Complex sentence: New European microlight helicopter regulations in 2011 allowed production to start and the company produced the H2 and later the H3 which became the sole product in the mid 2010s, superseding the H2 in production.
Split into simpler sentences: New European microlight helicopter regulations in 2011 allowed production to start and the company produced the H2 and later the H3. The H3 became the sole product in the mid 2010s, superseding the H2 in production.