Thomas Frank

USA TODAY

The first flight of 8-year-old Caryn Stewart's life was supposed to be a quick sightseeing tour over eastern Iowa in her uncle's four-seat Piper Cherokee.

Nervous and excited, she sat quietly behind her mother and next to her sister as Andy Bryan, a cousin, drove the single-engine plane down Runway 17 at George L. Scott Municipal Airport.

The airplane elevated briefly and plunged into a field where it exploded into flames. Caryn suffered severe burns that scarred her torso, back, arms, legs and face. Her mother, cousin and 11-year-old sister were killed, part of a massive and growing death toll from small-aircraft crashes.

Manufacturing companies and federal investigators would say Bryan lost control of the Piper on that Easter Sunday in 2005. But company documents and government records pointed to a different cause: a faulty carburetor that the manufacturer later urged airplane owners to remove because it was causing engine failures.

Nearly 45,000 people have been killed over the past five decades in private planes and helicopters — almost nine times the number that have died in airline crashes — and federal investigators have cited pilots as causing or contributing to 86% of private crashes. But a USA TODAY investigation shows repeated instances in which crashes, deaths and injuries were caused by defective parts and dangerous designs, casting doubt on the government's official rulings and revealing the inner workings of an industry hit so hard by legal claims that it sought and won liability protection from Congress.

Wide-ranging defects have persisted for years as manufacturers covered up problems, lied to federal regulators and failed to remedy known malfunctions, USA TODAY found. Some defective parts remained in use for decades — and some are still in use — because manufacturers refused to acknowledge or recall the suspect parts or issued a limited recall that left dangerous components in hundreds of aircraft.

The manufacturers involved paid hundreds of millions of dollars in settlements that received little or no public attention until now and that need not be disclosed to federal regulators. In addition, civil-court judges and juries have found major manufacturers such as Cessna Aircraft, Robinson Helicopter, Mitsubishi Aircraft, Bell Helicopter and Lycoming Engines liable for deadly crashes, ordering them to pay hundreds of millions of dollars in compensatory and punitive damages.

The verdicts contradict findings of the National Transportation Safety Board, which conducts limited investigations into most crashes of private aircraft and asks manufacturers to look for defects in their parts, even if the manufacturers are being sued over a crash.

Judges and juries have spent weeks hearing cases that took years to prepare and unearthed evidence that NTSB investigations never discovered.

A Florida judge, finding that Cessna had known for "many years" of a potentially lethal defect in thousands of planes but hadn't fixed it, wrote in 2001 that the company could be guilty of "a reckless disregard for human life equivalent to manslaughter."

A USA TODAY review of tens of thousands of pages of internal company records, lawsuits and government documents found defects implicated in a series of fatal crashes of small planes and helicopters. The deadly defects include:

• Helicopter fuel tanks that easily rupture and ignite, causing scores of people to be burned alive after low-impact crashes that were otherwise survivable;

• Pilot seats that suddenly slide backward, making airplanes nose-dive when pilots lose grip of the controls.

• Ice-protection systems that fail to keep airplane wings clean during flight and fail to warn pilots of dangerous ice buildup that causes crashes.

• Helicopter blades that flap wildly in flight and separate from the mast or cut through the helicopter tail.

• Airplane exhaust systems that leak exhaust gas, causing engine fires.

• Carburetors such as the one in the Iowa crash that flood or starve engines and had been causing midair engine failures since at least 1963 when the federal government notified the manufacturer of "a serious problem" with its carburetor that had caused a recent fatal crash.

Manufacturers say crashes are caused by pilot errors, aircraft neglect or owners' failure to follow manufacturer bulletins urging part replacements.

After the Iowa crash, engine maker Lycoming and carburetor maker Precision Airmotive blamed the pilot in the face of a lawsuit by Caryn Stewart's father and uncle. In April 2013, after a judge rejected both companies' requests to throw out the case, the companies paid the two men a $19 million settlement, court records show.

Ruling against Lycoming and Precision, Philadelphia Judge Matthew Carrafiello found evidence both might be culpable. Precision had received more than 100 warranty claims concerning carburetor defects, the judge said, and Lycoming continued to use the carburetors even though it "knew of ongoing problems" with the carburetors "and of numerous plane crashes resulting from such problems."

