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A
Primer on Crashworthiness
FOR THE NON-CRASHWORTHINESS
LAWYER
July, 2001
DAVID
L. PERRY Perry & Haas, L.L.P.
Specific
Well-Known Defects
Post-Collision
Fire |
Tire Failure | SUV
and Van Rollovers
Roof Crush | Restraint
System Defects
Post-Collision
Fire
Post-collision
fuel-fed fire, due to puncture of the fuel tank during collisions,
was one of the earliest and most widely publicized types of crashworthiness
cases. Although much reduced in frequency, such cases still occur
today.
Classic
fuel-fed fire cases involve a catastrophic fire which occurs almost
immediately upon impact, frequently engulfing the passenger compartment
before the vehicle has come to a stop, and resulting in severe burn
injury or death. Although the greatest publicity involved the Ford
Pinto and the GM side-saddle light trucks, many other vehicles are
subject to such events. Virtually all American-made passenger cars
manufactured before the early 1980s placed fuel tanks in a vulnerable
position behind the rear axle, subjecting them to grave danger in
rear-end collisions. During the 1980s, the advent of front-wheel
drive, and the corresponding placement of fuel tanks in more protected
locations, greatly reduced the risk of fire for many vehicles. But,
even recent models of full-size Ford Crown Victorias, Mercury Grand
Marquis', and Lincoln Town Cars, as well as Ford Mustangs, are the
subject of continuing fire, deaths, and injuries. The most recent
publicity associated with fuel-fed fire cases involved Anderson
v. GM in which a California jury returned a verdict for $4 billion
in punitive damages involving a 1979 Chevrolet Malibu car in which
an entire family was severely burned.
In
contrast to the sudden, almost explosive development of the classic
fuel-fed fire, there is a class of slowly developing post-collision
fires which usually begin in the vicinity of the engine compartment
and slowly engulf the passenger compartment. In cases in which an
occupant has been trapped in the passenger compartment, these slowly
developing fires can be equally as devastating as more traditional
conflagrations.
In
addition to passenger cars and light trucks, there has been considerable
litigation over the fuel system integrity of heavy trucks. Many
heavy trucks have side-saddle fuel tanks mounted in extremely vulnerable
locations which can give rise to catastrophic results in the event
of collision.
Any
burn death or serious burn injury following a collision should be
investigated as a potential crashworthiness case.
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Tire Failure
Tire
failures are widely known due to the recent news involving recalls
of Firestone ATX and Wilderness tires used on Ford Explorer SUVs.
It
is important to recognize that the problem and the defects are not
limited to the tires which have been recalled, or to Ford and Firestone
products.
The
failures in the Ford-Firestone cases, and in most modern tire cases,
involve a detreading failure of a steel-belted radial tire, in which
the tread and, frequently, the outer steel belt separate, either
partially or entirely, from the remainder of the tire. The tire
may or may not lose air. The loss of tread may result in the loss
of the driver’s ability to control the directional stability
of the vehicle, with a resulting collision, frequently, and especially
in SUVs, in a rollover.
Tire
detreading events are known to occur in virtually all types of modern
steel belted radial tires made by all manufacturers. Although Firestone
has received the most recent publicity, well-known cases have been
prosecuted successfully against Michelin, Cooper, and other manufacturers.
Any detread should be considered a potential crashworthiness case.
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SUV and Van Rollovers
A
high percentage of serious, injury-producing crashes involve SUVs,
minivans or large 15-passenger vans, all of which frequently roll
over during collisions.
Instability
leading to rollover is a well-known defect which affects virtually
all compact SUVs, minivans and 15-passenger vans. There have been
numerous cases against almost all brands and model years of compact
SUVs — Ford Bronco II, Ford Explorer, Isuzu Rodeo, Toyota 4-Runner,
Jeep CJ, Chrysler minivans, and Ford Aerostar are only the most
well-known. Ford, Chrysler, and GM 15-passenger vans are also the
subject of repeated litigation.
In
addition to the stability defect, many of these vehicles are known
to have other defects which contribute to injury severity, both
in the presence and absence of rollover. Ejections during rollover
are very common in these vehicles due to restraint or door defects.
Restraint systems that do not lock in rollovers, inertial seatbelt
buckles that unlatch, seats that do not remain securely fastened
to the floor and which destroy the effectiveness of the restraint
system are among the known problems. Doors that do not remain closed
(e.g. Chrysler liftgates and Explorer side doors) are known problems
which affect main doors as well as tailgates and sliding side doors
of many vehicles.
