Story written by Airmanshiponline.com
Frustration, fog and fire - how a terrorist bomb
blast 100 kilometers away led to the greatest disaster in aviation
history, taking the lives of 583 innocent people.
Spain's Canary Islands - Ilas Canarias - an archipelago of seven
major volcanic outcrops between 57 and 250 nautical miles out into
the Atlantic Ocean from the Moroccan coast of northwest Africa, have
long been a tourist destination rivalling the balmy resorts of the
Mediterranean. Even ancient Greek and Roman seafarers knew them as
"the Fortunate Isles".
latitude 28 degrees north, their warm and sunny climate is the envy
of Northern Europeans, and for many years the group's two principal
cities of Las Palmas on Grand Canary and Santa Cruz on Tenerife were
regular ports of call for ocean liners en route to South America and
As air travel
gradually replaced sea transport in the postwar years, major
airports were developed to serve Las Palmas and Santa Cruz to cope
with the islands' booming tourist trade. New hotels, catering
particularly for Scandinavians, Dutch and Germans, proliferated
throughout the islands, with Las Palmas, as the Canary Islands'
capital, becoming the principal international airport for the group.
Strenuous efforts were also made to attract American tourists, the
islands' seaports becoming the starting point for luxury cruises of
Sunday March 27,
1977 should have been no different to any other spring day at Las
Palmas Airport, with the usual frequent international flights coming
and going from all over Europe and from the other side of the
But at 1.15pm that
afternoon, the bustling life of the airport passenger terminal was
thrown into panic and confusion when a small bomb planted by a
terrorist exploded in a florist's shop on the terminal concourse.
Airport authorities had been warned of the blast 15 minutes before,
so although the bomb caused a good deal of damage inside the
terminal building, it was being evacuated at the time and there were
no fatalities. However, eight people were injured, one seriously.
Spanish airport administration afterwards, a spokesman for a
militant Canary Islands independence movement, speaking from Algeria
in North Africa, claimed responsibility for the explosion and hinted
that a second bomb was planted somewhere in the terminal building.
Unable to tell
whether or not this further threat would eventuate, the local police
had no alternative but to instruct the civil aviation authorities at
Las Palmas to close the airport pending a thorough Search for the
second bomb. Their decision inevitably affected far more than
airport personnel and waiting passengers: numerous international
flights, inbound to Las Palmas from a variety of departure points,
were approaching the Canary Islands at the time, some of them within
less than an hour's flying time from Las Palmas.
The difficulty was
overcome by diverting all inbound Las Palmas traffic to Los Rodeos,
the other Canary Islands international airport, serving Santa Cruz
on the island of Tenerife, some 50 nautical miles to the northwest
(a destination that most, if not all the international flights would
be "carrying as an alternate" for Las Palmas in any case).
The only real
problem would be one of logistics - the additional traffic would
sorely try Los Rodeos airport's capacity for a few hours. The second
airport possessed only a single runway, and even its aircraft
parking areas had nowhere near the capacity to handle double its
normal daily aircraft movements. Even so, it was the only possible
option in the circumstances and it was expected that Las Palmas
would not be closed for long.
Among the numerous
flights from European ports diverted to Los Rodeos was a charter
trip flown by KLM's Boeing 747 PH-BUF Operated by KLM as Flight
KL4805 on behalf of the Holland International Travel Group, it had
departed Amsterdam's Schiphol Airport that morning at 9.31am local
time carrying 234 mostly young passengers escaping the Northern
European cold for a holiday in the sunny warmth of the Canaries.
They included three babies and 48 children. Most were Dutch, but
amongst them were two Australians, four Germans and four Americans.
During the flight,
many of the passengers were intrigued to find that their pilot in
command was the handsome and esteemed Jacob Veldhuyzen van Zanten,
KLM's chief training captain for Boeing 747 aircraft, featured in
company advertisements and in the current issue of the company's
in-flight magazine placed in the back pockets of all the cabin
Captain van Zanten
had been flying since 1947 and had been an airline pilot with KLM
since 1951 when, as a 24-year-old, he commenced duty as a first
officer on DC-3s. He now had nearly 12,000 hours' experience, more
than 1500 hours of this time as captain of Boeing 747s. But these
days he spent most of his working hours instructing in KLM's
After its four hour
trip from Amsterdam across Belgium, France and Spain, then southwest
out over the Atlantic to Tenerife, PH-BUF touched down on Los Rodeos
Airport's 3400 meters Runway 30 at 1340 hours GMT (1.10pm local
For once the fabled
Canary Islands failed to live up to their reputation for fine
weather: those on board the KLM Boeing 747 were greeted with the
sight of patchy low cloud, light rain, and areas of fog in the
distance. The light wind was from the northwest.
