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Borescope Ascendancy

by | May 1, 2017 | ,

Time to topple the venerable compression test? The differential compression check has been a mainstay of piston aircraft engine maintenance for the last 80 years. Like anything else in aviation that’s been around for a long time, various Old Wives’ Tales (OWTs) have evolved about the procedure, passed on from journeyman mechanic to apprentice, and later taught in A&P schools and documented in various textbooks and advisory circulars. Ask your mechanic why he performs a compression check a certain way or interprets the test results as he does, and if he’s honest he’ll probably answer, “That’s the way I was taught to do it and that’s the way I’ve always done it.” One pervasive OWT has it that compression readings in the high 70s are excellent, in the low 70s are good, in the high 60s are marginal, in the low 60s are poor, and anything below 60/80 is unairworthy. Another widely accepted OWT is that an engine with compressions in the low 60s is a “tired engine” that will not put out full rated horsepower. Both are dead wrong. More than three decades ago, Continental Motors issued a service bulletin (M84-15) debunking the first of these OWTs by establishing […]

Field Approvals

by | April 1, 2017 | ,

Do you really need the FAA’s blessing to modify your aircraft? A Bonanza owner wanted to power his portable GPS and his iPad simultaneously in flight, so he asked his avionics shop to install an extra cigar lighter socket on the panel. He was told that doing so would require preparing an FAA Form 337 and obtaining a Field Approval from the local FSDO, and he was warned that this might be time-consuming and costly. Later, the owner made the same request of his A&P mechanic, who said “no problem,” installed the socket and signed it off with a simple logbook entry.  Who was right, the avionics shop or the A&P? A Cessna 210 owner had his A&P install a gear mirror on the underside of the left wing so he could visually check that his landing gear was down and locked. Several years later, during an annual inspection, an IA told the owner that there was no Form 337 for the mirror and that it would have to be removed before the IA could sign off the inspection as airworthy. The IA indicated that the only alternative would be to ask the local FSDO to send out an airworthiness […]

Buy…or Walk Away?

by | March 1, 2017 | ,

Thoughts about when to purchase and when to pass. Who among us hasn’t spent hours looking at Trade-A-Plane or Aircraft Shopper Online looking for that perfect low time airplane with a fresh engine overhaul, new paint and interior, great avionics, and a bargain price? Dream on! Common sense says if you find one, there’s probably a good reason that it’s underpriced … like maybe lost logbooks, major damage history, wing spar corrosion, an expensive AD that hasn’t been complied with, or some other big-time skeleton in the closet. My aircraft appraiser friend Brian Jacobson tells the colorful story of a fellow who bought a gorgeous-looking piston twin back in the mid-1970s. It was just two years old and had less than 100 hours on the Hobbs meter, and the new owner bragged about what a “steal” he’d gotten on it. Then he tried to get the airplane added to the Part 135 certificate of his local FBO, and the aircraft’s true story came to light. It seems that at just 38 hours since new, the original owner of the twin ran it off the end of a short runway and into a water-filled drainage ditch. The aircraft sat partially submerged […]

Actionable Intelligence From Big Data

by | February 1, 2017 | ,

Comparing individual aircraft to others of their ilk. Last month, I described some interesting studies my colleagues and I have been doing with “big data” collected from digital engine monitors aboard more than 7,000 airplanes over more than a million flights. We demonstrated empirically that significantly more flights are flown with headwinds than with tailwinds, that Lycoming CHTs run 20°F hotter than Continental CHTs, and that recently designed airplanes provide better engine cooling that legacy ones (among other things). Now let’s look at how big data analysis is providing aircraft owners with specific actionable intelligence about their individual airplanes, helping them uncover problems with both hardware and operating technique. Report cards Last year, we started generating regular “report cards” to subscribers who have been uploading enough engine monitor data to the SavvyAnalysis platform to support statistically significant findings. These are emailed to the owner, and analyze a dozen or so critical flight parameters related to performance, efficiency, and engine longevity. Most importantly, it compares those parameters with all the other aircraft we follow of the same type. Here’s what such a report card looks like: This one is for a normally-aspirated Cirrus SR22. It covers 27 flights that were uploaded […]