It
may well require considerable expert accident reconstruction to
determine whether stability was the actual cause of a specific rollover,
but any catastrophic injury or death in an SUV, minivan, or 15-passenger
van rollover should be viewed with suspicion, especially if ejection
is involved. Immediate steps should be taken to determine seatbelt
usage for the injured.
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Roof Crush
Roof
crush defects affect virtually any passenger car, SUV, minivan,
or light truck sold in America.
FMVSS
216, the Federal Motor Vehicle Safety Standard which applies to
roof strength, allows vehicle roof structure to be so weak as to
be a meaningless standard. Modern vehicles frequently comply with
FMVSS 216 test requirements based on the strength provided by side
window glass which is closed when the tests are conducted. When
the glass shatters during a collision, the roof no longer provides
even the minimal strength of the meaningless Federal standard.
As
a result, it is common to find cars and trucks of virtually any
make or model with the roof crushed to the top of the seats following
a rollover.
One
of the side effects of the widespread use of lap-shoulder belts
is the tendency to cause the occupant to remain upright during a
rollover. Studies show that, during rollover events, centrifugal
force tends to position the head of the occupant against the roof
rail. When the roof crushes, and the roof rail forcibly intrudes
into the passenger compartment, compression loading of the neck
axially to the spinal column can result in head injuries or neck
fractures leading to death or quadriplegia.
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Restraint System Defects
Modern
automotive safety depends heavily on the proper functioning of the
restraint system. This term includes, but is broader than, seatbelts.
The restraint system also includes the seats, head restraints, airbags,
portions of the steering column, instrument panel and doors, and
various devices associated with these items. Various well-known
defects are associated with almost all aspects of restraints systems
in a wide variety of cars and trucks.
The
list below is not exclusive, but is an indication of the scope of
known defects:
Inertial Unlatching
Under
certain circumstances, the inertial forces in collisions can cause
seatbelt buckles to become unlatched during the collision process.
Lawyers have demonstrated the simple process in what manufacturers
call a "parlor trick" by striking a latched buckle on
the back and causing the inertial forces to unlatch the buckle,
allowing the latch plate to fall free.
The
actual process of inertial unlatching is substantially more complicated
than the simple "parlor trick," and far more deadly.
The manufacturers have claimed for many years that there is no
documented case in which a buckle has actually unlatched in a
crash, and succeeded in persuading NHTSA to make a finding that
the buckles are not defective, and that there is no known case
of buckle unlatching in a crash.
Recently,
we forced General Motors to produce approximately 60 crash tests
in which the unlatching of the GM--Allied Signal JDC buckle is
documented on videotape. Even though actual unlatching can now
be seen on video, proof that a particular buckle was latched prior
to a collision and became unlatched during the collision process
can be difficult. In some cases, we have used sophisticated computer
aided kinematic reconstructions of the movements of the persons
in the vehicle to demonstrate that the buckle must necessarily
have been latched and then become unlatched in the particular
collision.
Closely
related to inertial unlatching is the phenomenon of "false
latching." In this case, the buckle may be closed and appear
to be latched when it is not. During a collision, the movement
of the body, which is intended to be restrained by the belt, will
pull the buckle free. Federal regulations require that buckles
which are "false latched" must pull free at less than
5 pounds of pull, so that the simple "tug" which many
people give a buckle after latching will pull the buckle free
if it is not properly latched. Unfortunately, we have found buckles
which required 30-45 pounds of pull to become free, a clear violation
of the safety standards.
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Retractor
Lock-Up Failure
During
normal driving, seatbelts spool in and out from spring-loaded
retractor reels which provide more length to accommodate movement
while riding in the vehicle, and reel in the extra length when
not needed. During a collision, locking mechanisms within the
retractor are intended to sense the impending collision and to
lock the belt so that it can restrain the occupant without reeling
out.
There
are various kinds of locking devices of varying sophistication
and reliability. Unfortunately, it is all too common that the
locking devices will fail to promptly and fully lock. This may
result in a complete failure to provide restraint, or a failure
to provide pelvic or torso restraint, or late or incomplete restraint.
As a result, the occupant may receive far more severe injuries
than appropriate for the severity of the collision.
