41.   Three IMUs are not needed for landing, however, and flight controllers were confident Thursday that the spacecraft would land as scheduled.

42.   Voss of the FAA said he believes air traffic controllers will be able to learn the system quickly.

43.   What communications took place between the pilots and air-traffic controllers are unknown.

44.   When there are too few controllers, the lower-level airspace is restricted so controllers can focus on higher altitudes used by jets.

45.   While the independent controller was a cool concept, developers never made much use of it, and the feel was clunkily remniscent of the awkward Atari Jaguar controllers.

46.   A spokesman at Russian Mission Control said ground controllers were unaware of the decision.

47.   A preliminary investigation into the failure suggested that ground controllers at Plesetsk were not to blame, Russian officials said.

48.   A security officer who answered the phone at Tampa International Airport Tuesday night said air traffic controllers were not immediately available to comment.

49.   A preliminary investigation suggested ground controllers at Plesetsk were not to blame, Russian officials said.

50.   But air traffic controllers apparently were unimpressed, and announced a strike starting Friday to back demands for higher pay for qualified staff.