[Federal Register Volume 59, Number 145 (Friday, July 29, 1994)]
[Unknown Section]
[Page 0]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 94-18515]


[[Page Unknown]]

[Federal Register: July 29, 1994]


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DEPARTMENT OF TRANSPORTATION
 

Denial of Petition

    This notice sets forth the reasons for the denial of a petition 
submitted to the National Highway Traffic Safety Administration (NHTSA) 
under 49 U.S.C. Sec. 30162 (formerly Section 124) of the National 
Traffic and Motor Vehicle Safety Act of 1966, as amended.
    In a letter dated March 14, 1994, Dennis and Sharyn A. McLain 
petitioned NHTSA to ``initiate a defect investigation into and recall 
all Chevrolet Blazers, and other vehicles, with fuel systems that do 
not possess mechanisms to prevent the escape or continued supply of 
fuel in the event of a crash.'' As evidence of the alleged defect, the 
petition cites a March 20, 1992, accident that resulted in fatal 
injuries to Kristin Dawn McLain Sutherland. In the accident, Ms. 
Sutherland's vehicle, a General Motors Corporation (GM) small-size (S/
T) utility vehicle with a fuel injected engine (``subject vehicle''), 
was involved in a severe frontal crash. After a second impact, a fire 
started in the engine compartment of the Blazer, a 1987 model equipped 
with a throttle body injected 2.8 liter V-6 engine. The fire spread to 
the occupant compartment, contributing to Ms. Sutherland's injuries. 
The letter also alleges additional defects in the fuel system of the 
Blazer, related to the potential for fuel leakage or fire after a front 
impact collision.
    Regarding the issue of electric fuel pump control after collision 
impact, there are two general approaches used by motor vehicle 
manufacturers to stop the flow of unwanted fuel from the fuel pump. The 
most common approach is based upon detection of engine stoppage. When 
the fuel pump control logic receives a signal that the engine has 
stopped running, power to the tank-mounted electric fuel pump is shut 
off. This method produces a result similar to that seen in carbureted 
vehicles using mechanical fuel pumps, which were typically driven by 
the engine camshaft. An alternate approach is based upon detection of 
impact severity. This method uses an electro-mechanical inertia switch 
in the fuel pump circuitry. If the switch detects a significant 
collision impact, the switch will break the electrical circuit to the 
fuel pump and remain open until it is manually reset. Ford is the only 
major manufacturer that has adopted the impact detection approach in 
vehicles sold for use in the United States.
    GM uses a variation of the engine stoppage approach, supplying 
power to the fuel pump only when the ignition switch is ``on'' and the 
engine control module is receiving reference pulses from the 
distributor or the oil pressure switch is closed, both of which 
indicate the engine is operating. Thus, contrary to the petitioners' 
allegation, the GM fuel system design does include a ``mechanism to 
prevent the escape or continued supply of fuel in the event of a 
crash.''
    The petition asserts two general deficiencies in the design of the 
fuel system in the subject vehicles: (1) that absent a mechanism to 
prevent such occurrence, the fuel pump will continue operating after 
the system has been damaged in a collision; and (2) that additional 
defects in the system design and construction render it prone to suffer 
such damage in a frontal impact collision.
    To evaluate whether the subject vehicles demonstrate an inordinate 
rate of fuel leaks and fires in frontal impacts, the Office of Defects 
Investigation (ODI) analyzed data from various accident reporting 
systems. ODI compared the post-collision fuel leakage and fire 
experience of the subject vehicles, and other GM vehicles using fuel 
injection and electric fuel pumps, with that of peer populations, 
including Ford vehicles using an inertia switch.
    Data from NHTSA's Fatal Accident Reporting System (FARS) was 
analyzed to assess vehicle fire experience in severe accidents, 
involving one or more fatalities. The data were analyzed to determine 
the incidence of fire among vehicles involved in fatal accidents. 
Additional analyses were performed using Michigan State accident 
records. The Michigan records are compiled from all accidents where a 
police report is filed and, thus, include the full range of crash 
severities as compared to fatal-only crashes in FARS. Michigan's 
database also includes an indication of fuel leakage (with or without 
fire) as an added element for comparative analysis. A third reporting 
system, the National Accident Sampling System, was used as a general 
index of the comparative fire experience between GM and Ford vehicles 
that were involved in crashes that required subsequent towing.
    ODI's analysis considered accident data for the general case (all 
impact modes) and for the frontal and side crashes, separately. In each 
case, ODI's analysis found no statistically significant difference in 
the rate of fuel leakage and/or fire between the subject vehicles and 
peer populations of small-size utility vehicles, including Ford's 
Bronco II. Additional analyses comparing the experience of GM passenger 
cars with those of Ford and other manufacturers produced similar 
results. In some of the comparisons, GM vehicles exhibited a slightly 
higher likelihood of fire or fuel leakage than the Ford vehicles. In 
other peer comparisons, the relationship was reversed. However, in no 
case was there a difference between GM and Ford that was statistically 
significant. Finally, a comparison of the subject vehicles (with fuel 
injection) with carbureted S/T utility vehicles, equipped with 
mechanical fuel pumps, did not show a significant difference in the 
rate of fuel leakage events in frontal impact collisions.
    In summary, the GM fuel system design does include a mechanism 
intended to address the concerns expressed in the petition regarding 
post-collision fuel pump control. GM's approach to this problem is 
similar to that employed by most other manufacturers. In addition, ODI 
has received no other complaints regarding any of the defects alleged 
by the petitioners in the fuel system of the subject vehicles. Most 
importantly, a comprehensive analysis of real-world crash data does not 
indicate that the subject vehicle, or vehicles equipped with a similar 
fuel delivery system, exhibit higher fuel leakage and/or fire rates in 
crashes when compared to other vehicles.
    In consideration of the available information, NHTSA has concluded 
that there is not a reasonable possibility that an order concerning the 
notification and remedy of a safety-related defect in relation to the 
petitioners' allegations would be issued at the conclusion of an 
investigation. Since no evidence of a safety-related defect trend was 
discovered, further commitment of resources to determine whether such a 
trend may exist does not appear to be warranted. Therefore, the 
petition is denied.

    Authority: 49 U.S.C. Sec. 30162; delegations of authority at 49 
CFR 1.50 and 501.8.

    Issued on: July 26, 1994.
William A. Boehly,
Associate Administrator for Enforcement.
[FR Doc. 94-18515 Filed 7-28-94; 8:45 am]
BILLING CODE 4910-59-M