A&P’s are born with an itch to take things apart. That’s what drew us to aircraft maintenance in the first place. Airplanes are very cool and complicated machines, and it’s hard to resist the temptation to disassemble and dissect them to learn how they work. Putting them back together again is almost as satisfying. Almost.
I’ve long been struck by the close parallels between aircraft maintenance and medicine. Both doctors and mechanics devote themselves to troubleshooting and repair of extremely complex machines, and their work involves life-or-death consequences. Doctors, however, are bound to the Hippocratic oath to “first, do no harm.” A&P’s don’t take such a pledge. Maybe we should.
Because the truth is that the more we wrench on airplanes, the more risk we introduce. We’ve known this since the early 1940s and the work of Dr. C.H. Waddington with theRAF Coastal Command (“the Waddington effect”) and rediscovered it in the late 1960’s with the work of Stan Nowlan and Howard Heap at United Airlines (“Reliability-Centered Maintenance”). Recent research by Scarpazza and Hutter (“QuantifyingMaintenance Risk”) suggesting that small GA airplanes are at greatly increased risk of mechanical failure during the first 30 hours or so after their last inspection.
SAVVY FOR SHOPS
The world of maintenance for small GA airplanes is still stuck in the 1950s. Most GA shops and mechanics operate with the same philosophy and habits they did in the Eisenhower era: pull cylinders for weak compression, overhaul engines and props at arbitrary TBOs, and treat manufacturer maintenance schedules as if they were handed down on stone tablets.
Meanwhile, airlines, the military, and big bizjets have moved on, adopting modern maintenance philosophies built on data-driven diagnosis, on-condition preventive maintenance, and minimally invasive inspection and repair techniques. They endeavor todo just enough maintenance to make the aircraft safe and reliable, understanding that doing too much maintenance can be worse than not doing enough.
Small GA has been left behind. That’s why we created Savvy for Shops, our new initiative to help drag general aviation maintenance kicking and screaming into the 21st century. It’s a three-pronged effort.
First, there’s ShopTalk, our free online community for GA mechanics to share ideas, problems, solutions, opinions, sources of parts, employment opportunities, and hangar wisdom with one another. Savvy has had this kind of in-house chat room for more than a decade where our team of 40+veteran IAs, analysts and subject matter specialists ask questions, request second opinions get trouble shooting ideas, and create team cohesiveness. With the launch of ShopTalk, we have expanded this online inner-circle to participation by GA maintenance professionals, trainees and students worldwide. Career aircraft mechanics are welcome to join the group at community. savvyaviation.com.
Second, there’s a new consulting service for shops that we call Powered by Savvy. It gives participating shops access to Savvy’s brain trust of veteran IAs, analysts, engine builders, avionics technicians, and other subject matter specialists, and is modeled after Savvy’s highly successful SavvyQA consulting program for aircraft owners. It’s like having a roomful of graybeard maintenance experts on speed dial.
SAVVY CERTIFIED TRAINING
Third, and perhaps most important, there’s Savvy Certified AMT Training, our new online course for A&Ps and IAs, aimed at teaching both graybeard mechanics and newbies the latest methods and best practices for doing maintenance like the big boys.
IAs are required to meet certain FAA requirements each year in order to maintain their Inspection Authorizations. They can do a certain number of inspections, major repairs or alterations. However, most choose to take eight hours of IA refresher training each year, similar to how doctors take CME each year to maintain their board certifications. Nowadays, most IAs take this training online from one of a handful of providers.
So, we figured if IAs have to take eight hours of annual training, they might as well spend the time learning something new, rather than just the same ol’ same ol’. Learning stuff that could actually make them better mechanics, and do more good and less harm to their customers’ aircraft.
That’s the idea behind Savvy Certified AMT Training. It’s free and online, accessible from any device—even a smartphone—and it’s FAA-blessed for IA renewal credit. I think it’s far and away the most professional, highest quality, most educational, enlightening and valuable online AMT training ever. (I’m biased.)
The course presently consists of eight hour-long modules, each consisting of a series of video training segments interspersed with short quizzes and ending with a final exam. The quizzes and exams are learning opportunities, not assessments, allowing wrong answers to be corrected.
THE RULES OF THE GAME
Every FAA-accepted IA renewal course needs to cover the regulations related to maintenance. There are roughly 30 rules that every maintainer needs to be familiar with.The first hour of the course focuses mostly on the Part 91 rules that speak to aircraft owners, and the second hour on the Part 43 and 65 rules that speak to maintainers.
However, most of these first two hours is spent telling “the rest of the story.” Why are these regs worded the way they are? What do they really mean? How are their meanings affected by FAA policies and legal interpretations?For instance, what exactly is“preventive maintenance” in light of the 2009 Coleal interpretation? What exactly does it mean for a maintenance method, technique or practice to be “acceptable to the Administrator”? What exactly does “airworthy” mean? Stuff like that.
Perhaps most importantly, this section of the course explains the division of responsibility and authority between aircraft owners and mechanics. It discusses the essential partnership between owners and maintainers, what causes this partnership to go off the rails sometimes, and how to ensure it works as smoothly as possible
RELIABILITY-CENTERED MAINTENANCE
Hour 3 is devoted to Reliability-Centered Maintenance (RCM), the science of how to do just enough maintenance to make an aircraft safe, reliable and legal, while not doing so much that it degrade safety through maintenance-induced failures. RCM was first developed in the late 1960s at United Airlines, where it turned traditional thinking about maintenance on its head. United scientists Stan Nowlan and Howard Heap discovered that very few mechanical failures happen because components became old and worn out. Instead, the lion’s share of failures are “infant mortality” occurring when components are young, not old, or when systems that are working fine are messed with unnecessarily.
