Mexican Air Force - Fuerza Aérea Mexicana

Crashed in unknown circumstances into the Pacific Ocean, off the Baja California coast. No trace of the aircraft nor the eight crew members was found. Local medias stated that the aircraft was carrying a load of seven thousand pounds of live lobsters, which would suggest that the aircraft could also have been operated by a civil airline, not the Mexican Air Force.
Source: ASN

Crashed shortly after takeoff from Guadalajara AFB, killing all four occupants.

Shortly after takeoff from Puebla-Hermanos Serdán-Huejotzingo Airport, while in initial climb, the crew informed ground that the right engine malfunctioned and elected to return. Shortly later, the aircraft stalled and crashed few km from the airport. All 21 occupants were killed.

The crew started the takeoff procedure by night and in foggy conditions. Shortly after rotation, the twin engine aircraft failed to climb properly, hit a perimeter fence and crashed in flames in a field located near the Balbuena District. Two crew members and seven passengers were killed, among them the Ambassador of Soviet Union in Mexico, Constantino Oumansky who was travelling to Costa Rica with his wife and his staff. Both survivors were the flight engineer Manuel Noble Mercado and the passenger Marión Troyinsky.
Crew:
Cpt Roque Velazco Cerón, pilot, †
Cpt Hilario Romero Martínez, pilot, †
Manuel Noble Mercado, flight engineer.

The pilot was completing a local training flight out from Mexico City Airport. In unknown circumstances, the single engine airplane registered 13 and named Chiapas collided with a second DH.4B of the Mexican Air Force that was engaged in a same type of mission. Registered 11 and named Tabasco, the second aircraft was also carrying one pilot. Following the collision, both airplanes dove into the ground and crashed in the district of Jardín Balbuena, southwest of the airfield. Both aircraft were destroyed and both pilots were killed.

The pilot was completing a local training flight out from Mexico City Airport. In unknown circumstances, the single engine airplane registered 11 and named Tabasco collided with a second DH.4B of the Mexican Air Force that was engaged in a same type of mission. Registered 13 and named Chiapas, the second aircraft was also carrying one pilot. Following the collision, both airplanes dove into the ground and crashed in the district of Jardín Balbuena, southwest of the airfield. Both aircraft were destroyed and both pilots were killed.

Crashed in unknown circumstances in El Rosario, Mexico City, killing both crew members Puflet and Bornio.