ID: nht95-1.49

TYPE: INTERPRETATION-NHTSA

DATE: February 3, 1995

FROM: Philip R. Recht -- Chief Counsel, NHTSA

TO: Dimitrios Kallieris -- Associate Professor and Division Chief, Experimental and Forensic Biomechanics, Ruprecht-Karls-Universitat Heidelberg

TITLE: NONE

ATTACHMT: Attached to 9/16/94 letter from Dimitrios Kallieris to Director, Office of the Federal Register, National Archives and Records Administration (OCC 10354)

TEXT: Dear Dr. Kallieris:

This responds to your FAX to Dr. Rolf Eppinger of NHTSA, requesting an interpretation of the requirements specified in Standard No. 212, Windshield Mounting. The answers to your two questions are provided below.

Standard No. 212 sets different windshield retention requirements for a vehicle depending on whether it is equipped with passive or manual restraints. S5.1 of the standard provides that vehicles equipped with passive restraints must retain not less than 50 percent of the windshield periphery after crash testing. S5.2 of the standard provides that vehicles that are not equipped with passive restraints must retain not less than 75 percent of the windshield periphery.

You stated that you have conducted 30 m.p.h. crash tests of motor vehicles with freshly adhered windshields. In the test vehicle, two Hybrid III dummies were placed in the front driver and passenger positions. Each dummy was restrained "by a three-poin t belt and air bag."

Your first question asked whether the vehicle is subject to the requirements of S5.1 for "vehicles equipped with passive restraints," or S5.2 for "vehicles not equipped with passive restraints." The answer to your question depends on whether the restrain t system in the tested vehicle meets the definition of "passive restraint system" set forth in S4 of the standard. That term is defined as:

a system meeting the occupant crash protection requirements of S5. of Standard No. 208 by means that require no action by vehicle occupants.

Section S5 of Standard No. 208 sets occupant protection requirements that must be met in frontal, lateral and rollover crashes.

You did not provide much information about the vehicle in question. We assume it is a passenger car. Standard No. 208 (S4.1.4) requires the following of current production passenger cars:

(a) At each front outboard designated seating position, each vehicle must meet the standard's frontal crash protection requirements (S5.1) by means that require no action by vehicle occupants (e.g., by means of an air bag or automatic restraints); (b) at the front center designated seating position and at each rear seating position, have a type 1 (lap) or type 2 (lap/shoulder) belt assembly that meet specified requirements; and

(c) either meet the lateral and rollover crash protection requirements of Standard No. 208 by means that require no action by vehicle occupants, or at each front outboard designated seating position, have a type 1 or type 2 belt assembly that meets th e requirements of S5.1 with front test dummies restrained by the type 1 or type 2 assembly in addition to the means that require no action by the vehicle occupant.

We assume that the "three-point belt and air bag" to which you refer were installed in the front outboard seating positions pursuant to these occupant protection requirements of Standard No. 208. NHTSA's longstanding position is that a vehicle equipped with a type 2 belt assembly and an air bag in those seating positions is equipped with a "passive restraint system," and is thus subject to the requirement of S5.1 that 50 percent of the windshield periphery must be retained. (See, e.g., August 18, 1986 letter to Volvo, copy enclosed.) As discussed in the enclosed letter, one of the reasons the agency adopted the 50 percent retention requirement for passive restraint-equipped vehicles was because there could be contact between an air bag system and the windshield, and incidental contact between an air bag-restrained test dummy and the windshield.

The Standard No. 208 requirements listed above mean that a vehicle with passive restraints must meet the Standard No. 208 performance criteria using only the passive restraints (air bag or automatic seat belt), and using both the passive and manual restr aints. This would also be the case for Standard No. 212. The windshield retention would have to be at least 50 percent with the dummies restrained by only the passive restraint, and with the dummies restrained by both the passive and manual restraints. Therefore, your test (which appeared to have been conducted using both the air bag and the type 2 belt assembly) may not have been the worst case situation.

