NTSB Faults Aircraft Owner for Running Engine Past TBO

Aircraft engine manufacturers recommend that owners overhaul their engines when the engines have accumulated a set number of flight hours. Depending on the make and model, the "Time Between Overhaul" ranges from 1200 to 2400 hours. No regulation requires the general aviation aircraft owner to comply with the manufacturer's recommended TBO. As far as the FAA isTeledyne Continental Engine concerned, the owner is free to operate the engine indefinitely, as long as a certified mechanic has signed off the engine as airworthy within the preceding 12 months. And given recent advances in engine diagnostic equipment, more and more owners are feeling comfortable "busting" TBO.

I wrote about the practice years ago, in a post entitled "Running Past TBO: Smart Economics or Owner Negligence?" The NTSB recently came down on the side of "owner negligence," at least in the case of a Cirrus engine that was operated past Teledyne Continental's recommended 2000 hour TBO.

The National Transportation Safety Board determines the probable cause(s) of this accident to be: The inadequate servicing and maintenance of the engine and the airplane owner and maintenance personnel's disregard of the manufacturer's recommended engine overhaul schedule and service bulletins, which resulted in an in-flight internal failure and seizure of the engine.

In that case, the engine failed at 2978 hours.  The NTSB also faulted the pilot for flying the aircraft with only 5 quarts of oil on board, instead of 6 quarts as recommended by the manufacturer.

Fortunately, no one was hurt. But an owner should think twice about running past TBO, regardless of whether an FAA-certified mechanic has pronounced the engine airworthy.


$26 Million Jury Verdict After Lycoming Refuses to Turn Over Documents

A jury in Washington state handed down a $26 million verdict against Avco Lycoming as a result of a fatal Cessna 172 crash that killed three people in 2008.  The  jury's award included $6 million in punitive damages, designed to punish Lycoming for consciously disregarding the safety of the flying public.

It's the second time a jury has slammed Lycoming with punitive damages for its carb floats. In 2010, a jury awarded $89 million, including $64 million in punitive damages, as a result of 1999 Cherokee 6 crash that killed four and injured one.

This case, however, was a bit different. It was the judge who ruled that Lycoming was responsible for the crash before the case ever reached the jury.  All that was left for the jury to decide was how much to include in its verdict.  The judge ruled against Lycoming because it refused to turn over relevant documents in the case.  Apparently, the documents were so incriminating that Lycoming felt it was better to suffer a certain jury verdict than to allow the documents to see the light of day. 

[I]n December 2005, Lycoming participated in a series of emails discussing the leaking Delrin Float issue, none of which Lycoming produced during discovery. The series of emails informs Lycoming of the significance of the Delrin float leaking problem. In the emails, Lycoming employees state that it is clear that hollow plastic carb floats can leak, allowing fuel to enter the interior of the floats. The emails reflect that there was also a recent inflight [engine] stoppage. The email also recognized the danger of discussing the defects in writing: “It is too bad that we have to answer in writing on such a touchy issue.”

Plaintiffs asked Lycoming to turn over the rest of the emails on the subject, including those that went to upper managment.  The emails would have been important evidence that Lycoming knew the floats leaked and could cause engine failure. But Lycoming refused. So the court ordered Lycoming to turn them over. Lycoming still refused. 

Lycoming's  willful and deliberate refusal to follow the court’s order prevented plaintiffs from proving their case. So the court did the only thing that was fair and ruled that the floats were defective and caused the accident.

The Judge's order is an interesting read. 

Judge's Sanctions Order Against Lycoming

The "Impossible Turn" and Three Mooney Crashes in Two Weeks

Three Mooneys have crashed in two weeks.  Each aircraft crashed on takeoff.  Sadly, seven people were killed.  Two of the accidents may have involved the "impossible turn."

First Crash: On July 5, a 1974 Mooney M20F (N7759M) crashed shortly after taking off from Watsonville, California.  All four aboard were killed. 

