Midlands Air Ambulance helicopters had to be grounded after a fault was found, weeks after a tragic crash in Glasgow.
Three helicopters, used to carry critically injured people to hospital, were taken out of service after the technical problem was discovered.
They are the same model as the police helicopter that crashed onto the Clutha Vaults pub at the end of November. The death toll there rose to 10 last night when Joe Cusker, 59, from South Lanarkshire died in Glasgow Royal Infirmary.
One of the three air ambulances, based at Tatenhill in Staffordshire, was cleared for flight again at 4.30pm yesterday and was due to resume service from this morning.
Inspections on the two further helicopters based at Cosford and Strensham are continuing with a view to them returning to normal operation by Sunday.
Bond Aviation Group, the supplier of EC135 helicopters for the Midlands and North West Air Ambulances, said it had found a fault with one of its aircraft in the North West and made the decision to ground all such helicopters until further notice. North West Air Ambulance has also grounded its fleet.
Between them, Midlands Air Ambulance and North West Air Ambulance cover an area of more than 10,000 square miles and a population of 13 million people.
The Air Ambulance Service offered two of its aircraft, the Warwickshire and Northamptonshire Air Ambulance (WNAA) and Derbyshire, Leicestershire and Rutland Air Ambulance (DLRAA), to cover in the meantime. Both use the Augusta Westland 109 helicopters, which are different to the ones used in the Midlands.
West Midlands Ambulance Service spokeswoman Suzie Fothergill said: “As a service we still have access to two air ambulances - those operated by Warwickshire and Northampton Air Ambulance and Derbyshire, Leicestershire and Rutland Air Ambulance so we have no concerns about patients being put at risk by this situation.
“In addition, the crews that would have been flying today will respond on land vehicles as they would if the weather had stopped the helicopters flying.”