The apron area,
together with a portion of the main taxiway paralleling the runway,
was already fully occupied by diverted aircraft when the KLM 747
arrived at Los Rodeos. The tower controller therefore directed the
Dutch crew to vacate the runway via the last intersecting taxiway,
continue towards the holding point for the reciprocal Runway 12, and
to park the aircraft on the holding area apron next to a Norwegian
Boeing 737. A short time afterwards a Danish Boeing 727 and then a
SATA DC-8 also landed at Los Rodeos and were directed to park in the
van Zanten, not knowing how long the reopening of Las Palmas Airport
on Grand Canary was likely to be delayed, but conscious of his need
to complete the flight there as soon as possible, had instructed his
passengers to remain on board PH-BUF. After about 20 minutes however
he relented, and they were transported to the airport terminal by
At 1.45pm local time
(a little more than half an hour after PH-BUFs arrival), while the
Dutch crew were still on the flightdeck discussing how the delay was
likely to affect their stringent company duty time limitations, a
Pan American Boeing 747, N736PA, landed and taxied to the same
holding area, parking directly behind the KLM Boeing 747. Flying in
across the Atlantic from John F Kennedy Airport in New York, it too
had been diverted to Tenerife from its original destination of Las
The PanAm service,
designated Flight PA1736, had originated in Los Angeles, where 364
passengers - most of them retirees over 55 years of age - had
boarded Clipper Victor for the first stage of a charter flight to
Grand Canary. Here they were to join the Royal Cruise Line's ship
Golden Odyssey for a 12 day "Mediterranean Highlights" cruise.
Departing Los Angeles late the previous afternoon, they had flown
direct to New York, landing at John F Kennedy Airport just under
five hours later. The Boeing 747 was refueled, 14 more passengers
came aboard, and there was a change of crew.
After an hour and a
half on the ground, the flight took off again for Las Palmas.
Canary Islands six hours later, the PanAm flight crew were informed
by Air Traffic Control that Las Palmas Airport on Grand Canary was
temporarily closed and that their aircraft was to be diverted to Los
Rodeos Airport on Tenerife.
For the crew, this
was unwelcome news. Already they had been on duty for the best part
of eight hours and the diversion would inevitably add several more
hours to the trip and
there were the
passengers themselves to consider. It was now nearly 13 hours since
most of them had boarded the aircraft at Los Angeles. As well as
this, they had experienced an hour and a half's unexpected delay at
Los Angeles Airport before their departure late the previous
afternoon. They were very tired and the majority of them were no
The PanAm flight's
Captain Victor Grubbs, a 57 year old veteran American pilot of
21,000 hours' experience, sensing from the Spanish air traffic
controller's instructions that Las Palmas was expected to reopen
before long, therefore asked if, instead of diverting into Los
Rodeos, the PanAm flight could continue to Las Palmas and be cleared
to join a holding pattern to await the reopening of the airport.
N736PA was carrying more than adequate reserve fuel and holding in
this way would give them quicker and easier access to a landing at
Las Palmas than having to make a further flight from Los Rodeos,
with all that entailed in terms of procedures and clearances.
disappointment of the seasoned American flight crew - Grubbs, First
Officer Robert Bragg, and Flight Engineer George Warns - ATC refused
the request, so there was nothing for it but to join the numerous
other airline aircraft waiting on the ground at Los Rodeos.
Captain van Zanten's initial decision of half an hour earlier, after
landing and parking on Los Rodeos' Runway 12 holding apron as
directed behind the KLM Boeing 747 PH-BUF, Captain Grubbs announced
that the passengers should remain on board in anticipation of an
early clearance on to Las Palmas. But the main cabin doors were
opened, some passengers taking advantage of this to breathe the
fresh Canary Islands air and to take photographs of what they could
see from the aircraft.
Meanwhile, on the
flight deck of PH-BUF, Captain van Zanten was becoming increasingly
concerned that he and his crew were running out of time as far as
their permitted period of duty was concerned. Until a few years
previously, a KLM aircraft captain was authorized to exercise his
discretion in extending his crew's duty time to meet unforeseen
delays and so complete a flight satisfactorily. But because of a
number of instances in which serious crew fatigue had jeopardized
safety, this provision had been revoked.
Instead, the Dutch
civil aviation authority now insisted that flight crew duty times be
rigidly observed, even at the cost of having to delay the completion
of a flight. Captains who exceeded the limitations were liable to
To add to the
difficulty, recent changes to the Dutch aviation legislation had
made the calculation of precise duty time limitations a complex
matter involving a number of different factors, and KLM had
instructed crews that the company should be contacted for a ruling
if they were in any doubt. Aware that if the reopening of Las Palmas
Airport was delayed too long, he would be compelled to remain
overnight at Los Rodeos, with all the burden that would involve in
arranging appropriate accommodation at short notice for his
passengers and crew, Captain van Zanten decided to contact the KLM
operations office in Amsterdam by H/F radio while they were waiting.
The captain spoke to the duty operations officer himself, outlined
the difficulty in which they were placed, and asked for the precise
duty time available to them without any infringement of limitations.
KLM Amsterdam's advice when it came back to PH-BUF by radio was
something of a relief - the crew had until 1800 hours GMT (6.30pm
Los Rodeos Tower called all waiting aircraft on the ground control
frequency to advise that Las Palmas Airport was now open again.
Despite a rigorous Search, no second bomb could be found, and the
police concluded that the warning had been a hoax.
In the Los Rodeos
Airport terminal, passengers who had left their various aircraft
were called over the PA system to begin boarding again via the
airport buses provided. All the passengers from the KLM aircraft did
so except a travel guide for the Holland International Travel Group,
Miss Robina van Lanschot. Having attended to the needs of her
charges on the flight from Amsterdam, she decided to stay overnight
at Santa Cruz. Her spur of the moment decision was to save her life.
Meanwhile, out at
the holding area apron for Runway 12, Captain van Zanten, his
anxiety over flight time limitations now relieved by the advice from
his company, decided he would refuel for the return flight to
Amsterdam before taking off for Las Palmas. There was time to do so
now, whereas at Las Palmas, with the number of aircraft that would
be descending on it, there might be delays in obtaining fuel. The
Dutch crew accordingly ordered fuel to be brought out to the KLM
Boeing 747 in tankers - a decision that was in hindsight to seal the
fate of both 747s that day at Tenerife.
