Pilot and passenger die in NSW crash

A Victorian couple believed to be in their 60s have died in a light plane crash in mid-west NSW.

The pilot, with 40 years flying experience, and his wife left were heading north to Mudgee on Sunday.

As they approached to land at the town's airport, the plane's only engine was spluttering. The two-seater crashed on its side just metres from the runway, witnesses told the Seven Network.

"It just dropped, just like a rock, straight down," witness Grant Willetts said.

The pilots of the other three planes travelling with the couple landed safely.

"This is tragic. Not only are the people they were travelling with would be devastated (sic) but it impacts on a lot of, lot of people," Detective Inspector Cameron Whiteside said.

The couple from Pakenham died at the scene.

The Australian Transport Safety Bureau has joined an investigation by police and specialist forensic officers.

A crime scene has been established.