Updated January 16, 2023: Click here to read the same service letter related to other models including the 180 and 182.

Textron Aviation has released Service Information Notifications for certain 300 and 400 Cessna models. For affected aircraft, the original landing gear warning horn and stall warning horn are no longer available. If either needs to be replaced, new ones are available and will require an additional bracket for installation. The service documents provide instructions to remove the original landing gear warning horn and stall warning horns. At the customer’s discretion, they may choose to replace only the landing gear warning horn, or the landing gear warning horn and the stall warning horn together.

Affected models for both the landing gear warning horn and the stall warning horn are the 310Q, T310Q, 310R, T310R, 335, 340, 340A, 401A, 401B, 402A, 402B, 402C, 404, 414, 414A, 421A, 421B, 421C 425, and 441.

Landing Gear Warning Horn

Models 425 and 441 Click Here (then look for your serial number)

Models 310Q/T310Q and 310R/T310R Click Here (then look for your serial number)

Models 335, 340, 340A Click Here (then look for your serial number)

Models 401, 402, 404, 414, 421 Click Here (then look for your serial number)

Stall Warning Horn

Models 425 and 441 Click Here (then look for your serial number)

Models 310Q/T310Q and 310R/T310R Click Here (then look for your serial number)

Models 335, 340, 340A Click Here (then look for your serial number)

Models 401, 402, 404, 414, 421 Click Here (then look for your serial number)