Sleepy Pilot Flew Into The Hills (Korean Air Flight 801) - DISASTER BREAKDOWN
When it comes to the operation of an airplane, the one person who holds more authority over a flight than anyone else is the Commander of the Flight, the Captain. We trust that our captains are of the highest proficiency in their piloting skills. We understand that they are well experienced, have received the appropriate training from their respective airlines and so on. Airline captains are well respected people not only in their industry but often even just generally. The Captain involved in today’s discussion of an Air Disaster was one of those highly regarded and respected pilots, an award winning pilot no less.
He was by anyone’s expectation the kind person you’d want to fly your plane, and there’s no catch there he really was an exceptional pilot. But how the disaster of Korean Air Flight 801 unfolded just goes to show how even the most experienced captains are still human and so are limited by their natural bodily processes. This is the story of Korean Air Flight 801.
One of the deadliest air disaster to have ever occurred. When Korean Air Flight 801 left Seoul for Guam in the evening of August 5th, 1997, everyone on board probably expected a straight forward routine flight. 254 people were on board the Boeing 747 that evening, 237 passengers and 17 members of crew. The variant of the 747 in operation that night was actually the least popular model of the plane, the 300. In many ways the 300 is very similar in design and technological prowess as the 200 model but with perhaps the key outward distinguishing feature being the stretched upper deck. Though powered by the same engines as the previous 200 747, minor adjustments to the air frame and floorplan of the seating and stairway meant that the plane could fly faster than any 747 that came before it whilst carrying more passengers.
The 747-300, like its predecessor required three people to fly, it wouldn’t be until for the 400 model that the Flight Engineer role was eliminated. Up on the Flight Deck commanding the flight that night was 42-year-old Captain Park Yong-Chul. He was a captain of over 9,000 total flight hours. As previously mentioned, he was an award winning pilot, recognized for his efforts in the area of aviation safety. He had recently received honors for safely landing a 747 with the failure of an engine earning him recognition from not just within the airline but in the industry as a whole. Additionally he had also previously been recognized for negotiating an issue with landing gear.
The First Officer was 40-year-old Song Kyung-ho. He was a pilot of around 4000 flight hours. But the eldest member of the crew though was the Flight Engineer, 57-year-old Nam Suk-hoon. As the pilots cruised through the night sky, the date switched over into the early hours of August 6th. Flight 801 was for the most part an uneventful flight aside from some patches of turbulence and at one point, they actually requested to deviate from their flight path to avoid storms.
We should though, look towards the approach into Guam to see how the accident unfolded. First off, Guam is located in the Western Pacific Ocean. It’s an American Territory home to about 168,000 people with a large Pacific Islander population.
The main entry and exit point on the Island is Guam’s Airport located here, right in the center of the Island. Historically the airport and the Island as a whole was of a key strategic advantage to the United States during the Second World War, so Guam airport is not to be confused with the other airfields and airbases located here. The Guam Airport itself has two runways and the active runway in use on the night of the accident was runway 06 Left. Like many international airports all over the world, the Guam airport is and was at the time equipped with full instrument landing capabilities.
The Instrument Landing System (ILS) can send out lateral and altitude information to an aircraft’s flight computer so that the autopilot can perform much of the approach and landing process. It has two main components that can operate separately but are often combined. The Localizer is the lateral system.
This gives out the information that lines the plane up with the runway. As you’d expect a very useful tool. But the magic really happens when this is combined with the glideslope, the vertical component.
Following the signal of the glide slope a plane can be gently sloped to the beginning of the runway even in poor weather conditions. A pilot may take-over at any point but if a plane is equipped with an Auto-land function it may even just land itself. These technological advancements have drastically reduced the workload for pilots. It was around 1am. For approach into Guam that evening in 1997, the pilots of flight 801 were cleared for their instrument approach for Runway 06 Left but were informed that the Glide Slope was inoperative, it had been taken out of service for scheduled maintenance, it wasn’t working. The localizer however was still functional.
In this case the pilots would perform a non-precison instrument approach. Captain Park at 1:11 in the morning would begin a briefing to the other crew members about their approach option but would only give them a Short briefing as stated in the accident report. So let’s take a moment to go over how the non-precision approach was supposed to work before going over what actually happened that night. As already mentioned, the two components of the ILS are separate. So whilst the Glideslope was down the Localizer was still working.
The pilots would lock onto and establish themselves on the localizer but still needed altitude guidance, especially on that night as visibility was reduce as rain showered the Guam airport and island. The pilots would need to consult the instrument approach chart for this runway which would give them the details surrounding a stepping procedure. Now it needs to be noted here before we go into this that the flight crew were using a chart that was dated from January 1996. A newer chart was published in August of 1996 with some notable changes in key altitudes. So what we’re going to do here is breakdown the approach the pilots should have done that night.
