This article is presented by SumpThis with permission courtesy of The Wall Street Journal.

WSJ.com

April 30, 2001
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Air and Water: FAA Tests Put Cloud Over Cessna's Revival Of Single-Engine Planes
Accidents Blamed on Flaws In Fuel System Ignite Debate on Popular Plane --- Losing Power at 3,000 Feet

By Jerry Guidera
Staff Reporter of The Wall Street Journal

After Brad Schroeder crashed while piloting a single-engine Cessna Skyhawk near Chicago in 1991, investigators from the National Transportation Safety Board added insult to injury.

They faulted Mr. Schroeder, who nearly died in the crash, saying he had failed to perform the proper preflight safety routine for draining water from the fuel tank. The investigators had concluded that water from the tank had entered the Skyhawk's engine, shutting it off at 1,100 feet. But Mr. Schroeder insisted that he had followed the preflight instructions to the letter, including the draining regime. The NTSB finding "didn't make any sense to me," he says.

Now, the Federal Aviation Administration has taken action that may shed further light on this and similar crashes over the years. Prompted by pilots and recent incidents that have raised suspicion, the FAA is conducting tests to determine if the fuel system in several popular Skyhawk models is defective and prone to delivering water to the engine.

For Cessna Aircraft Co., the FAA's tests pose a threat to what has been the successful rejuvenation of its single-engine business, restarted in 1996 after a 13-year shutdown. In 1983, Cessna shuttered its single-engine operation, blaming an onslaught of product-liability lawsuits, some of which alleged defective fuel tanks. In 1994, after years of intense lobbying by Cessna and others, President Clinton signed into law the General Aviation Revitalization Act, which gave single-engine aircraft manufacturers like Cessna broad immunity from liability lawsuits. Cessna resumed production at a new plant in Independence, Kan.

A unit of Textron Inc., Cessna insists that its planes are safe and says it expects the tests will prove that. An FAA spokeswoman says preliminary results from the tests, which are continuing, indicate that the aircraft pose no immediate danger to pilots who perform a proper preflight check.

By far the largest American manufacturer of single-engine propeller airplanes, Cessna says as many as 20,000 aircraft -- which range in price from about $144,000 to $300,000 -- incorporate the fuel-tank structure under investigation. More than 100,000 single-engine Cessna planes, flown primarily for recreational purposes and by small businesses, are in use in the U.S. Cessna, which makes most of its money from selling expensive jets to business customers, contributed more than 20% to Textron's $13 billion in revenue last year, up from barely 10% eight years ago.

The NTSB has put its database for all U.S. air accidents since 1983 online. A review of those reports for the five years since Cessna resumed single-engine production turns up a total of 2,149 accidents involving single-engine Cessna planes. Of those, 25 were at least partly caused by watery fuel, with two resulting in deaths, federal investigators said.

The pilot in each case had failed to perform proper preflight checks of the tanks, the investigators said. They also found water in the fuel system in 29 other Cessna aircraft involved in crashes during the period, some of them fatal, in which the cases are still under review or were closed without determination of cause.

Cessna, based in Wichita, Kan., declined to comment on the NTSB records. But it said in a statement responding to questions that fuel contamination is "an aviationwide issue," and that the company has worked diligently to inform pilots of how to find and deal with water in the fuel. Cessna single-engine "tanks are designed and continuously improved to make it as easy as possible, if proper preflight procedures are followed, to detect and remove all hazardous amounts of water," the statement said.

"Our kids fly in these, our wives," says Steve Copeland, a Cessna engineer who is the company's liaison to the FAA investigation. "We're not going to get into these airplanes unless they're safe."

But some aviators, relatives of crash victims and others say that the planes are flawed and the review is long overdue. They also say that the tests, which focus only on a newer type of fuel tank, should be broadened to include an older tank design. Large numbers of both tanks are in use, and together the two designs account for most of the single-engine Cessnas in the American market.

"Cessna has tried to bury its head in the sand over this issue," says Richard French, a Cleveland attorney who has handled liability cases for and against the aircraft manufacturer. In 1987, Mr. French reached a $775,000 settlement with the company after alleging in a lawsuit that a Cessna that crashed near Elyria, Ohio, went down because of water in the engine caused by a defective fuel tank. The 1986 crash, which involved an aircraft with one of the older-design tanks, killed the pilot, Scott Marx, and injured three family members. Cessna declined to comment on the case.

Keeping water out of the fuel system is a problem that has faced aviation since its inception. Water can get into an airplane's tank accidentally in a number of ways, including condensation released from the fuel under rapid outside temperature changes, seepage from a loose overhead gas cap or cracks in a wing, or by refueling with a source already contaminated by water. When water reaches the engine, it can snuff out combustion, causing a shutdown.

Cessna pilots are told in training and operating manuals to check the fuel system for water during preflight preparations. On new models of the Cessna Skyhawk, the most popular single-engine aircraft in the U.S., this involves opening a total of 13 sumps, or drains, at various low points in the fuel system. The idea is that water, which is heavier than airplane fuel, will sink to the low spots. New Skyhawks carry their fuel enclosed in hollows in each wing called integral tanks, or wet wings. Each of the two 28-gallon tanks carries five sumps at various locations along the belly of the wing. The three remaining drains are farther down the fuel system.

