Copter Crash at El Monte Airport Kills 3 : Aviation: The chopper plummeted shortly after takeoff. A father believes that his son and two friends were aboard the ill-fated craft. NTSB is trying to determine whether mechanical failure or pilot error is at fault.

A helicopter carrying three men crashed and exploded in flames at El Monte Airport on Saturday afternoon, killing everyone on board, officials said.

The R-44 Robertson helicopter apparently took off from the single-runway airport, ascended about 50 feet, then dropped from the sky, said National Transportation Safety Board investigator Scott Erickson.

The NTSB was attempting to determine whether the crash was caused by mechanical failure or pilot error. Officials did not release the names of the victims on board the helicopter.

However, Jack Lovoy of Alhambra told authorities at the scene that his son, Nicholas, 30, had been scheduled to go flying with two friends in a R-44 Robertson, a rare type of helicopter that seats four people.

As Lovoy choked back tears, he asked police if he could see the bodies.

“I want to see my son,” he said. “I’m his father. I have rights.”

Crash investigators agreed to show Lovoy pictures of the scene, but they said that it would be impossible to identify the charred bodies without dental records. Nevertheless, Lovoy said he was certain his son, a resident of La Puente, had been a passenger.

“Why couldn’t I have been in that helicopter?” Lovoy asked. “I’m 60 years old and I’ve lived by life. Why did God have to take my son? This is a disaster.”

Roberta Pryor was cleaning up her back yard, which is next to the runway, when she looked up and saw the helicopter shortly before 2 p.m.

“The next thing we knew we heard ‘boom!’ and they just went down to the ground,” Pryor said. “I started screaming: ‘Oh my God! Oh my God! I think someone might be dying.’ I just stood there and held my heart.”

The helicopter tumbled out of control down the runway. About five explosions followed as it erupted in a cloud of black smoke, she said.

“I was told it was pretty much all over the runway,” El Monte Fire Department dispatcher Richard Fletcher said of the wreckage.

Operations at the airport, which serves mostly single-engine private planes and some helicopters, were restricted after the crash.