Amazon is arguing that the Federal Aviation Administration took so long to approve its test drone, the model in question has become obsolete. It said as much during a Tuesday testimony before a Senate subcommittee.

“While the FAA was considering our applications for testing, we innovated so rapidly that the [drone] approved last week by the FAA has become obsolete,” said Paul Misener, Amazon’s vice president for Global Public Policy. “We don’t test it anymore. We’ve moved on to more advanced designs that we already are testing abroad.”

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The FAA took a year and a half to approve Amazon’s particular drone model, which is a lengthy amount of time in the technology world. According to Misener, it’s only the U.S. that has given Amazon this amount of hassle.

“Nowhere outside of the United States have we been required to wait more than one or two months to begin testing, and permission has been granted for operating a category of UAS [unmanned aircraft system], giving us room to experiment and rapidly perfect designs without being required to continually obtain new approvals for specific UAS vehicles,” he said during the hearing.

See also: Why Commercial Drones Are Stuck In Regulatory Limbo

Commercial drones have been locked up in regulatory limbo in the United States ever since their invention. It’s a far cry from other countries, where drones are being deployed and tested at much faster rates. According to an FAA spokesperson speaking to ReadWrite, this is a response to the especially complicated U.S. aviation market, which includes both commercial carriers and a vast number of private aircraft:

We recognize industry’s urgency and understand the many amazing applications for UAS technology. However, the United States has the largest, most complex airspace in the world with—unlike other countries—a large general aviation fleet that we must consider when planning UAS integration, since those aircraft and small UAS may occupy the same airspace. Also, different laws and regulatory structures in other nations may allow them to act more quickly to approve certain UAS operations.

The spokesperson went on to say it was necessary for the FAA to have knowledge of exact makes and models of commercial drones in order to correctly assess them. That’s why the FAA claims it can’t approve a category of drones, just individual models.

Everything we do is safety-oriented, and we base our approvals for unmanned aircraft operations on an assessment of the risks to other aircraft and to people and property on the ground. To make that risk assessment, we need sufficient information on a company’s planned operations and aircraft, and we have been working diligently with Amazon to get the information we need.

The FAA is fighting against the tide of public opinion to correct “misconceptions and misinformation about unmanned aircraft system (UAS) regulations.” In an article published last year, the organization responds to assertions such as “Myth… The FAA is lagging behind other countries in approving commercial drones.”

Responses from the FAA don’t seem to be placating drone advocates. Senator Cory Booker (D-NJ) is the latest lawmaker to suggest introducing temporary legislation to speed up the commercial use of drones. He aptly calls it the “Commercial UAV Modernization Act.”

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