Quest for a TBO-Free Engine

“It just makes no sense,” Jimmy told me, the frustration evident in his voice. “It’s unfair. How can they do this?”

Jimmy Tubbs, ECi’s legendary VP of Engineering

Jimmy Tubbs, ECi’s legendary VP of Engineering

I was on the phone with my friend Jimmy Tubbs, the legendary Vice President of Engineering for Engine Components Inc. (ECi) in San Antonio, Texas. ECi began its life in the 1940s as a cylinder electroplating firm and grew to dominate that business. Starting in the mid-1970s and accelerating in the late 1990s—largely under Jimmy’s technical stewardship—the company transformed itself into one of the two major manufacturers of new FAA/PMA engine parts for Continental, Lycoming and Pratt & Whitney engines (along with its rival Superior Air Parts).

By the mid-2000s, ECi had FAA approval to manufacture thousands of different PMA-approved engine parts, including virtually every component of four-cylinder Lycoming 320- and 360-series engines (other than the Lycoming data plate). So the company decided to take the next logical step: building complete engines. ECi’s engine program began modestly with the company offering engines in kit form for the Experimental/Amateur-Built (E-AB) market. They opened an engine-build facility where homebuilders could assemble their own ECi “Lycoming-style” engines under expert guidance and supervision. Then in 2013, with more than 1,600 kit-built engines flying, ECi began delivering fully-built engines to the E-AB market under the “Titan Engines” brand name.

Catch 22, FAA-style

ECi’s Titan Exp experimental engine

A Titan engine for experimental airplanes.
What will it take to get the FAA to certify it?

Jimmy is now working on taking ECi’s Titan engine program to the next level by seeking FAA approval for these engines to be used in certificated aircraft. In theory, this ought to be relatively easy (as FAA certification efforts go) because the Titan engines are nearly identical in design to Lycoming 320 and 360 engines, and almost all the ECi-built parts are already PMA approved for use in Lycoming engines. In practice, nothing involving the FAA is as easy as it looks.

“They told me the FAA couldn’t approve an initial TBO for these engines longer than 1,000 hours,” Jimmy said to me with a sigh. He had just returned from a meeting with representatives from the FAA Aircraft Certification Office and the Engine & Propeller Directorate. “I explained that our engines are virtually identical in all critical design respects to Lycoming engines that have a 2,000-hour TBO, and that every critical part in our engines is PMA approved for use in those 2,000-hour engines.”

“But they said they could only approve a 1,000-hour TBO to begin with,” Jimmy continued, “and would consider incrementally increasing the TBO after the engines had proven themselves in the field. Problem is that nobody is going to buy one of our certified engines if it has only a 1,000-hour TBO, so the engines will never get to prove themselves. It makes no sense, Mike. It’s not reasonable. Not logical. Doesn’t seem fair.”

I certainly understood where Jimmy was coming from. But I also understood where the FAA was coming from.

A brief history of TBO

To quote a 1999 memorandum from the FAA Engine & Propeller Directorate:

The initial models of today’s horizontally opposed piston engines were certified in the late 1940s and 1950s. These engines initially entered service with recommended TBOs of 500 to 750 hours. Over the next 50 years, the designs of these engines have remained largely unchanged but the manufacturers have gradually increased their recommended TBOs for existing engine designs to intervals as long as 2,000 hours. FAA acceptance of these TBO increases was based on successful service, engineering design, and test experience. New engine designs, however, are still introduced with relatively short TBOs, in the range of 600 hours to 1,000 hours.

From the FAA’s perspective, ECi’s Titan engines are new engines, despite the fact that they are virtually clones of engines that have been flying for six decades, have a Lycoming-recommended TBO of 2,000 hours, and routinely make it to 4,000 or 5,000 hours between overhauls.

Is it any wonder we’re still flying behind engine technology designed in the ‘40s and ‘50s? If the FAA won’t grant a competitive TBO to a Lycoming clone, imagine the difficulties that would be faced by a company endeavoring to certify a new-technology engine. Catch 22.

Preparing for an engine test cell endurance run.

Incidentally, there’s a common misconception that engine TBOs are based on the results of endurance testing by the manufacturer. They aren’t. The regulations that govern certification of engines (FAR Part 33) require only that a new engine design be endurance tested for 150 hours in order to earn certification. Granted, the 150-hour endurance test is fairly brutal: About two-thirds of the 150 hours involves operating the engine at full takeoff power with CHT and oil temperature at red-line. (See FAR 33.49 for the gory details.) But once the engine survives its 150-hour endurance test, the FAA considers it good to go.

