Investigators are now hoping other pilots in the area may be able to help answer their questions.
"We invite anyone around the area, not necessarily who saw it, but heard it on the radio, or if they can step forward," said Maja Smith with National Transportation Safety Board.
An official with the NTSB says they're still in the early phases of their investigation into the crash killed 76-year-old Joe Kulbeth, and 28-year-old Sam Chimienti.
The agency recovered the wreckage, and will now look into the pilot's certification, environmental factors, and if there was an issue with the plane's engine.
"We'll be able to tell if it was operating, what range it was operating, if it was it malfunctioning," Smith said. "So it will close those doors making sure there was nothing mechanically wrong."
Pilots at the Madera Municipal Airport told Action News that Joe was practicing various skills with Sam, and another says they were simulating an engine failure.
Fresno Flight owner and instructor Marty Beville says he's still stunned at the loss.
"Whatever it was, it must've been pretty fast because Joe is a great pilot," he said. "If there was something that could've been fixed, he could've fixed it."
He says Joe was well-known in the flight community and was very active with light sport aircraft, which are smaller and have different requirements.
You can fly with a drivers license in some of the light sport categories, you don't need an FAA medical to fly these lightweight aircraft," Beville said.
The NTSB says they'll have a preliminary report in at least 10 days. Federal investigators say it could take up to 2 years for them to release an official probable cause for the crash.
Madera Municap is an uncontrolled airport, and federal investigators say that means pilots are required to make radio calls, however, they will be looking to see if there were any radio communications.
At this point, Madera County hasn't released an official cause of death for either victim.