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Interpretation ID: nht88-4.21

TYPE: INTERPRETATION-NHTSA

DATE: 11/30/88

FROM: R. H. MUNSON -- FORD MOTOR CO

TO: ERIKA Z. JONES -- CHIEF COUNSEL NATIONAL HIGHWAY TRAFFIC SAFETY ADMINISTRATION

TITLE: NONE

ATTACHMT: ATTACHED TO LETTER DATED 03/28/89 FROM ERIKA Z. JONES -- NHTSA TO ROBERT H. MUNSON, REDBOOK A33(4), STANDARD 208, STANDARD 209

TEXT: Dear Ms. Jones:

Request for Interpretation

Standards Nos. 208 and 209 contain apparently inconsistent provisions. For the reasons discussed below, Ford believes that the agency intended the later-promulgated provisions to limit the application of the earlier-promulgated ones, and therefore no co nflict actually exists between them. Ford respectfully asks you to confirm that its belief is correct.

In brief, S4.6.3 of Standard No. 208 exempts from the Standard No. 209 restrictions on elongation of seat belt webbing those Type 2 seat belt assemblies that are installed to comply with the manual restraint requirements (S4.1.2.3) of Standard No. 208 and are required by S4.6.1 or S4.6.2 of the standard to meet its frontal crash test requirements. S4.6(a) of Standard No. 209 repeats that exemption. In contrast, S4.5(b) of Standard No. 209 provides that a Type 2 seat belt assembly that "includes a l oad limiter n1 and that does not comply with the elongation requirements of this standard may be installed in a motor vehicle only in conjunction with an automatic restraint system as

part of a total occupant restraint system." (emphasis added). Despite this apparently inconsistent provision, the rulemaking history discussed below suggests strongly that the agency intended to permit such Type 2 seat belts to be used in manual restrai nt systems if such belts also have to meet the frontal crash test requirements of Standard No. 208.

n1 The agency defined "load-limiter" in the preamble to Docket No. 80-12, Notice 2 as a "seat belt assembly component or feature that controls tension on the seat belt and modulates or limits the force loads that are imparted to a restrained vehicle o ccupant by the belt assembly during a crash." (46 Fed. Reg. 2618, January 12, 1981). Notice 2 also added a similar definition to S3 of Standard No. 209.

Discussion

In a final rule n2 modifying Standards Nos. 208 and 209, the agency amended S4.6.2 of Standard No. 208 to require certain trucks and multipurpose passenger vehicles built on or after September 1, 1991, and equipped with a Type 2 seat belt assembly at a f ront outboard designated seating position pursuant to S4.1.2.3 of that standard to meet the frontal crash test requirements of S5.1. The agency also added S4.6.3, a provision that exempts Type 2 seat belt assemblies subject to the requirements of S4.6.1 or S4.6.2 from the webbing width, strength, and elongation requirements of Standard No. 209 [S4.2(a)-(c)] and from the requirements for assembly performance of that standard (S4.4). In addition, the agency amended S4.6 of Standard No. 209 to reiterate t hat exemption and require that such seat belt assemblies be specially labeled.

n2 Docket No. 74-14, Notice 53; 52 Fed. Reg. 44898, November 23, 1987.

In exempting dynamically-tested belts subject to S4.6.2 of Standard No. 208 from certain Standard No. 209 requirements, the agency stated in the preamble to Notice 53, under the heading "Revisions to Standard No. 209":

The agency noted that the webbing of automatic belts is currently excluded from the elongation and other belt webbing and attachment hardware requirements of Standard No. 209, since those belts have to meet the injury protection criteria of Standard N o. 208 during a crash. For dynamically-tested manual belts in passenger cars, NHTSA believed that an exclusion from the webbing width, strength and elongation requirements (sections 4.2(a)-(c) is also appropriate since these belts will also have to meet the injury protection requirements of Standard No. 208. The agency believes that for those same reasons, dynamically-tested safety belts in light trucks and multipurpose passenger vehicles should also be excluded from those requirements of Standard No. 20. (52 Fed. Reg. at 44906). n3

n3 The agency reiterated this reasoning in Docket No. 74-14, Notice 54 (53 Fed. Reg. 5579, February 25, 1988). This Notice denied petitions for reconsideration of the agency's decision to exempt dynamically-tested manual lap/shoulder belts from the a ssembly and elongation requirements (among others) of Standard No. 209. The Notice also denied a petition to delete the provision of Standard No. 208 which exempts automatic safety belts from the Standard No. 209 webbing requirements.

S4.5(b) of Standard No. 209, provides, however, that a Type 2 seat belt assembly that includes a load-limiter and that does not comply with the elongation requirements of Standard No. 209 may be installed in motor vehicles only in conjunction with an aut omatic restraint system as part of a total occupant restraint system. S4.5(c) of that standard also requires that any Type 2 seat belt assembly that includes a load-limiter and does not comply with these elongation requirements be marked or labeled with the following words:

This seat belt assembly may only be installed in vehicles in combination with an automatic restraint system such as an air cushion or an automatic belt. (emphasis added). n4

n4 S4.5 was promulgated in response to a Mercedes-Benz petition to allow use, in conjunction with air bag systems, of belts that did not meet the S4.2(c) elongation requirements. In the preamble to Docket No. 80-12, Notice 2, the agency explained tha t it had proposed restricting the use of load-limiting belts to vehicles equipped with automatic restraints because there are currently no dynamic performance requirements or injury criteria for manual belt systems used alone. There are no requirements to ensure that a load-limiting belt system would protect vehicle occupants from impacting the steering wheel, ins trument panel, and windshield, which would be very likely if the belts elongated beyond the limits specified in Standard No. 209. Therefore, the elongation requirements are necessary to ensure that manual belts used as the sole restraint system will ade quately restrain vehicle occupants. (46 Fed. Reg. 2618, 2619, January 12, 1981).

Ford believes that the more recently promulgated rule exempting manual Type 2 belt assemblies subject to S4.6.1 or S4.6.2 of Standard No. 208 from the elongation requirements of Standard No. 209 was meant to limit the restrictions of S4.5(b) of that stan dard to manual belt assemblies not required to undergo dynamic crash testing. Clearly, the agency's reasons for restricting use of the Type 2 seat belt assemblies specified in S4.5(b) to vehicles also equipped with automatic restraints do not apply to m anual Type 2 belts subject to the dynamic crash test requirements of Standard No. 208. Contrary to the preamble language quoted in footnote 4, those manual belts are subject to "dynamic performance requirements [and] injury criteria" meant to "ensure th at a load-limiting belt system would protect vehicle occupants . . ."

Hence, the elongation requirements are no longer "necessary to ensure that manual belts used as the sole restraint system will adequately restrain vehicle occupants." Indeed the agency expressly recognized this fact in the above-quoted excerpt from the p reamble of Docket No. 74-14, Notice 53, and also in Notice 54.

For the same reasons, Ford believes that manual Type 2 belts subject to S4.6 of Standard No. 208 are intended also to be exempt from the labeling requirements of S4.5(c) of Standard No. 209 and instead to be subject to the labeling requirements of S4.6(b ) of that standard.

Ford respectfully requests your concurrence in its interpretation. If, however, the agency believes that the apparent inconsistency can be cured only by amending Standards Nos. 208 and 209, Ford asks the agency to treat this letter as a petition for rul emaking.

Sincerely,