In essence, the only endurance testing for engine TBO occurs in the field. Whether we realize it or not, those of us who fly behind piston aircraft engines have been pressed into service as involuntary beta testers.

What about a TBO-free engine?

“Jimmy, this might be a bit radical” I said, “but where exactly in FAR Part 33 does it state that a certificated engine has to have a recommended TBO?” (I didn’t know the answer, but I was sure Jimmy had Part 33 committed to memory.)

“Actually, it doesn’t,” Jimmy answered. “The only place TBO is addressed at all is in FAR 33.19, where it says that ‘engine design and construction must minimize the development of an unsafe condition of the engine between overhaul periods.’ But nowhere in Part 33 does it say that any specific overhaul interval must be prescribed.”

“So you’re saying that engine TBO is a matter of tradition rather than a requirement of regulation?”

“I suppose so,” Jimmy admitted.

“Well then how about trying to certify your Titan engines without any TBO?” I suggested. “If you could pull that off, you’d change our world, and help drag piston aircraft engine maintenance kicking and screaming into the 21st century.”

An FAA-inspired roadmap

I pointed out to Jimmy that there was already a precedent for this in FAR Part 23, the portion of the FARs that governs the certification of normal, utility, aerobatic and commuter category airplanes. In essence, Part 23 is to non-transport airplanes what Part 33 is to engines. On the subject of airframe longevity, Part 23 prescribes an approach that struck me as being also appropriate for dealing with engine longevity.

Since 1993, Part 23 has required that an applicant for an airplane Type Certificate must provide the FAA with a longevity evaluation of metallic  wing, empennage and pressurized cabin structures. The applicant has the choice of three alternative methods for performing this evaluation. It’s up to the applicant to choose which of these methods to use:

  • “Safe-Life” —The applicant must define a “safe-life” (usually measured in either hours or cycles) after which the structure must be taken out of service. The safe-life is normally established by torture-testing the structure until it starts to fail, then dividing the time-to-failure by a safety factor (“scatter factor”) that is typically in the range of 3 to 5 to calculate the approved safe-life of the structure. For example, the Beech Baron 58TC wing structure has a life limit (safe-life) of 10,000 hours, after which the aircraft is grounded. This means that Beech probably had to torture-test the wing spar for at least 30,000 hours and demonstrate that it didn’t develop cracks.
  • “Fail-Safe” —The applicant must demonstrate that the structure has sufficient redundancy that it can still meet its ultimate strength requirements even after the complete failure of any one principal structural element. For example, a three-spar wing that can meet all certification requirements with any one of the three spars hacksawed in half would be considered fail-safe and would require no life limitation.
  • “Damage Tolerance” —The applicant must define a repetitive inspection program that can be shown with very high confidence to detect structural damage before catastrophic failure can occur. This inspection program must be incorporated into the Airworthiness Limitations section of the airplane’s Maintenance Manual or Instructions for Continued Airworthiness, and thereby becomes part of the aircraft’s certification basis.

If we were to translate these Part 23 (airplane) concepts to the universe of FAR Part 33 (engines):

  • Safe-life would be the direct analog of TBO; i.e., prescribing a fixed interval between overhauls.
  • Fail-safe would probably be impractical, because an engine that included enough redundancy to meet all certification requirements despite the failure of any principal structural element (e.g., a crankcase half, cylinder head or piston) would almost surely be too heavy.
  • Damage tolerance would be the direct analog of overhauling the engine strictly on-condition (based on a prescribed inspection program) with no fixed life limit. (This is precisely what I have been practicing and preaching for decades.)

How would it work?

SavvyAnalysis chart

Engine monitor data would be uploaded regularly to a central repository for analysis.