A short time later,
the three smaller airliners parked by the two Boeing 747s - the
Boeing 737, DC-8 and Boeing 727 - started their engines and were
cleared to taxi for takeoff, the duty runway still being Runway 30.
First maneuvering carefully around the massive KLM and PanAm.
aircraft to reach the Runway 12 entrance, they then backtracked on
the runway until they had bypassed the center portion of the
parallel taxiway that was still congested by parked aircraft. At
this point they rejoined the main taxiway to continue to the holding
point for Runway 30.
Although the weather
was showing signs of further deterioration and light rain was still
falling intermittently, surface visibility remained satisfactory at
about 10 kilometers.
Now it was the PanAm
Boeing 747s turn to depart. Aboard N736PA, Captain Grubbs'
announcement to his passengers that Las Palmas was finally open for
traffic again was greeted with general applause in the cabin - at
last they could look forward to joining their cruise ship and
getting their heads down for the night, a prospect that seemed
almost too good to be true after the best part of 24 wakeful hours
since most of them got out of bed at home in California. For the
flight on to Las Palmas, N736PA would have two additional passengers
- two company staff members had boarded the flight to take advantage
of a free ride over to Grand Canary.
But when First
Officer Bragg called the tower to request a clearance to start the
engines, the ground controller replied that while there was no delay
as far as ATC clearances were concerned, the PanAm Boeing 747 could
have problems in departing at the moment because the main taxiway
was still congested with other parked aircraft. The only way to the
holding point for Runway 30 was the route the other aircraft had
followed - via the Runway 12 entrance, then backtracking on the
runway itself. But KLM's PH-BUF, which was only now beginning to
refuel, blocked that way for its PanAm sister ship.
somehow contained his frustration. He hadn't wanted to land at Los
Rodeos anyway, and if ATC had allowed them to hold in the air as
he'd requested, they could be making their approach to Las Palmas by
now. To clarify their situation, First Officer Bragg now called the
KLM crew on the ground control frequency. "How long will it take you
to refuel?" he asked.
"About 35 minutes,"
he was told with no hint of an apology.
The PanAm crew's
only possible alternative was to taxi around the Dutch Boeing 747 as
the other three aircraft had done. But this looked doubtful. Los
Rodeos Airport had not been designed to handle aircraft as big as
the Boeing 747 and the width of the holding area apron did not leave
a great deal to spare. Undaunted, First Officer Bragg and Flight
Engineer Warns climbed down to the ground to pace out the amount of
clearance available. It was insufficient - there was no way N736PA
could gain access to the runway until PH-BUF moved out of their way.
Bragg and Warns
returned to the flightdeck to convey the unwelcome news to Captain
Grubbs - there was nothing they could do but await the pleasure of
the Dutch crew.
While the American
crew inwardly fumed at this further frustration, the local weather
continued to deteriorate. Patches of fog, visible in the distance
when they arrived at Los Rodeos, were now blowing in onto the
runway. And the low cloud and light rain persisted. Already the
surface visibility, which had been some 10 kilometers, was reducing
intermittently to between one and a half and three kilometers.
refueling of PH-BUF was completed. The tanker vehicles drove away,
the doors of the aircraft were closed, and the engines were started.
But by the time the Dutch crew called the tower on the ground
control frequency of 118.7mhz at 1656 hours GMT (4.26pm local time)
for permission to start engines, the patchy fog had moved in across
the airport to completely obscure the runway, reducing visibility in
some places to as little as 300 meters, though this was fluctuating.
approval was given and shortly afterwards the KLM aircraft was
cleared to taxi to the holding point for Runway 12 and instructed to
switch to the aerodrome control frequency of 119.7. Two minutes
later at 1658 hours, while standing at the holding point for Runway
12, the KLM aircraft called the Tower on the aerodrome control
frequency to request a clearance to enter the runway and backtrack
to the beginning of Runway 30 for takeoff.
exchanged in English between the Dutch Boeing 747 and the Spanish
tower controller went as follows:
KLM: "We require
backtrack on Runway 12 for takeoff on Runway 30."
Tower: "Taxi to the
holding position for Runway 30 ... taxi into the runway ... leave
the runway third to your left."
KLM: "Roger, Sir.
Entering the runway at this time ... and we go off the runway again
for the beginning of Runway 30."
... taxi straight ahead ... ah ... for the runway ... make ... ah
KLM: "Roger, make a
backtrack ... KL 4805 is now on the runway."
KLM (half a minute
later): "You want us to turn left at Taxiway 1?"
negative ... taxi straight ahead ... ah ... up to the end of the
runway ... make backtrack."
KLM: "OK, Sir."
Meanwhile, the PanAm
crew, having also sought a clearance to start engines and to taxi,
were about to move their Boeing 747 on to the runway at the holding
point for Runway 12. At this stage, the visibility on the airfield
had deteriorated in the fog conditions to the extent that the tower
controllers could see neither the runway itself nor the two taxiing
Boeing 747s. The PanAm crew therefore sought confirmation that they
were to enter the runway while the KLM aircraft was still using it.
At 1702 hours GMT, First Officer Bragg, after switching to the
aerodrome control frequency of 119.7, called the tower controller:
PanAm: "Ah ... we
were instructed to contact you and also to taxi down the runway ...
is that correct?"
... taxi into the runway and ... ah ... leave the runway third ...
third to your left."
