# NTSB LAX99LA190: Beech B90, N301DK, Mokuleia, HI, May 23, 1999 - Type: NTSB accident investigation - Classification: Accident · Fatal · Limited investigation · Final report - Date: May 22, 1999, 19:30 local (May 23, 1999, 05:30 UTC) - Place: Mokuleia, HI - Coordinates: 21.569091, -158.119247 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=21.5691&lon=-158.1192&mi=10 - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Highest injury: Fatal - Injuries: 1 fatal - Status: Completed, report December 4, 2000 - Report: Approved by Office Director - NTSB case key (mKey): 46389 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=LAX99LA190 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/46389/pdf - Page: https://openairdocs.org/ntsb/LAX99LA190 ## Probable cause The pilot's incapacitation due to the effects of hypoxia from repeated flights to altitudes above 18,000 feet msl without supplemental oxygen. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - In flight collision with terrain/water, descent - oxygen system - not installed (cause) - in-flight planning/decision - inadequate, pilot in command (cause) - proper altitude - exceeded, pilot in command (cause) - incapacitation(anoxia/hypoxia), pilot in command (cause) ## Analysis Following the 12th sport parachute jump of the day, which occurred after sunset, ground witnesses observed the airplane descend into the ocean in a left wing low, nose down attitude. They did not hear the engines sputtering or popping, or see the airplane make any erratic movements during its descent. Skydivers indicated that the two previous flights had been conducted at altitudes of at least 18,000 feet, and the accident flight and subsequent jump were made at 20,000 feet. During this final jump flight, one of the skydivers stated he had a hard time breathing and felt nauseous. The skydivers also noted that the pilot was unable to maintain a steady course and did not respond well to minor course corrections. No supplemental oxygen was found onboard the airplane during the recovery or subsequent inspection phases of the investigation. No skydiver observed the pilot using supplemental oxygen. The airplane manufacturer noted that the pressurization system would have been rendered inoperable due to a non-sealed cockpit door. Hypoxia is defined as a physiological condition where a person is bereft of needed oxygen. Judgment is poor and reaction time delayed. Total incapacitation coupled with a loss of consciousness can occur with little or no warning. The airframe, engines, and propellers were examined with no preexisting impact anomalies found. ## Factual narrative HISTORY OF FLIGHT On May 22, 1999, at 1930 hours Hawaiian standard time, a Beech B90, N301DK, crashed into the Pacific Ocean, near Dillingham Airfield Airport, Mokuleia, Hawaii. The airplane, operated by Pacific International Skydiving Center under 14 CFR Part 91, was destroyed in the impact sequence and sank to a depth of approximately 156 feet of water. The airline transport pilot, the sole occupant, was not found and presumed to have received fatal injuries. Visual meteorological conditions existed for the skydiving flight and no flight plan was filed. The flight originated from the Dillingham airport, the day of the accident, about 1905 to transport skydivers to jump altitude. The accident location is about 1.5 miles northeast of the approach end of Dillingham's runway 26, which runs approximately parallel to the shoreline. Federal Aviation Administration (FAA) inspectors interviewed a number of witnesses who either observed the sequence of events or had knowledge of the flight. Several of the witnesses said that the pilot's practice, especially with high altitude jumps, was to land before the jumpers had reached the ground. The witnesses first observed the airplane, as it appeared to be maneuvering toward runway 26 for landing; the location of the airplane and its maneuvers were similar to other approaches made by the pilot that day. The only unusual aspect reported by the witnesses was that the airplane's altitude above the water was lower than on previous flights. Some witnesses estimated the height above water as 200 feet. The airplane was in a turn toward the southwest when the nose dropped and it flew into the water. Some witnesses described the bank angle as steep, while others reported it as normal. The witnesses who observed the airplane descend into the ocean recalled hearing the engines, and stated that there had been a high-pitched sound, but that the engines were not sputtering or popping. They also stated that the airplane did not look out of control, but rather that it was in a steady descent, with no erratic movements evident. An FAA inspector reported that this was the 11th flight of the day. The inspector interviewed two of the skydivers who jumped from the accident airplane, on previous flights, and on the accident flight. Both skydivers stated that the accident flight was made to 20,000 feet, and that two other flights were done to altitudes of at least 18,000 feet. Neither skydiver reported that the pilot was using supplemental oxygen during these flights. One of the skydivers stated that on the accident flight, the jump was made after sunset and was performed without any lighting devices. He also stated that he felt sick and was having a hard time breathing because they had been at 20,000 feet for an unusually long time prior to making the jump. He further stated that a couple of the skydivers had paid the pilot in order to get him to climb to that altitude for the last jump. Other skydivers asked the pilot prior to exiting the airplane on the accident flight at 20,000 feet, if he was okay. They noted that he had been unable to maintain a steady course, and he did not respond well to minor course corrections. The FAA inspector further noted that supplemental oxygen was not found onboard the airplane during the recovery. A compilation of witnesses on the ground agreed that the accident happened about 20-25 minutes after sunset. From their various locations they had all been watching a biplane performing aerobatics when they noticed the accident airplane. They also