Jimmy and I have had several follow-on conversations about this, and he’s starting to draft a detailed proposal for an inspection protocol that we hope might be acceptable to the FAA as a basis of certifying the Titan engines on the basis of damage tolerance and eliminate the need for any recommended TBO. This is still very much a work-in-progress, but here are some of the thoughts we have so far:

  • The engine installation would be required to include a digital engine monitor that records EGTs and CHTs for each cylinder plus various other critical engine parameters (e.g., oil pressure and temperature, fuel flow, RPM). The engine monitor data memory would be required to be dumped on a regular basis and uploaded via the Internet to a central repository prescribed by ECi for analysis. The uploaded data would be scanned automatically by software for evidence of abnormalities like high CHTs, low fuel flow, failing exhaust valves, non-firing spark plugs, improper ignition timing, clogged fuel nozzles, detonation and pre-ignition. The data would also be available online for analysis by mechanics and ECi technical specialists.
  • At each oil-change interval, the following would be required: (1) An oil sample would be taken for spectrographic analysis (SOAP) by a designated laboratory, and a copy of the SOAP reports would be transmitted electronically to ECi; and (2) The oil filter would be cut open for inspection, digital photos of the filter media would be taken, when appropriate the filter media would be sent for scanning electron microscope (SEM) evaluation by a designated laboratory, and the media photos and SEM reports would be transmitted electronically to ECi.
  • At each annual or 100-hour inspection, the following would be required: (1) Each cylinder would undergo a borescope inspection of the valves, cylinder bores and piston crowns using a borescope capable of capturing digital images, and the borescope images would be transmitted electronically to ECi; (2) Each cylinder rocker cover would be removed and digital photographs of the visible valve train components would be transmitted electronically to ECi; (3) The spark plugs would be removed for cleaning/gapping/rotation, and digital photographs of the electrode ends of the spark plugs would be taken and transmitted electronically to ECi; and (4) Each cylinder would undergo a hot compression test and the test results be transmitted electronically to ECi.

The details still need to be ironed out, but you get the drift. If such a protocol were implemented for these engines (and blessed by the FAA), ECi would have the ability to keep very close tabs on the mechanical condition and operating parameters of each its engines—something that no piston aircraft engine manufacturer has ever been able to do before—and provide advice to each individual Titan engine owner about when each individual engine is in need of an overhaul, teardown inspection, cylinder replacement, etc.

Jimmy even thinks that if such a protocol could be implemented and approved, ECi might even be in a position to offer a warranty for these engines far beyond what engine manufacturers and overhaul shops have been able to offer in the past. That would be frosting on the cake.

I’ve got my fingers, toes and eyes crossed that the FAA will go along with this idea of an engine certified on the basis of damage tolerance rather than safe-life. It would be a total game-changer, a long overdue nail in the coffin of the whole misguided notion that fixed-interval TBOs for aircraft engines make sense. And if ECi succeeds in getting its Titan engine certified on the basis of condition monitoring rather than fixed TBO, maybe Continental and Lycoming might jump on the overhaul-on-condition bandwagon. Wouldn’t that be something?

Mike Busch is arguably the best-known A&P/IA in general aviation, honored by the FAA in 2008 as National Aviation Maintenance Technician of the Year. Mike is a 8,000-hour pilot and CFI, an aircraft owner for 50 years, a prolific aviation author, co-founder of AVweb, and presently heads a team of world-class GA maintenance experts at Savvy Aviation. Mike writes a monthly Savvy Maintenance column in AOPA PILOT magazine, and his book Manifesto: A Revolutionary Approach to General Aviation Maintenance is available from in paperback and Kindle versions (112 pages). His second book titled Mike Busch on Engines was released on May 15, 2018, and is available from in paperback and Kindle versions. (508 pages).


  1. Very interesting. I like it…
    Data integrity would be am important part of this process. I am not sure what this does for complexity, but automatic wireless transmission of data from the engine monitor (with some level of buffering) would be ideal. An alternative would be for the engine monitor to produce encrypted files along with those readable/accessible by the owner.

    • Jim, you’ve touched upon a dream of mine — engine monitors that automatically use telemetry to submit their data to a common repository via a wireless Internet connection. I suspect it will years before we see that happen in certificated aircraft, and I hope I’m still around when it happens. If Boeing 787 engines can do the “ home” trick, why not our Continentals and Lycomings?

  2. Great idea, Mike.

    AOPA, and probably the EAA too, would (should) get behind this idea. They could lend some legislative weight to the FAA consideration of the proposal.

    Good luck!

  3. Seems like an engine monitor these days could include cylinder pressure sensors on each cylinder, perhaps even crank and camshaft rotation sensors, and analyze engine compression on-the-fly (recording suitable summaries) for upload to the engine manufacturer.

    • Probably not, Rick. I’ve talked to George Braly about this. Pressure transducers capable of surviving exposure to a combustion chamber are very expensive, have relatively short useful life, and would either need to be installed in a special tricked-out spark plug (as George does in his test cell at GAMI) or require drilling another hole in the cylinder head. Both of these would present very serious certification challenges.

