51�Թ�

“The helicopter maintained a low altitude and groundspeed as it maneuvered over the ridgeline for the next few minutes,” the report says.

FAA data indicated that it was descending at a rate of 6,800 feet a minute at a groundspeed of 30 knots before it lost radar contact.

Depending on the direction of the wind, that can be faster or slower than the groundspeed, the plane’s speed relative to the earth.

A330 safely after obtaining groundspeed information from air traffic control and using the jet’s radar altimeter, according to a preliminary report from the Australian Transport Safety Bureau.

In this case, the input consisted of flight information, like the glider’s pitch, yaw, groundspeed, and airspeed.