"First we did a freefall, probably 200-to-300 feet. Everything was shaking, the whole cabin was shaking and everything!" said a passenger.
"The side wall of the plane looked just like it was going to come right off the plane! It was very scary!" said another passenger.
On September 16, 2004, an American Airlines MD-80 hit a large bird just after take-off from O'Hare Airport. The culprit-- a cormorant. It's a large bird that got sucked through the jetliner's left engine.
"I have honestly been amazed at how some of our feathered friends seem to know exactly where we are," said Captain Kru Krueger, United Airlines.
United Airlines Captain Kru Krueger and his first officer Bob Chapman have both been in the cockpit when their 87 ton aircraft encountered a flock of birds.
"One hit the windscreen right in front of my face. My natural reaction was to duck and I'm the pilot flying! I said, 'I'm down!' The captain took the airplane and we continued the take-off. It was very close, very critical phase of flight, we had to continue. To abort would have been a much more dramatic event, more dangerous," said Bob Chapman, United Airlines pilot.
Large birds are a growing nuisance at America's airports. In 1990, there were just 1700 reported bird strikes. Last year, that number more than tripled to 5700 bird strikes.
While some do little damage, any bird over four pounds can choke an engine, spark a fire and force an emergency landing. It's a scenario pilots at United and other airlines train for time and time again.
"You are clear for take-off, left turn heading zero one zero," said Air Traffic Control.
At United's training facility in Denver... we hitched a ride aboard one of the airline's full-motion simulators. Here, pilots can experience dangers in the sky from the safety of the ground.
Reporter: "You see the bird out the window."
Pilot: "It looks like that was a whole flock of birds -- it looks like we've ingested one into the number one engine as the EET goes back up."
A split second after one engine goes down... cockpit computers immediately route more thrust to the remaining engine.
"United 320, we've lost an engine, we'll be declaring an emergency going straight and out," said pilot.
Even one engine has enough power to get a plane into the air but pilots have to act fast. They have a split second to decide whether to stop the plane before you run out of runway or whether they have to get in the air.
"Absolutely," said pilot.
Experts say damage from bird and other wildlife strikes cost the airline industry half-a-billion dollars a year. They also put passengers at risk. The smoke you see at the center of the screen is what's left of a military jet that crashed in Alaska in 1995. Twenty-four people died after the plane hit a flock of Canadian Geese.
It's why some airports are going to great lengths to discourage birds from gathering on airport grounds.
"Areas around airports have all been developed. They're not out in the country anymore so the airport is the largest piece of green space available for birds to go to," said Richard Dolbeer, USDA Wildlife-Airport Expert.
In Fort Myers, bird strikes dropped by 75-percent after this border collie named "Jet" began patrolling the grounds. In Dallas and Chicago, officials are looking at something called "Bird-ar."
"What they've been able to demonstrate is having that radar might prevent birds from accumulating in a certain area and it will actually discourage them from gathering and move them out of the area," said Commissioner John Roberson, Chicago Department of Aviation.
Until then... big bangs, screaming starter pistols and good grounds keeping are being used to keep birds away from these man-made flying machines.
"In most cases I'm not too worried about the airplane because the bird will definitely get the short end of the stick," said Captain Krueger.