      • Pity. But if they’re going to certify a new engine, perhaps another hole can be incorporated into the design. I feel like it should be possible to design an appropriate pressure sensor (one with the longevity requirements). Perhaps an acoustical technique could be made to work without penetrating the cylinder?

      • Mike,

        Every engine in every car that was built since about 1990 has accoustic knock sensors that can accurately listen to combustion sounds. Such sensors do not require a hole into the combustion chamber. They need only be attached to the block or head. Of course on a water cooled engine, the water jacket is perfect as it transmits the sounds of every cylinder uniformly to a single sensor that is placed in the cooling jacket. On most car engines these sensors’ primary function is to detect poor combustion, ping (pre-det) or detonation and adjust timing and fuel delivery accordingly to minimize engine damage and limit production of pollution from poor combustion. These same sensors with the proper computer tech can perform even more sophisticated combustion analysis that can be correlated to pressure data taken from test engines and can accurately record the combustion process in each cylinder.

        • That’s a different subject. I’m pretty sure there are already electronic ignitions on E-AB aircraft engines that employ acoustic knock sensors. I’m not sure whether or not Continental’s Aerosance FADEC includes accoustic knock sensors, but I can check.

          I was responding to Rick’s question about combustion chamber pressure sensors, which provide vastly more information than an acoustic knock sensor, but are costly and difficult to implement in a production engine (although they are used in research test cells like the one GAMI operates in Ada, OK).

  4. Fantastic idea, Mike. It brings last century’s engine technology into the 21st century without having to re-invent the whole powerplant. The timing is right, too; digital engine monitors are relatively inexpensive and widely available.

  5. My fingers & toes are also crossed – great idea. AOPA & EAA – get on this bandwagon!!!!!

  6. It would seem that in the interest of liability, ECi may error on the side of caution and instead of risking a lawsuit in an engine failure, would be calling for overhauls or teardown inspections way before necessary.

    What about time based non-use? How would you handle engines that sit idle for years? Do they automatically timeout? What if an owner does not submit data, does teh engine automatically time out so that if the plane is sold, the engine needs to be overhauled?

    Who will pay for all this monitoring and if the engine owner, what is the cost of this over the life of the engine(rough order of magnitude).

    This might be a useful endeavor for high time flight activities like flight schools and charters but for everyday pilots, I dont see the advantage over a 2000 TBO that might last 8 to 10 years and not require an expensive annual data rollup.

    But it is the early stages and I like the new thought process!!

    • I am not suggesting that ECi have the ability to MANDATE overhauls or teardowns, any more than they can now. What I am suggesting is that ECi provide guidance to the owners/operators which they are free to follow or not as they choose, just as now they are free to overhaul at TBO or not as they choose.

      The whole concept of calendar-time-based TBOs is even sillier than the concept of time-in-service-based TBOs. Does anyone really tear down an engine just because it’s 12 years old? Perhaps one could argue that this would make sense for a low-utilization operator in Puerto Rico or Key West, but what about a low-utilization operator in Tucson or Denver or Missoula? You want to know whether your engine has corrosion issues due to disuse? Stick a borescope in the cylinders and look around. (On a Continental, pull a few lifters and have a peek at the cam lobes.) Corrosion needs to be dealt with strictly on-condition just like everything else. Tearing engines down on a fixed timetable is just nuts. And piston GA is the only remaining segment of aviation that still does it this way.

      Condition monitoring will be paid for by the owner/operator, just like any other inspections. The incremental cost would be trivial, because most of the items listed are things that any conscientious aircraft owner should already be doing.

      In my view, each owner/operator should be the sole judge of when to overhaul his engine. If the owner believes in TBO, then let him overhaul at TBO. If he believes in condition monitoring, let him overhaul strictly on-condition. As I often tell clients whose views differ from my own, “do whatever lets you sleep well at night.” That is, after all, the ultimate test. For owner-flown GA, the person who is physically at risk if the engine fails should be the person who decides what maintenance protocol makes him feel comfortable. (For aircraft that carry paying passengers, it’s a different issue, and I’m not going to go there.)

      • Thanks for the thoughtful reply. For it to work, and I think it is a good idea, it has to be thoroughly discussed to unearth pitfalls.