The implications of this discovery were cataclysmic. It means that the traditional practice of overhauling components at a fixed TBO or replacing them at a fixed life limit actually makes the aircraft less safe and reliable. Also that taking things apart to inspect them on a fixed timetable often does more harm than good. RCM researchers amassed a huge body of evidence proving that “if it ain’t broke, don’t fix it.”
Unfortunately, much of the scheduled maintenance called for by most manufacturers turns out to be more like “if it ain’t broke, fix it until it is.” Fortunately, the FAA doesn’t require us to follow most of this dumb guidance, and we shouldn’t.
MINIMALLY-INVASIVE METHODS
The next two hours provide detailed “how-to” instructions for some of the most important modern minimally invasive methods for cylinder inspection and repair. The traditional standard of care is to do a compression test at each annual inspection, and cylinders exhibiting weak compression are removed and sent out for repair or overhaul. This is the equivalent of checking a patient’s heart with a stethoscope and performing open heart surgery if an arrhythmia is detected. Cylinder removal is both maximally invasive and unnecessarily risky.
Surgeons used to cut patients open for exploratory surgery. Now they use ultrasound, CT scans, MRIs, catheters, endoscopes, laparoscopes, and all sorts of other minimally invasive tricks. General aviation maintenance, sadly, is still stuck in cut-the-patient-open mode. We need a paradigm shift.
In hour 4 of the course, we detail a pair of minimally invasive methods that address the two most common causes of weak compression. If the weak compression is due to leakage past the exhaust valve, lapping the valve in place will usually solve the leakage and dramatically improve compression readings. If the issue is leakage past the rings, a simple solvent ring flush can work wonders, freeing up stuck rings and reducing oil consumption and spark plug fouling. Both methods eliminate the need for cylinder removal.
Hour 5 teaches an important skill that isn’t covered in A&P school: how to perform a proper borescope inspection of a cylinder. It describes the 11 images that need to be captured in a specific order for each cylinder, and demonstrates exactly how to position the scope to obtain each one. It shows how these images can be uploaded to Savvy’s cloud-based image repository, tagged, analyzed, annotated, archived, and reported.
DATA-DRIVEN TROUBLESHOOTING
The last three hours of the course are devoted to troubleshooting, the special aspect of aircraft maintenance that is accomplished purely with headwork, not handwork. Working with hundreds of shops and thousands of mechanics over the past 17 years, we’ve found that troubleshooting is one of the weakest areas for most A&Ps. Some A&Ps are troubleshooting superstars, but they’re few and far between. We need to do a lot better.
When faced with an aircraft system that isn’t working properly, the urge to find out what’s wrong by taking it apart can be powerful. Mechanics need to resist that urge. The key to diagnosing a problem accurately is to gather as much data as possible, preferably by non-invasive means. This is best accomplished using tools like borescopes, multi-meters, lab reports and engine monitor data—not wrenches, screwdrivers, and other implements of destruction.
Hour 6 of the course covers basic troubleshooting theory. It takes a deep dive into the methodology of “differential diagnosis” that every doctor is taught to use in med school but few mechanics are taught in A&P school. In a nutshell, this involves making a list of everything that could possibly be wrong with the malfunctioning component or system, then go through the list and ruling out any possible causes that are inconsistent with the symptoms and diagnostic data. With luck, only one possible cause will survive, and that’s the definitive diagnosis. If more than one possibility remains, then additional tests are performed and data gathered in order to rule various possible causes in or out. This module offers numerous examples of how this differential diagnosis method is used to troubleshoot real-world aircraft issues.
Hour 7 dives into the analysis of digital engine monitor data, one of the most powerful tools we have for diagnosing engine problems. The power comes from engine monitor data analysis uniquely showing in exquisite detail what the engine is doing when it’s actually running. It is totally non-invasive. This is a skill that is not taught in A&P school, and is hardly ever utilized by mechanics in the field. We hope to change that.
Finally, Hour 8 offers a satchel full of tips and tricks for diagnosing common engine and electrical problems. Things like rough-running, hard starting, high CHTs and EGTs, low oil pressure, charging failures, high or low bus voltage, headset whine, circuit breaker trips, and more.
CHANGING THE CULTURE
This new AMT training course isn’t just about state-of-the-art methods—it’s about culture. For too long, GA maintenance has been mired in tradition, habit, and a blind faith in OEM guidance. Our hope is that Savvy Certified mechanics and shops will adhere to a higher standard—one built on evidence, data, and techniques that minimize risk and cost while keeping aircraft safe, reliable and legal. If you’re an IA, please give serious consideration to taking this training—it’ll change your perspective.
If you’re an A&P or trainee, you’ll get a lot from this training and your name on the Savvy Certified wall of fame. If you’re a maintenance-involved aircraft owner, it’ll help you keep up your end of the owner-mechanic partnership. If you’re one who would rather not think about maintenance, try to persuade your IA to take the course.