A 28-year study of helicopter sightseeing accidents in Hawaii suggests that rules enacted in 1994 to reduce accidents did reduce the overall number by 47 percent. However, the rules did nothing to address the main cause of accidents (mechanical failure) and may have inadvertently led to an increase in the deadliest type of accidents (weather-related CFIT). In fact, researchers with the Johns Hopkins Bloomberg School of Public Health's Center for Injury Research and Policy recommend the FAA rescind the section of the rule that sets minimum altitude for sightseeing operations at 1,500 feet AGL because it can force pilots to fly in clouds that they could easily and safely duck under. The Hawaii Helicopter Operators Association identified the potential risk and actually took the FAA to court to try and reverse the rule but lost, according to a report in Science Daily. Before the rules were enacted, only 5 percent of accidents were weather-related but in the 14 years since they've jumped to 32 percent of mishaps.
This is a companion discussion topic for the original entry at https://www.avweb.com/news/safety-rules-increasing-some-accidents-study