On 27 May 2015, a Boeing 717‑200 aircraft, registered VN‑NXM, was being operated on a flight from Brisbane to Gladstone, Queensland. The captain was the pilot flying (PF) and the first officer was the pilot monitoring (PM). Conditions were fine and clear.

The take‑off roll was normal in all respects, but soon after take-off, the stickshaker activated. The PF lowered the aircraft pitch attitude and the stickshaker stopped. Moments later, the PM noticed that the flap/slat control handle was set to the UP/RET (flaps up/slats retract) position. The PM called ‘flaps’ and moved the handle to the previously determined take‑off setting position.

As the aircraft climbed through about 700 ft, the crew raised the landing gear, and later during the climb, the flaps were selected up and the slats were retracted. The flight continued to Gladstone without further incident.

A review of the flight data showed that the aircraft had been appropriately configured for take‑off. Soon after take-off, at around the time the landing gear handle would normally be selected to the UP position, the flap/slat control handle was moved to the UP/RET position. Movement of the flap/slat control handle was shortly followed by stickshaker activation. Moments later, the flap/slat control handle was moved back to the take-off configuration setting previously determined by the crew.

Available evidence suggests that the PM inadvertently selected the flap/slat handle to the UP/RET position soon after take-off, instead of selecting the landing gear handle to the UP position. While the reasons are unclear, the most likely explanation resides in an understanding of human error types, particularly slips and lapses – referred to collectively as execution errors.

This incident highlights the susceptibility of pilots to execution errors such as slips and lapses, irrespective of knowledge and experience. Pilots are encouraged to reflect on the circumstances surrounding this incident to help build their own awareness of human factors issues associated with operating complex equipment in a highly dynamic environment.

Aviation Short Investigations Bulletin - Issue 45

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