Your second question asked whether the windshield displacements described in S5.1 and S5.2 are measured dynamically (i.e., during the crash), or statically (i.e., after the crash). NHTSA determines the portion of the windshield periphery that is retaine d by the vehicle after the dynamic crash test specified in the standard.

I hope this information is helpful. If there are any further questions, please contact Dorothy Nakama of my staff at this address or at (202) 366-2992. Our FAX no. is (202) 366-3820.

Sincerely

ID: 1983-3.15

TYPE: INTERPRETATION-NHTSA

DATE: 10/27/83

FROM: AUTHOR UNAVAILABLE; Frank Berndt; NHTSA

TO: State Purchasing and General Services Commission; Texas

TITLE: FMVSS INTERPRETATION

TEXT:

Mr. Troy C. Martin Specifications Chief State Purchasing and General Services Commission Lyndon Baines Johnson State Office Building P.O. Box 13047 Capitol Station Austin, Texas 78711-3047

Dear Mr. Martin:

This responds to your letter to Mr. Kratzke of my staff seeking an interpretation of Standard No. 222, School Bus Passenger Seating and Crash Protection (49 CFR S 571.222). You indicated that you have been informed that section S5.1.2 of that standard requires that 90 percent of the total projected area of the seat backs on school buses must lie between a horizontal plane passing through the seating reference point and a parallel horizontal plane 20 inches above the seating reference point, and that this requirement appeared to be a geometric impossibility. The information you received about the requirements of section S5.1.2 is erroneous.

Section S5.1.2 does not specify any requirements for the total projected area of the seat back. It simply mandates that the projected area of the seat back between the two planes you described be at least 90 percent of the width of the seat multiplied by 20. This requirement is very simple to satisfy geometrically by using a rectangle. If the seat back were rectangular, the area between the two planes would be 100 percent of the width of the seat multiplied by 20. The agency allows the width of the seat back to be multiplied by 90 percent so as to permit the use of seat backs which taper up at the top, but which still provide an adequate level of safety protection for the occupants.

The reason for specifying a requirement for the amount of area a seat back must have between these two planes is to ensure that "compartmentalization" is not compromised. Compartmentalization is the term for protecting the occupants in the event of a crash by confining them within an area of sturdy, well-padded seats. If the seat back in front of a school bus occupant occupied less than 90 percent of the area between the two planes (the area that occupant is most likely to contact in case of a crash), the padded area to cushion the blow of that occupant might not be sufficient.

If you have any further questions or need further information on this subject, please feel free to contact Steve Kratzke at this address and at (202) 426-2992.

Sincerely,

Frank Berndt Chief Counsel

August 11, 1983

Mr. Steve Kratzke, Attorney Office of Chief Counsel National Highway Traffic Safety Administration 400 7th Street SW, Room 5219 Washington, DC 20590

Dear Mr. Kratzke:

As you requested during our recent telephone conversation, I am asking for an interpretation of Paragraph S5.1.2. of Federal Motor Vehicle Safety Standard No. 222, "School Bus Seating and Crash Protection." I understand that the value

90% X Seat Width X 20

to be the projected area in square inches of the seat back (in a vertical plane) that lies between two horizontal planes, one going through the seating reference point (SRP), and the other through a point 20 inches above the SRP.

I have been informed by one of the engineers at a school bus body plant that 90% of the total projected area of the seat back must lie within these two planes. It appears to me that this is a geometric impossibility!

Your consideration of this request would be appreciated.

Sincerely yours,

Troy C. Martin Specifications Chief

TCM/dh

ID: nht74-3.11

DATE: 06/28/74

FROM: AUTHOR UNAVAILABLE; Lawrence R. Schneider; NHTSA

TO: Volkswagen of America, Inc.

