"A number" of helicopters from the same fleet as one that crashed into a Scottish pub have a problem with their fuel indicators, their aircraft's owner has confirmed.
One of their EC135 helicopters, leased to the police, hit the roof of the Clutha pub in Glasgow last month, killing 10 people.
The firms's 22 remaining type of choppers were grounded yesterday to undergo checks after a technical fault was found in one of them .
The firm's spokesman could not say how many helicopters had the fault, but added that the work was expected to have been completed by Sunday.
The National Police Air Service have announced that they increasing fuel levels in helicopters as a "precautionary measure" following reports of a technical issue on an aircraft.
Chief Superintendent Ian Whitehouse, National Police Air Service Chief Operating Officer, said:
“In light of the technical issue identified by Bond Air Services, as a precautionary measure, we are increasing fuel levels on all NPAS EC135 aircraft and increasing the minimum level of fuel which pilots are allowed to operate on.
The service refused to comment on any potential links to the investigation into the Glasgow crash which killed ten people.
East Anglia air ambulances have returned to service after helicopter operator Bond Air Services suspended a number of flights over a "defect" in one aircraft.
Wales Ambulance Service said two of its three helicopters had been cleared to fly with checks continuing on a third aircraft.
Police Scotland said earlier restrictions on the flight of EC135 helicopters had been lifted and their helicopter had been cleared to fly.
A spokeswoman said: "As of 3.18pm today ... the Police Scotland Air Support Unit is now fully operational."
Eurocopter, which builds EC135 helicopters, said the decision to ground some of the aircraft fleet was taken by the operator Bond Air Services:
– Eurocopter statement
Eurocopter is in close contact with Bond to fully support theactivities.
Eurocopter does not recommend any further action for the other EC135 aircraftin service around the world.
EASA [the European Aviation Safety Agency] has never issued an Airworthiness Directive(AD) to ground the EC135 fleet ever since its entry into service in 1996.
The air ambulance service for Hampshire and Isle of Wight has now been cleared to fly.
A spokesman for the Scottish Ambulance Service said that alternative services would be found to ensure that there was adequate cover for the grounded aircraft:
– Scottish Ambulance Service spokesman
Until the matter is resolved, the Scottish Ambulance Service is operating normal contingency measures whereby any patient that requires transfer by air will be taken by Coastguard and military helicopters, Scotland's Charity Air Ambulance helicopter or SAS fixed-wing aircraft.
The Air Ambulance Association has confirmed that programs are in place to ensure that all parts of the country are still covered by alternative air ambulance services:
– air ambulance association
These programs will access other air ambulances fromthe fleet of 36 aircraft across the UK to ensure the service is operational.
This does not include other air assets such as Search and Rescue Aircraft orother transportation systems that allow the fast deployment of Critical CareTeams.