PanAm: "Third to the
left ... OK."
Tower: "Third one to
Spanish controller's English pronunciation was not entirely clear to
the American crew, for Captain Grubbs remarked to First Officer
Bragg: "I think he said first." Bragg replied: "I'll ask him again."
Both Boeing 747s
were now communicating with the Tower on the same frequency and,
before Bragg contacted the controller again, the American crew heard
him call the KLM aircraft:
Tower: "KL 4805 ...
how many taxiway ... ah ... did you pass?"
KLM: "I think we
just passed Taxiway 4 now.
Tower: "OK ... at
the end of the runway make one eighty and report ... ah ... ready
for ATC clearance."
Taxiing in the fog
some distance behind the KLM aircraft, the American crew were having
some difficulty in clarifying the controller's instruction in their
minds. Bragg was studying a small diagram of Los Rodeos Airport
which he had opened in the flip chart on his knee.
"This first [intersecting
taxiway] is a 90 degree turn." he explained to Captain Grubbs.
Grubbs: "Yeah - OK."
Bragg: "Must be the
third [the controller meant] ... I'll ask him again."
Grubbs: "We could
probably go in, it's ... ah ...
"You've got to make a 90 degree turn!"
(uncertainly) "Yeah ...
degree turn to get around ... this one further down here is a 45."
Bragg pressed his
microphone button and called the Tower: "Would - you confirm that
you want us to turn left at the third intersection?"
Tower: "The third
one, Sir ... one two three ... third one."
Warns interposed light heartedly to the other crew members: "We'll
make it yet."
As the PanAm crew
began to go through their pre-takeoff checks, the tower controller
further instructed them to report leaving the runway, and Bragg
acknowledged the call. But they were still having difficulty sorting
out which taxiway the controller wanted them to use.
"Haven't seen any
yet," Grubbs remarked to Bragg as they continued rolling down the
runway. "I haven't either," Bragg replied. Then, five seconds later,
he exclaimed, "There's one!"
"That's the 90
degree," said Grubbs, as they continued past it. Their pre-takeoff
checks were almost complete when they heard the KLM Boeing ask the
tower controller if the runway centerline lights could be switched
on - the KLM crew needed to know if they were available to assess if
visibility met their minimum takeoff conditions.
having checked, replied that the runway centerline lights were out
of service. He also passed this information to the PanAm crew. Even
so, both crews were evidently satisfied that runway visibility was
sufficient for takeoff.
The PanAm crew then
sighted the second taxiway through the fog. "That's two!" the
Warns: "Yeah ...
that's the 45 [degrees] there."
Bragg: "That's this
one right here."
Grubbs: "Yeah ... I
Warns: "Next one is
almost a 45..."
Grubbs: "But it does
... it goes ... ahead. I think it's gonna put us on the taxiway."
"Maybe he counts
these as three," Bragg said as the PanAm Boeing 747 continued
rolling down the runway past the connecting taxiway intersection.
Aboard the KLM
Boeing, which had now reached the end of the runway, Captain van
Zanten was at this moment maneuvering his huge aircraft round
through 180 degrees to face the direction of takeoff. Just after
1705 hours, as First Officer Klass Meurs finished the pre-takeoff
check list, van Zanten opened the throttles slightly and the
aircraft began to inch forward. Meurs checked him: "Wait a minute we
don't have an ATC clearance.
Van Zanten held the
aircraft on the brakes: "No ... I know that. Go ahead and ask."
Meurs called the
Tower as the controller instructed: "KL 4805 is now ready for
takeoff ... we're waiting for our ATC clearance."
Tower: "KL 4805 ...
you are cleared to the Papa beacon ... climb to and maintain Flight
Level 90 ... right turn after takeoff ... proceed with heading 040
until intercepting the 325 radial from Las Palmas VOR."
As Meurs began to
read back the clearance to the tower controller, van Zanten released
the KLM Boeing's brakes and began advancing the throttles to takeoff
power. "Let's go," he called to Flight Engineer Willem Schreuder,
First Officer Meurs,
still transmitting to the Tower, continued: "Roger, sir, we are
cleared to the Papa beacon, Flight Level 90 until intercepting the
325." By this time the KLM aircraft was six seconds into its takeoff
run, so he added: "We are now at takeoff."
the KLM transmission to mean that the Boeing 747 was ready for
takeoff): "OK ... standby for takeoff ... I will call you."
beginning of this exchange between the KLM aircraft and the Tower,
the PanAm crew were understandably alarmed: "We are still taxiing
down the runway!" Bragg transmitted urgently.
PanAm, 1736, report the runway clear."
PanAm: "OK ... will
report when we are clear."
Tower: "Thank you"
protesting transmission conflicted with the controller's instruction
to KLM. Instead of the words "standby for takeoff ... I will call
you," all the KLM crew heard after the controller's first "OK" was a
squeal resulting from the two simultaneous transmissions on the same
The exchange that
followed between the Tower and the PanAm 747 was however audible on
the KLM flightdeck. But by this time the KLM Boeing was 20 seconds
into its takeoff run. With Captain van Zanten and First Officer
Meurs both concentrating fully on the takeoff itself, only Flight
Engineer Schreuder took in the possible significance of the two
transmissions. "Did he not clear the runway then?" he asked the
The captain, giving
all his attention to the takeoff, did not take in the engineer's
question either. "What did you say?" he asked over his shoulder.
"Did he not clear
the runway - that Pan American?" Schreuder repeated.