COPYEE: ING. Hans-Jurgen Sassor -- AUDI NSU Auto Union Germany

TITLE: FMVSS INTERPRETATION

TEXT: This responds to your May 22, 1974, question whether Volkswagen's passive belt system may be equipped with a "comfort clip," and whether an optional Type I lap belt may be offered in conjunction with the passive system. Your passive system consists of an upper torso restraint and, in place of a lap belt, knee padding under the dashboard.

A vehicle which satisfies Standard No. 208, Occupant crash protection, may be equipped, at the option of the manufacturer, with additional safety belts which conform to Standard No. 209, Seat belt assemblies. Additional belts, like any required belt, must conform to the S7.2 requirements for latch mechanisms.

S7.2 Latch mechanism. A seat belt assembly installed in a passenger car shall have a latch mechanism --

(a) Whose components are accessible to a seated occupant in both the stowed and operational positions;

(b) That releases both the upper torso restraint and the lap belt simultaneously, if the assembly has a lap belt and an upper torso restraint that require unlatching for release of the occupant; and

(c) That releases at a single point by a push-button action.

This requirement assures that the occupant crash protection provided under Standard No. 208 is not diminished by a complicated and slow series of belt latch mechanisms which could otherwise be introduced into the vehicle.

Volkswagens' passive upper torso restraint and a separate active lap belt do not violate S7.2(b) in combination. Simultaneous release is required only "if the assembly has a lap belt and an upper torso restraint that require unlatching for release of the occupant." As described, Volkswagen's upper torso restraint does not require unlatching for release of the occupant.

With regard to our regulation of "comfort clips", we approved the use of a clip in a March 9, 1973, letter to General Motors, to relieve belt tension in limited circumstances. A copy of that letter is enclosed. In that case, the lap belt provided could be independently and firmly adjusted to limit occupant movement, providing protection in the event of lateral and rollover crashes. Until we have further details on the functioning of the Volkswagen clips, however, which we urge you to submit, we are unable to determine whether it would conform to the adjustment requirements of S7.1.1 of Standard No. 208, Occupant crash protection.

May 22, 1974

Lawrence R. Schneider Chief Counsel National Highway Traffic Safety Administration

Subject: MVSS 208, Occupant Protection - Request for Clarification

With the publication of Docket 74-4, Notice 2 (39 FR 14593), Volkswagen believes that MVSS 208 now adequately addresses the basic requirements covering passive belt systems, such as the Volkswagen passive shoulder belt/knee bolster restraint described in our petition of October 1, 1973.

However, in the final development phase of our passive belt system the possible inclusion of two ancillary devices came under consideration:

(1) the addition of an active lap belt,

(2) the addition of a "comfort clip" to the passive shoulder belt to relieve the belt force against the occupant during non-impact conditions.

Volkswagen respectfully requests NHTSA clarification of the current Federal requirements covering each of these items, which are discussed in more detail below.

1. Additional Active Lap Belt

Here we are interested in the requirements for the installation of active lap belts together with passive restraints, where the requirements of MVSS 208 are met by the passive restraints alone.

To our knowledge, the last published NHTSA statement addressing this matter appeared in 35 FR 16928 (Preamble to Docket 69-7, Notice 7): "Under the standard as adopted manufacturers will be free to supply seat belts as optional or standard equipment, but may not use them to satisfy the requirements of the standard. Standard No. 210 will continue to require seat belt anchorages to be installed by manufacturers, so that persons who wish to have seat belts installed in their vehicles, for their own use or for use with child seating systems, will be able to do so."

Specifically, we would like to know if a Type 1 lap belt (conforming to MVSS 209) can be installed in addition to the Volkswagen passive shoulder belt/knee bolster system, under either of the following circumstances:

a) where a vehicle equipped with the passive belt system alone meets the requirements of S4.1.2.2 and S4.5.3 of MVSS 208 (second option for passenger cars manufactured from Sept. 1, 1973 to the time when this option expires);

b) where a vehicle equipped with the passive belt system alone meets the requirements of S4.1.3 (a) through (d) (1) proposed in Docket 74-14, Notice 1, and S4.5.3 of MVSS 208.

