What is a common method for pilots to determine the proper runway at an airport without a control tower?

The method of contacting UNICOM to ask for an advisory is a practical approach for pilots when determining the proper runway at an airport without a control tower. UNICOM frequencies are typically used for non-towered airports and allow pilots to communicate with each other, as well as obtain information regarding runway conditions, active flight operations, and traffic patterns. This dialog can provide valuable insights from other pilots who might have recently landed, taken off, or are currently in the traffic pattern, thus assisting in making informed decisions about which runway to use.

Additionally, while listening to ATIS might provide some information at airports with such services, it is not applicable at non-towered fields where ATIS does not exist. Relying solely on GPS is also not advisable, as it does not provide real-time traffic information or details about other aircraft or runway conditions. Observing other aircraft is useful but can be insufficient without active communication to determine the best option on that particular day. Therefore, using UNICOM for advice combines various elements of safety and situational awareness, making it the most effective method in this scenario.