noticed skydivers in the air with no lighting devices. Witnesses thought this was unusual because it was their experience when the parachutists jump after sunset they have lights on. According to Federal Aviation Regulations (FAR) Part 105.33, each person that jumps between sunset and sunrise should be equipped with a means of producing light that is visible for at least 3 statute miles. According to the inspector, on the accident flight the pilot had not made any of the required radio calls to Air Traffic Control, which is required under 14 CFR Part 105.14. The inspector further noted that a review of the recorded radar data for the area disclosed that the airplane's transponder had not been turned on. According to the Chart Supplement for the Pacific region, parachute jumps may be made at Dillingham airfield up to 16,000 feet without filing a NOTAM (appended to report). PERSONNEL INFORMATION A review of the FAA Airman Certification records disclosed that the pilot held an airline transport pilot certificate with a single and multiengine land airplane rating. In addition, he held commercial pilot privileges for single and multiengine airplane sea. The most recent second-class medical certificate was issued to the pilot on May 21, 1998, and contained no limitations. The pilot's personal flight records were not located. AIRCRAFT INFORMATION On May 20, 1999, the Pratt and Whitney PT6A-20 engines installed on the airplane were removed and two Pratt and Whitney PT6A-28 engines were installed in accordance with a Supplemental Type Certificate (STC). Prior to installation of the engines, an overhauled propeller overspeed governor was installed. A flight test was conducted on May 21, 1999, with no discrepancies noted. Later that evening the airplane was flown back to it's home base. TESTS AND RESEARCH Pavsek and Associates recovered the wreckage on May 27 and May 28, 1999. The airframe and engines were examined on May 29, 1999, by representatives from Raytheon Aircraft and United Technologies Pratt and Whitney Engines - Canada, at Rotor Wing Hawaii, Inc., Honolulu, Hawaii. A representative from Hartzell Propeller, at the same location, examined the propellers on July 26, 1999. All the examinations took place under the supervision of FAA inspectors. The airframe examination revealed no preexisting structural or airplane system anomalies. The manufacturer reported that there was no supplemental oxygen found onboard the airplane during the recovery or subsequent inspection phases of the investigation. He further noted that the configuration of the airplane, a non-sealed cabin door, would have rendered the pressurization system inoperable. Flight control continuity was established to each wing. The control cable ends exhibited "broomstrawing" and "necking at the ends of the individual strands." The landing gear and flaps were found to be in the retracted position. The pilot's seat was found attached to the seat tracks, with a portion of the cabin floor remaining attached to the seat tracks. The seat belt was found fastened, with localized stretching of the webbing. The shoulder harness was not fastened. The engine examinations revealed no preexisting impact anomalies. Both engines displayed rotational signatures on their internal components that the manufacturer's representative stated was consistent with both engines being under power at impact. According to the manufacturer, the propeller examinations revealed "severe" symmetrical bending of the propeller blades. There were no indications that the propellers were in the feathered positions (not generating thrust). It was further noted by the manufacturer's representative that there were gouges on the cylinders walls, which could only occur if the piston was in a forward operating range exposing the cylinder. No discrepancies were noted with the propellers. The Safety Board's Materials Laboratory examined the annunciator panel and aft elevator down bracket with two sections of cable. The light bulb filaments were examined with an optical stereomicroscope. The glass envelopes on all the bulbs were found intact, but several of the filaments within the various bulbs were fractured. No evidence of filament stretching was found on any of the bulbs. The elevator down bracket was found fractured and the exterior surface ## Aircraft - Registration: [N301DK](https://openairdocs.org/deregistered/N301DK-1999-08-13), registration cancelled 1999-08-13, S/N LJ-372 (OpenAirDocs) - Reported make and model: Beech B90 - Registry model: [Beech B90](https://openairdocs.org/model/beech-b90) (registry code 1152912) (OpenAirDocs) - Category: Airplane - Serial number: LJ-372 - Engines: P&W PT6A-28 550 horsepower turbo prop - Damage: Destroyed - Flight: Skydiving, Part 91 - Operator: Pac Int'L Skydiving Center - Registered owner: Pac Int'L Skydiving Center - Airworthiness certificate: Standard, Normal - Last inspection: Continuous airworthiness, May 20, 1999 - Departed: HDH - Airport: HDH, Dillingham Airfld Airport ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 44; airline transport; airplane ratings: single-engine sea, multi-engine sea, multi-engine land, single-engine land; instrument ratings: airplane; medical: class 2, valid medical--no waivers/lim.; seat: left; flight hours: 2,000 total ## Weather - Conditions: Visual (VMC), Dusk - Wind: 40° at 7 knots - Visibility: 10 statute miles - Lowest ceiling: 5,500 ft broken - Temperature: 79 °F, dew point 64 °F - Altimeter: 30.00 inHg - Observed at: HNL, 25 nm away ## FAA reports on this event (1) The FAA's own accident and incident reports, matched to the aircraft by N-number and date (OpenAirDocs). - [Accident 19990522023949A](https://openairdocs.org/incident/19990522023949A), May 22, 1999: Beech B90, Mokuleia, HI, Destroyed, 1 fatal. (.19) On may 22, 1999, at 1930 hours hawaiian standard time, a Beech B90, N301DK, crashed into the pacific ocean under unknown circumstances, near dilligham… From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date, checked against the reported serial number, make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model. --- OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.