General Aviation and Big Data – Part 1

by | January 1, 2017 | ,

Analyzing data from a million GA flights can yield interesting results. Pilots have long suspected that when it comes to headwinds and tailwinds, the deck is stacked against them.  I think the late Bob Blodget, Senior Editor of FLYING Magazine, captured how most pilots feel about this when he wrote that “we all come to the conclusion that there are always more headwinds than tailwinds; and that the headwinds are always stronger than reported or forecast, and the tailwinds weaker.”  Blodget wrote those words in 1968 and died in 1973. In his time, we could only speculate about such things. But in today’s era of computerized avionics and big data, we can prove them. My colleague Chris Wrather is a longtime friend, pilot, Bonanza owner, and A&P mechanic with a Ph.D. in operations research. Among other things, he oversees the SavvyAnalysis division of my company. Over the past four years, we’ve built a database of digital engine monitor data comprising more than a million flights flown by about 7,000 piston-powered general aviation airplanes.  Digital engine monitors typically capture data from myriad sensors between 10 and 60 times a minute. This means that for each of those million-plus flights, we’ve captured […]

Buyer Beware

by | December 1, 2016 | ,

If a plane is listed for sale cheap, there’s always a reason. “Hey Mike, this is Danny in Louisiana,” read the email. Danny is one of my clients who used to own a Cirrus SR22 and now flies a Cessna 182 Katmai STOL conversion. “Would you look at this 1965 Cessna 310I on eBay and let me know if you think a $35K price without a pre-buy would be wise. I have three buddies (plus myself) that are interested in working on twin rating, so we would be sharing the risk. Thanks in advance for your opinion.” The email ended with a link to the eBay listing. With a sigh, I braced myself and clicked the link. “This is one of the nicest twin Cessna 310I’s out there,” the eBay ad proclaimed. Let’s think about this: It’s a 50-year-old all-metal airplane, and Cessna built these aircraft with absolutely no internal corrosion proofing. This one is based in Baton Rouge, one of the highest corrosion-risk areas of the United States. It had suffered a gear-up landing awhile back, but somehow managed to avoid being declared a constructive total loss by the owner’s insurance carrier. Oh, and it had 7,639 hours on […]

Stuck in Reykjavik

by | November 1, 2016 | ,

When the pilot of a round-the-world flight found himself AOG in Iceland with electrical issues, remote diagnosis saved the day. Ademilola “Lola” Odujinrin has a passion for aviation. He’s 37 years old, resides in Nigeria with his wife and two school-age children, and was first bitten by the flying bug at age 7 when his airline-pilot uncle invited him onto an airliner flight deck (back in the days when such visits weren’t prohibited). Lola earned his private pilot certificate at age 20. A decade later, he followed in his uncle’s footsteps to become a commercial pilot flying Boeing 737s. Lola is also an overachieving athlete and adventurer, who in 2010 cycled 2,000 miles from Morocco to London in 17 days. So it was no big surprise when he announced his intention to become the first African to fly solo around the world. The aircraft Lola chose for this mission was N313CD, a 2004 Cirrus SR22 that would be “tanked” to hold enough fuel to provide endurance of 17+ hours, and equipped with survival gear, HF and sitcom radios, and a bunch of GoPro cameras. Organizing and obtaining funds for this mission (dubbed “Project Transcend”) took ten years and was fraught […]

Whoa! This Isn’t an Inspection!

by | October 1, 2016 | ,

A&Ps are trained to find things wrong with your aircraft. But there’s a time and place for that, and it comes once a year. It was the week before AirVenture 2016. Normally, I would never perform any maintenance on my trusty Cessna 310 immediately before departing on an important trip, for fear I might break something. But this time I had no choice.  The FAA had issued AD 2016-7-24 on April 26, 2016, requiring replacement of the attach hardware at both ends of the elevator trim tab push-pull rod within 90 days. As soon as the AD hit the streets, I’d ordered the required hardware, but it took a while before I received it. Once it arrived I drove to my hangar with the intention of replacing the hardware in compliance with the AD. But I was surprised to discover that there was not adequate maintenance access to the nut and bolt at the forward end of the pushrod. I couldn’t figure out how the hardware could be changed without removing the whole elevator. I checked with Paul and Phil, two A&P colleagues who I knew did a lot of Cessna maintenance, but neither had ever had occasion to perform […]

