The Fort Worth Star-Telegram
 

Sunday, March 25, 1984

Design flaw mars Bell

military helicopters

By MARK THOMPSON
Star-Telegram Washington Bureau

(Part 1 of 5)

WASHINGTON — Nearly 250 U.S. servicemen have been killed since 1967 aboard Bell helicopters that crashed because of a design flaw that remains largely uncorrected even though the Army discovered it in 1973, according to military documents and former Pentagon safety experts.

The top lawyer at Bell Helicopter of Fort Worth acknowledged the seriousness of the matter in 1979 when he urged the company to fix the problem even if it had to spend its own money to do so.

"I consider this matter very serious and, if we do nothing about it, very likely to be the subject of attempts at punitive damages." George Galerstein, Bell's chief legal counsel, told company management in a 1979 internal memo.

Galerstein's prediction has since come true — families of five pilots killed since 1980 in crashes attributed to the design problem have filed suits seeking nearly a quarter of a billion dollars In damages from Bell.Since 1970, when Bell lost the first case in which the design problem was cited as a cause, the company has settled all other lawsuits involving the problem out of court. 

Both Bell and the military have long recognized that under certain conditions, Bell's Huey and Cobra helicopters tend to disintegrate in midair as the spinning rotor system teeters too far and cuts into the mast that connects it to the helicopter. The problem, peculiar to teeter-rotor helicopters, is known as "mast bumping." 

The teeter rotor is unlike most other rotor systems because the seesaw-like motion it creates as it spins has definite limits. Unlike other systems, in which this flapping — required by the physics of helicopter flight — occurs safely away from the mast, in the Bell system the rotor hub also teeters. 

Under certain conditions the rotor can teeter so far that it hits the mast, causing mast bumping. Severe or repeated contact can lead to a break in the mast, causing the rotor to fly off the helicopter or slice through the passenger compartment.

Despite repeated pleas by Army safety officials, little has been done to correct the problem in military helicopters. Because of less severe maneuvers done in commercial flying, mast bumping has not been a problem in Bell's civilian helicopters. An internal study done 10 years ago by the Army Safety Center concluded that Bell had made an "error in design" when it built the helicopters around the teeter-rotor system, and it urged the military to stop buying the helicopters because the flaw was "intolerable."

The study was shrugged off by Bell and abruptly dismissed by the director of Army aviation, Gen. William J. Maddox Jr., who recently was hired to run Bell's Asian operations.

The Pentagon, in spite of the problem, is seeking $420 million over the next two years to buy 44 more Bell teeter-rotor helicopters. Defense officials contend current pilot training minimizes the chance of mast bumping, and the fix sought by Galerstein is not cost effective.

Deaths attributed to mast bumping peaked during the Vietnam War. The Army has estimated that an average of six servicemen will die annually as long as the problem remains uncorrected. Actual fatalities in recent years have been fewer than predicted. 

A mast-bumping fatality can occur in as little as one-tenth of a second when a wild rotor blade slashes through the cockpit. The pilots, if not decapitated, usually are killed by the crash and explosion that follow.

In a recent interview, Bell attorney Galerstein stood by advice he gave the company's top officials in his 1979 memo.

"I consider that memo as good advice." Galerstein said. It was offered to help Bell "best protect itself" from suits, he said. 

 Bell contends that it did its part to solve the problem when it turned over to the Army a Pentagon-funded study outlining how a relatively inexpensive hub spring could curb mast bumping. 

The Army has said the hub spring would have saved 60 percent of the lives lost in mast bumping. However the Army, despite pressure from its top researcher who said the device was needed to save lives, chose not to buy it.
"As far as I'm concerned, the company listened to me and did what they could," Galerstein said. However, he conceded that Bell never filed a proposal with the Army to correct the problem — the only recommendation contained in his one-page memo.

While Bell officials said the military's list of accidents being attributed to mast bumping is "grossly inaccurate," the company has never formally protested the keeping of such a list because it might injure relations Between Bell and its biggest customer, they said.

Computer simulations have shown mast bumping does not occur when the helicopters are flown properly, Bell and many military officials said. "Our people are just beside themselves because we don’t think we're doing anything wrong," said a Bell official, who wanted to remain anonymous. "We'd like to light it in court, but our legal folks have felt if we take it all the way — and lose — that the jury awards can be so humongous that we'd be betting the company." 

Bell officials emphasized that the majority of product liability cases are settled out of court and that Bell's decisions to settle constitute no acknowledgement of wrongdoing. 

Knowledge of the problem — generally limited to a small circle of helicopter industry officials, lawyers, military safety officers and pilots — has spread recently after several unexplainable accidents at the helicopter test pilot school at Patuxent River, Md.

Since 1980, five of the military's best helicopter pilots have been killed aboard Bell helicopters that crashed because of mast bumping, according to Navy investigators. 

Within hours of the most recent fatal crash there last year, the school stopped using Bell machines for certain types of flights. The Navy, which runs the school, is seeking replacements for the Bell models.

Bell and many military officials have insisted that mast bumping will never occur unless a critical part fails or the pilot flies beyond the limits set for the helicopter. But the only person to survive a catastrophic mast bumping disputes their contention. 

Col. Larry B. Higgins has told his superiors — and the Star-Telegram — that he was flying a Cobra helicopter within its operating limits last August when a rotor blade sliced through the cockpit, killing his co-pilot instantly. Higgins was able to parachute to safety only because the blade cut off the front of the cockpit, giving him an instant escape route.

Higgins' was the most recent of 67 accidents involving U.S. military choppers in which mast bumping was cited as a cause. His co-pilot's death was the 231st in which mast bumping was cited."The cause of the accident is unknown,” the official Navy investigation concluded. "There are possible unknown factors that may cause mast bumping to occur in flight regimes under which a pilot would not normally expect this phenomenon to occur."