Second Crash: On July 17, a nearly identical Mooney M20F (N3524X) crashed taking off from Winslow-Lindbergh Airport in Arizona, killing two aboard.  

At first glance, the Watsonville crash and the Winslow crash seem eerily similar.  The same model aircraft was involved in each.  Each crashed just moments after takeoff. 

But the two accidents are entirely different. The Watsonville crash is consistent with the pilot climbing too steeply to avoid a fog bank. There doesn't appear to be any evidence of an engine problem, at least at this point. Rather, as the pilot pitched the nose up, his airspeed bled off, and the wings (not the engine) stalled.  According to one witness:

He was heading toward the coast and tried to climb . . .From the time he took off, he was going too steep, too slow. ... He spun to the left and you can see where the impact was.

In contrast, the pilot in the Winslow crash appears to have attempted to turn around and glide back to the runway after his Lycoming engine quit.  

A Mooney departed then called with engine problems [saying he was] returning to the airport [from the] opposite direction. My friend circled giving the Mooney the right of way. .  Later he asked the Mooney for a position, no response to a couple of calls. He circled for a while longer then landed. Rolling out he saw the Mooney off the departure end of the runway on its back. He said it looked like the typical return to the airport stall spin accident.

The attempt to return to the airport after an engine failure is often called "the impossible turn," because it so frequently ends in the aircraft stalling during the turn and spinning in, with fatal results.

Plots are trained never to turn back to the runway after an engine failure unless they have adequate altitude.  Instead, land straight ahead, or slightly to the right or to the left.  Better to land in the trees, but under control, then lose control of the aircraft and spin in.  While a crash landing in rough terrain may result in serious injury or even death, spinning into the ground is almost always fatal.  Losing control of the aircraft after engine failure must be avoided at all costs. Unfortunately, the temptation to try the "impossible turn" and make it to the runway can be irresistible.

This video shows a Mooney pilot attempting the impossible turn after engine failure near Sacramento, California in 2009.  Both he and his passenger were killed when the aircraft spun in.



Third Mooney Crash: Finally, on July 18, a 1979 Mooney 20K (N777CV) crashed at Augusta Regional Airport while taking off, killing the pilot and sole occupant, a Mooreville doctor. That aircraft also came to rest within the airport boundaries.  It appears this pilot also experienced engine failure, and also may have attempted to turn back to the airport, stalled, and spun in.  Too early to tell.

Is the Robinson R66 Helicopter Safer than the R44?

Some pilots refuse to fly piston-powered helicopters, insisting instead on turbine-powered machines.  Turbine engines, their argument goes, are much less likely to fail in flight than piston engines. Though more expensive to purchase and to operate, the reliability of turbine-powered helicopters makes them safer than their piston-powered counterparts.

Does that mean the new Robinson R66, with its Rolls-Royce turbine engine, will be a safer helicopter Robinson R66 (Turbine engine)than Robinson's R44, with it's Lycoming piston engine? 

Not according to Robinson.

In fact, for years Robinson has taken a contrarian view, suggesting that pilots are in fact safer in piston-powered helicopters.  Though the large turbine engines used in airliners are incredibly reliable, the small turbine engines used in helicopters are not.  According to Robinson, accident statistics favor piston helicopters. 

Tim Tucker, a Robinson factory pilot, caused a stir when he published the data supporting that argument in a 2003 issue of Rotor and Wing magazine.  Unfortunately, his article, ("Turbine Reliability: Fact or Fiction") is no longer available on the internet (or at least I can't find it). But Robinson R44 owner and flight instructor Philip Greenspun sums up the substance of  the argument pretty well:

Turbine engines have a reputation for extreme reliability, but physically small turbines, such as those that go into low-power helicopter engines, are subject to a lot of thermal stress and are not nearly as reliable as the turbines in an Airbus. Piston engines have a reputation for unreliability, but that was earned when the engines were operated at 100 Robinson R44 (Piston engine)percent power. The R44 is a demonstration of the most reliability that you could ever get from a piston engine; the Robinson R66 and similar light turbine helicopters demonstrate the least reliability that you could ever get from a turbine engine. . . 

