More than 25 aircraft involved in search for missing Queensland pilot

The search for a missing Queensland pilot has been expanded to include 21 helicopters and five planes.

Avid amateur pilot Rob Pavan was last seen in a Jabiru twin-seater plane he built himself at around 9.30am yesterday at Gympie Airstrip.

A full-scale search has now been launched for Mr Pavan who took off from Gympie in the home-made light aircraft to travel to a friend's 60th birthday party at Dixalea, west of Gladstone, only 90 minutes away.

The widespread search now covers 6200 square kilometres.

Friends said Mr Pavan has built at least 12 aircraft, including the Jabiru he was travelling in.

Pilots spent today scouring terrain north of Gympie, which AMSA Search and Rescue spokeswoman Andrea Hayward-Maher said was "quite mountainous and quite heavily vegetated".

"The crews do have to really take their time while they're searching and ensure they're getting eyes on it very slowly because there is a lot of vegetation down there," she said.

"The weather conditions were a bit tricky yesterday so that might have played a factor."