ID: nht78-3.1

DATE: 04/27/78

FROM: AUTHOR UNAVAILABLE; J. J. Levin, Jr.; NHTSA

TO: Bureau of Transportation - L.A., CA

TITLE: FMVSS INTERPRETATION

TEXT: This responds to your March 10, 1978, question whether Standard No. 121, Air Brake Systems, applies to a device that automatically applies to vehicle's service brakes when a sensing bumper mounted at the rear of the vehicle is tripped by contact with an object during a backing maneuver. For purposes of your question, I assume that the vehicle, whether new or used, has been certified to comply with Standard No. 121 prior to installation of the device.

The answer to your question is no. Paragraph S3 (Applicability) of Standard No. 121 states that the standard applies to trucks, buses, and trailers equipped with air brake systems (with some specified exceptions). The standard therefore applies only to vehicles, and does not apply to motor vehicle equipment such as the braking actuator you describe. The vehicle must, of course, conform to Standard No. 121 following installation of the device, if the installation occurs prior to the first purchase in good faith for purposes other than resale.

After the first retail sale, $ S 108(a)(2)(A) of the National Traffic and Motor Vehicle Safety Act (the Act) (15 U.S.C. $ S 1397(a)(2)(A)) prohibits, with one exception, manufacturers, distributors, dealers, and repair businesses from knowingly rendering inoperative devices or elements of design installed in satisfaction on a safety standard such as Standard No. 121.

ID: nht78-3.10

DATE: 09/22/78

FROM: AUTHOR UNAVAILABLE; J. J. Levin, Jr.; NHTSA

TO: Mercedes-Benz of North America, Inc.

TITLE: FMVSS INTERPRETATION

TEXT: This responds to your recent question whether Mercedes may use a dynamic test to evaluate seat structure integrity instead of the static test specified in the testing procedures of Safety Standard No. 207.

The answer to your question is yes. A manufacturer is permitted to use whatever test procedures or methods of evaluation he chooses to assure its vehicles are in compliance with Federal motor vehicle safety standards. The legal requirement under the National Traffic and Motor Vehicle Safety Act (15 U.S.C. 1391, et seq.) is that the manufacturer exercise due care to determine that his vehicles will be in compliance with all applicable standards when tested by the agency in accordance with the test procedures specified in those standards.

Therefore, you may use a dynamic test method to determine the integrity of your vehicle seats if this constitutes the exercise of due care to assure the seats meet the performance requirements specified in Standard No. 207. Of course, it cannot be determined whether a manufacturer in fact exercised due care in advance of the actual events leading to the certification of compliance. Likewise, the agency will not approve a manufacturer's method of testing in advance of certification.

Please contact me if you have any further questions.

SINCERELY,

MERCEDES - BENZ OF NORTH AMERICA, INC.

July 3, 1978

National Highway Traffic Safety Administration

Attention: Office of Chief Counsel

Subject: Request for Interpretation; FMVSS 207

Dear Madam or Sir,

Federal Motor Vehicle Safety Standard No. 207 specifies in Section S5. Test Procedures, loading techniques to evaluate seat structure integrity. All figures in this standard depict draw bars or other force controlling devices typical of static testing procedures.

Mercedes-Benz of North America believes that such a description of these tests restricts a manufacturer from using alternative test procedures. It is also believed that dynamic testing techniques are more realistic and within the intent of this standard when they produce forces equal to or exceeding those specified in this standard. We would appreciate receiving your confirmation of this opinion at your earliest convenience to enable the use of a dynamic test as an alternative to the current technique specified.

HEINZ W. GERTH

ID: nht78-3.11

DATE: 10/06/78

FROM: AUTHOR UNAVAILABLE; J. J. Levin, Jr.; NHTSA

TO: Southwest Research Institute

TITLE: FMVSS INTERPRETATION

TEXT: This responds to your June 27, 1978, letter concerning the requirements of Safety Standard No. 207 as they would apply to pedestal seat assemblies for use in van vehicles. You ask whether your test methodology is consistent with the requirements of the standard and whether the pedestal base is considered part of the seat assembly.

