ANALYSIS

Accident Sequence

The air tour flight departed LIH, on the southeastern part of the island, and headed west to begin a clockwise tour around the island. Weather forecasts for the afternoon included VFR conditions with the possibility of reduced visibility in thunderstorms and heavy rain. The pilot stated that, while flying the helicopter along the island s northern coastline, he maneuvered the helicopter to avoid traffic, and it entered a storm with heavy rain and reduced visibility. The passengers reported that the helicopter made no evasive maneuvers before entering the adverse weather.

The pilot stated that, while in the heavy rain, he descended the helicopter to maintain visual reference to the beach. The pilot then decided to turn back, and, while doing so, the helicopter s airspeed went to zero, and the helicopter rapidly descended. The pilot added full power and control inputs, but the helicopter continued to descend, and it crashed into the water several hundred feet off shore. Survivors reported they observed heavy rain, thunder, and lightning while they were in the water.

Microburst Phenomena

A weather study found that satellite infrared imagery for the location and timeframe of the accident indicated the rapid development of cumulus clouds capable of producing heavy rain showers, and stability and energy indices indicated potentially strong updrafts and downdrafts. The heavy rain showers and building thunderstorm activity reported by witnesses and the sounding profile supported the presence of embedded wet-type microburst activity. Statements from the pilot and passengers regarding the helicopter s rapid descent in torrential rain are consistent with an encounter with a microburst event.

Weather-Reporting Facility Limitations

No weather reporting facility is located on the north end of the island where the accident occurred, and the weather facility on the south end of the island is unable to observe the weather on the north end reliably because of interference from high terrain in the middle of the island.

The WSR-88D radar s depiction of the convective area showed only light showers in the immediate vicinity of the accident site; however, the actual weather conditions were likely much stronger than what was depicted. Although a radar system capable of accurately observing the north end of the island could not have detected the presence of a microburst, the characteristics of the storm encountered by the accident helicopter (and two of three other tour helicopters in the area) would have produced strong reflectivity returns.

In the absence of reliable and timely official weather information, Kauai air tour pilots typically use their own judgment on the basis of the appearance of the weather to determine whether to proceed. Because the island s unique weather patterns involve daily, brief, localized rain showers, it is not unusual for Kauai air tour pilots to encounter and briefly penetrate areas of precipitation during tours. For example, of the three other tour pilots who approached the storm associated with the accident, one elected to turn back without entering the conditions and two chose to fly through it. Because of the rapidly changing characteristics of the storm, each pilot likely encountered different conditions. The three pilots (including the accident pilot) who entered the storm found that they did not quickly break out of the weather as expected.

Federal Aviation Administration Surveillance of Air Tours in Hawaii

One year before this accident, an air tour accident involving Bali Hai Helicopter Tours, Inc., occurred on the island of Kauai on September 24, 2004, after the pilot decided to continue the flight into deteriorating weather rather than deviate from his tour route; the helicopter entered IMC and crashed into mountainous terrain, killing the pilot and the four passengers. During the Safety Board s investigation of that accident, the Board noted that, for a number of reasons, the Honolulu FSDO has not been able to enforce the SFAR 71 regulations and deviation authorizations adequately. This situation and other factors led the Board to conclude in the Bali Hai accident report that, 'because the Honolulu FSDO is not providing direct surveillance of and enforcement of SFAR 71, pilots continue to violate SFAR 71 and the certificate of waiver or authorization requirements, either intentionally or unintentionally, thus, placing themselves and their passengers at unnecessary risk for accidents, particularly in marginal weather conditions.'

The Board determined that a contributing factor in the Bali Hai accident was 'inadequate FAA surveillance of SFAR 71 operation restrictions' and issued a safety recommendation in the report to address the issue.32

At the time of the Heli-USA accident, the Honolulu FSDO still did not have a means to provide direct surveillance of air tour activities. Although some operators had FAA-approved procedures that allowed pilots to descend below the SFAR 71 minimum altitudes to avoid unforecasted weather, provided that they canceled their tours and returned to base under Part 135 rules, there is evidence that pilots from multiple operators were not properly following these procedures and that there was little threat of enforcement consequences for doing so. Of the three pilots who chose to enter the adverse weather, all had to descend below the SFAR 71 minimum altitude to maintain visual contact with the shore. Although one pilot reported he canceled his tour and returned to base, another pilot (the accident pilot) crashed while attempting to reverse course, and the pilot who successfully made it through the storm at 300 feet agl continued his tour, rather than cancel it and return to base as required. The Safety Board is concerned that, without adequate FAA surveillance, the very safety provisions that were put in place to protect passengers from flight in unsafe weather conditions could be used by some pilots to enter rather than avoid such weather to continue revenue flights, placing themselves and their passengers at unnecessary risk for accidents.

Survivability Issues

Although each occupant on the accident flight wore a PFD and received instruction on its use as required under SFAR 71, not all were successful.

32 On February 13, 2007, the Safety Board adopted the report, which contained Safety Recommendation A-07-21, to recommend that the FAA 'develop a permanent mechanism to provide direct surveillance of commercial air tour operations in the State of Hawaii and to enforce commercial air tour regulations.

the PFD, exiting the helicopter, and properly inflating the PFD, even though all were physically capable of doing so. Of the three passengers who were killed, none sustained any serious or incapacitating trauma injuries during the impact sequence, and each died of drowning or drowning-related circumstances. Staff considered several factors that may have affected each passenger s outcome, including the speed at which the helicopter sank, PFD-donning and egress procedures, safety briefing clarity, and the mechanical condition of the PFDs.

