Aeroméxico Flight 498
Aeroméxico Flight 498, registration XA-JED, was a Douglas DC-9-32 en route from Mexico City, Mexico to Los Angeles International Airport, Los Angeles, California (with stops in Guadalajara, Loreto, and Tijuana) on August 31, 1986. N4891F, callsign Piper 4891 Foxtrot, was a privately-operated Piper PA-28-181 Archer owned by the Kramer family en route from Torrance to Big Bear City, California. The two aircraft collided in mid-air over Cerritos, California, killing all 67 aboard both aircraft and 15 people on the ground. In addition, 8 persons on the ground sustained minor injuries from the crash  (8/115).
At approximately 11:46 AM, Flight 498 began its descent into Los Angeles with 58 passengers and six crew members aboard. Minutes earlier, N4891F, carrying a pilot and two passengers, departed Torrance. At 11:52 AM, the Piper's engine collided with the left horizontal stabilizer of the DC-9; this sheared off the top of the Piper's cockpit, killing the pilot and two passengers.
The DC-9 inverted and fell to the earth in a residential neighborhood at Holmes Avenue and Ashworth Place in Cerritos , killing 15 on the ground and all 64 passengers and crew. The impact and fire destroyed five houses and damaged seven houses. A fire sparked by the crash contributed significantly to the damage. The heavily damaged Piper fell into Cerritos Elementary School's playground. When the air traffic controller assigned to Flight 498 could not find the flight, he called American Airlines Flight 333, incoming into Los Angeles, for assistance. The pilot on AA333 replied said that he saw a smokescreen, indicating that 498 crashed.
The National Transportation Safety Board investigation found that N4891F had deviated into the LAX Terminal Control Area. It was out of radio contact with air traffic control, which had been distracted by another flight entering the area. Moreover, the Piper was not equipped with a Mode C transponder indicating its altitude, and LAX had not been equipped with automatic warning systems. Finally, neither pilot had sighted the other aircraft, even though they were in visual range. When an autopsy revealed significant arterial blockage in the heart of the Piper's pilot, there was public speculation that he had suffered a heart attack, causing incapacitation and contributing to the collision; however, further forensic evidence discounted this, and error on the part of the Piper pilot was determined to be the main contributing factor to the collision.
As a result of this accident and other near mid-air collisions (NMAC) in terminal control areas, the Federal Aviation Administration required all commercial aircraft be equipped with traffic alert and collision avoidance systems (TCAS), and required that light aircraft operating in dense airspaces be equipped with "Mode-C" transponders that could report three-dimensional position. 
As a result of the incident, a jury ruled that the airline had no fault. The jury said that Kramer and the FAA each acted equally negligent and held equal responsibility. U.S. District Judge David Kenyon agreed with the notion that the FAA shares responsibility.
This crash was featured in an episode of Mayday (Air Crash Investigation, Air Emergency) titled "Out of Sight" in the original version and "Collision over LA" in the Air Crash Investigation version.
NTSB drawing portraying approximate point of impact
- ^ "Collision in the "Birdcage"," TIME
- ^ "Aircraft Collision Over Los Angeles Suburb," (diagram) Daily Herald (Chicago), September 2, 1986, p6
- ^ a b "Out of Sight," Mayday
- ^ Larry Gerber, AP, "1986 Cerritos crash changed the way we fly," The Intelligencer Record (Doylestown, Pa.), September 1, 1996, p A-13
- ^ "Jury divides blame in Aeromexico crash," Houston Chronicle
- California Jet Crash Led to Sweeping Changes The New York Times
- Story Of Cerritos - Chapter 8 (Aeroméxico Flight 498)
- Collision in the "Birdcage"
- "Real Life-Mary Wong Sky Magazine October 2007
- DC 9 Crashes in Cerritos Residential Area.
- Landmark Accidents: Collision Over Cerritos
- Out of Sight - Aeromexico Flight 498