ID: aiam1735

Dear Mr. Danis: This is in response to your letter of October 23, 1974, requesting ou comments on your West Coast type mirror (which includes a ground-in convex spot mirror) and information on Federal regulations for spot mirrors in general.; Standard No. 111, *Rearview Mirrors*, provides minimum performanc requirements for rearview mirrors on passenger cars and multipurpose passenger vehicles. According to the standard, the outside rearview mirror required to be placed on the driver's side of the vehicle must be furnish the driver with a specified field of view to the rear of substantially unit magnification. As long as the mirror is capable of satisfying these field view requirements, the inclusion of a convex spot mirror no the plane mirror (as with the West Coast mirror) is not prohibited by the standard. If your West Coast type mirror is capable of providing the required view of substantially unit magnification independent of its convex spot mirror, it will comply with the standard.; The recent notice proposing to amend the rearview mirror standard (Ma 1, 1974, 39 FR 15143), does not alter the above described permissible use of West Coast type mirrors. No requirements for spot mirrors are contained in the Federal motor vehicle safety standards.; We appreciate your interest. Yours truly, Richard B. Dyson, Acting Chief Counsel

ID: 2874o

Mr. Donald Friedman
President
Liability Research, Inc.
4448 Via Esperanza
Santa Barbara, CA 93110

Dear Mr. Friedman:

This is a response to your letter dated November 17, 1987, asking whether two child restraint systems you have designed comply with certain requirements of Federal motor vehicle safety standard 213, Child Restraint Systems. You call one system "Cradle Safe," and describe it as an inclined, rear-facing, deformable, vinyl-covered woodfiber board carrier designed to restrain new-born infants from 4.5 to 14 lbs. The second system you call "Premie Cradle," and describe it as a recumbent, rear-facing, deformable, vinyl-covered woodfiber board carrier designed for premature infants from 4 to 6 lbs.

Your letter assesses the performance attributes of these systems as follows:

"In an accident the baby is oriented and cushioned to avoid injury and ejection by a deformable, energy absorbing 'bed' and 'shell' without harnessing the infant.

The bed and its crushable extensions (wings) cause the infant to rotate and take acceleration forces through its back and limit those applied to the head. After rotation, the infant is cushioned by the collapsing bed."

You state your belief that both systems comply with applicable provisions of Standard 213, but ask for our comment because "the designs are innovative and make the applicability and interpretation of certain paragraphs of the standard not entirely obvious." To help the agency better understand your products and the methods you used to test performance, you requested that agency staff meet with you, and your colleague, Mr. David Shinn.

On April 12, 1988, a meeting was held with you, Mr. Shinn, and agency staff from the following offices: Chief Counsel, Enforcement, Plans and Policy, Research and Development, Rulemaking, and Traffic Safety Programs. At that meeting, you and Mr. Shinn presented a video-film showing two sled-tests of your cradle-safe restraint system, one with a NHTSA-specified, 17 pound dummy, and one with an EEC eight pound dummy. In the video film, your child restraint system broke apart in the 30 mph test with the 17 pound dummy, but appeared to maintain its structural integrity when tested with the eight pound dummy. You did not show a sled-test with your "Premie Cradle" product.

By a letter dated June 8, 1988, you informed this agency that you had performed tests of a "modified" Cradle-Safe restraint system, and that this system will contain the NHTSA-specified 17 pound dummy in simulated barrier-impact testing under Standard 213. You state further that a restraint system you call "One-ride" also will contain a 17 pound dummy in Standard 213 testing. (You did not address the "One-ride" restraint in your November 17, 1987, correspondence, nor did you present it during the April 12, 1988 meeting.) Your June 8 letter also references a letter of July 22, 1987, addressed to Mr. Val Radovich of this agency; a June 3, 1988 video tape showing a simulated barrier impact test of your Cradle-Safe seat with a 17 pound dummy; and submissions of patent documents in support of a patent application for your products.

As NHTSA staff understood from your November 17, 1987 letter, and the April 12, 1988 meeting, your principal question was whether you could test a Standard 213 child restraint system with an eight or 14 pound dummy (rather than the specified 17 pound dummy), if you intended to label the restraint as appropriate for children from 4.5 to 10 pounds. You briefly addressed the other matters raised in your November 17, letter, clarifying a reference to an "unspecified belt provided for use outside the vehicle and not required in (Standard 213) testing." You explained that the "belt" to which you refer is a two-piece, cloth wrap that anchors at either side of the restraint, and fastens over the child with a velcro attachment.

