WASHINGTON -- The Air Force is mulling the fate of decades-old surveillance planes housed near Warner Robins -- and sending Georgia's lawmakers on Capitol Hill into a tizzy.

Air Force Secretary Heather Wilson recently teased that an announcement about the future of the aircraft known as the E-8C Joint Surveillance Target Attack Radar System, or JSTARS, could come by the end of the month. The evaluation has the state's representatives sweating over the potential impact at one of Georgia's major military installations.

The planes -- old 707 passenger aircraft upgraded with high-grade radar and surveillance equipment -- are housed exclusively at Robins Air Force base in middle Georgia. They've been used heavily in the fight against the Islamic State in Iraq and Syria.

But the aircraft are getting old, and technology has advanced. The Air Force has long had plans to upgrade the fleet of 16 planes, but there has recently been some back and forth with Capitol Hill about whether that's the best step forward.

The Air Force told Defense Secretary James Mattis last month that the service was mulling alternatives to JSTARS that would perform similar surveillance functions, according to the trade publication Flight Global. 

That news has riled up members of Georgia's congressional delegation, who in recent years have beat the drum against any suggestion that the Pentagon retire the planes and shutter a key mission at Robins, which  could make the base more susceptible to closure.

They have slipped language into recent defense policy bills banning the Pentagon from spending any money on the retirement of JSTARS -- or even preparing for retirement. And most recently, several members of the delegation penned a searing letter to Mattis excoriating the possibility that the Air Force could be eyeing other options to retrofitting the planes.

“There is no alternative for JSTARS and indicators of its retirement are unacceptable," the lawmakers wrote. "Without this capability, we greatly diminish our nation’s airpower and reduce our combat strength.”

Wilson recently said JSTARS are a "great aircraft, a great concept but technology has moved on," per Flight Global. "Everything now is a sensor. If an F-35 can send its picture and its radar on an image to another aircraft and we're also pulling all that down to a battle station in the middle east, why can't we distribute it? We can do better than this with a network."

The Pentagon currently has plans to retool the entire fleet by the late 2020s, and the Air Force issued a request for proposals last year. Defense contractors Boeing, Lockheed Martin and Northrup Grumman have applied. All three have presences in Georgia.

Read more: Georgia lawmakers defend surveillance plane based in Warner Robins