National Highway Traffic Safety Administration (NHTSA), Department of Transportation.
Denial of petition for a defect investigation.
This notice sets forth the reasons for the denial of a petition submitted to NHTSA under 49 U.S.C. 30162, requesting that the agency investigate an alleged safety-related defect in certain Ford Escort and Mercury Tracer vehicles. The petition is hereinafter identified as DP01-001.Start Further Info
FOR FURTHER INFORMATION CONTACT:
Peter C. Ong, Office of Defects Investigation, NHTSA, 400 Seventh Street, SW, Washington, D.C. 20590. Telephone: (202) 366-0583.End Further Info End Preamble Start Supplemental Information
Mr. Randy D. Brantley (petitioner) submitted a petition to NHTSA by letter dated February 13, 2001, requesting that a safety-related defect investigation be initiated with respect to the non-deployment of the frontal air bags in frontal crashes in model years (MY) 1998 through 1999 Ford Escort and Mercury Tracer passenger vehicles. Specifically, the petitioner alleges that he had noticed in NHTSA's consumer complaint database that there were many reports of both driver and passenger side air bags not deploying upon impact. Since both the MY 1998 and 1999 Ford Escort and Mercury Tracer have the same frontal passive restraint system, they are treated as the subject vehicles in this analysis.
The frontal air bag supplemental restraint system, when used with safety belts, is part of the vehicle's frontal occupant protection system that includes the vehicle's structural crumble zone, interior structure design/padding, instrument panel (IP) padding, and the energy absorbing steering wheel. As a supplemental restraint system, the air bag restraints reduce the risk of severe injuries and fatalities in frontal impacts. The air bags are designed to deploy and inflate in impacts that generate sufficient longitudinal deceleration to potentially cause moderate to serious injury to the vehicle's front seat occupants. Frontal air bags are not designed to deploy in side, rear, or rollover crashes or in frontal impacts that generate low longitudinal deceleration (such as low speed impacts and “soft” impacts that result in sheet metal deformation as opposed to major chassis/structural damage).
Manufacturers set deployment thresholds to enhance protection of the frontal occupants in severe frontal collisions such that the deployment of the air bags would help reduce the risk of serious injury or fatality. Likewise, the threshold is designed to prevent deployment in less severe collisions where air bag deployment is not likely to provide substantial benefits. The risk of injury during air bag deployment, particularly with respect to unbelted or out-of-position occupants, also provides a sound basis for setting the threshold to prevent deployment in less severe collisions. Manufacturers may select the deployment threshold that they believe is the most appropriate.
Real-world collisions often involve offset impacts, oblique angle impacts, override or underride impacts. These different impacts may or may not generate sufficient force and deceleration along the front to rear axis of the vehicle or apply significant force to the frame, suspension and engine to initiate air bag inflation. This can lead consumers to expect that the air bag should deploy in certain crashes resulting in significant body damage to the vehicle when in fact the crash force along the front to rear axis of the vehicle was not sufficient to deploy the air bags. The misconceptions about the criteria for deployment have caused allegations of non-deployment to be the most common type of air bag-related complaint reported to NHTSA.
When reviewing allegations of improper air bag non-deployment, NHTSA investigators analyze (1) The extent of vehicle frontal damage through pictures, repair invoices, and/or police accident reports, (2) the medical records to ascertain type and severity of personal injury, and (3) technical information that may indicate systematic or component related defect trends that lead to the non-deployment of the air bags.
A review of the agency's data files, including information reported to the DOT Auto Safety Hotline, shows 72 complaints of non-deployment in the subject vehicles. Thirty-nine of these complaints alleged injuries due to the non-deployment. (In the manufacturer's database, only 44 of the 278 owner reports/crash claims/litigation cases alleged injury associated with air bag non-deployments.) NHTSA attempted to contact all of the 39 complainants who alleged injury, plus some of the more recent complainants who did not specify any injury, to request additional crash and/or injury information. The follow-up contacts provided additional crash and injury information from 34 complainants.
NHTSA reviewed its crash reports and Ford's information, including crash damage, vehicle crash dynamics, and injury severity, and did not find any trend or pattern of air bags in the subject vehicles failing to deploy in crashes when they should have deployed. The crashes were minor in nature and many of them were underride impacts into the rear of pickup trucks, which typically result in major deformation of the vehicle's hood and upper regions of the fenders that absorbs much of the crash energy. It should be noted that a complaint often alleges an impact speed higher than what the damage indicates, since pre-impact braking will often slow the vehicle down dramatically prior to impact, and a driver will often not have any reliable way to estimate the actual impact speed.
Furthermore, NHTSA's analysis of the injuries experienced by the occupants of the subject vehicles does not suggest that deployment of the air bags in the subject vehicles in these crashes would have provided significant benefit. The injuries were minor in nature. All but one were AIS-1 (Abbreviated Injury Scale) severity injuries, with one AIS-2 severity injury (broken nose).
NHTSA reviewed Ford's developmental tests on air bag deployments and found that the frontal air bags in the subject vehicles deploy at an impact velocity comparable to other passenger vehicles. Ford reports that the air bag system in the subject vehicles are designed not to deploy when a vehicle is operated on rough roads and not to deploy under “soft” impacts that damage sheet metal but do Start Printed Page 55243not impact hard points on the vehicle such as the frame, suspension, and engine. Many of the “underride” crashes that ODI reviewed fall into this “soft” impact category, and air bag deployment was not appropriate under the circumstances.
For the foregoing reasons, and in view of the need to allocate and prioritize NHTSA's limited resources to best accomplish the agency's safety mission, the petition for a defect investigation is denied.Start Signature
Issued on: October 25, 2001.
Kenneth N. Weinstein,
Associate Administrator for Safety Assurance.
[FR Doc. 01-27405 Filed 10-31-01; 8:45 am]
BILLING CODE 4910-59-P