Most of the PCN has heard about and
read this story, with the best version published in the Reader’s Digest. Delta Capt Jack McMahan certainly qualifies
as an Aviator’s Hero by his many flying exploits. But none of those events surpass what was
accomplished by him and the crew on April 12, 1974. Here below is the Washington Post version of
Flight 1080.
The Saving Of Flight 1080
ITS NEARLY MIDNIGHT at the San Diego
airport as the Delta Air Lines jet accelerates down the runway, bound for Los
Angeles.
When it hits 126 knots, the plane
unexpectedly noses up before the pilot pulls on the control column for takeoff.
Speeding into the heavy clouds over the ocean, the nose pitches even higher.
The amazed pilot desperately slams the control column forward as far as
possible to try to force the nose back down.
This was the beginning of Delta
Flight 1080 on April 12 last year. It was also the beginning of one of the most
harrowing 55 minutes in recent aviation history. The story has a happy ending.
After a series of potentially disastrous maneuvers, the plane landed safely as
Los Angeles International Airport. Although the passengers had been told of a
control problem, they never learned how close they had came to tragedy. Indeed,
at least one of them was furious about being delayed.
The story of Flight 1080, as it
turned out, illustrates how much airlines safety has improved in recent years.
Tragic crashes still occur, like the one in San Diego last month that killed at
least 150 people. But improvement in overall safety records is clearly shown by
statistics of the National Transportation Safety Board.
According to the board's figures,
the number of fatal accidents per million commercial aircraft miles flown
ranged between .007 to .012 up until 1965. For the next decade, safer jets
brought the range down to .003 to .005. During the last three years, it's come down
even further to .001 to .002.
More reliable aircraft engines,
backup control systems built into the newer planes and generally better
air-traffic control are some of the major reasons for the improving records.
Still, even the best of systems has its flaws and loop-holes, and in the end,
passengers' lives often depend on the skill of the pilot up in the cockpit. The
crash of two jumbo jets on the runway on Tenerife in the Canary Islands last
year, killing 579, was blamed on a pilot in a KLM Royal Dutch Airlines plane
who tried to take off without getting proper clearance. In the case of the San
Diego crash, Pilots of the small private plane and the Pacific Southwest
Airlines plane had been warned of each other's presence, but the two planes
inexplicably collided anyway.
ON DELTA'S Flight 1080 leaving San
Diego, the passengers were lucky enough to have Jack McMahan at the controls. A
burly, affable 56-year-old, he is one of Delta's most experienced captains.
During 36 years of flying, he has piloted biplanes, Grumman Wildcats (as a
Marine Corps pilot during World War II) and over a dozen passenger planes,
including all models of jumbo jets.
On Flight 1080, Jack McMahan was
piloting a Lockheed £1011 wide-body. Although the Lockheed plane carries up to
293 passengers, only 41 were on board the night. Eight stewardesses were
aboard, and in the cockpit were Wilbur Radford, the copilot, and Steven Heidt,
the engineer.
As Capt. McMahan shoved the control
column forward in reponse to the too-steep climb, the plane's nose came down
slightly and, at least momentarily, the plane seemed to return to a normal
climb.
"After that," says Capt.
McMahan, "the first thing I did was to check the setting for the
stabilizer" (the two horizontal extensions on the tail, which control the
plane's pitch). "According to our control panel," he says, "the
stabilizer was set correctly." The captain retracted the landing gear,
switched off the landing lights and turned off the "no smoking" signs
in the passenger cabin.
At an altitude of 400 feet, however,
the plane began nosing up again, and the pilot began to use "electric
trim," another system for setting the stabilizer. That didn't work. He
tried "manual trim." That didn't work either. "There just wasn't
any response," he says. He tried both again, with no effect.
At 800 feet, with the plane climbing
into thick clouds, the captain asked Steve Heidt, the engineer, to check the
hydraulic system through which most of the controls work. "At this
time," the captain adds, "I wasn't too upset, as the £1011 has four
independent hydraulic systems - plenty of redundancy - and I was sure that one
of several possible procedures would fix our problem."
Capt. McMahan unlatched and reset
all switches associated with the plane's trim, or angle of flight. Will
Radford, the copilot, checked control-panel warning lights to make sure they
were working properly. Using control-panel devices, the engineer then
double-checked the hydraulic systems. By 3,000 feet altitude, all emergency
procedures concerning pitch and trim had been tried, and the crew couldn't find
out what was wrong.