Our main area of concern in this matter is in regard to the latch mechanism. The passive shoulder belt would have a latch mechanism conforming to S7.2 of MVSS 208, as required under S4.5.3.3(a). If the active lap belt is not governed by MVSS 208, the application of S7.2(b) of MVSS 208 for simultaneous release of lap and upper torso restraint is questionable.

2. Addition of "Comfort Clip"

We are aware that certain vehicles equipped with upper torso restraints with emergency-locking retractors incorporate belt force relief devices ("comfort clips") to make wearing of the belt more comfortable. Although the specifications governing these devices have not been incorporated into the Safety Standards, we understand that correspondence between individual manufacturers and the NHTSA has addressed the guidelines for their use. Since such a "comfort clip" could be applied to the VW passive belt, NHTSA clarification of the regulations relating to this specific usage is requested.

Your early attention to these inquiries would be greatly appreciated, in view of the lead-time constraints we would be facing for possible incorporation of the described items in 1975 model vehicles.

J. W. Kennebeck

Manager

Emissions, Safety & Development

ID: aiam1189

Dear Mr. Brown: This is in reply to your letter of June 21, 1973, requestin clarification of provisions of Motor Vehicle Safety Standard No. 217 dealing with the identification of emergency exits (S5.1.1). You ask whether this paragraph requires in the case of a 66-passenger school bus having a rear emergency exit which is not located in an occupant space, 66 separate labels, assumedly one for each designated seating position. You ask clarification as well for the identification requirements for emergency exits in a 44-passenger bus with one emergency exit in the rear, three push-out windows on one side of the bus, and two on the other, and with each of the five windows contained wholly in one occupant space. You appear to construe S5.5.1 to require a label for the occupant space of each designated seating position in the bus where a release mechanism is not present.; Your interpretation of the standard is not correct, and th requirements do not call for the extensive labeling you suggest. Paragraph S5.5.1 (second sentence) calls only for the placement of a label in occupant space of an *adjacent seat*, when that occupant space does not contain a release mechanism. Adjacent seats are defined in paragraph S4. of the standard as only those designated seating positions within a specified distance from an emergency exit. Thus, a label is required only when the occupant space of a passenger seat does not contain an emergency exit release mechanism and that seat is an adjacent seat as defined in the standard.; In the case of the school bus you describe, there do not appear to b any adjacent seats, and accordingly no emergency exit identification labeling is required in any occupant space. The only labeling required by S5.5.1 would be that required to appear at the exit itself. The same result would appear to be true with respect to the side push-out windows of the 44-passenger bus you describe if the release mechanism for each push-out window is within the occupant space of the adjacent seat. As you did not indicate the configuration of the seating positions at the rear of this bus we cannot provide you an opinion on the identification requirements at that location.; Yours truly, Richard B. Dyson, Assistant Chief Counsel

ID: nht87-1.51

TYPE: INTERPRETATION-NHTSA

DATE: 03/20/87

FROM: AUTHOR UNAVAILABLE; Erika Z. Jones; NHTSA

TO: M.B. Mathieson -- Direcdtor of Engineering, Thomas Built Buses, L.P.

TITLE: FMVSS INTERPRETATION

TEXT:

Mr. M.B. Mathieson Director of Engineering Thomas Built Buses, L.P. P.O. Box 2450 High Point, NC 27261

This is in reply to your letters to Francis Armstrong, Robert Williams, and Taylor Vinson, all of this agency. I regret the delay in this reply.

In summary, Thomas wishes to mount a body of its construction to a "General Motors chassis model #G31303, certified by G.M. to have a 10,000 lbs. maximum GVWR." Two prototypes have been operating. In testing for compliance with the frontal impact require ments of Standard No. 301, the rate of fuel leakage from a pinched or broken fuel line greatly exceeded the amount permitted by the standard. The test conducted by Thomas used sandbags to simulate occupant loading, and the impact velocity was reported to be 30.4 m.p.h. You have asked the following four questions:

"1. Does the result of the frontal barrier crash test with the discovered fuel leak constitute a safety defect?"

