Bell 47G N25LB

Summary

On 8 June 2016 at about 17:05 local time, a Bell 47G registered N25LB was involved in an accident near Hastings, Minnesota, 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

8 June 2016 at 17:05

Classification

Accident

Location

Hastings, Minnesota, United States

Coordinates

44.6519, -92.8661

Aircraft

Bell 47G

Registration

N25LB

Category

Helicopter

Year built

1978

Engines

1

Operator

Not recorded

Operating rule

Part 137: Agricultural

Purpose of flight

Aerial Application

Phase of flight

Not recorded

Route

Le Sueur → Hastings

Aircraft damage

Substantial

Weather

VMC

Light

Day

NTSB number

GAA16CA293

Nobody was injured.

The pilot's failure to attain a positive rate of climb during takeoff from a service truck, which resulted in an impact with terrain and substantial damage to the tail boom and fuselage.

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

Read the full NTSB narrative

The pilot reported that he was conducting aerial agricultural operations in a helicopter and that he landed on the bed of the service truck to reload with insecticide and fuel. The pilot further reported that he began to lift off and during the transition to forward flight he pitched the helicopter forward to gain airspeed, but helicopter continued to descend. The pilot reported that he "never gained lift from the ground effect" and subsequently impacted the terrain. The helicopter sustained substantial damage to the tail boom and fuselage. The pilot reported there were no preimpact mechanical failures or malfunctions with the airframe or engine that would have precluded normal operation. FAA Helicopter Flying Handbook Chapter 2 "Aerodynamics" defines "In Ground Effect (IGE)" as the increased efficiency of the rotor system caused by interference of the airflow when near the ground. The air pressure or density is increased, which acts to decrease the downward velocity of air. Ground effect permits relative wind to be more horizontal, lift vector to be more vertical, and induced drag to be reduced. These conditions allow the rotor system to be more efficient. Maximum ground effect is achieved when hovering over smooth hard surfaces. When hovering over surfaces as tall grass, trees, bushes, rough terrain, and water, maximum ground effect is reduced. Rotor efficiency is increased by ground effect to a height of about one rotor diameter (measured from the ground to the rotor disk) for most helicopters.

Quoted verbatim from the NTSB record.