I shall respond to your comments in the order that you present them in your letter, also discussing new matters raised in the meeting, in the June 8, 1988 letter, and in your other submissions where appropriate. I will not discuss the patent materials because they are not relevant to a determination of whether your restraint systems comply with Standard 213. In responding to your comments, I assume that we are discussing only those child restraint systems designed for children weighing less than 20 pounds (infant restraints).

Your First Comment. Paragraph 5.1.1.a dealing with Child Restraint System Integrity specifies "no complete...and no partial separation" of surfaces. Our design is deformable and involves materials of 1/4" thickness which in deforming, tear slightly. However when torn these materials are not lacerating and not likely to come into contact with the infant.

Response. Paragraph S5.1.1(a) states that when a child restraint is tested as specified in the Standard, the system shall:

Exhibit no complete separation of any load bearing structural element and no partial separation exposing either surfaces with a radius of less than 1/4 inch or surfaces with protrusions greater than 3/8 inch above the immediate adjacent surrounding contactable surface of any structural element of the system.

If the system failure you describe as tearing of materials at the system surface does not result in a failure of the load-bearing structure of the system, then paragraph S5.1.1(a) is inapplicable. In 1978, NHTSA proposed adding this language to 213 as one of a number of amendments to the Standard that would upgrade performance requirements, improve performance criteria, and require dynamic testing of child restraint systems using anthropomorphic test dummies. (43 FR 21470, 21473, May 18, 1978.) In the preamble of that document, we stated that our objectives in promulgating the system integrity requirements were to prevent a child's excessive excursion or ejection from the system, and to ensure that the system does not fracture or separate in such a way as to harm the child. (43 FR 21470, 21473.)

To accomplish this objective, Standard 213 requires that in dynamic testing, any load-bearing, structural element of a child restraint system must not separate completely; and that any partial separation must not expose surfaces with sharp edges that may contact the child. Id. Your letter states that some materials at the surface of your system may tear during an impact. In promulgating S5.1.1(a), the agency intended to minimize dangers resulting from failures in the structural integrity of the system, rather than failures in the materials. The agency did not intend to preclude a manufacturer from designing some deformation into a child restraint system to improve the system's energy absorption performance.

Your Second Comment. Paragraph 5.2.3.2.b The system surface in contact with the infant's head shall be covered with slow recovery, energy absorbing material. Although our system surfaces are not covered, they are fabricated out of such material. The system surface in contact with the infants head (the bed) is 3/16" woodfiber separated by air from a similar material in the shell. The system complies with the requirement and when dynamically tested exhibits deformation much better than a 25% compression-deflection, but there is no appropriate ASTM Test Standard such as for open or closed cell foam.

Response. As I read your comment, you raise three issues which I shall address separately. The first is whether the material from which you fabricate your system can meet the S5.2.3.2(b) requirement that a child restraint system must be "covered" with slow recovery, energy absorbing material. The agency's long-standing position is that a given type of surface material is an acceptable "covering" if it is a flexible material that would meet the thickness and performance requirements for energy-absorbing padding set out in paragraphs (a) and (b) of S5.2.3.2. The surface needn't have a separate layer of energy-absorbing padding.

The second issue is whether 3/16 inch woodfiber is a sufficient thickness for a system surface. This thickness would not comply with S5.2.3.2(b) of Standard 213. That subparagraph requires thicknesses of at least 1/2 or 3/4 inch, depending on the material's compression-deflection performance as measured in the static testing specified in S6.3 of Standard 213.

You assert that the 3/16 inch thickness material used in your systems exceeds a 25% compression-deflection measurement in dynamic testing. In the preamble to the final rule amending Standard 213, NHTSA responded to commenters who suggested that specifying a minimum thickness for the infant restraint surface was design-restrictive. (44 FR 72131, 72135, December 13, 1979.) We explained in that document that we set these minimum thickness requirements because there was no available test device to measure the energy absorption properties of either the surface or underlying structure of an infant restraint in dynamic testing. Consequently, the agency specified "long-established static tests" of the surface material, and established minimum thickness requirements based on the results of those static tests. Therefore, a compression-deflection measurement derived from dynamic testing is not an acceptable test of compliance with paragraph S5.2.3.2.