None of that information was included in the NTSB investigation, which was aided by Lycoming and Precision and blamed Andy Bryan, the pilot, for "failure to abort the takeoff" and "failure to maintain adequate airspeed during takeoff."

"It was just like a conviction when they said that," said Greg Bryan, Andy's father and the airplane owner. "That's your son's legacy — our family's legacy — that we did something to cause this terrible accident."

The danger of private airplanes and helicopters — known as "general aviation" — far exceeds that of airline flight. In 2013 alone, there were 1,199 general-aviation crashes — more than three per day on average — killing 347 people, injuring 571 and destroying 121 aircraft.

A domestic passenger airline hasn't crashed since Feb. 12, 2009, when 50 died on Colgan Air Flight 3407 near Buffalo.

While the airline crash rate has plummeted to near zero, the general-aviation rate is unchanged from 15 years ago — and roughly 40 times higher than for airlines.

"When you look at aviation, the place where people are getting killed is general aviation. Year after year, we are killing hundreds of people in general aviation," said former NTSB chairwoman Deborah Hersman, who left in April to become president of the National Safety Council.

The crashes have killed tens of thousands of amateur pilots in single-engine airplanes, police and medical workers in emergency helicopters, farmers in agricultural sprayers and business executives in corporate jets.

No other country experiences anything similar. The U.S. has more than twice as many general-aviation aircraft as every other nation combined and is home to leading manufacturers and a powerful lobby, which persuaded Congress in 1994 to bar injury and death claims involving aircraft and parts that are more than 18 years old. That is significant protection: Roughly three-quarters of the nation's 220,000 general-aviation aircraft are more than 18 years old.

The law was enacted after multimillion-dollar settlements and verdicts — including a $29 million verdict against Cessna for a crash that killed three and $22 million against Mitsubishi for a crash that killed five — that escalated insurance costs and forced some manufacturers into bankruptcy.

Judges have dismissed many lawsuits under the 1994 law. But major verdicts continue because the law allows claims concerning newer parts and against manufacturers that allegedly covered up defects.

USA TODAY found 80 lawsuits involving 215 general-aviation deaths since 1994 that resulted in a manufacturer paying a settlement or damages of at least $1 million. The verdicts include $70 million against General Electric for a helicopter crash that killed seven firefighters and two crewmembers; $48 million against parts maker Doncasters for a crash that killed five skydivers and a pilot; and $26 million against Lycoming for a crash that killed three, including a 10-year-old girl and her mother.

As damages have mounted, manufacturers have stonewalled plaintiffs' attorneys and federal officials in recent major cases. Judges have sanctioned and scolded companies for withholding information in at least a dozen lawsuits, USA TODAY found.

The $26 million verdict against Lycoming came in a carburetor-defect lawsuit after a judge found that the company repeatedly refused to turn over documents to plaintiffs. In February 2013, Washington state Judge Monica Benton found that Lycoming "has been in continuing contempt of court" since 2011 and decided to hold it liable for the 2008 crash. A jury later awarded the survivors $26 million, which includes $6 million in punitive damages. The award is being appealed.

In a lawsuit blaming a crash on a failure of a computerized cockpit display, federal magistrate Judge Janice Stewart of Oregon rebuked display manufacturer Avidyne Corp. in a 2010 hearing for its "failure to produce" documents, calling it, "at best, grossly negligent."

The government was stonewalled, too. Two years earlier, when the NTSB investigated failures of the cockpit displays, Avidyne refused to give the board information about displays that had malfunctioned. Avidyne called the request "overly broad, not relevant and onerous," according to NTSB records.

Sikorsky Aircraft withheld from the NTSB and plaintiffs an analysis it did in 2009 after seven oil workers and a pilot were killed when one of its helicopters crashed en route to a Gulf of Mexico oil rig. Sikorsky did not release the analysis, which showed problems with its helicopter model that crashed, until nearly 1½ years after it was written — three months after the NTSB cleared the company.

