The United States National Transportation Safety Board (NTSB) is calling for all Robinson R44 helicopters to be equipped with crash-resistant, bladder-type fuel tanks.
In a safety recommendation issued on Jan. 15, the NTSB urged the Federal Aviation Administration (FAA) to mandate the replacement of older, all-aluminum fuel tanks with the improved bladder-type tanks, which are designed to improve the R44 fuel system’s resistance to post-accident fuel leaks. The recommendation is derived from investigations by the NTSB and the Australian Transport Safety Bureau (ATSB) into seven accidents involving R44 helicopters with all-aluminum fuel tanks, all of which should have been survivable with minor or no injuries to the occupants, but which resulted in fatalities and serious injuries due to post-crash fires.
The industry has known for several years now about the susceptibility of R44s with all-aluminum fuel tanks to post-crash fires. On Dec. 20, 2010, manufacturer Robinson Helicopter Company issued Service Bulletin SB-78, advising owners, operators, and maintenance personnel of R44 helicopters with the older tanks to retrofit them to the new bladder-type tanks. Although the original Service Bulletin urged compliance by no later than Dec. 31, 2014, Robinson later revised the bulletin to specify a compliance date of April 30, 2013.
According to the NTSB, Robinson has made significant progress in equipping new and existing R44s with the crash-resistant fuel tanks. All new-build and factory-overhauled R44s have received bladder-type fuel tanks since 2009, and all field-overhaul kits have included the tanks since January 2013. The NTSB’s safety recommendation notes, however, that “some owners have been waiting until their helicopters are ready for the next 2,200-hour overhaul to accomplish the retrofit to minimize downtime and costs, and other owners cited additional financial reasons and no formal requirement as explanations for not accomplishing the retrofit.”
Last year, following a recommendation by the ATSB, Australia’s Civil Aviation Safety Authority issued an Airworthiness Directive that required R44 operators in that country to retrofit their helicopters with bladder-type fuel tanks by the April 30, 2013 deadline specified by Robinson. As reported in Vertical, the FAA declined at that time to issue a similar Airworthiness Directive, finding that “R44 fuel system crashworthiness does not appear inconsistent with other similar helicopters.”
Now, however, the NTSB is urging the FAA to reconsider, arguing that requiring R44 owners and operators to comply with the fuel tank retrofit will “prevent accidents and save lives.” It requests a response from the FAA on the recommendation within 90 days.
The complete safety recommendation can be found on the NTSB website.
