Before some cutting-edge online retailer can use a drone to drop granola bars on your doorstep, a railroad born when Abe Lincoln was in Congress will first have to iron out the kinks.

BNSF Railway Co. is flying drones as far as 150 miles (240 kilometers) along the New Mexico desert to inspect tracks, helping the Federal Aviation Administration develop rules for operating unmanned aircraft beyond the pilot’s line of sight. That’s an essential step for expanding use to such commercial endeavors as deliveries by Inc. and other companies.

“We had to invent a lot of what we’re doing from scratch,” said  Todd Graetz, head of the drone team at Fort Worth, Texas-based BNSF, which traces its roots back to the Aurora Branch Railroad’s founding in 1849 and is currently controlled by billionaire  Warren Buffett. “It sets the stage for a number of other users.”

The “Holy Grail” is flying drones beyond what ground-based operators can see, said John Walker, co-founder of the Padina Group Inc. aerospace consulting firm. The potential uses -- from track inspections, to spotting criminals on the lam, to organ deliveries for hospitals -- will rival what happened a century ago, when airplanes became indispensable tools instead of stunt machines at county fairs, he said.

“It’s been barnstorming,” said Walker, a former FAA program director. “Now we’re getting into what is the commercial market.”

Missed Deadline

The FAA is eager to expand rules for long-distance drone flights, said Earl Lawrence, the agency’s director of the office of Unmanned Aircraft Systems Integration. The agency missed a congressional mandate to allow full integration of drones into U.S. airspace by last year, citing safety concerns.

Until recently, the FAA had allowed commercial drone flights only under a cumbersome, case-by-case application process. On Monday, the agency began permitting daytime flights within line of sight, no higher than 400 feet (120 meters), no faster than 100 miles per hour (160 kilometers per hour) and, generally, not above people. Those interim rules set a framework eventually to allow night flights, operations over populated areas and service beyond line of sight. The agency expects to introduce those rules next year, Lawrence said.

“How do you eat the elephant? One bite at a time,” he said. “We’re taking it in bites. We’re going from the less complex to the more complex.”

For more coverage of FAA rules on drone safety, click here.