Federal magistrate Judge Karen Wells Roby wrote that "the only plausible reason" for Sikorsky's delay is because the analysis was "adverse to Sikorsky's interests." Roby ordered Sikorsky to pay $577,000 in legal penalties.

One of the most gruesome and long-standing problems has caused scores of people to be burned alive or asphyxiated in fires that erupt after helicopter crashes. Such deaths are notorious because they can occur after minor crashes, hard landings and rollovers that themselves don't kill or even injure helicopter occupants. The impact can rupture helicopter fuel tanks, sending fuel gushing out, where it ignites into a lethal inferno.

Using autopsy reports and crash records, USA TODAY identified 79 people killed and 28 injured since 1992 by helicopter fires following low-impact crashes. In 36 non-fatal crashes, fire destroyed or substantially damaged helicopters after minor incidents such as rollovers, crash reports show.

Although crash-resistant fuel tanks have been available since the early 1970s, when the Army installed them and dramatically reduced soldiers' deaths, many manufacturers have not bothered, one safety expert said, because of the added cost, which the FAA has estimated at several thousand dollars per tank.

"If it's cheaper to let you die than to fix it, you're going to die," said Harry Robertson, who invented the crash-resistant "Robbie tanks" for the Army and is in the National Aviation Hall of Fame.

Robinson Helicopter Co. of Torrance, Calif., came up with a solution in 2006 that cost the company nothing. It issued Safety Notice SN-40, advising pilots and passengers to wear fire-retardant Nomex fiber suits to protect themselves in a fire.

Company President Kurt Robinson said in an interview that the notice was issued because of a crash three months earlier in Fredericksburg, Texas. A Robinson R-44 clipped a power line, fell to the ground and erupted in flames. Alec Beck died of burns and smoke inhalation, with "no evidence of blunt force trauma," and Gayla Leonard died of smoke inhalation and did not break a bone, according to their autopsy reports. Pilot Craig Nemec lived for 14 months with burns over half his body, had both arms amputated, lost his vision and underwent roughly 20 surgeries, his wife, Ellen Nemec, said. In June 2007, he died.

Robinson's Nomex-suit advisory appears to have had little effect. There were 320 Robinson helicopter crashes in the U.S. after it was issued; not a single occupant was wearing a Nomex suit, NTSB reports show. "It was ignored by a large group of people," Robinson said.

Nemec called the advisory "absurd" and began pushing Robinson to make safer fuel tanks.

Safety experts and officials have recently warned about the fuel tank in the R-44, one of the world's best-selling helicopters. Its two aluminum fuel tanks are packed on either side of a 3-inch-thick steel mast that controls the rotor, said Bill Waldock, a crash expert at Embry-Riddle Aeronautical University in Arizona, who has been an expert witness in lawsuits against Robinson. If the helicopter rolls onto its side, the mast can rupture a tank, sending jets of fuel spurting forward into the cockpit to be ignited by a spark, he said.

"I've looked at about 14 of these, and you see essentially the same pattern in each one," Waldock said.

Problems became apparent less than a year after the R-44 went on the market when a 1993 crash killed three people near Los Angeles. Pilot Benjamin Venti Jr. and passenger Nicholas Lovoy both died from "inhalation of products of combustion and thermal burns," the Los Angeles County Coroner found. A total of 14 people have been killed and seven injured in the U.S. from post-crash fires of the R-44 and the Robinson R-22, an earlier model, crash records and autopsy reports show.

But it wasn't until roughly 2006 that Robinson began developing fuel-tank bladders to be installed in its R-44s and R-22s. The company started selling the bladders in late 2009, for $6,800, and installing them on its new helicopters. Kurt Robinson said the bladders "significantly enhance safety" and defended the helicopters' safety record, noting that they complied with FAA regulations. Robinson became company president in 2010 and said he can't speak to crashes before then.

In March 2013, the Australian Civil Aviation Authority ordered all R-44 owners to install fuel bladders within a month or be barred from flight. Three "low-energy" R-44 crashes in Australia since 2011 had caused fires and killed eight people, the authority said.

The NTSB in January asked the FAA to issue a similar order, citing lethal R-44 fires in the U.S. The FAA said in reply that the R-44 "does not appear significantly different" from similar helicopters in terms of fire risk and is studying the matter.

