In general, Bill Ross, VP of Product Support for Superior Air Parts, described aircraft engines as “bulletproof.”
“When you look at the aircraft engine, you're talking about many engineering hurdles that have been overcome. So, it has to be small package, it has to be lightweight, it has to be good-looking, it has to be powerful, and it has to go to the TBO [time between overhauls] without any problems,” Ross said.
In fact, if the engine is maintained well, there should be minimal issues – and that’s the caveat: maintaining.
“Issues that can arise are those issues that are precipitated by neglect, or the lack thereof, as far as doing items of recommended maintenance,” said Ross.
Commonly Neglected
Ross said what he finds most overlooked for engines are the ignition system and fuel system calibration.
“What I mean by that is, the manufacturers of ignition systems and the engines have specific intervals for which inspections and/or overhaul should be completed,” said Ross.
He explained that pilots and mechanics can get complacent. If they go down the runway and do a magneto check and they don't have more than a 150 RPM drop, or 125 RPM drop and a 50 differential, they think they’re good to go.
But that cannot predict things lurking inside the magneto that can cause problems, Ross continued. “That would be something like carbon tracking, a dirty magneto, a broken distributor gear.”
These types of neglects can lead to pre-ignition events. Ross pointed out a catastrophic engine failure can be the result of lack of magneto maintenance.
“I'm not talking about, hey, the spark quit sparking and all. What I'm talking about is, the spark is not firing at the right time because its carbon tracking or the distributor gear is broken and it's just firing on one cylinder or something like that,” he said, noting that can lead to pre-ignition, detonation events, burn holes in pistons and cause oil starvation events.
Without performing the recommended maintenance, issues can go unnoticed until the catastrophic happens. Ross cites how some maintenance providers like to perform a “lean of peak” magneto check as a substitute, which can give an indication of health of the magneto or ignition system, but is still should not be a replacement for those recommended items of maintenance and inspection.
“I don't think that you can use it as a predictor of some type of failure that could be a bad issue,” Ross said. “You can go down to the end of the runway and you may have a fine mag check and then you go and fly, and you may have an issue.”
The issue, for instance, could be carbon tracking or imminent failure of a cracked gear.
Maybe carbon tracking or you may have – because an inspection wasn't performed – you couldn't see the imminent failure of a cracked gear or something like that,”
Ross said even fuel system calibrations, if not done correctly, can lead to fuel system problems, particularly in turbocharged engines, where they’re so lean that during high power settings on a hot day, they may get into a situation where they could detonate the engine.
“So when I'm talking about performing these items of maintenance, and this is not Bill's opinion, this is all predicated on good engineering data and testing and best practices,” he continued.
The Cause and Worth of the Neglected
No one wants to end up with a broken engine. The leading cause of neglected engines is save time and money.
“Everybody's looking for a way to save money. I'm an aircraft owner myself, believe me, I know what it costs to operate an airplane. And I think a lot of times, owners are misconstrued with, I can save on this item of maintenance and in the long run I'm going to be fine with that. That's far from the truth,” Ross said.
The cost associated with an event can be far greater than what’s saved by skipping on maintenance.
“If I skimp on an item of maintenance and then I have the unfortunate event of, for example, a detonation event and I damage the engine, burning a hole in the piston, I could do consequential damage to the engine, which renders the crankshaft no good, the cam no good, the connecting rods no good. And as an owner, if I have to start purchasing those things at overhaul time, overhaul becomes very, very expensive compared to an engine that was maintained well over the course of its life,” Ross said.
And worse, if an event were to happen while the aircraft is flying, Ross asks what does it cost to go get the airplane out of the field or out of the top of a pine tree?
“Or Lord, if you hurt somebody or you damage the airplane, what are the costs involved in those?” He continued. “And so, when we're talking about doing the right thing and reducing costs to the TBO, we need to follow those recommendations set forth by the people who design the product and want you to do what's best.”
Sometimes, neglect isn’t a direct cause of penny pinching, it stems from a lackadaisical attitude toward the need for this maintenance developed either as a result of bad habits or from seeing OEM recommendations as “busy work.”
“People start to take a lackadaisical attitude and an attitude that the OEM or the manufacturer is making busy work. And we're not in the business of making busy work. We want our customers at Superior, we want them to be safe, we want them to be informed, we want them to do the items of maintenance. We want their engine to go to TBO and beyond without ever having any issues. When we circumvent these things, we get the attitude that, oh, what do they know? They only did the design and the engineering and the endurance testing and all that, what do they know? I get a little scared because we can open up Pandora's box for a lot of problems,” Ross said.
Advocating for Maintenance
For mechanics, it’s pretty simple what needs to be done to keep engines healthy – follow the OEM guidelines. And while that might be obvious to maintenance professionals, they may need to convince aircraft owners of the importance, notes Ross.
“If the owner has questions, brings articles to the mechanic that says, oh, you really don't need to do that. I think that collectively, the mechanic and the owner can call the manufacturer, respected manufacturer, and discuss why? What is the premise behind this and why does this have to be done? So that the owner understands, too, how critical some of these things can be and how in the end game, they're not saving a dime, they're not saving anything at all,” he said.
If there's a service document that suggests that they perform something, Ross recommends that mechanics should research it and be ready to talk to owners and operators about it.
“We as aviation professionals, A&Ps, IAs, we need to make sure that we're doing what the manufacturer says from a liability point of view. We don't want to cut corners. And I think every mechanic out there should look at an A&P or an IA as a license to learn,” Ross added.
With that in mind, when speaking to pilots, Ross tells them to look at the resume of their mechanic.
“How much time do they have an experience on your particular product? And if you like the guy and he worked for American for 45 years or whatever, maybe he needs to go to the Continental school or to the Lycoming school or to Superior school, or go to some type of training where maybe there are some technical data that they need to subscribe to. You as the owner will be money in the bank to provide that for him. Because the mechanic's up against the rock and a hard place too with regards to costs,” he said.
Ross said he advocates that the mechanics and the owners communicate and develop an effective relationship between them so they can understand why they should be moving toward doing the recommendations set forth by the manufacturer to maintain the aircraft.
“You’re maintaining the aircraft in this constant state of readiness and you're doing the best thing that you can do. You're doing all that you can do to prevent problems,” said Ross.
