UA6070 IAD-MSP tonight delayed 13.5 hours...

Was showing ontime (5:45pm) until about 90 minutes before departure, at which point it posted 2h45m delayed due to inbound crew who were apparently on another aircraft that went MX so couldn't get to IAD.

Then at around 6:15pm it looks like they did an aircraft switch to give our good aircraft (which had been on the ground since 4pm) to another flight, and gave us a broken one as the reason for the delay is now "... maintenance team must wait on the arrival of a part to service your plane's navigation system".

New estimated departure is 7:10am tomorrow.

Update: Departure moved to 10am, then 11am, then Canceled with most people rebooked on the Delta direct flight at 12:30pm...