Robinson R22B accident near Honolulu, Hawaii, October 4, 1991
On October 4, 1991, a Robinson R22B (helicopter), registered N900AB, was substantially damaged in an accident near Honolulu, Hawaii. It was an instructional flight under general aviation rules (Part 91). No one was hurt; 2 people were on board or involved. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
THE IMPROPER USE OF THE FLIGHT CONTROLS BY THE INSTRUCTOR PILOT ND THE FAILURE TO MAINTAIN PROPER ROTOR RPM.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- October 4, 1991
- Place
- Honolulu, Hawaii
- Type
- Accident
- Injuries
- No one was hurt; 2 people were on board or involved.
- Weather
- visual conditions (good weather)
- Aircraft
- Robinson R22B · all R22Bs on the register
- Registration
- N900AB · no longer on the register · serial 1455
- Damage
- Substantial damage
- Flight
- Instructional flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
ACCORDING TO STATEMENTS FROM BOTH THE INSTRUCTOR AND STUDENT, THE FLIGHT WAS PRACTICING PINNACLE APPROACHES IN A MOUNTAINOUS AREA. THE INSTRUCTOR SAID HE PERFORMED A HIGH RECONNAISSANCE OF THE SPOT, AND THEN THE FLIGHT ENCOUNTERED A DOWN DRAFT DURING THE FINAL APPROACH TO THE PEAK. THE INSTRUCTOR SAID HE PERFORMED A RIGHT PEDDLE TURN TO FLY DOWN THE SLOPE OVER A STREAM. THE LOW ROTOR HORN CAME ON AND THE INSTRUCTOR SAID HE ATTEMPTED TO GET THE ROTOR RPM BACK INTO THE GREEN ARC BUT BEFORE HIS CONTROL INPUTS WERE EFFECTIVE THE MAIN ROTOR BLADE COLLIDED WITH TREES ON THE STREAM BANK AND THE HELICOPTER CRASHED INTO THE WATER.
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: flight instructor, commercial pilot
- Ratings: instructor: helicopter; rotorcraft: helicopter
- Flight time: 1,725 hours in all; 1,200 in this make and model; 500 on instruments
- Medical certificate: Class 2 (valid medical--no waivers/lim.)
- Seat: unk
The aircraft
- Last inspection: inspection type not recorded, January 2, 2000
- Maximum gross weight: 1,350 lb
- Seats: 2
- Landing gear: fixed
- Engine: Lycoming O-320 (piston); 0 hours total
- Operator: Makani Helicopters, INC.
The flight
- Flight plan: none
- Runway 0
- A second pilot was aboard
Weather at the time
- Light: daylight
- Wind: from 080° at 10 knots
- Visibility: 20 statute miles
- Sky: scat at 3,000 ft
- Temperature: 84°F (29°C), dew point 0°F (-18°C)
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Crew | 2 |
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.