Higgins' survival and his willingness to talk about the crash pose headaches tor Bell and Lloyd's of London, which insures Bell's military machines. Ever since a jury in El Paso in 1970 ordered Bell to pay $600,000 to the widow of an Army pilot killed in a 1965 accident that her lawyers claimed was caused by mast bumping. Bell has settled out of court in all cases involving such allegations. 

The El Paso jury — whose decision later was upheld by a state appellate court — found that the rotor system was "unreasonably dangerous." 

Survival in crashes resulting from mast bumping is virtually impossible, and the deaths are brutal.
In many cases, the severed rotor blade slices through the cockpit, chopping the occupants to pieces. Fuel lines are also cut by the blades, soaking the fuselage with fuel. 

Without blades, the helicopter can't land safely. And since it cannot glide like an airplane, it simply becomes a tailing object, striking the ground with tremendous impact. 

The wreckage usually explodes on impact. 

Some occupants are not killed instantly, however. 

A Marine Corps major was aboard a helicopter at the test pilot school in 1980 when a mast bumping and separation killed his pilot but left him alive. Equipped with a parachute, he pulled his door handle in an effort to bail out, but was unable to open the door. Finally, he broke the handle.

But by the time he was outside the helicopter and had pulled his ripcord, he had hit the ground. An instant later, the helicopter fell on him, according to the Navy investigation. 

In a 1981 Australian crash for which Bell is being sued, the Australian military tried to determine why a helicopter crew chief was unable to parachute to safety.

Investigators suggested that he may still have been shaken because of a troubling flight in the same helicopter the week before. He may have frozen in shock when -- after the mast bumping occurred -- the rotor blade came through the cockpit and decapitated the pilot sitting in front of him. 

"In this accident, the visual scenes confronting him would have been horrific," the investigators said, noting the crew chief had up to 12 seconds to escape. "This, coupled with (his) already high state of anxiety, may well have been sufficient to freeze him in a state of immobile terror."

The problems created by the flaw are compounded by the fact that the correct pilot reaction — once it has been realized that mast bumping has begun — is "counter-instinctive," according to the Army. 

If the pilot reacts normally — the way he always has — death is nearly inevitable. In a helicopter on the verge of mast bumping, the pilot must recall that mast bumping requires a unique pilot reaction and then do it. 

"You may never come into a mast bumping your entire pilot life, but if you do — and you make the wrong move — you're sunk," said Maj. Don Foster, a top Huey program official in St. Louis. 

"You get only one chance at it — if you don’t do it right it's all over," said Larry Bowles, a former test pilot for Bell.
A number of people who have studied mast bumping say the boundaries of the flight envelope — the limits set by Bell and the military — are so blurry, and so easy to cross, that the teeter-rotor design should be modified or scrapped.

Many experts, including Bart Kelley, the retired Bell executive who played a major role in the design of the teeter rotor, think Bell and the military tried to do too much with it. 

When first introduced to the military in the late 1950s, the Huey teeter rotor was built to fly “relatively benign, non-maneuvering mission profiles," a 1981 Navy report noted. But with the onset of the conflict in Vietnam — and the introduction of the Cobra gunship using the same rotor system — little attention was paid to the limits of the teeter rotor.

"Aggressive maneuvering to accomplish combat missions was a natural progression, but not necessarily monitored," the Navy said.

The only thing the military has done to cut down on the chances its helicopters will crash because of mast bumping is to buy rotor masts made of thicker steel — a change one Army official said will delay the loss of the mast from one to two seconds. The military also has issued warnings and made a film concerning the problem.

Strenuous
maneuvers
cause flap

By MARK THOMPSON
Star-Telegram Washington Bureau

(Sidebar to first article)

WASHINGTON — The teeter-rotor helicopter— the backbone of Bell's product line and the Pentagon's helicopter fleet — is one of the simplest rotor systems ever developed.

Across the board, the design — used aboard Bell's UH-1. AH-1 and OH-58 models — is among the safest In use today. Combined with the ease of maintenance associated with having only two rotor blades — most other helicopter designs have more — it seemed a bargain when the Pentagon first bought it 25 years ago.

In the demanding environment now common to military helicopters, even Bell acknowledges that under certain conditions, its teeter rotor tends to bump against the mast that links it to the helicopter.

Severe or repeated bumping of the hollow mast by the rotor system dents it, and — like a soda straw that has been crimped — dramatically reduces its strength.

Unlike other helicopters, the two blades in the Bell Huey and Cobra systems are rigidly linked together In a straight line, bisected by the mast. While blades on other systems are hinged to the rotor hub to ensure the mast and rotor hub remain at a 90-degree angle, the Bell rotor hub flaps — teeters — about the mast as the aircraft flies.
The physics of the system requires this flapping to assure stable flight.

On most such Bell rotor systems, the blades can teeter 12 degrees from level, and 90 percent of the time the blades remain within 4 degrees of level.

But when the strenuous maneuver common to combat are performed, additional forces on the rotor cause it to flap even more. Various mechanical failures or sudden weather changes also can spark excessive flapping.


Monday, March 26, 1984
Army, Bell
downplayed
copter flaw
  

By MARK THOMPSON
Star-Telegram Washington Bureau
 

(Part 2 of 5) 

WASHINGTON — It wasn't until 1973 — after the Vietnam War had begun winding down — that Army safety officials began to suspect that something was wrong with their Bell helicopters.

Crashes had occurred in Southeast Asia and elsewhere in which the main rotor system was found far away from the wreckage of a helicopter — indicating the two had separated high in the air.