Air-traffic control was notified of
the plane's plight by radio. Both the captain and the copilot got on the
controls, exerting full forward force on the control column. Even so, as the
plane climbed out over the Pacific Ocean, it pitched up more and more, far
above the normal 15 degrees.
"I recall observing 3,000 feet
. . . 3,500 feet . . . 4,500 feet on the altimeter," Capt McMahan says.
"Pitch attitude exceeding 18 degrees . . . 20 degrees . . . 22 degrees.
And the speed was decaying, 150 knots . . . 145 . . . 143 . . . 140."
In that sequence, the plane was fast
running into the danger of a fatal stall, because with the nose up and the air
speed dropping, the air wouldn't be moving across the wing fast enough to
provide sufficient lift. The solution for that problem is to get the nose down
and increase air speed - but the crew just couldn't get the nose down.
"Suddenly," Capt. McMahan
says, "I had the horrifying realization that we were going to lose it. I'm
trying to fly this thing as well as I can, and I thought, son of a bitch, I
can't even fly it - it won't respond. I had a very clear mental picture of
exactly what the aircraft was going to do - stall, roll to the left and descend
vertically, disappearing into the clouds - at night - into the water." A
week before, a Southern Airways DC9 had crashed, killing 68. And the week
before that the Pan Am and the KLM planes had collided on Tenerife.
"Accidents come in threes, they say, and I thought, 'My God, we're number
three.'"
AT THAT INSTANT, the captain yanked
all the throttles back, reducing power. For a pilot, it was an unnatural and
illogical move. Reducing power would cut air speed further, and that would seem
to increase risk of a stall. But, the captain says, "At the stage, you
quit being methodical - you just do something and do it fast."
The tactic worked. "I felt a
little change in control 'feel,' a little more control over the plane."
The captain then advanced the No. 2 throttle, which increased the thrust of the
No. 2 engine in the tail of the £1011. In the £1011, the two engines hanging on
the wings of the plane, Nos. 1 and 3, are canted slightly downward, and their
thrust makes the plane pitch up. But the No. 2 engine in the tail is canted
slightly upward, and its thrust makes the plane pitch slightly downward. The
increased thrust Capt. McMahan applied to the No. 2 engine did exactly that.
The nose slowly began to come down,
to about 18 degrees; speed began picking up, to about 150 knots, and at 9,000
feet the plane broke out of the overcast and into bright moonlight. "A
welcome change," the captain recalls. By adjusting the throttles slightly,
the captain was able to stabilize the plane at about 10,000 feet.
Jane Hooper, the flight-attendant
coordinator, had sensed something was wrong earlier and had been up to the
cockpit. But she had been told to go back and "strap herself in," the
engineer, Steve Heidt, says. "We were just too busy earlier," he
recalls. Miss Hooper came back again. She was told there was a control problem,
and she was asked to move all the passengers forward in the cabin to help get
the nose down. "It probably didn't help much, but in that situation we
figured every little bit would help," Heidt says.
Now, the question was, where to
land. The captain immediately ruled out returning to cloud-covered San Diego.
"No way was I going back into that weather." Palmdale Airport and
Edwards Air Force Base were considered, but they close at 10 p.m., and it was
after midnight. Phoenix and Las Vegas also were considered, but those choices
would mean flying over the Sierra Nevada, where turbulence could be fatal to a
plane already hard to control. That left Los Angeles International, and despite
cloudy conditions there, too. Los Angeles was chosen.
Which direction should the plane
come in from? At this point the cockpit voice recorder becomes available
(earlier sections had been automatically erased as the 30-minute tape is
continously reused) and the crew conversation indicates the captain was offered
the option of flying over Los Angeles itself into the airport.
"That's no good," the
captain said. ("I could imagine the holocuast if we went down over the
city," he recalls later. "I figured if we lose it, we should lose it
over water.")
So the Delta flight would come in
from the ocean. That had some disadvantages pilots dislike landing over water
at night, because there aren't any visual reference points. Among pilots, it's
called landing "over a black hole." But that approach also held
advantages: it made possible a long, straight-in approach. Pilots prefer that,
at it gives them plenty of time to stabilize the plane and handle any control problems.
And Jack McMahan was thoroughly familiar with that approach to Los Angeles
International.
A normal touchdown, however, would
be impossible. With no control over pitch so the pilot could force the nose
down on the runway, the plane might float across the airport on a cushion of
air and crash at the end. Even worse, as it neared touchdown, it might suddenly
pitch up a couple of hundred feet, stall, then crash down into the runway. With
no altitude to maneuver, there would be nothing the pilot could do.