"2. Does the result of the frontal barrier crash test with the discovered fuel leak constitute an apparent or alleged noncompliance with FMVSS 301 requirement?"

The results of the frontal barrier crash test do not constitute an alleged or apparent noncompliance with Standard No. 301 as the impact velocity exceeded the 30 m.p.h. maximum test requirement. In addition, the vehicle's test weight in your test exceede d the test weight specified in S7.1.6(b) of the standard. Further, those results do not constitute a safety related defect regardless of the use of the vehicle. For NHTSA to find a safety related defect at 30.4 m.p.h. would be the equivalent of imposing a new standard without following Administrative Procedure Act requirements for rulemaking.

However, in our view, Thomas could not in good faith certify compliance of the completed bus with the 30 m.p.h. requirements if there was a failure when a correctly loaded bus was tested at 30.4 m.p.h and no counterbalancing data showing passes in other tests. Had NHTSA conducted a test at 30.4 m.p.h. and found a failure, it would have proceeded to conduct another test in accordance with the specifications of Standard No. 301 and test at a speed slightly less than 30 m.p.h. and with a Part 572 dummy in the driver's seat.

3. "What is NHTSA's interpretation of the correct vehicle test weight for FMVSS 301 certification testing of school buses and non school buses for vehicles in the under and up to 10,000 lbs.' class and equipped with seat belts required to comply with FMV SS 208?"

The test weight is set forth in paragraph S7.1.6(b) of Standard No. 301. That section provides that a "bus with a GVWR of 10,000 pounds or less is loaded to its unloaded vehicle weight, plus the necessary test dummies as specified in S6., plus 300 pounds or its rated cargo load and luggage capacity weight, whichever is less,...."

4. "If Thomas Built Buses performs a certification test to the requirements of FMVSS 301 with a similar vehicle (equipped with required seat belts which are required to comply with FMVSS 208) at a test weight as noted by GM (approximately 7,500 pounds) a nd the results show full compliance, what is the legal status or implication of completing and offering for sale this type of vehicle at a GVWR of up to 10,000 lbs. and indicating that it complies with FMVSS 301 on the basis of a successful test at the l ower GVWR."

This question cannot be answered because the facts stated in your question appear to be incorrect. Our review of the documentation you enclosed shows that GM has rated the incomplete vehicle at 10,000 pounds GVWR, rather than at approximately 7,500 pound s GVWR, as stated in your letter. GM has, however, specified the maximum unloaded vehicle weight as 6866 pounds, and stated that the completed vehicle will comply if its unloaded vehicle weight does not exceed this amount. It has also stated that the max imum unloaded vehicle weight plus 634 pounds (which, when added to 6866 pounds equals 7500 pounds) cannot exceed the vehicle's GVWR, which is 10,000 pounds in this case. GM therefore has made no representation that its incomplete vehicle will meet Standa rd No. 301 at weights outside those values, and the burden of certification falls upon the final stage manufacturer who completes the vehicle in a manner outside the limits cited by GM.

I hope that this answers your questions.

Sincerely,

Erika Z. Jones Chief Counsel

June 11, 1986

NATIONAL HIGHWAY TRAFFIC SAFETY ADMINISTRATION 400 7th Street, S.W. Washington,D.C. 20590

Attn: Mr. Francis Armstrong, Director Office of Vehicle Safety Compliance

Attn: Mr. Taylor Vinson, Office of Chief Counsel

Attn: Mr. Robert Williams, Office of Vehicle Safety Standards

RE: FMVSS 301 Fuel System Integrity

Gentlemen,

This letter is in reference to telephone conversations of June 9, 1986, with Mr. Martin Paliokas, Mr. Bob Krause, and Mr. Robert Williams regarding a possible safety defect, and/or a possible non-compliance with FMVSS 301. This instance involves a Thomas Minotour Model school bus, in the "10,000 lbs. or under" class GVWR.

