Firsthand Look: TCM Crankshaft Inspections

"Hey,Mike! Looks like there may be a problem with Continental crankshafts."

I looked up from my Makita, with which I'd been reinstalling inspection plates at theend of a grueling month-long annual on my Cessna 310. It was Monday April 5th, if memoryserves, and the voice from the open door at the top of the stairs leading down onto thehangar floor belonged to Steve Ells, technical representative and magazine editor for theCessna Pilots Association (CPA). As owner of two big-boreContinentals, I gave Steve a look that told him that he had my undivided attention.

Steve went on to say that he'd received a phone call from a CPA member who said he'djust been contacted by TCM Director of Field Sales and Service, Bill Blackwood, and askedto remove two cylinders and connecting rods from the factory-rebuilt IO-520 engine on hisCessna 210 and have the aft side of the #2 crankshaft cheek inspected with dye penetrant.The owner was told that six low-time new and reman 520- and 550-series engines hadsuffered broken crankshafts, and that his crankshaft had been manufactured on the same dayas one of the failed ones, causing TCM to ask that it be checked. As soon as the phonecall from Blackwood ended, the owner called CPA for a second opinion on whether or not heshould consent to TCM's unusual request.

Steve called a few engine shops to find out what they knew about these crankshaftfailures, then called Blackwood to confirm that what the owner had told him was true. Itwas. Blackwood said that he'd phoned 127 owners of engines with crankshafts that had beenmanufactured within a day of the manufacture date of the six failed cranks — most ofwhich had been built in May or June, 1998 — and asked that the owners submit to avoluntary inspection at TCM's expense.

The next day, I had a quick informal conference with Steve and CPA executive directorJohn Frank, and we all agreed that this was an important story that all owners of big-boreContinentals needed to know about. It was immediately apparent to us that unless TCM wasable to find out quickly why the six cranks failed, they'd have no alternative but towiden the net and call for the inspection of more engines. They'd been very lucky so far:Only one of the six crankshaft failures had resulted in a crash, and that crash involvedonly minor injuries. But the next failure could prove fatal. TCM would have to movequickly.

Our job, as we saw it, was to get the word out to owners. On Thursday morning, April 8,CPA devoted most of its weekly CPA ATIS email newsletter to the TCM crankshaftsituation. I decided to make this the lead story in AVwebNewsWire and AVflash which went out to 100,000 aviators in the wee hours ofMonday morning, April 12. We advised all owners of Continental -520 and -550 engines withcranks manufactured in 1998 to check their propeller flanges for the manufacturer's datecode, and to be prepared for TCM to expand the scope of the inspections. On Tuesday, weobtained a FedExed copy of TCM Special Service Instruction SSI 99-1 containing the fulldetails of the dye penetrant inspection procedure. We immediately scanned and OCR'd it,converted it to HTML, and put it up on the Web. (TCM's own Web site didn't have a syllableabout this yet.)

Things started happening at warp speed after that. By mid-week, we learned that TCM waspretty sure it had found the cause of the failures: a faulty tool mounted on a 5-tonhydraulic press that was used to install counterweight hanger bushings into thecrankshafts. The bad news was that this tool had remained in use until late December,1998. Clearly, the number of crankshafts that might have been compromised was going to bea whole lot more than 127.

By week's end, I received word that TCM would be issuing a Critical Service Bulletinrequiring inspection of all big-bore crankshafts manufactured during 1998, and that theFAA would follow suit with an Airworthiness Directive. On Saturday morning, I spent morethan an hour on the phone with John Barton, TCM's Senior Director of Engineering, askingquestions and taking notes on the scope and expected details of the upcoming CSB and AD.Barton was entirely candid and forthcoming with me — a refreshing surprise, given theobvious delicacy of the situation — and offered straight, detailed answers to all of myquestions. It was obvious to me that he was as interested in getting the word out toowners as I was. Nobody wanted to see another in-flight crankshaft failure.

I worked feverishly through the weekend on a long,detailed lead news story for AVweb NewsWire and AVflash. By Mondaymorning, April 19, the aviation community learned about the details of CSB 99-3 daysbefore TCM issued it. In addition to expanding the scope of inspections to a full year'sworth of crankshaft production and adding 470-series engines, TCM had decided that dyepenetrant inspection wasn't adequate, and would be calling for ultrasonic testing (UT) ofthe crankshafts — a procedure that required special test equipment and highly-trainednon-destructive testing (NDT) technicians to perform.

