FAA Ignored Warnings on 757 Jet Turbulence : Safety: Action was urged before fatal crashes involving planes following too close. Agency has now made changes.

The Federal Aviation Administration’s top scientist warned--prior to two fatal airplane accidents--that wake turbulence from Boeing 757 jetliners would cause a “major crash” if the agency failed to take preventive measures, internal documents show.

The documents reveal for the first time that experts within the FAA had--before the tragedies in Billings, Mont., and Santa Ana--expressed serious concerns about the potential danger to planes operating behind 757s.

Eleven days before the Dec. 18, 1992, Billings crash killed eight people and a year before the Dec. 15, 1993, Santa Ana accident claimed five lives, chief scientist Robert E. Machol was granted a special meeting with the FAA’s hierarchy and predicted a “catastrophe” because of 757 wake turbulence.

Yet, it was not until after the Santa Ana accident that FAA Administrator David R. Hinson first drew nationwide attention to the problem, issuing a bulletin instructing air traffic controllers to routinely alert pilots to the threat posed by 757s. The plane’s unique, fuel-efficient design creates invisible “horizontal tornadoes” emanating from each wingtip that are more powerful and last longer than those created by other aircraft its size.

“It’s true,” Machol said in a recent interview. “I was the first guy within the agency who got up and said we’re likely to have a catastrophe, a real catastrophe, probably involving a DC-9 or a Fokker, and lose 70 to 100 people, if we don’t do something.

“I wanted to speak to the associate administrators because I was scared.”

The 226 pages of FAA letters and memoranda were obtained by The Times under the Freedom of Information Act after officials fought their release. An FAA spokesman said last week that the agency is investigating whether the records were withheld in violation of the federal disclosure law.

Sources have also provided The Times with documents indicating that agency officials were concerned about how Machol’s warnings might be viewed. On one of Machol’s memos, an official jotted a cautionary note that Machol should temper his words lest someone interpret the document to be a “smoking gun.”

The FAA has resisted efforts to increase separation distances between 757s and tailing airplanes because it could potentially decrease the number of flights at airports. That could cut into revenues of the fiscally hobbled airline industry. Even mid-sized passenger jets such as MD-80s, DC-9s and Boeing 737s, which can carry 100 passengers or more, can be “rolled” and knocked out of control when they encounter the 757s’ “wake vortex.” The hazard is greatest during landing and takeoff, when the smaller plane can inadvertently fall below the 757’s flight path and find itself entangled in a danger zone of swirling, hurricane-force winds.

Tony Broderick, the FAA’s associate administrator for regulation and certification, attended the Dec. 7, 1992, meeting and recalls Machol “expressing concern about wake vortices on a 757,” he said. But Machol failed to provide “specific data” to justify the agency’s immediate intervention, Broderick said.

Yet when Hinson recently announced new policies on 757s--including a requirement that pilots of smaller planes landing behind 757s maintain an extra mile of distance--no new data was presented, other than the two fatal accidents and three serious incidents over the past 18 months. Most of the new policies, which require air traffic controllers to be more cautious when dealing with planes trailing 757s, take effect this summer.

In retrospect, Broderick acknowledged, the FAA could have acted sooner.

“I think it’s certainly fair to say that these two tragic accidents caused us to place more emphasis on the wake vortex (research and development) project than we had in the past,” Broderick said. The combination of the accidents, Machol’s concerns and the existing research on 757s, he said, “convinced us that there were an awful lot of holes in our knowledge.”

Leo Garodz, a former FAA manager who expressed his concerns about 757 wake turbulence to the FAA in 1991 as a consultant, was surprised to learn that Machol had raised red flags on the agency’s wake turbulence policies as far back as 1989.

“They had their own guy saying the same thing and they still kept it quiet. That’s amazing,” said Garodz, a former fighter pilot who worked in the FAA’s wake turbulence program for two decades before retiring in 1986.

Machol, who retired from the FAA on April 30, said it was not unusual that his warnings went largely unheeded. “Well, it is, in general, true that the FAA does not put a significant amount of time and money into something until they have a tragedy,” he said.

