At the end of March, London's Air Ambulance passed the 25,000 missions landmark.
London's Air Ambulance service is a charity, and an extraordinary one at that. Processing 4000 emergency calls a day from crises anywhere inside the M25, it's a vital service that really only crosses the radar of Joe Public when it lands in the local park. Like it did in Stoneydown Park in Walthamstow at the weekend.
At the time of writing the London Air Ambulance website is undergoing maintenance, but we've got plenty to share from our archives:
Have a look at our photos from a trip to the London Air Ambulance Helipad atop the Royal London Hospital, Whitechapel.
Read our interview with an Air Ambulance pilot.
London's Air Ambulance: its staff walk on fire to keep it flying.