There
are various alternative designs to assure full and proper lock
up. Most desirable is the use of pretensioners, which are devices
to not only lock seatbelts but to affirmatively pull them tight
in the face of impending collision. Pretensioners are fired electronically
by signals from the sensors which sense impending collisions and
fire air bags. The sensors may be located and calibrated to sense
impact from varying directions, and to sense impending rollover.
Submarining
Failure
to properly design the restraint system may result in the occupant
submarining under the lap portion of the seatbelt.
The
lap belt portion of seatbelt should be designed to apply restraint
across the heavy bony portions of the pelvis below the abdomen.
During collisions, however, the pelvis and buttocks of the occupant
tend to move forward and downward; with poorly designed restraint
systems, the pelvis will move forward under the belt (submarine)
which will now apply force through the abdomen to the soft tissues
of the abdomen and the spinal column behind. These structures
are not strong enough to withstand such loading, and the belt
itself may cause serious or fatal injury. Severe bruising and
laceration of internal organs may occur, sometimes including internal
hemorrhaging which may be fatal. Major damage to the lumbar spinal
column and spinal cord may result in paraplegia or other neurological
damage affecting the lower limbs and bladder or bowel control.
Submarining
is the result of improper design of seatbelt anchor points, which
affect belt angles, and improper seat design. Properly designed
seat cushions and seat pans underlying the cushions assist in
providing restraint to the pelvis and buttocks to prevent submarining.
Failure to provide this important restraint can allow the belt
to maim or kill the occupant it should have protected.
Injuries
focused on the abdomen or spinal column in occupants who were
known to be belted, point strongly toward seatbelt injuries and
should be considered potential crashworthiness cases.
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Poor
Belt Fit — Women and Children
Often
related to submarining is the problem of poor belt fit, especially
for small women and children. Belts and seats are frequently designed
to fit 50-95th percentile men, although they are required
by law to fit 5th percentile female through 95th
percentile men in the driver’s seat, and 6-year-old children
through 95th percentile men in rear seats. When seats
and belts do not properly fit small women and children, the poor
fit can contribute to submarining. Lap belt placement which may
be adequate for a 50th percentile male may be too high
for a small female or 10-year-old child, thus contributing to
submarining and abdominal or spinal injury.
Poor
belt fit can cause other problems as well. Torso belt anchor placement
that is excessively high or forward in comparison to the size
of the occupant can result in failure to provide proper torso
restraint, especially in frontal collisions which have a substantial
offset or angular component. The occupant can roll or slip out
of the torso belt with resultant head impact into structures in
front of the occupant.
Notwithstanding
the requirements to fit women and children, many vehicles are
designed with little or no testing of belt fit and little or no
consideration of crash performance on women and children. Recently,
NHTSA has published a Parents’ Guide to Child Restraints
which advocates use of booster seats to make belts fit children
too old for child seats, but too small to fit adult seatbelts
— generally from ages 4 to 14. Unfortunately, vehicle manufacturers
only rarely supply booster seats or other devices to fit seatbelts
to children in the "forgotten age" bracket.
As
mentioned above, injuries related to the abdomen or spinal column
point strongly toward seatbelt injuries, especially in women and
children. In addition, unexplained major torso, facial, neck,
or head injuries in women and children should be investigated
as possible crashworthiness failures.
Lap-Only Belts
Not
until 1988 did Federal standards require lap-shoulder belts in
the rear outboard seating positions of American cars and trucks.
Prior to that model year, almost all cars and trucks sold in the
United States provided lap-only belts in all rear seating positions.
Still
today, most manufacturers provide lap-only belts in the rear center
seating position. The
absence of the torso restraint exposes the occupant to all the
dangers of an unrestrained head and upper body. Additionally,
the belts frequently allow submarining. The combination of no
torso restraint and submarining commonly results in abdominal
and spinal column injuries resulting in severe internal injuries,
including bleeding which may be fatal, or spinal cord injury with
resulting paraplegia or paraparisis.
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Injuries
from any of these should be suspect:
Energy
Management Loops
Several
manufacturers incorporate so-called "energy management loops"
into their seatbelts. These are actual loops of seatbelt which
are stitched into the belt with stitching designed to rip out
when collision force loading is applied to the belt, which will
result in lengthening the belt by several inches. The additional
length creates slack in the belt which results in some failure
of restraint which may be injurious. Additionally, in some situations
the slack can allow the occupant to slide free of the belt and
to be ejected or thrown forcefully around inside the vehicle.
