Preventative maintenance is in many ways a self-explanatory concept — prevent damage or repair what’s there to stop it from getting worse. The Federal Aviation Administration (FAA) defines it merely as, “simple or minor preservation operations and the replacement of small standard parts not involving complex assembly operations.”
However, the on-the-face simplicity of this kind of work obfuscates the intricacies and cruciality of it. Thanks to the COVID-19 pandemic’s ebbs and flows, scheduled maintenance needs to be thought of ahead of schedule. New technology is allowing for maintenance to be done and thought of in new ways à la sensors and “smart” technology. And that’s just naming a few of the complexities behind preventative aircraft maintenance.
You can see where that leaves things open-ended as to what is and what is not preventive maintenance,” said Frank Logsdon, Textron technical representative, Duncan Aviation, about the FAA’s definition.
“When applied to aviation, it [preventative maintenance] can be the difference between a small amount of time and materials to repair or prevent small problems, or an aircraft crashing and potentially killing people,” added Steve Goede, general manager, West Star Aviation. “What this means is taking care of things before they can become a much larger, more expensive, or potentially fatal problem.”
Mike Saathoff, director of sales opperations & engine and accessory sales, Elliott Aviation, estimates that 95 percent of the aircraft maintenance can be classified as preventative.
“I look at all inspections as being preventative. We’re doing inspections on aircraft to discover any discrepancies or any issues that could cause issues in the future. So those inspections are done at a particular time to be ahead of the situation to make sure you’re not running into any situations where something would break or be broken,” Saathoff said.
Goede lists the common types of preventative maintenance as:
- Lubrication of components
- Application of corrosion preventing chemicals
- Removal of corrosion from aircraft structure
- Replacement of worn or broken parts
- Cleaning aircraft structure and skins
- Repair and overhaul of aircraft components
Broadly, this work will be taken care of during inspections.
“There’s inspection programs that the engineers and manufacturers have put together. They are either time-based, like on a calendar, or usage-based, like with flight hours,” said Logsdon.
“The majority of the manufacturers have done a ton of studies ahead of time so that items are being inspected and replaced prior to a failure rate. A lot of overhaul and replacement items are what a customer would probably consider preventative,” added Saathoff.
Saathoff gives the example of many turboprop and similar aircraft having thousand-hour requirements. At a thousand hours, their generators come off and get overhauled back to manufacturers' standards, with the hope they run for another thousand hours.
“All aircraft are going to have their specific requirements based on their chapter four and chapter five requirements to their maintenance manual. Air worthiness standards to keep them legal and flying are all things that are put in place for the safety and the best operation of that airplane,” he continued.
Not Without Its Challenges
While scheduled inspections and flight hour-based work give preventative maintenance a backbone of support, again, what may seem like straightforward work is not always so. Saathoff said a “if it’s not broke, why fix it?” mentality among an aircraft owner can often be an issue.
“Preventative maintenance is sometimes difficult for an owner or operator to want to do. Because in some situations, it’s not broke right now. Or it’s not failing right now, it’s currently working. And so, some operators may resist the urge to, or may resist wanting to do that work now,” he said.
Saathoff said imparting the knowledge of why preventative maintenance is so crucial can be the greatest obstacle.
“The maintenance manual requirements were put in place to take care of them and make sure they’re safe,” he continued.
Currently, this issue is being compounded by an uptick in flyers excited to take back to the skies and reexplore the world as the COVID-19 appears to be subsiding. This is filling up hangars and pushing back work, meaning a pilot whose next scheduled maintenance is in two months should be getting on the phone to schedule that well in advance.
“With the way the industry has been, really, over the last six months, we’ve been trying to get further and further out with our customers to let them know, ‘Hey, you know what? We’re scheduled out into May. You’re going to want to schedule your work that’s due June and July now,’” Saathoff said.
Saathoff said work is at the highest he’s seen in 25 years and anticipates it to remain that way for some time due to the pandemic’s effects and a lack of technicians.
“People used to be able to call us, or in years past, would be able to call us and say, ‘Hey, I have work coming up in weeks.’ Right now, that may not be soon enough to get on the schedule. You may end up missing flights or not being able to get into the service center you wanted to get into if you don’t plan further ahead,” he said.
Goede echoed Saathoff’s assessments, agreeing that their greatest challenge as of now is finding the staff to do the maintenance.
