DENVER -- It isn't often that a person rides on an airplane that loses one of its engines.

And it's not frequent for a person to see flames shooting from the wings of the plane.

But what was most peculiar to Denver' Shannon McCarthy was how calm all of the passengers were after the Frontier Airlines flight they were riding on damaged its engines after hitting a flock of geese on Saturday evening.

Frontier Airlines flight 820 left Kansas City and was due to arrive at Denver International Airport at 7:30 p.m. on Saturday night. But shortly after takeoff, the plane hit a number of birds, said Frontier Airlines spokesman Steve Snyder.

McCarthy was sitting in an aisle seat right behind the engines, so he had a clear view of the damage.

"It was a standard takeoff and about halfway into the ascent there was four booms," McCarthy said. "And the first one was just massive. After each one there was flames shooting up from under the wing. So we knew we hit something"

Snyder said the plane turned around and landed back at Kansas City International Airport without incident.

"The pilot completely kept control he never lost control," McCarthy said. "He just turned us around and put us on the tarmac and put us right back to the gate."

The Federal Aviation Authority is investigating the incident. A spokesman said that the airplane, an Airbus 319, hit the flock at 4,000 feet. The most damage was caused to the No. 2 engine, although the No. 1 engine also was struck.

Frontier Airlines put all of the passengers up in hotel rooms overnight and got them to their destinations on Sunday, Snyder said.

McCarthy said even though it wasn't Frontier's fault, the airline gave every passenger a free flight voucher and went out of its way to make them comfortable.