At the site in the Cambridge countryside, and a similar facility in Canada, Amazon is likely to be working on the droneâs sensors and other improvements needed for its daily use.
A company spokeswoman declined to comment on the English test site.
With competitors aplenty, it is not surprising that Amazon wants to hide efforts from prying eyes. In Fulbourn, the nearest village to the test site, where thatch-roofed houses and a centuries-old church stand guard over the quiet main street, few people even knew that the American technology giant had moved in down the road.
Credit Andrew Testa for The New York Times
âDrones? Here?â said Linda McCarthy, who was taking her two Labrador retrievers for their morning walk as I trudged by on a public footpath with a map of the area and a pair of decades-old binoculars. âIâve never heard anything about that.â
Some people in this rural area have had angry reactions. To Julia Napier, a co-founder of Friends of the Roman Road and Fleam Dyke, a local association that maintains public footpaths around the site, Amazonâs arrival is a potential threat to local wildlife and the wider countryside, something the company has denied.
Over coffee and surrounded by wildlife maps of the area, Ms. Napier, 78, complained that Amazon had not consulted many local residents about its tests. She questioned what right the company had to fly across the British countryside, possibly without the permission of landowners, even though such authorization may not be required.
Ms. Napier refuses to use Amazonâs services, preferring to visit her local bookshop or smaller online British rivals.
Her stance against the e-commerce giant has not gone unnoticed. A company employee called last week, Ms. Napier said, trying to persuade her that the local drone trials were safe and did not pose a risk to wildlife.
As consumer and commercial drones increase in popularity, the government is taking more steps to address safety concerns and regulate the aerial vehicles.
She remains skeptical.
âThey are testing those drones here because they canât do it in America,â she said. âWhatever the Americans donât want, I donât want it, either.â
Rumors about mysterious aircraft flying low across the countryside drew me to the area. Yet pulling up in a nearby parking lot on an unseasonably warm September morning, I felt as if I was in the wrong place.
Nothing looked out of the ordinary. Commuters arrived at a rural office park and dog walkers basked in the late-summer sun. And as I walked miles (I ended up covering the distance of a half-marathon) along a Roman road built roughly 2,000 years ago â now a grassy public footpath â I was no closer to finding the elusive machines.
My ears pricked up to every noise that broke the rural tranquillity, only to be disappointed when the buzzing turned out to be a tractor, car or just a swarm of bees flying in the midday sun. Returning to my car after exhausting almost all the public footpaths, I had a sinking suspicion I was on a wild-goose chase.
Only one route remained.
Less than 300 yards down the grassy track on the edge of a farm, a security guard with a walkie-talkie popped up from behind a hedgerow and pointed to a sign declaring: âPrivate property. No trespassing.â
Credit Andrew Testa for The New York Times
When he repeatedly told me this was indeed private property and that he had called the farmer to evict me, I knew I was onto something. As I circled the property with Andrew Testa, a photographer for The New York Times, my suspicions only grew.
At the entrance to the farm â despite Amazonâs presence, farm work was still underway â a security guard in a fluorescent vest was checking the identifications of people arriving at the site. In the distance, hay bales were piled at least 20 feet high (presumably to test the dronesâ ability to navigate between buildings). A large, metallic blue platform in a far-off field provided a panoramic view of the surrounding farmland.
Then we spotted it.
Actually spying the drone â best seen through my colleagueâs long camera lens â was an anticlimax. Instead of performing a series of aerial acrobatics, the device merely bobbed along for about 20 minutes, slowly working its way from one side of the field to the other with barely a waver or shudder.
The stakes for Amazonâs drone test are unquestionably high. The next day, a police officer questioned my colleague as he again photographed the area, though the officer denied that Amazon had tipped him off.
For places like Worsted Lodge â a sparsely populated area where farm animals easily outnumber residents â drones could fill an underserved niche of people with limited access to stores. But in many built-up urban areas, the arrival of drone delivery could quickly become a logistical nightmare â something the tests in the Cambridgeshire countryside would not soon solve.
âHow will deliveries do the last 100 yards?â said Jay Bregman, the founder of Verifly, a drone insurance start-up, when I called him for advice about the practicalities of such plans. âIn places like New York, thatâs going to be really difficult.â