A soldier badly injured in a fatal Army truck crash has told a Sydney court the driver was "deliberately" aiming for potholes and trying to get the vehicle to slide around bends at Holsworthy Army Barracks.

Alexander Gall, 26, is standing trial in the District Court accused of seven serious offences including dangerous driving causing death.

He was driving a six-tonne Army personnel vehicle known as a Unimog with 18 people on board back to base after a training exercise in October 2012 when it rolled, killing Sapper Jordan Penpraze and seriously injuring six other people including Sapper Dylan Williams.

Sapper Williams told the jury he could "feel" that Gall was aiming at potholes in the road and driving recklessly.

He said he also saw the vehicle's speedometer hit 80 kilometres per hour in an area limited to 40kph.

Eighteen soldiers were thrown from the truck when it rolled at Sydney's Holsworthy Army Barracks. ( ABC TV )

Sapper Williams said Gall was making the large truck "slide" around a corner.

"Gall was trying to deliberately get the vehicle to drift," he said.

"I could see him, he was excited, he was happy, then we went around the corner — we started fishtailing. He started to panic."

Sapper Jordan Penpraze died from injuries sustained in the truck accident. ( Australian Defence Force )

Under cross examination he denied that his story had changed since being interviewed in the days after the accident and since giving a statement to a military tribunal.

Sapper Jarred Robinson was another of the 15 soldiers riding in the back of the Unimog driven by Gall, and he told the jury he felt they were going "way too fast".

"I know people were banging on the cabin of the truck, I'm pretty sure I heard them say 'slow down'. It was a general consensus we were going too fast," he said.

Sapper Robinson also denied changing the account he had given crash investigators.

Earlier, the commanding officer of the training exercise, Lieutenant Sean Mulligan told the jury Gall was not given a safety briefing about speed limits.

Under questioning from Gall's defence barrister, he also said he did not know Gall only held a civilian L-plate licence and that he had only 14 hours experience driving the Unimog vehicle.

The trial continues.