1.   Authorities said the pilot of the six-passenger plane radioed the tower that he was turning back.

2.   He assumed that they had already radioed the tower so he advised them to go to the offices of Signature, the private general aviation operator at the airport.

3.   Kraus said Atta and Shehhi told him they had not been aware that they needed to radio the tower for instructions.

4.   The plane was apparently on a test flight when its pilot radioed the Davao City airport tower reporting an emergency, the Air Transport Office in Manila said.

5.   The thief radioed the tower at the Norwood airport Sunday morning requesting permission to take off.