[Federal Register Volume 61, Number 235 (Thursday, December 5, 1996)]
[Notices]
[Pages 64563-64567]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 96-30773]


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DEPARTMENT OF TRANSPORTATION
National Highway Traffic Safety Administration


Denial of Motor Vehicle Defect Petition

    This notice sets forth the reasons for the denial of a petition 
submitted to NHTSA under 49 U.S.C. Sec. 30162 requesting that the 
agency commence a

[[Page 64564]]

proceeding to determine the existence of a defect related to motor 
vehicle safety.
    Ms. Joan Claybrook of Public Citizen submitted a petition dated 
June 4, 1996, requesting the agency to investigate more than 40 million 
model year (MY) 1978 through 1988 GM vehicles, equipped with the 
General Motors Corporation (GM) Type III door latch, to remedy an 
alleged safety-related defect in the door latch which reportedly fails 
to hold the door closed during a crash. Specifically, the petitioner 
alleges that during a collision, the Type III door latch allows the 
detent lever to be out of alignment with respect to the fork bolt. 
According to the petitioner, when this occurs, the fork bolt may be 
free to rotate and may disengage from the striker, allowing the door to 
inadvertently open and the occupants to be ejected.
    The petition was based on information from an Alabama product 
liability case Hardy v. General Motors Corporation, et al. (Circuit 
Court, Lowndes County, Alabama, Civil Action File No. CV9356), in which 
the plaintiff alleged that Mr. Hardy was ejected through an opened side 
door from a MY 1987 Chevrolet S-10 Blazer, equipped with the GM Type 
III door latch, and injured because the door latch failed to hold the 
door closed during a rollover accident.
    After reviewing the petition and its supporting materials, as well 
as information both furnished by GM and within the agency's possession 
from previous rulemakings and other actions, NHTSA has concluded that 
further investigation of the GM Type III side door latch is unlikely to 
result in a determination that the latch contains a safety-related 
defect and that a further commitment of agency resources in this effort 
is not warranted. The agency has accordingly denied the petition.
    NHTSA's Office of Defects Investigation (ODI) has prepared a report 
that describes in detail the agency's analysis of the allegation 
presented in the petition. Interested persons may obtain copies of that 
report by contacting the Technical Reference Division, NAD-52, Room 
5108B, 400 7th Street, SW, Washington, DC 20590, (202) 366-2768. A 
summary of this report is presented below.

System Description

    Front Door Latch and Lock Assembly. The side door latch assembly in 
these GM vehicles provides three major functions as described below.
    a. It provides a means of keeping the door closed.
    When closing the door, the latch fork bolt contacts the striker pin 
body. This causes the fork bolt to rotate in the latch and the 
``throat'' to wrap around the striker pin. A cam surface of the fork 
bolt causes the detent lever to ride on the cam until it drops into 
engagement with the secondary latch tooth of the fork bolt. Further 
inboard movement of the door causes the detent lever to ride on a 
second cam surface until it drops into engagement with the primary 
latch tooth of the fork bolt. A spring on the detent lever keeps the 
detent lever engaged with the fork bolt, keeping the door latched.
    b. It provides a means to unlatch the door from inside and outside 
the vehicle.
    To open the door, a release lever actuated by the door handle 
operates an intermittent lever that disengages the detent from the 
teeth of the fork bolt. When the outside handle is operated, a rod 
attached to the handle pushes the release lever in the latch, thereby 
disengaging the detent. When the inside handle is operated, a rod 
attached to the handle pulls a remote lever in the latch. This lever 
moves the release lever and also disengages the detent. When the detent 
is disengaged from the fork bolt, continuous outboard movement of the 
door causes the fork bolt to rotate until it clears the striker bolt.
    c. It provides a means to lock and unlock the door.
    To lock the door, a rod attached to the key cylinder mechanism or a 
rod attached to the inside locking button drives the locking lever in 
the latch to a locked position. The intermittent lever is thereby moved 
out of engagement with the detent lever and renders the door handles 
inoperative.

