ATL97LA088

NTSB accident investigation · Air Tractor AT-402B · Ridgely, TN · June 23, 1997

Accident · No injuriesLimited investigationFinal report
Date
June 23, 1997, 16:30 local (21:30 UTC)
Place
Ridgely, TN
Injuries
1 uninjured
Damage
Substantial damage
Phase of flight
Initial climb
Aircraft
N6128WAir Tractor AT-402B
Weather
Visual (VMC) · Day
Status
Completed · report September 5, 1997
Report
Approved by Office Director
FAA report
19970623015429A
Case key
3862

From the NTSB’s public API. By law, NTSB reports can’t be used as evidence in lawsuits over the accident.

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Probable cause

The pilot's inadequate preflight planning in that he failed to account for the high temperature and high density altitude, which resulted in an aerodynamic stall and loss of control. Factors were the tall crops and the ditch.

Sequence of events

NTSB’s coding before 2008: each occurrence and phase of flight, and the causes and factors under it. The codes are defined in NTSB’s coding manual.

On ground/water encounter with terrain/waterTakeoff - initial climb
Preflight planning/preparation - inadequatePilot in commandCause
Performance data - not obtainedPilot in commandCause
Weather condition - temperature,highFactor
Weather condition - high density altitudeFactor
Stall - inadvertentPilot in command
Terrain condition - cropFactor
Terrain condition - ditchFactor

Analysis

According to the pilot, after taking off from the grass strip, for the fourteenth or fifteenth time that day, with the same load and fuel quantity, he noticed that, after lift off, the 'airplane did not seem to accelerate like normal and began to sink'. He stated he then attempted to dump the 3100 pounds of ammonium nitrate he was carrying. Subsequently, after the doors opened, the airplane stalled, and the airplane collided with the ground; a corn field with plants about six feet tall. The pilot stated that 'before he could reach the power lever, the airplane started turning slightly to the right, and then the left landing gear failed'. No mechanical problems were reported by the pilot. The pilot stated that he believed the light and variable wind and the high temperature contributed to the failure of the airplane to climb. The ambient conditions, at the time of the accident, were the high temperature, high density altitude, and high gross weight of the airplane.

Factual narrative

On June 23, 1997, at 1630 central daylight time, an Air Tractor, AT-402B, N6128W, collided with the ground during takeoff from Dewdrop Airstrip, Ridgely, Tennessee. The aerial application flight was being conducted under the provisions of Title 14 CFR Part 137 with no flight plan filed. Visual meteorological conditions prevailed. The commercial pilot was not injured, and the airplane sustained substantial damage. The flight was originating at the time of the accident.

According to the pilot, after taking off from the grass strip, for the fourteenth or fifteenth time that day, with the same load and fuel quantity, he noticed the "airplane lifted off to about fifteen to twenty feet above the ground, and that the airplane did not seem to accelerate like normal and began to sink". He stated that he then attempted to dump the 3100 pounds (lb.) of ammonium nitrate he was carrying. Subsequently, after the doors opened, the airplane collided with the ground; a corn field with plants about six feet tall. The pilot stated that "before he could reach the power lever, the airplane started turning slightly to the right, and then the left landing gear failed". The propeller and fuselage collided with the ground, and the airplane came to rest, facing south, straddling a ditch, with its tail into a street. No mechanical problems were reported by the pilot. The pilot stated that he believed the light and variable wind and the high temperature contributed to the failure of the airplane to climb. The density altitude could not be calculated, whereas, the altimeter setting was not available.

According to the FAA, the airplane was carrying 3100 lb. of ammonium nitrate and 120 pounds of fuel. The maximum quantity for both are 3200 lb. and 176 lb., respectively.

The pilot reported that the left wing was damaged, the left landing gear was detached, the right landing gear was bent, and the tubing was torn and bent at the landing gear attachment points and the side of the hopper. He also stated that the hopper was damaged, the engine mounts were bent, and the propeller and engine were damaged.

Aircraft

Registration
N6128W
Reported as
Air Tractor AT-402B
Category
Airplane
Serial number
402B-1002
Airframe hours
1,324
Engine
P&W PT6A-15AG, 680 horsepower, turbo prop
Damage
Substantial damage
Flight
Aerial application · Part 137
Registered owner
Rainey Aerial Ag Service, Inc.
Airworthiness certificate
Special, Restricted (Special)
Last inspection
100 hour · May 20, 1996 · 116 hours before
Departed
PVT
Airport
PVT · Dewdrop Strip, runway 27, 2,100 × 100 ft, grass/turf

Matched to the registry by N-number and the event date; the registry’s history has gaps, so older matches can be wrong. Compare the reported make and model.

Flight crew

As NTSB recorded them. NTSB leaves out names.

Role
Pilot
Age
34
Certificate
Commercial
Airplane ratings
Single-engine land
Instrument ratings
Airplane
Medical
Class 2, Valid Medical--no waivers/lim.
Seat
Center
Flight hours
9,769 total · 5,969 in this make and model · 9,697 as pilot in command · 353 in the last 90 days · 109 in the last 30 days · 9 in the last 24 hours

Weather

Conditions
Visual (VMC) · Day
Wind
220° at 4 knots
Visibility
10 statute miles
Lowest ceiling
None
Temperature
91 °F, dew point 73 °F
Observed at
DYR, 15 nm away

FAA reports on this event · 1

The FAA’s own accident and incident reports, matched to the aircraft by N-number and date.