PASSENGER PLANE DISASTERS Part one

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Flight phobics are sometimes so afraid of air travel; they'll even find alternative ways to get to their chosen destinations. But is it really safer to drive or take a bus than it is to fly to your destination?

It is much safer to fly to your destination than drive to your destination. When broken down on a per year basis, your odds of dying in a vehicle crash would somewhere in between one in 4,000. Currently, roughly 40,000 people per year die in car accidents in the United States alone.

There is one-in-5.3 million chance of being in an airplane crash. which means that you could expect to fly on the Ssame route every day, for 14,716 years, before a mishap occurred. Fatal airliner accidents in 2018, were 556 deaths, compared with 10 accidents and 44 lives lost in 2017, the safest year in aviation history.

I have been in a car crash in which I was hospitalized and I survived a passenger plane crash without any injuries at all. This means that the statistics listed above don’t necessarily apply to everyone, however, both kinds of crashes can be horrific.    

For example, many years ago there was a horrific car crash on a highway in Ontario, Canada’s largest province. Many cars were involved in the crash and a number of the cars caught fire. A 14-year-old girl was trapped in her parent’s car and when the fire reached her and she was being burned alive, she screamed, “Why do I have to die?”  That was a horrific way to die.

There have been instances when planes exploded in the air and  the passengers were thrust out of the planes and their bodies were submitted to hundreds of miles an hour in freezing air before they died of suffocation.

In this article, I am going to tell you about the largest loss of passenger’s lives in a double plane crash when the wo planes were still on the ground.

On March 27, 1977, at Los Rodeos airport in Tenerife, Pan Am Flight 1736 was sitting on the taxiway waiting to take off. A thick fog obscured the approach of KLM 4805, as it bore directly towards them while they too were on the tarmac.

KLM Flight 4805 was a charter flight for Holland International Travel Group and had arrived from Amsterdam Airport Schiphol, Netherlands.^[8] Its cockpit crew consisted  of  Captain Jacob Veldhuyzen van Zanten who was age  50 and  first officer Klaas Meurs, age 42, and flight engineer Willem Schreuder, age 48. At the time of the accident, Veldhuyzen van Zanten was KLM's chief flight instructor, with 11,700 flight hours, of which 1,545 hours were on the 747. Meurs had 9,200 flight hours, of which 95 hours were on the 747. Schreuder had 15,210 flight hours, of which 540 hours were on the 747.

A terrorist incident at Gran Canaria Airport had caused many flights to be diverted to Los Rodeos, including the two aircraft involved in the fatal accident. The airport quickly became congested with parked airplanes blocking the only taxiway and forcing departing aircraft to taxi on the runway instead. Patches of thick fog were drifting across the airfield, hence visibility was greatly reduced for pilots and the control tower.

The collision between two passenger plains occurred when the KLM airliner initiated its  takeoff run while the Pan Am airliner, shrouded in fog, was still on the runway and about to turn off onto the taxiway. The impact and resulting fire killed everyone on board KLM 4805 and most of the occupants of Pan Am 1736, with only 61 survivors in the front section of the aircraft

The subsequent investigation by Spanish authorities concluded that the primary cause of the accident was the KLM captain's decision to take off in the mistaken belief that a takeoff clearance from air traffic control (ATC) had been issued. Dutch investigators placed a greater emphasis on mutual misunderstanding in radio communications between the KLM crew and ATC,^[5] but ultimately KLM admitted that their crew was responsible for the accident and the airline agreed to financially compensate the relatives of all of the victims.

The disaster had a lasting influence on the industry, highlighting in particular the vital importance of using standardized phraseology in radio communications. Cockpit procedures were also reviewed, contributing to the establishment of crew resource management as a fundamental part of airline pilots' training.

Tenerife was an unscheduled stop for both flights. Their destination was Gran Canaria International Airport (also known as Las Palmas Airport or Gando Airport), serving Las Palmas on the nearby island of Gran Canaria. Both islands are part of the Canary Islands, an autonomous community of Spain located in the Atlantic Ocean off the southwest coast of Morocco.

One of the aircraft was a Boeing 747-206B, registration PH-BUF, named Rijn (Rhine). The KLM jet was carrying 14 crew members and 235 passengers, including 52 children. Most of the KLM passengers were Dutch; also on board were 4 Germans, 2 Austrians and 2 Americans. After the aircraft landed at Tenerife, the passengers were transported to the airport terminal. One of the inbound passengers, who lived on the island with her boyfriend, chose not to re-board the 747, leaving 23 to fly in that plane .

The Pan Am Flight 1736 had originated at Los Angeles International Airport, with an intermediate stop at New York's John F. Kennedy International Airport (JFK). The aircraft was a Boeing 747-121, registration N736PA, named Clipper Victor. Of the 380 passengers (mostly of retirement age, but including two children), 14 had boarded in New York, where the crew was also changed. The new crew consisted of captain Victor Grubbs, age 56, first officer Robert Bragg, age 39, flight engineer George Warns, age 46, and 13 flight attendants. At the time of the accident, Grubbs had 21,043 hours of flight time, of which 564 hours were on the 747. Bragg had 10,800 flight hours, of which 2,796 hours were on the 747. Warns had 15,210 flight hours, of which 559 hours were on the 747.

