EASA SIB CE-09-40R1: Commander Models 111, 112 and 112A - Wing Flap Switch.

What to do

Operators and maintenance personnel should incorporate flap cycling and flap switch function checks into preflight inspections to verify proper operation. Any inoperative or incorrectly installed flap switches must be replaced before the next flight, with the Cutler Hammer P/N 8832K6 identified as the authorized replacement part. Additionally, operators should update their normal procedures to include visual verification of flap position and switch behavior during preflight and before engine start.

Summary

Special Airworthiness Information Bulletin SAIB CE-09-40R1 is an FAA informational bulletin addressing a potential airworthiness concern with the wing flap switch on CPAC, Inc. (formerly Commander Aircraft Company) Models 111, 112, and 112A airplanes. The bulletin highlights issues related to improper operation or installation of the flap switch, which can cause unintended full flap extension during critical phases of flight. It provides guidance to operators and maintenance personnel to ensure proper flap switch function and flap position verification.

What changed

SAIB CE-09-40R1 revises the original SAIB CE-09-40 by including references to the Model 111 aircraft, correcting the address for Commander Premier Aircraft CPAC, Inc., and adding information about an authorized replacement flap switch, the Cutler Hammer part number 8832K6. It also clarifies the flap switch operation and potential failure modes that could lead to continuous flap extension.

Why it matters

This bulletin is important for aviation professionals because improper flap switch operation or installation has been linked to multiple takeoff and go-around accidents involving Commander 112 aircraft. Ensuring correct flap switch function and verifying flap position can prevent inadvertent full flap extension, which is critical for safe aircraft handling during takeoff and other flight phases. Maintenance and operational procedures must address these risks to maintain flight safety.