"Yes, he did," both
pilots answered emphatically.
The KLM takeoff
At this stage, the
PanAm Boeing, its crew having missed the intersection for Taxiway 3
which the Tower had directed them to take, and unaware of what the
other 747 was doing, was still on the runway, approaching Taxiway 4.
still uneasy about occupying the runway in such poor visibility with
the KLM aircraft's takeoff obviously imminent, was keen to be out of
its way as soon as possible.
"Let's get the hell
right out of here," he remarked to his crew:
"Yeah ... he's
anxious, isn't he?" Bragg agreed.
"After he's held us
up for all this time," enjoined Warns, "Now he's in a rush."
A few seconds later,
the PanAm crew caught sight of lights that were materializing
through the fog directly ahead. Hazy at first, they seemed for a
long moment to be stationary. But as they continued to brighten, it
quickly became obvious they were approaching fast!
through the windscreen in stunned disbelief. "There he is ... look
at him!" he cried out. "... ... that son-of-a-bitch is coming!"
Desperately pushing all four throttles wide open, he attempted to
swing the Boeing 747 off the runway to the left.
"Get off! Get off!
Get off!" Bragg yelled frantically as he saw the other aircraft's
nose begin to rise into the takeoff attitude.
Aboard the hurtling
Dutch aircraft, First Officer Meurs' eyes were fixed on his steadily
rising airspeed indicator. "V1" he finally called.
At the same moment,
van Zanten sighted the PanAm 747 slewing, across the runway ahead of
them. Instinctively - there was no hope of stopping - he hauled back
on the control column to try and lift over the American. But too
suddenly the tail bumper struck the runway, emitting a shower of
But lift the KLM
aircraft did - just before reaching the other - only it was too
late. Its nose leg cleared the PanAm fuselage, but at 140 knots the
main undercarriage slammed into it, slicing off the fuselage top as
the No 4 engine demolished the hump just behind the flight deck, and
both aircraft exploded into flames.
For a few seconds
more the burning Dutch aircraft remained in the air, then fell back
on to the runway, slewing through 90 degrees before coming to rest
with its engines torn off, 150 meters further along the runway. None
of the fuselage doors were opened before its fuel tanks exploded,
enveloping the entire aircraft in a raging fire.
Aboard the PanAm
aircraft, the nightmare of impacts, flash fires, smoke and
explosions created utter terror and confusion. Momentarily, First
Officer Bragg grabbed for the engine fire shutoff handles above his
head. They were not there - the entire top of the fuselage had been
Moments later the
flight deck floor, together with that of the wrecked upper deck,
collapsed, spilling the uninjured flight crew and the traumatized
bodies of passengers who had been seated in the upper deck lounge
into the main deck First Class cabin below. Together with passengers
from this section of the aircraft, the crew escaped down on to the
ground through a hole torn in the port side of the fuselage.
For once, those in
the nose of the aircraft proved to be the lucky ones. Many of those
seated on the starboard side of the main cabin in the areas of the
initial impact were killed outright. On the port side, and further
back in the main cabin, many other passengers who were initially
spared injury were trapped and prevented from escaping by collapsed
sections of the starboard fuselage side. They were soon overcome by
the rapidly spreading fire.
Despite a fire under
the port wing, where the engines were still running down, many
managed to escape through the port side over-wing exits on to the
wing. But they then had to jump to the ground, some sustaining
broken legs or other injuries. Still others jumped 20 feet to the
ground from a rear door. Within one minute, the evacuation of
survivors was effectively over. Fire had now overwhelmed the
fuselage and starboard wing of the PanAm Boeing, and those who had
not already made their escape would never do so.
Because of the fog,
the tower controllers did not see the collision of the two huge
aircraft. They heard only the series of explosions, unable to
localize them or know their cause. Moments later, the crew of one of
the aircraft on the parking apron reported seeing a fire through the
fog, but again was unable to specify its exact location or cause.
tower controllers sounded the fire alarm, instructing the fire
service to be ready for an urgent departure as soon as the position
of the fire was known. Shortly afterwards an airport workman came
running to the fire station to say there was a fire "to the left of
the aircraft parking area."
Vague though this
was, it was the first indication of the fire's location. Fire
fighting vehicles left at once, but had to pick their way carefully
through the congested apron to avoid colliding with parked aircraft.
Finally they were able to make out a bright light through the fog,
and as they approached, were able to feel the heat. Then they saw
the fire itself - it was a big aircraft totally enveloped in fierce
flame, the only part visible being the fin and rudder.
As the fire service
began fighting the fire, the fog cleared slightly and they sighted
another bright light further away. Taking it to be a separated
section of the burning aircraft, some fire vehicles went on to this
fire, only to discover it was a second large aircraft burning
fiercely. All the fire vehicles then moved to concentrate on this
second aircraft because the first was obviously now utterly beyond
As a result of this
decision, the fire service were there in time to prevent the port
wing of the PanAm Boeing from being consumed by the flames (between
15 and 20 tons of fuel were subsequently recovered from it). It was
not until the early hours of the following morning that the KLM
aircraft fire was totally extinguished.
Because of the dense
fog, the tower controllers remained unaware of the exact location of
the fire for some minutes, and whether one or two aircraft were
involved. But there were five ambulances at the airport at the time
and these, following the fire fighting vehicles, were soon on the
scene. A standing airport emergency plan designed to cope with a
major disaster was quickly implemented, with further medical and
ambulance assistance coming from the city of Santa Cruz, and all the
injured survivors were soon on their way to hospitals in the city.
