Pilot Debrief

AIR TRACTOR INC AT 402A near Shaw, MS — 2017-08-21

Final reportERA17LA286
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Date
2017-08-21
Location
Shaw, MS, USA
Airport
1MS0
Aircraft
AIR TRACTOR INC AT 402A
Registration
N247LA
Category
Airplane
Highest injury
Minor
Fatalities
0
Phase of flight
Takeoff roll

Probable cause

The pilot’s decision to attempt takeoff at high gross weight, in high density altitude conditions, and with insufficient runway length. Contributing to the accident was the pilot’s inadequate preflight planning.

NTSB narrative

The pilot was departing on an agricultural application flight from a 2,300-ft-long runway. When the airplane reached the end of the runway, the pilot could "feel that the airplane did not want to fly." The pilot extended the flaps, then dumped the spray load that was in the airplane’s hopper tank in an attempt to become airborne; however, the airplane continued off the end of the runway, crossed a drainage ditch, and came to rest in a bean field, resulting in substantial damage. The airplane’s hopper was loaded with about 3,400 lbs of a mixture of herbicide and other chemicals, which exceeded the hopper’s placarded limitation of 3,250 lbs. The airplane’s estimated weight at the time of the accident was 1,864 lbs higher than the manufacturer’s published gross weight and about 264 lbs more than field experience showed could be carried safely with adequate margins of performance and structural strength. Calculations by the airplane manufacturer using takeoff data of a similar airplane from a previous company test program indicated a takeoff ground roll distance of about 2,322 ft. Given the density altitude about the time of the accident, the airplane’s takeoff distance would have been increased by 24%, and there would have been an 18% decrease in its rate of climb. No preimpact failures or malfunctions were discovered that would have precluded normal operation. Despite the numerous indicators that the takeoff conditions were marginal, such as the high air temperature, high gross weight, and a short runway, the pilot failed to evaluate the conditions that existed in relation to the performance capability of the airplane.

Analysis

Primary failure mode
Fuel management
First missed decision gate
Pilot could have reduced load to within weight limits before takeoff.

NTSB coding

Evidence available

  • Photos
  • 17 docket documents
View NTSB final reportView NTSB docket

Docket documents17

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