For nearly an hour, the aircraft, identified as IRON99, circled the city in an oval shaped pattern before heading to Oklahoma.
Thousands of people concerned about the strange sighting called local news station Denver 7 to report what they were seeing. The station reached out to the Denver Airport, local military bases, and government agencies, but was able to learn nothing.
“Further research into the plane's title of IRON99 turned up bases in the northeastern part of the nation that frequently give out the title of IRON to their military flights, however the title is usually reserved for T-38 aircraft, which are distinctly black,” the station reported, noting that this plane was white.
On Thursday, the Navy responded to the station confirming that the plane was in a holding pattern over Denver the day before, but stated that the mission is classified.
Lieutenant Leslie Hubbell, the assistant public affairs officer for Commander Naval Air Forces detailed that the IRON99 is a Navy E-6B Mercury jet aircraft, created by Boeing at a cost of $141.7 million per unit, Denver 7 reported.
"The overall mission of the E-6B is command, control and communications abilities to direct and employ strategic resources," Hubbell said.
The aircraft was flying a holding pattern over Denver, at the instruction of the Federal Aviation Administration en route to Tinker Air Force Base, where it is stored.
Though they were unable to get an on-the-record statement from the US Navy about the mission, a source reportedly told the station that the aircraft was on a Department of Defense training mission, focused on electronic surveillance.