Differential Diagnosis

by | September 1, 2016 | ,

Fixing is usually the easiest part of aircraft maintenance. Figuring out what’s wrong is usually the hardest part.  By Mike Busch | A&P/IA A funny thing happened on my way to Milwaukee… It was 2013 and I was flying my trusty 1979 Cessna T310R to speak at the annual national convention of the Flying Physicians Association. My talk to the flying docs was on the subject of troubleshooting. Little did I know that my troubleshooting skills were about to be put to the test. I went wheels-up from my home base in Santa Maria, California, about 8 AM, headed for Denver’s Front Range Airport. The forecast called for thunderstorms after 1 PM, and my plan was to arrive early enough to miss them. The plan worked…although less than an hour after my arrival, a tornado touched down about 5 miles north and shut down Denver International Airport for a while. The next morning, all was calm at Front Range as I taxied out for takeoff, destined for Milwaukee’s Timmerman Airport. I was cleared for takeoff, released the brakes, smoothly advanced the throttles to the stop and started my takeoff roll on runway 17.  Uh oh! Something felt wrong. It was […]

Whom Should You Trust?

by | August 1, 2016 | ,

Before following expert advice, choose your expert with care.  We aviators are of necessity a trusting lot. We constantly trust other people with our lives, our safety, and our financial wellbeing. We trust nameless and faceless air traffic controllers to keep us from hitting anything. We trust our A&P to keep our aircraft safe to fly for ourselves and our passengers. We trust our engine manufacturer and overhaul shop to build an engine that won’t quit at night or in IMC over hostile terrain. We trust our AME to keep us out of trouble with the Friendlies in Oke City (at least until the Class 3 medical goes away, knock on wood), our broker to help us find an aircraft to buy that isn’t a lemon, our aircraft insurance agent to keep us out of hot water if something goes wrong, and the list goes on. But how can we tell if these experts upon whose expertise we depend are genuinely trustworthy? How do we know they’re giving us good advice? Should we rely on what they tell us? Should we seek a second opinion? Maybe a third? We don’t usually get to choose which air traffic controllers we depend […]

What Does “Airworthy” Mean?

by | July 1, 2016 | ,

The definition of this ubiquitous term depends on the context.  A bit over two years ago, a fellow I’ll call “Bob” bought a 10-year-old Cirrus SR22 from another fellow I’ll call “Sam.” Prior to the purchase, Bob had a very thorough pre-buy performed by an independent A&P/IA, who gave the airplane a clean bill of health. This pre-buy was so comprehensive that would have qualified as an annual inspection, but for some strange reason the IA signed it off as a 100-hour inspection instead. As a result, Bob would up having the airplane annualed just a few months later when the prior annual inspection expired.  The annual was performed at a large, well-known Cirrus Authorized Service Center—the very same service center that had performed the previous annual inspection on the airplane for Sam prior to the sale. So Bob was floored when the shop reported that all six cylinders had head cracks in the vicinity of the top spark plug holes. The shop assured Bob that Continental Motors would replace the cracked cylinders at no cost, although Bob would be on the hook for the several thousand dollars of labor involved in doing the top overhaul. Once the six cylinders […]

Is Repair a Lost Art?

by | June 1, 2016 | ,

Aircraft parts are expensive, so we really should be repairing rather than replacing them whenever possible.  When the co-owner of a 1976 Cessna 172M emailed me, she had just come from talking to her mechanic and was clearly in a state of sticker shock: “Where can I locate a used battery box for my Skyhawk without having to rob a bank? Our Gill battery (that has constantly leaked from shortly after we bought it) has caused corrosion that cannot be repaired, so we are told. Our plane is down for its annual, and apparently will remain unairworthy until this issue is resolved to the FAA’s standards. “In the past, we’ve used acid-proof paint to protect the aluminum box, and pads to soak up any leakage, but the problem has now become severe enough that the A&P says we have to replace the whole box. I thought our current one could be repaired, but according to the mechanic the bottom of the box has the stamp on it that makes it legal, and that area is damaged and needs to be replaced. “New boxes from Cessna are nearly $1,000, which we find totally ridiculous and unacceptable. What can we do? Are […]

