BALTIMORE, Sept. 12 (UPI) -- Helicopters servicing drilling platforms and ships in the Gulf of Mexico crash on average six times per year, mostly from mechanical failure, a report says.

The study by the Johns Hopkins Center for Injury Research and Policy found that from 1983 to 2009, 178 crashes resulted in 139 deaths, including 41 pilots and three co-pilots, an average of about five deaths annually, a release from the center said Monday.


Of the total crashes, 68 of them, 38 percent, were blamed on mechanical failures, with bad weather the second most common cause and cited in 16 percent of the crashes.

Crashes in bad weather were responsible for the largest number of deaths, with the National Transportation Safety Board blaming pilot error for many of them in that the pilot should not have proceeded given the forecast or observed bad weather.

Many of the crashes resulted in the helicopters sinking, despite the fact that most helicopters are being equipped with pilot-activated flotation devices.

"Our findings suggest that efforts to reduce crashes and deaths must address mechanical failure, non-activation of flotation devices, and pilot error," Johns Hopkins researchers Susan P. Baker said.

"This study raises concern about the safety of helicopter flights related to oil and gas operations in the Gulf of Mexico, particularly during bad weather."