The third issue is whether the compression-deflection measurement for this system must be derived from tests under one of the ASTM standards in S6.3, even though none of the ASTM titles expressly states that the test is for woodfiber, and all three procedures are for static tests. Paragraph S5.2.3.2(b) requires that when one tests the energy absorption properties of child restraint materials, those tests must be conducted under one of three ASTM static test procedures set out in paragraph S6.3 of Standard 213.

Your restraint systems are made of woodfiber. Woodfiber - or any material that meets the Standard's requirements - can be an acceptable substance out of which to fabricate a child restraint. As NHTSA stated in the final rule preamble cited earlier, the agency wishes to allow restraint manufacturers to use a wide range of materials, provided that the material exhibits acceptable energy absorption properties. You may use any ASTM title specified in paragraph S6.3 to test your surface material, and the material is acceptable if it displays the required energy absorption properties when tested under one of those titles.

Your Third Comment. Paragraph 5.4.3.1 "Each belt that is part of a child restraint system and that is designed to restrain a child using the system..." is interpreted to mean that a soft unspecified belt provided for use outside the vehicle and not required in testing, need not conform to this paragraph.

Response. As you explained in the April 12, meeting, the "belt" to which you refer is the cloth device described in the beginning of this letter. By its express terms, paragraph S5.4.3.1 is inapplicable to belts that are (1) not part of the child restraint system and (2) not designed to restrain a child using the system. On the other hand, I note that in the June 8, video tape, the narrative refers to a belt within the Cradle-Safe system as a belt for restraining the child. If you do intend any belt in the system to be used for restraining the child, then various provisions of paragraph S5.4.3, Belt Restraint, will apply, depending on the design configuration of the belt assembly.

In the preamble to the May 1978 proposal cited earlier in this letter, the agency expressed its continuing concern that child restraint system designs minimize the prospect of system misuse. (43 FR 21470, 21471.) If there are belts in any of your child restraint systems that you do not intend as restraints for the child, then I hope you will consider whether these additional belts unreasonably increase the risk that some users will mistake the additional belt assembly as a Standard 213 belt intended for use in restraining a child.

Your Fourth Comment. Paragraph 6. This paragraph requires the CRADLE SAFE to be tested with a paragraph 7 dummy (17 lb.) for which it was not designed and which cannot be physically accommodated. We would prefer to use available 7.8 lb. and/or 14 lb. non-specified dummies. The PREMIE CRADLE falls in the car bed "travel crib" category and does not require dynamic testing.

Response. Paragraph S7.1 of Standard 213 requires testing an infant restraint system with the 6-month-old dummy specified in 49 CFR 572.25. (An infant restraint system is one that is recommended "for use by children in a weight range that includes children weighing not more than 20 pounds.") That test device is 17.4 pounds. Because your child safety system meets the definition of infant restraint, it must be capable of meeting Standard 213 performance requirements when tested with the specified 17.4 pound dummy. If an infant restraint can not accommodate this test device, then it can not be certified as complying with Standard 213. I understand from your June 8, 1988, letter that the Cradle-Safe and One-Ride systems will accommodate the specified 17.4 pound dummy in Standard 213 testing. Further, your restraint systems must meet head excursions limits with the 17.4 pound dummy under paragraph S5.1.3.2, Rear-facing Child Restraint Systems.

The dummy specified in Part 572 is based on a simple design that represents a 6-month-old infant in dimensional, mass distribution, and dynamic response characteristics. NHTSA chose to use this test dummy after conducting extensive testing and evaluation of the dummy's responses. The testing, conducted by NHTSA and the Federal Aviation Administration (FAA), showed that the specified dummy provided a consistent and repeatable measure of the structural integrity and confinement properties of a child restraint system, and was superior to a previous test version. (43 FR 21490, May 18, 1978; 44 FR 76527, December 27, 1979.) Before we can sanction use of another device to test an infant restraint system, the agency would have to determine that the dummy is a reliable surrogate for measuring a system's performance in an actual crash. NHTSA can not now make that statement with respect to any unspecified dummy, instrumented or non-instrumented. The agency can make this kind of finding only through a rulemaking process.

Further, contrary to what you believe, infant car beds are subject to dynamic testing to ensure that the test dummy stays within the confines of the restraint system during impact. (Standard 213, S6.1.2.3.3.)

