Story highlights Flight 4650 on March 22 was a 50-seat jet, according to Flightaware

FAA: The unmanned aircraft looked like a miniature F-4 Phantom jet, pilot said

FAA: A jetliner's pilot reported a near collision with a drone over Florida

Drones getting sucked into jet engines could be "catastrophic," he adds

A Federal Aviation Administration official warned this week about the dangers of even small unmanned aircraft, pointing specifically to a recent close call involving a drone and a commercial airliner that could have had "catastrophic" results.

Jim Williams, the head of the FAA's Unmanned Aircraft Systems (UAS) office, discussed various potential perils during a presentation Thursday to those attending the Small Unmanned Systems Business Expo. A video of his talk in San Francisco, and those of others, to those who operate, create or otherwise are involved or interested in such unmanned aircraft was posted to YouTube

After saying "the FAA has got to be responsive to the entire industry," Williams referred to a pair of incidents in which drones caused injuries to people on the ground. One came at an event at Virginia Motor Speedway in which an "unauthorized, unmanned aircraft" crashed into the stands, and in the other a female triathlete in Australia had to get stitches after being struck by a small drone.

Then, Williams segued to a pilot's recent report of "a near midair collision" with a drone near the airport in Tallahassee, Florida. The pilot said that it appeared to be small, camouflaged, "remotely piloted" and about 2,300 feet up in the air at the time of the incident.

"The pilot said that the UAS was so close to his jet that he was sure he had collided with it," Williams said. "Thankfully, inspection to the airliner after landing found no damage. But this may not always be the case."

Photos: Photos: A gathering of drones – Drone hobbyists watch a pair of the aircraft take to the air at a recent Make Drone "Fly-In" event in American Canyon, California. Click through for more scenes of drones and their human masters. Hide Caption 1 of 9 Photos: First-person piloting – 3D Robotics employee Pablo Lema views live video streamed from the drone above his head. The first-person view is displayed on his goggles, while he steers the device with a hand-held controller. Hide Caption 2 of 9 Photos: Built for photography – Chris Anderson, founder of 3D Robotics, holds the company's new Iris drone . The device is designed for aerial photography and will cost $750 when it is released in February. Hide Caption 3 of 9 Photos: Pair a drone with an iPad – Fighting Walrus co-founder Andy Brown demonstrates his company's iPad accessory (mounted on the left side of the tablet), a $129 device for controlling and communicating with drones. Hide Caption 4 of 9 Photos: Experienced pilot for hire – Zolie Sarriugarte, 7, gets ready to take a drone for a spin. Sarriugarte likes drones because "if there's a ball stuck up in a tree you can go fly over and knock the ball out." Hide Caption 5 of 9 Photos: Cockpit on an iPhone – Live video from a DJI Phantom drone is displayed on an iPhone app. The Phantom controller has a special mount for the smartphone. Hide Caption 6 of 9 Photos: Heavy-duty drone – A young drone fan checks out the Game of Drones damage-resistant flying vehicle, which can withstand paintball hits, shotgun blasts and baseball bats. Hide Caption 7 of 9 Photos: Instant aerial antenna – Inventor Glenn Elmore says drones can be used to launch his inexpensive antennas high in the air where they can get better signal strength. The technology could be useful after natural disasters to quickly create temporary communication networks. Hide Caption 8 of 9 Photos: Drone, camera, action! – An enthusiast takes a drone, outfitted with a camera, for a spin in the test flight area. Aerial photography is one of the most popular uses for smaller consumer drones. Hide Caption 9 of 9

Photos: SkyCall: The drone that's your personal tour guide Photos: SkyCall: The drone that's your personal tour guide Lost? SkyCall to the rescue – Meet SkyCall, a flying robot that guides you to your destination. Find out how it works... Hide Caption 1 of 6 Photos: SkyCall: The drone that's your personal tour guide Step 1: Call – After downloading the SkyCall app to your smartphone, contact the drone, which has been designed by scientists at the Massachusetts Institute of Technology. Hide Caption 2 of 6 Photos: SkyCall: The drone that's your personal tour guide Step 2: GPS navigation – The flying robot uses your phone's GPS location to find you. It also features it's own in-built GPS to find destinations. Hide Caption 3 of 6 Photos: SkyCall: The drone that's your personal tour guide Step 3: Walk and talk – Type in your room number, and SkyCall will guide you there, pointing out landmarks along the way via a small speaker. Featuring four propellers, the quadrocopter flies at 6 kilometers per hour and will wait for you, should you fall behind. Hide Caption 4 of 6 Photos: SkyCall: The drone that's your personal tour guide Step 4: Futuristic footage – Featuring a small in-built camera, it is hoped that one day SkyCall could be used for everything from a tourist guide to a search-and-rescue robot. The footage could be relayed to rescue teams, or link up to your phone to provide a bird's eye view of the journey. Hide Caption 5 of 6 Photos: SkyCall: The drone that's your personal tour guide Step 5: Safe and sound – SkyCall delivers you straight to the door. The high-tech robot is the brainchild of researchers at MIT's Senseable City Lab, who are developing ways drones could be used in everyday life. Hide Caption 6 of 6

According to the FAA, the incident took place on March 22 and involved as U.S. Airways Flight 4650 going from Charlotte, North Carolina, to Tallahassee.

The pilot claimed to pass "an unreported and apparently remotely controlled aircraft ... five miles northeast of the Tallahassee airport, according to the federal agency.

Such close calls are rare, the FAA notes.

The pilot reported that the small unmanned aircraft involved looked similar to an F-4 Phantom jet, and not like a helicopter that might hold a camera that many associate more closely with drones. Such planes have gas turbine engines and can fly higher than an average drone, according to the FAA. Neither the drone in this case, nor its pilot, have been identified.

In its own statement, US Airways said that it was aware of this reported "incident with one of our express flights, and we are investigating."

Explaining why this event is significant, Williams referenced to the so-called "Miracle on the Hudson" from 2009, when US Airways Flight 1549 safely crash-landed in New York's Hudson River after striking at least one bird upon takeoff from LaGuardia Airport.

Such bird strikes are dangerous enough; a drone, even a small one, getting sucked into a jetliner's engine could be even worse, Williams said.

"Imagine a metal and plastic object -- especially with (a) big lithium battery -- going into a high-speed engine," he added. "The results could be catastrophic."

All these incidents speak to "why it is incredibly important for detect-and-avoid standards (for small unmanned aircraft) to be developed and right-of-way rules to be obeyed," Williams said. He added that such standards are in the works.

His agency reiterated this sentiment in its statement Friday.

"The FAA has the exclusive authority to regulate the airspace from the ground up, and a mandate to protect the safety of the American people in the air and on the ground," the agency said. "...Our challenge is to integrate unmanned aircraft into the busiest, most complex airspace in the world. Introduction of unmanned aircraft into America's airspace must take place incrementally and with the interest of safety first."

As to current regulations, Williams noted the FAA has appealed a federal judge's decision in a case involving businessman Raphael Pirker.

Pirker used a remotely operated, 56-inch foam glider to take aerial video for an advertisement for the University of Virginia Medical Center. The FAA then fined him $10,000 for operating the aircraft in a "careless and reckless manner."

A judge on March 6 agreed with Pirker that the FAA overreached by applying regulations for aircraft to model aircraft, and said no FAA rule prohibited Pirker's radio-controlled flight.

But on Thursday, Williams said that another judge had stayed this ruling pending the FAA's appeal.

"Nothing has changed from a legal standpoint," he said, "and the FAA continues to enforce the airspace rules."