A crew formed by seven aviation lovers led by Captain Arturo Prom, were available at the very early hours of August 31, 1986 to board their plane at the International Airport of Mexico City (AICM); it was a McDonnell Douglas DC-9-32 from the Aeroméxico airline that would make flight AM498 to Los Angeles International, with some stops.

The aircraft wore the colors of the time, a very distinctive livery in shades of orange, silver and with the eagle knight and white letters; It was the “Hermosillo” a DC-9-32 license plate XA-JED that was built by the manufacturer McDonnell Douglas in 1969.

At 11:44 local time, Captain Arturo Prom made the first contact with the controller Walter White, who was at the head of the approach screen of the Los Angeles Airport and gave instructions to flight AM498 for a descent to 7,000 feet. of altitude and heading 320, to intercept the final ILS to runway 25L (left).

At the same time, White, tried to drive away a Grumman Tiger identified as 66R, traffic that should not be in said airspace. The controller instructs both aircraft, the Aeromexico to reduce speed and maintain a waiting pattern and the Tiger to leave the airspace.

The instructions had paid off, the DC-9 continued its approach, hoping to continue its descent after being de-programmed from the pattern. Unfortunately, another airplane flying under visual conditions (VFR), a Piper PA-28-181 Cherokee license plate N4891F, mistakenly entered the trajectory of Aeromexico’s DC-9, in what amounts to a restricted airspace for aircraft in visual conditions and said size.

Both aircraft did not have the system of TCAS (Traffic Alert and Collision Avoidance System) alert, nowadays indispensable to know the traffic that fly around us and protect us from a possible collision.

At 11:52 local time, both aircraft were in the sky, the Piper PA-28 hit the management of the DC-9; structure that houses surfaces of primary controls such as the rudder and elevators, which cause the aircraft to make yaws and pitches, critical movements for any aircraft.

The management of the DC-9 was started after the impact, leaving the crew of the Captain Prom and his first Officer Hector Valencia, an ungovernable aircraft, not to mention the structural condition of Piper that was severely damaged; two aircraft without control, in loss and with time counted.

The DC-9 hit the ground in the suburb of Cerritos; Fifteen people on earth died more than 64 souls on board. The remains of the Piper also hit the ground, inside the captain William Kramer, wife and daughter who were heading to Big Bear Lake, coming from the Zamperini Field airfield, also lost their lives.

This is one of the worst accidents that today the Aeromexico Group, its crews, family members and other members of the aeronautical community remember as one of the worst in history; a fact that should not have occurred and that would expose several flaws in the procedures and lack of anti-collision systems on board aircraft (TCAS).

The chain of errors -especially of procedures- generated that will be made in future flights, a better separation of conflicting traffics, and a greater vigilance on the part of the controllers and their radars in the restricted air spaces for some aircraft in the United States.

In the suburb of Cerritos, in the Sculptural Garden, a monument was constructed that remembers with its names all the victims of the accident.

Source: Transponder1200