Beech B90 accident near Mokuleia, Hawaii, May 23, 1999
On May 23, 1999 at about 5:30 am local time, a Beech B90, registered N301DK, was destroyed in an accident near Mokuleia, Hawaii (Dillingham Airfld Airport). It was a skydiving flight under general aviation rules (Part 91). 1 person was killed. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
The pilot's incapacitation due to the effects of hypoxia from repeated flights to altitudes above 18,000 feet msl without supplemental oxygen.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- May 23, 1999 · about 5:30 am local time
- Place
- Mokuleia, Hawaii · Dillingham Airfld Airport · map
- Type
- Accident
- Injuries
- 1 person was killed.
- Weather
- visual conditions (good weather)
- Aircraft
- Beech B90 · all B90s on the register
- Registration
- N301DK · registry record · serial LJ-372
- Damage
- Destroyed
- Flight
- Skydiving flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
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.
The complete narrative as the NTSB published it. The NTSB's docket holds the report as a PDF and any photographs, statements and other documents from the investigation.
The factual record from the NTSB's investigation tables, in plain English
Pilot
- Certificate: airline transport pilot
- Ratings: multi-engine land; multi-engine sea; single-engine land; single-engine sea; instrument: airplane
- Flight time: 2,000 hours in all
- Medical certificate: Class 2 (valid medical--no waivers/lim.)
- Seat: left
The aircraft
- Last inspection: continuous airworthiness programme, May 20, 1999
- Maximum gross weight: 9,650 lb
- Seats: 1
- Landing gear: retractable
- Engine: P&W PT6A-28 (turboprop); 0 hours total
The flight
- Departed from: HDH at 5:15 am
- Flight plan: none
- Runway 0
Weather at the time
- Light: dusk
- Wind: from 040° at 7 knots
- Visibility: 10 statute miles
- Sky: broken clouds at 5,500 ft; clear
- Temperature: 79°F (26°C), dew point 64°F (18°C)
- Altimeter: 30.00 inHg
- Observation at 4:53 am from HNL, 25 miles away
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Crew | 1 |
Documents from the investigation the NTSB's docket: the evidence folder behind the report
The docket, the folder of records gathered during an investigation (maintenance records, photographs, witness statements, examinations), has not been read from the NTSB for this case yet; the list appears here once it has. Open the docket at the NTSB.
Everything on this page comes from the NTSB's public records. The narrative, probable cause and findings are the NTSB's own words; the coded tables behind the report are written out in plain English, with pilots' ages, home towns and medical details left out. The documents and photographs are the NTSB's docket, shown as the NTSB released them. This site's own text never names anyone involved. A preliminary report can change; the final report usually follows one to two years later, and the page is refreshed when it does.
