Investigating Material Failure Forensics Engineering

Materials Engineering UBC

12 Aug 202210:26

Summary

TLDRElvis Tepush, a forensic engineer at RJ Watering Company, investigates material and mechanical failures to determine their causes. He explains a case study involving the crash of a helicopter due to a tail rotor failure, which resulted from improper maintenance and lubrication. His team's investigation helped the insurance company recover losses. Tepush emphasizes the value of forensic engineering in providing answers, reducing uncertainty, and improving safety. By identifying the reasons behind failures, they aim to prevent future accidents, reduce injuries, and lower costs through improved processes and regulations.

Takeaways

🛠️ The speaker, Elvis Tepush, is a forensic engineer at RJ Watering Company with a background in mechanical engineering and a PhD from UBC.
🔍 The focus of forensic engineering is determining the cause of failure in materials, machines, designs, or processes.
📉 The range of failures investigated is wide, from small plumbing components to entire airplane and helicopter fuselages.
🚁 A case study of a Bell 206B helicopter crash is used to explain the forensic investigation process, where a tail rotor failure caused the crash.
🔥 The investigation revealed that misplacement of a cork led to poor lubrication in the tail rotor drive quill, causing overheating and eventual failure.
⚙️ The maintenance firm responsible for the tail rotor was found to have improperly maintained the component, leading to the accident.
⚖️ The insurance company pursued litigation to recover costs through subrogation, and the court ruled in favor of the client, awarding full compensation.
🕵️‍♂️ The forensic investigation was able to prove the maintenance firm's fault, even though they argued the cork placement was correct.
🧠 Forensic engineering often deals with uncertainty, but the goal is to provide clarity and factual accuracy in complex cases.
🔧 The ultimate value of forensic engineering is in preventing future failures, injuries, or deaths by improving manufacturing, inspection, and safety policies.

Q & A

What is the profession of Elvis Tepush, and where does he work?
-Elvis Tepush is a forensic engineer working at RJ Watering Company.
What educational background does Elvis Tepush have?
-Elvis Tepush has a background in mechanical engineering from the University of Manitoba and a PhD from the University of British Columbia (UBC).
What is the primary focus of forensic engineering according to Elvis Tepush?
-Forensic engineering focuses on determining the cause of a failure in a material, machine, design, or process, whether it’s a small component or a large structure, such as an airplane fuselage.
Can you provide an example of the range of failures that forensic engineering investigates?
-Forensic engineering investigates failures ranging from small plumbing components causing $300,000 in water damage to airplane or helicopter fuselage failures that involve loss of life and property.
What happened in the case study involving the Bell 206B helicopter crash?
-The helicopter experienced a loss of tail rotor authority, which caused the pilot to perform an emergency auto-rotation landing. While the pilot survived, the helicopter was destroyed.
What was the cause of the helicopter crash as determined by the investigation?
-The cause of the helicopter crash was the failure of the tail rotor drive quill, which stopped functioning properly due to sub-optimal lubrication, leading to overheating and material breakdown.
Why did the investigation focus on the maintenance of the tail rotor drive quill?
-The investigation focused on the maintenance because the quill had been recently serviced, and the incorrect placement of the cork during maintenance was suspected to have led to insufficient lubrication.
What defense did the maintenance firm present in the helicopter case?
-The maintenance firm argued that the helicopter flew for a significant time before the accident, which they claimed proved that the cork placement was correct and that the crash moved the cork.
What was the outcome of the legal case for the helicopter crash?
-The client of Elvis Tepush was awarded full compensation, including helicopter replacement costs, loss of business income, expert fees, and interest, as the judge ruled that the investigation should have ended much earlier.
What is the broader value of forensic engineering according to Elvis Tepush?
-Forensic engineering provides answers to those affected by failures and helps prevent future incidents by influencing changes in policies, manufacturing processes, inspection criteria, and material requirements, leading to fewer losses, injuries, deaths, and lower insurance costs.

Outlines

00:00

🔍 Forensic Engineering and Case Study Overview

Elvis Tepush, a forensic engineer at RJ Watering Company with a background in mechanical engineering and a PhD from UBC, discusses his work in determining the causes of various material, machine, and system failures. His team investigates a wide range of failures, from minor plumbing issues causing significant water damage to large-scale aviation disasters involving loss of life and property. The goal is to understand the underlying causes of these failures through thorough investigation. One example he provides is the crash of a Bell 206B helicopter, where a loss of tail rotor authority caused the helicopter to crash. Fortunately, the pilot survived, but the helicopter was destroyed, prompting an insurance investigation to determine liability.

05:17

🛠 Tail Rotor Drive Quill Failure: Cause and Legal Implications

The failure in the helicopter crash was attributed to the tail rotor drive quill, which was not properly lubricated due to the misplacement of a cork. This led to overheating and the eventual breakdown of the rotor's components. The investigation revealed that a maintenance firm had recently serviced the helicopter, and suspicion fell on them for improper maintenance. The firm argued that the helicopter's continued flight indicated the cork was correctly placed, but the accident damage prevented a conclusive determination. In the end, the client's claim was successful, covering helicopter replacement, lost business costs, and expert fees.

