21. Launched at 9 a . m ., it cruised within feet of the pingers an hour later. 22. Called a " pinger , " the cylinder sets off a radio signal when immersed in water. 23. The boxes are also equipped with sonar " pingers " to help searchers find them in water. 24. First, he said, the sonic pingers that let searchers home in on boxes only function in water. 25. But with a pinger locator, you know which side of the haystack you're looking at ." 26. The results of the PingER Project, including source code, are made available to the public at no cost. 27. Officials said Tuesday that the pinger had been knocked off the flight data recorder, which is actually painted bright orange. 28. But investigators viewing videotape from the Deep Drone noticed the device as wreckage was being cleared to get to the pinger . 29. Investigators noticed the orange-colored box on videotape as the USS Grapple's Deep Drone was targeting the pinger . 30. Investigators say they are in generally good shape but the underwater " pinger " was ripped off the data recorder.