“The largest problem facing aircraft maintenance at this time is the lack of experienced technicians. We have seen the number of experienced technicians dwindle over the past decade, as experienced technicians retire. These veterans of the trade are being back-filled with newly certified technicians who require years of training,” Goede said.
Then there is the matter of having the right parts; logistics is one of the largest challenges faced when performing preventive maintenance.
“This has always been challenging, but with COVID-19, these challenges grew even more. Suppliers have faced workforce shortages and shipping companies continue to struggle due to workforce shortages and high volume. This has led to increased downtime for maintenance and parts shortages,” Goede said.
For Logsdon, he cites one of the major challenges as being complacency – particularly when it comes to cleaning an aircraft.
“I can’t overstress the importance of just keeping the aircraft clean. And, mostly, technicians got into this field because they’re problem solvers and they like to fix something or see an actual solution, have some visual progress or some visual satisfaction for something that they’ve done. And wiping down the airplane and keeping the tires up to pressure is not really that satisfying.
“So I think that would be our biggest obstacle of the technician as far as preventive maintenance, is really putting the value on it that needs to be there. You could save so much by just doing the simple things now, possibly save people’s lives,” he said.
Clean Planes
Wiping down and cleaning planes is one of the simplest and most effective forms of preventative maintenance, but, as Logsdon points out, it is often overlooked.
“Cleanliness I can’t stress enough, as much as we’re seeing corrosion more and more these days. Keeping the aircraft clean and making sure that the paint and the sealant don’t have any voids or missing sections of them where water can ingress and cause corrosion. That’s huge,” he continues.
Cleaning an aircraft, unlike other preventive maintenance is often not a scheduled task. It slips people’s minds unless they’re visually seeing the buildup of debris.
“It’s something that you should see. You should take pride in your aircraft and make sure that you’re keeping it up to the best of your abilities as the manufacturer designed it,” he said.
This can be doubly important depending on where and in what conditions the plane is being flown.
“If you’re by the coastline, obviously, you need to clean the aircraft more, be more vigilant. Or if it’s flown through inclement weather, is a good time to really pay attention,” Logsdon said.
Technologic Overhaul
The largest cause for change to preventive maintenance is the constant re-evaluation of maintenance programs and the regulations that govern them, notes Goede, but adds that advancing technology is also driving changes.
“Aviation is a constantly changing industry, which has necessitated preventive maintenance to evolve as technology advances and better methods are developed,” he said.
Saathoff agrees and added that while on the mechanical side much of the technology is still that of the '80s and '90s, engines and avionics systems are allowing for greater tracking technology to be implemented. He notes that CAMP systems and other tracking technology utilized by aircraft owners is now able to be shared with them so they too can remind pilots of maintenance.
“A lot of customers will share their maintenance tracking system with us, give us access to their CAMP systems. We’ll stay ahead of it and give them a call and say, ‘Hey, it looks like two months from now you have this coming due. Based on your current usage of the airplane, you should probably be starting to schedule that work,’” he said. “They’ve gotten really good at what they do and being able to track those things and issue and offer reports to customers so they know when they should be scheduling their work and when they should be getting in with an MRO like us and getting the work scheduled."
Logsdon adds that they perform similar data collection with customers.
“We do downloads that show engine trend monitoring over the last several months. They’ll track the performance of the aircraft, engines, the ITT, the fuel flow, all the parameters that give them an idea of the degradation of the engine. That would be the biggest software that I use,” he continued.
And the more advanced aircraft in recent years are coming equipped with greater and greater data collection and monitoring services.
“They can do them in real time on the screen in the cockpit, or be transmitted back to the manufacturer either during inflight or when the aircraft is in the hangar. When it hooks up to the customer’s Wi-Fi, that information can be transmitted for real-time analysis. But a lot of operators find it a little cost inhibitive, because it’s running off a satellite phone and that bill can get quite large when you’re transmitting all that data,” said Logsdon.
Preventive maintenance will continue to evolve with technology and the changing work force,” adds Goede.
“Newer generations are entering the field, bringing with them a greater understanding of the newer technology. The constant improvement of the inspection processes will result in aviation growing and continuing to be a safe and efficient mode of travel,” he said.
Walker Jaroch is the editor of Aircraft Maintenance Technology.
