[Federal Register Volume 66, Number 184 (Friday, September 21, 2001)]
[Notices]
[Pages 48737-48738]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 01-23686]


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DEPARTMENT OF TRANSPORTATION

National Highway Traffic Safety Administration


Denial of Motor Vehicle Defect Petition

AGENCY: National Highway Traffic Safety Administration (NHTSA), 
Department of Transportation.

ACTION: Denial of petition to open a defect investigation.

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SUMMARY: This notice sets forth the reasons for the denial of a 
petition submitted by Mr. John E. Ballow, dated July 20, 2000, to NHTSA 
under 49 U.S.C. 30162, which requested the agency to commence a 
proceeding to determine the existence of a defect related to motor 
vehicle safety in certain General Motors (GM) vehicles equipped with 
flex fans (part number 336032). After reviewing the petition and other 
information, NHTSA has concluded that further expenditure of the 
agency's investigative resources on the issues raised by the petition 
does not appear to be warranted. The agency accordingly denies the 
petition.

FOR FURTHER INFORMATION CONTACT: Mr. Frank Borris, Safety Defects 
Engineer, Vehicle Integrity Division, Office of Defects Investigation, 
NHTSA, 400 Seventh Street, SW, Washington, DC 20590. Telephone (202) 
366-5202.

SUPPLEMENTARY INFORMATION: In a letter dated July 20, 2000, John E. 
Ballow, an attorney in Buffalo, New York, petitioned NHTSA to conduct 
an investigation of a certain GM flexible blade engine cooling fan and, 
if later warranted, all flexible radiator fans offered as original 
equipment in GM vehicles, particularly light duty trucks. The 
petitioner specifically identified GM Part No. 336032 and alleged that 
additional injuries have been caused by this component since NHTSA last 
considered this issue in 1996. Enclosed with the petitioner's letter 
were opinions and analyses from four independent experts in fan 
engineering, failure analysis, engine design, and human factors 
engineering. As an enclosure to a supplementary letter dated September 
26, 2000, the petitioner provided numerous photographs depicting the 
severity of injuries allegedly resulting from separated flex fan 
blades. NHTSA's Office of Defects Investigation (ODI) conducted a 
Petition Analysis to determine whether to grant the petition.
    The subject fan is a 7-blade, flexible blade engine cooling fan 
commonly referred to as a ``flex fan,'' which was used on approximately 
2.6 million GM vehicles that were produced without air conditioning and 
with heavy duty cooling systems. The model years and models in which 
the fans were used are model year (MY) 1973 through 1979 Chevrolet and 
GMC C/K 10, 20, and 30 series light duty trucks and the MY 1975 
Chevrolet and GMC ``G'' van (subject vehicles). The flex fan concept 
was used by many vehicle manufacturers as a way to improve fuel 
efficiency. Like all flex fans, the subject fan has flexible metal 
blades, which are attached to the fan hub or ``spider'' by rivets, and 
are designed to flex or ``flatten out'' as the engine speed is 
increased, thus reducing the load on the engine. However, the subject 
fans may be susceptible to fatigue failure of the blade resulting from 
uncontrolled flexing (bending) due to a resonant condition.
    Prior to this petition, NHTSA analyzed failures of the 336032 flex 
fan in response to a similar petition, DP96-007. In a letter dated May 
17, 1996, Mary Walsh-Dempsey, an attorney in Scranton, Pennsylvania, 
petitioned NHTSA to initiate a defect investigation regarding MY 1976 
Chevrolet C10 trucks concerning blade separation of the same engine 
cooling fan (Part No. 336032). On December 3, 1996, NHTSA denied the 
Walsh-Dempsey petition based on evidence showing a low failure rate, 
along with some consideration of the subject vehicles' age and 
remaining useful life.
    After receiving the Ballow petition, NHTSA requested certain 
information from GM, requested additional information from the 
Petitioner, searched its database for reports of fan blade separations, 
and reviewed the experts' reports and credentials.
    The subject fan was originally produced for GM by Canadian Fram,\1\ 
which ceased production in approximately 1993. It was at this time that 
GM made a one-time purchase to maintain an inventory for future service 
parts. New replacements of the subject fan are available only from GM 
dealerships, although used units may still be available from automotive 
salvage businesses. At the time of this writing, GM estimates its 
inventory to be approximately 500 units. Part sales of the subject fan 
from GM dealers over the last four calendar years (1997-2000) averaged 
211 units per year.
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    \1\ Canadian Fram, Ltd., was acquired by Bendix Engine 
Components, Ltd., which was acquired by Allied Signal, Inc., which 
was acquired by Siemans Automotive, Ltd.
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    NHTSA has identified four reports of alleged failure of the subject 
fan since December 3, 1996, when DP96-007 was denied. Each report 
alleges an injury. These incidents occurred between January 1998 and 
September 2000. Reports on two of these incidents were provided by GM 
with the remaining two coming from NHTSA's database and the petitioner. 
One of the GM reports includes color photographs indicating the owner 
was struck in the neck and shoulder, requiring hospitalization.
    GM's response also included two reports prepared by Canadian Fram 
for Chevrolet Engineering following its analysis of failed subject 
fans. Each of the reports, dated June 1978 and February 1979 
respectively, documents findings that:

[[Page 48738]]

