Beech D18S accident near Hilo, Hawaii, November 10, 1991
On November 10, 1991 at about 6:50 pm local time, a Beech D18S, registered N4193, was substantially damaged in an accident near Hilo, Hawaii (Hilo International airport). It was a flight of an unrecorded kind under charter and air-taxi rules (Part 135). No one was hurt; 11 people were on board or involved. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
THE AIRCRAFT'S LACK OF SINGLE ENGINE PERFORMANCE TO MAINTAIN ALTITUDE AFTER THE ENGINE LOST POWER. FACTORS RELATED TO THE ACCIDENT WERE: DISPLACEMENT/MECHANICAL INTERFERENCE WITHIN THE ACCESSORY DRIVE GEAR SYSTEM OF THE LEFT ENGINE, FAILURE OF THE LEFT ENGINE ACCESSORY DRIVE GEAR SHAFT, AND THE FAA'S INADEQUATE CERTIFICATION/APPROVAL OF THE OPERATOR, IN ORDER TO ASSURE COMPLIANCE WITH 14 CFR 135 CONCERNING THE ENGINE-OUT CAPABILITY.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- November 10, 1991 · about 6:50 pm local time
- Place
- Hilo, Hawaii · Hilo International · map
- Type
- Accident
- Injuries
- No one was hurt; 11 people were on board or involved.
- Weather
- visual conditions (good weather)
- Aircraft
- Beech D18S · all D18Ss on the register
- Registration
- N4193 · no longer on the register · serial A980
- Damage
- Substantial damage
- Flight
- Flight of an unrecorded kind · charter and air-taxi rules (Part 135)
The NTSB's narrative final · quoted from the NTSB record
ABT 45 MI FM LNDG, THE L ENG RPM BGN TO FLUCTUATE, THEN AT ABT 15 MI FM LNDO, IT LOST POWER ALTOGETHER. THE PLT SAID THE ACFT WOULD NOT MAINT ALTITUDE. UNABLE TO RCH THE RWY, HE DITCHED THE ACFT IN HILO BAY ABT 1/4 MI FM SHORE & 1.5 MI FM THE ARPT. AFTER RETRIEVAL, THE ACFT & L ENG WERE EXAMINED. THE ACCESSORY GEAR DRIVE SHAFT WAS FND TO HAVE FAILED IN TORSIONAL OVERLOAD. ON THE INSIDE OF THE CASE, AN AREA OF GOUGING & ABRASION WAS FND DRCTLY IN FNT OF THE STARTER GEAR. (THE LEFT MAG, FUEL PUMP & PROP GOVERNOR WERE DRIVEN BY THE ACCESSORY DRIVE GEAR.) DEEP IMPRESSIONS WERE NOTED ON ABT 70% OF THE GEAR TEETH, WITH MTRL DISPLACEMENT & GOUGING EVIDENT. THERE WAS EVIDENCE THAT THE COLLECTOR DRIVE FLOATING GEAR MAY HAVE MOVED FORWARD & HAD CONTACTED THE ENG CASE. ALSO, THERE WAS EVIDENCE OF MECHANICAL INTERFERENCE WITHIN THE ACCESSORY DRIVE GEAR SYS. THE ACFT GROSS WT AT THE TIME OF THE ACDNT WAS ABOUT 9108 LBS.
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; instrument: airplane
- Flight time: 18,579 hours in all; 323 in this make and model; 180 in the last 90 days; 59 in the last 30 days; 10,712 as pilot in command; 1,031 on instruments
- Medical certificate: Class 2 (valid medical--w/ waivers/lim.)
- Seat: left
The aircraft
- Airframe total time: 19,936 hours
- Last inspection: 100-hour inspection, October 28, 1991; 35 hours since
- Maximum gross weight: 10,200 lb
- Seats: 11
- Landing gear: retractable
- Engine: P&W R-985-AN14B (piston); 0 hours total
- Operator: Tomy International
The flight
- Departed from: HNL Honolulu HI at 5:00 pm
- Destination: ITO Hilo HI
- Flight plan: VFR
- Runway 8, 9,800 ft by 150 ft
Weather at the time
- Light: daylight
- Wind: from 260° at 10 knots
- Visibility: 15 statute miles
- Sky: broken clouds at 28,000 ft; scat at 2,300 ft
- Temperature: 79°F (26°C), dew point 70°F (21°C)
- Altimeter: 30.00 inHg
- Observation at 6:44 pm from ITO, 1 miles away
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Crew | 1 | |||
| Passengers | 10 |
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.