        With engine owners submitting data to ECi for evaluation, then they are looking to ECi for guidance on further necesary steps and not making those decisions on their own, correct?

        I wasnt suggesting that a time-based system be used either… just asking how they would be addressed in a performance based system like you are describing above.

      • Hi Mike, part 91 operators have the option to ignore TBOs, but commercial operators such as flight schools do not have that luxury. Would an overhaul recommendation from ECi based on condition still be optional for commercial operators? I really like the idea and hope you all are successful!

        • Of course it would apply to commercial operators, and it would be most beneficial to commercial operators because they’re the ones that usually are compelled to overhaul at TBO. It would also be of special benefit to other operators (such as flying clubs) who choose to overhaul at TBO due to concerns about civil liability.

  7. The FAA is the sole reason why we are still flying behind antiquated museum pieces of engines (and aircraft) today. Why? Because the FAA’s mandate was to promote commercial aviation and private aviation is the antithesis to commercial aviation so the FAA has thrown every conceivable bureaucratic block at private aviation since it came into existence in 1958!

    I feel for Jimmy and ECi. We at Liquid Cooled Air Power ran into the exact SAME TBO related issue with the FAA! Nowhere in the Part 33 regulations (or any regulations for that matter) is the FAA given the authority to dictate or determine TBO of an engine but they do because they can and we are stuck with engines that were designed and certified in the 1940s because there is no practical way to certify a new engine with an arbitrarily short TBO mandated by the FAA. Our water cooled cylinders can easily achieve a 4000-5000 TBO but proving that in field trials would be impossible since nobody would even consider purchasing our cylinders or converting an aircraft with only a 500-1000 (the range we were given) TBO allowance.

    The FAA has preserved the status quo for the incumbent manufacturers and crushed virtually all practical aircraft and power plant development. The only thing that got past them was Loran and GPS navigation and now they have found ways to totally throttle back those systems by making them exorbitantly expensive to certify and even more expensive to install.

    Remember, private aviation IS the ONLY competition to commercial aviation and commercial interests will do everything possible (remember the demise of the Eclipse 500 Jet?) to prevent private aviation from being developed into a practical transportation alternative to commercial aviation.

    • Bob, I agree that a rewrite of Part 33 would be great. That would take pressure and years to accomplish, but it does need to be done. The FARs are always way, way behind the technology, because the FAA rulemaking folks are always reactive, not proactive. Look at the drone situation.

      But what’s crazy is that engine manufacturers like Continental and Lycoming know amazingly little about how their engines are being operated and how well or poorly they’re holding up. C and L do not know WHEN their engines get overhauled, because there’s no flow of data from the overhaul shops back to C and L. Nor do they know WHY their engines get overhauled: Was it because they reached TBO or because they spun a bearing or because they started using tons of oil? C and L don’t know how long their cylinders are lasting, how often their exhaust valves are burning, how often cylinders are destroyed by destructive detonation or pre-ignition. Of course, the FAA Service Difficulty Report system is a bad joke because nobody submits them.

      Basically C and L only know two things reliably: When warranty claims are submitted and when accidents happen. That’s pathetic.

      If engines were certified through damage tolerance — if there was a mandated condition monitoring program and a requirement that the data be passed back to the manufacturer — then we’d really know how these engines were doing, where they need improvement, how pilots are abusing them, and how much maintenance is actually required to keep them running reliably.

      One way or another, we need to get engine condition-monitoring data flowing into a central database so it can be studied. Damage tolerance certification is one way. Rewriting Part 33 (and/or Part 43 and/or Part 91 Subpart E) is another.

      • Mike,

        I respectfully disagree that C & L have no idea how their engines are being operated. At least the engineers that I have spoken to there demonstrated pretty darn good knowledge of the performance (or non-performance) of their engines. That said they can’t admit to anything less than perfection for liability reasons.

        As for setting up a condition monitoring program – I don’t see that working in the real world – at least not without a fully computer managed engine – something that I would ‘love’ to see happen. But it won’t – not in our lifetime.

        The absurdity is that ECi manufactures certified parts for use on engines with TBOs of 2000 hours yet their own assembly of parts cannot have a TBO of more than 1000 hours to begin with. When yo are dealing with that level of bureaucratic absurdity I see no possibility that a condition monitoring solution will be able to work in the real world.