     The failure was due to fatigue cracking;
     The crack initiated near the third rivet on the concave 
(engine side) of the blade under the deflection limiting cap (below the 
visible surface); and
     There was no evidence of prior mechanical damage.
    The author of each report concluded that the failure resulted from 
``a resonant condition in the particular vehicle.'' Experts working on 
behalf of the Petitioner offered similar findings after examining 
failed subject fans. One of the experts, a recognized authority in the 
fan industry and author/editor of the 6th, 7th, and 8th editions of Fan 
Engineering, examined the remains of three failed subject fans. The 
expert reported the same findings as Canadian Fram, differing only in 
his belief that the resonant condition is inherent in all 336032 flex 
fans.
    ODI reviewed documents submitted by GM which clearly indicate that 
fatigue failure was an issue of concern to GM engineers. Numerous tests 
were performed on the subject flex fan by Canadian Fram and GM 
Engineering between 1973 and 1979 to both validate fan performance and 
to measure strains imparted to the fan assembly. However, the testing 
methods employed by and for GM were questionable. For example, in order 
to measure strain on the fan blade, GM engineers instrumented the fan 
blades with strain gauges while rotating the subject fan on an 
apparatus to simulate the rotational inputs of the engine. The location 
of the strain gauges was determined by coating the visible surface of 
the subject fan blade with stresscoat \2\ and observing the location 
and magnitude of cracks in the stresscoat resulting from rotating the 
fan at various speeds. However, as mentioned earlier, field experience 
has shown cracks in the subject fan blades tend to develop at a 
location on the blade below the visible surface. According to documents 
submitted by GM, all strain measurements with respect to the blade were 
taken only on the visible blade surface. Moreover, there is no 
indication that GM test engineers disassembled test specimens to 
inspect for the presence of cracks below the cap.
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    \2\ Also known as brittle lacquer, stresscoat is a liquid 
coating applied to a test surface and allowed to harden. As the 
surface is stressed during operation, cracks form in the stresscoat 
indicating areas of deformation (strain).
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    The subject fan is not the only flexible blade fan installed as 
original equipment by GM. In fact, it is one of a total of 38 unique 
part numbers for flexible blade fans representing more than 7,100,000 
fans in addition to the 2,600,000 subject fans. However, the subject 
fan is over-represented with respect to the number of lawsuits brought 
against GM. ODI requested information from GM describing all lawsuits, 
out-of-court settlements, and offers of goodwill where GM is a party 
and which pertain to the performance of any GM fan, including fixed-
pitch fans. GM's response includes information on 55 lawsuits alleging 
separation of a fan blade. Of this number, at least 49 (89%) identify 
the subject fan, two are unidentified, and four are other GM flex fans. 
None of the lawsuits, or any reports submitted by GM, allege a fan 
blade separation of a fixed-pitch fan.
    In its response to ODI, GM attributed fan blade separation to the 
following:
     Reuse of fans with bent or broken blades;
     Preexisting, collision-induced damage;
     Interference with other engine compartment components;
     Water pump malfunctions; and
     Misapplication of the fan with drive train components not 
intended by GM.
    As mentioned above, there have been four injury reports related to 
blade separation in the subject fan since December 3, 1996, when DP96-
007 was denied. The estimated exposure based on the registered vehicle 
population of the subject vehicles for calendar years 1997 through May 
2001 is 2.8 million vehicle years, yielding a failure rate of 0.14 per 
one hundred thousand vehicle years of exposure. It should be noted that 
this number does not represent the rate of flex fan blade separation 
but only the rate of reports.
    Due to the potential for fatal or debilitating injuries associated 
with flex fan blade separation, ODI decided to enter into discussions 
with GM in which it urged GM to provide vehicle owners and mechanics 
with a warning about the safety risks. As a result of those 
discussions, GM agreed that it would send notification letters to 
owners of vehicles with the subject flex fan warning them of the 
potential for serious or fatal injuries resulting from flex fan blade 
separation and suggesting that they obtain a replacement fan.
    Beginning the week of April 16, 2001, GM began mailing letters to 
affected owners warning of the potential for injury if failure were to 
occur and urging them to replace the fan regardless of its condition. 
The letter includes a picture and detailed description of the subject 
fan and reiterates that initial fatigue cracks may not be visible. In 
order to provide owners with some options for fan replacement, GM 
initiated production of a 4-blade, fixed-pitch fan (GM part number 
461317) for distribution to GM dealerships and also suggested that 
owners consider purchasing such fans from after-market suppliers. GM 
also agreed to notify its dealers to stop sale of the subject fan and 
return any remaining inventory to GM.
    In order to further minimize the potential for future injuries 
related to the subject fan, ODI contacted the Governmental and Industry 
Relations Office of the American Recyclers Association (ARA) to 
increase awareness of this issue and request their assistance in 
informing their membership. The ARA represents approximately 2,000 
member companies through direct membership and over 3,000 other 
companies through 52 affiliated chapters. In response to ODI's request, 
the ARA notified its membership via electronic mail of GM's efforts 
with respect to the subject flex fan and suggested that they also stop 
the sale of the subject flex fan. Although the GM action is not a 
formal safety recall, it will help to make owners aware of the 
potential safety problem and encourage them to replace this fan.
    After reviewing the petition and its supporting materials, as well 
as information furnished by GM and information within the agency's 
possession from previous investigations and other related actions, 
NHTSA has concluded that further investigation of the subject vehicles 
concerning the alleged fan failure is not likely to lead to a decision 
that the vehicles contain a safety defect. This is primarily based on 
the very large number of exposure years and the low failure rate, the 
age of the vehicles (22 to 28 years old), and the actions taken by GM 
and ARA.
    For the foregoing reasons, 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 49 
CFR 1.50 and 501.8.

Kenneth N. Weinstein,
Associate Administrator for Safety Assurance.
[FR Doc. 01-23686 Filed 9-20-01; 8:45 am]
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