Singapore Airways B747-400 Wrong Runway Take-off in
will see that Taiwan does not entirely escape blame
in theASC report.
reports by ASC and MOT are very thorough and leave no stones unturned in the above areas; lots of lessons
noted and actions have been taken by both CKS and SIA to rectify theshortcomings
Both approaches in investigations are correct .
But what alarmed me was the formatting of the Final Analysis of ASC which
classified the Causal Factors as:
"(1) “findings related to probable causes” which identify elements that
have been shown to operate or almost certainly have operated in the accident; (
please note the operative word: operated.)
In short the investigation of the causal factors relating to theaccident,
will be entirely focused on the Pilot and the weather, and deficiencies of airport
system and other contributing factors were relegated to Risks.
As a result, the concluding "Probable causes" will, for all
intents and purposes, always be on the weather and the pilot even before the ASC started its analysis of the Probable causes "
Even though Dr Yong Kay (the chairman) has qualified subsequently that Risk Factors
play an equal and critical role as causal factors in the accident, whether we like it or not, it is only
natural for both sides to adopt a "self-protection" mode in this
Not sure how long 05R had been inactive as a runway. I had
heard rumours it was as much as 12 years! Is
any record of when the last time 05R was
actually used for takeoffs and/or landings? How long have the
Taiwanese maintained this hazard to operations, a taxiway marked as an active
runway? Might as well put VASI's on Mt.Fuji.
1. The Pilots failed to determine that the runway condition should have
been classified as ‘contaminated’ due to the inevitable buildup of standing
water under cyclone conditions. This determination would have downgraded the cross-wind limit for takeoff
from 45 knots (wet runway) to 15 knots (contaminated runway) and therefore prevented the scheduled departure.
2. The Pilots' low-visibility taxiing performance was deficient during the final stage of taxi, and their navigation procedure was
inadequate and did not utilize runway charts, signage, markings or cockpit
instruments to guide them to the correct runway. The attention of the co-pilot Latiff
and the relief pilot Ng was ‘inside’ the cockpit focused on the pre-takeoff checklist and
calculating the cross-wind component. Only Captain Foong’s
attention was ‘outside’ the cockpit focused on taxiing slowly in the slippery conditions and
following the green taxiway lights to the runway.
3. The reason Captain Foong made a premature turn onto runway 05R was
i) he had the false impression that ATC could
see the aircraft. He was under that
impression because ATC issued his takeoff clearance just as he reached the end of the taxiway and was beginning his
turn onto the runway. Co-pilot Latiff also
confirmed that the timing of the takeoff clearance gave him the impression that everything was
ii) The captain did not use the runway chart or the compass to guide him to the correct runway. Instead he
stated that he “followed the green taxiway lights” despite the fact that this technique is not
as per Heathrow and could/should
not be used at CKS (where visual navigation is required).
iii) He also failed to notice signs, markings and
lights which indicated he was turning onto the wrong runway. These included the green taxiway lights to 05L
(which were more widely spaced than normal), a clearly illuminated 05R sign
as he turned into the runway, and the 05R marking painted on the runway in front of him as he
lined up for take-off. But the first link in the chain was that the FIRST taxiway
green centre-line light leading across 05R threshold to the 05L runway was unserviceable. And the second light (on from the u/s one) was DIM. The first serviceable centre-line
light was distantly 116m away (further on and across the far side of the 05R threshold). Yellow taxi-way centre-line markings
did not continue across the 05R threshold (between the 05R piano-keys) – as required by ICAO. Only 4/16
centre-line (lead-on to 05L) lights, as required by ICAO, were provided (and
two of those were u/s). So what Cpt Foong had instead, in his clearly-lit
foreground, was a very seductive set
of 16 closely spaced Centre-line green lights leading him onto 05R.
they held for takeoff, all 3 pilots thought they saw a ‘normal runway scene’
and failed to recognize crucial indicators that they were on the wrong runway,
the center runway lights were green and not white (a printout record from
calibration and maintenance equipment showed that the center runway lights
were on 4 minutes before the crash)
ii) that it did not have touch-down lights or high-intensity runway edge
lights (lack of evidence from security and passenger video, together with
eyewitness testimony from the pilot of a plane on the taxiway 110m from the
05R threshold indicated that the runway edge lights were almost certainly
iii) that the runway was 15m narrower than it should have been
iv) that the PVD instrument had not unshuttered.
