Mike Busch

How to destroy your engine in one minute

April 13th, 2015 by Mike Busch

At least once a year for as long as I can remember, I have been contacted by an aircraft owner whose piston aircraft engine was destroyed or severely damaged by a destructive detonation or pre-ignition event. In one recent 12-month period, I encountered three such incidents.

One incident involved British Cirrus SR-20 powered by a 200 horsepower Continental IO-360-ES engine. The plane was equipped with an Avidyne Entegra MFD with an integrated engine monitoring system called “EMAX.”

The CHT data downloaded from the EMAX system tells the short story of this engine’s demise:

SR-20 pre-ignition event

Click on image to open a higher-resolution version.

Everything looked fine until about two minutes after the pilot applied takeoff power, at which point the #1 cylinder’s CHT began to climb rapidly compared to the other five cylinders. At the three-minute mark after brake release—with the aircraft at roughly 2,000’ AGL—CHT #1 rose above 400°F and set off a high-CHT alarm on the MFD.

CHT #1 continued its rapid rise—nearly 1°F per second—that continued unabated until the piston and cylinder head were destroyed approximately five minutes after takeoff power was applied and two minutes after the CHT alarm was displayed. At that point, since the cylinder was no longer capable of combustion, CHT #1 started plummeting.

We can’t be sure just how hot CHT #1 got because the Avidyne EMAX system “pegs” at 500°F. A reasonable guess is that the CHT peaked somewhere between 550°F and 600°F. No cylinder or piston can tolerate such conditions for very long, and this one obviously didn’t.


Not long after CHT #1 went off-scale on the MFD, the pilot realized something was very wrong, and pulled the power way back. But he was a couple of minutes late, and the engine was already toast. Here’s what the #1 piston looked like after the event:

Piston with corner melting

Click on image for higher-resolution version.

Note the melted corners of the piston crown, the destruction of the top compression ring lands, and the severe metal erosion above the piston pin. (Much of this molten metal wound up inside the crankcase and contaminated the bearings and oil passages.) Also note the severely hammered appearance of the piston crown, the classic signature of heavy detonation. The cylinder head was found to have a big chunk of metal missing from it. Both spark plugs were destroyed by the event as well.

This engine was a low-time Continental factory engine, so the owner figured that the severe engine damage would be covered under Continental’s warranty. I advised him not to bother filing a warranty claim, because I’ve never known Continental to give warranty consideration for a destructive detonation or pre-ignition event. Continental considers this to be operational abuse, not a defect in materials or workmanship, and therefore not covered by warranty. (For what it’s worth, I agree with Continental’s position on this.) The owner didn’t believe me and filed a warranty claim anyway. Continental promptly and unequivocally denied the claim, just as I predicted.

The moral of the story is that it is important for aircraft owners to have a good digital engine monitor installed, to know the telltale symptoms of destructive detonation and pre-ignition, and to act fast when those symptoms appear. You may have less than one minute to react if you want to save your engine.

Another incident

Here’s another similar case that occurred to a Beech Bonanza very shortly after takeoff. The annotated JPI data for this event is courtesy of General Aviation Modifications Inc. (GAMI):

Preignition event

Click on image for a higher-resolution version.

This time, it was the #5 cylinder that experienced thermal runaway and pre-ignition. It was an even more severe event than the one suffered by the Cirrus, and took only two minutes from the application of takeoff power to the complete destruction of the #5 piston, which wound up with a large hole melted through the piston crown:

Holed Piston

Click on image for a higher-resolution version.

Now that’s ugly!

In yet another case (for which I unfortunately have no photos), a drop-dead gorgeous Lancair IV-P kitplane powered by a fire-breathing 350-hp TCM TSIO-550 engine went up for its first test flight after 10 years of laborious building time by the owner. Within minutes, the airplane was back on the ground with an engine that was totally destroyed. A forensic post-flight evaluation revealed that the magnetos had been timed approximately 10 degrees advanced from the proper timing. That turned out to be a $50,000 mistake.

The Lancair’s instrument panel was wall-to-wall glass, including an ultra-sophisticated digital engine monitoring system. The engine monitor was literally crying out for attention throughout the short test flight, but the test pilot never noticed its warnings until the engine cratered.

What causes this?

There are a number of things that can cause or contribute destructive events like these. I’ve already mentioned one: advanced ignition timing. It’s astonishing how often we see engines with the magneto timing advanced several degrees from spec. (E.g., 25° BTDC when the engine data plate calls for 22° BTDC.) Even a couple of degrees is enough to significantly reduce the detonation margin of the engine. Add a hot day and perhaps a cooling baffle that isn’t quite up to snuff, and BOOM!

Owners should be particularly alert for mis-timed magnetos whenever maintenance is done that involves magneto removal or adjusting magneto timing. (More often than not, these occur during the annual inspection.) If mag timing is advanced, you’ll notice that your EGTs are lower and your CHTs are higher than what you were seeing prior to maintenance. (Retarded timing results in the opposite: higher EGTs and lower CHTs.) If you notice this after the airplane comes out of maintenance, take it back to the shop and have the mag timing re-checked. It’s a quick check and could save your engine (not to mention your gluteus maximus). Magnetos are required to be timed within one degree of the timing specified on the engine’s data plate, and any error should be in the retarded direction.

MP and FF guage comboAnother common culprit is inadequate fuel flow on takeoff. When taking off from a near-sea-level airport—or from any elevation if you’re flying a turbocharged airplane—you need to see fuel flow that’s right up against the red-line on the gauge (or the maximum fuel flow shown in the POH). Unlike most other gauges on your panel, hitting red-line on the fuel-flow gauge (or even going a smidgen over) is a good thing, not a bad thing. Takeoff fuel flow is a lot like tire pressure—a bit too much is a whole lot better than a bit too little. Anything less than red-line fuel flow on takeoff reduces the engine’s detonation margin, and significantly less can reduce it enough to cause a catastrophic event.

Not long ago, a client of my maintenance-management firm had a prop-strike incident that required a teardown inspection of the engine. When the inspection was complete and the engine was reinstalled in the airplane, the owner picked up the airplane from the engine shop and flew it back to his home base airport. Upon arriving there, he informed us that the fuel flow was 3 GPH below red-line on takeoff, and asked that we schedule a service appointment to have the fuel flow adjusted.

I was flabbergasted. What was this owner thinking? Why didn’t he abort the takeoff immediately when he noticed that the fuel flow was 3 GPH short, and ask the engine shop to adjust it? Why would he fly the airplane home in that condition? What part of “inadequate detonation margin” didn’t he understand?