Modification

    The GM Type III door latch has two basic versions: one is the 
original design and the other is a modification of the same. The 
petitioner alleges that the original Type III side door latch is 
defective.
    The modification of the original latch involved the addition of a 
metal plate (support plate) within the latch assembly. This support 
plate was riveted in front of the fork bolt and detent lever and welded 
on the latch inboard edge. According to GM, the purpose of adding the 
support plate was to increase resistance to ``bypass,'' i.e., release 
of the latch due to mis-alignment of the fork bolt from the detent 
lever. The modification was first introduced as a running change on 
GM's K body passenger vehicles during MY 1986.

Vehicles Involved

    GM produced approximately 46 million MY 1978 through 1988 vehicles 
equipped with GM's ``original'' Type III and ``modified'' Type III door 
latches. Approximately 40 million of these vehicles were equipped with 
the GM's original Type III door latch that was built without a support 
plate. Beginning in MY 1986, the modified Type III door latch, which 
was built with a support plate, was used in certain models.

Owner Reports

    Analysis of the Office of Defects Investigation (ODI) computerized 
database for the subject vehicles revealed only one (1) complaint 
concerning side door opening during a collision accident. The vehicle 
involved was a MY 1984 Chevrolet Camaro that was built with the 
original Type III door latch. The report mentions that during the March 
13, 1996 accident, the side door was opened and the driver was injured 
but not ejected.

Testing

1. Static Test--Performed by NHTSA

    NHTSA's Office of Vehicle Safety Compliance (OVSC) has tested 
thirty-nine MY 1978-88 GM vehicles according to Federal Motor Vehicle 
Safety Standard (FMVSS) No. 206, ``Door locks and door retention 
components'' and all passed the requirements of the standard. The test 
vehicles were equipped with three different latches: twelve with the 
original Type III latch, eight with the modified Type III latch, and 
the remaining nineteen with a different (non-Type III) latch.
    Beginning with model year 1978, certain door latches that passed 
compliance testing to FMVSS 206 were further tested until failure to 
determine the ultimate load for each latch. The purpose was to gather 
additional information on the strength of the latches. Of the twenty 
compliance tests involving MY 1978-88 vehicles equipped with the Type 
III latches, ten were further tested until failure. The test-to-failure 
results showed that: (1) there was insignificant difference in strength 
between the original and modified Type III latches, and (2) both the 
original and modified Type III latches exceeded NHTSA's safety standard 
requirements, in many cases by a factor of two or more.
    In an effort to reduce the accident ejection rates on the nation's 
roadways, NHTSA has considered the possible benefits of upgrading FMVSS 
No. 206. In 1986, NHTSA initiated a pilot study and contracted with Chi 
Associates Inc. to correlate the ultimate strength (test-to-failure) of 
side door latches with the overall occupant ejection rates. In this

[[Page 64565]]