When a tally could
finally be taken of the cost of the horrific disaster in terms of
casualties, it was found that all 234 passengers and 14 crew members
aboard KLM's PH-BUF had perished in the intense fire. Another 326
aboard PanAm's N736PA died in the actual crash, including nine
members of the cabin crew. Amazingly, there were 70 survivors from
the PanAm aircraft, but nine of these later succumbed to their
injuries and severe burns, bringing the total number of deaths to
583. The PanAm flight crew all survived, together with the two
company staff who had boarded the aircraft at Tenerife and were
occupying jump seats on the flight deck, this nose section of the
aircraft having just missed being struck by the KLM Boeing's No 4
Because of the
magnitude of the disaster, it was agreed by the Spanish Justice
Department that pathologists from Holland and the US should work as
a team with Spanish medical authorities in the enormous task of body
identifications and, where possible, autopsies. The state of the
bodies made it impossible to perform autopsies on the remains of the
KLM flight crew.
Not far from the
site of the collision, in one of Los Rodeos Airport's cavernous
hangars, mute evidence of the worst disaster in aviation history
gradually accumulated. As emergency and medical workers completed
their tasks, row after row of dark wooden coffins progressively
filled the entire floor of the makeshift morgue in the 2500 square
meters building - by far the greatest number of fatalities that had
ever resulted from one aviation accident.
No less than 70 air
safety investigators - from Spain, The Netherlands, the USA, and
from the two airline companies involved - descended upon Los Rodeos
Airport to probe the cause of this most disastrous of all air
They found the
airport to be located on a plateau, 2000 feet above sea level, with
hills lying on either side, a factor that gives rise to somewhat
unpredictable weather and frequent low cloud in the vicinity of the
Los Redoes' single
runway, aligned southeast - northwest (Runways 12 and 30), was 3400
meters long and 45 meters wide, with 60 meters overruns at both ends.
The terminal area lies on the northeastern side of the runway, with
a main taxiway parallel to the runway connecting the main apron to
holding points at both ends of the runway (see diagram). Adjacent to
both runway holding points were smaller apron areas capable of
accommodating several airline aircraft at once. In between the
runway holding areas, four separate short taxiways linked the main
taxiway with the runway.
Three questions were
uppermost in the investigators' minds as they began their formidable
Why had Captain
Jacob van Zanten, a senior, highly experienced training captain, who
had been with the respected KLM, an airline renowned for its safety
record, for 25 years, commenced takeoff on Runway 30 without the
control tower's clearance to do so?
Why had Captain Victor Grubbs been instructed by the tower
controller to vacate the runway at Taxiway 3, one that led back
towards the main apron at an angle of 135 degrees from the runway,
rather than the far more conveniently placed 45 degree angled
Taxiway 4, leading towards the holding point for Runway 30? And
unexpected as this instruction was, why had Captain Grubbs
disregarded it? If he had made the earlier turn, the PanAm aircraft
would probably have been clear of the runway by the time the KLM
Boeing reached that point on its takeoff run.
Why did the KLM crew
not grasp the significance of the PanAm aircraft's report that it
had not yet cleared the runway, and would report again to the Tower
when it did?
inquiry at the crash site itself, the investigators found that the
distance of the KLM wreckage from the commencement of Runway 30 was
around 1835 meters. The PanAm wreckage lay 450 meters closer to the
runway threshold, the KLM aircraft having continued in Right for
about 150 meters after striking the upper fuselage of N736PA, before
falling back on to the runway and sliding a further 300 meters. Both
aircraft were completely destroyed, only the outer two thirds of the
port wing of N736PA surviving the fire.
At the moment of
impact, the PanAm aircraft was slewed across the runway at an angle
of about 45 degrees, as its crew desperately tried to maneuver out
of the path of the oncoming KLM Boeing. The latter was fully
airborne, its tail bumper having scraped the runway as a result of
over-rotation for a distance of 20 meters before it finally lifted
off only 80 meters short of N736PA.
But it was too late.
Although PH-BUF's nose undercarriage cleared N736PA’s fuselage, its
main undercarriage did not, impacting initially against the PanAm
aircraft's No 3 engine and fuselage. One of the KLM's undercarriage
bogies was wrenched off, but the rest of the main undercarriage and
the underside of PH-BUF's rear fuselage rode across the cabin top of
N736PA, shearing it off. As both aircraft exploded into flames, the
port wing of PH-BUF sliced off N763PA’s tail fin.
As there was no
evidence of any failure in either aircraft prior to the impact, and
there was every reason to suspect that the accident had resulted
from misunderstandings or a lack of adequate communication, the key
to the cause of the disaster would most probably be found in the
transcriptions of the two Boeing 747's Cockpit Voice Recorders and
the continuous tape recording of the Los Rodeos air traffic
Fortunately the CVRs
of both aircraft were recovered from the wreckage and both proved
capable of being read out satisfactorily. These readouts were
correlated with that of the control tower recording to produce a
complete, accurately timed record of all that took place on the
flight decks of both Boeing 747s and in the Los Rodeos Control Tower,
from before the time the two aircraft started their engines, up to
the instant of impact.
It was evident from
a careful analysis of all the recorded exchanges that Captain van
Zanten, as soon as he heard the ATC clearance being passed to his
crew, believed that PH-BUF had been cleared for takeoff and
immediately opened the throttles to do so.
