When is 17347 used?

• A. When main body weather is good but RMKs section at destination and alternate is down to half of the required weather
• B. When the RMKs section is unavailable
• C. When the destination weather exceeds minimums
• D. When the airspace is congested

Answer: (A)

17347 is used when you can rely on the main body weather, but the RMK remarks about weather at both the destination and the alternate are degraded to only half of what is required. In that situation, you’re not fully dependent on the RMK data, so you apply this rule to proceed with the flight plan while still meeting the safety margins defined by the available weather information. If the RMK section were simply unavailable, or if the destination weather already clearly exceeds minimums with complete data, this condition wouldn’t apply. And if the issue were unrelated to weather data, such as airspace congestion, 17347 wouldn’t be the rule you’d use.