EASA SIB 2024-08: Misidentification and Erroneous Selection of Propeller Feathering Controls in Flight

What to do

Operators of large turboprop aeroplanes should train flight crews to recognize and report errors involving propeller feathering controls under mandatory occurrence reporting schemes. Type certificate holders and supplemental type certificate holders should review and verify that cockpit alert systems adequately signal such errors and ensure this information is included in aircraft documentation. No specific compliance deadlines are stated, as the bulletin provides non-mandatory recommendations.

Summary

EASA Safety Information Bulletin 2024-08 is issued to raise awareness about the risk of misidentification and erroneous selection of propeller feathering controls in flight on large CS-25 turboprop aeroplanes. The bulletin references an accident involving an ATR72/212A version 500 near Pokhara International Airport, where inadvertent feathering of both propellers led to total thrust loss and a fatal crash. It highlights the importance of flight crew alerts and cockpit indications in detecting such errors promptly to prevent loss of control.

What changed

EASA SIB 2024-08 introduces guidance to operators, type certificate holders, and supplemental type certificate holders on recognizing and managing the safety risks related to erroneous propeller feathering control selection. It emphasizes the need to assess cockpit alert systems and ensure flight crews are aware of error reporting procedures. This bulletin does not mandate any airworthiness or operational directives but provides recommendations to improve safety awareness and reporting.

Why it matters

This bulletin matters because erroneous feathering control selection can cause total thrust loss and catastrophic accidents, as demonstrated by the referenced ATR72 accident. Aviation professionals, including operators and maintenance organizations, need to understand the human factors involved and ensure that cockpit alerts and procedures effectively support error detection and recovery. Compliance teams should also be aware of reporting obligations to enhance safety data collection and prevention strategies.