A Mechanic’s Signature

by | May 1, 2016 | ,

What do you do if a mechanic working on your airplane tells you, “I can’t sign it off”? Dick is the maintenance officer of an 80-member flying club in northern New Jersey. The club operates several aircraft including a 2011 Cessna Skyhawk SP powered by a Lycoming IO-360-L2A engine. The engine has now reached 2,400 hours—400 hours beyond Lycoming’s published TBO of 2,000 hours. In a phone call, Dick explained to me that at the Skyhawk’s recent annual inspection, the four-cylinder Lycoming had compressions in the high 60s and low 70s. It wasn’t using much oil. The oil filter was clean, and the oil analysis report had no red flags. Most experienced A&Ps would agree that the parallel-valve four-cylinder Lycomings are the most bulletproof piston engines in general aviation, and that the Lycoming IO-360-L2A is the best of breed. If flown frequently and regularly, they often make it to 4,000 hours or more between overhauls. The flying club’s shop in New Jersey didn’t see it that way. Although the shop signed off the Skyhawk’s recent annual inspection as airworthy, they made it clear to Dick that they were profoundly uncomfortable with the club continuing to operate the engine beyond TBO. […]

LSAs: Who’s Guarding the Henhouse?

by | April 1, 2016 | ,

The new crop of factory-built LSAs are impressive and exciting, but the maintenance regulations for them are…ah…different I recently returned from the U.S. Sport Aviation Expo in Sebring, Florida, the foremost aviation event devoted to light sport, homebuilt, and ultralight aircraft. I was a first-timer at this event, having been invited by the show organizers to give a keynote address and a couple of technical forums. I accepted this invitation not because I had any expertise in this lightweight corner of the general aviation envelope—all of my prior knowledge and experience having been with standard category certificated aircraft—but because I sensed this was an exciting and rapidly growing segment of general aviation and this would be a great opportunity for me to learn about it. And learn I did. I had the opportunity to spend quality time with such legendary experts as Prof. H. Paul Shuch (LSA maintenance guru), Phil Lockwood and Dean Vogel (Rotax engine gurus), Wally Anderson (who operates Synergy Air, the nation’s largest Van’s RV build-assist center and also the manufacturer of the RV-12), and Mike Schofield (Dynon Avionics marketing manager), among others. It was like drinking from a firehose. How far we’ve come In July 2004—just […]

Inaugural GA Engine Summit

by | March 1, 2016 | ,

FAA’s Engine & Propeller Directorate meets with GA to improve how ADs are dealt with. Early last December, I had the privilege of attending a two-day meeting at the offices of the FAA’s Engine & Propeller Directorate (EPD) in Burlington, Mass., about 30 minutes’ drive northwest of Boston. The meeting was billed as the first “GA Engine Summit.” It was the brainchild of AOPA’s Rob Hackman and EPD’s Wayne Maguire. The purpose was to try to improve the relationship between the FAA and the GA community, a relationship that has been strained nearly to the breaking point in recent years by a series of draconian Airworthiness Directives (ADs) against Superior and ECi cylinders that I’ve referred to as the FAA’s “war on jugs.” The meeting was attended by a litany of FAA executives and subject matter experts from EPD, the Small Airplane Directorate (SAD), and FAA Headquarters. Industry was represented by delegations from AOPA, EAA, the Aeronautical Repair Station Association (ARSA), Continental Motors, Lycoming, Superior Air Parts, Danbury Aerospace (former owners of ECi), and a number of others. When Rob Hackman left AOPA last June, his successor Dave Oord (AOPA VP of regulatory affairs) picked up the ball, and it […]

Fear and Balderdash

by | February 1, 2016 | ,

Maintenance decisions need to be fact- and evidence-based. The current owner of the vintage J-model Bonanza emailed me for advice. He’d purchased the airplane just four months earlier with a fresh annual inspection, and was already stressing out about what to do about his engine at the next annual eight months hence. According to the owner, the airplane’s Continental IO-470 engine was the original one that had been in the airplane when it rolled out of the factory in 1958. It had been overhauled seven years later in 1965 at its published TBO of 1400 hours, and then overhauled again nine years later in 1974 when it hit TBO again. Now the engine was once again at 1400 hours SMOH, but this time it had taken more than 40 years to get there. The owner explained that the engine was using about a quart of oil every three hours, but was otherwise running strong and smooth with decent compression readings and not making metal. He wanted my opinion as to whether he should be considering a major overhaul at the forthcoming annual, a top overhaul, or no overhaul. “Considering this engine is 57 years old and more than 40 years […]

Watch Your Language!