The Robinson factory stops short of saying that the turbine engine makes its new R66 more dangerous than the R44.  But it's not saying that it makes it any safer either. Deftly avoiding the issue, the company president told AOPA Pilot magazine (December 2010 issue): 

The decision to use a turbine engine really had nothing to do with reliability.  Data has shown the Lycoming 0-540 installed in the R44 to be extremely reliable.

But If Robinson believes small turbine engines are less reliable that the piston engines, then why is Robinson introducing a turbine-powered helicopter at all? 

According to Robinson, the market wants a helicopter with improved performance at high altitude and a better power-to-weight ratio.  It also wants a ship that can use jet fuel, since avgas is in some parts of the world becoming harder to come by. Only a turbine-powered helicopter can meet those demands.

Fair enough.  Just don't think that shelling out the big bucks for the R66 ($790,000 for the R66 vs. $415,00 for the R44) is going to buy a greater extra margin of safety.  In fact, if you believe what Robinson has been saying about small turbine engines for the past 10 years or so, the R66 should prove to be less reliable, and thus less safe, than Robinson's cheaper piston version.

Defective Carburetor Results in Jury Verdict Against Avco Lycoming

A Philadelphia jury has determined that a defective carburetor caused the 1999 crash of single-engine aircraft that killed four and injured one. The aircraft, a Piper Cherokee Six, was manufactured in 1968. The jury’s verdict included $25 million for compensatory damages and $64Piper Cherokee Six - PA32 million as punitive damages against the engine manufacturer Avco Lycoming, a division of Textron.

Since the Aircraft was Older than 18 Years, Why Didn’t the General Aviation Revitalization Act Protect Lycoming from Liability?

There are a number of exceptions to the General Aviation Revitalization Act (known as GARA). In particular, GARA doesn’t apply when the manufacturer, in obtaining FAA certification of its part, conceals from the FAA information about defects in the part's design. The jury in this case determined that Lycoming did just that. Thus, GARA was no defense.

The NTSB Determined the Cause of the Crash was Pilot Error. Its Report Didn’t Say Anything About a Defective Carburetor. Why Wasn’t the Jury Bound by the NTSB’s Findings?

The NTSB’s accident reports almost always favor the manufacturers. That’s because the NTSB relies on the manufacturer for help in determining the cause of the crash it is investigating. The NTSB calls this method of investigation the “party system.” 

Of course, asking the manufacturer for help in figuring out if thPrecision Carburetorere was a defect in its engine is much like asking the fox for help in determining what happened to the chickens. There’s a built-in conflict of interest. The NTSB is aware of the conflict, but continues using the party system anyway.

Here, after consulting with Lycoming’s experts, the NTSB decided not even to examine the carburetor. Since the NTSB never tore down this critical component, it’s no surprise that the NTSB did not discover any problems with it.

Fortunately for the victims’ families, the NTSB’s conclusions are by regulation inadmissible in court.

Why Did the Jury Award Punitive Damages?

A jury cannot award punitive damages simply because the defendant was negligent, or just

because the design of a defendant’s product was proven defective. Rather, the defendant’s conduct must evidence a “conscious disregard of the safety of others.”

Here, the jury determined that Lycoming willfully concealed from the FAA information concerning possible defects in its carburetor – even though it knew that any such defects could cause unnecessary injury or death. That fact alone demonstrates that Lycoming acted in conscious disregard of the safety of others, and justifies a punitive damages award.

The punitive damages in this case amounted to about 10 percent of Avco Lycoming’s net worth. The jury determined that that sum was sufficient to dissuade Lycoming from hiding from the FAA its knowledge of defective parts in the future. In other words, it was an amount calculated to take the profit out of Lycoming’s wrongdoing.

Why Didn't Lycoming Just Settle Instead of Going to Trial?

