Accident investigators have confirmed the pilot of the Eurocopter EC135T2 that crashed through the roof of a busy Glasgow pub did not make an emergency call before impact.

Speaking to media at the scene, David Miller, deputy chief of air accident investigations at the Air Accidents Investigations Branch, says that "there were no emergency transmissions from the pilot before the accident".

Miller also says the helicopter made a vertical descent on to the roof of the Clutha Vaults. Nine people, including three crew members, died in the accident.

There was no cockpit voice or flight data recorder present in the aircraft, says Miller, but he remains hopeful data can still be extracted from on-board electronic systems, such as the FADEC on the type's twin Turbomeca Arrius 2B2 powerplants.

He says: "I can confirm that nothing detached from the helicopter in flight before the accident and all four rotor blades were attached to the rotor head after impact."

Miller was also at pains to distance the Glasgow incident from other accidents in Scotland recently, notably in the North Sea, which involved an entirely different aircraft type.

According to Flightglobal Ascend Online data, the EC135 has a reasonable safety record. Since 1998 only 23 total hull losses have been recorded, alongside a further 13 major crashes.

Of the former category, five of these were attributed to loss of control – most recently a 2010 incident in Arizona involving an EC135T1, which span out of control – three to power loss and one accident to component or system failure. No total hull losses from any mechanical failure have been recorded since 2010.