As The Airplane Continued Southbound, It Began A Right Turn, Then It Entered A Spiraling Right Descending Turn

Location: Kaupo, HI Accident Number: ANC23FA008
Date & Time: December 15, 2022, Local Registration: N13GZ
Aircraft: Raytheon Aircraft Company C90A Injuries: 3 Fatal
Flight Conducted Under: Part 91: General aviation – Positioning

On December 15, 2022, about 2114 Hawaii-Aleutian standard time, a Raytheon Aircraft Company (formerly Beech) C90A, twin-engine, turbine-powered airplane, N13GZ, is presumed to have sustained substantial damage when it was involved in an accident near Kaupo, Hawaii. The airline transport pilot, flight paramedic, and flight nurse are presumed fatally injured. The airplane was operated as a Title 14 Code of Federal Regulations (CFR) Part 91 air ambulance positioning flight.

The flight, operated by Guardian Flight LLC, dba Hawaii Life Flight, departed the Kahului Airport (OGG) on the Island of Maui, Hawaii, at 2053, on an instrument flight rules (IFR) flight plan. The accident airplane was destined for the Waimea-Kohala Airport (MUE) on the Island of Hawaii to pick up a patient to be transported to Honolulu, Hawaii. Dark night conditions prevailed at the time of the accident. A preliminary review of archived voice communication information from the Federal Aviation Administration (FAA) revealed that shortly after departure from OGG at 2055, the pilot contacted the departure air traffic control (ATC) specialist on duty, indicating the flight was at 1,000 ft msl, climbing to 11,000 ft msl.

About 2102, the departure ATC specialist instructed the pilot to contact Honolulu Air Route Traffic Control Center (ARTCC) on frequency 119.3.

At 2103, the pilot contacted the ARTCC specialist on duty and reported level at 11,000 ft msl.

At 2104, the ARTCC specialist asked if the pilot could climb to 13,000 ft msl, and the pilot responded that he could.

As the flight proceeded on an east-southeasterly heading and along the northern shoreline of the Island of Maui, it turned southbound along the predetermined flight route.

At 2108, as the flight continued on a southeasterly heading, the ARTCC specialist initially instructed the pilot to turn right to a heading of 180°, then to an amended heading of 200°, and the pilot acknowledged the 200° heading.

At 2109, as the flight continued on a 200° heading at 13,000 ft msl, the ARTCC specialist instructed the pilot to descend to 12,000 ft msl, and the pilot accepted.

At 2110, the ARTCC specialist instructed the pilot to descend to 8,000 ft msl, and the pilot acknowledged.

At 2112, the ARTCC specialist instructed the pilot to fly a heading of 180°, and he cleared the flight to fly direct to Tammi, the initial approach fix for the RNAV (GPS) 4 approach to MUE, and the pilot acknowledged the instructions.

At 2113:22, the ARTCC specialist contacted the pilot of N13GZ, asking him to verify that he was flying “direct to Tammi” as previously instructed.

At 2113:25, the pilot replied, in part: “Uhh, 13GZ is off navigation here… we’re gonna… we’re gonna give it a try.”

At 2113:32, the ARTCC specialist acknowledged the pilot’s last statement and instructed him to turn right to a 170° heading and to maintain 8,000 ft msl.

At 2113:43, a final radio transmission, believed to be from the accident pilot, is heard saying “Hang on.”

There were no further communications with the accident flight.

A witness who was flying a low-wing Piper PA-44 airplane from Hilo, Hawaii, to Honolulu reported seeing the accident airplane well above and to the north of his northwesterly flight path. He stated that, after the ARTCC specialist reported N13GZ to his 3 o’clock position at 12,000 ft msl, descending to 8,000 ft msl, he continued watching the lights of the airplane. He said that, as the airplane continued southbound, it began a right turn, then it entered a spiraling right descending turn, which steepened as the descent increased. The witness said that he watched the airplane continue to descend until it impacted the surface of the water. He added that, shortly after the airplane impacted the water, he lost sight of the airplane’s lights. The accident airplane was equipped with Automatic Dependent Surveillance–Broadcast (ADS– B), which provides aircraft position information via satellite navigation or other sensors and periodically broadcasts it, enabling the aircraft to be tracked. The information can be received by air traffic control ground stations as a replacement for secondary surveillance radar, as no
interrogation signal is needed from the ground.

According to archived FAA ADS-B data, after the airplane departed OGG, it initially proceeded north, then it turned eastbound, which is consistent with the Onohi Two standard instrument departure procedure. As the airplane neared the northeastern shores of Maui, while climbing to 11,000 ft msl, it eventually turned southbound along the Victor 11 airway. The ADS-B data eventually stopped near where the witness observed the accident airplane impact the water.

An alert notice (ALNOT) was issued by the FAA at 2127, and an extensive search was launched by the United States Coast Guard. During the search, portions of airplane wreckage were found floating near and in the vicinity of the last known location of the accident airplane. Neither the airplane nor its occupants have been located. The search was officially suspended on December 19, 2022, at 0955.

The airplane was equipped with a cockpit voice recorder (CVR) and a Dukane underwater acoustical beacon, as well as an Appareo Vision 1000 cockpit-mounted Airborne Image Recording System (AIRS).

The airplane wreckage sank in the open ocean waters of an area known as the Maui Channel, with an estimated water depth of 6,000 ft. Deep water search and recovery efforts are pending.