Good question.  Lycoming's best settlement offer was $75,000 to be split among all the plaintiffs.  In other words, Lycoming offered plaintiffs virtually nothing.  It was Lycoming, not the plaintiffs, who forced the matter to trial.

What other Factors were at Play?

According to the report of the plaintiffs’ attorney, the court had ordered Lycoming to turn over to plaintiffs all relevant documents about the carburetor before trial. Lycoming, however, intentionally withheld certain documents without telling plaintiffs that they existed. Lycoming’s litigation strategy – if it can be called that – backfired when the plaintiff’s attorney obtained the documents from another source and then proved during trial that Lycoming was hiding evidence.

Is this Verdict Unprecedented?

The plaintiffs’ attorneys did a wonderful job overcoming many obstacles that the manufacturer placed in their path over the last 9 years or so.  And punitive damages awards are rare indeed.

But while the verdict in this case is out of the ordinary, the story underlying the verdict is not:

  • Aviation manufacturers have a history of concealing defects in the design of their products.
  • After an accident, manufacturers frequently convince the NTSB to look no further than the pilot, or perhaps a mechanic, as the cause of the crash. Just as Lycoming did here, they often convince the NTSB that there is no need to dig into their engine before completing its report.
  • When the defect is discovered by experts hired by the victims' families, the manufacturers adopt a “defend at all costs” mentality.  Just as did Lycoming, manufacturers generally refuse to accept any responsibility for the harm they have caused unless and until a jury requires them to. 

Another example involving a more recent crash and a Teledyne Continental Motors engine is discussed here and here.

Related Material: The plaintiff attorney’s account of the verdict. 

Running Past TBO: Smart Economics or Owner Negligence?

Aircraft engine manufacturers recommend that owners overhaul their engines when they accumulate a certain amount of operating time, usually between 1200 and 2400 hours depending on the engine's make and model. For example, Teledyne Continental Motors suggests that owners overhaul its IO-550 model engine at 2000 hours. Textron LycLycoming Engine - photo by wirelizardoming suggests that owners overhaul its O-235 engine, like the one pictured, at 2400 hours.

Overhauls are expensive.  Some can cost $40,000 or more.  An increasing number of owners opt to run their engines 200, 400 or more hours past the manufacturer's recommended "time between overhauls," or TBO.  Once past TBO, they may take extra precautions by, for example, regularly sending out engine oil samples for spectrographic analysis, checking the engine’s compression, and looking inside certain parts of the engine with a boroscope to insure that  things look good. They feel the manufacturer's TBO recommendations are somewhat arbitrary. By running their engines past TBO they are squeezing more life out of them, and that just makes good economic sense.

The FAA does not require private owners to comply with the manufacturer’s stated TBO interval. The manufacturer's TBO is therefore advisory only.  As long as a properly certified mechanic has

within the previous twelve months certified that the engine is airworthy, then the owner is, from a regulatory standpoint, free to operate the engine as many hours as he wishes.

But if an owner does operate past TBO, and the engine fails, and a passenger is hurt as a result, could the owner be held accountable despite the fact he was in compliance with all FAA regulations?

You bet.

An owner can be held accountable for an accident after TBO if a judge or jury decides that:

1.  in not complying with the manufacturer's overhaul recommendations, the owner was negligent (not "reasonably careful" under the circumstances) and

2.  the negligence was a cause of the accident. 

The FAA regulations are minimum standards only.  Many would argue that more can and should be expected of a reasonably careful owner or operator.  If a judge or jury agrees, then the operator would be held responsible for the harm resulting from running the engine past TBO, even though the regulations allowed him to.

How would the aviation attorney representing the injured passenger establish the owner's liability?  Through expert testimony.  Let's say that at 100 hours past TBO an exhaust valve failed, the engine lost power, and an accident resulted.  It wouldn't be difficult to establish a causal link between the owner's decision to run the engine past TBO and the engine failure. 

Q: Mr. Metallurgist, did you find any defect in the exhaust valve?