But the clearance
given them was an airways clearance, applicable only after the
aircraft was airborne from Los Rodeos Airport, and not clearance to
Thus the fundamental
factors in the development of the accident were that PH-BUF:
Took off without being cleared to do so.
Did not heed the tower controller's instruction to "standby for
Did not abandon the takeoff when it became apparent that N736PA
might still be on the runway.
But how could a
senior airline pilot with the technical capacity and experience of
Captain van Zanten, whose demeanor during his time on the ground at
Los Rodeos seemed perfectly normal, commit such a basic error only a
few minutes afterwards - despite several warnings addressed to him?
There were a number
of factors that could have contributed to his situation:
An increasing feeling of tension as the imperative to depart
increased. Though reassured by the information radioed from KLM
Amsterdam about the duty time still available to him and his crew,
they were nevertheless committed to leaving Los Rodeos within a
relatively short time, if the flight was not to remain there
overnight - with all the resulting inconvenience to the passengers
and expense to the company.
The weather conditions at the airport had suddenly deteriorated and
the runway visibility was already uncomfortably close to the minimum
specified by KLM for takeoff. For Captain van Zanten it would have
seemed important to get airborne quickly, especially as the runway
centerline lighting was out of service. Otherwise they might have to
wait for an improvement in the weather, with the risk of exceeding
the crew's duty time limit. This anxiety to depart was apparent even
to the PanAm crew, as was evident from the latter's flight deck
conversation while they themselves were taxiing for takeoff.
Although Captain van Zanten had flown for many years on KLM's
European and intercontinental routes, he had been an instructor for
10 years, spending much of his duty time during those years in the
company's simulators at Schiphol Airport in Amsterdam. This tended
to reduce his day to day familiarity with route flying and its
procedures. At the same time his experience and high standing in the
company probably made his crew reluctant to question his decisions.
In addition, his first officer was a former DC-8 captain who had
only recently qualified to crew Boeing 747 aircraft and whose
experience on the type was limited to only 95 hours. Having now
found himself flying with the training captain who had given him his
Boeing 747 rating, he would have been even more circumspect in his
attitude to Captain van Zanten.
While the KLM crew were taxiing for takeoff, the tower controller
offered them their ATC [airways] clearance. They declined to accept
it at the time, presumably because they were engrossed in performing
their pre takeoff checks and it would have distracted them from this
vital task. But this meant that when they had finally lined up on
the runway and were in all other respects ready for takeoff, they
still had to obtain both their airways and takeoff clearances. This
fact was perhaps obscured by First Officer Meurs when, after Captain
van Zanten began to let the aircraft roll forward on completion of
the pre takeoff checks, he told the captain: "Wait ... we don't have
an ATC [airways] clearance".
First Officer Meurs'
subsequent transmission to the Tower, "KL 4805 is now ready for
takeoff and we are waiting for our ATC clearance," though ambiguous,
was in effect a simultaneous request for both clearances. That is
evidently how Captain van Zanten interpreted it, for when the Tower
transmitted the airways clearance only, he immediately accepted it
as the takeoff clearance, released the brakes and opened the
throttles. Meurs, if he in fact realized the captain's error at this
stage, did nothing more to bring it to his attention.
For Captain van
Zanten, the misunderstanding resulted in his believing they were
cleared both for takeoff and for the airway route. For the
controller on the other hand, it resulted in the conviction that
PH-BUF was still awaiting its takeoff clearance at the runway
transmission by First Officer Meurs on completing the mandatory
readback of the airways clearance when the aircraft was already six
seconds into its takeoff run, "We are now at takeoff", was then
interpreted by the controller as confirming that the aircraft was at
the "takeoff position" on the runway, awaiting its clearance to
Because it was
probably the last possible opportunity to avert the unfolding
disaster, it was nothing less than tragic that the PanAm crew's
understandably alarmed response to these transmissions, "We are
still taxiing down the runway!", coincided with the controller's
further transmission: "OK ... standby for takeoff ... I will call
you." The result was that the KLM crew heard only the controller's
"OK", followed by a squeal resulting from the simultaneous
The brief exchange
that followed between the Tower and the PanAm crew, concerning
reporting when the runway was clear, apparently fell on deaf ears as
far as the two KLM pilots were concerned, concentrating as they were
on their takeoff. But Flight Engineer Schreuder was sufficiently
concerned to query the captain about it. What prompted both pilots
to give him such an emphatic assurance that the runway was already
clear, can never be known. However, the KLM crew's overall failure
to monitor the radio communications between the Tower and the PanAm
Boeing while both aircraft were taxiing resulted in their having no
mental "picture" of its whereabouts on the airfield - a "picture"
that could have prevented the accident.
It could also be
said that a contributing factor to the accident was the fact that
the PanAm crew, while taxiing on the runway in the severely limited
visibility, bypassed Taxiway 3 where they had been instructed to
turn off and were only 150 meters from Taxiway 4. As a result of a
careful analysis of the PanAm aircraft's movements, the
investigators found that if it had in fact turned off at Taxiway 3,
in all probability no collision would have occurred.
The PanAm crew
obviously had difficulty interpreting the tower controller's
instruction. In the first place, because of language difficulties,
they were unsure whether the controller had nominated Taxiway 1 or
Taxiway 3 and, after a further exchange clarified this, they
experienced problems in identifying the actual taxiways in the
reduced visibility. Their efforts were probably not helped by the
pre takeoff checks they were conducting at the same time, and First
Officer Bragg had only a small diagram of the airport.