"Over the years we'd had these mast separations, but it wasn't until some of our old-timers at the safety center got involved that we began to think it was statistically important," recalled F. M. "Max" McCullar, a retired Army colonel who was head of the Army Safety Center at Fort Rucker, Ala., in 1973.

"I was convinced right off we had a real problem," McCullar said recently.

After reviewing crashes of Bell helicopters, the safety center issued a report in 1973 that concluded "mast bumping" was to blame in 47 crashes and 181 deaths. The investigation revealed that 27 of the crashes occurred as the helicopters, built in Fort Worth, were in "normal cruise flight."

"We figured this was just the tip of the iceberg," said Sam Kalagian, now retired from the No. 2 spot at the safety center. "Who knows how many happened in Vietnam where we were in the habit of writing on everything as a combat loss?"

Mast bumping occurs In Bell's Huey and Cobra teeter-rotor helicopters when aerodynamic forces push the base of the free-floating main rotor too close to the mast on which it is mounted, allowing it to chew into the mast. In most cases, once mast bumping begins, the mast will snap and the rotor will either fly off the aircraft or slice through the cockpit, dooming the helicopter and its occupants.

Pentagon safety officials have cited mast bumping as a cause in 67 Bell helicopter accidents that killed 231 servicemen since 1967. Bell faces nearly $250 million in wrongful death suits alleging that Bell knew of the mast-bumping problem, but did not correct it.

The recommendations contained In the safety center's report In 1973 were as blunt as they were unlikely to be accepted by a military hierarchy dependent on helicopters to fight the war in Vietnam.

The panel urged that "further procurement of the teetering rotor system of the design currently in the Army aviation inventory (UH-1 and AH-1G) not be considered....

"This type main rotor system has unstable characteristics that cannot be tolerated," the safety center said. "It is further concluded that the manufacturer has committed an error in design..."

Neither Bell nor the Army director of aviation shared McCullar's concern.

"We pointed these things out to Bell and some of their people right in my office at Fort Rucker before I went to the Pentagon and got completely, what I'd have to say, was a negative reaction," McCullar said. "They kind of shrugged their shoulders — they didn't think it was their responsibility."

So. McCullar in November 1973 took the report to Gen. William J. Maddox Jr., then the top man in Army aviation and McCullar's immediate boss.

"We told him how many had crashed due to mast bumping, and what we thought were the reasons," McCullar said. "He said, 'Well, a lot of them haven't crashed,' which was true. 'Next subject' — that's what he said — I remember it distinctly."

The entire discussion took less than a minute. McCullar said.

Maddox — whose son has worked at Bell since leaving the Army in 1980 — was hired by Bell last year to head the company's Asian operations. From his office in Singapore, he said he didn't recall meeting with McCullar on the topic, and said any decision he may have made had nothing to do with his ending up at Bell several years after his retirement from the Army.

"Whatever decision I made in the Army on any report was colored by my experience and professional background, and I hope my military judgment — it was not related to an affiliation with any particular manufacturer," he said. "The safety people make a lot of recommendations that are not accepted by top management."

Maddox, noting that military pilots each year log thousands of hours In Bell teeter-rotor helicopters, contended that mast bumping really isn't a "major problem."

Rebuffed by Maddox, Army safety officials were limited in what they could do to reduce mast-bumping accidents.
"We brought it to the attention of commanders and pilots any way we could," McCullar said. "We told them to fly the helicopter very carefully — that was about all we could do."

By 1976, the Army — after repeatedly instructing its officials not to talk about the problem to outsiders — got a scare when a congressional aide began looking into a mast-bumping crash in which a friend was killed In Virginia.
He set up a meeting with a Bell representative in Washington and was stunned by what he was told.

"I will never forget the meeting — Bell took the position that essentially these things happen,” recalled James MacInerney, now a consultant in Washington.

"It just sort of sent me up the wall — they showed great insensitivity," MacInerney said. But assured by Bell and the military that the problem was being solved, he moved on to other things.

His interest put the Army on guard. Both a congressional investigation — and the mast-bumping problem — "could have some damaging impact on Bell's competitive entry against Hughes for the new Advanced Attack Helicopter," an Army official said in an internal memo.

"We must use great care to ensure that we control what's being disseminated and that we all say the same things," he added.

Maj. Michael Stratton, an Army engineering test pilot, worked at the safety center when Maclnerney inquired about mast bumping, and recalled the Army's reaction.

"They had a purge at the safety center of everybody's desk of all the information they had on mast bumping,” he said. Everyone was ordered to direct all questions on the problem to the safety center's legal staff.

In 1977, the safety center decided to issue a training film on mast bumping.

"There was a high degree of concern about getting the word out to pilots because we felt the accidents would continue if something wasn't changed," said Dr. James Hicks, who worked there when the film was made.
After putting the 20-minute film together, the safety center sent it to Bell for reaction.

While Bell's anonymous reviewer pointed out technical errors, he also repeatedly took issue with the Army's claim that excessive blade flapping—which can lead to mast bumping in teeter rotors — is any different than the blade flapping that occurs on other types of helicopters.

"The flapping described In this film applies to all types of rotors." the Bell reviewer told the Army. He neglected, however, to say that only in teeter rotors does excessive flapping lead to a number of deaths because of the system’s design.Bell also objected to the Army claim that under certain conditions a competing rotor system was better and safer.

"These comments are irrelevant to the problem of mast bumping," the Bell reviewer said.

The Army changed the film in response to Bell's complaints — making "substantial accessions" — but didn't give Bell everything it sought, Hicks said.

"They wanted to make a point that this cannot happen within the flight envelope (the limits of flight set by Bell and the military) — they just wanted to say this very, very directly and make that kind of the theme of the film," he said. "They wanted to state it a little more slanted toward the standpoint of protection from product liability and we didn't go along with that.

