Complex sentence: The Air Ambulance Service (TAAS) is a registered charity in the UK that manages three air ambulance appeal charities: Derbyshire, Leicestershire & Rutland Air Ambulance and Warwickshire & Northamptonshire Air Ambulance, and The Children's Air Ambulance.
Split into simpler sentences: The Air Ambulance Service is a registered charity in the UK that manages three air ambulance appeal charities. These are Derbyshire, Leicestershire & Rutland Air Ambulance and Warwickshire & Northamptonshire Air Ambulance, and The Children's Air Ambulance.