5. Several factors were speculated to have led to these navigational deficiencies and
observational failures including that:
i) the pilots were accustomed to using
runway 06 and had not used 05L for 2-3 years and were therefore unfamiliar with it.
ii) Although having read a NOTAM concerning the construction on 05R, the pilots had not read the SIA INTAM that contained
important information on the status of 05R’s center and edge lights
iii) Captain Foong had not been officially trained in low-visibility taxiing
iv) The pilots all had an incomplete understanding of why the PVD did not unshutter
and incomplete training on the operational context of its
v) The green taxiway lighting that led to 05L was abnormally spaced and
instead of being 7.5m apart, each light was 23m apart
vi) All 3 pilots were fixated on
taking-off quickly before the weather conditions deteriorated further and prevented takeoff
(although there was no evidence of ‘organizational pressure’ on the pilots to depart on schedule
6. The CKS airport authority was derelict in their maintenance and safety
responsibilities. By not placing mandatory construction warnings at the entrance of 05R, they failed to address the risk that aircraft might
inadvertently attempt to take off from a partially closed runway. They also
failed to adequately maintain taxiway lights and marking to accepted
Maybe I am missing something, but this seems a pretty unbiased statement of
facts. If you look at the NTSB comments in the appendix, they seem to think so too. Don’t be
fooled by the spin doctors.
i.e. I think the wrong turn into
05R is not the BIG issue here. One can make a
wrong turn (and I think this not as uncommon as one would have thought?)
without the same disastrous outcome. i.e.:
a. realize the mistake and turn
out again, or
b. don’t realize the mistake but still
take off from the wrong but
operational runway ..... (safely!?).
The really bigissue is being able to attempt take-off from a CLOSED (and
wholly obstructed) runway. Some would insist that it was a PARTIALLY closed
runway and therefore not technically 'CLOSED'.
How is one supposed to make that distinction if the difference is only
'apparent' as you are passing 'V1'? Some would counter that the centre lights
were not white and there were no
touch-down lights and that the edge lights
"were almost certainly off" that this was not a runway but a
taxiway. Some will say that the PVD "had not
unshuttered" hence this was a wrong runway.
Then how come "all 3 pilots thought they saw a ‘normal
runway scene’ " and thought they were on the correct runway?
this explanation here.
"Co-pilot Latiff also confirmed
that the timing of the takeoff clearance
gave him the impression that everything was in
However, if you look at the report, the elapsed time
between clearance and start of the roll is
relatively considerable… in the order of 80
seconds. Partly explained by the 5 kts taxi speed, I know.... but if their
"ready" call was premature (clearly debatable), then ATC’s natural response to offer clearance (no traffic-and
they can’t see them anyway) whilst
still on taxiway NP might have induced the pilot to more readily
accept the "lead-on" picture he saw at N1/05R intersection, given
the time elapsed between the two. The longer the time-elapse is, the more willing he
becomes to accept the notion that he is
indeed on the correct runway.
If the takeoff clearance had only just been
issued (later, during the turn into N1), the pressure to
accept those compelling green lights might have been less.
onto the wrong runway was the cause of the accident and the main issue here!
But equally, because humans are naturally fallible and indulge in secretive
wishful thinking, the why and how that led the pilots into turning onto the wrong runway is what needs to
From where I sit, the following issues are the main areas/factors:
The inclement weather,
The night environment,
Signage, lightings, markings of the taxiway and failure to obstruct
entry into the 05R Runway
Air Traffic control : Low Visibility Procedures
(LVP) taxy monitoring and issue of takeoff
Take off procedures of SIA: for confirmation of correct runway.
report avoids unveiling the "golden nugget" and instead opts for a
mish-mash of comments and diatribe on several elements that make up the whole.Yes, an accident is usually the result of a chain of events but
the "probable cause" theory is still the best way to go, in my opinion.
What was the last chain in the link that made the accident inevitable? Turning on
to the wrong runway is about as clear
an error as you can get. However this obviously wasn’t thelast link in the chain, although if the NTSB had been at the helm, you can bet your bottom
dollar that this would have been their conclusion. I see that their recommendations centre almost
entirely on developing cockpit moving-map nav
displays for ground operations.
The Psychology of What they did - AND WHY
How Dreadle Might have Stopped SQ006
Large Scale Map of Taipei Runway Arrangement (large
format jpeg [right-click/save as - to view off line])
PowerPoint File of What
Pilot Saw as He approached Runway Entry Points [save and view off-line]
combination of horrendous weather, poor airport
markings, and a lack of adequate precautions by both the pilots and air
traffic controllers set the stage for the crash of a
Singapore Airlines jumbo jet at Taipei's ChiangKai-shekInternationalAirport (CKS) 18 months
ago, a report released today said.
report, issued by Taiwan's Aviation Safety
Council (ASC), does not include a probable cause. It lists three sets of
findings, including eight "Elements Related To Probable Causes"
that either contributed or "almost
certainly" contributed to the accident.