As you know, the agency does not approve a manufacturer's test methods. A manufacturer must exercise due care to ascertain that his product is in compliance with all applicable motor vehicle safety standards and regulations. While your test methods appear to be reasonable, the agency will test seats in the vehicle rather than on a surrogate test frame. You must exercise due care to assure that your simulated test is a true determination whether the seats would comply with the standard when tested as provided in that standard. (The vehicle manufacturer is, of course, responsible for compliance with Standard 207.)

Regarding your second question, the pedestal base would be considered part of the seat assembly for purposes of Standard 207. This means that the agency would test the entire assembly by applying a force of 20 times the combined weight of the seat and the pedestal, contrary to your simulated test procedure of using only the weight of the seat frame and adjuster, without the pedestal base attached.

Finally, the force requirements of Safety Standard No. 210, Seat Belt Assembly Anchorages, (5,000 pounds) are applied simultaneously with the force requirements in Standard No. 207, if the anchorages are connected to the vehicle seat, to the pedestal, or to the pedestal base.

Please contact this office if you have any further questions, and please excuse the delay in this response.

SINCERELY,

SOUTHWEST RESEARCH INSTITUTE

DEPARTMENT OF STRUCTURAL SYSTEMS AND FIRE TECHNOLOGY

June 27, 1978

National Highway Traffic Safety Administration Office of Chief Counsel

Attention: Chief Counsel

Subject: Interpretation of FMVSS 207/210 Load Application to Van Seating Assemblies Gentlemen:

SwRI is currently performing qualification testing of van seating systems for commercial seat assembly manufacturers. The purpose of these tests has been to provide test data which demonstrates that the seat assembly appears to qualify to the requirements of FMVSS 207. These seat assemblies consist of a seat frame, seat adjuster tracks (if applicable), and pedestal base. Since this entire assembly is manufactured as a separate component for sale to van manufacturers, SwRI performs the tests and reports the results with the understanding that the portion of the assembly above the pedestal base does/does not appear to qualify to the load/time profile requirements of the Standard. In addition, SwRI insures that the test conditions which are not consistent with the requirements of FMVSS 207 are delineated, which are:

1. The assembly is tested on a rigid test frame (not in a vehicle).

2. SwRI utilizes available fasteners to secure the pedestal base to the test fixture (since OEM fasteners are not available).

3. Satisfactory test results are reported which indicate that only the seat structure and fasteners attaching the seat frame to the adjuster track and pedestal base appear to qualify to the requirements of FMVSS 207.

4. The fore/aft CG loads are calculated based on the seat frame and adjuster weight without the pedestal base attached.

SwRI would like an interpretation to determine if this methodology is consistent with the requirements of FMVSS 207.

SwRI has recently received a "barrel" van seat assembly which is constructed as illustrated in the attached sketch. This assembly has seat belt anchorage holes in the gussetted plate. The seat frame is attached to the gussetted plate which is secured to the pedestal base. SwRI would like an interpretation on the correct load application to this assembly by responding to the following:

* Is the load applied as required in FMVSS 207 -- i.e. Forward CG load = 20 x seat assembly weight + 2500 lbs. for each anchorage?

or

* Is the FMVSS 210 load (5000 lbs.) applied separately?

It appears the key question with these seat assemblies is, "Is the pedestal base considered a part of the seat assembly as it applies to the FMVSS 207 requirements?"

Your prompt response to this request will be appreciated as SwRI has a sponsor awaiting test results.

Charles J. Kerr Research Engineer

cc: VINCE QUARLES SEAT STRUCTURE TUBING

FIBERBOARD

PEDESTAL BASE

PEDESTAL ANCHORAGE POINTS

GUSSETTED PLATE

SEAT BELT ANCHORAGE POINTS

"BARREL" VAN SEAT ASSEMBLY

(Graphics omitted)

ID: nht78-3.12

DATE: 07/20/78

FROM: AUTHOR UNAVAILABLE; M. M. Finkelstein; NHTSA

TO: Hon. John Glenn -- U.S. Senate

TITLE: FMVSS INTERPRETATION

TEXT: This is in response to your letter of June 7, 1978, pertaining to your constituent's, Mrs. Carl A. Koch, concerns regarding motor vehicle seat backs that do not permanently lock.