        I have personally invested close to $1M in the development of Cool Jugs ( and I have come to realize what an utter waste of time and effort it has turned out to be. Not ONE OEM manufacturer showed even the slightest interest! I offered Piper Aircraft a solution on a silver platter and was ignored by the CEO (Chuck Suma) and had the door slammed in my face by the former VP of Engineering and then CEO, John Becker a few years later. In 2001, at Oshkosh, the VP of Engineering at Mooney famously told me (3 days after they declared BK) that ‘there is nothing your engine can do to make our airplane any better’. Of course at the time I didn’t know they were BK – no surprise given the attitude of their VP of Engineering!

        NOBODY (in the US) is willing to invest in GA and the FAA makes it IMPOSSIBLE for anyone to do so. GA in the US is not just dying – its dead – a mere cottage industry of what it once was – all we are witnessing is its death rattle as the remaining of us ‘old’ timers die off. For reference, more Formula One race engines are manufactured each year than ALL of the engines that L and C manufacture for GA! Even if ECi got their engine certified – it would not be certified as a direct replacement for the Lycoming in every airframe. They would need to develop an STC for each and every installation! Good luck on that.

        Sad to say – ECi would be smart to just keep on doing what theya re doing today. Making certified parts and selling complete engines to the experimental market. The certified market is dead!

  8. I like the idea of overhaul on condition, but I have reservations about manufacturers doing the continued airworthiness assessments. This should be a job for a properly trained independent mechanic. Most of the outlined requirements are already done on most aircraft engines at annual/100hr inspections. ECi could outline the parameters that must be met for continued airworthiness but any I/A should be capable of determining burned valves or excessive wear on most components. Multi channel engine analysers are a great idea, but most mechanics should be able to spot a dangerous trend on a graph. I also think that oil analysis is a useful tool for determining when an overhaul may be needed, but third party labs are going to be the better option. If the engine manufacturers outline what is and isn’t airworthy, and maybe offer certification classes for mechanics to be trained to spot the dangerous conditions in house, it would make engine ownership more palatable for the average Joe and their chosen mechanic.

    • We already perform a condition inspection of our engines at least once a year during the annual inspection of the aircraft. We as owners and mechanics already know how to condition inspect an engine and much ado is being made of nothing here. Fundamental flaws in crankshaft and other internal parts are never going to be spotted in any formal condition inspection without requiring a complete engine disassembly. Going through an exercise to formalize this would do nothing more than give the FAA even more power to ground aircraft for arbitrary reasons or demand even more invasive inspections on a whim for those with engines under this approach. In addition the manufacturer would be at even greater economic risk once they have multiple engines in the field since any additional inspection costs mandated by the FAA could be placed (or expected) on the manufacturer to cover.

      The bottom line is that we all take some risk when we fly. And unfortunately despite the best possible efforts on the part of manufacturers some defects can go undetected (recent Lycoming and Continental crankshaft failures and ADs as a result of changing to a new vendor to forge their crankshafts).

      Engines normally don’t just fail – they wear out slowly and dependably and the wear rates are well known and understood with regards to the materials used to build these engines and their operating parameters. The highest wear areas are the upper cylinder walls and exhaust valves, followed by the rings, camshaft, rod bearings, gears and finally the main bearings – in that order. Lower the cylinder head temps and you reduce upper cylinder wear and exhaust valve wear TREMENDOUSLY! Reduce the leakage of partially burned fuel past the rings and REMOVE LEAD FROM THE FUEL and you’ll substantially reduce wear on the cam, rod and main bearings that results from acid buildup in the engine’s oil and simultaneously reduce upper cylinder wear as well.

      A 1960’s car was barely able to get 100K miles before needing a new engine. Sometime after 1985 we started seeing car engine life regularly go to 200-300K miles. What changed? Did Detriot come up with some magic alchemy? Did it start making engines better? No! The lead was removed from the fuel! That alone has been the single biggest contribution to longer engine life in car engines.

      Air cooled engines unfortunately will always have relatively short TBOs compared to water cooled engines because their internal temperatures are WAY higher (about 3 times) than a water cooled engine. Hot metal is ‘softer’ and wears faster and oil’s lubricity is reduced – no mystery! While I appreciate the ‘out-of-the-box’ approach to having a non-TBO engine – we already have that! Aircraft operating in non-commercial service can be operated well past TBO without any special airworthiness requirements. Aircraft in commercial service are already on a condition inspection program and are routinely operated beyond TBO based on condition inspection data. Again – nothing new. Lots of data known. Just talk to any engine overhaul shop and you’ll have a trove of amazing information about the wear characteristics and failure prone parts of any GA engine. The data is there it only needs to be collected and analyzed. The FAA however, only wants to squash the development of GA – and they are more than willing to throw every bureaucratic block that they can.