"We didn't want to overly assure pilots," Hicks said.

"The film was developed by the Army," George Galerstein, Bell's top lawyer, said recently. "Nobody forced any editing on the Army."

But Galerstein did warn top Bell officials in 1979 that — despite Army efforts — lawyers representing widows of pilots killed in mast-bumping crashes probably would be able to obtain a copy of the film and use it against Bell in court.

In an Internal Bell memo, a Bell engineer in 1978 told his superior that although Bell experts "do not agree with every technical detail of the film as it presently exists, the general theme should come across as, 'The helicopter must be operated within its prescribed center of gravity and other limits.'"

But operating within those limits is difficult when the pilot doesn't have the tools to monitor them.

The Army has ignored repeated requests by safety officials to install a G-meter aboard the aircraft to warn pilots when mast bumping might be imminent. Low-G situations — where the helicopter approaches "weightlessness" during vigorous maneuvers — are among the prime causes of mast bumping.

A Bell official told an Army officer that Bell military helicopters aren’t equipped with a gauge to measure sideslipping — another flight condition known to contribute to mast bumping. "It would be difficult to expect a pilot to stay within specified sideslip limits when he doesn't have a true sideslip indicator to monitor," the Bell official said in a letter.

A Navy official who asked not to be identified said the Navy test pilot school toyed with the idea of Installing a system to warn its pilots of impending mast bumping, but scrapped the idea when they discovered how quickly mast bumping takes place.

"The close approach of mast bumping happens so fast that no one could ever do anything physically about it,” he said. "The warning light would come on at the same time the rotor blade's coming through the cockpit."



Tuesday, March 27, 1984

Bell blames pilots;
inquiry faults copter

 

By MARK THOMPSON

Star-Telegram Washington Bureau 

(Part 3 of 5) 

WASHINGTON — Douglas L Dowd, a native Texan with a doctorate in aerospace engineering from the University of Texas at Austin, knew all about mast bumping on Bell helicopters. But that knowledge did not save his life.

Serving as the senior helicopter instructor at the military's only helicopter test pilot school in Patuxent River, Md., Dowd, an Army major, had collected an impressive array of honors: distinguished graduate of both Army and Navy flight schools, distinguished graduate of the ROTC program at West Texas State University, and selection by the military as a potential astronaut.

On May 26. 1981, flying a Bell AH-1S Cobra, Dowd and his student test pilot were killed instantly when their craft exploded in midair. A military investigation later attributed the explosion to mast bumping. Mast bumping results from a design detect peculiar to Bell teeter-rotor helicopters. When it occurs, the rotor hub chews into the mast on which it is mounted, frequently snapping the mast and sending the rotor flying off the craft or slicing through the passenger compartment.

When his helicopter exploded. Dowd was at the controls, an autopsy report shows.

Witnesses — supported by radar records — said the Fort Worth-built helicopter was flying "straight and level" when it exploded.

"All evidence indicates that the mishap flight was normal in every respect until a sudden event or series of events precipitated mast bumping and its catastrophic consequences." a report of the Navy investigation of the crash said.
Dowd's superiors at the flight school plainly were upset by his death.

Dowd, they said in a cable to the chief of naval operations at the Pentagon, "was a key member of an aircraft mishap board which investigated a similar mishap in an OH-58A six months before."As senior rotary wing instructor, he was responsible for increasing aircrew awareness of mast-bumping phenomena and had written a precis on the subject," the cable said.

Dowd, officials added, "had a reputation as a thoroughly professional and conservative pilot."

The Pentagon has cited mast bumping as a cause in 67 accidents involving Bell helicopters. Those accidents killed 231 servicemen, and Bell is facing lawsuits seeking almost $250 million in damages in connection with those crashes.

Bell and many military officials say mast bumping cannot happen while the helicopter is flown properly. Others — including the only man ever to survive such an accident — contend otherwise.The military has known of the perils of mast bumping since 1973, when the Army Safety Center issued a report sharply critical of the helicopters' design.

 And Bell's top lawyer, George Galerstein, warned company officials in 1979 of the helicopter's "tendency to 'mast bump' and separate" and urged management to move quickly to fix the problem or risk lawsuits.

Little, however, was done in response to either warning.

The Navy — alarmed at the two fatal helicopter crashes in which the cause ultimately was listed as "unknown" — began taking a closer look at mast bumping.

The Navy checked its records and those of the Army and found that neither service had any data outlining the mast-bumping risk that helicopters encounter during certain maneuvers.

"The insidious nature of mast bumping is due to the tact that mast bumping can be caused by a diverse range of conditions," Navy officials told the Pentagon in August 1981. "Most of these may occur without any clearly discernable clues to the pilot that blade-flapping angles are approaching catastrophic limits."

The Navy investigators recommended that the test pilot school replace its teeter-rotor craft with another type of helicopter "as soon as possible to remove the inherent mast-bumping hazard associated with helicopter flight test training."

Another mast-bumping accident at the test pilot school last August yielded the first survivor of such a crash. He repeatedly has said that he and his co-pilot were operating the aircraft properly when the crash occurred. In the wake of his testimony, the test pilot school stopped using Bell helicopters on its more demanding flights and is seeking to replace them.

Despite the Navy's findings, Bell lawyers contend the crashes were the fault of the pilots.

Galerstein, in a recent Interview, stressed the teeter rotor's safety record. The Bell teeters in 1983 had a lower accident rate than any other helicopter in the Navy, Pentagon records show.

The Bell attorneys contended in a court filing that the first test pilot school accident In November 1980 — the one that Dowd helped investigate — was not caused by mast bumping but by "rotor-fuselage interaction" sparked by pilot "mishandling" of the controls. The second accident, in which Dowd was killed, was due to the "deliberate operation by the pilots outside clearly published operational limits" of the helicopter, Bell's attorneys asserted.

