On April 4, 1975 the Vietnam War it’s near the end. US forces launch theBabylift operationthe mass evacuation of children and infants from South Vietnam to the USA and other countries such as France, Australia and Canada. But on April 4th something goes wrong: the first aircraft involved in the operation, a Lockheed C-5 Galaxy with markings 68-0218crashes into the ground while attempting an emergency landing at the Vietnamese Air Force base in Tan Son Nhut. The toll is dramatic: 138 deaths among 314 passengers and crew. This is the plane crash with the highest number of victims involving an American military aircraft.
The Tan Son Nhut disaster
South Vietnam. In April 1975, after ten years of fighting, the United States is on the verge of defeat and the enemy is ever closer to the capital Saigon. On April 4, an unusual load was loaded onto the Lockheed C-5 Galaxy at the military base: dozens of Vietnamese orphans to be brought to safety. The little ones are in the passenger section of the jet, the others on the “downstairs”. Together with them journalists, soldiers and orphanage workers. Five hours behind schedule, Captain Dennis Traynor and co-pilot Tilford Arpa order the cargo hold doors to be closed.
The cargo plane is headed to the Philippines, flight duration two hours and thirty minutes. There the children will be entrusted to adoption associations. At 4.15 pm the Lockheed C-5 Galaxy is flying over the China Sea, but after a few minutes – when it climbs to an altitude of 7 thousand meters – the lock that closes the rear loading ramp gives way, the door opens suddenly and a explosive decompression. The aircraft fills with smoke and fog, debris flies everywhere. Oxygen is scarce, especially in the hold, which is why pilots and passengers resort to masks.
Traynor and Arpa try to regain control of the plane and make a 180 degree turn, heading towards Saigon. But the plane begins to suddenly rise and fall in altitude, but the commander manages to control it by varying the power of the engines. But in the same seconds an even more serious problem emerges: the plane is losing all the electrical fluidnecessary to move the aircraft components. During the sudden opening of the door, the cables leading to the tail were severed, effectively rendering the elevators and the tail rudder useless.
In an extremely difficult situation, eleven kilometers from the airport the pilots manage to begin the approach to runway 25L at Tan Son Nhat, but during a turn they lose control of the aircraft. The vehicle lands in a rice field, travels about 500 meters and leaves the ground again, rising in altitude and flying for another 800 meters. After crossing the Saigon River, it crashes into another rice field, breaking into four parts. The toll is dramatic: 314 occupants 138 dead and 176 survivors. Almost everyone in the hold dies instantly, but Traynor and the other crewmen are safe.
The investigations
The investigations into the Tan Son Nhut disaster begin immediately, even if the investigators have to deal with gangs of South Vietnamese looters who steal valuables, luggage and even plane parts. The investigation conducted by Frank Huskin and colleagues immediately aims to evaluate the track of sabotage: specialized dogs are brought to the accident site, but no traces of explosives or missiles are found.
Why did the cargo hold door break? The work of the investigators revolves around this question, and they decide to bring the remains of the C-5 to America and examine the wreck far from the Vietnamese armed forces. Spotlights on the broken cables that control the elevators: if these are unstable, there is no possibility of directing the plane up or down. And if there’s no elevator control, the plane starts going up and down all the time, the nose goes down and picks up speed and then starts going up again. But the answers are found on the bottom of the China Sea, where the hatch ended up.
The investigators therefore decide to study the trajectory followed by the door: based on the aerodynamic speed and altitude at the moment of decompression, the plane was 45 kilometers from the coast when the accident occurred. The US ships searched for the hatch, but found nothing for many days. In the meantime, the investigators buy the pieces of the plane stolen by the jackals through rewards and try to view the images of the cameras used by the operators on board, but no significant innovations emerge.
The turning point
The disappointment lasts until April 26, when the search in the China Sea bears fruit: the US Navy finds the hold ramp and part of the pressurization door of the plane. And the turning point in the investigation into the Tan Son Nhut disaster is immediate: the investigators discover that three out of seven tailgate locks had not worked properly. In this way the other four functioning ones blew up, thus causing the explosion of the ramp.
Immediately afterwards the investigators identified the cause of this defect: by checking the maintenance records, it emerged that the three malfunctioning locks had been removed and replaced using those of another cargo aircraft. Military aviation in war situations is often short of spare parts and resorts to the practice of removing and replacing parts from non-operational aircraft. But the three locks had not been fitted correctly. Further confirmation comes from the pilots, who explain that they encountered some problems in closing the door before taking off from Saigon.
The consequences
Investigators have identified the cause of the Tan Son Nhut disaster they recommend authorities to intervene in the practice.
The engineers design a nail to insert into the locks in question: if the tailgate is not closed properly the nail will not go into position. Captain Traynor and co-pilot Arpa are awarded the Air Force Cross for their valor, another thirty-seven medals are awarded to crew members or their next of kin.