study, the ejection rate was determined, using the number of ejections 
in the Fatal Accident Reporting System (FARS) data divided by the 
number of vehicle registrations obtained from the POLK database for 173 
vehicles of various make and models. These vehicles were then divided 
and ranked into three groups with high, average, and low ejection 
rates. Eight vehicles from each of the high, average and low categories 
were selected for ultimate strength testing, with priority given to the 
major automobile manufacturers. All 24 vehicles tested were MY 1983 
models. The test results showed that GM's original Type III latch 
performed far better than many other latches. In fact, three of the 
four strongest tested latches in both longitudinal strength tests and 
transverse strength tests were original GM Type III latches.
    In 1988, as a follow-up study, NHTSA conducted its own door latch 
testing program at the Vehicle Research and Test Center (VRTC) to 
validate the findings of Chi Associates' study. A total of 25 latches 
were tested: two GM models with the original latch, two GM models with 
non-Type III Latches, and 21 non-GM latches. Each specimen was tested 
until failure, using a procedure similar to FMVSS No. 206, in order to 
determine its ultimate latch strength. The test results showed that in 
both the longitudinal and transverse loading directions, GM's original 
Type III latch was among the top six in terms of strength for the 25 
latches tested.
    In the mid-1980's, GM developed the Horizontal Rotation Test (HRT) 
as a way of simulating (and ultimately reducing the incidence of ) 
latch ``bypass,'' which can occur on all vehicles. In this test, the 
door latch and striker are allowed to rotate relative to one another to 
simulate rotation of the surrounding vehicle structure. GM provided 
NHTSA with information on the test fixture and some early test results. 
In 1991, NHTSA conducted an evaluation of GM's HRT on door latch 
integrity to determine if that test is a suitable replacement of or 
supplement to the FMVSS No. 206 test requirements. NHTSA analyzed the 
National Accident Sampling System (NASS) data and found that a GM's HRT 
would represent approximately 16 percent of the door opening cases that 
involve B pillar twisting.
    To further evaluate the HRT fixture, NHTSA conducted tests on door 
latches from thirteen MY 1981 and 1983 non-GM vehicles and from the MY 
1983 Buick Regal using GM's original Type III latch. For each latch-
type, two latches were tested to failure. To evaluate repeatability, 
five additional latches were selected from each previously tested 
vehicle group; a total of 25 additional latches were tested. The 
failure loads were correlated with ejection rates for the vehicles 
under consideration. The test results showed that the GM Type III latch 
was the strongest tested; the average strength of the seven tests of 
the original GM Type III latch was well above the breaking load of all 
non-GM latches.
    In January 1994, NHTSA conducted an additional follow-up study of 
the potential for different door latch failure modes. The following 
test-to-failure tests were conducted:
    a. Five MY 1989 non-GM vehicles and one MY 1993 non-GM vehicle were 
tested to failure, using a procedure similar to one specified in FMVSS 
No. 206. The test results were compared with those for the MY 1983 GM 
vehicles with the original Type III latch. Even against the newer non-
GM models, the original GM Type III latch compared favorably, at or 
above the median of all tests.
    b. Full-door longitudinal strength tests (latch strength tests with 
each latch mounted on a full door instead of on a test fixture) were 
conducted on 21 non-GM doors and two doors from GM models having the 
original Type III door latch. The full-door transverse strength test 
was performed on 15 non-GM doors and one door from a GM model using the 
original Type III door latch. In the full-door longitudinal strength 
test, the 1983 Buick Regal's original Type III latch outperformed all 
but two of the non-GM designs. In the full-door transverse strength 
test, the Buick Regal's original Type III latch outperformed all but 
one non-GM latch.
    c. The HRT was performed on six non-GM vehicles. The test results 
were compared with the average of the seven tests previously reported 
for the original Type III latch. Once again, the GM Type III latch from 
a 1983 model car compared favorably to all the newer vehicles tested by 
NHTSA.
    Static Test--Conducted by GM:
    GM's September 5, 1996 response to ODI's DP96-008 information 
request indicated that GM had tested twenty-four original Type III 
latches to the requirements of FMVSS No. 206--all passed.
    2. Dynamic Tests--Performed by NHTSA:
    FMVSS No. 208, ``Occupant crash protection''. NHTSA's OVSC tested 
two subject vehicles equipped with the original Type III latches and 
one subject vehicle equipped with a modified Type III latch. A review 
of the photographs in the three test reports revealed that no side door 
was opened on any of the test vehicles as a result of the 30 mph rigid 
barrier frontal crash.
    FMVSS No. 301, ``Fuel system integrity'' (Rear impact): NHTSA 
tested 20 vehicles equipped with the GM original Type III latch, and 
one subject vehicle equipped with the modified latch. A review of the 
photographs in the 21 test reports revealed that no side door opened on 
any of the test vehicles as a result of the 30 mph rear impact by a 
4,000 moving barrier.
    New Car Assessment Program. NHTSA tested 31 subject vehicles 
equipped with the original Type III latch, four subject vehicles 
equipped with the modified Type III latch, and five subject vehicles 
equipped with either the original or modified Type III latch (in 
certain model and model year vehicles both the original and modified 
Type III latches were used). Despite the severity of the 35 mph rigid 
barrier crash, a review of the photographs in the test reports revealed 
that no side door opened as a result of the crash.

