Spotted from inside Romney's plane: Biden's plane. (Felicia Sonmez via Instagram)

CLEVELAND, Ohio -- Republican presidential nominee Mitt Romney landed here Tuesday morning and waited in his campaign plane for his running mate, Paul Ryan, to touch down from Wisconsin, for a joint Election Day stop.

But 22 minutes after Romney arrived, another plane unexpectedly landed across the tarmac.

It was Air Force Two.

For the third time in as many days, Romney and Vice President Biden's planes have crossed each other on the same tarmac. On Sunday, it was a chance meeting on the same Cleveland runway. On Monday, it was at Dulles Airport just outside Washington.

And on Tuesday, it was back in Cleveland, where Biden was making an unannounced Election Day stop -- the same day and at the same time that Romney and Ryan were to hold an event of their own here.

Romney senior adviser Stuart Stevens made his way to the back of the plane as the motorcade was passing outside.

"I thought they said that it was panic that we were campaigning today," he mused to the handful of reporters on the aircraft. "How about that?"

As Biden's motorcade sped away from Air Force Two, Romney was sitting in his seat at the front of his own plane. It was unclear whether the governor -- who has been working Tuesday on his Election Night speech -- knew that his fellow White House challenger was across the tarmac, visible just outside his window on the right-hand side of the plane.

A few minutes later, vice presidential candidate Paul Ryan's plane rolled up next to Romney's. The Wisconsin congressman, clad in a dark suit, briskly made his way over to and boarded Romney's plane.

After a few minutes, the two Republican candidates deboarded together, Romney holding a small duffel bag. Ryan waved to reporters as the two made their way down the steps, then they entered an SUV and sped off.