But none of the
taxiway intersections on the airport were indicated by markers, and
the fact that the third taxiway they saw appeared to lead back
towards the congested airport apron at an angle of 135 degrees from
the direction in which they were heading, convinced them it was
inactive and could not be the taxiway the controller meant.
Apart from the
congestion on the apron which they were backtracking on the runway
to avoid, it seemed to the PanAm crew that the controller would not
ask an aircraft as big as a Boeing 747 to make such a tight turn on
to a comparatively narrow taxiway, requiring a similarly tight 135
degree turn in the opposite direction to regain the main taxiway
leading to the runway.
Their belief was
further reinforced when they saw from the airport diagram that the
next taxiway led off the runway at a comfortable 45 degree angle to
connect with the main taxiway leading to the holding point for
Runway 30. Though they had been careful to query the Tower's initial
instruction to backtrack on the runway in the poor visibility before
presuming to enter the runway, they did not do so on this occasion,
but continued towards Taxiway 4, believing it to be the one
consideration in the fateful sequence of events leading to the
disaster was the actions and decisions of the tower controllers
themselves. In the first place, the air-field controller's command
of English left something to be desired, resulting in
misunderstandings on the part of both the American and the Dutch
crews. Secondly, the controller, as with the KLM first officer, did
not adhere to standard terminology in his communications, giving
further opportunity for misunderstanding and misinterpretation.
controller's decision to allow two aircraft to use the runway at the
same time was undoubtedly a dangerous one in weather conditions
which prevented the controller and the two aircraft concerned from
seeing one another.
In the circumstances
that had overtaken Los Rodeos Airport, there was little choice but
to do so, but the lack of visibility could have been offset by
having the aircraft read back all the Tower's instructions and
subsequently confirm their various movements and positions.
As it was, with none
of the parties in visual contact, the tower controller and the two
aircraft were depending entirely on radio communication for
knowledge of position. Only by careful read backs, and confirmation
of instructions therefore, could safety have been assured.
Against all this, it
has to be said that the controller had been on duty all day, during
which he had been under pressure handling an unusually high workload
because of the number of aircraft diverted to Los Rodeos. He also
had relatively little experience in handling Boeing 747 aircraft.
His instruction to the PanAm crew to vacate the runway at Taxiway 3
was thus a consequence of his limited appreciation of the
maneuverability of the aircraft type. He had not asked the
impossible however, as taxiing tests with a Boeing 747 during the
investigation subsequently established.
investigation determined that, even apart from the shortcomings that
existed in the radio communications and the misunderstandings that
arose from them, the accident was the final outcome of an
unfavorable coincidence of a whole chain of circumstances that
individually were relatively insignificant. If any one of these
circumstances had not been in place, the accident would not have
It was the seemingly
predestined way in which these largely everyday circumstances
happened to coincide at Los Rodeos on Sunday, March 27, 1977, that
developed the accident to its terrible inevitability.
Above all however,
the accident was an appallingly tragic lesson on the danger of
depending on radio communication alone for the safe operation and
regulation of air traffic. The facts of the accident show that
information transmitted by radio communication can be understood in
a different way to that intended, as a result of ambiguous
terminology and/or the obliteration of key words or phrases. They
demonstrate beyond doubt that the oral transmission of essential
information, via single and vulnerable radio contacts, carries with
it great potential dangers.
The primary safety
message drawn from the accident was the urgent need to improve
communication between aircraft and Tower. Such communications lagged
far behind the fail-safe principle applied to other aspects of
aviation. Radio communication, as it existed at Los Rodeos Airport
on the day of the accident, was not fail-safe.
recommended for immediate adoption as a short term improvement
The use of concise and unambiguous terminology.
Avoiding the expression "takeoff' in airways clearances.
Allowing a distinct time interval between the transmission of an
airways clearance and a takeoff clearance.
recommendations were referred to the Air Navigation Commission of
the International Civil Aviation Organization (ICAO) for study.
improvements for the introduction of fail-safe principles in
communication between aircraft and Tower were also considered. In
its most simple form, this could be no more than a red-green light
at the threshold of the runway to confirm the controller's oral
takeoff clearance. The FAA in the USA had been testing this system
at Atlantic City Airport with encouraging results.
For all who lost
loved ones, or were injured, or who were involved in other ways in
the horror at Los Rodeos Airport that fateful Sunday afternoon on
the island of Tenerife, there would have been a seemingly endless
sense of recrimination as they thought over what had happened. There
were so many "ifs" - so many small coincidences that need not have
compounded to make the tragedy inevitable.
If the bomb had not
gone off at Las Palmas, if the PanAm Boeing had been permitted to
hold instead of landing at Los Rodeos, if the KLM crew had not
decided to refuel, if the PanAm aircraft could have squeezed past
its KLM sister ship without having to wait for it to move, if the
weather had not deteriorated, if the PanAm crew had not bypassed the
No 3 taxiway, if they had not transmitted at the moment they did
when they feared the KLM aircraft was about to takeoff, if the KLM
captain had taken more notice of his flight engineer's doubt ... any
of these factors could have altered the whole course of events as
But no amount of
speculation could now change even one of them, much less bring back
those who were lost.
The best that could
be hoped for was that 583 people had not died in vain - that the
sheer magnitude of the disaster would forcibly sheet home to all
involved in aviation that, by its very nature, flying abounds with
countless opportunities for "little" things to go wrong.
That, to be
routinely safe, aviation requires constant and unswerving vigilance
on the part of all its professionals - and that those who carry such
responsibilities can never afford to take anything for granted.