After her husband's death, Ellen Nemec learned about earlier R-44 crashes that sparked deadly fires and grew angry. "Had it not been for this really insufficient fuel tank that Robinson knew about," she said, "this would have been just a bad landing."

Some problems have persisted for decades as manufacturers have minimized dangers and struggled to develop solutions.

As early as the 1960s, pilots and NTSB investigators were reporting that Cessna pilot seats were sliding backward on the rails designed to grip them. Airplanes crashed when pins that held seats in rail holes popped out, letting seats slide so far back that pilots could not reach the controls.

"Pilot's seat slid to full rear position on bounced landing," the NTSB wrote of a Cessna 172 hard landing on Aug. 18, 1966, in New Jersey.

Similar NTSB reports followed: "Pilot's seat slid back. Unable to reach controls" (April 11, 1969, Alaska). "Pilot's seat unlatched and moved rearward during takeoff roll" (Aug. 30, 1969, Milwaukee). "Pilot seat not locked before takeoff, seat slid back" (Aug. 8, 1971, Pennsylvania).

After urging owners of its military models in 1975 to replace worn parts, Cessna waited until 1983 to notify civilian owners — 17 years after the NTSB first noted a problem.

Cessna's civilian notice was a low-priority "service information letter," which said nothing about the danger of a seat sliding backwards. Its title: "Seat rail inspection guidelines."

But when the FAA proposed in 1987 issuing a mandate for Cessna owners to inspect seat rails and replace worn parts, the company grew worried.

Mandatory seat-rail inspection "would result in a significant number of seat rails that required replacement," Cessna said in an Aug. 7, 1987, letter to the FAA.

The problem, Cessna added, is that "with present production capabilities, we would be unable to supply massive quantities of rails." That could ground thousands of airplanes if their seat rails were found to be worn and replacements weren't available.

The FAA tried to accommodate, according to a Sept. 4, 1987, agency memo, and encouraged Cessna to develop "an inexpensive interim modification for defective seat rails that would prevent aircraft groundings."

Cessna developed and began selling the inexpensive modification, but it was difficult to install and involved "awkward operation," Cessna noted in an internal memo. Cessna owners, who could choose whether or not to buy the modification, were so reluctant that the company estimated replacing every seat rail would take 600 years.

On Aug. 14, 1989, James Cassoutt, his wife, Cindy Cassoutt, and a friend, Judy Kealey, suffered extensive fractures, burns and organ injuries when Cassoutt crashed his Cessna A-185E, which did not have the new part. After a Florida judge found that Cessna's responses to the seat problems "were neither timely nor adequate," a Florida jury awarded the three $480 million, including $400 million in punitive damages. The 2001 case settled for $41 million, court records show.

Cessna insisted that the crashes were caused by pilots who didn't maintain the seats or assure they were secured before takeoff. The company said in a statement to USA TODAY that its aircraft are safe "when they are used and maintained as required by published guidance."

Cessna developed a safety device in 2007 to stop a pilot's seat from sliding if the rail pins came loose, but since then there have been at least five Cessna crashes involving seat sliding, federal records show. The crashes killed one, injured three and substantially damaged all five airplanes. It's unclear how many pilots installed the devices because the FAA never mandated their installation, despite a plea by Cessna.

In 2011, the FAA required Cessna owners to conduct more thorough seat inspections than it ordered in 1987 because "inadvertent seat movement continues to be a safety issue."

But a federal judge warned that inspections and warnings do not compensate for a defective design. "Even if the pilot takes all of the precautions urged by Cessna," Judge David Herndon of Illinois wrote in 2005, "the pilot may be left with a false sense of security because he or she believes the seat is properly locked, when it is not."

Other manufacturers have moved quickly to replace defective parts but with recalls that are limited and leave potentially defective parts in many aircraft.

Lycoming Engines faced a choice when it discovered in 1998 that two helicopters lost engine power in flight because a bolt fractured in each of their Lycoming engines.

No one was hurt. But Lycoming had to decide what to do about thousands of similar bolts in its stockroom and inside various helicopter and airplane models.