Federal Motor Vehicle Safety Standard No. 207, Seating Systems, copy enclosed, requires that hinged or folding occupant seat or occupant seat back shall be equipped with a self-locking device for restraining the hinged or folding seat or seat back and a control for releasing that restraining device. The industry is currently installing two types of seat back latches, a manual conventional type of latch and a new inertial locking device. The standard requires that the locks withstand a load 20 times the weight of the hinged portion of the seat and is not required to withstand the load of an occupant striking the seat back. Rear occupants are expected to be restrained by the rear seat belts, however, seat backs in locked position, because of some padding, do provide some protection for unrestrained occupants.

The seat back latch referred to by your constituent is an inertial seat back latch which is neither required nor prohibited by the standard. The industry, in an effort to facilitate rapid egress from a motor vehicle in emergency situations, such as a fuel fire, have introduced inertial seat back latches. The seat back latch will lock when the low forces of a panic breaking situation occurs or a high impact force occurs, releasing itself automatically when the inertial forces drop to a predetermined force, normally approximately .5g, allowing rapid occupant egress.

We believe there can be positive post-crash escape advantages for the inertial type seat back latches, however, it would appear from Mrs. Koch's experience that it may be warranted to initiate an investigation of the type of inertial latches installed in the 1978 Ford Granada. Accordingly, I am forwarding a copy of your letter to our Office of Defects Investigation for their action to determine if and what corrective action may be warranted.

I hope this information is helpful to you in responding to Mrs. Koch's inquiry. If I can be of further assistance, please let me know.

SINCERELY,

Michael M. Finkelstein Acting Associte Administrator for Rulemaking

June 2, 1978

Dear Senator Glenn,

I have no idea who to write to about what I consider a major problem and since your name and address was listed in the paper and I voted for you I am asking you to get my complaint to the right person.

I recently purchased a 1978 Ford Granada, two door car. No one told me that the seats now do not lock permanently in place and must be released. A small truck with no stop lights on back caused me to brake real fast and my eight year old was sitting on the end of the back seat and the seat acted as a slide when it fell forward and propelled my daughter right up into the windshield. I took it to the service department and have even written Ford Motor Company and they tell me that they cannot lock this seat for me as Ralph Nader has made them put in this kind of seat. They further told me that until I have an accident and maybe kill one of my little ones by having them fly out the windshield they have no way of proving wether my seats actually lock on rapid decellaration. There could be a malfunction and they have no way of checking it out. I can't believe that if you could fly in outer space there isn't something that could be done to give you a choice of wether we want our seats locked while we are driving or wether we prefer them to be movable. If no one is in the car and you stop fast the seat flies forward. It is a distraction and safety hazard. When a child is old enough to open a seat belt it is impossible to keep him in them if he wants to be able to see out the side or front window. I bought a two door car because I have eight children from twenty six to six and I want them confined while I am driving where if anything happens they will receive the least injury possible. With locked seats and no doors to open or windows to open the child is farely safe and I have never had a scare like the incedent that I related at the beginning of my letter.

I am sorry but I think Ralph Nader has made a big goof and who ever in government that is responsible for helping him make this change in automobiles better take a second look and do some more testing. I feel the manufacturer should also be required to have some way of testing to make sure that if I have an accident that these seats are going to lock as we are told they will. I have taken this car out in the country and slowed rapidly, stopped fast and done everything short of hitting a brick wall and these seats will not lock.

Thank you for getting my complaints to the right person,

Dolores A. Koch (Mrs. Carl)

ID: nht78-3.13

DATE: 02/13/78

FROM: AUTHOR UNAVAILABLE; E. T. Driver; NHTSA

TO: Emil M. Mrak

TITLE: FMVSS INTERPRETATION

TEXT: This is in reply to your letter of December 12, 1977, to Secretary of Transportation, Mr. Brock Adams, concerning the seat belts in your automobile.

