Knowing Ice - Again

There are rules about flight into known or forecast icing conditions for Part 135 and 121 operators, but there is nothing in Volume 14 of the Code of Federal Regulations (commonly called the Federal Aviation Regulations) specifically prohibiting Part 91 flight into known icing. Instead, we look to 91.9(a). This prohibits us from operating an aircraft contrary to its published operating limitations. Add a dose of careless and reckless conduct from 91.13, and you have a better picture of the regulatory background.

Mark Kolber

Sunday, December 16, 2018 at 12:00 AM ET

Verified

Key Takeaways:

The FAA clarifies that "known icing conditions" for Part 91 pilots encompasses both reported and forecast data, emphasizing conditions that can produce ice rather than just observed ice, disavowing a controversial 2006 interpretation.
Historically, enforcement actions for icing violations are practical, targeting pilots who disregard clear warnings (forecasts, PIREPs), encounter substantial ice, and fail to implement an exit strategy or take appropriate action, often leading to an incident.
Pilots encountering inadvertent icing are advised to immediately implement an exit strategy, coordinate with ATC, and declare an emergency if necessary, as proactive steps significantly reduce both safety and enforcement risks.

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Back in 2006, CFI Robert Miller wrote to the New York FAA Regional Counsel to ask for clarification of the rules applicable to flight into known ice. The response was unfortunate: “flying through clouds at an altitude that is near or below freezing would constitute flight into known icing conditions.” Furthermore, the flight would be “a violation whether the aircraft accretes ice or not.” There you have it. Combine visible moisture and freezing temperatures with the large area covered by an AIRMET ZULU and we’d better stay on the ground in winter, or else! Clearly, this was a response that supported pilots’ worst fears about the FAA.

The result was loud and widespread criticism, with AOPA leading the charge. The FAA Chief Counsel not only disavowed the contents of the Miller Letter, but took the rare step of officially and publicly floating a proposed revision before signing off on it! The result was the 2009 Bell Letter. You can pick up a copy of the letter from the FAA Chief Counsel website. It is worth reading but, to summarize, it did nothing to change the rules or enforcement policy as it had existed for more than 40 years.