by | January 1, 2016 | ,

When requesting maintenance, the words you use can be very important. The voice on the phone identified himself as a Cessna 182 owner—let’s call him Jim—who said he was considering overhauling his O-470-R engine and could use some advice. I asked Jim why he was considering overhauling his engine, thinking maybe it was approaching TBO and hoping to convince him this wasn’t a valid reason to tear down a perfectly healthy engine. As it turned out, this engine wasn’t yet close to TBO. Jim said his A&P recently pulled a cylinder because it had a leaking exhaust valve. With the jug removed, the mechanic discovered a badly worn cam lobe and showed it to Jim, explaining that the engine would need to be removed from the airplane and have its crankcase split in order to replace the damaged cam. The mechanic offered to do the work himself in-house (rather than send the engine out), and estimated the engine repair would come to roughly $10,000, including parts and labor. Jim agreed and authorized the mechanic to proceed. In a follow-up conversation, Jim asked his A&P whether it might make sense to overhaul the engine, given that it was already going to […]

Insurance Woes

by | December 1, 2015 | ,

When repairs are covered by insurance, it’s the owner’s job to keep things under control. By the time he contacted me, the aircraft owner—let’s call him Fred—was boiling mad. Fred had bought an airplane last year, and the pre-buy and subsequent annual inspection gave his new-to-him bird a clean bill of health. Yet even before Fred ferried the airplane to his home base, mechanical gremlins started to appear. The alternator failed. Some serious exhaust issues required repair. These and various other discrepancies started Fred thinking that perhaps the clean pre-buy and annual were a bit overoptimistic. Then ATC reported the transponder wasn’t working. Fred sent it to an avionics shop, who told him it was an old tube-type unit that was uneconomical to repair, and that he’d be money ahead installing a new transponder. Just prior to ferrying the airplane to the avionics shop, Fred discovered that the autopilot was malfunctioning. He had to pull a circuit breaker stop it from alarming. Then as he entered the pattern to land, the whole avionics stack went dark and Fred wound up landing no-radio. Fred taxied the plane to his home-field shop, but his A&P was unable to duplicate the failures, nor […]

Blame the Hardware

by | November 1, 2015 | ,

When pilots screw up, plaintiff lawyers always seem to sue equipment manufacturers. In June 2014, I posted an item to the AOPA Opinion Leaders Blog titled “The Dark Side of Maintenance.” It talked about what I refer to as “maintenance-induced failures” (or “MIFs” for short). In my blog post, I gave a bunch of examples of such MIFs—aircraft malfunctions that were the unintended result of errors during maintenance.  One of the examples I gave involved an early model Cirrus SR22 that was equipped with a Sandel SN3308 electronic horizontal situation indicator (EHSI). The Cirrus owner emailed me that he’d been plagued by intermittent heading errors on the EHSI. When I questioned the owner, I learned that he’d been suffering these problems for about three years, and that they started right after his shop performed the scheduled 200-hour replacement of the Sandel’s projector lamp. Coincidence? I’d seen this exact same problem in my own Sandel-equipped Cessna 310. It’s invariably due to inadequate engagement between the connectors on the back of the instrument and the mating connectors in the mounting tray. It’s essential to slide the instrument into the tray just as far as possible before tightening the clamp. It’s a bit […]

Tectonic Shifts

by | October 1, 2015 | ,

Changing competitive landscape in piston GA aircraft and engines. By Mike Busch I just returned from EAA AirVenture 2015 in Oshkosh, where aviation firms traditionally make major announcements. This year was no exception. One of the most significant announcements to me (as an aircraft owner and maintenance professional) was the one by Continental Motors that they had acquired the assets of Danbury AeroSpace of San Antonio, Texas.  “Danbury who?” you might ask. Actually, Danbury is a major supplier of piston aircraft engine components and experimental engines sold under the Engine Components International (ECi) and Titan brand names. ECi and Titan Engines Inc. are wholly-owned subsidiaries of Danbury. I found the Continental/Danbury announcement significant because it will result in major changes to the competitive landscape in the piston aircraft engine market. In my view, these changes will be excellent news for some aircraft owners and rather bad news for others. Some background To put this in perspective, we need to go back four decades to a time when two Texas-based companies—Superior Air Parts (SAP) and Engine Components Inc. (ECi)—first obtained FAA Parts Manufacturer Approvals (PMAs) to produce replacement parts for Continental and Lycoming engines. Prior to that time, Continental and Lycoming […]

