A fleet of helicopters were grounded in the UK today due to fears over the safety of their fuel indication systems, taking a third of Britain's air ambulances out of service.
The alert related to a problem with a fuel gauge, during a flight by an EC 135 yesterday.
Areas affected included Dorset, Somerset, Thames Valley, the Isle of Wight, the Midlands, Scotland and Wales.
The Association of Air Ambulances (AAA), which represents the majority of the air ambulance network, said 16 of its 36 helicopters in the UK were affected by the grounding.
The helicopter that crashed into the Clutha bar in Glasgow on November 29 was a Bond-operated Eurocopter EC135 Type 2 aircraft.
A statement from Bond Air Services said: "As a precautionary measure, following an issue with the fuel indication system on one of our aircraft yesterday we temporarily suspended service operations whilst we undertook further technical investigations of our fleet of EC135s."
Police Scotland said restrictions had been lifted and their helicopter had been cleared to fly.
Wales Ambulance Service said two of its three helicopters had been cleared to fly with checks continuing on a third aircraft, while East Anglia air ambulances have also returned to service.
The National Police Air Service announced that they were increasing fuel levels in helicopters as a "precautionary measure".
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."