BAE Systems successfully converted its 300th F-4 Phantom fighter jet into an unmanned flying drone for the Air Force, according to a company statement.

Once the F-4s are converted into drones, they receive the operational designation of QF-4. The Air Force converts the aircraft into unmanned aerial vehicles (UAV) to primarily use them for target practice and aircraft training. The conversion process takes about six months.

BAE Systems spokesman Neil Franz said yesterday the cost of converting an F-4 into a QF-4 changes every year and varies according to how many aircraft are modified per year. Franz added the cost of each modification also varies according to the condition of the F-4 and how much work is needed. Once the conversion is complete, Franz said the aircraft is flown manually to Tyndall AFB, Fla., by a BAE pilot.

There are 14 more QF-4s scheduled for delivery by the middle of 2013. Franz said the next delivery is currently scheduled for next week.

The QF-4 program is a 16-year long program. Franz said there have been three contracts awarded over the last 16 years with the last contract awarded in 2004 with options each year.