The UK Air Accidents Investigation Branch’s (AAIB) just-released final report on the fatal crash of an AgustaWestland A109E in January last year in central London does not suggest new causes, but investigators recommend preventative measures to avoid such collisions with obstacles in future. A preliminary report last year highlighted the array of altitude constraints and poor visibility the pilot was facing. The light twin hit a 719-foot-high crane jib, killing the pilot and a pedestrian in the street below.

The AAIB’s first recommendation calls for the UK CAA to require air navigation service providers to assess the effect of obstacles on VFR routes near those obstacles. It also asked the UK Department for Transport to implement a mechanism for the reporting and management of obstacle data.

On the pilot’s side, the Board suggested that pilots use a pre-departure risk assessment tool, which “might have highlighted two elevated risk factors.” The pilot might thus have sought management approval before accepting the flight, the AAIB said. Finally, the Board said that the CAA should evaluate mandating helicopter Taws as a way to detect obstacles.