Incident During Approach at ARN Involving an Embraer 175

Incident Overview and Investigation Details On 5 February 2015, an incident occurred during an approach to land at ARN involving an Embraer 175 operated by PLL LOT. The investigation was supervised by Maciej Lasek and concluded on 7 December 2015. The event was classified as an incident, and no fatalities or injuries were reported among the 37 persons on board. ## Sequence of Events During the approach, the flaps were moved to position “1” at a speed of 260 knots. The system generated a warning for excessive speed, prompting the pilot flying (PF) to return the flap lever to position “0”. The captain believed that the brief movement to position 1 and immediate retraction would not cause the flaps and slats to extend. Consequently, the situation was not reported to the Maintenance Control Center (MCC) by telephone at the time. After landing in WAW, the technical services were informed of the event. ## Technical Analysis and Maintenance Actions Initial data from the recorders on the parking stand did not confirm a speed exceedance due to an error in the rule. Technical personnel performed the first phase of the post-speed-exceedance inspection on the flaps. At the request of the MCC engineer, an inspector from the Aviation Safety Department conducted a detailed flight analysis, which revealed an exceedance of the allowable speed by 36.5 knots. After correcting the rule error and repeating the analysis, the operations engineer decided to perform the second stage of the post-speed-exceedance inspection on the flaps (AMM 05-50-07) for the slats only. ## Causes and Preventive Measures The incident was caused by setting the flaps to position “1” at an excessive flight speed. This resulted from the pilot flying issuing the “Flaps” call without checking the flight speed, and the pilot monitoring (PM) moving the flap lever without verifying the speed. Preventive measures included reviewing the accuracy of alarm rules, informing the fleet instructor chief of the actions taken, describing the incident in the monthly Fleet Bulletin, and discussing the event during periodic pilot training. Special emphasis was placed on the fact that even a brief movement of the flap lever to position “1” initiates the slat extension process. The commission did not issue safety recommendations.