While you believe you have identified some potential problems with Standard 213, I am sure that you can appreciate the need to follow established procedures when considering any change to a safety standard. Following established practices helps ensure that child restraint systems which comply with Federal standards continue to offer satisfactory crash protection for children. The agency has scheduled two public meetings this summer in order to explore the need for changes to Standard 213. I enclose a copy of the notice announcing these meetings, and invite you to participate in the forum.

Based on the information you provided, it appears that you would have to modify your systems, or the agency would have to amend Standard 213 in order for you to be able to certify your child restraint system as satisfying all the applicable requirements of that Standard. Title 49 CFR Part 552, Petitions for Rulemaking, Defect, and Noncompliance Orders (copy enclosed) sets out a procedure for petitioning the agency to amend a safety standard, and you have a right to file such a petition. If NHTSA grants your petition, the agency would follow its normal rulemaking procedures to amend Standard 213.

If you have some further questions or need further information on this subject, please contact Joan Tilghman of my staff at our address, or telephone (202) 366-2992.

Sincerely,

Erika Z. Jones Chief Counsel

Enclosures ref:213 d:7/8/88

ID: nht88-2.63

TYPE: INTERPRETATION-NHTSA

DATE: 07/08/88 EST

FROM: ERIKA Z. JONES -- CHIEF COUNSEL, NHTSA

TO: DONALD FRIEDMAN -- PRESIDENT-LIABILITY RESEARCH, INC.

TITLE: NONE

TEXT: This is a response to your letter dated November 17, 1987, asking whether two child restraint systems you have designed comply with certain requirements of Federal motor vehicle safety standard 213, Child Restraint Systems. You call one system "Cradle S afe," and describe it as an inclined, rear-facing, deformable, vinyl-covered woodfiber board carrier designed to restrain new-born infants from 4.5 to 14 lbs. The second system you call "Premie Cradle," and describe it as a recumbent, rear-facing, defor mable, vinyl-covered woodfiber board carrier designed for premature infants from 4 to 6 lbs.

Your letter assesses the performance attributes of these systems as follows:

"In an accident the baby is oriented and cushioned to avoid injury and ejection by a deformable, energy absorbing 'bed' and 'shell' without harnessing the infant.

The bed and its crushable extensions (wings) cause the infant to rotate and take acceleration forces through its back and limit those applied to the head. After rotation, the infant is cushioned by the collapsing bed."

You state your belief that both systems comply with applicable provisions of Standard 213, but ask for our comment because "the designs are innovative and make the applicability and interpretation of certain paragraphs of the standard not entirely obviou s." To help the agency better understand your products and the methods you used to test performance, you requested that agency staff meet with you, and your colleague, Mr. David Shinn.

On April 12, 1988, a meeting was held with you, Mr. Shinn, and agency staff from the following offices: Chief Counsel, Enforcement, Plans and Policy, Research and Development, Rulemaking, and Traffic Safety

Programs. At that meeting, you and Mr. Shinn presented a video-film showing two sled-tests of your cradle-safe restraint system, one with a NHTSA-specified, 17 pound dummy, and one with an EEC eight pound dummy. In the video film, your child restraint system broke apart in the 30 mph test with the 17 pound dummy, but appeared to maintain its structural integrity when tested with the eight pound dummy. You did not show a sled-test with your "Premie Cradle" product.

By a letter dated June 8, 1988, you informed this agency that you had performed tests of a "modified" Cradle-Safe restraint system, and that this system will contain the NHTSA-specified 17 pound dummy in simulated barrier-impact testing under Standard 21 3. You state further that a restraint system you call "One-ride" also will contain a 17 pound dummy in Standard 213 testing. (You did not address the "One-ride" restraint in your November 17, 1987, correspondence, nor did you present it during the Apri l 12, 1988 meeting.) Your June 8 letter also references a letter of July 22, 1987, addressed to Mr. Val Radovich of this agency; a June 3, 1988 video tape showing a simulated barrier impact test of your Cradle-Safe seat with a 17 pound dummy; and submiss ions of patent documents in support of a patent application for your products.

As NHTSA staff understood from your November 17, 1987 letter, and the April 12, 1988 meeting, your principal question was whether you could test a Standard 213 child restraint system with an eight or 14 pound dummy (rather than the specified 17 pound dum my), if you intended to label the restraint as appropriate for children from 4.5 to 10 pounds. You briefly addressed the other matters raised in your November 17, letter, clarifying a reference to an "unspecified belt provided for use outside the vehicl e and not required in (Standard 213) testing." You explained that the "belt" to which you refer is a two-piece, cloth wrap that anchors at either side of the restraint, and fastens over the child with a velcro attachment.