Federal Motor Vehicle Safety Standard No. 208, Occupant Crash Protection, requires that the distance between the lap-shoulder belt intersection and the vertical centerline of a 50th percentile (164 pounds, 5 feet 8 inches) adult male occupant must be at least six inches when the seat is in its rearmost position. The purpose of this requirement is to reduce the risk of the occupant "submarining" out from under the belt and to reduce the possibility of the shoulder belt pulling the lap belt up onto the abdomen where it could cause serious injury in a crash.

The possibility of submarining increases as the intersection of the lap-shoulder belt is moved toward the occupant's center-line and/or as seat cushion rigidity is reduced. In other words, the closer the intersection of the lap-shoulder belt is to the centerline of the occupant, and the softer the seat, the more the danger of "submarining" in a crash. The standard does not limit the maximum distance from the occupant's centerline to the lap-shoulder belt intersection because of varying degrees of seat rigidity and installation configurations. Thus, contrary to what you may have been told, manufacturers who provide belt systems with distances greater than six inches do so by choice and not because they are required to do so by Federal standards.

Thank you for informing us of your problem.

SINCERELY,

December 12, 1977

The Honorable Brockman Adams The Secretary of Transportation

Dear Mr. Adams:

Sometime ago I wrote the Ford Company complaining about the inaccessibility of the short portion of the seat belt to a person who is up in years. I pointed out that because of the extreme difficulty of hitching these up, more and more people are failing to use seat belts. Furthermore, the twisting and squirming required could very well result in backbone injuries to elderly people.

I was astounded to receive a letter from the Ford Company indicating that the Federal Standards required such a belt. This is hard for me to believe. In any event, I would appreciate knowing if what they told me is the truth, and if it is, then, the truth, I would strongly recommend that this requirement be revised. If it is not a requirement, then I think the Ford Company should be told to take the blame off the Department of Transportation.

If Congressional help is needed to make such a change, I would be glad to pursue it.

I am enclosing copies of my letter to Mr. Wilson of the Ford Company and also his reply, which as indicated above, astonished me.

Emil M. Mrak

ENCLS.

December 12, 1977

A. S. Wilson Ford Parts and Service Division Ford Motor Company

Dear Mr. Wilson:

I am enclosing a copy of a letter I have written to the Secretary of Transportation, Brockman Adams, which is self-explanatory.

I feel so strongly in this matter that I would go to certain of my friends in Congress, if need be, and as much as I dislike most of the things that Nader does, I would even be willing to go to him.

Emil M. Mrak

ENC.

Ford Parts and Service Division Ford Motor Company

November 23, 1977

Emil M. Mrak

Dear Mr. Mrak:

We are sorry to learn of the problem you are experiencing using the seat belts in your Cougar Brougham. As you probably know, the Ford Motor Company has been an active proponent of the use of seat belt systems for many years. Ford does not have complete freedom, however, in selecting the design of the seat belt system since the Federal government does impose requirements that seat belt systems must meet. An explanation of certain of these requirements may be helpful in giving you a better understanding of why present seat belt systems are different than those you may have been accustomed to using.

For all passenger vehicles built after January 1, 1972, Federal safety standards require the installation of a three-point seat belt system; that is, a combination lap belt and shoulder harness. The Federal standard also requires that the intersection or attaching point of the shoulder harness to the lap belt be at least six inches from the centerline of an average size adult male. In the opinion of the Federal authorities, this intersection point offers the best protection to occupants using the shoulder harness. In order for Ford to satisfy this requirement, it is necessary to limit the length of the buckle portion of the lap belt.

It is clear from your letter that shortening the buckle portion of the lap belt has created a problem for some people. We regret the inconvenience but hope that it will not deter you from continuing to use the seat belt system when operating your vehicle.

We appreciate the interest you have shown in this matter and thank you for giving us the opportunity to respond to your questions.

A. S. Wilson Owner Relations

November 10, 1977

A. S. Wilson Ford Parts and Service Division Ford Motor Company

Dear Mr. Wilson:

In May I wrote to you concerning problems with my seat belts in the new Cougar Brougham we had just purchased. You replied on May 17 indicating that I should return to the selling dealer with the complaint.