Lack of Helicopter Flotation Equipment

The helicopter sank quickly; thus, the passengers had little time to help themselves or others before they were submerged. According to the FAA, 'while the proper donning and securing of a life preserver may not take a lot of time under normal non-stressful situations, it can be a time-consuming process in a time of high stress.'33 The Safety Board notes that, although some survivors reported they either experienced or observed other passengers experience difficulties in completing the PFD and egress procedures, none of the difficulties alone (such as the one passenger s difficulties with the headset) should have rendered survival impossible.

In its 1995 special investigation report (SIR) on the safety of the U.S. air tour industry,34 the Safety Board noted that the combined use of PFDs and helicopter flotation equipment would provide the optimum level of safety for air tour passengers in the event of emergency ditching. In the SIR, the Board pointed out that, although the FAA s original draft of SFAR 71 called for the use of both PFDs and helicopter flotation systems, the final version allowed Hawaii air tour operators to provide only one or the other. The Board urged the FAA to reconsider this provision of SFAR 71 and to evaluate the use of helicopter floats for other overwater air tour locations.

In response to the SIR, on October 22, 2003, the FAA issued a notice of proposed rulemaking (NPRM) for national air tour safety standards that stated the following:

The FAA has determined that equipping certain helicopters with floats for over-water operations increases the likelihood of occupant survival in the event of an emergency water ditching. Floats would allow the helicopter to remain on the surface of the water for a longer period of time, thus allowing the occupants time to exit while the helicopter is still on the surface of the water.

In the NPRM, the FAA also stated that it recognized the need for more stringent flotation equipment requirements for commercial air tours and proposed that 'single-engine helicopters and certain multi-engine helicopters operated in commercial air tours over water would have to be equipped with fixed or inflatable floats unless the flight over water is necessary only for take off or landing.' However, when the FAA issued the final rule on February 8, 2007, the rule stated that helicopters need not be equipped with floats if each occupant is wearing a life preserver while the helicopter is within power-off gliding distance of the shoreline.

33 This statement is in the FAA s notice of proposed rulemaking, 'National Air Tour Safety Standards,' DocketNo. FAA-1998-4521, Notice No. 03-10, issued on October 22, 2003, in Federal Register, Vol. 68, No. 204.

34 National Transportation Safety Board, Safety of the Air Tour Industry in the United States, SpecialInvestigation Report NTSB/SIR-95/01 (Washington, D.C.: 1995).

In this accident, helicopter floats would have likely kept the helicopter on the water surface longer. Because all of the passengers (including the nonsurvivors) either donned or attempted to don their PFDs and because all likely perceived the immediate need to exit the helicopter, the Safety Board concludes all of the passengers would have had the opportunity to don their PFDs and egress the helicopter successfully had the helicopter not sunk so quickly.

The Safety Board also notes that the accident helicopter was initially traveling over the shore but ended up over the ocean as the emergency progressed. Further, the ditching emergency was not related to a loss of engine power. Therefore, the Board concludes that, with regard to helicopter flotation equipment, there should be no exceptions for overwater takeoffs and landings and no distinction between single- and multi-engine helicopters.

Personal Flotation Device Inflation Issues

During demonstrations of representative PFDs, test subjects reported that it was relatively easy to don the PFDs and inflate both chambers, even when the procedures were performed in the water. According to the demonstrations of the two PFD models, the test subjects found it was not possible to float facedown with both chambers inflated.

Examination of the recovered PFDs found that, of the three PFDs that were worn by the survivors, only one had both chambers inflated. One recovered PFD with an uninflated chamber showed no evidence that any attempt had been made to inflate it, and it functioned properly when tested. The other recovered PFD with one uninflated chamber showed evidence that someone had attempted to inflate it but was unsuccessful, likely because of an incompletely seated cylinder.

Because the PFD worn by the passenger who was found floating facedown was not recovered for examination, it was not possible to determine its inflation configuration or to conclude whether both chambers could have inflated if the handles were pulled. Also, because it is not known at what point in the egress sequence this passenger drowned, it is not possible to conclude whether a fully inflated PFD could have saved this passenger s life.

Of the two PFDs provided for the water-immersion demonstration, one had a chamber that failed to inflate because of an improperly seated cylinder. Also, another Hawaii air tour operator reported 18 of 26 cylinders were loose on 13 PFDs examined. All of these PFDs (the 2 provided for testing and the 13 others examined) had been recently retired from service after about 1 year of use in accordance with the manufacturers recommendations and the Honolulu FSDO s requirements for air tour operators. Because the PFDs must remain sealed in their pouches to meet airworthiness requirements, it is not possible for the operators to inspect the cylinders themselves between recommended inspection intervals. The Safety Board is concerned that the number of improperly seated cylinders found within such a small sample size may indicate that similar problems exist elsewhere and could include instances in which both cylinders on one PFD are not secure.

The Safety Board concludes that, without a solution to the cause of and how to prevent inflation cylinder unseating, passengers are no longer assured that their flotation devices will perform as designed in the event of an emergency and that further evaluation is needed to determine whether design, maintenance, and/or in-service handling issues are related to the problem. Although the PFDs are equipped to allow for oral inflation of the chambers, the Board is concerned that, in the case of passengers who cannot swim, the 2-second cylinder inflation would be more preferable than attempting oral inflation and that panicked passengers may forget about the oral inflation option.

PROBABLE CAUSE

The National Transportation Safety Board determines that the probable cause of the accident was the pilot s decision to continue flight into adverse weather conditions, which resulted in a loss of control due to an encounter with a microburst. Contributing to the accident 0was inadequate Federal Aviation Administration surveillance of Special Federal Aviation Regulation 71 operating restrictions. Contributing to the loss of life in the accident was the lack of helicopter flotation equipment.