Crash of the Century – Tenerife Airport Disaster
Category : Air Crash
Crash of the Century – Tenerife Airport Disaster
By Ofonime Essien
- Date – March 27, 1977
- Type – Pilot error, runway incursion, poor weather conditions, limitations and failures in communication
- Site – Los Rodeos Airport (now Tenerife North Airport) Tenerife, Canary Islands, Spain
- Total fatalities – 583
- Total survivors – 61
The Tenerife Airport Disaster occurred at just before 5:07pm on 27 March 1977. Despite the terrible loss of life as a result of the terrorist attacks on the Twin Towers in 2001, the tragic accident at Los Rodeos still retains the dubious title of having the highest number of fatalities (excluding those on the ground) of any single incident in aviation history.
There were two aircraft involved in this Tenerife Airport disaster, a Pan American World Airways and a KLM Royal Dutch Airlines, both of them Boeing 747s. In 1977, Los Rodeos Airport only had one runway and the two aircraft found themselves taxiing along it in opposite directions, on a collision course.
Both aeroplanes were bound for Las Palmas, on the island of Gran Canaria. It was only as they were approaching the Canary Islands that events began that would ultimately lead to the tragedy.
At 1:15pm on the day of the accident, a small terrorist bomb exploded in the terminal building of Las Palmas Airport. There had been a warning, so there were a few injuries, but no deaths. A phone call claimed responsibility and told of a second bomb. The airport authorities had no choice but to temporarily close the airport.
The Pan Am and the KLM aircraft were both told to divert to the nearest alternative airport, which was Los Rodeos. At least three other large, long-haul planes were directed there too.
Los Rodeos Airport was ill-equipped to deal with so many large aircraft. As mentioned earlier, it had only one runway, plus one main taxiway, running parallel to it. There were also several smaller taxiways connected to this main one. With so many large planes to accommodate, it was necessary to park them on the main taxiway, resulting in planes about to take off having to taxi into position using the actual runway.
Whilst on the ground, the captain of the KLM flight decided to refuel, to save time. This decision meant that the aircraft was fully fueled when the Tenerife Airport disaster occurred – and the resulting conflagration was that much more terrible.
Eventually, word came through that Las Palmas Airport had been reopened, so the KLM plane was cleared by the control tower and told to back-taxi to the end of the single runway, then make a 180 turn (a difficult manoeuver in such a narrow space). The aircraft’s crew were asked to acknowledge this clearance, but, because they were performing their pre-flight check, this was never made until the plane was in take-off position. Meanwhile, low clouds had drifted in, resulting in a fog that limited visibility to just under 1000 feet.
Next, the Pan Am flight was instructed to back-taxi along the same runway, then leave it at the third exit, taking it onto the main taxiway. The captain asked for a repeat of the exit number and was told “The third one, sir, one, two, three, third. The third one”. The aircraft began its slow taxi, with the crew using a map of the airport to find the required exit. Remember, it was foggy by this time. It appears that the crew never managed to identify the correct exit 3. This is reflected in the fact that the imminent collision eventually happened near the fourth exit.
It was at about this time that there appear to have been misunderstandings in communication between the planes and the control tower. The captain of the KLM flight instructed his co-pilot to report that they were ready for take-off and to request clearance. The control tower then gave a clearance which specified the aircraft’s departure route and gave instructions of what to do after take-off. It was not a specific clearance for actual take-off.
The co-pilot’s reply was “We’re now at take-off”, to which the control tower replied “OK”. It appears that the flight crew meant that they were actually beginning their take-off, while the controller took it to mean they were in take-off position, awaiting final clearance. He added, “Stand by for take-off, I will call you”.
At that point in events leading to the Tenerife Airport disaster, there occurred the most unfortunate coincidence of all. A simultaneous radio call from the Pan Am flight, saying that they had not finished taxiing and were still on the runway, had the effect of causing radio interference, so the control tower’s last few words were not heard by the KLM captain. The crucial information of the Pan Am flight’s position was also lost. If both these messages had been heard, the KLM flight would have been able to abort its take-off.
Because of the fog, the aircraft could not see each other and neither could be viewed from the control tower. Also, Los Rodeos Airport wasn’t equipped with ground radar. The tower asked the Pan Am flight to report when it was clear of the runway. Its captain replied, “OK, we’ll report when we’re clear”. On hearing this, the flight engineer on the KLM flight expressed concern about the position of the other aircraft. The KLM captain, however, seemed positive he had been given clearance for take-off and continued down the runway.
As the two planes approached one another, their respective crews eventually saw the other plane’s landing lights through the fog. The Pan Am captain applied full power and attempted to veer sharply onto the fourth exit. The KLM captain attempted a steep climb, scraping the planes’s tail along the runway for some 65 feet. It left the ground, but its underside struck the Pam Am plane’s upper fuselage, ripping it apart. The KLM plane stalled and came down some 500 feet further on, then slid a further 1000 feet.
The loss of life from the Tenerife Airport disaster was horrendous. From the KLM flight, all 234 passengers and 14 crew perished. 326 passengers and 9 crew on the Pan Am flight died, primarily due to the spilt fuel igniting and exploding. 56 passengers and 5 crew from this flight survived. Some people who had survived the crash and were out on the runway were killed by shrapnel flying from the 747’s engines, which were still running after the impact. Firefighters initially rushed to the KLM aircraft, believing, due to the thick fog, that there was only one plane involved. Ironically, this was the plane with no survivors.
There followed an extensive investigation into the cause of the Tenerife Airport Disaster by a team of 70 investigators. Their conclusions were that the main reasons such a catastrophe was allowed to happen were:
- The KLM flight started its take-off without proper clearance.
- The Pan Am flight missed the third exit it was told to use, instead carrying on towards exit four.
- The loss of two crucial radio messages, due to their being broadcast as exactly the same time and causing cross-interference, resulting in meaningless radio hiss-and-crackle.
- Use of non-standard responses, such as “OK”.
- The airport being forced to accommodate a number of large aircraft, way beyond its capacity.
Changes made to airport procedures as a result of the Tenerife Airport Disaster echoed around the word.
Aviation authorities now insisted on the use of standard phrases, as opposed to such colloquialisms as “OK” in radio responses. The phrase “take-off” was not to be used until the actual take-off was due to take place. Instead, control towers and aircrew should refer to “departure”.
The following year (1978), Tenerife’s second airport was inaugurated. Reina Sofia Airport was much bigger and took over international flights. Los Rodeos was relegated to servicing only domestic and inter-island flights, such as its size permitted.
Ground radar was installed at Los Rodeos.
In 2002, a new terminal was opened at Los Rodeos and the airport regained its international status.