Hughes 269C accident near Rialto, California, May 23, 1990
On May 23, 1990 at about 6:10 pm local time, a Hughes 269C (helicopter), registered N7441F, was substantially damaged in an accident near Rialto, California (Rialto airport). It was a flight of an unrecorded kind under general aviation rules (Part 91). No one was hurt; 1 person was on board or involved. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
IMPROPER MAINTENANCE PROCEDURE BY MAINTENANCE PERSONNEL TO TROUBLESHOOT A REPORTED DEFICIENCY AND THE PILOT'S DECISION TO DEMONSTRATE THE VIBRATION, EXCEEDING THE DESIGN LIMITS OF THE HELICOPTER AND INDUCING GROUND RESONANCE. CONTRIBUTING TO THE ACCIDENT WAS THE LOW NITROGEN CHARGE OF THE LANDING GEAR DAMPERS.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- May 23, 1990 · about 6:10 pm local time
- Place
- Rialto, California · Rialto · map
- Type
- Accident
- Injuries
- No one was hurt; 1 person was on board or involved.
- Weather
- visual conditions (good weather)
- Aircraft
- Hughes 269C · all 269Cs on the register
- Registration
- N7441F · no longer on the register · serial 460487
- Damage
- Substantial damage
- Flight
- Flight of an unrecorded kind · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
THE HELICOPTER ENCOUNTERED GROUND RESONANCE DURING A MAINTENANCE TEST FLIGHT. THE CFI NOTICED AN UNUSUAL VIBRATION DURING STUDENT TRAINING. THE PILOT SUSPENDED THE TRAINING AND INFORMED MAINTENANCE. THE PILOT THEN ATTEMPTED TO DUPLICATE THE VIBRATION FOR ONE OF THE MAINTENANCE MECHANICS. AFTER TWO UNSUCCESSFUL ATTEMPTS, THE PILOT LANDED THE HELICOPTER ON A SLIGHT SLOPE. AFTER ONE SKID TOUCHED DOWN, THE HELICOPTER BEGAN TO VIBRATE. THE PILOT REDUCED THE THROTTLE AND THE VIBRATION BECAME MORE SEVERE. ACCORDING TO THE PILOT, THE HELICOPTER BEGAN TO DISINTEGRATE.
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; single-engine land; instructor: airplane single-engine; instructor: helicopter; instrument: airplane; instrument: helicopter; rotorcraft: helicopter
- Flight time: 6,200 hours in all; 184 in this make and model; 120 in the last 90 days; 100 in the last 30 days; 5,873 as pilot in command; 430 on instruments
- Medical certificate: Class 2 (valid medical--no waivers/lim.)
- Seat: rgt
The aircraft
- Airframe total time: 2,366 hours
- Last inspection: 100-hour inspection, April 22, 1990; 87 hours since
- Maximum gross weight: 2,050 lb
- Seats: 2
- Landing gear: fixed
- Engine: Lycoming HIO-360-D1A (piston); 0 hours total
The flight
- Flight plan: not recorded
- Runway 0
Weather at the time
- Light: daylight
- Wind: from 270° at 5 knots
- Visibility: 20 statute miles
- Sky: clear
- Temperature: 0°F (-18°C), dew point 0°F (-18°C)
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.