SEA08FA062

The pilot's spatial disorientation and loss of situational awareness. Contributing to the accident were the dark night and the task requirements of simultaneously monitoring the cockpit instruments and the other airplane.

The pilot was flying a night, single-pilot, cargo flight over water between two islands. He had routine contact with air traffic control, and was advised by the controller to maintain 6,000 feet at 0501 hours when the airplane was 11 miles from the destination airport. Two minutes later the flight was cleared for a visual approach to follow a preceding Boeing 737 and advised to switch to the common traffic advisory frequency at the airport. The destination airport was equipped with an air traffic control tower but it was closed overnight. The accident flight's radar-derived flight path showed that the pilot altered his flight course to the west, most likely for spacing from the airplane ahead, and descended into the water as he began a turn back toward the airport. The majority of the wreckage sank in 4,800 feet of water and was not recovered, so examinations and testing could not be performed. As a result, the functionality of the altitude and attitude instruments in the cockpit could not be determined. A performance study showed, however, that the airspeed, pitch, rates of descent, and bank angles of the airplane during the approach were within expected normal ranges, and the pilot did not make any transmissions during the approach that indicated he was having any problems. In fact, another cargo flight crew that landed just prior to the accident airplane and an airport employee reported that the pilot transmitted that he was landing on the active runway, and was 7 miles from landing. Radar data showed that when the airplane was 6.5 miles from the airport, at the location of the last recorded radar return, the radar target's mode C altitude report showed an altitude of minus 100 feet mean sea level. The pilot most likely descended into the ocean because he became spatially disoriented. Although visual meteorological conditions prevailed, no natural horizon and few external visual references were available during the visual approach. This increased the importance of monitoring flight instruments to maintain awareness of the airplane attitude and altitude. The pilot's tasks during the approach, however, included maintaining visual separation from the airplane ahead and lining up with the destination runway. These tasks required visual attention outside the cockpit. These competing tasks probably created shifting visual frames of reference, left the pilot vulnerable to common visual and vestibular illusions, and reduced his awareness of the airplane's attitude, altitude and trajectory.

