Bell 47G-3B-1 N83702

Summary

On 6 August 2013 at about 15:30 local time, a Bell 47G-3B-1 registered N83702, operated by Speas Aviation Inc, was involved in an accident near Vinton, Iowa, United States. One person was on board and nobody was injured. The aircraft was substantially damaged. The NTSB has published a probable cause for this accident; it is quoted in full below.

Date

6 August 2013 at 15:30

Classification

Accident

Location

Vinton, Iowa, United States

Coordinates

42.1767, -91.9808

Aircraft

Bell 47G-3B-1

Registration

N83702

Category

Helicopter

Year built

1966

Engines

1

Operator

Speas Aviation Inc

Operating rule

Part 137: Agricultural

Purpose of flight

Aerial Application

Phase of flight

Not recorded

Route

Vinton → Vinton

Aircraft damage

Substantial

Weather

VMC

Light

Day

NTSB number

CEN13LA463

Nobody was injured.

The pilot's operation of the helicopter at high gross weight and high density altitude while still in ground effect, which reduced the efficiency of the rotor system and the amount of lift produced, which resulted in a collision with terrain. Contributing to the accident was the pilot's decision to continue the flight after the first indication of reduced performance.

Quoted verbatim from the NTSB record. This site does not paraphrase or interpret it.

Read the full NTSB narrative

After reloading the helicopter with agricultural spray product, the pilot flew the helicopter off of the loading truck bed for the aerial application flight. Shortly after takeoff, while operating the helicopter at an altitude of about 10 feet above the ground, the pilot noted a decrease in rotor rpm and made a precautionary landing in tall grass. When he noted no anomalies after the landing, the pilot decided to continue the flight. He took off in the helicopter again and flew for about 100 yards before he again noted a decrease in rotor rpm. The helicopter descended and struck the ground with the tail low, which resulted in substantial damage to the tail rotor and tailboom. An examination of the airframe and engine did not reveal any mechanical malfunctions or failures that would have precluded normal operation. The helicopter was operating above tall grass and crops while still in ground effect, which likely reduced the efficiency of the rotor system and decreased the amount of lift produced as compared to operating over bare ground. In addition, the helicopter was loaded to within 16 pounds of its maximum gross weight and was operating at a density altitude of about 2,800 feet, which likely also contributed to the decreased performance of the helicopter.

Quoted verbatim from the NTSB record.