Yet another cause is a partially clogged fuel injector nozzle. This can occur anytime, but most frequently occurs shortly after the aircraft comes out of maintenance because that’s the most likely time for foreign material to get into the fuel system. (I’ve had two serious clogged-nozzle episodes in my airplane over the past 25 years, and both occurred shortly after an annual inspection.)

Save your engine!

ThrottleRegardless of the cause, the solution is not rocket science. There are two simple rules that will almost always prevent these sorts of destructive events from occurring:

First, check your fuel flow gauge early on every takeoff roll. If the fuel flow is not at red-line or very close to it, reject the takeoff and sort things out on the ground. (The exception is takeoffs at high density altitudes in normally-aspirated airplanes, and detonation is quite unlikely under those conditions.)

Second, set your engine monitor CHT alarm to 400°F or less for Continental engines and 420°F or less for Lycoming engines. (On my own Continental-powered airplane, I have my alarm set to 390°F.) When the alarm goes off, do whatever it takes right now to bring the CHT back down below 400°F. Verify that the mixture is full-rich. Turn on the boost pump if it isn’t already on. Open the cowl flaps if you have them. And if CHT triggers the alarm and appears to be rising rapidly, throttle back aggressively to stop the thermal runaway. Don’t be shy about doing these things immediately, because you may only have a minute or two to act before your engine craters.

(Oh, and if your airplane isn’t equipped with a digital engine monitor with CHT alarm capability, do yourself a favor and install one. Trust me, it’ll pay for itself quickly.)

When you get on the ground, put the airplane in the shop and have the spark plugs removed and inspected for damage, the cylinders borescoped, and the magneto timing checked. If takeoff fuel flow was short of red-line, have it adjusted before further flight.

Jolie Lucas

When to get some Dual on the couch: mental and emotional health needs of pilots

April 6th, 2015 by Jolie Lucas
Take a breath, take an honest look

Take a breath, take an honest look

Recently I suffered three unexpected losses. I use the word suffered on purpose here. In December I needed to get a flight review. I had scheduled this with three instructors, but due to the holidays, I was unable to get it done. In early January I contacted a local CFI that I know only socially. He knew about the losses in my life. After talking with me a few moments, he gently suggested that I was not well enough emotionally to fly that day. Of course, I burst into tears because he was number four on my list of instructors.

After I got done crying about it, I got to thinking about how, as a professional psychotherapist, I was seemingly unable to see the state of my own mental health. Below is an excerpt of an article I wrote for AOPA Pilot as well as a link for online screening tools for depression, anxiety, bi-polar and PTSD.

Here are some simple ways to put you and your emotional health on the pre-flight checklist as well as some ideas on when to get support if needed.

Mood: Think back over the past week. Rate your mood on a 1 to 5 scale with 1 being the lowest, and 5 being a happy mood. What is your average? Has anyone told you that you look tired, depressed, or nervous? Sometimes our spouse or families are the greatest mirrors for us. We might not see our mood, but to them it is written all over our faces.

Sleep: Have you been sleeping well? The average person in a lab setting will sleep a 6-7 hour stretch and take a 1-2 hour nap in the afternoon. Think back and check whether you have had any difficulties falling or staying asleep. Our deep restorative delta sleep typically happens well into an uninterrupted sleep cycle. Think about performing a go-round on every approach, with sleep we simply cannot get down to delta if the cycle is continually disrupted.

Energy: Has your get up and go, got up and went? Do you find yourself drinking coffee or energy drinks just to get through the day? Some pilots find they have too much energy and are unable to relax into a healthy focus. Between the tortoise and the hare, somewhere in the middle of the two is the most efficient.

Anxiety and Worry: Someone once told me that worry is interest on a debt we don’t yet owe. An interesting study on worry shows that it can be healthy in small doses. Worry is a high brain function, one that can help us sort through possibilities and strategies. Too much worry shuts down the function and we can find ourselves in a lower brain: fight, flight, or freeze. 30 minutes of worry once per week is effective. How many minutes this week have you racked up?

Concentration/Focus: Particularly important in being pilot-in command [PIC] is the ability to concentrate and stay focused. If you are noticing that your mind is wandering or you are distracted by worry, it might be best to keep yourself and the aircraft on the ground.

Sex Drive: This might seem a strange item to have on your personal checklist, but the fact is a person’s sex drive can be indicative of emotional health. A lack of desire can be suggestive of a mood problem.

Appetite: Does your favorite food taste good to you? Are you eating for comfort or to excess? Healthy food is fuel for the brain and the body. Make sure that you do not fly without fuel on board.

Bumper Sticker: Ask yourself this question and pay attention to the answer: If you had to summarize your attitude about life to fit on a bumper sticker, what would yours say? Is your bumper sticker upbeat and optimistic, or doubtful and negative?

Below is a link for the Mental Health America online screening tools. These screening tools are for use with adults only. If your screening indicates a problem, it is best to contact a licensed mental health counselor in your community for follow-up.


A few days after my crying spell, I completed my flight review and had a great time doing it. My instructor had not flown in a Mooney for some time, and after the necessary maneuvers, I was able to show him a lot about my airplane.

Me and Dad, Christmas Eve

James and Jolie Lucas

One of my losses was the death of my father who was a primary flight instructor in the Army Air Corp and a Mooney pilot for 30 plus years. The day I was to leave for his memorial I was checking and double-checking the weather. I thought to myself, “I wonder if I am okay to fly?” That was the only question I needed to ask. If you wonder if you are okay, you are not okay. I packed up the car and made the five-hour drive with my son. While an hour and a half in the air is quicker, for me, that day, the drive was safer.

Our mental health is equally important as our physical health. We are all subject to the same rules of stress and loss. I am happy that CFI #3 told me he didn’t think I should be flying. His insight could have saved us from a bad outcome. I believe we all do need to have eyes and ears on our fellow pilots. We are a small community and we all get to do something that we love to do. Let’s all make sure we are up to the task emotionally too. Thanks for listening.


Amy Laboda

When the Answer is No

March 30th, 2015 by Amy Laboda

I did not go flying last weekend despite the gorgeous weather. Not even last week. It was not for want to do so. It was because I flunked a test.