I shall respond to your comments in the order that you present them in your letter, also discussing new matters raised in the meeting, in the June 8, 1988 letter, and in your other submissions where appropriate. I will not discuss the patent materials b ecause they are not relevant to a determination of whether your restraint systems comply with Standard 213. In responding to your comments, I assume that we are discussing only those child restraint systems designed for children weighing less than 20 po unds (infant restraints).

Your First Comment. Paragraph 5.1.1.a dealing with Child Restraint System Integrity specifies "no complete . . . and no partial separation" of surfaces. Our design is deformable and involves materials of 1/4" thickness which in deforming, tear slight ly. However when torn these materials are not lacerating and not likely to come into contact with the infant.

Response. Paragraph S5.1.1(a) states that when a child restraint is tested as specified in the Standard, the system shall:

Exhibit no complete separation of any load bearing structural element and no partial separation exposing either surfaces with a radius of

less than 1/4 inch or surfaces with protrusions greater than 3/8 inch above the immediate adjacent surrounding contactable surface of any structural element of the system.

If the system failure you describe as tearing of materials at the system surface does not result in a failure of the load-bearing structure of the system, then paragraph S5.1.1(a) is inapplicable. In 1978, NHTSA proposed adding this language to 213 as o ne of a number of amendments to the Standard that would upgrade performance requirements, improve performance criteria, and require dynamic testing of child restraint systems using anthropomorphic test dummies. (43 FR 21470, 21473, May 18, 1978.) In the preamble of that document, we stated that our objectives in promulgating the system integrity requirements were to prevent a child's excessive excursion or ejection from the system, and to ensure that the system does not fracture or separate in such a wa y as to harm the child. (43 FR 21470, 21473.) To accomplish this objective, Standard 213 requires that in dynamic testing, any load-bearing, structural element of a child restraint system must not separate completely; and that any partial separation must not expose surfaces with sharp edges that may contact the child. Id. Your letter states that some materials at the surface of your system may tear during an impact. In promulgating S5.1.1(a), the agency intended to minimize dangers resulting from failures in the structural integrity of the syste m, rather than failures in the materials. The agency did not intend to preclude a manufacturer from designing some deformation into a child restraint system to improve the system's energy absorption performance.

Your Second Comment. Paragraph 5.2.3.2.b The system surface in contact with the infant's head shall be covered with slow recovery, energy absorbing material. Although our system surfaces are not covered, they are fabricated out of such material. Th e system surface in contact with the infants head (the bed) is 3/16" woodfiber separated by air from a similar material in the shell. The system complies with the requirement and when dynamically tested exhibits deformation much better than a 25% compre ssion-deflection, but there is no appropriate ASTM Test Standard such as for open or closed cell foam.

Response. As I read your comment, you raise three issues which I shall address separately. The first is whether the material from which you fabricate your system can meet the S5.2.3.2(b) requirement that a child restraint system must be "covered" with slow recovery, energy absorbing material. The agency's long-standing position is that a given type of surface material is an acceptable "covering" if it is a flexible material that would meet the thickness and performance requirements for energy-absorbi ng padding set out in paragraphs (a) and (b) of S5.2.3.2. The surface needn't have a separate layer of energy-absorbing padding.

The second issue is whether 3/16 inch woodfiber is a sufficient thickness for a system surface. This thickness would not comply with S5.2.3.2(b) of Standard 213. That subparagraph requires thicknesses of at least 1/2 or 3/4 inch, depending on the mater ial's compression-deflection

performance as measured in the static testing specified in S6.3 of Standard 213.

You assert that the 3/16 inch thickness material used in your systems exceeds a 25% compression-deflection measurement in dynamic testing. In the preamble to the final rule amending Standard 213, NHTSA responded to commenters who suggested that specifyi ng a minimum thickness for the infant restraint surface was design-restrictive. (44 FR 72131, 72135, December 13, 1979.) We explained in that document that we set these minimum thickness requirements because there was no available test device to measure the energy absorption properties of either the surface or underlying structure of an infant restraint in dynamic testing. Consequently, the agency specified "long-established static tests" of the surface material, and established minimum thickness requ irements based on the results of those static tests. Therefore, a compression-deflection measurement derived from dynamic testing is not an acceptable test of compliance with paragraph S5.2.3.2.

