 This contract was ended in early 2014, however YAS has the ability to call on private companies and St John Ambulance to provide cover in times of extreme need, and a long term contract is held with St John to provide fully crewed ambulances to YAS for emergency and non-emergency work.YAS employs 4,679 staff, who together with 1,055 volunteers, provide a vital 24-hour emergency and healthcare service.The largest proportion of staff, over 62%, are employed in operational patient-facing roles including Accident and Emergency, Patient Transport Service, NHS 111, Hazardous Area Response Team, Yorkshire Air Ambulance paramedics, Emergency Operations Centre, Resilience and Special Services, Private and Events, Resource and Embrace paediatric and neonatal transport service.