MARINE CORPS AIR STATION MIRAMAR, Calif. -- Keeping track of the sky's highways is no easy task for the Marines of Marine Corps Air Station Miramar's Air Traffic Control Tower.

The group of Marines who man the 115-foot tower boast that their job leaves little to no room for human error, explaining why they train around the clock.

The Marines keep track of numerous fixed and rotary-wing aircraft housed by the 17 flying squadrons stationed here, in addition to other aircraft that fly within Miramar's airspace at any given time.

"We go to military occupational school for three months, and during that time we learn all the basics," said Sgt. Colin E. Oliva, tower supervisor. "Upon completion of the school, we go to our duty station where the training continues."

For these Marines everyday is a training day.

According to Oliva, the air traffic controllers learn a variety of different techniques depending on the air station to which they're assigned.

"Every facility has different runways and aircraft," Oliva explained. "Therefore, you have to qualify for each station's facility. The training is on-going through your entire time here."

Staff Sgt. Greg L. Guthrie, radar supervisor, explained that Miramar includes two runways and can land just about every kind of aircraft here.

There are several different positions that each Marine must master during their time in the station's tower.

Oliva explained that the tower supervisor makes sure operation goes according to plan and by rules and regulation.

He mentioned that the north and south local control positions clear aircraft for take-off and landing within Miramar's air space consisting of a 3,000 feet to five-mile radius.

He also explained that the flight data position assists local controllers and grants permission for aircraft to enter and land within the station's airspace.

The last position Oliva explained is the ground control position, which is responsible for talking to pilots while on ground and preparing for take-off.

Although the operation tempo has decreased since the squadrons' deployment overseas in Operations Enduring and Iraqi Freedom, the Marines of the Miramar's Air Traffic Control Tower are still hard at work, training around the clock.

"Everyday is an emergency for us," Oliva confessed. "Everything we do is looked at through a magnifying glass Ñ one mistake on our part could cost a life and we can't allow that to happen."