Don’t Go Overboard

by | September 11, 2015 | ,

Suppressing the urge to overreact to and overkill problems. The Bonanza owner encountered an engine problem 11 hours after his aircraft came out of annual. He had crossed the Sierra Nevada Mountains VFR at 12,500 feet westbound enroute to the Bay Area, and was descending through 11,000 feet when he felt a bit of engine roughness. After doing an in-flight mag check and studying his JPI engine analyzer, his initial guess was that he had a bad spark plug in the #3 cylinder. But the problem got worse, and so after landing the pilot took the plane to a local mechanic and asked him to perform a compression check. Sure enough, the #3 cylinder measured 20/80 with air whistling past the exhaust valve.  Clearly the cylinder was going to have to come off and the exhaust valve and seat replaced. So far, nothing unusual here. Happens all the time. What I found interesting about this story was how the owner reacted to this burned valve episode. Here’s a brief excerpt of the email he sent to his A&P: “I think the valve may have been burning itself (or the valve seat) to a worse condition as I continued to fly.  […]

Backdoor Rulemaking?

by | August 15, 2015 | ,

Cessna gets caught with its hand in the FAA’s cookie jar. On February 10, 2014, the Cessna Aircraft Company did something quite unprecedented in the history of piston GA: It published a revision to the service manual for cantilever-wing Cessna 210-series airplanes that added three new pages to the manual. Those three pages constituted a new section 2B to the manual, titled “Airworthiness Limitations”: This new section purports to impose “mandatory replacement times and inspection intervals for components and aircraft structures.” It states that the new section is “FAA-Approved” and that compliance is required by regulation. Indeed, FARs 91.403(c) and 43.16 both state that if a manufacturer’s maintenance manual contains an Airworthiness Limitations section (ALS), any inspection intervals and replacement times prescribed in that ALS are compulsory. FAR 91.403(c) speaks to aircraft owners: §91.403(c) No person may operate an aircraft for which a manufacturer’s maintenance manual or instructions for continued airworthiness has been issued that contains an Airworthiness Limitations section unless the mandatory replacement times, inspection intervals, and related procedures specified in that section … have been complied with. and FAR 43.16 speaks to mechanics: §43.16 Each person performing an inspection or other maintenance specified in an Airworthiness Limitations section of a manufacturer’s maintenance manual or Instructions for Continued Airworthiness shall perform […]

Discrepancy Discretion

by | August 1, 2015 | ,

Who decides whether or not your aircraft is airworthy? By Mike Busch My column in the May 2015 issue of EAA Sport Aviation, titled “Fix It Now…Or Fix It Later,” discussed how to deal with mechanical problems on the road. It offered some specific advice about how pilots and aircraft owners can decide whether a particular aircraft issue needs to be addressed before further flight or whether it can safely wait until the aircraft gets back home. I considered the advice I offered in this article to be non-controversial and commonsensical, so I was quite surprised when I received an angry 700-word email from a very experienced A&P/IA condemning my article and accusing me of advising owners to act irresponsibly and violate various FARs. The author of this strongly-worded censure—I’ll call him “Damian” (not his real name)—is someone I’ve known for some years. Damian is a regional field service manager for a leading GA aircraft manufacturer, but he made it clear that the views he expressed in denouncing my article were his own and not those of his employer. It has long been clear to me that Damian doesn’t think much of my opinions about GA maintenance, and that I […]

Why I Hate Pulling Jugs

by | July 1, 2015 | ,

It’s riskier business than most owners or A&Ps realize. Regular readers of this column know how I feel about changing cylinders in the field. I hate it. Especially when several cylinders are changed at one time; this is risky business. Changing them all (the so-called “top overhaul”) is even riskier. In my column in the June 2014 issue (“Cylinder Work: Be Afraid”), I explained the nature of the risk: Changing cylinders involves messing with the ultra-critical clamping force (“preload”) of critical threaded fasteners. And it’s extremely difficult to ensure that the correct preload is achieved when tightening those fasteners with a torque wrench, even if the manufacturer’s procedures are followed to the letter. A couple of recent NTSB Probable Cause reports illustrate this issue rather vividly. Both of these reports were literally hot off the press as I’m writing this column. I offer them here without comment, because they speak for themselves.  Spun bearing, broken crankshaft NTSB Identification: ERA14LA193Accident occurred: Friday, April 11, 2014 in Louisa, VAProbable Cause Approval Date: 04/27/2015Aircraft: CESSNA U206G, registration: N156SAInjuries: 1 Serious, 1 Minor. Narrative: The pilot reported that, during the flight before the accident flight, he noted that the oil pressure was slowly fluctuating, so he chose to change the […]
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