What test can a pilot at my experience level flunk that could ground me? The FAA’s IMSAFE test, that’s what. The pithy mnemonic stands for:
Illness – Is the pilot suffering from any illness or symptom of an illness which might affect them in flight,
Medication – Is the pilot currently taking any drugs (prescription or over-the-counter),
Stress – Psychological or emotional factors which might affect the pilot’s performance,
Alcohol – What has the pilot consumed within the last 8 to 24 hours,
Fatigue – Has the pilot had sufficient sleep and rest in the recent past, and
Eating – Is the pilot sufficiently nourished?

It seems like a simple test that every pilot can perform, but it only works when we are honest about it (NTSB accident reports reveal that is sometimes not the case).

When I ran the test last week item #1 doomed me. I had a nasty case of the common cold. At first it was a tickle in my throat, then a burning in my ears that carried through each swallow. And then I woke up and I simply could not breathe through my nose, my chest ached and felt like I’d been left for dead by the side of the road. No fever. Just malaise. Ugh.

I had two “really want to go” flying trips and two that were flexible last week. I considered medication. I even went online to AOPA.org’s Online Medications database  and looked up the many possible medications that I might take to relieve my symptoms without risking the wrath of the FAA coming down upon me.

The database is extensive (although its disclaimer is quick to tell you it is neither guaranteed nor complete), and pinging it for “cures” to the common cold gave me a few ideas, even as it warned me off a few, too. For instance, who knew that heavily advertised Zyrtec is limited to two (2) weekly doses and a 48-hour waiting period post-dosing before flying? That was useless to me: the drug only works for 24 hours at a time. Nyquil was out, too, requiring a 60-hour wait before flight. The old standby Sudafed was in there, but not so easy to get (it sits behind the pharmacist’s counter these days).

In the end I stuck it out with Vick’s VapoRub, vitamin C and chicken soup. I succumbed to Nyquil a couple of nights, too, just to catch some healing winks.

Oh, and I did not fly, at least until the weekend, when I was beginning to feel better. I tested the air by asking my regular co-pilot to be PIC for me on a short, low-altitude journey. The leg out went fine, but the leg back? As we began to descend back to our home field I heard a crackling, and then one ear went muted.  It “hung” at 1,000 feet agl, even as my pilot deftly touched wheels to grass at home. The pressure hurt. Experiment results? Failure. I was not ready to be PIC, in fact I should not have gone up at all, even as a passenger.

One dose of decongestant brought the ear back to sea level and no permanent harm was done. My co-pilot turned-PIC flew off a couple of hours later to cover for me at my last obligation of the week. Sorry guys.

As I type this I am breathing easy and free again without medication, and I’m ready to give flight another try. This time, however, there is no doubt in my mind—IMSAFE today. Are you?

Rob Mark

Improving Your Stick and Rudder Skills: Seaplanes and Taildraggers

March 23rd, 2015 by Rob Mark
UPRT Photo

APS Training photo

In mid-January, the National Transportation Safety Board (NTSB) released some cold, hard facts. “Between 2001 and 2011, over 40 percent of fixed wing general aviation fatal accidents occurred because pilots lost control of their airplanes.” You might be surprised to learn that when The Boeing Company studied commercial jet accidents around the world between 2004 and 2013, the cause that resulted in more fatalities than any other – by a 2 to 1 margin actually – was Loss of Control Inflight (LOC-I). What we don’t know of course is why this keeps happening?

While the relationship between LOC-I precursors and actual loss of control is still being investigated, it’s clear that pilots of all categories are, at times, simply unable to fly their airplanes out of situations in which they find themselves. Cockpit automation has often been pegged as a likely culprit. Today, we’re going to do our part to slow the advance of LOC-I by turning off all the cockpit automation and hand-flying the airplane more often. Two ways I learned to be more closely tied to my airplane was to check out in a taildragger and earn my seaplane rating. Both require all hands on the controls from the moment you turn over the engine until shutdown. While flying both can be challenging at times, I’ve found the skills they build have truly made me a better pilot and instructor.

Dragging My Tail

I learned to fly a 7ECA Citabria many years ago after I bought it. I thought it was just an airplane with the steering wheel on the wrong end – although it used a control stick and not a wheel. Wrong again. For starters, the view out the cockpit window was different from the tricycle gear aircraft I’d flown Taildraggerbecause the taildragger’s nose sits high on the ground. That makes taxiing … interesting. Lots of rudder and brakes to turn the aircraft, or even keep it heading straight, especially when a strong breeze starts blowing. My first few hours with an instructor produced a great logbook entry … “N8300V 1.5 of crash and dash,” he wrote. I was mortified. After all, I already held a commercial pilot certificate. I’d pour the coals to it on takeoff and of course, with P-factor, torque and everything else, the Champ would head to the left side of the runway. Then I’d kick right rudder which brought us back toward centerline. Unfortunately, I waited until the nose began heading to the right edge of the runway to kick in left rudder and hence many zig-zag takeoffs were started and stopped. The key turned out to be calm days of partial power on takeoff, just enough so I could raise the tail and learn to steer before I pulled the throttle back and taxied back for another try.

It took me awhile to realize I needed to lead the nose around rather than allowing it to lead me. But of course during takeoff, the airplane is also trying to accelerate and I couldn’t see much over the nose. I also learned to raise the tail once there was enough airflow. But you have to do that gently or you’ll put the airplane on it’s nose. You might remember something in ground school called gyroscopic effect … well maybe not. Point is, when the tail comes up, that movement also makes the nose want to swing so you really need to be on the rudders there too … positively, but gently. During my first landings, all seemed normal until I realized this was simply a reverse crash and dash … keep on the rudders to keep the nose straight. Add a crosswind and it becomes a tad challenging until the tail comes back down.

Worst case scenario in my Champ was the inability of the airplane to turn downwind after landing in a 25-knot headwind. Too much brake and power and I could feel I’d put the thing on its nose. The solution turned out to be impossibly simple. Shut the engine down, get out and lift the tail myself to turn the airplane around. Then I restarted and moved it to my tiedown. While all of this sounds tough, after 10 hours or so, I was no longer zig zagging. I used my rudders often and cross winds no longer seemed to bother me as much. I’d become not only coordinated, but finely tuned.

seaplaneSplish Splash

Last fall I realized I craved a new learning challenge. That evolved into earning my seaplane rating in Traverse City, Michigan. The first hour in that Cub on floats reminded me of a few things from my days as a taildraggers student. When the pitch and power of the instructor’s voice is high and loud, danger is near. I also realized the airplane started moving the minute the propeller spun up and of course, there are no brakes. Like the Champ, the Cub had a control stick which I thought made aileron and elevator movements easier to plan and water rudders for improved steering on the surface. I just needed to remember to retract them before takeoff and landing. The seaplane rating is all about learning to taxi, takeoff and land on the water. The rest is like any other airplane, except that when the instructor pulled the engine on me at 1,000 feet AGL, those floats acted like barn doors that pegged the vertical speed indicator pretty fast. On takeoff, it’s all about finding a place on the water called, “the step.” It’s a spot where you have just enough forward pressure on the stick to raise the back of the floats out of the water, but not so much that you put the airplane on its nose. Like the taildragger, it was all about learning to fine tune my movements. I learned this piece of fine tuning the hard way however.