Child
Seats
State
laws requiring, and public relations campaigns encouraging, the
use of child seats for children under 4 years of age have highlighted
the generally poor design of the available child seats. Many child
seats simply do not do a good job of protecting children from
injury. Many are complicated to install and to use correctly,
and are not accompanied by adequate warnings and instructions.
Devices required to be in vehicles to facilitate installation
of child seats are not always available.
Young
children are especially subject to devastating injuries in collisions
due to the fragility of their young body structures. Any severe
injury to a child which occurs when the child has been located
in the rear seat and is using the restraints available should
be suspect.
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Airbags
Airbag
injuries are of two types:
- Failure
to deploy
- Injury
due to deployment
Before
considering a failure to deploy case, it must be remembered that
frontal airbags are designed to deploy only in collisions which
are fairly severe and generally frontal in direction; further,
airbags are considered to be supplemental to seatbelts by both
the industry and the public.
Cases
in which the claim is that the occupant suffered a minor to moderate
facial injury which would have been prevented by air bag deployment
are generally not viable, both because the injury is not sufficiently
severe to support a crashworthiness case, and because the collision
severity may not have been of the severity intended to trigger
the airbags. This is especially true if the injured person was
not using available seatbelts.
On
the other hand, there are occasional severe collisions in which
belted occupants suffer severe injuries and in which the airbags
never deploy, or only deploy after the vehicle has come to rest.
Such cases will require detailed biomechanical reconstruction
of the event, to determine whether the injuries would have been
prevented by proper function of the airbag, but should be considered
as potential crashworthiness cases.
Injuries
due to airbag deployment are an admitted and documented phenomenon,
but the cases are extremely complex and hard-fought. It is recognized
that the force of airbag deployment, especially for small women
sitting close to the dashboard or steering wheel, may be sufficient
to cause death. This is also true of children sitting in the front
seat, and is the reason for the campaign to seat all children
in the back seat.
The
cases are especially difficult due to the complexity of the engineering
issues of alternative design and the reconstruction and biomechanical
issues required to establish causation. Nevertheless, death due
to closed head injury of an occupant who was properly belted,
in a frontal collision, should be considered suspect, especially
in the case of a small female seated in a forward position.
Lack
of Head Restraint
Head
restraints have been required in passenger cars by Federal regulation
since 1968, and in light trucks since 1993. Prior to those years,
manufacturers almost uniformly did not install head restraints.
When installed, many head restraints are adjustable, and are routinely
used at such a low adjustment as to be ineffective.
Most
frequently, lack of head restraint results only in soft tissue
injuries to the neck which are not sufficiently severe to justify
a crashworthiness claim. However, in rare cases, lack of head
restraint may result in a broken neck and quadriplegia.
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Seatback
Failure
The
seat, including the seatback, is an essential part of the restraint
system, especially in rear-end collisions. For many years, virtually
all manufacturers provided seatbacks which were so weak as to
fail in moderate speed rear-end impacts. The fact of failure was
demonstrated repeatedly in the manufacturers’ rear-end crash
tests.
When
seatback failure occurs in a rear-end collision, the occupant
is catapulted rearward in the vehicle; seatbelt restraint becomes
ineffective, and the occupant is subjected to the danger of forcibly
impacting the interior of the vehicle with the head, which may
result in severe head injury or neck fracture which may cause
death or quadriplegia. When other occupants are in the rear seats,
the front occupant may forcefully contact the rear occupant, resulting
in injuries to both.
Door
Opening
Doors
should remain closed during collisions and, ideally, should be
openable thereafter. Federal standards have recognized this principle
for many years by imposing certain strength requirements for the
door latches of side doors.
Unfortunately,
many doors of many vehicles do not remain closed during collisions,
due to a number of various defects. Type I door latches which
open during collisions have been a source of litigation for many
years. Many vehicles use rods to connect the inner door handles
with the actual door latch; during collisions, collision forces
on the rod can unlatch the door even if locked (e.g. Ford Explorer
compression rod cases). Side doors of vans, and the liftgates
of vans and SUVs frequently use latches of poor design which routinely
open during collision (e.g. Chrysler minivan liftgate litigation).
When
the doors open, especially during rollovers or side impacts, the
occupants are exposed to the danger of ejection.
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