It was just
after 6:00pm on the evening of February
2nd, 1991 and USAir flight 1493 was
preparing to land at Los Angeles
International. Six crew members and 83
passengers were aboard the 737 during its
three hour flight from Columbus, Ohio. On
the ground, Skywest's flight 5569 was
preparing for takeoff. The Metroliner
carrying 10 passengers and two crew was
bound for Palmdale, one of the many rush
hour commuter flights out of the LA area.
USAir 1493 cleared for
the ILS 24L approach as Skywest 5569 was
taxing away from the gate towards runway
24L. Due to traffic, Skywest 5569 was
cleared to taxi to 24L and enter at the
intersection of taxiway 45, some 2,200ft
from the runway threshold. As the Skywest
Metro awaited it takeoff clearance, USAir
1493 touched down near the threshold of
runway 24L and shortly thereafter slammed
into 5569. Both aircraft skidded down the
runway, the Metro crushed beneath the
737's fuselage. The wreckage came to rest
on the far side of the taxiway against an
empty building. All 12 in the Skywest
aircraft were killed as were 21 people in
the USAir 737, including the captain.
......Clearly both aircraft believed they
had sole use of the runway at the time of
the crash. In order to determine the the
origin of the confusion, a careful
analysis of radio transcripts and ATC
procedures at Los Angeles International
was begun. After receiving clearance from
Clearance Delivery, the flight strips go
directly to the local controller LC),
bypassing the ground controller (GC).
While this lessened the GC's workload by
not having to mark the flight strips, it
actually increased the LC's workload by
denying them information regarding the
aircraft's position on the field. Aircraft
were allowed to request intersection
departures directly from the GCs. Because
Skywest 5569 was taxing from the south
side of the airport, it had been in
contact with both GC1 and GC2 on its way
to runway 24L and had been cleared to hold
short at taxiway 45 before contacting LC2.
It's initial call to LC2, it reported "at
[taxiway] 45 we'd like to go from here if
we can." After the accident, LC2 reported
that she had not heard the "at [taxiway]
45" part of the transmission. Because the
flight strips bypassed the GCs, there was
no indication for LC2 as to the aircraft's
position. LC2 then cleared 5569 to taxi up
to and hold short of runway 24L which was
acknowledged. During this time, another
flight, Wings West 5006, had just landed
and was attempting to clear the runway.
The crew had inadvertently changed
frequencies and was out of contact with
LC2. Skywest 5569 was cleared into
position and hold on runway 24L.
Communications with
Wings West 5006 was re-established just
after this instruction and several seconds
were spent with unnecessary transmissions
regarding the loss of communication.
Southwest 725 was also preparing for
takeoff at the time and LC2 also cleared
it to taxi up to and hold short of runway
24L. Just after this, USAir 1493 called
for the left side. LC2 confirmed that
Southwest 725 was holding short and then
cleared 1493 to land. Shortly thereafter,
Wings West 5072 called ready for
departure. There was no flight strip in
front of LC2 for 5072, so she and several
others began a search for it. It was found
still at the Clearance Delivery station,
believed to still be waiting for initial
contact. Just after the strip was found,
LC2 saw 1493 touchdown and cleared 725 to
taxi into position and hold. Just seconds
after this transmission, 1493 collided
with 5569 still sitting in position and
hold at intersection 45 on 24L.
......The First Officer of 1493 reported
that the touchdown was normal. As the nose
was being lowered, he reported that the
landing lights began to reflect on 5569's
propellers and its rear position light
became visible. Maximum braking was
applied, but there was insufficient space
and time to avoid the collision. He did
not report hearing that another aircraft
had been placed in position and hold even
though 1493 had come on to LC2's frequency
prior to the instructions. LC2 was clearly
distracted by several events in the few
short minutes prior to the accident.
Allowing 5569 to make an intersection
departure was acceptable and she cleared
the flight into position and hold prior to
giving 1493 landing clearance.
Initial confusion with 5006 caused her to
lose awareness of 5569's position. The
further confusion regarding the flight
strip of 5072 caused her again to avert
her attention from the situation on the
active runways. She later said she had
believed 5072 taxiing in front of the
tower to runway 24L was actually 5569 and
formed a mental picture that all was
correct. The NTSB cited many factors as
contributing to the cause of the accident.
Primary was ATC procedures at LAX. The FAA
later required LAX to revise its flight
strip handling to relieve the LCs from
carrying the full responsibility of flight
strip marking and handling and allowing
better awareness during high workloads.
LC2 was also cited for becoming distracted
and allowing a breakdown in awareness
during the incident period.
The NTSB also cited
lighting placement on the Metro, showing
that its light blended with and were not
conspicuous against the runway environment
background during low light periods.
Although both flight crews were operating
within their ATC clearances, they were
both still responsible for "see and avoid"
operations since conditions were VFR.
......On a personal note, I was acquainted
with one of the individuals on board
Skywest 5569. This and the fact that I am
from the LA area and have been in and out
of the airport many times brought this
accident to the forefront of my attention.
I have been given "position and hold"
clearances on several occasions with
another aircraft on approach. I used to
accept them and sit with my back to the
other aircraft, hoping that I would be
cleared for takeoff before the other
aircraft made it to the runway.
After researching this
accident further, I no longer accept them
unless I hear a clearly understood
transmission from both the tower and the
other aircraft. Due to the high volume of
training at my local airport, the tower
will always advise traffic on final of any
attempts to release another aircraft prior
to its arrival. It will also advise the
traffic on the ground of the approaching
aircraft's position in relation to
touchdown. Remember, as PIC, you are
responsible for your aircraft's safety and
you do not have to accept an instruction
you do not feel comfortable with. Be
pro-active in both your flight and ground
operations and don't assume that everyone
else knows of your position.