Cessna began installing wet wings in 1967, gradually replacing a design that stored the fuel in a rubber bladder inside the wings. Pilots liked the new design because it boosted fuel-carrying capacity and allowed longer trips. Cessna says it has had fewer reports of accidents with the wet-wing planes than with the bladder-equipped models. "It's been a great system for us," says Stanley J. O'Brien, head of propulsion for Cessna's single-engine operations.

Both designs have been the subject of Cessna and FAA safety actions over the years. In 1982, Cessna began including in its flight manual for single-engine Cessnas new preflight instructions about drainage, which were also included in a service bulletin to owners of older models. If water was detected after an initial opening of the drains, pilots were instructed to "gently rock" the wings and to lower the tail "to move any additional contaminants" to the drains. The routine, which came to be known as the "rock and roll" procedure, remains a part of recommended preflight preparation.

In 1983, the FAA issued one of its rare Airworthiness Directives, ordering owners of most bladder-equipped, single-engine Cessnas to check the bladders for "any wrinkles which retain fluid after draining" and to replace them as needed. The reason for the order, the FAA said, was "to prevent power loss or engine stoppage due to water contamination of fuel system." Cessna issued a similar warning that year.

In 1992, Cessna issued a service bulletin to owners of aircraft with wet wings warning them about water-related problems and offering owners kits, sold at cost, for installing four additional drains under each tank "to assist in the detection and removal of water." Cessna hoped the drains would make the preflight check "idiot-proof," says Mr. Copeland. Cessna also issued a reminder bulletin offering the new drains in 1996.

Over the years, Cessna says it has faced between 40 and 50 suits alleging that water from the bladder cells contributed to crashes. All those suits have been resolved, and the company says it hasn't faced a new suit in six years.

Eugene Odou, a retired doctor in Montebello, Calif., and a former medical examiner for the FAA, says his daughter Carol was killed in a 1983 water-fuel accident involving the family's Cessna 182P. This single-engine plane is a bit bigger than the Skyhawk and equipped with bladder tanks. Her husband, William Tatnall, who was the pilot, says he found water during the preflight check and then performed the rock-and-roll procedure before the fateful flight. He sued Cessna, contending that flaws in the bladder made it impossible to drain water that had seeped into one of the wing's fuel tanks.

The two sides reached an out-of-court settlement, say Messrs. Odou and Tatnall, who declined to disclose terms. Later that year, the FAA issued the bladder Airworthiness Directive. Cessna declined to comment on the crash or the lawsuit.

The recent regulatory attention was sparked in August 1998, when the engine of a Cessna piloted by Robert E. Scovill Jr. stopped in midflight, forcing an emergency landing in a farmer's field near Mr. Scovill's home in Smyrna, Tenn. He said it was the third time that he had had an in-flight engine hesitation with the plane, a wet-wing Skyhawk built in 1981.

For help, Mr. Scovill, a general contractor, called the FAA's office in Nashville, which dispatched inspector George Erdel. Together with Mr. Scovill's mechanic, they went through a standard preflight drainage check. Then Mr. Scovill tried to take off on a makeshift runway, but the engine sputtered to a halt. After Mr. Erdel checked the sumps for water again, he removed about a pint of water from the drains, he and Mr. Scovill say.

Mr. Scovill drained the fuel system completely, swabbed the tank with alcohol to remove any remaining water, refueled and flew the airplane home. Then he learned about the 1992 Cessna safety recommendation -- which he says he hadn't received earlier -- urging pilots to install additional fuel drains, and he did so. But afterward, on an April 5, 1999, flight, the airplane's engine stopped again, this time at 3,000 feet. Flying without power, he made another emergency landing, at Smyrna Airport.

Determined to see whether the plane was flawed, Mr. Scovill gathered a number of witnesses in his hangar in Murfreesboro, Tenn., for some tests. He poured a premeasured amount of water into his airplane's fuel tanks and performed the preflight procedures specified by Cessna. But not all of the water drained out.

Mr. Scovill then wrote to Craig Roberts, head of the FAA's Flight Standards District Office in Nashville, describing his repeated engine problems and the tests. The Cessna fuel system, Mr. Scovill said, is faulty, with a "consequent danger of crashing" that "is life-threatening."

Mr. Roberts and another FAA inspector, Paul Jones, performed the same water test on Mr. Scovill's airplane three months later and were unable to remove 13 ounces, even after shaking the wing. Mr. Roberts then wrote supervisors in Washington, calling for a "review of the water/contamination egress capability of the Cessna integral fuel tank which includes all similar designs" to the 172P -- the model number of Mr. Scovill's plane.