Mindmap

Keywords

💡Forensic Engineering

Forensic engineering is the investigation of materials, products, structures, or components that fail, causing personal injury, damage to property, or financial loss. In the video, forensic engineering is the field in which the speaker works, helping to determine the root cause of mechanical or material failures. An example is the investigation of a helicopter crash to understand the failure of the tail rotor.

💡Tail Rotor Drive Quill

The tail rotor drive quill is a component in helicopters that transfers power from the main gearbox to the tail rotor, enabling control of the helicopter's direction. In the case study discussed, the failure of this component due to improper lubrication was the main cause of a helicopter crash. Its breakdown illustrates the importance of mechanical precision in aviation safety.

💡Failure Analysis

Failure analysis is the process of examining why and how something failed, especially in technical systems. The video focuses on the speaker's role in investigating various failures, from small plumbing components to large aircraft fuselages, to determine the cause and prevent future incidents. This process often involves meticulous examination of the materials and design involved in the failure.

💡Lubrication

Lubrication refers to the process of reducing friction between surfaces in contact, which is essential in mechanical systems to prevent overheating and wear. In the helicopter crash case study, the tail rotor drive quill was not properly lubricated, leading to overheating and eventual failure. This highlights the critical role lubrication plays in the longevity and safety of mechanical components.

💡Auto Rotation

Auto rotation is a state in which a helicopter can descend safely without engine power by using the airflow to rotate the rotor blades. In the case study, the pilot was able to execute an auto rotation after losing tail rotor control, which helped avoid fatal consequences. This technique is an emergency procedure in aviation when mechanical failures occur.

💡Segregation

Segregation refers to the legal process where one insurance company seeks compensation from another after paying out a claim. In the video, after the helicopter crash, the insurance company pursued segregation to recover their payout, aiming to prove that improper maintenance caused the failure. This concept ties litigation into forensic engineering, where the determination of fault can influence financial liability.

💡Metallurgical Properties

Metallurgical properties refer to the characteristics of metals, including how they react to stress, temperature, and environmental conditions. In the case study, the improper lubrication caused overheating, which led to the breakdown of the metallurgical properties of the tail rotor drive quill, resulting in its failure. Understanding these properties is crucial in forensic engineering to explain why a material may have failed.

💡Maintenance

Maintenance involves routine checks, repairs, and replacements of parts to ensure that a machine or system continues to function correctly. The video emphasizes the role of maintenance in preventing mechanical failures, as in the helicopter crash where improper maintenance was found to be the cause of the tail rotor drive quill’s failure. Proper maintenance is essential to avoid such critical failures.

💡Litigation

Litigation refers to the process of taking legal action, often involving disputes over responsibility in accidents or failures. In the video, litigation was a major part of the helicopter crash investigation, where forensic engineering evidence was used to determine liability and recover costs through legal channels. This shows how technical investigations can have significant legal and financial implications.

💡Accident Investigation

Accident investigation is the process of analyzing incidents involving damage or injury to understand the causes and prevent future occurrences. The speaker explains how forensic engineers investigate accidents like the helicopter crash to identify failures in materials or maintenance. The results of these investigations can lead to changes in safety protocols and regulations.

Highlights

Elvis Tepush introduces himself as a forensic engineer at RJ Watering Company, with a background in mechanical engineering and a PhD from UBC.

Forensic engineering at RJ Watering Company focuses on determining the causes of failures in materials, machines, designs, and processes.

The scope of work includes failures from small components like plumbing parts to large systems like airplane fuselages, which can involve both property damage and loss of life.

Elvis highlights a case study involving a Bell 206B helicopter crash, where the pilot experienced a loss of tail rotor authority but survived due to proper altitude for auto-rotation.

The focus of the investigation was on the helicopter's tail rotor drive quill, which was determined to have separated, leading to the crash.

A key discovery was that the tail rotor drive quill was not optimally lubricated due to a misplaced cork, leading to overheating and eventual failure.

The breakdown of the quill's lubrication and material properties caused overheating, softening, and ultimate failure, resulting in the helicopter accident.

The investigation found that a maintenance firm had worked on the tail rotor drive quill shortly before the accident, raising questions about its role in the failure.

One defense from the maintenance firm was that the helicopter flew for a significant period before the accident, suggesting the cork placement was correct before the crash.

Despite this defense, the judge ruled in favor of the plaintiff, awarding replacement costs, business interruption losses, and even interest due to delays in settling the case.

Elvis notes that this case was unusual because the court awarded all requested damages, an uncommon outcome in litigation.

The forensic investigation revealed the failure early on, yet the opposing side prolonged the case unnecessarily.

Forensic engineering often deals with uncertainty, as investigators have only one opportunity to examine the failure evidence and cannot repeat accidents.

Elvis stresses that the value of forensic engineering lies in providing answers to those affected by material or machine failures, whether personally or financially.

Understanding failure mechanisms can lead to changes in policies, manufacturing processes, and inspection criteria, reducing future accidents, injuries, and insurance costs.