Thomas Built Buses, L.P. proposes to mount the body of this model school bus on a General Motors chassis model #G31303, certified by G.M. to have a 10,000 lbs. maximum GVWR, and has, in fact, had two prototype vehicles operating in public service for som e time.

Pursuant to FMVSS 222, para. S5(b), Requirements, each of these vehicles is equipped with seat belts at each designated seating position, that meet the applicable requirements of 571.208 and 571.209, etc., as specified in para. S5(b).

Due to some proposed body structural changes, Thomas Buses elected to perform durability testing and barrier crash tests on the final configuration of the proposed vehicle. After completion of the durability testing, which comprises 4,000 miles of operat ion over a prescribed test track program at Transportation Research Center in East Liberty,Ohio, the vehicle was completely inspected, including the chassis. No deterioration or distress of any nature was found. The vehicle was then transferred to the fa cilities of Arvin/Calspan Advanced Technology Center in Buffalo, N.Y. for barrier crash testing.

For purposes of continuity and repeatability Thomas elected to use the barrier crash requirements as specified in FMVSS 301 for this portion of our test program. To determine the vehicle loaded condition to be used for the lateral moving barrier crash an d the frontal barrier crash, we noted the following requirement of FMVSS 301.

Para.S6.1 Frontal Barrier Crash:

When the vehicle, traveling longitudinally forward at any speed up to and including 30 mph impacts......with 50th percentile test dummies as specified in Part 572 of this chapter at each front outboard designated seating position and at any other positio n whose protection system is required to be tested by a dummy under the provisions of Standard 208 .... ..fuel spillage shall not exceed the limits of S5.5.

Para. -S6.3 Lateral Moving Barrier Crash:

When the vehicle is impacted on either side....with 50th percentile test dummies as specified in Part 572 of this chapter at positions required for testing to standard No. 208...... fuel spillage shall not exceed the limits of S5.5.

Thomas Built Buses interpreted the above requirements of FMVSS 301 as intending to require that testing of school buses "at or under" 10,000 lbs. GVWR be performed at a GVWR approximating the loaded passenger weight, as is required for school buses with GVWR in excess of 10,000 lbs. (Specified in FMVSS 301, para. S7.1.6(c).) Accordingly, since our design passenger weight for this vehicle would bring the GVWR very close to 10,000 lbs. maximum GVWR, Thomas elected to test the vehicle loaded with sand bags to simulate the final vehicle configuration with a full passenger load.

On May 28, 1986, Arvin/Calspan performed the lateral moving barrier crash per the requirements of FMVSS 301 with the vehicle at approximately 10,000 lbs. GVWR. The vehicle was again completely inspected. Other than minor sheet metal deformation in the ar ea of the fuel tank filler neck no damage was noted to body or chassis. The test successfully demonstrated compliance with FMVSS 301 to this point. (Static rollover testing was not done.)

On May 29, 1986, Arvin/Calspan performed the frontal barrier crash per the requirements of FMVSS 301. Impact velocity was reported to be 30.4 miles per hour. A significant amount of crushing was experienced at the front of the vehicle in the cab/engine a rea. Inspection revealed that just beside and behind the right front wheel the chassis frame rail had distorted severely, pinching or breaking one or more fuel lines that are tied to the frame rail in the G.M. "as delivered" configuration. Rate of leakag e from this fuel line significantly exceeded the limits of FMVSS 301, para. S5.5 and appeared to be siphoning fuel from the main tank which was positioned higher than the fuel line break. The leak was stopped by pinching the line between the tank and the leak area.

Upon contacting G.M. personnel regarding the results of our testing, we were directed by them to the Incomplete vehicle document statements regarding their certification limitations. As we understand this document, even though the chassis is certified as being able to be completed as a school bus with a 10,000 lbs. GVWR, the G.M. certification testing to FMVSS 301 requirements was limited to a GVWR of approximately 7,500 lbs., which is apparently G.M.'s understanding of the FMVSS 301 requirements.