2. Dynamic Tests--Performed by GM

    In its September 5, 1996 response to ODI, GM provided 42 crash test 
reports on vehicles equipped with Type III latches. These crash tests 
involved both developmental (non-production) vehicles and production 
vehicles, and were performed for a variety of evaluation purposes. Of 
the 38 developmental test vehicles, 28 were equipped with the original 
Type III latch, seven were equipped with the modified Type III latch, 
and three were equipped with unspecified Type III latches. Of the four 
production vehicles tested, three were equipped with the original Type 
III latch and one was equipped with the modified Type III latch.
    A total of 28 developmental vehicles equipped with the Type III 
door latch reportedly experienced side door openings during crash 
testing; 22 were equipped with the original Type III latch, four were 
equipped with the modified Type III latch, and two were equipped with 
either the original or the modified Type III latch. There was only one 
production vehicle which reportedly experienced side door opening--a MY 
86 Oldsmobile `H' body vehicle equipped with the original Type III 
latch. During the 50 mph high speed impact, the passenger side rear 
door latch separated from the striker, allowing the door to open.
    The rear door on a second production vehicle, a MY 1978 Chevrolet 
`T' body vehicle equipped with the original Type III latch, came 
partially unlatched during a 31 mph rear impact test.

[[Page 64566]]

    It is important to note that many of these crash tests involved 
prototype or altered Type III latches and vehicles and thus cannot be 
considered equivalent to tests involving standard Type III latches and 
production vehicles. Prototype or altered latches involved 
significantly different weld patterns, bolt structures, materials, and 
varying striker and detent sizes. These developmental modifications may 
significantly change the Type III latch's strength, and there is no 
record that any of these developmental modifications (with the 
exception of the support plate) survived into the final design. 
Similarly, the vehicles used in developmental tests were often two or 
more years ahead of their production date. These differences mean that 
the prototype Type III door latches or vehicles used in developmental 
crashes are not necessarily representative of production versions, and 
thus doors opening in developmental crashes do not necessarily indicate 
that doors will open in production vehicles under the same crash 
conditions.

Accident Data

    In response to DP96-008 Information Request concerning reports of 
inadvertent side door openings on the subject vehicles involved in a 
collision or rollover, GM's September 5, 1996 response did not limit 
the reports to those involving a ``bypass'' although the petition 
focused on that type of door latch failure. According to GM, it has 
provided reports involving all door openings regardless of the causes, 
which include side door openings caused by something other than door 
latch failure. Further, GM indicated that door openings can and do 
result from many causes including intentional or accidental actuation 
of the door handle, or vehicle crash damage to the actuating rods 
inside the door, the door hinges, the door pillar or other parts of the 
door system.
    Analysis of GM's September 5, 1996 response indicates that: (a) the 
majority of door-opening cases occurred from high speed collisions, and 
(b) under high speed collisions, both the original and modified latches 
cannot always prevent side door opening.

