BMW HVAC Blower Wiring Recall

BMW logo

R. Scott King, BSME, Sr. Automotive / Mechanical Engineer ::::
Earlier this month, BMW announced it is recalling over 600,000 3-Series vehicles manufactured between 2006 and 2011 over concerns of potential fire risk. According to documents filed with NHTSA, BMW initiated this recall upon learning of a September 2017 incident involving a vehicle fire it deemed related to the heater and air-conditioning fan wiring. The defect, according to BMW, is the result of microscopic wear, or “fretting”, between the mating components of the electrical connectors. Over time, and with continued wear, electrical resistance between the mated connector halves can increase, resulting in excessive electrical current passing through the connector, which in-turn leads to excess heat. This heat first melts the plastic encasing the connectors, then in the extreme case, ignites it.
Notable in the NHTSA filings, however, is the investigative chronology associated with this recall. As those records show, BMW first became aware of this potential fire risk as early as a decade ago. Specifically, BMW investigated two incidents, one occurring in late 2007 and another in 2008, both “involving heat related damage to the heating and cooling system”. At the time, no root-cause of the damage was identified. Then, between 2010 and 2011, more incidents were reported and investigated. This time however, BMW concluded the root-cause was related to deterioration (fretting) within the electrical connections in the fan wiring. This finding led BMW to change to the metallurgical properties of the wiring connectors; however, the change was implemented in new vehicles only beginning in 2012; no modifications to the existing vehicle population were offered. BMW also indicates that between 2007 and 2014, it had received no reports of injuries related to this concern; however, in 2015, it learned of three such incidents. Continue reading “BMW HVAC Blower Wiring Recall”

Obstructive Sleep Apnea and Commercial Vehicles

sleep-apnea-mechanical-engineer-expert

R. Scott King, BSME, Senior Automotive / Mechanical Engineer ::::
The Federal Motor Carrier Safety Administration has decided to withdraw a March 2016 Advanced Notice of Proposed Rulemaking (ANPRN) related to commercial vehicle operators and Obstructive Sleep Apnea. The so-called Pre-Rule was issued to investigate what actions, if any, the FMSCA should take to mitigate the risks associated with OSA. Derived from the Greek word meaning “without breath”, an estimated 18 million adults in the US suffering from OSA will cease breathing during sleep, often as long as 30 seconds and hundreds of times each sleep cycle. Experts indicate that the effects of OSA include deficits in concentration, memory, and situational awareness. It was these potential effects on commercial vehicle operators and highway safety that became the genesis of the proposed rule. Continue reading “Obstructive Sleep Apnea and Commercial Vehicles”

The Count-Down to Electronic Logging Devices

trucks

R. Scott King, BSME, Sr. Automotive / Mechanical Engineer ::::
Commercial vehicle operators have long been required to comply with federally-mandated hours-of-service rules that control and limit driving time. While the rules have changed over the years, particularly the amount of daily and weekly drive time, the primary objective of such rules has remained constant: to reduce fatigue-related commercial vehicle crashes and related injuries and death.
Historically, commercial vehicle operators have been required to maintain their own hours-of-service records on paper logbooks. This honor-based system had its critics, to be sure, and apparently included the Federal Motor Carrier Safety Administration. This is because the FMCSA has, for over half a decade, been pursuing the replacement of the paper logbook with the so-called Electronic Logging Device.
After much debate between and within the motor carrier, driver, and technology sectors, the Final Rule, published in the Federal Register on December 16, 2015, establishes extensive ELD performance criteria, new protections against driver harassment, and contingency provisions for equipment failure.
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Modified Vehicle Controls

Vehicle Controls

R. Scott King, BSME, Automotive / Mechanical Engineer ::::
The operator of a new, customized van equipped with specialized hand-controls was fatally injured in a single-vehicle incident when his van reportedly accelerated uncontrollably and struck a tree. After the incident, investigators downloaded data from the vehicle’s event data recorder and determined the vehicle speed exceeded 90 miles per hour. A witness described the operator’s panicked efforts to maintain control of the vehicle as it accelerated and swerved through traffic before departing the roadway.
Review of the vehicle modification records, as well as the training and certification materials provided with the modification equipment, revealed operational details of the modifications to the vehicle’s accelerator and braking systems, how those systems operated, and various safe-guards associated with them. In particular, this data showed that the vehicle’s accelerator pedal was adapted to permit both hand and foot operation. The safe-guard for this portion of operation required the use of a pedal block, designed to prevent unintended foot operation of the accelerator pedal while operating under hand control. Such safe-guarding was required as some disabled people, including the subject operator, suffer from involuntary leg and foot motion.
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Mechanic Does Double-Duty at the Airport

Shuttle Service

R. Scott King, BSME, Automotive/Mechanical Engineer ::::
Case Synopsis: An airport shuttle driver, doubling as an ad-hoc vehicle mechanic, was fatally injured when the vehicle he was working beneath collapsed. The preliminary investigation revealed that the vehicle collapsed because the jack-stand being used to support it sank slowly into the heat-softened macadam. While it sank, the stand began to tilt, shifting the load-point forward resulting in an ever-worsening problem. Video footage showed the sinking was imperceptible until the final moment of collapse.
Expert Analysis: Plaintiff’s team of experts examined the vehicle, the jack-stand, and the macadam. Together they identified what the decedent was working on beneath the vehicle and why, as well as how and why the vehicle collapsed. Plaintiff’s attorneys also reviewed the policies and practices of the shuttle service’s additional facilities in other cities and found that the incident facility was the only one that permitted ad-hoc vehicle repair.
Defendants argued that the decedent employed improper equipment and service procedures; however, the plaintiff argued that lack of adequate equipment, training and oversight was the root cause of the incident.
Result: All parties settled shortly before trial.
R. Scott King is an Automotive/Mechanical Engineer with DJS Associates and can be reached via email at experts@forensicDJS.com or via phone at 215-659-2010.

Rear Axle Failure: Before or After Incident?

2001 Ford Winstar Minivan

R. Scott King, BSME, Automotive/Mechanical Engineer ::::
Case Synopsis: The operator of a 2001 Ford Windstar minivan was injured when his vehicle suddenly veered off of the highway and struck a guiderail. The investigating police officer performed a cursory vehicle examination and determined that the rear axle beam was broken; however, he could not determine whether the axle failed before, or as a result of, the incident.
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Weld vs. Replace Results in Injury

Tractor Trailer Mechanic Accident

R. Scott King, BMSE, Automotive / Mechanical Engineer ::::
Case Synopsis: A tractor-trailer mechanic was severely and permanently injured while servicing the air-ride suspension system on a commercial trailer. Witnesses reported that the mechanic was beginning to diagnose and remedy a malfunction of a suspension system air bag when the air bag suddenly dislodged from its mounting base, striking the mechanic in the face and head.
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