The National Transportation Safety Board (NTSB) released its preliminary findings into what caused a Piper PA-31T (Cheyenne) to crash shortly after take off from Fort Lauderdale Executive Airport on March 16.

Steven Waller, 65, of Deerfield Beach, Wallis "Wally" Watson, 66, of Boca Raton, and Kevin Watson, 30, of Pompano Beach, were killed. Waller was the pilot.

According to the Federal Aviation Administration, Waller was taking the father and son on a test flight before the plane was shipped to a customer in Columbia.

The owner stated that the airplane had undergone engine ground checks during the four days prior to the accident, according to the NTSB. He was not aware of any maintenance issues with the airframe or engines, which underwent detailed inspections at the time of the purchase.

The airplane took off and was expected to turn left for a northwest departure, but instead witnesses reported seeing it make a steep right turn back toward the airport.

Waller transmitted that he was experiencing an emergency but didn't explain what happened.

Another pilot waiting on the runway said he saw the plane have difficulty climbing, appear to stall, roll to the right about 90 degrees, and fall straight down toward the ground.

The plane hit several parked vehicles and a boat, sending flames 50 feet in the air. All but the right wingtip fuel tank was consumed in the fire, said the NTSB.

"The right landing gear was found retracted in its respective gear well, while the structure around the nose and left main landing gears was compromised," read the report. "The left and right flap actuator jackscrews indicated the flaps were in the retracted position. The airplane's stability augmentation system control arm was observed in the up (airplane stalled) position. It was noted that internal damage to both engines was consistent with rotation somewhere between the low to mid-range power setting, with more pronounced damage observed to the left engine. The three-bladed right propeller assembly did not display any significant evidence of twisting or rotational damage, while the left propeller assembly displayed evidence of twisting and rotational damage."

On Wednesday, police released 911 calls made about the crash.

The most recent documented inspections on the plane were performed on Jan. 31, 2012, according to maintenance logbooks.