Air Force: Tests didn't include troubled GPS unit

(AP) -- The Air Force says it performed no advance testing on the specific type of military GPS receiver that had problems picking up locator signals after a change in ground-control software.

The Air Force said Monday that it performed tests on other equipment, but none of it contained the type of receiver that was unable to lock on to Global Positioning System satellites after the change.

The manufacturer of the receivers, Trimble Advanced and Military Systems, says it did run advance tests and found no problems.

An Air Force spokesman says its testers didn't have any samples of the affected receiver. He says the Air Force is now acquiring a more representative sample of GPS receivers that are in use.

The problem occurred in January, and the Air Force says it has been fixed.