Bell 47G5 accident near Mesa, Arizona, July 4, 1992
On July 4, 1992 at about 4:14 am local time, a Bell 47G5 (helicopter), registered N4798R, was destroyed in an accident near Mesa, Arizona. It was an aerial application (crop spraying) flight under agricultural flying rules (Part 137). 1 person had minor injuries. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
A PARTIAL LOSS OF ENGINE POWER DUE TO UNKNOWN REASON (S). FACTORS IN THIS ACCIDENT WERE 1) LOW ALTITUDE WHEN THE PARTIAL LOSS OF POWER OCCURRED 2) LOW ROTOR RPM AS A RESULT OF THE LOSS OF POWER, AND 3) THE PILOT NOT BEING ABLE TO TAKE REMEDIAL ACTION DUE TO THE LOW ALTITUDE AND ROTOR RPM.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- July 4, 1992 · about 4:14 am local time
- Place
- Mesa, Arizona · map
- Type
- Accident
- Injuries
- 1 person had minor injuries.
- Weather
- visual conditions (good weather)
- Aircraft
- Bell 47G5 · all 47G5s on the register
- Registration
- N4798R · registry record · serial 7925
- Damage
- Destroyed
- Flight
- Aerial application (crop spraying) flight · agricultural flying rules (Part 137)
The NTSB's narrative final · quoted from the NTSB record
ACCORDING TO A WITNESS, THE PILOT WAS PERFORMING A TAKEOFF AFTER THE HELICOPTER HAD BEEN LOADED WITH ABOUT 60 GALLONS OF INSECTICIDE. THE HELICOPTER ATTAINED AN ALTITUDE OF ABOUT 50 TO 60 FEET ABOVE THE GROUND WHEN THE WITNESS OBSERVED THE TAIL ROTOR MOVE LATERALLY ABOUT 4 TO 5 FEET. THE WITNESS SAID HE SAW THE AIRCRAFT SETTLE TO THE GROUND AND LAND HARD. HE SAID HE IMMEDIATELY ASKED THE PILOT WHAT HAPPENED. THE PILOT REPORTEDLY TOLD THE WITNESS THAT HE HAD A 'POWER DROOP.' THE CAUSE OF THE PARTIAL LOSS OF POWER WAS NOT DETERMINED.
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: commercial pilot
- Ratings: single-engine land; instrument: helicopter; rotorcraft: helicopter
- Flight time: 2,000 hours in all
- Medical certificate: Class 2 (valid medical--no waivers/lim.)
- Seat: rgt
The aircraft
- Last inspection: inspection type not recorded, January 2, 2000
- Maximum gross weight: 2,850 lb
- Seats: 2
- Landing gear: fixed
- Engine: Lycoming VO-435-B1A (piston); 0 hours total
- Operator: Red Mountain Helicopters, INC.
The flight
- Departed from: NONE at 4:13 am
- Destination: NONE
- Flight plan: none
- Runway 0
Weather at the time
- Light: night, bright
- Wind: from 340° at 4 knots
- Visibility: 30 statute miles
- Sky: clear
- Temperature: 97°F (36°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.
Other NTSB records under N4798R the same tail number, which may have belonged to a different aircraft at the time
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.