The Liberty Incident

Critical Seconds

When an aircraft approaches a target, how much time does a pilot have to identify the target?

FAA VFR Pilot Exam-O-Gram No. 29, using calculations from the U.S. Naval Aviation Bulletin, published a "Critical Seconds, Distance, Speed, and Time" chart to inform pilots of the time/distance elements at speeds of 360 MPH and 600 MPH. Notice that from one mile away, a pilot flying at 600 MPH is 6 seconds from a target and a pilot flying at 360 MPH is 10 seconds from target. At one half mile, the time element is reduced to between 3 and 5 seconds.

The chart is produced as it appears in the FAA Exam-O-Gram and then split in order to present larger text for easier reading.


Download FAA Critical Seconds Chart


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