This was turning into a very big deal indeed. Initial estimates were that 2,200 engineswould have to be inspected. Later, TCM realized that reconditioned crankshafts used inreman engines would have to be included, too, since those were re-bushed using the sametooling that had caused the problem. By the time CSB 99-3 hit the streets at the end ofthe week, the number of affected engines had grown to more than 3,000. For those with lessthan 300 hours time-in-service — which was most of them — compliance time was just 10hours.

Having ordered the inspections and offered to pay for them, TCM was now faced with amonumental logistics challenge. For one thing, they needed to find out where the 3,000affected engines were located and who owned them...fast! The company rushed to set up aspecial toll-free telephone hotline (1-888-200-7565) staffed by personnel armed with a"CSB 99-3 Contact Form" and instructed to solicit all the pertinent informationfrom each owner who called, and to enter the information into a computer database. Theyalso put up an electronic version of the contact form on the TCMlink Web site. AVwebpublicized both the number and the URL even before CSB 99-3 was officially released, andthe calls and e-forms started pouring in.

Unfortunately, many owners who called the hotline came away frustrated. They werelooking for answers about when and where their inspection could be accomplished and howsoon they could get back into the air. The people at the other end of the phone didn'thave any answers for them — no inspection plan or schedule yet existed — and all thehotline people could do was to take the owners' information and promise someone from TCMcustomer support would get back to them. In some cases, the owners were promised thatthey'd receive a callback within a few days, and when that didn't happen, the owners wereunderstandably furious.

(Once upon a time, back when I was young and foolish, I used to take telephone messagesfor my wife by saying, "I'll have her call you back as soon as she returns."But, as I grew older and wiser, I learned to say, "I'll let her know youcalled." Never make promises you can't keep.)

Meanwhile, in the TCM executive offices, top management was just coming to grips withthe daunting task of getting all the inspections done in a reasonable amount of time. CSB99-3 required that the UT be carried out by a Class III NDT technician who had gonethrough special training by TCM in the procedure. TCM had only a handful ofsuitably-qualified technicians in-house. They contracted with one of the world's largestNDT firms — Law Engineering, Inc. — to provide additional inspectors. But a week afterCSB 99-3 was issued, TCM had only been able to come up with ten qualified and trainedinspectors on such short notice. When they divided 3,000 engines by ten inspectors, andtook into account that those inspectors would be spending at least half their timetravelling around to where the engines were, the near impossibility of the task started tosink in. Until that point, TCM had been so preoccupied with figuring out whatneeded to be done that they hadn't had time to deal with the question of how to doit.

On April 26, just days after TCM issued CSB 99-3, AVwebNews carried the following advice to owners:

This advice proved to be spot-on. In the course of the next few weeks, I receivednumerous emails from AVweb subscribers who had followed our recommendation andgotten their engines inspected within a week or so. Most passed the UT and were back inthe air in short order. Those that didn't at least had the benefit of having "firstdibs" on the fast-dwindling supply of replacement crankshafts. In contrast, ownerswho were not tuned into the Internet for the most part remained clueless until weeksafterwards, when they received a mass-mailed notice from TCM alerting them to CSB 99-3.

Fastforward to Friday, May 14.

This was the day that TCM had scheduled an inspector to come to my home airport of Santa Maria, Calif. (SMX),to inspect three engines at one of the local FBOs, Aero-WestSpecialties LLC. The three aircraft — two Beech Bonanzas (an F33 and an A36) and aCessna 414A twin — were prepped and ready. The owner of the FBO — Michael Lentini — andhis lead A&P/IA — Ron Martinson — were standing by in eager anticipation, as werethe three aircraft owners. John Frank, executive director of the Cessna PilotsAssociation, was there to watch the goings on. And of course, I was there — armed withreporter's notepad and digital camera. After being totally immersed in reporting thissituation for more than a month, there was no way I was going to miss the chance to seethe CSB 99-3 inspection process in the flesh.

Guess what? The TCM inspector never showed up. To make matters worse, nobody from TCMbothered to call the FBO to tell them that the inspector wouldn't be coming! There we were— FBO personnel, aircraft owners and journalists — all twisting slowly in the wind, soto speak.

