Accident - Aviation NTSB Report

HISTORY OF THE FLIGHT

On September 23, 2005, about 1415 Hawaiian standard time,1 an Aerospatiale AS350BA helicopter, N355NT, registered to Jan Leasing, LLC, and operated by Heli-USA Airways, Inc., of Las Vegas, Nevada, encountered adverse weather and crashed into the Pacific Ocean several hundred feet off the coast of Kailiu Point, near Haena, Hawaii, on the island of Kauai. The sightseeing air tour flight was operated under the provisions of 14 Code of Federal Regulations

(CFR) Part 135 and visual flight rules (VFR) with a company flight plan in effect. Localized instrument meteorological conditions (IMC) prevailed in the vicinity of the accident site. Three passengers were killed, and the commercial pilot and two other passengers received minor injuries. The flight departed from Lihue Airport (LIH), Lihue, Hawaii, on the island of Kauai, at 1354 for the intended 45-minute tour. The flight was operated under Special Federal Aviation Regulation (SFAR) 71, 'Special Operating Rules for Air Tour Operators in the State of Hawaii,'2 and in accordance with a certificate of waiver or authorization approved for Heli-USA by the Federal Aviation Administration (FAA) Honolulu Flight Standards District Office (FSDO) in Honolulu, Hawaii.3

The flight proceeded westbound from LIH, which is on the southeastern part of the island, on the operators standard clockwise tour route around the island (see figure 1).4

1 All subsequent times are reported in Hawaiian standard time based on a 24-hour clock, unless noted otherwise. Hawaiian standard time is coordinated universal time minus 10 hours.

2 SFAR 71 prescribes the operating rules for airplane and helicopter air tours conducted in Hawaii. It includes requirements for helicopter flotation equipment, performance plans, and operating limitations; minimum flightaltitudes; and passenger briefings.

3 Under SFAR 71, the minimum altitude for tour flights is 1,500 feet above ground level (agl) and no closer than1,500 feet to any person or property, unless otherwise authorized. Heli-USA s certificate of waiver or authorization allows its pilots to deviate from the minimum altitude requirement and to descend as low as 500 feet agl over FAA-approved site-specific locations and traverse FAA-approved transition segments as low as 1,000 feet agl.

4 The operator reported that the intended tour route was to depart from LIH and proceed west, which is the standard harbor departure, to the first tour site, Hanapepe Valley. From there, the tour was to proceed northwest to Waimea Canyon, then north to the Na Pali Coast, then northeast along the coastline to the northern end of the island to Kailiu Point. The tour was then to proceed south to Hanalei Valley and then to Waialeale Crater before returningto LIH.

The pilot reported that the weather and visibility were good during the initial part of the tour. The pilot stated that he flew the helicopter over the Na Pali Coast on the northern part of the island at 2,000 feet above ground level (agl) and that the weather along the coastline was clear and without rain. The pilot stated that he saw rain showers offshore as the flight approached Kee Beach and Kailiu Point on the northern part of the island. The pilot reported that, as the flight came around Kailiu Point, he 'suddenly saw [a McDonnell Douglas (MD)-500 helicopter] coming straight for [his helicopter]' and that he made a left turn to avoid it. He stated that, when he leveled his helicopter out of the turn, it was 'already inside the storm,' and it encountered heavy rain. Two passengers reported that they saw another helicopter flying in the opposite direction but that it was far below them, and one passenger stated that it was far enough below them that she thought it was a bird. Both of these passengers said that their helicopter made no evasive maneuver, or any maneuver, before entering what they described as 'a wall of pure rain and thick clouds.'

The pilot stated that, while the helicopter was in the heavy rain, he could still see down and to the right to the coastline and that he reduced the helicopter s airspeed and initiated a descent to maintain visual reference to the beach. One passenger reported that he could not see anything in the heavy rain and that he was about to say something about this to the pilot when the pilot announced that they were turning back. The pilot said that he started a right turn over the beach and that, during the turn, the helicopters airspeed dropped to zero and the helicopter started to rapidly descend.

The pilot stated that he instructed the passengers to open the doors to get ready for the water impact and that the helicopter hit the water, bounced back into the air, and continued to spin. The pilot said that he transmitted a mayday call on the radio and that the helicopter impacted the water again and remained on the surface spinning. The pilot stated that the helicopter was submerged to the belly panel when it stopped spinning, then it rolled to the right and immediately began to sink.