First of all, I thought I made it clear in my letter that I was not complaining. I was asking for an improvement. In any event, I had the dealer refer to Ford Technical Service Bulletin 100, Article 1290, as indicated in your letter, and this advice was completely useless, and the dealer, as far as I'm concerned, was helpless.

The real problem with the seat belt is that the part attached to the seat is so short that a person of my age finds it literally impossible, or at least very difficult, to squirm around and get it attached.

I am taking the liberty of writing this second letter to you because I have read that fewer and fewer people are using seat belts. I am certain it is because of the fact that it is so difficult to use them. In order to use the belt I must squirm and fuss and work and finally I get it attached. Some day I may well injure a spinal disk.

I think this is a problem for the Ford engineers. When I wrote to you I was asking for an extension so it would be easier to attach them, but I did not get an iota of help from you.

I feel that if anyone not using the belt because of this difficulty should get into an accident and be injured, that person would have a case for suit against the Ford Company because of the inadequacy of the belt hook-ups.

I have felt like writing to the Transportation Department and also to Senator Eagleton, but since I am a stockholder in Ford, I thought I had better wait until I get another reply from you.

Emil M. Mrak

cc: BRUCE WILLIAMS

ID: nht78-3.14

DATE: 04/13/78

FROM: AUTHOR UNAVAILABLE; J. J. Levin, Jr.; NHTSA

TO: P. Arquin

TITLE: FMVSS INTERPRETATION

TEXT: This responds to your recent letter asking what loading conditions are applicable for purposes of measuring the wheelbase of passenger cars, under the new phased-in passive requirements of Standard No. 208, Occupant Crash Protection. Apparently, the wheelbase of one of Peugeot's vehicles having an independent rear suspension varies as a function of the vehicle loading.

The phased-in passive requirements of Standard No. 208 were based on a determination of the lead time necessary to engineer passive restraints into each size class of automobile. Wheelbase was chosen as a measure to delineate the phasing requirements because it is directly related to vehicle size and because it is a well-defined quantity that does not vary significantly within a given car line.

For purposes of measuring wheelbase, the vehicle is loaded according to the general test conditions of Standard No. 208. These test specifications, including loading, are meant to approximate the likely condition of the vehicle under normal driving circumstances. Since a vehicle having a variable wheelbase will generally carry the same weight as the average automobile of its size, it is appropriate that the wheelbase on such a vehicle be determined under the loading conditions specified under Standard No. 208. Therefore, Peugeot should measure the wheelbase of its vehicle under the loading conditions specified in paragraph S8.1.1(a) of the standard.

SINCERELY,

U.S. TECHNICAL RESEARCH COMPANY

February 8th, 1978

Joseph J. Levin Chief Counsel National Highway Traffic Safety Administration U.S. Department of Transportation

Re.: Wheelbase Cutoff Points for FMVSS-208 Application

Dear Mr. Levin:

Certain automobiles with independent rear suspensions have a wheelbase which varies as a function of the vehicle loading. In order to determine the effective date of FMVSS-208 for one of our vehicles, it is necessary for us to know under which loading conditions the wheelbase should be measured. "Curb Weight" as defined in CFR 49, Chapter V, Subchapter A, Part 571, Subpart A, R 571-2 and "Unloaded Vehicle Weight" as defined in 36 F.R. 2511 (Feb. 5, 1971) have been suggested by your staff as the most probable possibilities

We would appreciate receiving a prompt official clarification on this matter.

P. Arquin Government and Engineering Liaison

ID: nht78-3.15

DATE: 07/17/78

FROM: AUTHOR UNAVAILABLE; J. J. Levin, Jr.; NHTSA

TO: Automobile Importers of America

TITLE: FMVSS INTERPRETATION

TEXT: This responds to your recent letter asking whether passive safety belts are exempt from the requirements of Safety Standard No. 209, Seat Belt Assemblies.

The answer to your question is yes, with one exception. Paragraph S4.5.3.4 of Safety Standard No. 208, Occupant Crash Protection, specifies that passive safety belts that are not required for the vehicle to meet the perpendicular frontal crash protection requirements of the standard must meet the requirements of Standard No. 209. Therefore, only passive belts that are installed to meet the frontal crash protection requirements of Standard No. 208 are exempted from the requirements of Standard No. 209.