HISTORY OF FLIGHT On January 14, 2008, at 0508 Hawaiian standard time, N410UB, a Hawker Beechcraft Corporation 1900C, was lost from radar over the ocean about 6.5 nautical miles south of the Lihue Airport, Lihue, Hawaii, located on the island of Kauai. Alpine Aviation Inc., doing business as Alpine Air, was operating the airplane as an on-demand cargo flight, AIP 253, under the provisions of 14 Code of Federal Regulations (CFR) Part 135. The airline transport pilot, who was not located, is presumed to have been killed, and the airplane was destroyed. Night visual meteorological conditions prevailed, and an instrument flight rules (IFR) flight plan had been filed. The flight departed Honolulu International Airport, Honolulu, Hawaii, on the island of Oahu, at 0443, and was destined for Lihue. According to the operator, the pilot was making his first flight after coming off of a rest period. The purpose of the flight was to transfer mail to Lihue, with a return flight to Honolulu later that same day. The flight was scheduled to arrive at Lihue about 0515. A Safety Board air traffic control specialist reviewed the air traffic control information surrounding the accident flight. The pilot contacted the Honolulu Control Facility (HCF) controller at 0443:23, and was later advised to climb to 10,000 feet mean sea level (msl). The pilot was then advised to contact approach. At 0449:08, the pilot contacted approach and advised that the airplane was climbing to 10,000 feet msl. At 0453:50, the flight crew of Aloha Airlines (AAH) 917 contacted the HCF controller and advised that they were climbing to 12,000 feet msl, and they could see the Beech 1900. They were advised to maintain visual separation with the Beech 1900, and cleared to proceed direct to Lihue. At 0454:24, the AAH 917 flight crew requested to level off at 14,000 feet. About 4 minutes later, AIP 253 was instructed to descend at pilot discretion and maintain 2,000 feet. The controller verified that the pilot had Lihue weather, and provided him with the current altimeter setting. A few seconds later, the controller advised AIP 253 that he had traffic overtaking him and that he should expect a visual approach to follow the traffic. At 0459:50, the HCF controller began providing the relieving controller a position relief briefing. After the relieving controller advised he had no questions about the briefing, the controller being relieved transferred control of the position. At 0501:08, the HCF controller instructed AIP 253 to maintain 6,000 feet, and the pilot acknowledged. About 6 seconds later, the controller asked AAH 917 if they still had visual contact with AIP 253 and the AAH 917 crew indicated, "Yes, sir, he's, ah, no factor." AAH 917 was then cleared to 2,000 feet msl and told to maintain visual separation with AIP 253. At 0502:39, the HCF controller advised the AAH 917 crew to report the field in sight. The flight crew replied that they had visual contact with the airport. The HCF controller then cleared AAH 917 for a visual approach into Lihue airport, terminated radar services, and instructed the flight crew to change to the advisory frequency and report on the ground. At 0503:30, the HCF controller instructed AIP 253 to, "Follow the Boeing 737, cleared visual approach to Lihue airport. Radar service terminated. Change to advisory frequency approved and report on the ground please." A few seconds later, the pilot replied, "OK, we'll follow him in visual approach and, ah, we're switching (unreadable). So long." At 0506:53, the HCF sector 2 (R2) controller called the sector 3 (R3) controller stating that he was monitoring the sector frequency and was ready to receive a position briefing in order to separate the two sectors. The R3 controller indicated that there were two visual approaches at Lihue. At 0507:26, according to radar data, the minimum safe altitude warning (MSAW) aural and visual alarms activated on AIP 253 on the R3 controller's radar display for 32 seconds. The controller was not in contact with the pilot when the warning occurred, so the pilot was not advised of the MSAW alert. Thirteen seconds later, AAH 917 canceled the need for radar service inbound to Lihue. At 0507:58, AIP 253 was lost from radar about 6.5 miles south-southeast of the airport, and the radar data showed an altitude of minus 100 feet mean sea level. At 0515:17 and 0518:06, the R2 controller attempted to reestablish contact with the pilot, but was unsuccessful. The AAH 917 flight crew submitted a written statement. The captain reported that during the flight from Honolulu to Lihue, they were advised of an airplane overhead at 10,000 feet. They called the traffic "in sight" and were given a direct clearance to Lihue. They continued their climb to 14,000 feet and maintained visual separation with the other airplane. They accelerated to cruise speed, and were given a clearance to 10,000 feet. They were able to maintain visual separation with the other airplane as they passed it about the 3 o'clock position and a few miles laterally. They were approximately 40 miles from the Lihue airport when they were given a clearance to descend to 2,000 feet. They visually identified the airport approximately 25 miles from their current position and were given a visual approach to Lihue. Air traffic control advised them to contact the common traffic advisory frequency and they made position reports prior to landing. During their approach to landing, they heard Alpine Air come on the frequency and communicate his position from Lihue as, "15 southeast of the airport." The first officer later heard a position report from Alpine Air reporting, "...about 7 miles from the airport." There was no distress call on the frequency, nor was there any indication that there was a problem. When they contacted air traffic control for departure, the captain said, "They asked us to look for a Beechcraft on the ground because they were still waiting for a cancellation from the aircraft." The captain reported that they saw an aircraft that appeared to be a Beechcraft on the ramp in the distance. One of the assistant chief pilots for Alpine Air-Hawaii submitted a written statement. At 0623, the assistant chief pilot was notified that the airplane had not arrived in Lihue. He was about 8 minutes from landing at Honolulu and contacted HCF to ask about the whereabouts of the airplane. The HCF controller advised him that the flight plan had been canceled at 0515. After the assistant chief pilot landed, he confirmed with the Lihue ground crew that the airplane was not on the ground. He then contacted HCF and advised them that the airplane had not arrived at Lihue. HCF then reported that the AAH 917 flight crew had confirmed that the airplane was on the ground so the clearance was canceled, but that they did not receive a cancellation directly from the accident pilot. The assistant chief pilot then advised HCF to contact the Coast Guard and Lihue fire rescue. The Coast Guard indicated that debris from an airplane was initially identified floating on the ocean surface at 0848, approximately 11 miles south-southwest of the airport. The water depths in the search area were up to 800 fathoms (4,800 feet). Additional debris was identified and collected and then transported to the Coast Guard station at Lihue. The Coast Guard discontinued the search on the afternoon of January 15. PERSONNEL INFORMATION Pilot Information The pilot, age 38, held an airline transport pilot certificate for multi-engine land issued on November 4, 2006, and was issued a type rating in the Beech 1900 on October 12, 2007. The pilot also held a type rating for a Bombardier CL-65 with second-in-command privileges. In addition, the pilot held a flight instructor certificate for single-engine land. The pilot held a first-class airman medical certificate issued on January 7, 2008, with no limitations. On the medica