This particular aircraft had operated the inaugural 747 commercial flight on January 22, 1970.^[8] On August 2, 1970, in its first year of service, it also became the first 747 to be hijacked: en route between JFK and Luis Muñoz Marín International Airport in San Juan, Puerto Rico, it was diverted to José Martí International Airport in Havana, Cuba.^[1

Both flights had been routine until they approached the islands. At 13:15, a bomb planted by the separatist Canary Islands Independence Movement exploded in the terminal of Gran Canaria International Airport, injuring eight people. There had been a phone call warning of the bomb, and another call received soon afterwards made claims of a second bomb at the airport. The civil aviation authorities had therefore closed the airport temporarily after the explosion, and all incoming flights bound for Gran Canaria had been diverted to Los Rodeos, including the two Boeing 747 aircraft involved in the disaster. The Pan Am crew indicated that they would prefer to circle in a holding pattern until landing clearance was given (they had enough fuel to safely stay in the air for 2 more hours), but they were ordered to divert to Tenerife.

Both flights had been routine until they approached the islands. At 13:15, a bomb planted by the separatist Canary Islands Independence Movement exploded in the terminal of Gran Canaria International Airport, injuring eight people.^[13] There had been a phone call warning of the bomb, and another call received soon afterwards made claims of a second bomb at the airport. The civil aviation authorities had therefore closed the airport temporarily after the explosion, and all incoming flights bound for Gran Canaria had been diverted to Los Rodeos, including the two Boeing 747 aircraft involved in the disaster.^[4] The Pan Am crew indicated that they would prefer to circle in a holding pattern until landing clearance was given (they had enough fuel to safely stay in the air for 2 more hours), but they were ordered to divert to Tenerife.^[14]

Los Rodeos was a regional airport that could not easily accommodate all of the traffic diverted from Gran Canaria, which included five large airliners. The airport had only one runway and one major taxiway running parallel to it, with four short taxiways connecting the two. While waiting for Gran Canaria airport to reopen, the diverted airplanes took up so much space that they were having to park on the long taxiway, making it unavailable for the purpose of taxiing. Instead, departing aircraft needed to taxi along the runway to position themselves for takeoff, a procedure known as a back taxi or backtrack.^[4]

The authorities reopened Gran Canaria airport once the bomb threat had been contained. The Pan Am plane was ready to depart from Tenerife, but access to the runway was being obstructed by the KLM plane and a refueling vehicle; the KLM captain had decided to fully refuel at Los Rodeos instead of Las Palmas, apparently to save time. The Pan Am aircraft was unable to maneuver around the refueling KLM, in order to reach the runway for takeoff, due to a lack of safe clearance between the two planes, which was just 3.7 meters (12 ft). The refueling took about 35 minutes, after which the passengers were brought back to the aircraft. The search for a missing Dutch family of four, who had not returned to the waiting KLM plane, delayed the flight even further. A tour guide had chosen not to reboard for the flight to Las Palmas, because she lived on Tenerife and thought it impractical to fly to Gran Canaria only to return to Tenerife the next day. She was therefore not on the KLM plane when the accident happened, and she would be the only survivor of those who flew from Amsterdam to Tenerife on Flight 4805.

The tower instructed the KLM to taxi down the entire length of the runway and then make a 180-degree turn to get into takeoff position.^[16] While the KLM was back-taxiing on the runway, the controller asked the flight crew to report when it was ready to copy the ATC clearance. Because the flight crew was performing the checklist, copying this clearance was postponed until the aircraft was in takeoff position on Runway 30.

Shortly afterward, the Pan Am was instructed to follow the KLM down the same runway, exit it by taking the third exit on their left and then use the parallel taxiway. Initially, the crew was unclear as to whether the controller had told them to take the first or third exit. The crew asked for clarification and the controller responded emphatically by replying: "The third one, sir; one, two, three; third, third one." The crew began the taxi and proceeded to identify the unmarked taxiways using an airport diagram as they reached the taxiways.

The tower instructed the KLM to taxi down the entire length of the runway and then make a 180-degree turn to get into takeoff position.^[16] While the KLM was back-taxiing on the runway, the controller asked the flight crew to report when it was ready to copy the ATC clearance. Because the flight crew was performing the checklist, copying this clearance was postponed until the aircraft was in takeoff position on Runway 30.

Shortly afterward, the Pan Am was instructed to follow the KLM down the same runway, exit it by taking the third exit on their left and then use the parallel taxiway. Initially, the crew was unclear as to whether the controller had told them to take the first or third exit. The crew asked for clarification and the controller responded emphatically by replying: "The third one, sir; one, two, three; third, third one." The crew began the taxi and proceeded to identify the unmarked taxiways using an airport diagram as they reached them.