The third issue is whether the compression-deflection measurement for this system must be derived from tests under one of the ASTM standards in S6.3, even though none of the ASTM titles expressly states that the test is for woodfiber, and all three proce dures are for static tests. Paragraph S5.2.3.2(b) requires that when one tests the energy absorption properties of child restraint materials, those tests must be conducted under one of three ASTM static test procedures set out in paragraph S6.3 of Stand ard 213.

Your restraint systems are made of woodfiber. Woodfiber - or any material that meets the Standard's requirements - can be an acceptable substance out of which to fabricate a child restraint. As NHTSA stated in the final rule preamble cited earlier, the agency wishes to allow restraint manufacturers to use a wide range of materials, provided that the material exhibits acceptable energy absorption properties. You may use any ASTM title specified in paragraph S6.3 to test your surface material, and the material is acceptable if it displays the required energy absorption properties when tested under one of those titles.

Your Third Comment. Paragraph 5.4.3.1 "Each belt that is part of a child restraint system and that is designed to restrain a child using the system..." is interpreted to mean that a soft unspecified belt provided for use outside the vehicle and not r equired in testing, need not conform to this paragraph.

Response. As you explained in the April 12, meeting, the "belt" to which you refer is the cloth device described in the beginning of this letter. By its express terms, paragraph S5.4.3.1 is inapplicable to belts that are (1) not part of the child re straint system and (2) not designed to restrain a child using the system. On the other hand, I note that in the June 8, video tape, the narrative refers to a belt within the Cradle-Safe system as a belt for restraining the child. If you do intend any b elt in the system to be used for restraining the child, then various provisions of paragraph S5.4.3, Belt Restraint, will apply, depending on the design configuration of the belt assembly.

In the preamble to the May 1978 proposal cited earlier in this letter, the agency expressed its continuing concern that child restraint system designs minimize the prospect of system misuse. (43 FR 21470, 21471.) If there are belts in any of your child restraint systems that you do not intend as restraints for the child, then I hope you will consider whether these additional belts unreasonably increase the risk that some users will mistake the additional belt assembly as a Standard 213 belt intended fo r use in restraining a child.

Your Fourth Comment. Paragraph 6. This paragraph requires the CRADLE SAFE to be tested with a paragraph 7 dummy (17 lb.) for which it was not designed and which cannot be physically accommodated. We would prefer to use available 7.8 lb. and/or 14 l b. non-specified dummies. The PREMIE CRADLE falls in the car bed "travel crib" category and does not require dynamic testing.

Response. Paragraph S7.1 of Standard 213 requires testing an infant restraint system with the 6-month-old dummy specified in 49 CFR @ 572.25. (An infant restraint system is one that is recommended "for use by children in a weight range that includes ch ildren weighing not more than 20 pounds.") That test device is 17.4 pounds. Because your child safety system meets the definition of infant restraint, it must be capable of meeting Standard 213 performance requirements when tested with the specified 17. 4 pound dummy. If an infant restraint can not accommodate this test device, then it can not be certified as complying with Standard 213. I understand from your June 8, 1988, letter that the Cradle-Safe and One-Ride systems will accommodate the specifie d 17.4 pound dummy in Standard 213 testing. Further, your restraint systems must meet head excursions limits with the 17.4 pound dummy under paragraph S5.1.3.2, Rear-facing Child Restraint Systems.

The dummy specified in Part 572 is based on a simple design that represents a 6-month-old infant in dimensional, mass distribution, and dynamic response characteristics. NHTSA chose to use this test dummy after conducting extensive testing and evaluatio n of the dummy's responses. The testing, conducted by NHTSA and the Federal Aviation Administration (FAA), showed that the specified dummy provided a consistent and repeatable measure of the structural integrity and confinement properties of a child res traint system, and was superior to a previous test version. (43 FR 21490, May 18, 1978; 44 FR 76527, December 27, 1979.) Before we can sanction use of another device to test an infant restraint system, the agency would have to determine that the dummy i s a reliable surrogate for measuring a system's performance in an actual crash. NHTSA can not now make that statement with respect to any unspecified dummy, instrumented or non-instrumented. The agency can make this kind of finding only through a rulem aking process.

