CESSNA 310F — Performance Data

This service bulletin, issued by Kelly Aerospace, provides critical information regarding the upgrades and improvements available for JANITROL B-Series heaters used in various aircraft, including the Piper PA-31T Cheyenne. It emphasizes the importance of upgrading to the latest heater models during the next major overhaul to enhance performance and reliability. The bulletin outlines specific heater models, their changes, and the recommended practices for ensuring airworthiness and reducing field problems associated with older heater technology. The document is FAA approved and aims to assist aircraft owners and maintenance personnel in making informed decisions about heater upgrades.

• Upgrade to the latest heater model during the next major overhaul to improve performance.
• The original heater model for the PA-31T Cheyenne is the 62D33, succeeded by the 10E21-4EL model.
• Periodic inspections of the combustion tube are required per FAA AD-NOTE #96-20-07.
• Heaters failing pressure decay tests must undergo major overhauls, including combustion tube replacement.
• Installation authority is determined by the airframe manufacturer, and installers should refer to current publications.