LAS VEGAS — Amazon said Wednesday it could start making drone deliveries to consumers’ homes in just months, the latest in a string of big promises by the online retail giant that have yet to materialize in its long-promised futuristic network of package-delivering fliers.

Jeff Wilke, chief executive of Amazon worldwide consumer division, demonstrated the latest iteration of the package-toting aircraft that the firm promises will be fully autonomous at the company’s Re:Mars conference. The drone, Wilke said, would be able to make deliveries of up to five pounds at a range of 15 miles.

Wilke said the aircraft is also quieter than in earlier versions so that neighbors would be less bothered by deliveries. “Just because you want a package delivered quickly doesn’t mean you want you or your neighbors to hear it coming,” he said.

Companies including Amazon have long been working toward a future in which humans and trucks aren’t needed to deliver the millions of online orders consumers place each day. Google, UPS, DHL and Uber have experimented with the technology, which is envisioned to one day create a high-speed, air-delivery network for medical supplies, meals, spare parts and other smaller items.

Drones are designed to fly to a customer’s home without a human pilot and to detect obstacles such as wires, humans and dogs as it maneuvers to and from its destination. Many current drones rely on pilots who navigate them from control centers on the ground where they can monitor the flight path through cameras.

Delivery drones promise eliminating the cost of human involvement for smaller orders. But projects from Amazon, Google and others have stalled in large part because of U.S. regulatory challenges.

Amazon hasn’t settled on where it would start the drone deliveries, Wilke told reporters, noting the Seattle-based company is working with regulators to get permission. Amazon is generally working to make more deliveries in one day, half the time it now promises for members of its Prime subscription service. (The Washington Post is owned by Jeff Bezos, CEO of Amazon)

Bezos first announced the company’s plan for drone deliveries in a 2013 TV interview, saying he thought the technology would be ready to go in four or five years. Since then, the only major public update by Amazon was a test in December 2016 in which the company made a customer delivery in the United Kingdom.

Amazon’s latest drone can make vertical liftoffs like a helicopter and pivot to fly horizontally, Wilke said. A video at Amazon’s conference showed the craft making turns over a grassy field and ultimately alighting gently.

The video appeared to indicate the drones require customers to lay out a landing pad with boxy black-and-white scanning images known as QR codes — which look like mini-crossword puzzles — to know where to land.