# NTSB LAX92LA278: Bell 47G5, N4798R, Mesa, AZ, July 4, 1992

- Type: NTSB accident investigation
- Classification: Accident · Minor injuries · Limited investigation · Final report
- Date: July 3, 1992, 21:14 local (Jul 4, 1992, 04:14 UTC)
- Place: Mesa, AZ
- Coordinates: 33.440025, -111.850418 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=33.4400&lon=-111.8504&mi=10
- Phase of flight: [Taxi](https://openairdocs.org/ntsb-phases/250) (OpenAirDocs' grouping)
- Highest injury: Minor injuries
- Injuries: 1 minor
- Status: Completed, report September 28, 1993
- Report: Approved by Office Director
- NTSB case key (mKey): 27674
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=LAX92LA278
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/27674/pdf
- Page: https://openairdocs.org/ntsb/LAX92LA278

## Probable cause

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.

## Sequence of events

In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf).

- Loss of engine power(partial) - nonmechanical, taxi - aerial
  - reason for occurrence undetermined (cause)
- Forced landing, descent - emergency
  - altitude - inadequate (contributing factor)
  - rotor rpm - inadequate, pilot in command (contributing factor)
  - remedial action - not possible, pilot in command (contributing factor)
- Hard landing, descent - emergency

## Analysis

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.

## Aircraft

- Registration: [N4798R](https://openairdocs.org/aircraft/N4798R), registered now, S/N 7925, built 1968 (OpenAirDocs)
- Reported make and model: BELL 47G5
- Registry model: [Bell 47G-5](https://openairdocs.org/model/bell-47g-5) (registry code 1181032) (OpenAirDocs)
- Registry engine: [Lycoming VO-435 series](https://openairdocs.org/engine/lycoming-vo-435-series) (registry code 41525, reciprocating) (OpenAirDocs)
- Category: Helicopter
- Serial number: 7925
- Engines: LYCOMING VO-435-B1A 260 horsepower reciprocating
- Damage: Destroyed
- Flight: Aerial application, Part 137
- Operator: Red Mountain Helicopters, Inc.
- Registered owner: Jack Sinton
- Airworthiness certificate: Special, Restricted (Special); Standard, Normal
- Last inspection: Unknown, January 2, 2000
- Departed: NONE
- Destination: NONE

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 31; commercial; airplane ratings: single-engine land; instrument ratings: helicopter; medical: class 2, valid medical--no waivers/lim.; seat: right; flight hours: 2,000 total

## Weather

- Conditions: Visual (VMC), Night/bright
- Wind: 340° at 4 knots
- Visibility: 30 statute miles
- Lowest ceiling: none
- Temperature: 97 °F, dew point -0 °F

## FAA reports on this event (1)

The FAA's own accident and incident reports, matched to the aircraft by N-number and date (OpenAirDocs).

- [Accident 19920703026479A](https://openairdocs.org/incident/19920703026479A), Jul 3, 1992: Bell 47G5, Mesa, AZ, Destroyed. Reported power droop on liftoff caused helicopter to settle hard to ground rotors destroyed aircraft.

## Other investigations on N4798R (2)

From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date, checked against the reported serial number, make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model.

- [NTSB LAX90DVM01](https://openairdocs.org/ntsb/LAX90DVM01), Nov 1, 1989: Bell 47G-5 (N4798R), Guadalupe, CA, substantial damage. Probable cause: THE PILOT'S FAILURE TO MAINTAIN SUFFICIENT CLEARANCE ALLOWING THE AIRCRAFT TO COLLIDE WITH A WOODEN POWER POLE. CONTRIBUTING TO THE ACCIDENT WAS THE SUNGLARE WHICH INHIBITED THE PILOT'S VISION.
- [NTSB LAX73FUD02](https://openairdocs.org/ntsb/LAX73FUD02), Jul 21, 1972: Bell 47G-5 (N4798R), Santa Mnica, CA, substantial damage

From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date, checked against the reported serial number, make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model.

---
OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.