On takeoff, I shoved the stick forward in the Cub like I did to raise the tail in the Champ. WRONG! I learned that fine tuning means too much forward pressure on the stick and the floats bog down in the water. After a few takeoffs, I absolutely began to feel it. Too little back pressure on takeoff and we just mush along in the water like a boat. Finding the takeoff sweet spot meant power, a bit of forward pressure and after about three or four seconds, the airplane accelerated … no it actually jumped ahead. Then I had to finely oscillate the stick to keep the floats in the same place until liftoff speed. Then a bit of back pressure and I was climbing just like a regular bird. By the second hour or so of instruction I thought figured it out. My silent instructor in the back seat confirmed it. There is of course the issue of docking the airplane to contend with too, but I’m still working on that part.

The point of convincing you to give a taildragger or a seaplane rating a try is of course, both are fun. But both also require the pilot to control the aircraft very precisely at times. The first few hours will be real work, but after that you’ll be surprised at how much better you’ll fly these and any other airplane. BTW, when you see AOPA President Mark Baker at AirVenture this year, tell him you’re thinking about a seaplane rating. He has more great seaplane stories than any half dozen other pilots I know.

Mike Busch

Champion Aerospace: From Denial to Acceptance

March 19th, 2015 by Mike Busch

Champion Aviation Spark PlugsAccording to the model popularized by Dr. Elisabeth Kübler-Ross in her seminal 1969 book On Death & Dying, there are five stages of grief: denial, anger, bargaining, depression, and acceptance. This is apparently what Champion Aerospace LLC has been going through over the past six years with respect to the widely reported problems with the suppression resistors in its Champion-brand aviation spark plugs. I last discussed this issue in my August 2014 blog post Life on the Trailing Edge.

I first became aware of the Champion spark plug resistor problem in 2010, although there’s evidence that it dates back to 2008. We were seeing numerous cases of Champion spark plugs that were causing bad mag drops, rough running and hard starting even though they looked fine and their electrodes weren’t worn anywhere near the retirement threshold. The thing these spark plugs had in common were that they were all Champion-brand plugs and they all measured very high resistance or even open-circuit when tested with an ohmmeter.

We also saw a number of cases where high-resistance Champion plugs caused serious internal arc-over damage to Slick magnetos (mostly in Cirrus SR20s). If the damaged mag was replaced without replacing the spark plug, the new mag would be damaged in short order. The cause-and-effect relationship was pretty obvious.

In researching this issue, I looked at the magneto troubleshooting guide on the Aircraft Magneto Service website, maintained by mag guru Cliff Orcutt who knows more about aircraft ignition systems than just about anyone I know. Cliff owns and operates my favorite mag specialty shop, and that’s where I send the mags on my own airplane every 500 hours for inspection and tune-up. In reading Cliff’s troubleshooting guide, I came across the following pearls of wisdom:

  • Take an OHM Meter and measure the resistance value from the connection in the bottom of the barrel to the clean center electrode at the firing end, electrode must be bare metal.
  • A new Champion plug will have a value of 800 to 1200 OHMS. New Tempest (formerly Unison-Autolite) will measure 1000 OHMS.  Replace any plug above 5000 OHMS.
  • A spark plug bomb tester can test a bad plug and lead you to conclude it is serviceable. The OHM Meter check is simple, readily available, and amazingly accurate in finding misfiring plugs.

We started asking the maintenance shops we hired to maintain our clients’ aircraft to ohm out the plugs at each 50-hour spark plug maintenance cycle. The number of plugs that measured over 5,000 ohms was eye-opening. Many plugs measured tens or hundreds of thousand ohms, and it wasn’t unusual to find plugs that measured in the megohm range or even totally open-circuit. Here, for example, is a set of 12 Champion plugs removed for cleaning and gapping from a Cirrus SR22 by a shop in South Florida:

Champion spark plug resistance

Notice that only two of these 12 plugs measured less than 5K ohms, and one of those had to be rejected because its nose core insulator was cracked (a separate issue affecting only Champion fine-wire spark plugs, and unrelated to the resistor issue that affected all Champion plugs).

Why spark plugs have resistors

Worn spark plug

A worn-out spark plug.

Early aviation spark plugs didn’t contain resistors. They didn’t last long, either. The reason was that each time the plug fired, a significant quantity of metal was eroded from the electrodes. Magnetos fire alternate spark lugs with alternate polarities, so half of the plugs suffered accelerated erosion of their center electrodes, and the other half suffered erosion of the ground electrodes. Eventually, the ground electrodes became so thin or the center electrode became so elliptical that the plug had to be retired from service.

Spark plug manufacturers found that they could extend the useful life of their plugs by adding an internal resistor to limit the current of the spark that jumps across the electrodes. The higher the resistance, the lower the current. And the lower the current, the less metal eroded from the electrodes and the longer the plug would last before the electrodes got so worn that the plug had to be retired.

Adding a resistor to the plug also raised the minimum firing voltage for a given electrode gap. The result is a hotter, more well-defined spark that improves ignition consistency and reduces cycle-to-cycle variation.

The value of the resistor was fairly critical. If the resistance was too high, the plug would fire weakly, resulting in engine roughness, hard starting, excessive mag drops, and (if the resistance was high enough) arc-over damage to the magneto and/or harness. If the resistance was too low, the plug electrodes would erode at an excessive rate and its useful life would be short. Experimentation showed that a resistance between 1K and 4K ohms turned out to be a good compromise between ignition performance and electrode longevity. Brand new Champion-brand aviation spark plugs typically measure around 1,200 ohms fresh out of the box. New Tempest-brand plugs typically measure about 2,500 ohms. Both of these represent good resistance values right in the sweet spot.


