AAIB Initial Report Outlines Early Investigation

The U.K. Air Accidents Investigation Branch has released an initial report from an accident in which a Glasgow Police helicopter came down on the roof of a pub, resulting in the fatal injury of at least nine people. Three were on board the aircraft, and six were attending an event inside the building. Thirty-two other people suffered injuries, twelve serious, according to the report.

A witness described hearing a noise like a loud “misfiring car”, followed by silence. He then saw the helicopter descend rapidly. It crashed through the roof of The Clutha Bar, a single story building on Stockwell Street in central Glasgow.

The initial evidence indicated that the helicopter struck the flat roof of the single story building with a high rate of descent and low/negligible forward speed. Preliminary examination showed that all main rotor blades were attached at the time of the impact but that neither the main rotor nor the fenestron tail rotor were rotating. The impact forces caused the roof of the bar to collapse and the helicopter entered the building; its forward section coming to rest on and amongst building debris.

Very extensive damage and disruption of the helicopter structure and components resulted from the impact forces and from contact with the collapsing building. The helicopter did, however, remain approximately upright.

Initial assessment provided no evidence of major mechanical disruption of either engine and indicated that the main rotor gearbox was capable of providing drive from the No 2 engine power turbine to the main rotor and to the fenestron drive shaft. Clear impact distortion of the structure had caused a splined shaft on the drive train from the No 1 engine to disengage, preventing a similar continuity check.

According to the report, the helicopter was not required to have and was not fitted with flight recorders, nor did its systems provide a continuous recording of helicopter parameters. However, some systems record fault codes, as they occur, in memory that is not crash-protected. Those, and systems that can record camera images and audio, will be examined and analyzed.

Radar data covering the helicopter flight has been recovered. That and radio communications are also being analyzed, and closed-circuit television recordings will be reviewed as part of the ongoing investigation.

FMI: Initial Report