The company recalled about 160 bolts from helicopters and removed 4,250 bolts from its stockroom "as a purely precautionary measure," according to a statement Lycoming gave the NTSB.

Lycoming issued no recall or warning for the roughly 1,100 similar bolts still in airplanes. Bolt fractures were "limited to helicopter applications," the company believed. The FAA agreed.

By early 2001, bolt fractures had caused engine failure in three Lycoming-powered planes, including two Royal Jordanian Falcons, a rare model of aerobatic aircraft, and the popular Piper Saratoga II. There were no injuries.

Facing another decision, Lycoming again took limited action. It replaced bolts in all Falcons, which was easy and cheap because there were only five of the airplanes. The hundreds of Piper Saratoga II owners got no recall or warning.

Bolt fractures "were not thought to extend beyond helicopter and aerobatic applications," Lycoming told the NTSB. The FAA agreed again.

On June 7, 2002, Mississippi dentist Mark Williams was flying his Lycoming-powered Piper Saratoga II near home when the engine suddenly stopped. Williams crashed and suffered severe fractures and internal bleeding, for which Lycoming later paid him $2.85 million, according to court papers. A Lycoming metallurgist wrote that the "primary cause of engine failure" was a fractured engine bolt.

Lycoming took no immediate action. The company declined to comment on the bolt fractures.

On Sept. 8, 2002, a Piper Saratoga II flying out of New Jersey lost engine power and crashed. Two boys, ages 8 and 5, were severely burned but survived. Their parents, Michael and Sandy Kirkley, were killed. The FAA quickly pinpointed the cause as bolt fracture, prompting Lycoming to recall bolts on roughly 1,000 engines in dozens of types of airplanes, including the Piper Saratoga II.

Williams received the recall notice around his 40th birthday and remembers thinking, "I would have loved to be one of the people in the recall opposed to the one who is the reason why there is a recall."

The Kirkley boys sued Lycoming, saying the company had known about the bolt problems since 1998 "but failed to take any precautionary action." The lawsuit settled for undisclosed terms.

The defects blamed for the crash that killed Caryn Stewart's mother and sister also generated allegations that a manufacturer tried to avoid a costly recall. The problems involve a small component called a "float," which controls the fuel level in a carburetor the same way a toilet-bowl float controls water in a bowl cabinet. The floats were causing engines to fail by saturating the carburetor with fuel, although one manufacturer was caught lying.

In the 1970s, carburetor maker Borg-Warner found that the floats' composition was causing the problems, company memos show. Faced with a potentially costly recall of a defective part, Borg-Warner told the FAA something different: Pilots caused the problems by using automotive gas instead of aviation fuel.

"This statement to the FAA is in fact false," an Alaska judge wrote in 1990, awarding $6.7 million to the widow of a man killed in a 1986 crash in Alaska. Borg-Warner likely would have paid for a $23 million recall "if a manufacturing defect was acknowledged," Superior Court Judge Jay Hodges wrote. The company's "failure to disclose" the actual cause "is outrageous conduct."

Hodges' verdict included $5 million in punitive damages — but it didn't stop the problems.

After Precision Airmotive bought the carburetor line in the 1990s, it began making plastic floats to replace metal floats that "malfunction when a leak develops," according to a patent for the plastic float. Yet Precision said nothing about malfunctions when it announced in 1998 that plastic floats were available, saying only that they would "improve service life and resistance to damage."

In 2010, a jury awarded $89 million, including $64 million in punitive damages, to survivors of a 1999 crash of a Piper Cherokee equipped with a metal float. Four people were killed and a teenage boy was seriously injured. The case settled for $20 million, according to court records.

The judge in the case involving Caryn Stewart also was critical, noting that Precision "did not mention that the new float resolved problems" and "did not notify the FAA that it had identified and resolved a defect."

The crash itself was horrifying. Caryn Stewart recalled her cousin yelling at everyone to get out, and her sister Sarah screaming a "blood-curdling scream." Caryn suffered burns over 75% of her body.

Brian Stewart lives a mile from the airport where the plane crashed and still struggles with his loss. "Some days it's hard, some days you just go by it," Stewart said. "It's never out of your mind."