TOPEKA, Kan. -

Fuel is a key component in the Nation's war effort and every military mission. Kansas is home to one of the largest air refueling units in the world.

It's not often you get to look out of plane's window and see an Air Force pilot looking back. Let alone a Thunderbird as it fuels up in flight.

But when you work on a refueling crew with the 190th out of Forbes Field in Topeka, it's just another day at the office.

"In order for us to get done anything around the world, we have to have air refueling," said Kansas Air National Guard Tech Sergeant James Whisenhunt. "We refuel constantly in theater and we also refuel air craft to and from theater. And on a daily basis we air refuel here in the United States."

It takes a crew of three, the boom operator and two pilots, to get the job done.

Each KC-135 can deliver 1000 gallons or about 7000 pounds of fuel each minute.

"Between the Guard and the Reserves we do about 57% of air to air refueling throughout the world," said Kansas Air National Guard Major Joe Blubaugh.

Tankers are the oldest fleet in the Air Force and will soon be replaced by a newer model. The KC-46.

McConnell Air Force base in Wichita will house the new planes, but right now the 190th in Topeka is not a selected site. But it is in the running for three other new tanker sites yet to be chosen.

While Forbes Field waits for that answer, this Kansas National Guard Air Refueling Unit will keep doing it's job to help the Military's mission.