The following items are enclosed for your assistance in under standing our questions in this matter:

a) The G.M. document for Incomplete Vehicle.

b) Pictures of the vehicle before and after frontal barrier crash testing to show the area of concern.

Thomas Built Buses, L.P. respectfully submits the following questions:

1. Does the result of the frontal barrier crash test with the discovered fuel leak constitute a safety defect?

2. Does the result of the frontal barrier crash test with the discovered fuel leak constitute an apparent or alleged non-compliance with FMVSS 301 requirement?

3. What is NHTSA's interpretation of the correct vehicle GVWR for FMVSS 301 certification testing of school buses and non-school buses for vehicles in the "under and up to 10,000 lbs." class and equipped with seat belts required to comply with FMVSS 208?

4. If Thomas Built Buses performs a certification test to the requirements of FMVSS 301 with a similar vehicle (equipped with required seat belts which are required to comply with FMVSS 208) at a GVWR as noted by G.M. (approximately 7,500 lbs.) and the r esults show full compliance, what is the legal status or implication of completing and offering for sale this type of vehicle at a GVWR of up to 10,000 lbs. and indicating that it complies with FMVSS 301 on the basis of a successful test at the lower GVW R?

Thomas Built Buses has presently stopped all further work on the development of this model. In expectation of a successful test program, considerable amount of money has been spent on tooling, prototype parts, etc. Anything that could be done to expedite answers to the above questions would be most helpful in our determination of further action. Thank you.

Sincerely yours,

THOMAS BUILT BUSES, L.P. M. B. MATHIESON, Director of Engineering

ID: aiam3948

Dear Mr. Mizuguchi: Your letter of February 28, 1985, was forwarded to my office for reply You asked whether the webbing attached to a buckle you intend to use must meet the webbing width requirement of S4.2 of Standard No. 209, *Seat Belt Assemblies*. The webbing is enclosed in a plastic sheath. As explained below, the webbing must meet the width requirement of the standard.; S4.2 of Standard No. 209 provides that the 'width of the webbing in seat belt assembly shall be not less than 1.8 inches, except for portions that do not touch a 95th percentile adult male with the seat in any adjustment position and the seat back in the manufacturer's nominal design riding position when measured under the conditions prescribed in S5.1(a).' The purpose of S4.2 is to ensure that belt webbing which comes into contact with an occupant has a minimum width that spreads the load imposed by the belt in a crash. By requiring webbing to spread rather than concentrate the load, the belt width requirement helps minimize the possibility of webbing-caused injury.; In the case of your design, the webbing is enclosed in tightly-fitting plastic sheath. You state that the webbing/sheath combination can come into contact with an occupant. The sheath enclosed with your sample is made from an easily deformable plastic. Thus, when the crash loads are imposed by the belt, the sheath will deform and the crucial factor in concentrating the load on an occupant is the width of the belt. Since the webbing/sheath combination can contact and impose crash loads on an occupant, the agency concludes that the webbing must meet the minimum width requirement of S4.2.; If the webbing were encased in a reinforced sheath that did no appreciably deform under loading, the agency would consider both the width of the webbing and its encasing sheath in determining whether the requirement of S4.2 was met.; I have enclosed the sample of your product sent with your letter. I you have any further questions, please let me know.; Sincerely, Jeffrey R. Miller, Chief Counsel

ID: nht73-3.45

DATE: 03/23/73

FROM: AUTHOR UNAVAILABLE; R. B. Dyson; NHTSA

TO: Seminole Trailer Manufacturing Corp.

TITLE: FMVSS INTERPRETATION

TEXT: This is in reply to your letter of March 6, 1973 to this agency asking whether it is permissible under Standard No. 108 to locate boat trailer identification lamps on the first crossmember forward of the rearmost crossmember. You believe that the identification lamps will have a longer life span in this location.