The solution, Capt. McMahan figured,
was to come in with flaps on the wings set at a reduced angle. That would allow
the plane to come in at a higher speed - 170 knots instead of a normal 130 -
which was risky itself, but it would allow the pilot to "bang" the
plane down on the runway. "What we wanted was that positive ground
contact," Copilot Radford says. The final seconds would be the key.
THE APPROACH descent began, and the
Delta jet coasted down into the clouds hanging over Los Angeles. Crew members,
meanwhile, were still trying to solve their problem. "You've got the
stabilizer [indicator] showing full nose down . . . and you're not getting it .
. . I can't believe it," Heidt, the engineer, said, according to the tape.
The copilot radioed to the Los
Angeles tower to have fire trucks stand by. He also gave the number of
passengers so that enough ambulances could be called.
Then, at 2,500 feet, the landing
gear was extended, shifting the center of gravity, and the plane abruptly
pitched up again. "I shoved the control column full forward," the
captain says, "but we continued to climb while air speed deteriorated and
we were going above the landing glide slope. My first thought was: 'Since we
can't control the aircraft with the landing gear down, retract the gear, turn
south and ditch in the ocean parallel to the coast.'"
Instead, the captain again boosted
power on the No. 2 engine and cut thrust on No. 1 and No. 3. Slowly, slowly,
the nose began dropping.
Copilot Radford: "1,000 feet -
everything looking good - on glide path, on course."
At 500 feet, the Delta jet breaks
out of the clouds, and the runway is dead ahead.
Capt. McMahan: "I'm gonna touch
down and get on the brakes . . . right down the middle . . . and get it on . .
. Help me hold the controls . . ."
The plane slams onto the runway at
170 knots, and as Capt. McMahan applies brakes, the copilot calls out the
speed.
Copilot Radford: "130 . . . 120
. . . 110 . . . 100 . . . 90 . . . 80 . . . 70 knots, 60 knots, thank
God."
Engineer Heidt: "Wheeee-eh."
Tower: "Well, Delta 1080,
everything okay?"
Capt. McMahan: "Tell'em we're
all right - we'll take it to the gate."
Jane Hooper rushed into the cockpit
and kissed the pilot. "What was the problem?" she asked. Engineer
Heidt answered, "We had up, but no down; we just kept going up, and up and
up."
WHAT HAD GONE wrong? Within hours
Lockheed and FAA engineers were swarming over the plane. The stabilizer has, on
its trailing edges, small "elevators" that flip up and down in
conjunction with the movement of the stabilizer, and the engineers quickly
found the left elevator had stuck in the up position, causing the plane to
pitch up. (There isn't any warning light in the £1011 cockpit to indicate a
malfunctioning elevator, because the stabilizer is the main controlling device.
In the dark night, there wasn't any way to see the jammed elevator, even if the
problem had been suspected. Hence, there wasn't any way for the pilot to figure
out what what was wrong.)
Why had it stuck? Water from rain,
fog and mist had dripped down a structure in the tail onto a bearing. As the
plane had repeatedly ascended and descended during the many flights, changes in
pressure had sucked the water into the bearing. The bearing corroded and broke.
When Capt. McMahan maneuvered his flight controls just before takeoff, the
elevator, linked to the broken bearing, jammed.
Within hours, Lockheed had
telephoned airlines all over the world using the £1011, warning them to check
the bearing. (Several were found full of water and beginning to corrode.)
Within days, the FAA issued an emergency airworthiness directive making the
check mandatory in the United States. On June 5, 1977, even after making the
check, a British Airways £1011 experienced a similar, though less severe,
control problem. Taking off from Ailcante, Spain, the British plane, loaded
with 160 passengers and headed for London, managed to divert to Barcelona and
land safely. The FAA then ordered a visual check of the elevator before each
£1011 takeoff. Lockheed has since devised a deflector to drain water away from
the bearing, along with a seal on the bearing to keep water out and grease in,
and it has rebuilt the bearing itself so that if any part fails, the other
parts will function.
As for Delta's crew and passengers,
they switched to another Delta plane and took off for Dallas, the next stop for
Flight 1080. On the way to Dallas, Capt. McMahan got a note from a passenger
saying, "All that screwing arounds in L.A. is going to make me late for a
connection - what are you going to do about it?" The best he could, was
the reply.
Late last year, Capt. McMahan won
the FAA's prestigious Distinguished Service Award for bringing Flight 1080 in
safely. Will Radford and Steve Heidt received FAA certificates of commendation.
No comments:
Post a Comment