AN air ambulance service has had its trial period extended for another month.

The helicopter has proved so successful that the Great North Air Ambulance (GNAA) charity has found funds to keep it in the air.

In the three weeks it has been based at Teesside Airport, the ambulance, which is funded entirely by public donation, has flown 21 missions.

GNAA already has a long-established helicopter based in Blyth, Northumberland, and wants to make the Teesside ambulance a permanent fixture.

The two helicopters mean that paramedics can reach the scene of an accident within ten minutes.

However, it costs £70,000 to keep the Teesside ambulance flying for one month.

Grahame Pickering, chief executive of GNAA, said: "This ambulance belongs to the people and it's essential that they continue to financially support this service.

"It has already proved that it is needed in this area so we just need to make sure that it stays here."

The charity has been the subject of a political row recently after being accused of impinging on the Tees East and North Yorkshire Ambulance Service (Tenyas), which operates its own charity-backed helicopter from Leeds-Bradford Airport.

Trevor Molton, chief executive of Tenyas, criticised moves by the GNAA to raise funds in North Yorkshire.

But Mr Pickering has denied any moves to raise funds in the area.

Mr Pickering believes that there is room for both helicopters.

The charity is appealing for more volunteers to help its efforts and is looking for North-East businesses that want to play a part in sponsoring the ambulances.

GNAA can be contacted at The Imperial Centre, Grange Road, Darlington, or by telephoning (01325) 487263.