1. Accident Reports and Lawsuits

    GM reported 19 accident reports and 105 lawsuits involving side 
door openings in the subject vehicles. In the 45 cases where the posted 
speed limits were reported, all of the accidents occurred in areas 
where the posted speed limits were 35 mph or higher, and eighty percent 
of the accidents occurred on roadways where the posted speed limits 
were 50 mph or higher. In the 38 cases where the estimated impact 
speeds were reported, all of the accidents occurred at an estimated 
impact speed of 36 mph or higher. In cases where neither the posted 
speed limits nor the estimated impact speeds were reported, almost all 
the vehicles were declared a total loss.
    Of the 45 cases where the posted speed limits were reported, 29 
involved the original Type III latch and 16 involved the modified Type 
III latch. Similarly, of the 38 cases where the estimated impact speeds 
were reported, 25 involved the original Type III latch and 13 involved 
the modified latch. One would expect to have more accident cases 
involving the subject vehicles with the original Type III latch than 
those with the modified Type III latch because there were 40 million 
vehicles equipped with the original Type III latch and only 6 million 
vehicles equipped with the modified latch.

2. Survey

    Unlike other manufacturers, GM owns an insurance company that 
provides it with collision performance and injury reports (CPIR) on the 
crashworthiness of certain new model GM vehicles. GM provided NHTSA 
with 322 CPIRs involving side door openings during a collision and 265 
of which involved Type III latches.
    Analysis of the 265 CPIRs involving Type III latches showed that 
243 cases included the posted speed limits in the reports. Eighty-six 
(86) percent of the accidents occurred on roadways where the posted 
speed limits were 35 mph or higher, and 50 percent of the accidents 
occurred on roadways where the posted speed limits were 50 mph or 
higher. Eighty-one (81) cases included the estimated impact speeds in 
the reports. Among those cases, 83 percent of the accidents occurred at 
an estimated impact speed of 35 mph or higher, and 48 percent of the 
accidents occurred at an estimated impact speed of 50 mph or higher.
    Based on the accident reports, lawsuits, and CPIR cases provided, 
the difference between the number of door opening cases for vehicles 
equipped with the GM's original Type III latch and that with the 
modified Type III latch is not statistically significant.

3. Analysis of FARS and NASS Data--Performed by ODI

    Accident data were analyzed to determine the ``real world'' 
performance of the subject vehicles and peer vehicles.
    ODI's analysis was based on a peer vehicle comparison, i.e., GM 
vehicles with the original Type III latch compared to vehicles 
manufactured by other companies that are similar in size and/or use. 
Data analyses were conducted, using these two vehicle sets, using both 
NHTSA's Fatal Accident Reporting System (FARS) and National Accident 
Sampling System (NASS) Crashworthiness Data System (CDS) data.
    Vehicle Selection and Peer Sets. The GM vehicles which used the 
original Type III latch were organized according to type and size. A 
peer vehicle group was selected according to size and type to be 
similar to those of the GM vehicle group.
    Results of the analysis showed that:
    a. Analysis of the NASS-CDS database indicated that the GM vehicles 
equipped with the original Type III latch without the support plate 
performed in a similar manner as the peer vehicle group, i.e., the 
rates of ejections, door openings, or latch failures for the GM 
vehicles equipped with the original Type III latch were about the same 
as those of the peer vehicles.
    b. Analysis of the FARS data base indicated that the GM vehicle 
group performed no worse than the peer vehicle group, i.e., the 
ejection rates for the GM vehicle group equipped with the original Type 
III latch, involving fatally injured occupants and ejected occupants, 
were about the same as those of the peer vehicle group.
    c. Analysis using both FARS and NASS data indicated that during 
rollover crashes, the vehicle group equipped with the original GM Type 
III latch performed the same as the peer vehicle group, i.e., the 
ejection rates for the GM vehicle group equipped with the original Type 
III latch were about the same as those of the peer vehicle group.
    d. Analysis using both FARS and NASS data indicated that unbelted 
occupants in crashes in the vehicle group equipped with the original GM 
Type III latch performed the same as the peer vehicle group.