Further, contrary to what you believe, infant car beds are subject to dynamic testing to ensure that the test dummy stays within the confines of the restraint system during impact. (Standard 213, S6.1.2.3.3.)

While you believe you have identified some potential problems with Standard 213, I am sure that you can appreciate the need to follow established procedures when considering any change to a safety standard.

Following established practices helps ensure that child restraint systems which comply with Federal standards continue to offer satisfactory crash protection for children. The agency has scheduled two public meetings this summer in order to explore the need for changes to Standard 213. I enclose a copy of the notice announcing these meetings, and invite you to participate in the forum.

Based on the information you provided, it appears that you would have to modify your systems, or the agency would have to amend Standard 213 in order for you to be able to certify your child restraint system as satisfying all the applicable requirements of that Standard. Title 49 CFR Part 552, Petitions for Rulemaking, Defect, and Noncompliance Orders (copy enclosed) sets out a procedure for petitioning the agency to amend a safety standard, and you have a right to file such a petition. If NHTSA grant s your petition, the agency would follow its normal rulemaking procedures to amend Standard 213.

If you have some further questions or need further information on this subject, please contact Joan Tilghman of my staff at our address, or telephone (202) 366-2992. ENCLOSURES

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: aiam3371

Dear Mr. Mulligan: This is in response to your letter of October 1, 1980, in which you as whether compliance with 49 CFR 567, Certification, will satisfy the requirements of S4.3 of Federal Motor Vehicle Safety Standard No. 115, 49 CFR 571.115.; Section 4.3 of Federal Motor Vehicle Safety Standard No. 115 require that the vehicle identification number (VIN) 'appear clearly and indelibly upon either a part of the vehicle other than the glazing that is not designed to be removed except for repair or upon a separate plate or label which is permanently affixed to such a part.' S4.3.1 requires each character to appear in a capital, sans serif typeface. In the case of passenger cars and trucks of 10,000 pounds or less GVWR, each character must have a minimum height of 4 mm. S4.4 specifies that the VIN for passenger cars and trucks of 10,000 pounds or less GVWR shall be located within the passenger compartment.; Section 567.4 of Part 567, Certification (49 CFR 567), requires tha the certification label be permanently affixed to the vehicle, and display the vehicle identification number. Consequently, for all vehicles except passenger cars and trucks of 10,000 pounds or less GVWR, compliance with S 567.4 of Part 567 would also effect compliance with S4.3 of Standard No. 115 so long as capital, sans serif typeface was used.; Sincerely, Frank Berndt, Chief Counsel

ID: aiam2624

Dear Mr. McNeil: This responds to your May 25, 1977, letter asking whether two sampl certification labels you submitted comply with the requirements of Part 567, *Certification*, and Standard No. 120, *Tire Selection and Rims for Motor Vehicles Other Than Passenger Cars*.; The National Highway Traffic Safety Administration (NHTSA) does no issue advance approvals of compliance with Federal safety standards or regulations. The agency will, however, give you an informal opinion as to whether your labels appear to comply with the requirements. The two labels you submitted do not follow the format required by Part 567 for certification labels. Therefore, they do not appear to comply with the requirements. Your method of stating tire and rim sizes differs from that required in Part 567 and Standard No. 120. For example, you state your tire and rim information as follows: '10-20-F-Tires-7.5 Rims at 75 PSI Cold Dual.' By the requirements of Part 567 and Standard No. 120 as they apply to certification labels, this information should read: '10.00-20(F) tires, 20x7.5 rims, at 75 psi cold dual.' Further, the statement after GAWR 'maximum with minimum size tire-rims shown below' should be deleted from the certification label. I am enclosing a copy of Part 567 and Standard No. 120 for your information.; Sincerely, Joseph J. Levin, Jr., Chief Counsel