crew of Singapore Flight 006, Boeing 747-400 9V-SPK (pictured),
attempted to take off in strong winds and heavy rain brought in by the approaching
Typhoon Xangsane on Oct. 31, 2000. Flight 006's
crew was cleared to taxi to CKS's Runway 05 Left, but instead turned off
early and lined up on Runway 05 Right, which was closed for construction.
flight crew did not review the taxi route in a
manner sufficient to ensure they all understood
that the route to Runway 05L included the need" to
pass Runway 05R, the report said.
crew had CKS taxi charts, but "none of the flight
crewmembers verified the taxi route,"
which included a 90-degree turn from one taxiway to a second taxiway,
followed by another 90-degree turn
onto Runway 05L.
the crew made a 180-degree turn from the first taxiway
directly onto Runway 05R. "None of the flight crew
members confirmed orally which runway they had
entered," the report said.
"The flight crew lost situational awareness and commenced takeoff from
the wrong runway."
747 struck concrete barriers and construction equipment about 3,300 feet
down the runway. The plane broke apart and caught
fire. Eighty-three of the 179 people on
board were killed.
ASC report cited several problems at CKS as
"findings related to risk." Although Runway 05R was closed, its
ends were being used as taxiways. The closed runway had green centerline
lights that designated it as a taxiway, but investigators said there was a
"lack of adequate warnings" at the runway's entrance
that would have provided "a potential last defense" to a crew
mistaking the strip as an active runway.
also found several problems with the lighting on and
around Runway 05R, including inoperative bulbs and an inadequate number of
lights. These and other signage and
marking problems likely contributed to the crew's loss of
awareness, the report said.
local controller "did not issue progressive taxi/ground movement
instructions and did not use the low-visibility
taxi phraseology to inform the flight crew to
slow down during taxi," the report says.
Investigators point out that the crew could have
requested the step-by-step taxi instructions,
but did not.
did not have Airport Surface Detection Equipment installed. It is not clear
whether the aircraft
movement-tracking system would have helped prevent the accident, because
heavy precipitation can hinder the radar
presentation, investigators said.
made 60 recommendations to nine organizations as part of the report, including
14 to Taiwan's Civil
Aeronautics Administration, 10 to the airline, and
eight to the International Civil Aviation
Organization (ICAO). Many of them focused on
improving closed-runway procedures and adding ground radar. Several
recommendations to Boeing, the U.S. FAA and Europe's JAA touched on
evacuation standards and equipment design.
Airlines said it "generally" accepted the report's
findings, but took exception to the emphasis on its
crew's role. "It appears that the ASC report does
not give due weight to the deficiencies
found at CKSAirport," the airline said in a
statement. "We believe these deficiencies
misled the pilots into taking off from the wrong
airline also said the ATC procedures
leading up to the crash deserve
more scrutiny. "The air traffic controllers cleared the flight for
takeoff at the critical moment that it was
taxiing towards Runway 05R," the airline said.
"This reinforced the crew's belief
that they were entering the correct runway.
In low-visibility conditions, air traffic controllers at CKSAirport are required to
determine the position of the aircraft before
issuing takeoff clearances. They did not follow this procedure."
airline said it has changed several procedures and beefed up training based
on lessons learned from the investigation as
well as a parallel one done by Singapore's Ministry of
Transport. "We will study the recommendations
in the ASC and the MOT reports in
more detail, and we will implement any recommendations that would further enhance
safety," the airline said.
Poor Markings, Missed Clues Set Up Singapore Crash
By Sean Broderick
23-Feb-2001 3:58 PM U.S. EST
Pilots of the Singapore Airlines
jumbo jet that crashed last October missed clues that showed they were taking off on
a closed runway, and significant airport marking deficiencies helped fool the pilots into
thinking they were on the correct strip,
factual reports on the crash investigation
released Friday indicate.
Flight 006, flown by
the Boeing 747-400 carrying registration No.
9V-SPK (pictured), was cleared to depart on Chiang Kai-Shek
International Airport's (CKS) Runway 05L last Oct. 31. Instead, the pilots attempted to
take off on a parallel runway, 05R, which was closed to operations at the time due to
construction in the center of the runway but was
being used as a taxiway at each end. The plane was destroyed after hitting
construction equipment sitting on 05R. Eighty-three of the 179 people on board
Weather at the time of the crash, which
happened at local time Oct. 31,
was rainy and windy due to a typhoon bearing down on Taipei. Visibility was
about 500 meters.
Because of the poor weather and nighttime
conditions, the pilot and co-pilot elected to switch on the "para-visual
display" (PVD), facts gathered by investigators
and released by Taiwan's Aviation Safety
Council (ASC) show. The PVD, a mechanical instrument mounted on a panel in
front of each pilot position that helps the pilots line up and stay
on a given runway's centerline, works with the plane's
instrumentation to monitor a runway's Instrument Landing System (ILS) signal.
