Preliminary Identification and Analysis of Encoding Errors in GA Pilot Weather Reports (PIREPs).

Pilot Weather Reports (PIREPs) are one way that pilots may provide actual weather conditions to other pilots, air traffic control (ATC), flight service, and the national weather service. These pilot reports provide firsthand real-time information about the weather conditions that pilots encounter. PIREPs communicate weather information that is difficult to obtain otherwise such as icing aloft, turbulence, sky cover, and low-level wind shear. This firsthand information provided through PIREPs is critical to aviation safety and weather forecasting. For General Aviation (GA) pilots, PIREPs are of special importance because they may not have on-board weather radar or access to a dispatch service that is commonly used by the airlines. Additionally, many of these pilots may be operating smaller and lighter aircraft compared to those operated by the airlines. For an immediate radio PIREP to occur, the pertinent weather condition encountered is: 1) recognized by the pilot, 2) communicated via radio, 3) written by receivers, 4) encoded into PIREP codes, and 5) disseminated. There are potential errors that may result in PIREPs that are untimely, misleading, erroneous, or never get disseminated. Assuming that the weather information submitted by the pilot was complete and error-free, this study aims to identify the types of coding errors, frequency by PIREP text element indicators (TEIs. e.g.,/SK,/TP,/IC), and their proportions. Statistical and graphical analyses were used. In this study, PIREPs obtained from the Iowa State University Iowa Environmental Mesonet (IEM) PIREPs database are analyzed. A spring/summer time frame is desirable to capture a variety of GA PIREPs. The 06/01/2019 to 07/31/2019 timeframe was selected for the study, and aircraft types were limited. A total of 3,654 PIREPs were obtained from Cessna 172, Mooney Acclaim, and Piper Cub aircraft over this time frame. From this pool, 50 PIREPs from each of these three aircraft types were randomly selected and analyzed. The encoded PIREPs were compared to the encoding guidelines found in federal documents such as FAA Order JO 7110. U, Aeronautical Information Manual (AIM), Federal Meteorological Handbook No. 12, and the PIREP Form FAA Form 7110-2. From this study, a better understanding of PIREP coding errors may lead to the development of training to address submission and disseminating errors, and also provide requirements for automated systems. Better coding of PIREPs could lead to more PIREPS getting disseminated, and more informed and consistent analysis for weather forecasting. More accurate PIREPs have the potential to improve aviation safety. [ABSTRACT FROM AUTHOR]