"It makes our blood run hot — they're challenging the professional expertise of the guys who teach this art,” said a test pilot school official who asked not to be named. "If we don't know what we're doing...nobody else does."

Dr. James Hicks of the Army Safety Center in Alabama also disputed Bell's contentions.

"The contractor is saying that they're just horsing around,” he said. "I just cannot believe that is happening."

But Bell and other military types are quick to point out that the flights at the test pilot school aren't normal.
"They test airplane limits at Patuxent River — that's their job,” said Col. Thomas Walker, director of maintenance for Army helicopters. "We don't pay those guys to go up and fly straight and level."

Operational Navy pilots — aviators who don't do test flights in the helicopters — are convinced no trouble can come to a pilot who flies within the limits established jointly by the military and the manufacturer. Those limits are described as the flight envelope.

"The Navy and Marine Corps have examined the problem of mast bumping and have determined the areas where you're most likely to get into problems — we just don't go into those areas," said a top Navy pilot selected by the service to answer a reporter's questions on the subject.

"Who in the world is going to get into that situation on purpose?" he asked. "It you're that stupid, you deserve to die." 

James Hunt, a New York lawyer representing Bell in the mast- bumping cases, believes it's not coincidental that most recent mast-bumping crashes have occurred at the test pilot school.

"They're pushing the thing to the point where there's very little leeway if they go too far," said Hunt, who piloted a Bell-built Cobra helicopter in Vietnam.

Cmdr. James Loiselle — who holds the senior helicopter test pilot instructor post once held by Dowd — insisted all of the work done aboard helicopters at the test pilot school Is within proper limits.

"We don't define any envelopes here at the school — we work within all the envelopes," he said. "It you get mast bumping you've got some problems — and I think it's very easy to get there from points inside the envelope."

Capt. Robert Parkinson, the head of the test pilot school, said all of the test flying done there is done inside the envelope.

The causes of the three fatal accidents remain "undetermined," he said, although Bell and the flight school continue to study the problem.

William J. Maddox Jr., a former top Army aviator who now heads Bell's Asian operations, questioned any claim that the Patuxent River pilots knowingly stray beyond the flight envelope.

"Test pilots are a very dedicated and meticulous group of pilots and they're carefully selected before they even get into it," Maddox said. "They go through a very rigorous training program and they know as much about flying as anybody in the flying business."

"They are professional men, very proud of their abilities." added Hunt, the Bell lawyer. "But, unfortunately, test pilots have been killed in a lot of things. Not just helicopters, not just Bell helicopters."

Wednesday, March 28, 1984

Pilot lives
to describe
helicopter
crash
  

By MARK THOMPSON
Star-Telegram Washington Bureau
  

(Part 4 of 5) 

WASHINGTON — Last Aug. 19, Majs. Larry B. Higgins and James M. O'Brien lifted off at 9:40 a.m. in their Bell helicopter from the Pentagon's helicopter test pilot school at Patuxent River, Md.

Higgins — who had finished first in his class in 1978 and was then the school's third-highest-ranking official — was demonstrating the AH-1S aircraft to O'Brien, who was training to become a helicopter test pilot.

Aboard the Cobra gunship — only 36 inches wide — the pilots sit one behind the other instead of side-by-side as in most other helicopters. Higgins, as the pilot in command, was in the front seat. 

At 8,500 feet, they broke through the morning haze that often floats above the Chesapeake Bay and began doing the maneuvers required by the published outline of the training flight.

Higgins was instructing O'Brien on the use of the pedals to help control the helicopter. Holding a limiter on his pedals, Higgins was restricting how far O'Brien could push his. Linked together, the pedals can be controlled by either pilot.

Higgins told O'Brien to push his right pedal a half-inch.

O'Brien counted down and depressed the pedal. Even though Higgins hand-held the limiter at a half-inch, O'Brien managed to depress the pedal farther — "maybe three-quarters of an inch," Higgins recalled.

The helicopter immediately began to roll to the right and entered a dive. Higgins let go of the limiter and grabbed the controls.

"I was on the controls maybe a second — something hit the front canopy and there wasn't much front canopy left," Higgins told Navy investigators later that day.

"I assume that the rotor blade had hit the canopy, shattered the canopy, the rails and the Plexiglas all over the place," he said. "It appeared to me at that point that I was no longer really with the aircraft — there wasn't much to fly at that point so I unstrapped."

Higgins yanked his rip cord — parachutes are mandatory on most test flights at Patuxent River — and began floating to safety, casting an anxious eye about for O'Brien and the helicopter.

"Didn't see any other 'chutes; didn't immediately see an aircraft; saw a lot of pieces of things floating around, like, I don't know, just pieces of things floating around," he recalled.

Within minutes, he was on the ground and was escorted to a nearby road by a passer-by who had seen his parachute.

"The Calvert County (Md.) rescue squad was there," he told accident investigators. "I guess that's about all I have to say."

According to Pentagon records and officials, O'Brien — sitting behind Higgins — was killed instantly by the rotor blade that smashed through the cockpit. Miraculously, the blade also flung a badly cut — but alive — Higgins into space.

O'Brien was the 231st U.S. serviceman to die in a Bell helicopter accident later blamed on a defect that has become known as "mast bumping."

Higgins, on the other hand, was the first ever to survive a helicopter accident resulting from mast bumping.

Mast bumping occurs in Bell Huey and Cobra teeter-rotor helicopters when the free-floating blade, pushed by aerodynamic forces, teeters too far, causing the hub to chew into the mast on which it is mounted. Such a bump can cause the mast to snap, sending the rotor flying off the craft or slicing into the passenger compartment.