4. Analysis of FARS and NASS Data--Performed by GM

    GM submitted to NHTSA a report dated September 25, 1996, including 
accident data analyses of the ``real world'' performance of the subject 
vehicles equipped with the original Type III latch. These analyses were 
developed from NHTSA's FARS and NASS-CDS data systems. GM's summary 
stated that ``GM vehicles equipped with Type III door latches have no 
higher rate of door opening than vehicles made by other manufacturers 
at the same time. Even

[[Page 64567]]

more importantly, GM vehicles with Type III door latches have no higher 
rate of ejection--either overall or through side-door openings--than 
contemporaneous vehicles of other manufacturers. * * * ''
    Using 1984-94 NASS data, GM's detailed analysis indicates that the 
GM and non-GM vehicles have similar door opening rates.
    GM conducted several analyses using NHTSA's FARS data. Details of 
these analyses are summarized below.
    Overall ejection rate: In an analysis using 28 different car lines 
of unbelted front seat outboard occupants in model year 1978 through 
1987 passenger cars that were involved in fatal collisions in FARS 
years 1975-1994, GM determined the number of ejected occupants per 100 
unbelted occupants. The results showed that GM vehicles had the second 
to lowest ejection rate, i.e., approximately 17 ejections per 100 
unbelted occupants in fatal crashes.
    Side door ejection rate: In a similar analysis using the number of 
ejections through side door openings in 1978 through 1987 passenger 
cars in the 1991 through 1994 FARS files, GM found a median ejection 
rate of about 1.8 unbelted front seat outboard occupants per 100 
unbelted occupants in fatal crashes. The GM vehicles had a side door 
opening ejection rate of about 1.6 front seat outboard occupants per 
100 unbelted occupants in fatal crashes.
    Rollover ejection rates: GM presented an analysis of rollover and 
non-rollover crashes, comparing its vehicles that used the original 
Type III latch with other manufacturer's vehicles. The analysis shows 
that the overall ejection rate for GM cars equipped with the Type III 
latch was lower than that for five other manufacturers' cars, and the 
side door ejection rate for GM cars equipped with the Type III latch 
was lower than that for four other manufacturers' cars.
    Make/Model analysis: GM analyzed FARS data concerning the ejection 
rate of front seat occupants in vehicles at the make-model level for 
four different vehicles: GM's S-10 pickup, GM's A body cars (Chevrolet 
Chevelle/Malibu, Pontiac Lemans/6000, Oldsmobile Cutlas/Ciera, and 
Buick Century), Ford Ranger and Ford Taurus. The results showed that 
the ejection rate of the S-10 pickups was lower than that of the 
Rangers for both overall and side door ejections, and the overall 
ejection rate of the A body cars was lower than that of the Taurus. For 
side doors, the ejection rate was the same for the A body cars and the 
Taurus.

Summary

    1. The GM original Type III door latch has performed better than 
many other side door latches used in GM and non-GM vehicles, in both 
static and dynamic tests, in the laboratory and in the field.
    2. Test and accident data indicate that vehicle side door openings 
did occur under certain crash conditions for all vehicles, regardless 
of vehicle make or model, including GM vehicles equipped with the 
modified Type III door latch as well as GM vehicles equipped with the 
original Type III door latches. Most crashes in which the side door 
opened were high speed crashes.
    3. ``Real-world'' accident data indicate that GM vehicles equipped 
with the original Type III door latch have ejection rates or side door 
opening rates similar to or lower than those of vehicles made by other 
manufacturers.
    4. There was only one complaint in the ODI database concerning an 
alleged side door opening during a collision accident involving a 
subject vehicle.
    Based on the information available at the present time, no defect 
trend has been identified for the GM Type III door latch in 1978 
through 1988 GM vehicles.
    For the foregoing reasons and for the reasons stated in the ODI 
report, further expenditure of the agency's investigative resources on 
the allegation in the petition does not appear to be warranted. 
Therefore, the petition is denied.

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

    Issued on November 27, 1996.
Michael B. Brownlee,
Associate Administrator for Safety Assurance.
[FR Doc. 96-30773 Filed 12-4-96; 8:45 am]
BILLING CODE 4910-59-P