A pilot flying a tour for another operator said that he heard the mayday call over the common traffic advisory frequency (CTAF)5 and twice attempted to fly his helicopter in the Kee Beach area to try to locate the downed helicopter but was unable to do so because of poor visibility. While returning to the airport to alert rescue authorities, he saw another Heli-USA helicopter in flight and used the CTAF to inform that pilot of the mayday call. That Heli-USA pilot then conducted a brief search and spotted an oil slick on the water extending toward the area of poor weather. He made an unscheduled landing on a beach to let out his passengers then searched the area near the oil slick. He said that the visibility was low but usable and that he saw debris and people in the water. He used his radio to direct U.S. Navy aircraft into the area.

PERSONNEL INFORMATION

The pilot, age 43, held a commercial pilot certificate with a rating for rotorcraft helicopter and a private pilot certificate with a rating for airplane single-engine land; he did not hold an instrument rating. His most recent FAA second-class airman medical certificate was issued on October 29, 2004, with the limitation that he 'shall possess glasses for near and intermediate vision.'

A review of the pilot s logbook indicated that, on the date of the accident, he had accumulated about 2,814 hours total flight time, which included about 29 hours simulated instrument experience, 939 hours night flight, and 334 hours in AS350-series helicopters. The pilot reported that, during the 90 days, 30 days, and 24 hours before the accident, he had flown about 176 hours, 115 hours, and 6 hours, respectively. He reported that he had conducted about 233 tours around Kauai and that those tour routes were similar to the route of the accident flight.

The pilot was hired by Heli-USA on July 29, 2005, about 2 months before the accident, and he completed his initial training and received 4.5 hours of flight instruction at the Heli-USA base in Las Vegas. The initial training included 40 hours of ground instruction, in accordance 5 Pilots can use CTAFs to carry out advisory practices while operating in airspace that lacks an operating air traffic control tower.

6 The pilot made the unscheduled landing to let out the passengers so that he could use his helicopter to assist with the emergency. Two of the passengers volunteered to remain on board to help search for the downed helicopter.

AIRCRAFT INFORMATION

The helicopter was manufactured in 1987 as an AS350B model and was converted to an AS350BA model in 1997.7 It was powered by a Turbomeca Arriel 1B turboshaft engine. It was configured with three seats in the front row and four seats in the second row, and the pilot position was the front right seat. Each passenger seat was equipped with a lap belt, and the pilot seat was equipped with a lap belt and shoulder harness. The helicopter was not equipped, and was not required to be equipped, with flotation equipment.8

A review of the maintenance records indicated that the helicopter had accumulated about 11,483 total hours and that the engine s total time was about 13,560 hours. The helicopter s most recent continuous airworthiness inspection, a 100-hour inspection, was completed on September 16, 2005. At the time of the accident, the helicopter had accumulated about 39 hours since the inspection.

METEOROLOGICAL INFORMATION

The only official National Weather Service (NWS) reporting facility on the island of Kauai was located at LIH, about 20 miles southeast of the accident site, at an elevation of 153 feet above mean sea level. The airport was equipped with an automated surface observing system augmented by certified NWS observers as necessary. At 1353,9 the meteorological aerodrome report (METAR) included winds from 090° at 9 knots, visibility unrestricted at 10 miles, and few clouds at 2,400 feet. The METAR for 1453 included the same wind and visibility conditions but with few clouds at 1,500 feet.

The Hawaii Area Forecast (FA) issued at 1140 on September 23, 2005, and valid until midnight, indicated that a tropical storm was about 300 miles northeast of Hilo, Hawaii.

7 The conversion, performed in accordance with the manufacturers Service Bulletin 1.35, included the replacement of the main and tail rotor blades and other retrofits to increase the helicopter s useful load and other performance parameters.

8 According to SFAR 71, a single-engine helicopter may be used to conduct air tours in Hawaii withouthelicopter flotation equipment, provided that the flight either does not go beyond the shore or that each person onboard the helicopter is wearing approved flotation gear. Per Heli-USA s operations specifications, each person onboard the helicopter was wearing a quick-donning life vest in a pouch around his/her waist. Following the accident, Heli-USA voluntarily began to equip its Hawaii-based helicopters with flotation equipment. By December 2006, Heli-USA had five Hawaii-based helicopters, and all were equipped with floats.

9 FAA and NWS weather information products are reported in coordinated universal time. The times in this section have been converted to Hawaiian standard time.