The procedure that was put in place for this scenario. But we’ll also make additional notes in reference to the chart the pilots possessed where necessary. Even though it was outdated, strictly adhering to it would have still guided them to the airport without accident. Anyway, this was what the procedure says... As normal flight 801 would descend down to 2500 feet and intercept a waypoint called “FLAKE” Think of FLAKE as the entry point of the approach path. Once reaching this waypoint they should be lined up with the runway and from here they would descend down to 2000 until they reach what is called the Outer Marker.
The Outer Marker is one of three different types of Marker Beacons. These are simple radio beacons used in aviation. They are so simple they literally just transmit beeps and boops and flash a light in the cockpit. The Outer Marker flashes blue and sounds something like this...
-outer marker- There are also Middle and Inner Markers. The Middle Marker flashes Yellow with shorter beeps in sort of a rhythm and the Inner Marker flashes White with high pitched fast beeps. So now at 2000 feet, they would wait until they got the signal from the Outer Marker or use a reference of 1.6 miles from the NIMITZ VOR, where the next descent down to 1440 would
begin. They should be at 1440 by the time they reach the NIMITZ VOR. On the pilot’s chart this was listed as 1300.
NIMITZ gets its name from the hill that is nearby. infact there are a number of hills and peaks in this region, and some these were also detailed in the airport charts. In theory though pilots would be staying clear of these obstructions when adhering to the altitude guidance on the chart. However it should be noted that a 700 foot obstruction at the VOR was not included in the chart the pilots were familiar with. The pilots can also receive distance information from the NIMITZ beacon. Unlike a lot of other airports this distance measuring system is not located at the airport but instead southwest of the Airport about 3 miles short of the runway.
Once reaching NIMITZ, from there they would begin a steady descent until the runway comes into view and land visually. Now Guam is an airport that Captain Park was actually familiar with. He had flown there several times before. Still he was a man known to take preparation and flight planning very seriously. Himself and his first officer took time to refamiliarize themselves with the airport in Guam before even setting off on the journey.
But as they approached the island, the outlook in terms of weather was showing heavy rain storms. The captain went on record to exclaim that he was feeling sleepy. And this is a very key point of interest. You see, Captain Park wasn’t actually supposed to be commanding this flight. He was scheduled to captain a much longer flight to Dubai. However his previous flight was delayed and therefore he didn’t have the required rest time to be able to take that flight.
So instead he was rescheduled onto this shorter flight. Conversations recorded on the Cockpit Voice Recording revealed that the Captain felt he was being heavily worked. He made comments about the hours he was on duty and how Korean Air made pilots of the 747s work maximum hours. Evidently, he said it himself, he was feeling sleepy and was probably looking forward to getting some rest.
I feel like it should go without saying because it is the case with almost any job, but flying a plane becomes a lot more difficult when one is fighting sleepiness. Tired, in poor weather, rain, reduced visibility and without a glideslope, this pilot was facing a lot of pressure. At 1:35 the final approach was commended, the 747 connected with the localizer at the airport and the plane was about to make its turn for final, now let’s see where things started to go a bit off course. At this time something rather peculiar occurred. The plane appeared to receive a glideslope signal.
This certainly caught the attention of the pilots, especially Captain Park. The Glideslope was supposed to be down, they weren’t expecting it come to life. What is believed to have happened was the plane picked up some sort of rogue or erroneous signal that activated the system on their end. Confusion would only continue to grow as literally seconds later the approach controller they were in communication with reminded them that the glideslope was unusable. The time was now 1:40 the plane was turning as it locked onto the ILS. As expected at 2500 feet they intercepted the FLAKE waypoint.
Flight 801 was handed off from the approach controller to the tower who then promptly cleared them for landing onto Runway 06 Left. The 747 was now descending through 2000. It was here at precisely 1:41 in the morning that things started to go wrong. Instead of following the procedure and levelling off at 2000 until reaching the Outer Marker they continued to descend. Drifting below their flight path.
None of the pilots had noticed this. Or at least they never spoke up about it at this point, which would later be cause for investigators to criticize Korean Air’s pilot training. Pilots, if they have noticed a mistake or should something be wrong, should be encouraged to speak up and challenge the actions of other pilots where necessary.
The tired captain fixated on the glideslope situation and also in the middle of configuring the plane for landing and doing checklists and without seeing much outside in the rain, the plane continued to drop lower and lower toward the range of hills below. The conversation about the glideslope would continue and other flight crew members reminded the captain that is was non-functional. The First Officer also noted to the captain that the runway was not in sight. They reached the Outer Marker point below their expected altitude.
Now to note here that the audible alert this was supposed to give out was not heard on the cockpit voice recording. The words of the pilots gave no indication as to whether or not they acknowledged the flashing blue light in the cockpit. Though the Outer Marker was test after the accident and was deemed to be in working order. Even without this acknowledgment it is noted in the approach chart that they should have levelled off again at this point which was noted to have been 1.6 miles from the NIMITZ VOR.
