FLAGSTAFF, Ariz., June 30 (UPI) -- Officials began their investigation Monday into what caused a in-flight collision between two medical helicopters in northern Arizona that killed six people.

FLAGSTAFF, Ariz., June 29 (UPI) -- Seven people were killed Sunday afternoon when two medical helicopters collided in flight in Flagstaff, Ariz., a government official said.

SANTA MONICA, Calif., May 19 (UPI) -- The Federal Aviation Administration is battling a California city over its unprecedented attempt to ban certain high-performance jets for safety reasons.

LOS ANGELES, April 13 (UPI) -- A small plane crashed into two houses near Los Angeles' Compton Airport, injuring at least five people, officials said.

LOS ANGELES, April 12 (UPI) -- At least four people were injured Saturday when a small plane crashed into two houses not far from Compton Airport near Los Angeles Saturday, police said.

HONOLULU, Feb. 20 (UPI) -- A pair of go! airline pilots are under federal investigation on suspicion of falling asleep during an inter-island flight between Honolulu and Hilo, Hawaii.

SACRAMENTO, Jan. 25 (UPI) -- The labor union representing U.S. air traffic controllers says staffing shortages at air towers across the country is endangering public safety.

SACRAMENTO, Dec. 13 (UPI) -- A Delta Airlines passenger jet made an emergency landing Wednesday, shortly after hitting a bird while taking off from a California airport.

LOS ANGELES, Nov. 6 (UPI) -- Two people were killed Tuesday when a twin-engine airplane crashed shortly after lifting off from the Chino, Calif., Airport.