Chris Cowan, Essendon Fields CEO; Victoria Police Superintendent Michael Frewen and ATSB's Chief Commissioner, Greg Hood speak during a media briefing on the investigation into the aircraft accident at Essendon Airport. Picture: Scott Barbour/Getty Images

But an expert has admitted the twin-engine aircraft should have been able to successfully take off even after losing an engine.

The plane hit the Essendon’s Direct Factory Outlet (DFO) shopping complex yesterday morning shortly after take-off, before ploughing into the centre’s carpark.

Revealing the Australian Transport Safety Bureau’s initial findings, chief commissioner Greg Hood this morning said the aircraft should have been able to withstand a single engine failure.

“Modern aircraft are designed to climb out on one engine,” he told a Melbourne press conference.

Mr Hood said the ATSB investigation, led by “four of our finest investigators” was in its early stages and a preliminary report would be handed down within 28 days.

The crash site, burnt and strewn with wreckage, will be handed over for the ATSB but police investigators will continue their work at the site, which takes in the DFO centre’s Homemaker Centre section and rear carpark.

ATSB's Chief Commissioner, Greg Hood, says the plane should have been able to operate with only one engine. Picture: Scott Barbour/Getty ImagesSource:Getty Images

After taking off about 8.30am, the aircraft’s pilot Max Quartermain radioed a mayday to air traffic control before veering left in the direction of the shopping complex, Mr Hood told reporters.

Footage from the location shows serious damage to the building, and the ruins of the burnt aircraft resting in the centre of the destroyed site.

Mr Hood committed to delivering preliminary findings within a month.

“I’d like to think we’d have that out as soon as we possibly can when we have all of the evidence gathered and analysed and when those directly involved parties are able to provide some natural justice by commenting on our draft reports,” he said.

“In 28 days you’ll know the basic facts that we have.”

The crash site at Essendon fields today. Picture: Rob Leeson.Source:News Corp Australia

Mr Hood said investigators already had about 100 witnesses interviews to complete and said dashcam footage from vehicles travelling on the nearby freeway would be integral to the investigation.

The shopping centre and Essendon Airport where the plane took off remain closed as investigators comb through the crash site.

Essendon Fields CEO Chris Cowan, who accompanied Mr Hood at the Melbourne press conference, announced the two operations would be closed until further noticed, and committed to support the investigation.

“Out of respect to the victims of yesterday’s incident the airport is closed to air traffic other than to essential emergency services,” he said.

“The DFO will also remain closed until further notice and an announcement will be made in due course with respect to the DFO.”

Mr Cowan said Essendon Fields’ focus was on assisting investigators as well as its own staff who were shaken by the incident. He thanked emergency services, and commended pilot Max Quartermain who was “well regarded by the Essendon aviation community”.

Pilot Max Quartermain’s record will be considered in the ATSB’s investigation.Source:Supplied

The pilot, who had more than 38 years flying experience, had been required to undergo safety checks by the Civil Aviation Safety Authority whioch he successfully passed, following a “close shave” with another aircraft two years ago.

The incident was under investigation by the ATSB.

Mr Quartermain perished in the crash along with his four passengers US tourists Glenn Garland, Greg De Haven, Russell Munsch and John Washburn.

Russell MunschSource:Supplied

Greg Reynolds De Haven. Picture: FacebookSource:AAP

Glenn Garland. Picture: FacebookSource:Supplied

67-year-old retiree John Washburn.Source:Supplied

The group was on a golfing tour of Australia and New Zealand accompanied by their wives.

Superintendent Mick Frewen said Victoria Police as well as the US embassy were was in “extensive contact” with the victims’ family members and were assisting them through the difficult time.

“With regards to the family, Victoria Police and state government have a key role in maintaining the welfare of the family we’re working closely with the US consulate and multiple victims support services,” he said.

“We’ve got senior ranking reps that are with the family at the moment working through the difficult time with them.”

The victims’ wives are all believed to be in Australia and had opted to take a road trip to the Great Ocean Road rather than accompany the men on their flight.

Supt Frewen said police would also assist in making arrangements with the families regarding the repatriation of the bodies of their loved ones, and other family members who may want to come to Australia.

Dashcam footage will be integral to the investigation. Picture: Team2j/DashcamSource:YouTube