Sincerely,

June 8, 1978

Joseph Levin Chief Counsel National Highway Traffic Safety Administration

Dear Mr. Levin: Subject: Request for an Interpretation FMVSS 208/209

In reviewing the requirements presented in FMVSS 209, Seat Belt Assemblies in connection with the design of passive belt systems, there appears to be no distinction between the applicability of the standard as to active and passive belt systems. In reviewing FMVSS 208, Occupant Crash Protection however, paragraph 4.5.3.4 appears to exempt passive belt systems from compliance in any manner with the requirements of FMVSS 208. Since such an exemption would provide the design latitude necessary in the development of an optimum passive belt system, I would appreciate your confirmation that this exemption is intended.

In view of the extensive development efforts now underway in the engineering departments of many manufacturers, an expeditious response to this request would be appreciated.

George C. Nield President

ID: nht78-3.16

DATE: 11/09/78

FROM: AUTHOR UNAVAILABLE; Joan Claybrook; NHTSA

TO: Hon. Bob Wilson - H.O.R.

TITLE: FMVSS INTERPRETATION

TEXT: This is in response to your letter of October 17, 1978, concerning a telephone call from your constituent, Mr. Stefan Dagrowski, urging standardization of the type of release on seat belts.

Federal Motor Vehicle Safety Standard No. 208, Occupant Crash Protection, issued March 10, 1971 (36FR4600), required that effective January 1, 1972, passenger car seat belt assemblies would be released at a single point by push button action. To that extent, the type of release on seat belts is standardized since our standards are primarily performance oriented, and the manufacturers are free to design however they wish to meet those performance requirements.

I hope this information is sufficient to satisfy Mr. Dagrowski's interest in standardized seat belt releases.

SINCERELY,

Congress of the United States House of Representatives

October 17, 1978

Dear Ms. Claybrook:

I recently received a telephone call from a constituent, Mr. Stefan Dagrowski, urging standardization of the type of release on seat belts.

Your advice and counsel as to anything currently underway in this regard, which I can pass along to Mr. Dagrowski, will be greatly appreciated.

Thank you for your attention to this matter and kind regards.

Bob Wilson Member of Congress

Honorable Joan Claybrook National Highway Traffic Safety Administration

ID: nht78-3.17

DATE: 09/27/78

FROM: AUTHOR UNAVAILABLE; J. J. Levin, Jr.; NHTSA

TO: Wayne Corporation

TITLE: FMVSS INTERPRETATION

TEXT: This responds to your recent letter asking whether Safety Standard No. 208 applies to side-facing seats in multipurpose passenger vehicle vans. You also ask to be advised of the criteria to be used for the installation of seat belts in these vehicles.

Safety Standard No. 208, Occupant Crash Protection, does require side-facing seats in multipurpose passenger vehicles to comply with one of the options under paragraph S4.2.2, since the side-facing seats in question would be considered designated seating positions. If a manufacturer chooses to install seat belts under one of the options of that paragraph, the seat belt assemblies must comply with Safety Standard No. 209, Seat Belt Assemblies, and Safety Standard No. 210, Seat Belt Anchorages.

Safety Standard No. 210 does exempt side-facing seats from its strength requirements, but all other requirements of the standard would be applicable. However, we strongly recommend that belt anchorages for side-facing seats be of at least equivalent strength to anchorages for forward and rearward facing seats, since the strength specifications are only minimum performance requirements. Side-facing seats were excepted from the strength requirements specified in the standard because the forces acting on side-facing seats are different from those acting on forward or rearward facing seats and the requirements and procedures were specifically developed for these latter seats.

Please contact this office if you have any further questions.

SINCERELY,

Wayne Corporation

August 24, 1978

Office of Chief Counsel National Highway Traffic Safety Adm.

Gentlemen:

The Wayne Corporation manufacturers small buses (GVWR 10,000 lbs. and under), Busette and Transette, which have a normal passenger capacity of 16 to 20 passengers.

