Federal investigators released a preliminary report on an incident involving President Donald Trump's helicopter. A meeting was held with air traffic controllers to discuss communication issues prior to the incident. The controllers had reported problems receiving warnings about upcoming flights.

An alternative plan was agreed upon but proved unsuccessful. This plan involved relaying important radio calls through another party. The incident in question occurred when a jet took off as the president's helicopter was departing.

Further details about the incident and the investigation are available from the National Transportation Safety Board's report. The board's findings show a potential violation of safety procedures.