What happened
On the afternoon of May 5, 1998, a Cessna A188B agricultural aircraft, registration CS-AQU, was performing rice sowing operations near Alcáçovas, in the Alcácer do Sal region. The aircraft was being operated by Aeropiloto using a seasonal agricultural strip known as Barrosinha, which had a usable length of approximately 400 meters.
During a takeoff attempt at approximately 17:30 local time, the aircraft was carrying roughly 400 kilograms of rice seed in its hopper. As the aircraft reached the end of the takeoff roll, it failed to maintain its climb path and began to lose altitude. The aircraft descended into a rice cultivation tank, where the impact with the water caused it to stop abruptly and nose-over. The aircraft sustained severe damage to the canopy, rudder, wingtips, engine cowling, and propeller. An accidental spill of Avgas and oil contaminated the water in the paddy.
The investigation
The GPIAAF investigation examined the operational conditions of the flight, the aircraft's weight, and the environmental factors at the time of the accident. Investigators reviewed the pilot's actions, the aircraft's maintenance records, and the characteristics of the agricultural airstrip. The investigation also looked into the loading procedures used for the agricultural mission, noting that the hopper load was intentionally reduced to 400kg due to the short runway length.
Findings
- The aircraft was operating at the extreme edges of its operational envelope due to the short runway length and the lack of significant headwind.
- The pilot reported a possible momentary tailwind component at the end of the takeoff roll, which contributed to the loss of lift.
- There was a possibility that the aircraft was overweight at takeoff, as the pilot's attention may have been diverted during the loading process.
- The pilot was uninjured and able to exit the aircraft on his own.
Safety action
- Pilots performing agricultural work should maintain strict oversight during the hopper loading process, utilizing a written log to track quantities and ensure weight and balance calculations are strictly followed.
- Pilots operating at the limits of the aircraft's safety envelope—considering runway length, maximum load, wind, and temperature—must strictly adhere to the procedures outlined in the aircraft's Approved Flight Manual.