National Highway Traffic Safety Administration (NHTSA), Department of Transportation (DOT).
Receipt of petition.
Spartan Motors USA, Inc (Spartan), has determined that certain model year (MY) 2015-2019 Spartan Specialty MM and K2 motorhome chassis do not fully comply with Federal Motor Vehicle Safety Standard (FMVSS) No. 121,
The closing date for comments on the petition is June 12, 2019.
Interested persons are invited to submit written data, views, and arguments on this petition. Comments must refer to the docket number cited in the title of this notice and may be submitted by any of the following methods:
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• Comments may also be faxed to (202) 493-2251.
Comments must be written in the English language, and be no greater than 15 pages in length, although there is no limit to the length of necessary attachments to the comments. If comments are submitted in hard copy form, please ensure that two copies are provided. If you wish to receive confirmation that comments you have submitted by mail were received, please enclose a stamped, self-addressed postcard with the comments. Note that all comments received will be posted without change to
All comments and supporting materials received before the close of business on the closing date indicated above will be filed in the docket and will be considered. All comments and supporting materials received after the closing date will also be filed and will be considered to the fullest extent possible.
When the petition is granted or denied, notice of the decision will also be published in the
All comments, background documentation, and supporting materials submitted to the docket may be viewed by anyone at the address and times given above. The documents may also be viewed on the internet at
DOT's complete Privacy Act Statement is available for review in a
This notice of receipt of Spartan's petition is published under 49 U.S.C. 30118 and 30120 and does not represent any agency decision or other exercise of judgement concerning the merits of the petition.
In support of its petition, Spartan submitted the following reasoning:
1. Paragraph S5.1.2.1 of FMVSS No. 121, requires the combined volume of all service reservoirs and supply reservoirs to be at least 12 times the combined volume of all service brake chambers. The chassis affected by this condition are equipped with a T-24 brake chamber on the steer axle, T-30 brake chamber on the drive axle and T-16 brake chamber on the tag axle. In using the values in Table V of FMVSS No. 121, the cumulative air capacity of these brake chambers would be 404 cubic inches. Multiplying by 12, the needed air reservoir capacity would be 4,848 cubic inches. To better illustrate the issue, refer to the table below:
In paragraph S5.1.1 of FMVSS No. 121, the vehicle is to be equipped with an air compressor of sufficient capacity to increase air pressure in the supply and service reservoirs from 85 psi to 100 psi when the engine is operating at the vehicle manufacturer's maximum recommended revolutions per minute (r.p.m.) within a time, in seconds, determined by the quotient (actual reservoir capacity × 25)/required reservoir capacity). In using this equation, vehicles subject to the condition represented in the table above, the air pressure would be required to go from 85 psi to 100 psi within 24 seconds (4,674 * 25)/4,848). Using the same equation and the required air reservoir capacity of 4848 cubic inches, the air pressure would need to increase from 85 psi to 100 psi within 25 seconds. Vehicles subject to the condition that has resulted in the non-compliance to paragraph S5.1.2.1 could increase air pressure from 85 psi to 100 psi in less than 6 seconds, well within the requirement of 25 seconds. Further, vehicles subject to this condition have a cut in pressure set at, or greater than, the minimum requirement of 100 psi.
The impact of having 3.5 percent less air reservoir capacity than required, the difference in the cut in pressure requirement of only 1 second would appear to have an adverse consequence of a slight increase in air compressor cycling. However, this would be dependent on application of the service brakes.
Motorhomes have a similar duty cycle to that of a tractor-trailer where they are driven at highway speeds with infrequent brake applications during such drives. Motorhomes also are largely driven from owner residences to campground locations throughout the traveling season.
Given these brake applications would appear to be less frequent than those in stop and go applications. The lower than required capacity, with the one second difference time to increase air pressure, may not be noticeable by the driver and would not impact the braking performance of the vehicle.
2.
In conclusion, Spartan stated that the actual air reservoir capacity in the affected motorhome chassis may be 3.5 percent less (174 cubic inches) than the calculated required amount. However, due to the duty cycle of a motorhome and the air compressor cycling, that is well within the required time using the equation from FMVSS No. 121, Spartan believes the noncompliance is inconsequential as it relates to motor vehicle safety. The less than required capacity does not appear to impact vehicle braking performance (
NHTSA notes that the statutory provisions (49 U.S.C. 30118(d) and 30120(h)) that permit manufacturers to file petitions for a determination of inconsequentiality allow NHTSA to exempt manufacturers only from the duties found in sections 30118 and 30120, respectively, to notify owners, purchasers, and dealers of a defect or noncompliance and to remedy the defect or noncompliance. Therefore, this decision only applies to the subject vehicles that Spartan no longer controlled at the time it determined that the noncompliance existed. However, the granting of this petition does not relieve vehicle distributors and dealers of the prohibitions on the sale, offer for sale, or introduction or delivery for introduction into interstate commerce of the noncompliant vehicles under their control after Spartan notified them that the subject noncompliance existed.