What happened
On June 24, 1985, at approximately 0520 hours PDT, an agricultural aviation incident occurred near the Thomas Ranch Strip in California. A Cessna AG Truck 188B, identified by registration N9966J and operated by Ag-Flight, Inc., was preparing for a flight to apply sulfur on a local vineyard. The aircraft was registered to James L. Thomas.
The pilot reported that all normal preflight operations were conducted prior to the incident takeoff, with no abnormal indications noted during the inspection. However, during the takeoff roll, the aircraft exhibited slower-than-normal performance and sluggish acceleration. As the aircraft lifted off, it entered a near-stall condition before striking the brim of an irrigation canal. The impact caused the aircraft to tumble into a field beyond the canal.
The crash resulted in the total destruction of the aircraft due to impact forces and a fire ignited by the burning sulfur cargo carried within the plane. The certificated Airline Transport Pilot (ATP) sustained minor injuries, specifically to his eyes, from the burning sulfur. Visual meteorological conditions prevailed at the time of the accident, and no flight plan had been filed.
The investigation
The investigation focused on the performance characteristics of the aircraft during the takeoff phase and the condition of the cargo. Examination confirmed that the aircraft was carrying sulfur, which contributed to the post-crash fire. The pilot's account of sluggish acceleration and a near-stall at lift-off was consistent with the physical evidence of the impact location against the canal brim.
Findings
Contributing factors to this accident included:
- Sluggish acceleration during the takeoff roll
- Loss of control due to a near-stall condition at lift-off
- Impact with an irrigation canal brim
- Fire caused by burning sulfur cargo