CESSNA F-172 H — Service Bulletins

This document is an Airworthiness Directive (AD) issued by the FAA concerning Cessna Model 172 airplanes that have been modified under Supplemental Type Certificate (STC) SA01303WI. The AD mandates specific modifications to the engine electrical system, including the installation of a full authority digital engine control (FADEC) backup battery and the replacement of the FADEC backup battery every 12 months. This directive was prompted by an incident involving an in-flight engine shutdown due to a loss of electrical power, highlighting the importance of maintaining electrical integrity for safe operation. The document outlines compliance requirements, estimated costs, and procedures for the modifications and battery replacements necessary to ensure continued airworthiness of the affected aircraft models.

• Install a FADEC backup battery within 100 hours or 30 days after May 26, 2011.
• Replace the FADEC backup battery every 12 calendar months.
• Estimated cost for compliance is $2,860 for 14-volt systems and $3,200 for 28-volt systems.
• The AD applies to Cessna Model 172 airplanes modified by STC SA01303WI.
• Failure to comply may result in uncommanded engine shutdown.