The crew successfully identified the first two taxiways (C-1 and C-2), but their discussion in the cockpit never indicated that they had sighted the third taxiway (C-3), which they had been instructed to use. There were no markings or signs to identify the runway exits and they were in conditions of poor visibility. The Pan Am crew appeared to remain unsure of their position on the runway until the collision, which occurred near the intersection with the fourth taxiway (C-4).

The pilots   in the cockpit never indicated that they had sighted the third taxiway (C-3), which they had been instructed to use. There were no markings or signs to identify the runway exits and they were in conditions of poor visibility. The Pan Am crew appeared to remain unsure of their position on the runway until the collision, which occurred near the intersection with the fourth taxiway (C-4).

The angle of the third taxiway would have required the plane to perform a 148-degree turn, which would lead back toward the still-crowded main apron. At the end of C-3, the Pan Am would have to make another 148-degree turn, in order to continue taxiing towards the start of the runway, similar to a mirrored letter "Z". Taxiway C-4 would have required two 35-degree-turns. A study carried out by the Air Line Pilots Association (ALPA) after the accident concluded that making the second 148-degree turn at the end of taxiway C-3 would have been "a practical impossibility."^[21] The official report from the Spanish authorities explains that the controller instructed the Pan Am aircraft to use the third taxiway because this was the earliest exit that they could take to reach the unobstructed section of the parallel taxiway.

Los Rodeos airport is at 633 meters (2,077 ft) above sea level, which gives rise to cloud behavior that differs from that at many other airports. Clouds at 600 m (2,000 ft) above ground level at the nearby coast are at ground level at Los Rodeos. Drifting clouds of different densities cause wildly varying visibilities, from unhindered at one moment to below the minimums the next. The collision took place in a high-density cloud.

The Pan Am crew found themselves in poor and rapidly deteriorating visibility almost as soon as they entered the runway. According to the ALPA report, as the Pan Am aircraft taxied to the runway, the visibility was about 500 m (1,600 ft). Shortly after they turned onto the runway it decreased to less than 100 metres (330 ft)

Meanwhile, the KLM plane was still in good visibility, but with clouds blowing down the runway towards them, the aircraft completed its 180-degree turn in relatively clear weather and lined up on Runway 30. The next cloud was 900 netres (3,000 ft) down the runway and moving towards the aircraft at about 12 knots (14 mph; 22 km/h.

Immediately after lining up, the KLM captain advanced the throttles and the aircraft started to move forward. First officer Meurs advised him that ATC clearance had not yet been given, and captain Veldhuyzen van Zanten responded: "No, I know that. Go ahead, ask." Meurs then radioed the tower that they were "ready for takeoff" and "waiting for our ATC clearance". The KLM crew then received instructions that specified the route that the aircraft was to follow after takeoff. The instructions used the word "takeoff," but did not include an explicit statement that they were cleared for takeoff.

Captain Meurs read the flight clearance back to the controller, completing the readback with the statement: "We are now at takeoff."  Captain Veldhuyzen van Zanten interrupted the co-pilot's read-back with the comment, "We're going.”

The air controller, who could not see the runway due to the fog, initially responded with "OK" (terminology that is nonstandard), which reinforced the KLM captain's misinterpretation that they had takeoff clearance. The controller's response of "OK" to the co-pilot's nonstandard statement that they were "now at takeoff" was likely due to his misinterpretation that they were in takeoff position and ready to begin the roll when takeoff clearance was received, but not in the process of taking off. The controller then immediately added "stand by for takeoff, I will call you", indicating that he had not intended the clearance to be interpreted as a takeoff clearance.

A simultaneous radio call from the Pan Am crew caused mutual interference on the radio frequency, which was audible in the KLM cockpit as a 3-second-long shrill sound (or heterodyne). This caused the KLM crew to miss the crucial latter portion of the tower's response. The Pan Am crew's transmission was "We're still taxiing down the runway, the Clipper 1736!" This message was also blocked by the interference and inaudible to the KLM crew. Either message, if heard in the KLM cockpit, would have alerted the crew to the situation and given them time to abort the takeoff attempt.^.  

Due to the fog, neither crew was able to see the other plane on the runway ahead of them. In addition, neither of the aircraft could be seen from the control tower, and the airport was not equipped with ground radar.

After the KLM plane had started its takeoff roll, the tower instructed the Pan Am crew to "report when runway clear." The Pan Am crew replied: "OK, will report when we're clear." On hearing this, the KLM flight engineer expressed his concern about the Pan Am not being clear of the runway by asking the pilots in his own cockpit, "Is he not clear, that Pan American?" Veldhuyzen van Zanten emphatically replied "Oh, yes" and continued with the takeoff not knowing that the other plane was b his way. The inevitable collision was seconds from the oncoming plane collision.

Aside from the mistake made by the plane heading towards the parked plane, there were other mistakes to consider. The controller in the tower should not have just said “OK’ as it wasn’t sufficient enough for the pilot to fully understand the meaning of the instructions given. Further no airplane should move down a runway in a  fog. Further it shouldn’t take off unless not only the runway is clear, but at least  a  couple of thousand feet ahead of the plane is  also clear so that the pilot can be sure that another plane is not to directly ahead of him in the air.