The Federal Communications Commission is considering a plan to route U.S. emergency 911 location calls through a Russian satellite system, raising national security alarms inside a Congress dubious of Moscow’s intentions.

In a proposal before the FCC, the 911 emergency system would rely on the Russian Federation’s GLONASS precision navigation and timing satellite system to locate people calling 911 from their mobile phones.

If the plan is enacted, Russia may have the ability to impair America’s 911 emergency capabilities and could use it as a tool to spy on the whereabouts of first responders among other things, legislators warn.

“In view of the threat posed to the world by Russia’s Vladimir Putin, it cannot be seriously considered that the U.S. would rely on a system in that dictator’s control for its wireless 911 location capability,” Rep. Mike Rogers, Alabama Republican and chairman of the Armed Services subcommittee on strategic forces, wrote in a letter to the secretary of defense and director of national intelligence.

“Our response to Russia’s hybrid warfare, arms control cheating, illegal invasions of sovereign nations, and energy-based extortion must be broad-based isolation and counter-leverage,” Mr. Rogers said in the letter, which was obtained exclusively by The Washington Times.

Wireless carriers AT&T Mobility, Sprint, T-Mobile USA and Verizon crafted the plan along with the Association of Public Safety Communications Officials and the National Emergency Number Association in hopes of improving the ability of police, firefighters and medics to locate people who use their mobile phones to call for help.

Use of multiple systems improves the ability to pinpoint a signal’s source exactly, said Trey Forgety, director of government affairs for the National Emergency Number Association, going on to note that the Russian satellite system is superior to the European and Chinese alternatives for various reasons.

“If you have good use of the sky and both satellites, you have better accuracy,” he said. “Our view is that we ought to be leveraging anything that is available to find someone in an emergency.”

Cellphone users who dial 911 from inside a building in urban areas are more difficult for first responders to find because the GPS technology on cellphones does not work as well indoors as it does outdoors, according to published reports.

In defense of the industry’s plans, Sprint said it would keep the use of the Russian satellites to a minimum, thus reducing the national security threat.

“The roadmap does not envision that carriers will rely exclusively on the GLONASS system,” Ray Rothermel, Sprint’s director of government affairs, said in a Dec. 24 letter to FCC officials. “Rather, the roadmap advocates taking advantage of a tool that is available now to allow carriers to improve location information.”

Army Col. Steve Warren, a Pentagon spokesman, declined to discuss concerns raised in the congressional letter but said the Defense Department would be sure to address them.

“Secretary Hagel places a high priority on working closely with Congress and will answer as quickly as possible,” he said. “As a matter of policy, we do not release the secretary’s congressional correspondence.”

Nikolay Liashenko, a counselor for the Russian Embassy in Washington, had no comment Wednesday evening.

Mr. Rogers asked the Department of Defense and DNI to detail the extent to which they would rely on the 911 system for communications and the effect on national security users and first responders if Russia provides the satellite communications.

Use of multiple systems improves the ability to pinpoint a signal’s source exactly, said Trey Forgety, director of government affairs for the National Emergency Number Association, going on to note that the Russian satellite system is superior to the European and Chinese alternatives for various reasons.

“If you have good use of the sky and both satellites, you have better accuracy,” he said. “Our view is that we ought to be leveraging anything that is available to find someone in an emergency.”

Cellphone users who dial 911 from inside a building in urban areas are more difficult for first responders to find because the GPS technology on cellphones does not work as well indoors as it does outdoors, according to published reports.

In defense of the industry’s plans, Sprint said it would keep the use of the Russian satellites to a minimum, thus reducing the national security threat.

“The roadmap does not envision that carriers will rely exclusively on the GLONASS system,” Ray Rothermel, Sprint’s director of government affairs, said in a Dec. 24 letter to FCC officials. “Rather, the roadmap advocates taking advantage of a tool that is available now to allow carriers to improve location information.”

Army Col. Steve Warren, a Pentagon spokesman, declined to discuss concerns raised in the congressional letter but said the Defense Department would be sure to address them.

“Secretary Hagel places a high priority on working closely with Congress and will answer as quickly as possible,” he said. “As a matter of policy, we do not release the secretary’s congressional correspondence.”

Nikolay Liashenko, a counselor for the Russian Embassy in Washington, had no comment Wednesday evening.

Mr. Rogers asked the Department of Defense and DNI to detail the extent to which they would rely on the 911 system for communications and the effect on national security users and first responders if Russia provides the satellite communications.