The general locational requirement that a lamp be "on the front" or "on the rear" was never intended to specify that it be at the extreme front or rear of a vehicle. Clearance and identification lamps required to be "on the front" are generally mounted on a truck cab or body, for instance. Therefore your proposed location is acceptable to meet the requirements of Table II of the Standard. However, identification lamps, wherever located, must meet the visibility requirements of paragraph S4.3.1.1, and if they do not meet them in your proposed location the trailer will not comply with Standard No. 108.

ID: nht90-3.92

TYPE: Interpretation-NHTSA

DATE: September 10, 1990

FROM: Paul Jackson Rice -- Chief Counsel, NHTSA

TO: David G. Dick Acts Testing Labs, Inc.

TITLE: None

ATTACHMT: Attached to letter dated 2-20-90 from D.G. Dick to NHTSA (OCC 4452)

TEXT:

This responds to your letter asking about the head impact protection requirements set forth in paragraph S5.2.3.2(a) of Standard 213, Child restraint systems. I regret the delay in responding.

Paragraph S5.2.3.2(a) states that certain energy absorbing material used to cover child seat surfaces must have a 25 percent compression-deflection resistance of not less than 0.5 and not more than 10 pounds per square inch (psi). You ask whether a valu e slightly less than 0.5 (such as the 0.47 psi example you provided) would be rounded to 0.5 psi. If rounding were permitted, you point out that the rounded value would meet the 0.5 psi requirement of S5.2.3.2(a).

The answer to your question is no, NHTSA would not round the value to 0.5 psi when testing the child seat. Rounding is generally not used in the safety standards. The standards expressly specify when rounding is appropriate. Standard 222, School bus p assenger seating and crash protection, specifies that the number of seating positions in a school bus bench seat (S4.1) is determined by rounding. In view of the express reference to rounding in some safety standards, and since S5.2.3.2(a) does not expr essly state rounding is appropriate, the value for the compression-deflection resistance would not be rounded.

You also ask whether there is any situation in which a value of less than 0.5 psi would be acceptable. The answer is "no." The minimum of 0.5 psi is required by S5.2.3.2(a) for restraints (other than a harness) recommended for children weighing less th an 20 pounds. Any value less than the minimum required value is a noncompliance.

Your last question asks about the reasons for the 0.5 psi minimum. In the agency's notice adopting the compression-deflection requirements, the agency indicated that those requirements would allow the use of a wide range of materials which should enable manufacturers to provide protective padding without cost increases. A copy of that notice is enclosed for your information.

I hope this information is helpful. Please contact us if you have further questions.

ID: 08-001245 belly pad

ID: nht74-2.27

DATE: 06/12/74

FROM: AUTHOR UNAVAILABLE; R. B. Dyson; NHTSA

TO: Truck Trailer Manufacturers Association

TITLE: FMVSS INTERPRETATION

TEXT: This is in response to your letter of May 29, 1974, concerning paragraph S5.3.2 of Federal Motor Vehicle Safety Standard No. 121, Air brake systems.

When a full trailer is tested for compliance with S5.3.2, the wheels on the steerable axle(s) cannot lock up at speeds above 10 mph except for controlled lockup of wheels allowed by an antilock system.

Yours truly,

ATTACH.

Truck Trailer Manufacturers Association

May 29, 1974

Larry Schneider -- Chief Counsel, National Highway Traffic Safety Administration

Subject: FMVSS-121 - Request for Interpretation

Dear Mr. Schneider:

A number of our members are currently involved in the redesign of braking systems in order to comply with the regulations specified by FMVSS.121. In this regard, we would appreciate your advice on the following:

Section S5.3.2 specifies antiwheel lockup control on all wheels except "lockup of wheels on non-steerable axles other than the two rearmost non-liftable, non-steerable axles on a trailer with more than two non-steerable axles."

Does this imply that all steerable axles must have antilock control?

Sincerely yours,

Burt Weller -- Engineering Manager