As word of these erratic and wildly out-of-spec resistance values began reaching aircraft owners and mechanics (primarily via the Internet), Champion went on the defensive. At numerous aviation events and IA renewal seminars, Champion reps dismissed the significance of resistance measurements. They explained that the silicon carbide resistor in Champion-brand plugs is made to show the proper resistance whenever a high-voltage pulse is present, and can’t necessarily be measured properly with an ohmmeter. Further, they stated that the proper way to test a spark plug is on a spark plug testing machine (so-called “bomb tester”), and claimed that if a plug functions well during a bomb test, it should function well in the airplane.

Champion old insulator assembly

Champion old insulator assembly.

Of course, this “company line” from Champion didn’t agree with our experience. We’d seen numerous instances of high-resistance Champion plugs that tested fine on the bomb tester but functioned erratically in service. Nor did it agree with the Mil Spec for aviation spark plugs (MIL-S-7886B) which states clearly:

4.7.2 Resistor. Each spark plug shall be checked for stability of internal resistance and contact by measurement of the center wire resistance by the use of a low voltage ohmmeter (8 volts or less). Center wire resistance values of any resistor type spark plug shall be as specified in the manufacturer’s drawings or specifications. 

One enterprising Cessna 421 owner named Max Nerheim performed high-voltage testing of Champion spark plugs, and found that plugs that measure high-resistance or open-circuit with a conventional ohmmeter also had excessive voltage drop when fired with high voltage, and required a higher minimum voltage to produce any spark. Max Nerheim wasn’t just an aircraft owner, mind you, he was also Vice President of Research for TASER International, Inc. and was exceptionally qualified to perform high-voltage testing of Champion spark plugs. Nerheim’s findings flatly contradicted Champion’s company line, and agreed with what we were seeing in the field. Nerheim also disassembled the resistor assemblies of a number of high-resistance Champion plugs and found that the internal resistor “slugs” were failing.


What's your resistance?The spit really hit the fan when Champion’s primary competitor in the aviation spark plug space, Aero Accessories, Inc., launched a marketing campaign to promote sales of its Tempest-brand aviation spark plugs by highlighting the resistance issue. (Aero Accessories acquired the Autolite line of aviation spark plugs from Unison Industries in 2010, an re-branded them under its Tempest brand.) In February 2013, they issued a Tempest Tech Tip titled “The Right Way to Check Spark Plug Resistors,” started selling a fancy spark plug resistance tester, and launched a big “What’s Your Resistance” advertising campaign in the general aviation print media.

Predictably, this provoked a rather hostile response from Champion. Their field reps ratcheted up their public relations campaign claiming that the ohmeter check was meaningless, and insisting that Champion spark plugs didn’t have a resistance problem that affected the performance of their plugs.


In the face of both overwhelming technical evidence from the field that their spark plugs had a resistor problem, and a virtual blitzkrieg from their principal competitor that was starting to erode their dominant market share, Champion began having some self-doubts. Max Nerheim discussed his high-voltage test findings with Kevin Gallagher, Manger of Piston and Airframe at Champion Aerospace, and Gallagher acknowledged that Champion was looking into the issue with the resistor increasing in impedance, but did not have it resolved yet. Meanwhile, the Champion field reps continued to insist to anyone who would listen that claims of resistor problems in Champion spark plugs were false and that the ohmmeter test was meaningless.


Sometime in late 2014, it appears that Champion very quietly changed the internal design of their spark plugs to use a sealed, fired-in resistor element that appears to be quite similar to the design of the Tempest/Autolite plug. They didn’t change any part numbers. So far as I have been able to tell, they didn’t even issue a press release. The Champion Aerospace website makes no mention of any recent design changes or product improvements. But the cutaway diagram of the Champion spark plug now on the website shows the new fired-in resistor. Here are the old and new cutaway diagrams. Compare them and you’l clearly see the difference.

Click on images below to see higher-resolution versions.

Champion spark plug cutaway (old)

Champion spark plug cutaway (old)

Champion spark plug cutaway (new)

Champion spark plug cutaway (new)

I checked with a number of A&P mechanics and they verified that the latest Champion spark plugs they ordered do indeed have the new design. It’s easy to tell whether a given Champion spark plug is of the old or new variety. Simply look at the metal contact located at the bottom of the “cigarette well” on the harness end of the plug. The older-design plugs have a straight screwdriver slot machined into the metal contact, while the newer-design plugs do not.

As I write this, it’s still too early to tell whether Champion’s quiet resistor redesign will cure the drifting resistance problem, but my best guess is that it will. If I’m right, this is very good news indeed for users of Champion aviation spark plugs. I applaud Champion Aerospace for improving its product.

Still, I can’t help but wonder why it took six years for the company to work through its grief from denial to acceptance. I suppose grief is a very personal thing, and everyone deals with it differently.

Ron Rapp

How Far is Far Enough?

March 9th, 2015 by Ron Rapp

There’s an old saying about fuel: unless you’re on fire, you can never have enough. I wonder, is the same thing true of an aircraft’s range?

With a 7,000 nautical mile reach, Gulfstream’s G650 was already an ultra-long range business jet before the ‘ER’ edition tacked on an additional 500 nm of capability. The G-series flagship recently set two records while flying around the world with a single fuel stop.

To be fair, Steve Wynn’s G650 flew eastbound from New York to Beijing and continued east to Savannah, Georgia for a total distance of 13,511 nautical miles. While that may satisfy the practical definition of the phrase, it doesn’t come close to the actual 21,600 nm equatorial circumference of the planet. Lest you think I’m picking nits, consider that you could fly “around the world” near the north pole with a Cessna 172 and do it on a single tank of gas. Get close enough to the pole and you could walk around the world in a few seconds. Doing so wouldn’t necessarily make you Superman.

Clearly, some kind of definition would be helpful. For the purposes of aeronautical records, a circumnavigation is considered by the Fédération Aéronautique Internationale to be a flight which a) covers a distance no less than the length of the Tropic of Cancer, b) crosses all meridians, and c) begins and ends at the same airport. In other words, the FAI’s criteria requires a minimum flight of 19,853 nautical miles, or 6,342 further than Wynn’s G650 traveled.

This is not to denigrate the G650’s achievement. They flew a long way, and did it at a high rate of speed — Mach 0.87. The city pair records it set on this trip will probably stand for a long time. But I can’t help but wonder, how much further could a person want to go? How much range is “far enough”? Since the globe is 21,600 nautical miles in circumference, one might be tempted to assume the answer is 10,800 nm. If airplanes were used to travel between random geographic points, that might make sense, but they’re using to travel between airports. Usually the ones near major cities.