    • Levi, I agree with you 100% that the engine manufacturer should not be telling the operators when to overhaul and when to change cylinder, they should only be providing guidance that the operator may choose to follow or ignore (much as the operator today may choose to follow or ignore the manufacturer’s TBO recommendations).

      I do NOT agree that “any IA should be capable of determining” the condition of the engine. I deal with IAs every day who want to tear down a perfectly good engine because they find a trivial amount of metal in the oil filter. In my experience, many (perhaps even most) IAs overreact to any abnormal indication for fear of civil liability. They are simply terrified of being sued, and that terror clouds their judgment. One told a client of mine this week, “I don’t want my signature to be the last one in your logbook when you fall out of the sky. I’m not giving you a logbook entry unless you agree to have the engine torn down.” (This engine suffered detonation damage to the #2 cylinder. We’ve had expert verification that there’s nothing wrong with the rest of the engine beyond the #2 cylinder and piston.) Sadly, most owners just capitulate under this kind of pressure. (We’ve already arranged to bring in another less gun-shy mechanic willing to change the #2 cylinder and piston and sign off the engine as airworthy.)

      I don’t like mechanics pushing owners around any better than I like manufacturers pushing owners around. The owner has primary responsibility for airworthiness (91.403), and in my view the owner should always be the one who calls the shots. (This will be the subject of an upcoming AOPA Opinion Leaders Blog post.)

  9. I’m assuming that the primary advantage of ECi offering a complete engine is to provide an affordable alternative to Continental or Lycoming and, if so, the price contrast is never really fleshed out in the discussion. Condition monitoring is an interesting concept and sounds attractive if it will not be used to mandate overhauls and other maintenance for having reached a potentially arbitrary parameter.
    On the other hand, I would not necessarily be frightened off were the engines to be approved under the conventional process with the limitation of a substantially reduced TBO. As I see it, the reduced TBO would be a perceptive matter affecting marketing and perhaps aircraft value and no more an expense or reliability issue for the buyer than with any other engine. Additionally, if a new engine could be procured from ECi for a cost not significantly greater than the cost of overhauling the other brands, I would prefer the new motor. The matter would further resolve itself as recommended TBO’s are incrementally increased as the engines are proven to the FAA’s satisfaction.
    Again, this is based on the assumption that the ECi engine represents a less expensive option.

    • I have no idea what the selling price of a certificated Titan engine would be, and I’m not sure ECi knows yet, either. I’m sure those decisions will be made as the engine nears certification. That could be awhile, obviously.

      I do know that the Titan EXP engines have been a huge hit in the E-AB community, particularly with the RV folks. I’m not sure it’s because they’re cheaper than Lycomings (although I imagine they are), but because they have numerous performance improvements compared to Lycomings (greater displacement, higher compression ratio, cold induction system, improved fuel injection, lightweight magnesium oil sump, etc.). I do not get very involved with non-certificated airplanes, or their engines, and there are undoubtedly many who are much more knowledgeable than I am on this subject.

  10. How is it that I can operate a pair of BMW/RR BR-710’s “on condition”, as a part 91 operator, and yet I can’t do the same with my piston powered aircraft? Arguably, the piston engines are even more “modular” in nature, with major components easily replaced in the field.

    • Unless you’re a Part 135 operator, you CAN operate your piston aircraft engine “on-condition.” The manufacturer’s recommended TBOs are just that: recommendations. You are free to ignore them. Both engines on my personal airplane (a 1979 Cessna T310R) are at 205% of TBO and counting…

  11. Sounds good, but very expensive, just in the pilot/owners area of all the extra avionics/instrumentation needed, to support the requirements. Add to that the cost and time getting an approved STC for a particular aircraft, especially some of the older ones in the present fleet. Then the additional extras needed by the a&p/IA for collecting the data and photos required, as part of this program.

  12. I wish ECi all the best. It continues to be ridiculous that government gets in the way of progress. The FAA is a prime example when it comes to aircraft and how new technology has not been easily adapted to this industry.

