David Johnathan Holmyard, 26, formerly of Evandale, hung his head in the dock in the Supreme Court on Monday when the Crown's statement of facts was read.

He entered a late guilty plea to motor manslaughter on the second day of his trial in Launceston last week.

Crown prosecutor Linda Mason told the court that the crash killed motorist Maureen Ann Flanagan when she was just outside her home on Evandale Road at Western Junction, on the night of November 7, 2014.

Ms Mason said Holmyard had been drinking alcohol at an Evandale hotel and his capacity to drive was affected by the alcohol as well as cannabis and methylamphetamine.

She said Holmyard evaded police who tried to intercept him for speeding and a broken headlight, and while on the wrong side of the road he accelerated to 174 km/h and his car remained airborne for 21 metres.

Ms Mason said Holmyard made no effort to brake or avoid the crash and his speed at the point of impact was 170 km/h.

She also read three victim impact statements from the Flanagan family to the court.

Defence counsel Mark Doyle requested an adjournment of his plea in mitigation to allow the preparation of a pre-sentence report through Forensic Mental Health Services.

Mr Doyle said Holmyard had been seeing a psychologist and had been diagnosed with post-traumatic stress disorder.

Justice Robert Pearce ordered a report from the chief forensic psychiatrist and adjourned Holmyard's matter for mention to February 1 next year.