Lembit was born in Northern Ireland, to Estonian parents, receiving his schooling in Belfast and his degree in Bristol. He first became actively interested in aviation at the age of 6, when he first saw Concorde at Heathrow Airport. It was then he resolved to learn to fly, an ambition he subsequently achieved 17 years later, at Leicester Airport. Since then, Lembit has actively developed his licence and now holds an PPL, plus a Night rating, Instrument Meteorological Conditions Rating, a Multi Engine Piston rating, and half the examinations for a UK Instrument Rating.

Lembit's main interest as a pilot is light twins, but he has also become actively involved in the world of air charter work. His commercial involvement is through Doncaster based Sovereign Air, and through the air brokerage West European Air Services. However, Lembit's main contribution to aviation is as a aeronautical parliamentarian. Together with a handful of flying colleagues, he is a founder member of the Parliamentary Aviation Group, which seeks to stand up for the interests of General Aviation in all its forms in the UK. He is committed to opposing senseless new rules, and promotes the case for a risk management strategy, based on data rather than assumptions.

Lembit believes the future of General Aviation is best assured by a constructive partnership between the sector and the CAA, as well as with EASA. For these reasons he has worked to develop formal links with both bodies. Lembit also campaigns for a "single voice" for British and European General Aviation, to strengthen the strategic consistency which underpins the lobbying work which is necessary to protect private flying. He is a regular contributor to Flight Training News and also in Parliament, when the opportunity to raise the interests of the General Aviation sector present themselves.