One of the longest city pairs is Rio de Janeiro to Tokyo, about 10,000 nautical miles. Auckland to London is about the same. If that was the typical mission, the G650ER’s 7,500 nm range could still be improved upon by a longer-range airplane. But for the vast majority of pairings on our little blue marble, the ER can already do it on a single tank.

It seems to me that eking out those final miles may come at a steep price. Beyond the monetary cost, it would involve heavier weights, longer wings, the requirement for additional crewmembers, and so on. Even if the only thing needed was greater efficiency via winglets, incremental engine improvements, aerodynamic cleanup, and so on, it would still require vital resources like time and money — limitations every bit as real as the ones we face with smaller aircraft.

So should we expect to see longer range airplanes being developed, or will future emphasis be placed on speed and comfort? As always, the market will dictate the answer. Nobody develops a $60 million conveyance without extensive consultation with their client base. It’s worth noting that the G650 is such an exceptional product because it made significant strides in speed, range, and comfort simultaneously. That’s rare. By contrast, the upcoming G500 and G600 don’t break new ground in terms of speed or range, but do provide improved technology and most of the 650’s hallmark capabilities at a lower price point.

I’ve gone on record as predicting that the next big jump will be an increase in cruise speed — namely, a supersonic business jet. At the end of the day, that’s the ultimate goal: compressing time. Eliminating fuel stops is certainly one way to do it, but that only takes you so far. What comes next when the need to refuel is gone? Once the sound barrier is broken, the race will really be on. You’ll see officially recognized circumnavigations occurring on a much faster and more frequent basis, and business aviation’s value will rise exponentially.

Jolie Lucas

Think outside the traffic pattern: If you build it, they will come!

March 8th, 2015 by Jolie Lucas

Find ways to make your home ‘drome unique and reap the dual benefits of increased activity & fun.

Santa Rosa-Route 66 Airport [KSXU], NM  A Ride from Police  Flying home from AirVenture last year on flight following with Albuquerque Center when the controller asked me if my destination was Santa Rosa-Route 66 airport [KSXU]. I said, “Affirmative KSXU.”  He then said, “If you are in need of a courtesy car make sure to check the bulletin board in the FBO for instructions.”I thanked him for the information, although I thought it was a little odd for ATC to offer suggestions on ground transportation. Landing about 3:30 p.m. after a long flight, I was a little dismayed not to see a car outside the FBO.

Getting a ride and a little history of Santa Rosa-Route 66

Getting a ride and a little history of Santa Rosa-Route 66

Santa Rosa airport is about 4 miles out of town and the idea of walking in to town wasn’t so appealing.  There were a few other planes on the ramp and a small concrete block FBO building. When I went inside and took a look at the bulletin board I was surprised to see a sign that said to call the Santa Rosa Police Department for a ride in to town. Even though I was a little nervous about it, I called the number on the sign and told the dispatcher that I was at the airport and needed a ride.  “We will send a cruiser out for you in a moment.”  she said.

Sure enough, in about five minutes up rolled a police cruiser and driven by a very nice young officer.  He helped load up the bags and I got in the back of the car.  A little caveat that I have never been in the back of a police car.  The funniest part was when I tried to open the car door to get out when he stopped at the hotel.

Here are some more examples of bringing some fun to the airport, which in turn brings visitors and economic gain.

Pecos, Texas [KPEQ] Homemade Burritos for All  The FBO managers of Pecos Texas offer their visitors homemade burritos, chips and salsa.  This airport gets a fair share of military and business customers.  Texas hospitality and the yummy food entices folks to stop, stay and buy fuel.

Beaumont, KS [07S]  Taxi Plane to Town  This $100 Hamburger stop  in southern Kansas allows you to land and taxi in to town. The runway of prairie grasses about a quarter mile east of “town” such as it is north-south orientation, about 2,600 feet long, sloping downhill from north to south.

Twin Beech taxi to town, Beaumont KS.

Twin Beech taxi to town, Beaumont KS.

You land, taxi off the south end of the runway and turn west onto 118th street , taxi west, uphill, to a three-way stop at the intersection adjacent to the jerkwater tower, across the intersection and south to the aircraft-only parking…walk north across the street and you’re there….they have a monthly fly-in breakfast, a monthly ride-in breakfast (for the motorcycle crowd), and other events through warmer months.

Priest Lake Idaho [67S]  Donuts and Coffee for Campers  Located near breathtaking Cavanaugh Bay is Priest Lake airport which has a grass strip and camping. There is a courtesy golf cart to help unload the plane and transport gear to camp site.  Each morning the caretaker brings fresh coffee and donuts out to campers .

Burning Man

Burning Man


Black Rock City

Black Rock City Airport [88NV] Burning Man  In 2009 Black Rock City Airport was recognized by the FAA as a private airport and designated 88NV. With all volunteer labor, once a year a portion of playa of the desert is transformed into an airport. Fly-In guests get to land on an airport that only exists one week per year.

Alton Bay on Lake Winnipesaukee, New Hampshire [B18]  Only FAA Ice Runway in lower 48 Since the 1960s airplanes have flocked to the “ice airport”. If you are actually the PIC and land at the airport, you are eligible to purchase a commemorative hat.  According to one pilot who landed there, they are strict about the one hat per pilot rule and keep a log. 

Land on ice, get a hat

Land on ice, get a hat

We can all do a little something to make our airports attractive to guests.  The fun-factor the airports I have listed above helps increase good-will and numbers of visitors. Check out the comment section on AirNav and you will see that pilots like to leave feedback and tips for other pilots.   What can you do at your home airport?  Or better yet, what has your airport done already?  Please use the comments section below to add the unique service, attraction or treat that your airport offers.   I think that pilots are inherently kids at heart.  Let’s get the movement rolling here.  Be unique, think outside the traffic pattern. If you build it, they will come.






Amy Laboda

Where Dreams Take Us

March 2nd, 2015 by Amy Laboda

I have a secret: When I was a little girl, way, way back in the ancient 1960s, I wanted to be an astronaut. I followed everything and anything that had to do with Space, and that included watching Star Trek (yes, the original Star Trek, starring William Shatner, George Takei, and Leonard Nimoy). You may remember these guys for their later work, but I knew them when they were idols. But they weren’t my role models.

No, that went to a woman who wasn’t even sure she wanted to keep the part of communications officer on the show. Nichelle Nichols played Nyota Uhura and she was something else. A beautiful black woman in a role of responsibility on a space ship with a mission to discover. It simply doesn’t get any better than that. She told an interviewer that she had, at one point, wanted to move on to other roles, but in a chance encounter with Dr. Martin Luther King she learned something that had never occurred to her; he told her she had become a role model to little girls everywhere, and that she simply could not quit. King was compelling. Nichols stuck with the role.