510 The FA indicated that, for Kauai and adjacent waters, conditions were forecasted to include scattered clouds at 2,000 feet, ceilings broken to overcast at 3,500 feet with tops to 12,000 feet, temporary ceilings below 3,000 feet in cumulonimbus clouds with tops to 40,000 feet, and visibility below 3 miles in thunderstorms and heavy rain. The outlook was for VFR conditions to prevail.

An in-flight weather advisory,11 airmen s meteorological information (AIRMET) Sierra update 8 for instrument flight rules conditions, was issued at 1355 and was valid until 1800. The AIRMET warned of mountain obscuration over the islands of Oahu and Kauai and indicated that the mountains would be temporarily obscured above 1,500 feet because of clouds, thunderstorms, and rain. The conditions were expected to continue beyond 1800.

The terminal aerodrome forecast (TAF) closest to the accident site was for LIH and was issued at 0744 and was valid at 0800 for a 24-hour period. From 0800, the forecast was for winds from 080° at 8 knots, visibility better than 6 miles, and scattered clouds at 2,500 feet. From 1400, the forecast was for winds from 100° at 12 knots, visibility better than 6 miles with rain showers in the vicinity, scattered clouds at 2,500 feet, and ceiling broken at 3,500 feet, and, temporarily between 1400 and 1800, visibility 5 miles in moderate rain showers, scattered clouds at 2,500 feet, and overcast at 3,500 feet.

Meteorological Study of Weather Data

The closest NWS Weather Surveillance Radar-1988 Doppler (WSR-88D) was located in Numila, Hawaii, on the island of Kauai, about 21 miles south of the accident site. The WSR-88D is a computer-controlled radar system that automatically creates a complete series of scans in a specific sequence. The scan completed at 1403 depicted areas of reflectivities of 15 to 25 decibels (dBZ) in the immediate vicinity of the accident site. Echoes in the 25-dBZ intensity range are typically associated with rain showers or developing cumulonimbus or other towering cumulus clouds.12 The echo intensity images derived from WSR-88D, however, do not represent the true reflectivity and/or intensity of the activity encountered by the accident helicopter; high terrain between the WSR-88D system and the accident site resulted in significant beam blockage below 5,000 feet over the accident site.13

A review of satellite imagery data14 indicated that, at 1400, low- to mid-level clouds obscured most of the island of Kauai with several areas of towering cumulus to cumulus

10 A forecast discussion bulletin issued by the NWS weather forecast office in Honolulu at 0955 indicated that the tropical storm would not directly affect the islands; however, indirect impacts, such as light trade winds and high surf, were expected.

11 In-flight advisories are forecasts to notify en route aircraft of the possibility of encountering hazardous weather conditions. The NWS weather forecast office in Honolulu issues advisories for the Hawaiian Islands.

12 Echoes of this intensity correspond with the video integrator and processor (VIP) intensity 'Level 1' or 'verylight.' According to FAA Advisory Circular 00-24B, 'Thunderstorms,' light to moderate turbulence with lightning is possible in VIP Level 1 weather.

13 A Safety Board meteorology specialist performed a beam-height calculation for the accident site.

14 Geostationary Operations Environmental Satellite number 10 data was obtained from the National Climatic Data Center and displayed on the Safety Board s Man-computer Interactive Data Access System workstation. Both

A study was performed using the upper air sounding for 1400 and the observed and derived stability parameters. The data indicated an unstable, moist, low-level environment with a relative humidity of 75 percent or more from the surface to approximately 5,000 feet. The sounding supported a moderate to high risk of thunderstorms, with the K-index15 indicating an approximate 80 percent chance of thunderstorms. The study determined that the maximum vertical velocity of the potential convective updrafts in thunderstorms was 160 knots, the wind gust or potential outflow winds from thunderstorms were about 41 knots, and the sounding was favorable for microburst development with outflow winds of 55 knots.

Microbursts are small-scale intense downdrafts, which, upon reaching the surface, spread outward in all directions from the downdraft center. This causes both vertical and horizontal windshears that can be extremely hazardous to all types and categories of aircraft, especially at altitudes below 1,000 feet, because the conditions can produce a situation in which it is difficult to control the aircraft. A typical microburst lasts about 15 minutes and occurs in a space of less than 1 mile horizontally and within 1,000 feet vertically. Due to their short life span, small size, and the fact that they can occur over areas without surface precipitation, microbursts are not easily detectable using conventional weather radar or windshear alert systems.

