"The Pope is coming, the Pope is coming"!

As a young boy back in 1965 I went with my farther to see the Pope land in New York City.
We were lucky to work our way close to the fence see the plane land.
Right on time a plane started to descend and I started jumping up and down shouting "The Pope is coming, the Pope is coming"!
My farther looked carefully at the plane and shook his head. "The Pope's not on that plane." he said.
The plane landed, and the Pope wasn't on it.
A little while later I saw another plane coming in for a landing. I started jumping up and down shouting "The Pope's coming, the Pope's coming"!
My farther looked carefully at that plane too, and shook his head. "The Pope's not on that plane." he said.
The plane landed, and The Pope wasn't on it.
A little more time passed before I saw another plane coming in for a landing. I turned to my farther, who seemed to know EVERYTHING, and asked him "Is the Pope on that plane"?
He carefully studied the plane and nodded his head, "Yes, the Pope is on that plane".
My farther is so smart! The plane landed, and the Pope got off.
Later I asked my farther how he knew that the Pope had been on that particular airplane.
He told me that the first plane that landed was an Eastern Air Lines flight, and he didn't think that the Pope would be on that one.
The second one was a Northeast Airlines flight, and he didn't think that the Pope would fly that airlines either.
"But the last plane just had to have the Pope on it." he said.
"I knew it as soon as I saw what they had painted on the tail of the plane", he said.

Can anyone figure out the answer?
We were lucky to work our way close to the fence see the plane land.
Right on time a plane started to descend and I started jumping up and down shouting "The Pope is coming, the Pope is coming"!
My farther looked carefully at the plane and shook his head. "The Pope's not on that plane." he said.
The plane landed, and the Pope wasn't on it.
A little while later I saw another plane coming in for a landing. I started jumping up and down shouting "The Pope's coming, the Pope's coming"!
My farther looked carefully at that plane too, and shook his head. "The Pope's not on that plane." he said.
The plane landed, and The Pope wasn't on it.
A little more time passed before I saw another plane coming in for a landing. I turned to my farther, who seemed to know EVERYTHING, and asked him "Is the Pope on that plane"?
He carefully studied the plane and nodded his head, "Yes, the Pope is on that plane".
My farther is so smart! The plane landed, and the Pope got off.
Later I asked my farther how he knew that the Pope had been on that particular airplane.
He told me that the first plane that landed was an Eastern Air Lines flight, and he didn't think that the Pope would be on that one.
The second one was a Northeast Airlines flight, and he didn't think that the Pope would fly that airlines either.
"But the last plane just had to have the Pope on it." he said.
"I knew it as soon as I saw what they had painted on the tail of the plane", he said.

Can anyone figure out the answer?