If I’d been more of a history buff than a child wont to sit around and watch TV I might have admired Jerrie Cobb, Janey Hart or Wally Funk. All three were women who were part of a nascent and highly experimental program to see if women could become astronauts. They and several other women with aviation experience were invited by William Lovelace II to participate in Phase I astronaut physiological and psychological testing at his clinic, using the same equipment that had been used on the Mercury astronauts (all men).

Thirteen of the women (sometimes known as the Mercury 13, although they prefer the acronym FLATs, for Fellow Lady Astronaut Trainees) passed all the tests in Phase I. Three women went through Phase II testing, and after passing, waited patiently for an invitation to Pensacola, Florida, for Phase III. At this point the women were beginning to get excited; perhaps NASA really did want women to fly in Space. Except the invitation never came.

Janey Hart and Jerrie Cobb testified to their fitness for Space flight before the U.S. Congress in July 1962, but to no avail. The United States was simply not ready for women to put their lives at risk by climbing in a capsule on the tip of a massive rocket and blasting into space.

Instead the country let its then arch rival, the USSR (now Russia) pick up the gauntlet. Valentina Vladimirovna Tereshkova, an expert parachutist, was launched into space with much fanfare barely one year later, in June 1963. She went on to positions of note in the communist party, and was last seen carrying the Olympic flag at the 2014 Sochi Winter Olympics opening ceremony.

I wish I’d known about these women as a child, when my father used to take me in our Mooney up to Titusville to watch the Apollo launches. He let me fly right seat, and even take the controls. When I was old enough, he bought me flying lessons. Because of that I managed to follow my dreams into aviation.

I never became an astronaut. Then again, I never stopped yearning for space.

Instead I became a cheerleader for others, from Sally Ride to Eileen Collins to Mae Jamison, Barbara Morgan and beyond. I turned up for numerous Space Shuttle launches, as excited as ever to watch each one thunder to the heavens. The astronaut corps today is a multiracial, multinational group; a lot like us. And opportunity? It’s still there. Hollywood is still inspiring kids, and good souls such as my father are still offering curious children a chance to fly.

Want to know more about upcoming events that are designed to inspire? Fly It Forward is happening March 2 through 8 in locations all over the world. Click here for more information.


Rob Mark

Look Ma … No Hands

February 23rd, 2015 by Rob Mark

Photo courtesy FS-Force

As a kid, telling your mom you planned to try something without holding on was a tipoff that something dangerous was surely in the offing.

But when I tell flying students to try letting go of the control wheel or stick at times when I first get to know them, I’m actually trying to help them become better pilots. In my case, it’s all about learning to trim the airplane. Pilots who fail to learn the purpose of the trim tab – that little piece of hinged metal on the end of the elevator – or the movable horizontal stabilizer really are doomed to work way too hard at becoming truly good pilots. I often find though that many instructors don’t take enough time to explain the “why” behind trimming an airplane.

Most simply put, trim tabs help maintain an airplane’s state of balance where all four of those basic forces we learned about as student pilots — power, lift, drag and gravity — come together. Alter any of the forces and you’ll need to re-trim the aircraft to reestablish that balance.

Failure to reestablish balance and the pilot’s forced to hold back or forward pressure on the control wheel to maintain altitude or airspeed. That might not seem like a big deal, but it’s just one more brain function that’s not available for other important things like navigating, looking out the window for other airplanes or drones, or keeping an eye on the weather. Read the rest of this entry »

Mike Busch

Owner in command

February 17th, 2015 by Mike Busch

Every pilot understands the notion of “pilot in command.” That’s because we all had some certificated flight instructor (CFI) who mercilessly pounded this essential concept into our heads throughout our pilot training. Hopefully, it stuck.

As pilot-in-command (PIC), we are directly responsible for, and the final authority as to, the operation of our aircraft and the safety of our flight. Our command authority so absolute that in the event of an in-flight emergency, the FAA authorizes the PIC to deviate from any rule or regulation to the extent necessary to deal with that emergency. (14 CFR §91.3)

In four and a half decades of flying, I’ve overheard quite a few pilots dealing with in-flight emergencies, and have dealt with a few myself. It makes me proud to hear a fellow pilot who takes command of the situation and deals with the emergency decisively. Such decisiveness is “the right stuff” of which PICs are made, and what sets us apart from non-pilots.

Conversely, it invariably saddens me to hear a frightened pilot abdicate his PIC authority by throwing himself on the mercy of some faceless air traffic controller or flight service specialist to bail him out of trouble. How pathetic! The ATC or FSS folks often perform heroically in such “saves,” but few of them are pilots, and most have little or no knowledge of the capabilities of the emergency aircraft or its crewmember(s). They shouldn’t be placed in the awful position of having to make life-or-death decisions on how best to cope with an in-flight emergency. That’s the PIC’s job.

Fortunately, most of us who fly as PIC understand this because we had good CFIs who taught us well. When the spit hits the fan, we take command almost instinctively.

Owner in command

When a pilot progresses to the point of becoming an aircraft owner, he suddenly takes on a great deal of additional responsibility and authority for which his pilot training most likely did not prepare him. Specifically, he becomes primarily responsible for maintaining his aircraft in airworthy condition, including compliance with all applicable airworthiness requirements including Airworthiness Directives. (14 CFR §91.403) Unfortunately, few owners have the benefit of a Certificated Ownership Instructor (COI) to teach them about their daunting new responsibilities and authority as “owner in command” (OIC).

Consequently, too many aircraft owners fail to comprehend or appreciate fully their weighty and complex OIC responsibilities. They put their aircraft in the shop, hand over their keys and credit card, and tell the mechanic to call them when the work is done and the airplane is ready to fly. Often, owners give the mechanic carte blanche to “do whatever it takes to make the aircraft safe,” and don’t even know what work is being performed or what parts are being replaced until after-the-fact when they receive a maintenance invoice.

In short, lots of owners seem to act as if the mechanic is responsible for maintaining the aircraft in airworthy condition. But that’s bass-ackwards. In the eyes of the FAA and under the FARs, it’s the owner who is responsible. The mechanic is essentially “hired help”—a skilled and licensed contractor hired to assist the owner carry out his regulatory responsibilities.

General Contractor

An aircraft owner-in-command acts as the “general contractor” for the maintenance of his aircraft.

