 LETTER FROM CHARLES TUCKER TO GAYLE D. DALRYMPLE (OCC 10822)

TEXT: Dear Mr. Tucker:

This responds to your letter of March 21, 1995, requesting a letter stating that your van can be modified by replacing "the factory installed steering wheel with the smaller ASTECH steering wheel without an air bag." Your letter explains that your range- of-motion is limited from multiple sclerosis and that the smaller steering wheel improves your ability to drive. During a March 31, 1995 phone call with Mary Versailles of my staff you explained that the van is also equipped with a wheelchair lift and t hat the floor of the vehicle has been lowered. As explained in this letter, replacement of your steering wheel is permitted provided that a lap/shoulder safety belt is installed at the driver's position.

By way of background, the National Highway Traffic Safety Administration is authorized to issue Federal Motor Vehicle Safety Standards that set performance requirements for new motor vehicles and items of motor vehicle equipment. Manufacturers are requir ed to certify that their products conform to all applicable safety standards before they can be offered for sale. If a certified vehicle is modified, other than by the addition, substitution, or removal of readily attachable components, prior to its fir st retail sale, the person making the modification is an alterer and is required to certify that, as altered the vehicle continues to conform to all applicable safety standards.

After the first retail sale, there is one limit on modifications made to vehicles. 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 safety standard. In general, the "make inoperative" prohibition would require a business which modifies motor vehicles to ensure that they do not remove, disconnect, or degrade the performance of safety equipment installed in compliance with an applicable safety standard.

NHTSA has exercised its authority to issue Standard No. 208, Occupant Crash Protection. Standard No. 208 requires light trucks and vans manufactured on or after September 1, 1991 to be capable of providing occupant crash protection to front seat occupant s when the vehicle is crash tested at 30 miles per hour (mph) into a concrete barrier. A vehicle that provides this crash protection will increase the safety of vehicle occupants. The air bag installed in your van is one means of complying with this re quirement.

As a result of this new requirement, this agency received a number of phone calls and letters, from both van converters and individuals like yourself, suggesting that the new light truck and van crash testing requirement will, in effect, prohibit van con verters from modifying vehicles to accommodate the special needs of persons in wheelchairs. The agency also received a petition asking for an amendment to the light truck and van crash test requirement in Standard No. 208 to address this problem.

As a result on that petition, on March 2, 1993, this agency amended Standard No. 208 to allow manufacturers of light trucks and vans an alternative to complying with the existing requirement. Under the amendment, "vehicles manufactured for operation by persons with disabilities" are excluded from the light truck and van automatic crash protection requirement. Instead, these vehicles must be equipped with a Type 2 manual belt (integrated lap and shoulder belt) or Type 2A manual belt (non-integrated lap and shoulder belt) at the front outboard seating positions. n1 A "vehicle manufactured for operation by persons with disabilities" is defined as

vehicles that incorporate a level change device (e.g., a wheelchair lift or a ramp) for onloading or offloading an occupant in a wheelchair, an interior element of design intended to provide the vertical clearance necessary to permit a person in a wheelc hair to move between the lift or ramp and the driver's position or to occupy that position, and either an adaptive control or special driver seating accommodation to enable persons who have limited use of their arms or legs to operate a vehicle. For pur poses of this definition, special driver seating accommodations include a driver's seat easily removable with means installed for that purpose or with simple tools, or a driver's seat with extended adjustment capability to allow a person to easily transf er from a wheelchair to the driver's seat.

n1 The March 2 final rule was further amended on May 18, 1994 to allow the installation of Type 2A manual belts.

Based on the information you provided, your van would come within this definition. Therefore, if the modifier of your van would be considered an alterer, it may certify that, with the air bag removed, the vehicle continues to conform to all applicable s afety standards, provided that the safety belts are not removed. If the modification is done after the first retail sale, removal of the air bag would not violate the "make inoperative" prohibition, provided that the safety belts are not removed.

I hope this information has been helpful. I have also forwarded a copy of this letter to the modifier indicated in your letter. If you have other questions or need some additional information, please contact Mary Versailles at this address or by phone at (202) 366-2992.