After lunch, I listened while FBO owner Lentini made several increasingly frantic phonecalls to Mobile to find out what was going on. Eventually, Lentini reached Bill Blackwood,who told him that the reason the inspector didn't arrive on-schedule was that when he gotto his previous inspection location in Southern California, he discovered a lot moreengines there prepped for inspection than he'd been told to expect by the scheduling folksin Mobile. According to Blackwood, a bunch of owners, noting TCM's published inspectionschedule (and heeding AVweb's advice to go to a major metropolitan area shop),simply flew their airplanes in as unscheduled "walk-ins" and the inspector wasinstructed to stay and finish them all up. Lentini asked when he could expect the threeengines to be inspected, and was told, "we'll try to have someone there Monday."Lentini said that was unacceptable, and eventually persuaded Blackwood to arrange for theinspections to be done on Sunday instead.

As promised, Ken Howard of TCM and David Smith of Law Engineering arrived at SMX onSaturday night, checked into the Airport Hilton, and were at Aero-West Specialties at 0830Sunday morning. Smith, a Class III NDT technician, was to perform the actual UT procedure,while Howard would handle the paperwork and sign off the inspections on behalf of TCM.Howard had another purpose as well — as TCM's service rep for Australia, he had beentasked by TCM to set up the CSB 99-3 inspection program for the Pacific Rim, and this waspart of his on-the-job training.

By the time I arrived at Aero-West Specialties at 0900, they'd already completedinspecting the first engine — an IO-470 on the Beech F33 — and found no problems. Theywere just starting to inspect the right engine of the Cessna 414A, a TSIO-520-NB. KenHoward shined a flashlight onto the #2 crankshaft cheek and muttered the Australianequivalent of "uh oh." Each of us took turns as Ken patiently showed us where tolook. Sure enough, a mark was clearly visible dead-center on the corner of the cheek. Kenexplained that the presence of a visible mark did not necessarily mean that the crankshaftwas rejected. Only the UT — which would measure the depth of the damage — coulddetermine that.

At this point, NDT tech David Smith took over. His first step was to recalibrate theultrasonic test equipment, something that is done immediately before every test. To dothis, he used a specially-prepared steel bar that had a calibrated .020-inch nick on onecorner. (.020 is approximately the depth of the nitride-treated outer layer of thecase-hardened crankshaft.) The UT box was adjusted so that the ultrasonic echo from the.020-inch nick occupied exactly 100% of the height of the unit's oscilloscope-like displayscreen. Then, a reference line was programmed into the unit at the 30% level, representingan indication of about .006 inches. That, Smith explained, was the prescribed go/no-gothreshold for the CSB 99-3. An UT indication of 30% of more would cause the crankshaft tobe deemed unairworthy.

Smith deftly manipulated the ultrasonic probe into position on the #2 cheek while hewatched the UT readout, and the rest of us jockeyed for position to look at it over hisshoulder. As the waveform stabilized, Smith muttered the North Carolina equivalent of"uh oh" as the reading settled down at 47% — a definite failing grade. Howardexplained that this did not mean that the crankshaft was actually cracked. In fact, TCMhas not found actual propagating fatigue cracks in any of the 1,000 crankshafts it hasinspected so far under CSB 99-3. Nevertheless, the 47% UT indication revealed that thenitride case of the crankshaft had been damaged beyond the maximum acceptable limitsestablished by TCM Engineering, and would have to be replaced.

Smith proceeded to test the other three locations on the crankshaft where damage couldhave occurred, and they all came up clean. But this was little consolation. The 414A'sengine would have to be removed, crated up, and shipped to Mobile for a crankshafttransplant. After installing the new crank, TCM will run the engine in a test cell, thenship the engine back to the FBO for reinstallation in the aircraft Ken Howard estimatedthat turnaround time would be approximately three weeks. This process is not considered tobe an overhaul or rebuild — it will appear in the engine logbook as a repair, and theengine will retain its time-in-service. However, TCM is providing a six-month warrantyextension, so that for all intents and purposes, the engine's warranty will start overagain from scratch.

The group moved on to the third engine, an IO-520 in an A36 Bonanza. Once again, Kenpointed out an area of visible damage on the #2 cheek. While not nearly as easy to see asthe damage on the twin Cessna's crank, it was readily identifiable now that we knew whatwe were looking for. David fired up the UT machine, and announced that this engine wouldhave to go back to Mobile as well.

