Aviators around the world have been arguing for months about whether
the
pilots of Swissair Flight 111 should have flown by the book or
by instinct.
Now a summary of the cockpit voice recording shows that the flight's
two
pilots were sharply at odds over that very issue. The co-pilot
wanted to scrap
the rules and land quickly. The captain insisted they stick with
convention.
The issue is important. Critics argue that a prompt landing could
have saved
the jet, while Swissair officials have contended that such a touchdown
wasn't possible.
As smoke seeped into the cockpit of the MD-11 the night of Sept.
2, the pilots
could have headed straight for the Halifax, Nova Scotia, airport
rather than
follow a lengthy checklist and plan other time-consuming procedures,
such as
dumping fuel. While the cockpit-recording summary doesn't provide
any evidence
of an acrimonious argument, it does show the Swissair co-pilot
repeatedly
suggesting steps aimed at a quick landing, and the captain rejecting
or ignoring those proposals.
The co-pilot wanted a rapid descent. He suggested dumping fuel
early so the
jet wouldn't be too heavy to land. And he talked of heading directly
to the
airport rather than turning out to sea to dump fuel.
But the Swissair captain told the co-pilot, who was flying the
plane, not to
descend too fast. The captain delayed a decision on dumping fuel.
On the issue
of heading for the airport or turning toward the sea, the captain,
apparently
preoccupied with the checklist, didn't give any definitive answer.
At another point, the captain brushed off a proposal by the co-pilot.
"The
captain said, in effect, 'Don't bother me,
I'm going through the checklist,' "
one person familiar with the cockpit-recording summary said.
Minutes later, the jet plunged into the Atlantic Ocean, killing
all 229 on
board. The Canadian government is investigating the crash.
Differences between the captain and his co-pilot during the final
minutes of
the flight haven't been revealed before because, under Canadian
law, the
cockpit voice recording can't be released publicly. But a preliminary
summary
of the recording, prepared by Canadian government investigators,
was obtained
by The Wall Street Journal. The summary reveals the rare drama
of two pilots
battling to save the plane -- and their own lives -- while at odds
over how to do it.
David Austin, a spokesman for the Transportation Safety Board of
Canada, said
he couldn't comment because he was prevented by Canadian law from
discussing
the contents of the cockpit voice recording. Swissair also declined
to
comment, saying the voice recording is confidential.
The captain of Flight 111 from New York to Geneva was 49-year-old
Urs
Zimmermann. He was a veteran Swissair pilot, although he had been
flying the
MD-11 for just over a year. The co-pilot was Stefan Lowe, 36, who
had flown
for Swissair since 1990 but had been co-piloting the aircraft for
just four
months. Conversations between the two, mostly in Swiss German,
were described
in English in the summary.
The flight began smoothly enough. After the jet took off and climbed
to 33,000
feet, the cockpit recording picked up the sounds of cutlery and
a conversation
about food. The pilots were eating dinner.
But at 10:11 p.m. local time, there was a strange smell. At first
the pilots
seemed confused about its nature, but within two minutes Capt.
Zimmermann said
he could "definitely" smell smoke, according to the summary.
Though
investigators are checking cockpit wiring, the cause of the smoke
is still unknown.
The pilots discussed turning back to Boston, New York or Bangor,
Maine. But
when Co-pilot Lowe radioed the "PAN, PAN, PAN" distress
call to a Canadian
air-traffic controller, the controller suggested Halifax, nearly
dead ahead, only 70 miles away.
At 10:16 p.m., Co-pilot Lowe, who was flying the jet through its
autopilot,
turned toward Halifax. Just 14 minutes remained before the crash.
"Swissair One Eleven, you're cleared to ten thousand feet
... ," the Canadian
controller radioed. But when the co-pilot told Capt. Zimmermann
the jet would
descend to 10,000, the captain ordered him "not to go too
fast," the summary
says, apparently meaning "don't descend too fast."
The Swissair pilots, meanwhile, had donned their oxygen masks.
Because
microphones in the masks picked up their breathing, respiration
rates could be
measured. Capt. Zimmermann's had soared to nearly 25 breaths per
minute,
indicating high stress. Co-pilot Lowe's was a more moderate 11
breaths per minute.
There were reasons for stress, beyond the central one. The pilots
didn't have
landing charts for Halifax at hand, so they had to ask a flight
attendant to
bring them forward. The chief flight attendant had to be informed
about the
diversion to Halifax; he announced it to passengers in three languages.
And
the pilots had to make more radio calls to the controller.
At 10:20 p.m., the controller radioed, "You've got thirty
miles to fly to the
threshold" of the Halifax runway. By this time, Co-pilot Lowe,
who may have
been heeding Capt. Zimmermann's admonition, had slowed the jet's
rate of
descent to 3,100 feet per minute from 4,000 feet per minute.
The co-pilot was clearly worried about that. According to the summary,
he told
the captain he wanted to descend "as fast as possible"
so they could land if
the smoke got too dense. The jet was now at 19,800 feet.
Co-pilot Lowe also asked the captain about dumping fuel. The two
talked about
whether to dump immediately or to wait awhile. Capt. Zimmermann,
the summary
says, put off making the decision.
The air controller, meanwhile, had guided the jet due north, pointing
it
slightly to the left of the airport so the plane could cut enough
altitude to
make a direct approach to Halifax runway 06.
At 10:22 p.m., the crew had to make a crucial decision. Swissair
officials
contend the jet was too high and heavy with fuel to make a direct
approach to
runway 06. The jet was 25 miles from the airport and, at 11,900
feet, still
too high for a normal approach. But a number of pilots have said
it was low
enough for a steeper, emergency approach. Should the jet turn right
toward the
airport or circle left, back out to sea?
As for dumping fuel, in the five minutes or so it would take to
fly directly
to the airport, the MD-11 could have cut its weight to its maximum
overweight-
landing limit of 218,000 metric tons from 230,000 tons. But jettisoned
fuel
might have spattered people and property below.
"Are you able to take a turn back to the south, or do you
want to stay closer
to the airport?" the controller asked. Co-pilot Lowe asked
the captain whether
to turn south for dumping or land the plane. But Capt. Zimmermann,
the
cockpit-recording summary says, didn't give any definite answer.
"OK, we are able for a left or a right turn toward the south
to dump," Co-
pilot Lowe radioed the controller. As he began circling left to
head out to
sea, however, he apparently was worried that the jet would get
too far from
the airport. He would reduce speed if the captain agreed, he told
Capt. Zimmermann.
The captain, according to the summary, replied
that he was in the midst of a
checklist and "didn't want to be interrupted"
so often. Do what was
appropriate, he told the co-pilot.
A minute later, at 10:23 p.m., the jet's autopilot stopped functioning
and Co-
pilot Lowe radioed that he had to fly the plane manually. Then,in
overlapping
transmissions, both Capt. Zimmermann and Co-pilot Lowe radioed
that the jet
was declaring a full-blown emergency, with the co-pilot adding,
"We have to
land immediate."
At this point, the summary says, respiration rates of the captain
and co-pilot
were both at 25 breaths per minute, showing both under high stress.
The
summary adds that their words became rushed, their voices urgent.
At 10:25 p.m., perhaps because of the thickening smoke, Co-pilot
Lowe told the
captain it was all he could do just to fly the plane. Seconds later,
his
instruments -- bright video displays -- went dark, and he spoke
of flying on a
few standby instruments.
The cockpit voice recording stopped. Five minutes later, Swissair
111 went down.
