Pratt & Whitney's operational fleet includes some 11,000 commercial engines and approximately 7,200 military engines. Multiply that by the number of parts in a jet engine and the ability, and necessity, for the company to monitor each engine's parts throughout their life cycles become even more impressive.
"A lot of employees, including the flight safety office, field representatives, customer support engineers and technical leads, track our military and commercial engines daily to ensure safety of flight," said Mike Millat, operational safety risk analyst, F100 safety lead and V2500 safety review facilitator, Engineering Product Integrity. "This generally comes from examining field data in different formats. Potential concerns can range from maintenance finds, design reviews, quality concerns or events."
Millat knows firsthand how critical the integrity of every Pratt & Whitney engine part is as he piloted U.S. Air Force C-17s for eight years before joining the company two years ago.
"Pilots generally are very process- and checklist-oriented, and I use those skills every day," he said. "Given my background, I tend to look at everything from a human factors perspective. We deal with highly technical issues here but, ultimately, it all comes back to people – a pilot, an engineer, a passenger. I'm constantly thinking about what we can do from a process standpoint to design and maintain our engines so that we prevent issues before they occur."
Data collection and analysis is critical to flight safety assurance. "If there's a potential safety concern we conduct a robust root-cause investigation and collect a lot of data for quantitative analysis to determine whether chances are remote or likely for an event to happen," Millat said. "Even if action ultimately needs to occur in the form of inspections or a redesign, we continue to track that fix to ensure field safety. For parts that don't need action, we watch and monitor them, sometimes for years, to ensure that they are behaving as predicted."
Paul Smith, chief engineer, Commercial Engine Programs, V2500 and PW4000, added that during the design phase IPT teams develop FMEAs (Failure Mode and Effects Analysis) for each part and system.
"However, as we go through development we add to our understanding of the effects of failures," he said. "Even 30 years into service, we occasionally still have new learnings on those effects. We need to think of our FMEAs as living documents to be updated each time we have a new learning."
For the company's military engines, understanding the implications of what needs to be done, both in terms of safety and operational usage, can be particularly critical. "Our military customers can be using our engines in active combat at any given time and need to be satisfied both with our engines' performance and their reliability," said Ron Fritsch, chief engineer, Operational Military Engines. "They can't afford to have aircraft on the ground when it's a life or death matter. Our being able to understand this and provide a program that ensures our engines are available and safe is crucial."
Legacy engines can present their own set of issues. "If you have a program that's been operational for 30-plus years and it has an issue you've never seen before, you have to conduct extensive analysis to determine if it's a one-off or something more systemic," Millat said. "We're constantly answering those sorts of questions. The process involves managing and interpreting mountains of data, which can be complicated but critical to ensuring we manage any potential safety concerns effectively."
While balance, priority and resources may vary depending on the criticality of any given safety issue, one thing is not open to debate. "Safety is at the top of our company's priorities," Fritsch said. "For us, it's safety first, all the time."
"If you don't focus first and foremost on safety, including pursuing all potential safety issues, you won't have to worry about the rest of our business metrics because you won't have customers," Smith added. "It's a non-starter."