Shocked by the fact that two of the three crankshafts had flunked the UT exam, I askedKen Howard whether this was typical. "Heavens no," he said. He showed me hispersonal inspection log for the past couple of weeks. Including the three just completed,his logs revealed 56 engines inspected and six flagged for return to Mobile — a failurerate of about 11%. This fell right into line with the 10% to 15% figures I'd been hearingfrom various sources.

Subsequently, on May 20th, John Barton furnished me with a hot-off-the-press copy of aninterim CSB 99-3 status report that TCM had prepared at the request of the FAA:

If this 13% flunk rate continues, it means that about 400 engines will ultimately getshipped to Mobile by the time the CSB 99-3 inspection program is over. Although Iunderstand that the TCM factory is now running seven days a week, two shifts a day, tokeep up with the additional workload, it seems pretty obvious to me that the disassembly,reassembly and testing of those engines are almost certain to consume most of the finalassembly and test cell capacity of the factory for the next few months. Furthermore, thecrankshaft replacements will consume the equivalent of nearly three months' worth of newcrankshaft production.

The result is almost certain to be a critical shortage of new and factory rebuiltengines, as well as a shortage of replacement VAR crankshafts for field overhaul shops.Keep in mind that big bore TCM engines equipped with older airmelt crankshafts arerequired to change to a new VAR crank at major overhaul (or any other time the case issplit).

These second-order effects of CSB 99-3 are already being felt. For example, I spoke toan overhaul shop last week that had an IO-520 engine from a customer's Cessna 210 that hadsuffered a prop strike. The crankshaft had been damaged by the sudden stoppage, so theshop ordered a replacement crankshaft from TCM. While the new crankshaft was still intransit from the factory to overhaul shop, the shop received notice from TCM that thecrank had a 1998 manufacture date and was being recalled. The shop phoned TCM to order yetanother crankshaft for the C210 engine, and was told by the TCM sales representative toexpect delivery "in about 120 days...I guess." So the aircraft owner — whoseengine was not directly affected by CSB 99-3 — is looking at another four months ofdowntime. There have to be dozens, perhaps hundreds, of other owners in similarsituations.

The anticipated shortage of VAR cranks and new engines is also bound to depress themarket for used aircraft that have high-time Continental engines and non-VAR cranks, atleast temporarily. I recently exchanged email with one prospective purchaser who passed upwhat would otherwise have been a good deal on a V-tail Bonanza with a run-out engine, inpart because of anticipated problems getting a VAR crankshaft.

It's not just crankshafts that are in short supply, either. Remember the two enginesthat flunked inspection in Santa Maria on April 16? Well, it's a week later now and thoseengines are still not on their way to Mobile. Why? Because it seems that TCM has run outof shipping crates! Not surprising in the slightest, if you think about it. As usual, thechain is only as strong as its weakest link. From an owner's point of view, it doesn'treally matter whether it's crankshafts, gasket sets or shipping crates that areunobtainable. The result is the same: AOG (airplane on ground).

Meantime, the owner of the F33 that passed the UT inspection still doesn't have hisplane back, either. Turns out that TCM provided the FBO the incorrect gasket set, and whenthe FBO called Mobile to complain, they received another gasket set via overnightexpress...also the wrong kind! (The F33 has an older-style engine, and the newer-stylegaskets don't fit.)

Trust me, folks. The situation is bound to get a lot worse before it starts getting anybetter. It's gonna be a long, hot summer.

The good news is that everyone at TCM seems to be going the extra mile to try to makethings right, albeit under very difficult circumstances. With about one-third of the CSB99-3 inspections done and two-thirds left to go, TCM customer support finally seems to begetting a handle on the scheduling and logistics of moving the inspectors around. Theinspector force itself has grown from 10 to 26 — which helps a lot — and another 14inspectors are due to come on stream soon, many of them slated for assignment tointernational regions. For customers outside the U.S., the inspection program is about tobegin in earnest, and every indication is that the people involved in coordinating it(such as Ken Howard in the Pacific Rim) have learned a great deal from the mistakes madeduring the early weeks of the U.S. inspection effort, and are unlikely to repeat themoverseas.

AVweb will continue to do everything possible to keep you informed as theinspections and crankshaft replacements continue, and with them the inevitable collateralproblems. We urge owners to be as patient and understanding as possible until this ordealis over and the affected aircraft are back in the air. There'll be plenty of time forfinger pointing and Monday morning quarterbacking later.