It is believed by investigators that the pilots may have been mistaken in using this distance information. Believing it was showing distance to the airport and expecting the runway to come into view when it reached zero. When in reality it was 3 miles further ahead. At around this time the plane entered a patch of heavy rain, likely obscuring the view outside further. The pilots were now only seconds from disaster.
The ground proximity warning system had sounded out that they were approaching the terrain below. Unable to see any sign of the airport the first officer again says that the Runway was not in sight. Still the captain under the effects of sleep fatigue continued even as the plane was approaching the minimums height. The Ground Proximity Warning System makes the Sink Rate alert to tell the pilots they are descending too quickly.
It then calls out two hundred, then rather quickly, one hundred, an indication that the plane was approaching steep terrain. The First Officer Suggested a Go-around. At precisely 1:42 and 22 seconds, the Captain called for the Go-Around.
However by this point it was too late. Due to a loss of situational awareness by the flight crew including the captain facing fatigue, they had failed to execute the non-precison approach accordingly and failed to make the required steps. Because of this they drifted into a conflict with the terrain when they should have levelled off at the required altitudes. Korean Air Flight 801 impacted the hillside just short of the NIMITZ VOR.
Over the course of the following seconds the plane carved its way through the hills breaking up into multiple sections. The crash occurred over a span of mere seconds. By at the time the plane actually came to a rest, no one outside of the plane really knew what had happened.
The Tower controller was left confused as to why flight 801 had not landed yet even after they cleared them for landing. A recording of that very conversation between two controllers was actually released... Once it was established that the plane was missing, search and rescue teams went out into the hills.
The devastation the crash left in its wake made it hard for rescuers to reach the wreckage. The plane already crashed into a remote part of island; rescuers also had to content with the weather. As the plane came over the hills it destroyed an oil pipeline blocking the only road access to the crash site.
It took first responders about an hour to reach the plane. In that time a handful of passengers and a few flight attendants had managed to escape. It is unclear how many people died from the crash itself.
However reports from survivors suggest that some who did survive the initial crash still perished. As a post-crash fire raged across the accident site, a rather sad description of events suggested that the voices of those calling help, fell silent. And they did not make it out of the plane. Among those initial survivors was a 44-year-old Japanese Woman by the name of Shigeko Matsuda. She was travelling to Guam with her 11-year-old Daughter Rika who was only small girl and was largely uninjured in the crash. The mother unable to free herself from the wreckage encouraged her daughter to leave the plane without her.
Shigeko died in the fire and 11-year-old Rika along with a flight attendant were rescued by non-other than the Governor of Guam who assisted in the rescue operation that night. Democrat politician Carl Gutierrez. In total there were 229 deaths and 25 survivors. The loss of Korean Air Flight 801 was one of the deadliest Air Disasters involving South Korea. It came during a time when Korean Air was seen as seen as an air carrier with a poor safety record. Investigators put the accident down to Pilot Error citing the pilot’s fatigue, failure to appropriately brief his crew for the Localizer only approach, further poor communication between the crew and insufficient training at Korean Air.
However investigators did not stop at the operation of the plane. Criticism was leveled at the Federal Aviation Administration who made an exception for the Guam airport to switch off a key piece of equipment that could have prevented the crash. A system called the Minimum Safety Altitude Warning or MSAW, alerts Air Traffic Control if an aircraft is about to enter a controlled flight into terrain scenario, exactly like what happened in this case.
The MSAW was disabled, switched off because in the case of Guam it was known for causing nuisance alerts. To interject with my own opinion I find this to be a rather frustrating aspect of this disaster. Part of the reason flying is as safe as it is today, is because we have technology like this. When we know it’s there to prevent accidents and save lives turning it off is just unacceptable. It was determined that if the MSAW system had been on, there would have been sufficient time for the plane to be notified and the accident may not have occurred. One surviving passenger, a helicopter pilot no less, a man by the name of Barry Small from New Zealand, made a number of observations himself.
Drawing attention to the design of passenger seating. You see, A crossbar across the length of the seat could have injured passengers when the crash occurred, as Mr. Small himself had broken a leg this way. If this had injured other passengers, it could have inhibited their escape further contributing to the higher death toll. Mr. Small also made note of the storage of Duty Free Alcohol in the cabin.
He believes that the post-crash fire was enabled by an environment in the upper part of the fuselage. Duty Free Alcohol was stored in the overhead compartments which also happens to be in close proximity the oxygen containers that supply those passenger oxygen masks. Mr. Small drew attention to this as he was of the belief that this mixture of alcohol in an oxygen enriched environment contributed to the post-crash fire. In the aftermath of flight 801, new laws were passed that allowed the victims and relatives of those involved in plane accidents to receive assistance from the US government in the event of emergencies like this even if it involves a foreign carrier.
In the years after Korean Air drastically improved its safety record. Though in the late 1990s there were further accidents involving the airline’s Cargo branch, since 1999 there has never been a fatal incident involving the airline. Patreon Outro Hellooooooo Everyone.
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2023-05-17 15:03