The Army was first alerted to the problem of mast bumping in late 1973 and subsequently awarded three contracts to Bell to find a solution to the problem. At the close of the final study, Bell's top lawyer, George Galerstein, cautioned Bell officials to fix the mast-bumping problem or risk massive damage suits.

However, Galerstein defended the teeter rotor's safety record in a recent interview. Pentagon records show the Bell teeters in 1983 had a lower accident rate than any other helicopter in the Navy.

Bell and many military officials contend mast bumping cannot happen it the helicopter is flown properly, but Higgins — now a lieutenant colonel — disagrees.

His testimony could prove critical in any of several multimillion-dollar lawsuits seeking a total of about $250 million from Bell. The suits claim that the Fort Worth helicopter builder knew of the dangers posed by mast bumping years ago and did nothing to solve the problem.

Higgins has maintained to military investigators that he and O'Brien were operating the helicopter within proper limits when the accident occurred.

"The mast-bumping phenomenon encountered by Maj. Higgins was absolutely unexpected by him at the time and cannot be explained by available evidence," an inquiry into the accident by Navy investigators concluded. O'Brien's three-quarter-inch pedal push was well within allowable limits, the investigators said.

"There are possible unknown factors that may cause mast bumping to occur in flight regimes under which a pilot would not normally expect this phenomenon to occur," the investigators said.

In the wake of the Higgins-O'Brien accident, the test pilot school, which is the Pentagon's only such facility, immediately ceased using Bell teeter-rotor helicopters for demanding exercises and is seeking replacements, according to Navy officials.

A former top Bell official, now working elsewhere, believes that Higgins could cause trouble for Bell, which, as always, maintained that mast-bumping accidents are attributable to pilot error.

"The survivor presents a problem for Bell." he said. "I think the company's vulnerable."

"I'm not saying that Maj. O'Brien is dead because of what Col. Higgins did or didn't do, although I really think that's what happened," said James Hunt, a New York lawyer representing Bell in mast-bumping cases. "We are going to say that — if we are forced to — because if somebody sues us they're going to force us to defend ourselves."

The O'Brien family has not yet decided whether to sue Bell, according to a New York attorney representing the family in the matter.

George Galerstein, Bell's top in-house lawyer, agrees that human error was the cause. "We have studied the record and the pilot had put himself in an absolutely untenable position," he said.

"I read Higgins' statement, and I think there's a lot of ambiguity in it," Hunt said.

"I wouldn't be surprised it his subsequent statements changed more, I might say, in his favor," he said. "He wouldn't be human it that didn't happen."

Higgins reacted coolly to Bell's claims. "My statements as far as the occurrences leading up to that accident remain the same," he said recently. "I don't have a different recollection of it now than I had previously, and the circumstances surrounding that particular incident are still pretty well current in my mind — I haven't changed my story."

Higgins said that during a meeting with Bell officials at the helicopter test school, he gave them the same statement. At that meeting, Bell officials detailed for Navy officials their theory of how the crash occurred. Higgins contended that Bell's description showed he was flying the aircraft within its prescribed operating limits when the mast bumping started.

He rejected Bell's claim that he exceeded the helicopter's operating limits — known as the "flight envelope."

"They are correct — the aircraft ended up outside the flight envelope, that's correct," he said angrily.

"It's not in the envelope to separate the hub (from the mast),” Higgins said. "That's a result of aerodynamic forces operating on the aircraft while the aircraft was being flown within operational limits.

"I did not operate the aircraft outside the flight envelope — nor did Maj. O’Brien," he said.

 

Widows hope suits
will help end
copter problem

By MARK THOMPSON
Star-Telegram Washington Bureau

(Sidebar to fourth article) 

 WASHINGTON — Donna K. Dowd first became concerned for the safety of her helicopter pilot husband, Doug, when he told her about the crash that had killed a good family friend.

Dowd, an Army major, had been investigating a November 1980 helicopter accident that had killed Cmdr. Larry Ammerman and his student instructor pilot at the Pentagon's helicopter test pilot school at Patuxent River, Md.
Donna Dowd said her husband told her that the accident, involving a teeter-rotor Bell OH-58A, had resulted from a phenomenon that has been dubbed "mast bumping."

"I was terribly upset over Larry's death." Donna Dowd recalled recently. "For the first time in my life I was fearful for Doug to fly."

She pressed her husband tor details about mast bumping, a condition generally encountered only aboard teeter-rotor helicopters that Fort Worth's Bell Helicopter has sold to the Pentagon tor the past 25 years.
"I remember asking him. 'Well, what do you do it you mast bump?'" she said.

"He said. 'Well, you're usually dead,'” she said. "He put it very bluntly that once you mast bumped you didn't have a chance.

"I recall at the time thinking of how scary that was — that there was nothing a pilot could do," Donna Dowd said.
Six months after the Ammerman accident, in May 1981, Doug Dowd and his student test pilot were killed instantly during a routine introductory flight aboard a Bell Cobra at the test pilot school. The Navy, which operates the test pilot school, ruled that Dowd's craft had been the victim of mast bumping.

Donna Dowd. a native of Midland, has sued Bell, seeking more than $120 million in connection with her husband's death. The case, pending in federal court in Maryland, could come to trial by this fall.

"By suing — if enough pressure is put there — eventually the helicopter will have to be redesigned," she said. "My feeling is that it people had done this 10 years ago my husband would still be alive."

Mast bumping occurs in Bell teeter-rotor helicopters when the free-floating blade, pushed by aerodynamic forces, teeters too far and its hub cuts into the mast connecting it to the helicopter. That can cause the rotor to fly off the craft or send it slicing into the passenger compartment.

