The London Air Ambulance service is marking its 25th anniversary with a fundraising push..
The service, established in 1989 in response to a critical report claiming victims of major trauma were dying unnecessarily, says it is is in desperate need of a second helicopter.
It has treated over 30,000 critically ill patients within the M25 and claims it could tend to an additional 400 patients per year with a second helicopter.
In 2013, the service treated 1,819 patients across London.
Over a third of call-outs were related to road traffic collisions and just over a quarter were falls from height, while 23 per cent were stabbings.
In the past 12 months, the air ambulance attended to 80 trauma victims in Redbridge and 51 in Waltham Forest.
Adam Gage, 24, of Dale View Crescent, in Chingford claims his life was saved by London Air Ambulance in 2007 following a serious motorcycle accident in which he suffered a life-threatening brain injury.
He said: "They saved my life. If it wasn't for them, I would have died and I can't thank them enough for that.
"The paramedics do a fantastic job saving lives every day; it must be one of the hardest jobs in the world."
Graham Hodgkin, LAA chief executive officer, said: "It is thanks to the generosity of the people of London that we are here today commemorating this milestone.
"30,000 people have benefited from our life saving service and many of our critically injured patients have returned to their families and communities to live healthy lives."
"We urge the people and businesses of London to sign up as regular supporters to the charity to help us save more lives together."
The helicopter is used during daylight hours and rapid response cars are used at night.
The service has the world's highest survival rate for performing open chest surgery at the roadside, and a senior doctor is on board the aircraft as well as paramedics at all times.