Reflecting the sobering calculus that the FAA and the airline industry employ, Machol said that the 13 deaths in 18 months was not an alarming enough figure to prompt drastic action. “The 13? That’s not much, really,” he said. “We fly about 500 million people a year in the United States, and . . . about 100 (are killed), on average. That’s not a bad number.”

By its own admission, the FAA may have violated disclosure statutes by withholding the records in January and February when The Times requested them. The agency surrendered the records in May after the newspaper appealed the FAA’s initial response to Hinson.

Asked why the records were not released the first time, FAA spokesman Hank Price said: “We’re determined to respond to that question. We’ve launched an internal investigation.”

Machol, who was involved in the FAA’s initial response to The Times’ FOIA request, believes the records may have been deliberately withheld, a charge Price said the agency could not confirm or deny at this juncture.

“I urged them to send it all . . . the first time around,” Machol said. “Cliff Hay didn’t want (The Times) to have them.” Hay is manager of the FAA’s wake turbulence program.

Hay denied opposing the release of any documents. “I had no part in restricting anything,” he said. “It doesn’t do us any good to withhold information.”

The FAA has identified an additional 22 internal documents on the subject of 757 turbulence but refuses to make them public, saying they are exempt under the disclosure law because they “contain advice, opinions and recommendations made by staff members in the course of reaching final positions.”

Besides the documents provided by the FAA, The Times obtained from independent sources an Oct. 3, 1989, memo suggesting the agency was sensitive to public perception on the issue of wake turbulence. The memo, written by Machol and addressed to the FAA’s associate administrators for aviation safety and air traffic, quotes Machol as saying he did not understand why there were not more wake turbulence disasters, given the FAA’s wake turbulence policies.

At the top of the memo, someone had written by hand: “Bob: A note of caution--please watch your wording--I don’t want ‘smoking guns’ in our files.”

Machol, who remembered the memo when interviewed by The Times, declined to identify the author of the handwritten note. FAA officials said they are unable to determine who it was. The FAA’s Broderick speculated that the author of the note simply objected to Machol’s use of “unprofessional” language.

The records that were released by the FAA indicate that Machol, as far back as June, 1990, had urged the regulatory agency to increase spacing between 757s and trailing airplanes. Among them:

* A June 18, 1990, memorandum from Machol to the then-head of the wake turbulence program, citing a wake turbulence incident four days earlier involving a Simmons 206 aircraft and a 757. “We must do something about spacings behind 757s,” Machol wrote.

* An Aug. 8, 1990, letter from Machol to Paul Thomas of Britain’s Civil Aviation Authority in which Machol said the “757 has been the lead aircraft in a startlingly large number of wake-vortex incidents.”

* An Oct. 25, 1993, report by Machol on wake turbulence in which he said: “If the lead plane is a 757 and the trailing plane is a light DC-9 at three miles,” and certain weather conditions exist, “the situation could in my opinion be very dangerous.”

* Another passage in the same report refers to the special meeting Machol requested with high-level FAA officials before the 757-related accidents had occurred and contains his prediction:

“I lectured to the FAA’s associate administrators on Dec. 7, 1992, on wake vortices and predicted a major crash within 10 years, most probably (an) . . . aircraft with tail-mounted engines behind a 757 at a high-altitude airport.”

Eleven days later, the first of the two fatal 757 encounters happened at Billings, Mont., involving a Cessna Citation with tail-mounted engines; the plane involved in the Santa Ana accident a year later, a Westwind, also had tail-mounted engines. Among the five casualties in the Santa Ana crash were the top two executives of the In-N-Out Burger chain.

The National Transportation Safety Board in March urged the FAA to require minimum separation of four to six miles behind 757s, depending on the size of the trailing aircraft. But the FAA’s new policy calls for only a three- or four-mile separation, depending on aircraft size.

The policy may be changed again after completion of tests on the 757 to determine whether more separation distance is warranted.