One plane, which took off from Mangalore Airport, had been flying for about three minutes and was gaining height when the collision happened. It hit the ground within seconds near the Seymour-Avenel Road just south of the airport. That plane was run by Moorabbin Aviation Services but based at Mangalore. Loading Replay Replay video Play video Play video The other plane, a Beechcraft Travel Air and operated by the Peninsula Aero Club, took off from Tyabb, on the Mornington Peninsula. It continued flying north after the collision for about two kilometres before slamming into the ground near Lambing Gully Road in Avenel. The plane from Tyabb was heading toward the Mangalore Airport. Authorities believe the plane was either planning on landing or performing a practice approach without actually touching the tarmac.

Mangalore Airport does not have a traffic controller, and pilots are required to make radio broadcasts on their intention to fly near the airport. Police attended both crash scenes about 11.30am and are investigating the cause of the collision. They say it is too early to know if weather conditions were a factor. Witnesses in a nearby chopper and locals who were in a paddock have spoken to police, with another witness saying she saw a plane “spiralling out of control”. “We’re not sure why both aircraft were on the same trajectory, or why they were in that area,” Victoria Police Inspector Peter Koger said.

“One plane almost certainly crashed immediately and the other plane crashed about two kilometres north from here and both were extensively damaged prior to colliding with the ground. “It's a big tragedy for both families ... it's very upsetting for everyone including emergency services.” Police are investigating the cause of the fatal mid-air collision. Credit:Nine News Families of the victims and the owners of the planes were being notified of the crash on Wednesday afternoon. The two planes were intending to fly under what is known as instrument flight rules (IFR), where automatic systems guide the flight and pilots do not need to be able to see the surface in order to navigate.

Under IFR, planes can fly through clouds. It is not clear whether the planes were flying under IFR when the incident occurred. Both planes had clearance to fly near Mangalore Airport, which has an aviation-training facility and is popular with recreational pilots. A spokesman for the Civil Aviation Safety Authority said one of the aircraft was a Piper Seminole, registered to the flight school Moorabbin Aviation Services. The second aircraft was a Beechcraft Travel Air registered to a private owner at Tyabb.

Crash investigators from Melbourne, Sydney and Brisbane are being deployed to the scene. The investigators, from the Australian Transport Safety Bureau, will examine the wreckage, all recorded flight data and any weather conditions that may have affected flying conditions. One of the planes crashed in woodland. Credit:Nine The ATSB is appealing for any witnesses who saw the planes in flight or who have dash-cam footage to contact authorities. CASA and the Australian Transport Safety Bureau have been notified, and police will prepare a report for the Coroner.

All southbound lanes on the Hume Freeway have been closed near Avenel. Local Joanne Dwyer, who lives just south of Avenel, said she was driving to Seymour between 11am and 11.30am and saw a plane in difficulty. "I was driving up the Hume towards Seymour and there's a bit of a rise and I see this plane doing what I would have called a death roll," she said. "Planes do practice manoeuvres around here all the time but I thought that seems to be going a bit lower than normal." She said it looked like it was "spiralling out of control in the distance".