Some of these buses are equipped to accommodate transporting the handicapped. In some of these cases, the operators' requirements for lifts, wheelchair anchorage devices, side facing seats, etc., reduced the passenger capacity to less than 10 persons, in which case the vehicle becomes, for purpose of Federal Certification, a multipurpose passenger vehicle rather than a bus.

Which, if any, of the requirements of FMVSS 208, Passenger Crash Protection, apply to side facing seats installed in the MPV discussed above?

If you should find that S4.1.2.3 of FMVSS 208 applies at the option of the manufacturer, please advise the criteria to be used for the installation of the seat belts, taking into consideration that all current seat belt requirements relate only to forward and rearward facing seats.

Robert B. Kurre Director of Engineering

ID: nht78-3.18

DATE: 02/16/78

FROM: AUTHOR UNAVAILABLE; J. J. Levin, Jr.; NHTSA

TO: Volvo of America

TITLE: FMVSS INTERPRETATION

TEXT: This responds to your letter of December 20, 1977, enclosing a previous letter requesting an interpretation of paragraph S4.3(j) of Safety Standard No. 209, Seat Belt Assemblies. I am sorry that your earlier letter was misplaced.

Volvo is correct in its interpretation that the requirements for emergency locking retractors in S4.3(j)(2) and (3) were promulgated for reasons of comfort and convenience, although this in turn is directed toward a safety objective. As you know, the more comfortable and convenient belts are, the more likely they will be worn by motorists. Further, the requirements in these paragraphs assure that the driver can make necessary movements in the occupant compartment safely.

Paragraph S4.3(j)(2) specifies that an emergency locking retractor

"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."

Volvo interprets this to require that the retractor not lock before the webbing extends 2 inches when the webbing is subjected to an acceleration of 0.3g. This is incorrect. The requirement specifically states that the retractor is to be accelerated. The agency does not agree that keeping the belt stationary and accelerating the retractor is equivalent to keeping the retractor stationary and accelerating the belt. This is due to the fact that inertial forces react upon the retractor during its acceleration that are not present when the webbing alone is accelerated. Therefore, results from the two methods of testing could differ significantly.

I hope this has been responsive to your inquiry, and if we can be of any further assistance please let us know.

Sincerely,

ATTACH.

December 20, 1977

Hugh Oates -- Office of Chief Council, National Highway Traffic Safety Administration

Dear Mr. Oates:

As per our telephone conversation, enclosed is one copy of Volvo's Request for Interpretation FMVSS #209 dated April 4, 1977.

We are looking forward to your response to this request for interpretation.

If additional information is required on this subject, don't hesitate to contact the undersigned.

Sincerely yours, William Shapiro PE -- Regulatory Analysis Engineer

ENC.

April 4, 1977

Frank Berndt -- National Highway Traffic Safety Administration

Re: Request for Interpretation FMVSS #209

Dear Mr. Berndt,

Volvo requests interpretation of certain provisions in Section 4.3(j) of FMVSS #209.

S4.3 (j) Emergency-locking retractor

An emergency-locking retractor of a Type 1 or Type 2 seatbelt assembly, when tested in accordance with the procedures specified in paragraph S5.2(j) -

(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 15 degrees or less from its orientation in the vehicle.

It is our interpretation that the requirements in Section 4.3(j)(1) were promulgated for safety reasons, while the requirements in Section 4.3(j)(2) & (3) were promulgated for comfort requirements for webbing acceleration sensitive retractors and vehicle acceleration sensitive retractors respectively.

Because we believe that the requirements in Section 4.3 (j)(2) were promulgated to prevent premature locking of the retractor when the webbing is being withdrawn, we interpret this to require that the retractor shall not lock before the webbing extends 2 inches when the webbing is subjected to an acceleration of 0.3 g or less. Is this interpretation correct? Also, we would like to point out that in our opinion testing the emergency-locking retractor system in the following two manners gives the same results.

1) Keeping the belt stationary and accelerating the retractor and

2) Keeping the retractor stationary and accelerating the belt.

If there are any questions pertaining to this issue, please feel free to contact me at your convenience.

In advance, thank you for your attention to this matter.

Sincerely, William Shapiro, P.E. -- Regulatory Analysis Engineer