Weather Information Sources Available to the Pilot

According to company personnel, pilots usually obtain their weather information from a combination of sources, including the FAA Flight Service Station (FSS) in Honolulu, local television reports, various Internet sites, and the LIH automatic terminal information service (ATIS).

According to the pilot, he arrived for work on the day of the accident about 0615, obtained a printout of FAA and NWS weather information from the direct user access terminal system (DUATS)16 and noted nothing unusual about the information. The accident flight was his visible and infrared imagery was obtained surrounding the time of the accident.

15 The K-index is a measure of thunderstorm potential based on the vertical temperature lapse rate and theamount and vertical extent of low-level moisture in the atmosphere.

16 DUATS provides pilots access to FAA and NWS alphanumeric preflight weather information, such as FAs, TAFs, METARs, and AIRMETs, via personal computer.

For in-flight weather information, tour pilots also use the CTAF to exchange brief, informal statements regarding their weather observations;17 however, the high terrain in the middle of the island can limit the effective range of these transmissions.

Weather Conditions Observed by Pilot Witnesses

Three other tour pilots were conducting helicopter flights in the area of Kailiu Point within minutes before and after the accident. One pilot, who flew along the Na Pali Coast about 15 minutes before the accident flight, stated that the conditions at that time were clear with rain showers just off the point at Kee Beach. The pilot stated that he maintained an altitude of about 1,500 to 2,000 feet agl and that his flight entered heavy rain conditions when he passed Kailiu Point about 1400. He stated that he initiated a gradual descent to about 300 feet agl to maintain visual contact with the shoreline and that he did not encounter any turbulence, downdrafts, lightning, or windshear while maneuvering through the rain. He stated that his helicopter emerged from the storm abeam Haena and that he announced over CTAF that 'Haena is clear, blue, and twenty-two'18 and advised other flights to avoid the showers. He stated that unknown pilots made two inquiries over the CTAF about the intensity of the showers and that he responded 'intense' and 'heavy duty.'

Another tour pilot stated that he heard the report over the CTAF of 'heavy duty rain showers' at Kee Beach. He stated that he asked about the visibility over the CTAF but received no reply. He stated that, when his flight reached the Kee Beach area, he saw a 'super dark misty rain shower' and decided to turn his helicopter around rather than enter the weather.19 He estimated that the visibility associated with the storm at that time was about 1/8 mile or less. He stated that the air was smooth with no thunder or lightning and that the water was smooth with no white caps. He stated that he discontinued his tour and was on his way back to base when he heard the mayday calls over the CTAF.

A third tour pilot stated that he was flying his helicopter about 1,500 feet agl headed northeast along the Na Pali Coast when he heard the mayday calls. Shortly thereafter, he saw the

17 These informal air-to-air communications differ from pilot reports (PIREPs), in which pilots provide weatherobservation reports in a standard format to FAA ground facilities that serve as collection points for the exchange of PIREP information with other pilots and en route aircraft. According to the FAA Aeronautical Information Manual, among other uses, air traffic control facilities can use PIREPs for air traffic weather-avoidance procedures; FSS can use the information to brief other pilots or to provide in-flight advisories and weather-avoidance information to enroute aircraft; and the NWS can use the information to verify or amend conditions contained in aviation forecasts and advisories.

18 The pilot s statement was slang for visibility unlimited, or clear.

19 This helicopter was an MD-500, and its direction of flight was consistent with the helicopter that the accidentsurvivors reported seeing flying below their helicopter before it entered the storm.

WRECKAGE AND IMPACT INFORMATION

The wreckage was located several hundred feet off the shoreline near Kee Beach in about 60 feet of water. The wreckage was recovered on September 25, 2005, and transported to LIH for examination.

Examination revealed that control continuity could be established throughout the fuselage, and evidence of rotational signatures and component system continuity was noted. The tail boom, horizontal and vertical stabilizers, and the tail rotor system showed no evidence of preimpact anomalies. All main rotor blade root sections remained attached to the main rotor hub.

The engine remained attached to the airframe and was removed for examination. The compressor blades turned freely when manually rotated and showed no evidence of foreign object damage or anomalies. The main rotor transmission was removed for examination, and rotation occurred when the main rotor head was turned. No evidence of any preimpact mechanical malfunction of the helicopter s airframe, engine, or systems components was observed.