Last week, Metro introduced free WiFi to six underground stations for a 45-day trial period.

Now, the head of the Federal Communications Commission says that’s not good enough.

The FCC has long been after Metro to hustle the process of bringing cellphone service and free WiFi into the transit system’s underground system. Far more than it being a matter of customer convenience, federal officials argue that it’s a safety issue — riders stuck inside trains during an emergency should be able to communicate with emergency services about what’s going on.

In a letter to Metro General Manager Paul J. Wiedefeld, FCC Commissioner Michael O’Rielly acknowledged that Metro’s temporary WiFi program at underground stations is a step in the right direction, but he can’t understand why the service would be rolled out as a pilot.

“It is my understanding that the project will last 45 days and then be suspended pending evaluation,” O’Rielly wrote. “I am at a loss as to why these critical communications features would be disabled at a set date. The data collected during the test period should be able to be analyzed without turning off the Wi-Fi network.”

O’Rielly used the letter to ask Wiedefeld questions: How and when does Metro plan to make a decision about turning back on the WiFi after the end of the pilot? And how quickly does the agency plan to extend the service throughout all the underground stations in the system?

“Given the overall questionable state of communications capabilities within the entire system, it seems counterintuitive to cease operations of an additional mechanism that the public can use to reach emergency personnel when warranted,” O’Rielly said.

When Metro officials first shared the news about the pilot program, they said in a news release that “Metro customers are encouraged to submit their feedback at the bottom of the home page.  The information will be used to assess the pilot.”

On Monday, Metro spokesman Richard L. Jordan said the agency plans to answer those questions in a formal response to the FCC commissioner. However, he did have one point to make.

“All of Metro’s underground stations are wired for cellular service on all major U.S. carriers,” Jordan said, “making the point about the WiFi pilot moot.”

Read O’Rielly’s letter here.