Two pilots reported seeing a drone at 3,500 feet near Teterboro Airport in New Jersey on Jan. 22, prompting a ground stop at nearby Newark Liberty International Airport. The disruption, weeks after reported drone sightings led to chaos at a British airport, highlighted the lack of established procedures to respond to a real or perceived drone threat to air safety.
The federal government shutdown began about the time that reported drone sightings around Gatwick Airport disrupted the holiday travel plans of about 140,000 passengers and brought Britain’s second busiest airport to a standstill for around 36 hours.
DJI issued a statement Jan. 11 responding to the reported drone sightings around Gatwick and other airports, urging caution and noting that in many cases drone sighting reports ultimately were found to be cases of mistaken identification.
Collected and summarized from the source below by Minh Pham https://www.aopa.org/news-and-media/all-news/2019/january/23/flights-disrupted-after-drone-reports