I find it helpful to compare the proper role of the aircraft owner in maintaining an airworthy aircraft to that of a general contractor in building a house. The general contractor needs to hire licensed specialists—electricians, plumbers, roofers, masons, and other skilled tradesmen—to perform various tasks required during the construction. He also needs to hire a licensed building inspector to inspect and approve the work that the tradesman have performed. But, the general contractor makes the major decisions, calls the shots, keeps things within schedule and budget constraints, and is held primarily accountable for the final outcome.

Similarly, an aircraft owner hires certificated airframe and powerplant (A&P) mechanics to perform maintenance, repairs and alterations; certificated inspectors (IAs) to perform annual inspections, and other certificated specialists (e.g., avionics, instrument, propeller and engine repair stations) to perform various specialized maintenance tasks. But, the owner is the boss, is responsible for hiring, firing, and managing these various “subcontractors,” and has primary responsibility for the ensuring the desired outcome: a safe, reliable aircraft that meets all applicable airworthiness requirements, achieved within an acceptable maintenance budget and schedule.

Who’s the boss?

The essence of the owner-in-command concept is that the aircraft owner needs to remain in control of the maintenance of his aircraft, just as the pilot needs to remain in control of the operation of the aircraft in-flight. When it comes to maintenance, the owner is supposed to be the head honcho, make the major decisions, ride herd on time and budget constraints, and generally call the shots. The mechanics and inspectors and repair stations he hires are “subcontractors” with special skills, training and certificates required to do the actual work. But the owner must always stay firmly in charge, because the buck stops with him (literally).

Since most owners have not received training in how to act as OIC, many of them are overwhelmed by the thought of taking command of the maintenance of their aircraft. “I don’t know anything about aircraft maintenance,” they sigh. “That’s way outside my comfort zone. Besides, isn’t that my mechanic’s job?”

Such owners often adopt the attitude that it’s their job to fly the aircraft and the mechanic’s job to maintain it. They leave the maintenance decisions up to the mechanics, and then get frustrated and angry when squawks don’t get fixed and maintenance expenses are higher than they expected.

But think about it: If you were building a house and you told your plumber or electrician or roofer “just do whatever it takes and send me the bill when it’s done,” do you think you’d be happy with the result?

No one in his right mind would do that, of course. If you were hiring an electrician to wire your house, you’d probably start by giving him a detailed list of exactly what you want him to do—what appliances and lighting fixtures you want installed in each room, where you want to locate switches, dimmers, convenience outlets, thermostats, telephone jacks, Ethernet connections, and so forth. You’d then expect the electrician to come back to you with a detailed written proposal, cost estimate, and completion schedule. After going over the proposal in detail with the electrician and making any necessary revisions, you’d sign the document and thereby enter into a binding agreement with the electrician for specific goods and services to be provided at a specific price and delivery date.

You’d do the same with the carpenter, roofer, drywall guy, paving contractor, and so forth.

Cars vs. airplanes

If you’ll permit me to mix my metaphors, when I take my car to the shop for service, the shop manager starts by interviewing me and taking notes on exactly what I want done—he asks me to describe any squawks I have to report, and he checks the odometer and explains any recommended preventive maintenance. Once we arrive at a meeting of the minds about what work needs to be done, the shop manager writes up a detailed work order with a specific cost estimate, and asks me to sign it and keep a copy. In essence, I now have a written contract with the shop for specific work to be done at a specific price.

The service manager doesn’t do this solely out of the goodness of his heart. He’s compelled to do so. In California where I live, state law provides that the auto repair shop is required to provide me with a written estimate in advance of doing any work, and may not exceed the agreed-to cost estimate by more than 10% unless I explicitly agree to the increase. If the shop doesn’t follow these rules, I can file a complaint with the State Bureau of Automotive Repairs and they’ll investigate and take appropriate action against the shop. Most states have similar laws.

Discrepancy List & Repair Estimate

Aircraft owners should insist on receiving a detailed written work statement and cost estimate like this one before authorizing any mechanic or shop to perform repairs or install replacement parts.

Unfortunately, there are no such laws requiring aircraft maintenance shops to deal with their customers on such a formalized and businesslike basis, even though the amounts involved are usually many times larger. Aircraft owners routinely turn their airplanes over to a mechanic or shop with no detailed understanding of what work will be done, what replacement parts will be installed, and what it’s all going to cost. All too often, the aircraft owner only finds this out when he picks up the aircraft and is presented with an invoice (at which point it’s way too late for him to influence the outcome).

It always amazes me to see aircraft owners do this. These are intelligent people, usually successful in business (which is what allows them to afford an airplane), who would never consider making any other sort of purchase of goods or services without first knowing exactly what they were buying and what it costs. Yet they routinely authorize aircraft maintenance without knowing either.

Often, the result is sticker shock and hard feelings between the owner and the shop. There’s no State Bureau of Aircraft Repair to protect aircraft owners from excessive charges or shoddy work. The FAA almost never gets involved in such commercial disputes. A few owners even wind up suing the maintenance shop, but generally the only beneficiaries of such litigation are the lawyers.

You can’t un-break an egg. You’ve got to prevent it from breaking in the first place.

Trust but verify

I hear from lots of these disgruntled aircraft owners who are angry at some mechanic or shop. When I ask why they didn’t insist on receiving a detailed work statement and cost estimate before authorizing the shop to work on their aircraft, I often receive a deer-in-the-headlights look, followed by some mumbling to the effect that “I’ve never had a problem with them before” or “you’ve got to be able to trust your A&P, don’t you?”

Sure you do…and you’ve got to be able to trust your electrician, plumber and auto mechanic, too. But that’s no excuse for not dealing with them on a businesslike basis. Purchasing aircraft maintenance services is a big-ticket business transaction, and should be dealt with as you would deal with any other big-ticket business transaction. The buyer and seller must have a clear mutual understanding of exactly what is being purchased and what it will cost, and that understanding must be reduced to writing.

In the final analysis, the most important factor that sets a maintenance-savvy aircraft owner apart from the rest of the pack is his attitude about maintenance. Savvy owners understand that they have primary responsibility for the maintenance of their aircraft, and that A&Ps, IAs and repair stations are contractors that they must manage. They deal with these maintenance professionals as they would deal with other contractors in other business dealings. They insist on having a written work statement and cost estimate before authorizing work to proceed. Then, like any good manager, they keep in close communication with the folks they’ve hired to make sure things are going as planned.

If your mechanic or shop resists working with you on such a businesslike basis, you probably need to take your business elsewhere.