Although the fuel tank is designed so that water will sink to the lowest point on the wing, where the drains are located, critics of the wet-wing design say structural ribs along the inside of the wing can keep water from reaching the drains. Most critics say the main problem is that the slope of the wings isn't steep enough to allow the water to flow to the drains. The typical dihedral, or slope, on a Cessna single-engine airplane is between one and two degrees, compared with four or five degrees on other single-engine aircraft, experts say.

The other leading single-engine aircraft manufacturers, the Raytheon Aircraft Co. unit of defense giant Raytheon Corp., and Piper Aircraft Inc., don't advise their pilots to use the so-called rock-and-roll procedure.

The FAA in Washington sent details of the Tennessee water tests to Wichita, where the agency's single-engine certification office is based. Carlos Blacklock, then the head of the Wichita office, sent two inspectors to look at Mr. Scovill's plane.

They came back "with the conclusion that there is indeed water in the tank, and that it's hard to get it out," he says.

At about the same time, Robert Lee Cunningham, an FAA maintenance inspector in Orlando, Fla., was growing alarmed after a review he conducted at Embry-Riddle Aeronautical School in Daytona Beach, Fla. He turned up 83 pilot reports of problems in the schools' fleet of 58 Cessna Skyhawks, all wet-wing planes built after the 1996 manufacturing restart.

Mr. Cunningham wrote the school in January 2000, admonishing it about "repeat accounts of engine roughness and stoppage without conclusive corrective action," dating to the arrival of the first new Cessnas in the fall of 1997. He also says he advised Wichita the next month of his suspicion that water in the fuel tank was the source of the problem and urged the agency to order Cessna to correct the problem.

Embry-Riddle, the largest pilot school in the country and one of Cessna's biggest customers, asked the aircraft maker to fix the problem. Cessna eventually agreed to upgrade, without charge, all 58 of the planes, boosting their original 160-horsepower engines to 180-horsepower.

Embry-Riddle Chancellor Thomas J. Connolly says the engine hesitations have disappeared, and that tests performed at the school have shown water wasn't the issue. Neither Embry-Riddle nor Cessna say they can explain why the upgrade seemed to bring an end to the hesitations.

But Mr. Cunningham says that with the horsepower upgrades, Embry-Riddle instructors are now able to fill their fuel tanks to the top, leaving less room for condensation buildup or water entrapment. The school had been operating the weaker-engine Cessnas with the fuel tanks half full in order to save weight and accommodate extra observers on student training flights.

After reviewing accident and service-difficulty reports on Cessna single-engine airplanes filed with the NTSB, Mr. Blacklock and the FAA team wrote Cessna on March 13, 2000, identifying an "unsafe condition" on Mr. Scovill's airplane and probably many more. "We believe this condition may exist on all Cessna high-wing integral-wing fuel-tank-equipped airplanes," he wrote. Cessna says that description fits more than 20,000 of its aircraft in the field.

Mr. Blacklock ordered Cessna to propose specific design changes to remedy the apparent fuel-tank flaws. For Mr. Scovill's model, the 172P, Mr. Blacklock demanded proposals within 30 days. He also ordered the manufacturer to submit a list of all the other planes that used a similar tank design and corresponding serial numbers for each airplane in service, as well as proposed design changes for them within two months.

On April 10, Cessna's Mr. O'Brien responded, rejecting any reason for concern. He cited a prior FAA audit of the wet-wing fuel tanks in new Cessnas that found they "met regulatory requirements and performed as intended." Without proposing any design changes, Mr. O'Brien said Cessna would "initiate a significant investigative program" to determine if the 172P fuel-tank design is flawed and provide details of the program "in the near future."

FAA officials were growing frustrated, internal agency documents show. On May 30, the FAA's top regional inspection officers sent the manufacturer a letter requesting a voluntary halt to any shipments of single-engine aircraft from the new plant in Independence. Cessna officials say they were taken aback by the action. "It certainly got their attention," says John Hickey, the FAA's head of certification in Washington.

Cessna complied with the request. But that day, the company flew six senior officials in a company jet to Kansas City, Mo., to meet with the FAA's top regional regulators. At that tense meeting, Cessna provided agency officials with its own research into Cessna flying-safety records and persuaded the agency to limit the scope of its inquiry, according to people familiar with the matter. The FAA agreed to allow shipments to continue after just a one-day stoppage.

In a special hangar at Cessna's manufacturing facility in Wichita, FAA officials and company representatives are testing Cessna Skyhawk models 172R and 172S made after 1996. They are doing it much in the same way Mr. Scovill did -- introducing water and then seeing if the recommended draining procedure gets it all out. The 172Rs and 172Ss represent the bulk of Cessna's current single-engine production. FAA officials say the tests are being widened to other models to include the 172P, Mr. Scovill's older model.

Jeffrey Janusz, a former Cessna engineer who is heading the FAA's investigation, says there is a lot of tension between the agency and Cessna in Wichita. "Things have just gotten too heated up around here," he says. He says he is trying to reach a conclusive result that will resolve the matter. "I'm hoping to have a bulletproof case, whether it be good news or bad news," he says.

Write to Jerry Guidera at jerry.guidera@wsj.com

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