A: No, it was manufactured properly and was a fine example of an exhaust valve in all respects.

Q: Then why did it fail?

A: It failed in fatigue. It took all the vibration, bending, and heat that it could and then it finally quit.

Q: Would it have broken if the owner had not continued to run the engine past the manufacturer's 2000 hour overhaul interval?

A: No, sir, it would not have broken had the owner followed the manufacturer's recommendation.

Q: How do you know that?

A: Well, for one thing, it completed the manufacturer's service interval without breaking. It broke only when the owner asked more of it than the manufacturer recommended. Certainly, had the engine been overhauled at 2000 hours and a new valve installed, one would not expect it to have failed in fatigue 100 hours later. Rather, one would have expected the valve to continue in service well beyond that.

The injured passenger's attorney would next call to the stand the owner of an FBO (aircraft rental agency).  The FBO owner would testify that he never runs engines beyond TBO because he doesn't assume that he is smarter than the manufacturer.  He would testify that some things, like whether internal parts are worn beyond safe limits, cannot be determined without tearing down the engine. The witness might then suggest that the costs saved by running an engine beyond TBO are marginal and just aren't worth the risk to human life. 

With the testimony of those two witnesses, a judge or jury could well decide that the owner was negligent in operating his engine past TBO and that the negligence caused the passenger's injuries.

Some proponents of running an aircraft engine beyond TBO downplay the risks.  They argue that the manufacturer's TBO is a "made up" number, and few engine failures have actually been attributed to the owner's decision to run past it.  One prominent aviation maintenance expert even suggests that there have been no cases where running past TBO resulted in an owner being held responsible for a passenger's resulting injuries.

Not so.  

There may be good economic reasons to run an engine past TBO.  But an owner who does so should expect to be held responsible if an accident results. 

A Mechanic's Liability for Failure to Comply with a Manufacturer's Maintenance Instructions

The General Rule

Mechanics are required by regulation to follow the instructions set forth in the manufacturer's maintenance manuals when working on an aircraft.  The mechanic is not allowed to deviate from the instructions covering the work he undertakes.  If he does deviate, and someone is injured as a result, the mechanic is liable.

Service Bulletins

Sometimes, a manufacturer learns of a problem with the way its product is performing in the field.

The manufacturer may then issue a “service bulletin” to warn the industry of the problem and how to correct it.  For example, when it learned that its exhaust valves were failing at an unacceptably high rate, one engine manufacturer  issued a service bulletin requiring that those valves be inspected regularly (pdf) and, if necessary, repaired or replaced.  GA MechanicThe service bulletin warns that failure to perform the inspection can result in engine failure.  Because the risk is so great, the manufacturer labeled this particular service bulletin "mandatory."

If a mechanic works on an aircraft but returns it to service without performing the "mandatory" inspection, is the mechanic responsible to those injured if the engine quits shortly thereafter due to valve failure?

You might think so.   After all, of all the manufacturer's instructions, those in the service bulletins might be the most important.   However, the regulations allow mechanics to ignore service bulletins entirely, even “mandatory” ones, and still pronounce the aircraft to be "airworthy."  That is, at least when working on aircraft operated under Part 91 of the FAA regulations—the section under which most general aviation aircraft are operated.   

The Industry Practice

When an aircraft is brought into the shop for service, many mechanics provide the owner with a written list of the service bulletins that apply to the owner's aircraft.  Unless the maintenance manuals expressly require the mechanic to comply with all service bulletins, the mechanics leave that decision to the owner. After explaining to the owner the work entailed, its cost, and its importance to flight safety, these mechanics require the owner to direct them, in writing, either to comply with the various service bulletins or to ignore them.

The mechanics keep the owner's written instructions on file.  In the event of an accident, the mechanic will argue that, although he was the one who pronounced the aircraft "airworthy," it was the owner who decided not to follow the manufacturer's recommendations.  The mechanic will argue that therefore the owner, not the mechanic, is the one responsible for the resulting injuries or death.