The PVD resembles a
barber pole sitting on its side, with black stripes on a white background. It
is not mandatory equipment, and carriers that use it only require it to be
activated when visibility is much worse - 50 meters or below, in most cases -
than the visibility the Flight 006 crew was
When the aircraft gets in
range of the ILS runway signal that the plane is tuned to,
a small shutter on the PVD opens,
revealing the black-and-white pattern. The stripes remain
stationary so long as the plane is on the runway centerline.
When it moves left or right, the stripes move in the direction of the runway centerline,
helping guide the pilots back to the middle of the strip.
Both the pilot and first
officer of Flight 006 switched on their PVDs at the gate, investigators
found. When the aircraft taxied into position at what the crewmembers thought
was the end of 05L, all three pilots - including a
relief pilot sitting in the cockpit - noticed the PVD had not
activated. But since visibility was well above the level that requires
PVD usage and they could all see
centerline marking lights clearly, the pilots decided to
"The PVD hasn't
lined up," the co-pilot said as the plane turned onto
05R, according to the cockpit voice
"Never mind. We
can see the runway," the captain responded.
"Not so bad."
The visual takeoff
may have caused the pilots to miss two
other clues on their instruments that
could have indicated a problem. When a 747's ILS is tuned for a specific
takeoff runway, two indicators appear on the plane's primary
flight display (PFD). A pink diamond shows the aircraft's position
relative to the runway's ILS localizer, and a green
trapezoid shows the runway, which
should be centered and just below the PFD's horizon when the plane is aligned
properly. When the plane is not
aligned with the runway centerline, both indicators are well
off to the display's side.
lights could have served as another clue to the pilots. The captain
told investigators that he "followed the curved centerline
lights" onto 05R, an ASC report said. "He commented that he was
attracted to the bright centerline lights leading onto the runway."
lights that run all the way down 05R are
green, designating it as a taxiway. Centerline lights on runways are white at
the beginning and later change to red near the end. While a
similar set of green taxiway lights leads from N1 onto 05L, the lights running down
the middle of 05L are white.
Both 05L and 05R
have bi-directional runway edge lights that appear white, yellow, or red, ASC
said. The two sets of lights are identical. The CKS ground controller working
on the night of the accident told
investigators that the 05L edge lights
were on, but the 05R edge lights were not. Soon after the accident, the captain told
investigators that he was "80% sure" he saw edge lights along 05R,
but in follow-up interviews, he was "less sure," ASC said.
While the pilots may have
missed some clues regarding their wrong-runway
mistake, they were almost surely hampered by airport
surface marking deficiencies.
As they followed taxiway
lights down NP and turned right onto N1, they did not see any
centerline lights straight in front of them that would have
led them to 05L. They did, however, clearly see the curving set of
taxiway centerline lights, spaced about 7.5 meters (25 feet) apart, leading
to 05R from N1's south end.
surveyed CKS four days after the crash, they found that the two taxiway lights
designed to lead aircraft further down N1 past the inactive 5R to the active 5L runway
were not working perfectly. One was not illuminated at all, and the other was "less
intense than the other lights." The
lights, spaced about 25m apart, run straight down N1's centerline and meet up
with another set of curved, green taxiway lights that
connect 05R's centerline with N1's north end.
As Flight 006's captain
taxied down N1 and approached 05R, he was "focused on the image of the runway to his
right, and he did not notice any further green lights ahead
and along the extension of N1," he told
several other lighting and marking problems. Some of the runway edge lights
on both 05L and 05R were either broken or
"aligned away from the direction of the runway
length," ASC said.
Also, there was nothing over the 05R threshold
markings that indicated the runway was closed.
Runway 05R had been
closed since mid-September for needed pavement repairs. The plan was to
convert it into a full-time taxiway on Nov. 1, but the timeline was pushed
back before the Flight 006 crash. Before being closed, it
was used for visual departures only.
The Flight 006
captain told investigators he was aware of 05R's status. He had used the runway in the past; his last
departure on it was "two or three years" ago, ASC said. The
captain's last flight to Taipei before Oct. 31 was
sometime in early to mid-September, the agency's Human
Factors report said.
most often used Runway 06, the parallel runway
south of CKS's terminal, because it is "closer to the parking bays used
by the company," the Flight 006 captain
told ASC. But 06 is a Category I ILS strip, and the weather on Oct. 31
persuaded the pilot to request 05L, a Category II runway,
because it is "longer and would therefore afford better
margins for the prevailing wet runway conditions."