ID: aiam0938

Dear Mr. O'Meara: Thank you for your letter of 29 November, 1972, concerning allege non-compliance of the Defect Information Report regarding Volkswagen Windshield Wipers, submitted by Volkswagen of America on October 12, 1972, with the requirements of NHTSA's Defect Reports Regulations, 49 CFR Part 573. We agree that Volkswagen has failed to supply information required by Sections 573.4(c)(2) and 573.4(c)(6) of the Regulation, specifically, the months of manufacture of the affected vehicles and a chronology which includes warranty claims, field service bulletins, and other such information. We are contacting Volkswagen to determine why the Company has failed to furnish that information and to attempt to obtain it. We also agree with your conclusion that 100% of 1948-1969 Volkswagens are potentially affected by the windshield wiper defect. However, Volkswagen's statement that 'no information is available' as to either the total number of such vehicles operating in the United States, or the percentage potentially affected satisfies the disclosure requirement of the regulation (49 CFR 573.4(c)(3, 4)).; We cannot agree, however, with your remaining assertions o non-compliance with the Regulations. While the Volkswagen Information Report is lacking in detail and is a poor example of an informational communication, it does contain minimal responses to the enumerated requirements of the Regulations.; Thank you for your interest in motor vehicle safety. Sincerely, Lawrence R. Schneider, Chief Counsel

ID: aiam1470

Dear Mr. Goichman: This responds to your March 26, 1974, request for information on sea belt regulations as they concern reclining passenger seats.; Federal Motor Vehicle Safety Standard No. 208, *Occupant Cras Protection,* requires passenger cars to be equipped with seat belt assemblies, but it does not contain performance requirements to regulate the effectiveness of the belt assembly with the seating system in the reclining position.; Federal Motor Vehicle Safety Standard No. 207, *Seating Systems* specifies minimum safety requirements for motor vehicle seats. The requirements of the standard are based on conventional seat designs that normally incorporate a seat back angle of approximately 25 degrees rearward inclination from the vertical. Standard No. 207 requires that reclining seats be tested in their most upright position and does not require seats to be tested in the reclining position.; The National Traffic and Motor Vehicle Safety Act of 1966 preempt state motor vehicle safety regulations which are not identical to the Federal standards with regard to the same aspect of performance and therefore any state law would be identical to Standards Nos. 207 and 208 on these aspects of performance (15 U.S.C. S 1392 (d)).; The engineering staff is not aware of any studies in the area of sea belts and reclining seats.; Yours truly, Richard B. Dyson, Assistant Chief Counsel

ID: aiam3139

Dear Mr. Keshav: This is in reply to your letter of September 2, 1979, to Franci Armstrong asking for an interpretation of Federal Motor Vehicle Safety Standard No. 108. SAE Standard J588e August 1970 is the referenced standard for turn signal lamps. Paragraph 4.2 of J588e requires that as mounted on the vehicle 'The optical axis (filament center) of the front turn signal lamp shall be at least 4 inches from the inside diameter of the retaining ring of the headlamp unit providing the lower beam'. You mentioned that on some motorcycles sold in the United States this requirement is satisfied only with the handlebar in the straight ahead position but not when turned to the full lock position. You asked whether this complies with Standard No. 108.; Table IV specifies that the minimum edge to edge separation between th headlamp and turn signal lamp on motorcycles is 4 inches. Most manufacturers have interpreted this requirement to mean that the separation is permanent, and have supplied turn signals that are mounted stationary with the headlamp, and that turn with it so that the separation distance is maintained. Therefore, the configuration you describe would not comply with Standard No. 108 because Federal requirements for location and mounting of lighting equipment are intended to apply to a vehicle under all its operating conditions.; Sincerely, Frank Berndt, Chief Counsel

ID: aiam0147

Dear Mr. Prahst: Thank you for your letter of February 24, 1969, to the Office o Standards Preparation, concerning the proposed lighting equipment on your dump trailers.; The lamps and reflectors shown on your drawing 701B1907 dated Februar 20, 1969, appear to be in conformance with the requirements of Standard No. 108 with the following exceptions:; >>>1. The required license plate lamp is not shown. 2. The minimum mounting height for reflectors is 15 inches. 3. With respect to maximum mounting zones for lamps and reflectors, th limiting dimensions of 16, 30, and 24 inches indicated on your drawing appear to be too liberal for a trailer with essentially square corners.; 4. With reference to Notes 2 and 3 on your drawing, certai restrictions as specified in paragraph S3.3 of Standard No. 108 are applicable for combination lamps.<<<; With respect to the requirements of Standard No. 108, I must point ou that this Bureau does not issue approvals on items of lighting equipment or on vehicle designs incorporating this equipment. Therefore, the above comments are for your information only, and in no way relieve the vehicle manufacturer from his responsibility for certifying that the assembled vehicle meets the requirements of Standard No. 108.; Sincerely, Charles A. Baker, Office of Standards on Accident Avoidance Motor Vehicle Safety Performance Service;