The Pentagon has cited mast bumping as a cause in 67 accidents involving Bell aircraft, resulting in 231 deaths since 1967. Five lawsuits pending against Bell seek nearly $250 million in damages in crashes blamed on mast bumping. Bell already has lost or settled all lawsuits involving mast bumping.

George Galerstein, Bell's top attorney, defends the teeter rotor's safety record. The Bell teeters in 1983 had a lower accident rate than any other helicopter in the Navy, Pentagon records show.

While Bell and many military officials contend that mast bumping cannot occur when teeter-rotor helicopters are flown properly, the widows of pilots killed in mast-bumping accidents — bolstered by the testimony of the lone survivor of such an accident — believe otherwise.

Lynda K. Baker's husband, David, died with Ammerman in the 1980 crash. According to sources on both sides, she and her three children last fall agreed to accept a multimillion-dollar settlement from Bell — spread over at least 30 years — in exchange for dropping their suit.

"I have many scornful and hateful feelings toward Bell because I know Bell had the technology to fix this problem that keeps taking lives," Lynda Baker said, referring to a restraining hub spring designed by Bell to curb mast bumping.
Bell officials ignored a plea by Galerstein in 1979 to install the hub spring on Bell military helicopters, even if Bell had to absorb the expense.

"I feel Bell has silently acknowledged that this problem exists because they settled, even though they won't do anything to fix it," said Lynda Baker, who now lives In Virginia.

She recalled the pressure she received from military officials who did not want her to sue Bell.

"They told me to leave it alone — to live with my happy memories — that there was no sense in digging up the deaths," she said. "An admiral who I came to know through my parents — who had been the head of the test pilot school at Patuxent River — stood on his head almost trying to get me to stop the suit."

According to Lynda Baker, the admiral gave her a copy of a 1972 study Bell had done highlighting the company's efforts to solve the problem.

"He just wanted to assure me that Bell was working on it, but it didn't convince me," she said. "I filed the suit because it was an effort to talk the only language Bell understood."

Donna Dowd, now living In Atlanta, made the same point. "Unfortunately, the American system is set up in such a way that unless you hit the pocket book, nothing will be changed," she said.

"l think in pure economic terms, it's cheaper to pay off a couple of widows every year than redesign the rotor system," said Rignal Baldwin Jr., an Annapolis, Md., lawyer who handled Lynda Baker's case.

"What's really upsetting is that Bell wants the problem to tie solved with taxpayers' money," said John Green, an Odessa lawyer representing Donna Dowd, referring to Pentagon-funded contracts Bell has received to study the problem.

Lawyers such as these are aided in making their cases by a number of former Army safety officials who contend that the teeter rotor is unsafe when forced to fly any but the most simple maneuvers.

"They're asking the rotor system to do too much." said Eugene Conrad, a retired colonel who headed the Army Safety Center at Fort Rucker, Ala. Now he and several other men constitute the Accident Prevention, Investigation and Analysis Co., adjacent to Fort Rucker in Daleville, Ala., which has looked into several accidents of presumed mast-bumping cases.

Col. Joseph Koehler, the current chief of the safety center, disagrees. "I really don't believe we have a mast-bumping problem anymore," he said.

However, he acknowledged the hub spring might save some lives.

"The death of one person affects many lives, and even one life ended needlessly is enough reason to change," Donna Dowd said. "Every time one of those helicopters crashes, it's not just the men who die who are affected," she said. "So many other people's lives are affected — wives, children, parents."

Her lawsuit — while seeking damages — also is meant to encourage Bell and the military to correct the problem that resulted in mast bumping. Donna Dowd said.

"I'd feel in some way feel like my husband's life will have been justified if I can bring about that change," she said.


Thursday, March 29, 1984
 

Bell faults
military for
copter
problem

By MARK THOMPSON
Star-Telegram Washington Bureau

(Part 5 of 5)

WASHINGTON — The U.S. military has been asking Bell helicopters to fly increasingly more demanding missions, but the Pentagon has been unwilling to pay for modifications necessary to ensure that those missions can be flown safely, a top Bell official said in sworn testimony last fall.

The testimony was given by Philip C. Norwine, Bell's vice president tor market development, in connection with a suit died by two widows of pilots killed in a helicopter accident blamed on "mast bumping."Mast bumping Is a phenomenon peculiar to teeter-rotor helicopters and can result In the aircraft's rotor flying off and slicing through the cockpit.

Bell has proposed two modification methods designed to help eliminate mast bumping: refitting the military's teeter-rotor helicopters with four rather than two-blade rotors or adding a hub spring device to the present rotor system. However, the military has declined to accept either method because of the cost.

"The UH-1 and AH-1 were designed to certain specific maneuver criteria which were deemed by the Army to be adequate tor the operational needs in the period in which they were developed," Norwine said in a deposition. Until 1981, Norwine supervised Bell's sates to the Pentagon.

"Subsequent technical requirements, for tactical reasons, have evolved into a new set of maneuver criteria which involve flight at zero and negative G," Norwine said.

 "The Army has not been receptive to possible methods of modifying the helicopter so that the existing inventory could accommodate the new criteria, feeling that the rework or cost of modification was not worth the improvement in tactical capability." Norwine said. He was questioned in connection with a November 1980 crash at the military's only test pilot school at Patuxent River. Md., in which Larry Ammerman and David Baker were killed. That suit was settled out of court last November, and details of the multlmillion-dollar settlement are sealed.

The military's desire to push its Bell Huey and Cobra helicopters to the limit has led to catastrophic mast bumping, officials at the Fort Worth helicopter company said.

"There is an awful lot you can do in the flight envelope (the operational limitations of the craft as set forth by the manufacturer and the military). It (the teeter-rotor helicopter) is a very agile and versatile machine." said George Galerstein, Bell's top lawyer. "But no matter what your limits are you can exceed them."