  13. Andrew Roberts

    May 18, 2014 at 3:06 pm

    They need to get these engines in non-commercial aircraft. I would have no problem buying one of these. Just put a warranty on it to 2000 hours. Pilots who don’t have to follow the replace at 1000 tbo won’t have a problem running it to two, especially if the manufacturer warranties it to 2000.
    If the product is as good as a claim it to be, this shouldn’t be a problem.

    • That’s the first thing I said to Jimmy Tubbs: Why would a Part 91 operator care what the TBO is? But apparently thinking like yours and mine are in the minority, and ECi’s marketing folks have done enough market research to learn that a 1000-hour TBO would be a deal-killer. There are just too many aircraft owners and mechanics out there who have drunk the TBO KoolAid and believe that TBO actually means something. (Sigh.)

  14. Great information…..As an ATP/CFI/A&P/IA I believe the owner should be involved in the annual inspection. Learn to fly right and learn to care for the aircraft is the best defense against an accident or incident.

    Unfortunately in this litigative world one has to protect one self from a law suit. My practice is to have an extensive check list for the annual and on returning and engine back to service I always include a certain statement on my squawk sheet….ENGINE RETURNED TO SERVICE BASED ON CONDITION. MANUFACTURER OVERHAUL RECOMMENDATION IS… (12 YEARS OR 2000 HOURS) I HAVE RECOMMENDED TO THE OWNER TO OVERHAUL THIS ENGINE BASED ON MANUFACTURERS RECOMMENDATION.

    Sounds silly? maybe, but it is my duty to inform the owner that the manufacturer recommends this overhaul cycle.

    In the real world as an instructor, I fly behind 35 year old engines with 1600 hours on them. Sometimes one wonders about condition. We are human and make mistakes, but the FAA is there to protect the public (it is said) and they will violate anyone in a heart beat that is involved in an incident or accident. FAA BTW, is a reactive agency and finds problems after the fact. The reason for Instructors and Mechanic IA’s is to help protect the flying populace against themselves. I give advise and help to any one that cares to do the right thing .

    Thanks again for what you do Mike………..

    Richard Wyeroski, former FAA Safety Inspector Operations GS/13-4

    • Richard, that does not sound silly at all. In fact, it’s exactly what I recommended in an article I wrote titled “A Mechanic’s Liability” that discusses the daunting risk of civil litigation faced by mechanics. I recommend that mechanics provide aircraft owners with “CYA letters” stating that the mechanic recommended compliance with a laundry list of manufacturer recommendations (TBOs, service bulletins, etc.) despite the fact that as a Part 91 operator compliance is not required by regulation, and that the owner declined to have the work performed as recommend. The CYA letter should be signed by the mechanic and countersigned by the owner, and each should keep a copy. That way, the mechanic is protected and the decision making is squarely where it belongs, on the shoulders of the aircraft owner.

      Civil lawsuits against shops and mechanics have exploded since 1994 when GARA was passed by Congress, shielding aircraft manufacturers from product liability on aircraft more than 18 years old (i.e., most of the GA fleet). This didn’t make the air crash lawsuits go away, it just changed the defendants from the deep-pocket manufacturers to shallower-pocket defendants like shops and mechanics. The result has been an explosion of “defensive maintenance” that is just as much a scourge to GA as “defensive medicine” is to healthcare.

      The solution is for aircraft owners to own up to their regulatory responsibility for maintenance decision making and to master the fine art of knowing when to say “no” to mechanic recommendations, sorting out the difference between recommendations based on safety and regulatory necessity and those based on liability-avoidance. When aircraft owners abdicate their decision making responsibilities to their mechanics, they should expect that the mechanics will make decisions based at least in part on the mechanic’s own liability concerns, that that can greatly impact the owner’s cost of maintenance.

      Thank you for your kind words, Richard, and your participation on this blog. –Mike

  15. I’m on a quest for a good maintenance advisory service that is dependable, since Mike’s Savvy crew certainly isn’t and they cost us a lot of money when they screwed up. He gets free advertising here and that’s how we found and bought into Savvy, but beware, the savings they promise go the other way when they drop the ball and leave you in a pinch to pay the extra charges for more expensive and expedited parts that they should have taken care of days earlier.

  16. The BR-710 engines on our G550 are operated “on condition”. The requirements are simple, starting at 3000 hours (if I remember correctly) an extensive borescope and visual inspection is required. Along with lifetime oil samples and lifetime engine trend monitoring. Our aircraft is operating well into the timeframe where the engines would normally have been removed. With no internal cracks, no flaws, no additional vibration, and new engine levels of performance.

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