Dan Kneen had an accident at Churchtown on the first lap of the session and died at the scene of the incident.
Dan made his mountain course debut at the Manx Grand Prix in 2008 and won an unprecedented three races – the Junior, the Newcomers C and the Ultra Lightweight MGP Races.
He achieved his first TT podium in last year’s Superstock Race, finishing third in the Superstock TT Race. He has a fastest official lap of 130.347mph which he set in last year’s Superstock Race and recorded a lap of 132.258mph (17:06.994) in last night’s Superbike qualifying session.
He had been riding for Northern Ireland-based team Tyco BMW, and had set his fastest ever lap of the TT Mountain Course on Tuesday night, posting a top speed of 132.2mph.
Team manager Philip Neil said: “We are all numb at the minute if I’m honest. Our thoughts are with Dan’s family and friends. He was a popular, hard-working lad who loved his racing and he will be sorely missed by all who knew him.”