"We're convinced the Army flies them outside the envelope," said a high-ranking Bell official who asked that his name not be used.

Because of their contention that military pilots frequently fly its Bell helicopters beyond the stated operational limits, Bell officials bitterly protest Pentagon calculations showing that mast bumping has killed 231 servicemen aboard 67 Bell helicopters since 1967.

"The Army has put together a list of accidents and said. 'These are mast-bumping accidents.'" Galerstein said. "But that's very misleading."

"It there were a problem, we would have fixed it: it's our policy," Galerstein said.

Bell officials argue that mast bumping only occurs after a critical part tails or after the pilot flies beyond the helicopter's limits.

If a critical part fails, the helicopter is doomed, regardless of mast bumping, Bell officials said.

And no aircraft can be designed to operate safely outside of its prescribed limits.

Once a teeter-rotor helicopter accident sequence begins, mast bumping often occurs even though it was not the precipitating cause of the mishap, Bell officials said. Yet, the company contends, the Army often pinpoints mast bumping as the cause of the crash.

Galerstein and other Bell officials said that the military's willingness to cite mast bumping as the culprit in many accidents is "grossly inaccurate," "total misinformation" and "unfair."

"Mast bumping is the signature of a two-bladed rotor." Galerstein said. "It's highly visible and easily identifiable."
When investigating accidents, the military tends to jump to conclusions when it finds evidence of mast bumping, regardless of where it happened in the crash sequence, Galerstein said.

"Because it's a highly visible signature, the Army then says: 'Mast bumping!'" he said.

Mast bumping occurs in Bell teeter-rotor helicopters when the free-floating blades, pushed by aerodynamic forces, teeter too far and cut into the mast connecting the rotor system to the helicopter.

 While both Bell and military officials acknowledge mast bumping can be curbed, both sides agree that neither has been willing to absorb the cost of the modifications necessary to prevent it.

For several years Bell officials — including former Bell President James Atkins — tried without success to convince the Pentagon to replace the two-bladed rotor systems on the military's Cobra and Huey models with a safer four-bladed system. Such a switch would eliminate mast bumping, Bell officials said.

Bell, with Pentagon money, also perfected a hub spring device for use on its two-bladed aircraft that would cut fatalities due to mast bumping by an estimated 60 percent.

But the military rejected both proposals, deeming each too expensive. Meanwhile, Bell officials ignored a suggestion from Galerstein that the company consider absorbing the cost of adding the hub springs.

"There just weren't enough bucks,” said Story C. Stevens, a retired general who headed the Army's research program in 1979. He told his colleagues in letters then that the "hub spring Is highly desirable in terms of lives and dollars."

"That was the best fix the development community could come up with short of retrofitting the entire fleet with the four-bladed rotor." Stevens said recently.

But despite pleas from Stevens and others, the military officials responsible for improving existing aircraft have repeatedly rejected the idea of adding the hub springs.

"Obviously, the upper echelon in the Army doesn't think it's worth all the money," said G. Thomas White, the Army engineer most involved with the hub spring. The cost per aircraft of installing the device would be about $12,000, White said.

"The problem is being resolved through training and educating the aviators to avoid mast bumping," an Army spokesman said.

"We don't own the airplanes. What can we do? We can't take them and fix them ourselves," a Bell official said.
"We were concerned — our people aren't callous — and the Army apparently was concerned, too, but on balance, they said 'no,' " he said.

In a recent interview, Galerstein stressed the teeter rotor's safety record. The Bell teeter rotor helicopters in 1983 had a lower accident rate than any other helicopter in the Navy, Pentagon records show.

The Navy records show that last year the Bell H-1 series had a lower overall accident rate than the service's Boeing Vertol, Kaman or Sikorsky models.

In the civilian sector, Bell's teeter models have rotor-failure accidents only half as often as non-teeter-rotor systems, government data show.

Although most Bell civilian helicopters are not equipped with hub springs, a few are — an addition Bell officials said is designed to give users greater freedom in how to load the craft rather than for safety.

Nonetheless, mast-bumping accidents continue to occur in military helicopters, and lawsuits continue to be filed against Bell contending the company is aware of the problem and should have fixed it long ago.

 Although Bell has settled all cases in which mast bumping was alleged since it lost the first such case in 1970, lawyers for the firm hinted that they may begin taking a tougher line on five pending mast-bumping cases.

"We are not willing to settle mast-bumping cases," Galerstein said. "There is no case I will settle on mast bumping because it is not a problem."

But setting a lawsuit often makes sense, said James Hunt, Bell's New York attorney.

"Lawyers to a certain degree are businessmen — they report to businessmen," Hunt said. "If we can settle death case for $50,000 — or try it for $150,000 — it makes sense obviously to settle it." Hunt said.

"It's like anything else — it's always a matter of dollars and cents." Hunt said. "It's all money, and it all comes down to dollars and cents."

While Bell officials acknowledge that they have answered those questions to their satisfaction, military officials have begun asking them anew since the most recent mast-bumping accident last August.

That crash yielded the first survivor ever of a catastrophic mast-bumping incident. That survivor contends that he and his co-pilot, who was killed in the accident, were flying the helicopter properly when the crash occurred.

"What we've been confronted with in the past is standing at our office window and watching the helicopter take off with what we knew to be well-qualified crews, and 20 minutes later being told the airplane had crashed," said an official at the Patuxent River test pilot school. Five top helicopter pilots have been killed at the school since 1980 In accidents attributed to mast bumping.

"We'd find the crew dead. and we could only examine the accident from the remaining evidence." said the officer, who asked that his name not be used.

"We knew these things were falling to earth, but we didn't have any idea what precipitated it," he said.
"Now we know," he concluded. "We’ve got a survivor — at last — to tell us."