An unclearly worded Notam and a verbal discussion that led to incorrect assumptions caused a chartered Raytheon (Beechcraft) King Air B200 to land on a runway where ground personnel were preparing to launch gliders, according to a final report by the Australian Transport Safety Bureau (ATSB). No one was injured in the Dec. 18, 2016 incident on Runway 17 at Horsham Airport, Victoria, but the ATSB said, “This incident highlights the critical importance of what you say and how you say it for both the written and spoken word.”
The Notam on glider operations never said explicitly that Runway 17 would be closed. Instead, it said that the runway could be used outside of the hours between noon and 2 p.m. but only by obtaining “prior arrangement with the [glider] competition director.”
At the time of the incident, about 10:30 a.m., ground personnel were preparing to lay down glider launching ropes on Runway 17. The King Air pilot, who was aware of the Notam, determined wind conditions favored Runway 17 (rather than 08) and gave an inbound broadcast on the local Unicom frequency. When the ground personnel saw the King Air prepared to land on Runway 17, they moved out of the way.
Two days before the incident, the King Air pilot and the glider event director discussed the flight. But based on their respective understandings of the Notam’s wording and the conversation they had, the King Air pilot assumed Runway 17 was available before noon, while the director and ground personnel assumed the runway was closed all day.