The Dutch Safety Board has published a report on its investigation into a December 2007 accident involving a Royal Netherlands Air Force Boeing AH-64D Apache attack helicopter, attributing the mishap to insufficient pre-mission planning, high workload and a lack of supervision.
During a night flying training exercise the Apache hit six power lines crossing the River Waal, causing a massive power outage in the Bommelerwaard region for almost 50h. The crew, which comprised one experienced pilot and one yet to achieve combat-ready status, managed to make a precautionary landing in a field, with one suffering minor injuries.
The investigation found that insufficient time was spent on verifying potential hazards ahead of the sortie, and that the aircraft commander was busy inside the front cockpit at the time of the incident without having notified the back-seat pilot, who was flying the aircraft. A short "I am inside" message, which is standard procedure, would have enabled the rear pilot to make better use of his night vision equipment by scanning the area more actively, it adds.
The 10 February report also cites as contributory factors a 20% reduction in Dutch Apache training hours, which was to have been compensated using a tactical simulator that is currently not operational. Of the remaining 140h of training, a substantial part is amassed during operations in Afghanistan, where low flying is not regularly practised. The board also criticised current safety and auditing procedures.
In response, the air force has amended some of its procedures, including signalling potential hazards on maps, and is working to identify other improvements.