1 statute mile 120 KIAS  120 KIAS 5,280 ft 400 fps = 12.5 seconds to impact Figure 1-1. Head-on approach impact time. Figure 1-2.  The figure above is a scale drawing of an aircraft climbing at 1,000 fpm, located 1 NM from the end of the canyon and  starting from the canyon floor 1,000 feet below the rim. The time to cover 6,000 feet is 24 seconds. With the aircraft climbing at 1,000  fps, in approximately ½ minute, the aircraft will climb only 500 feet and will not clear the rim.  A c t u a l c l i m b p a t h D e s i r e d c l i m b p a t h 1,000 feet 0  6,076.1 1 nautical mile If a pilot sees an aircraft approaching at an angle and the  aircraft’s relationship to the pilot does not change, the aircraft  will eventually impact. If an aircraft is spotted at 45° off the  nose and that relationship remains constant, it will remain  constant right up to the time of impact (45°). Therefore, if a  pilot sees an aircraft on a converging course and the aircraft  remains in the same position, change course, speed, altitude  or all of these to avoid a midair collision.  aircraft is a nautical mile (NM) (6,076.1 feet) from the canyon  end, divide the one NM by the aircraft speed. In this case,  6,000 feet divided by 250 is about 24 seconds. [ Figure 1-2 ]  In another accident, the instructor of a Piper Apache feathered  the left engine while the rated student pilot was executing  an approach for landing in VFR conditions. Unfortunately,  the student then feathered the right engine. Faced with a  small tree line (containing scrub and small trees less than 10  feet in height) to his front, the instructor attempted to turn  toward the runway. As most pilots know, executing a turn  results in either decreased speed or increased descent rate,  or requires more power to prevent the former. Starting from  about 400 feet without power is not a viable position, and  the sink rate on the aircraft is easily between 15 and 20 fps  vertically. Once the instructor initiated the turn toward the  runway, the sink rate was increased by the execution of the  turn. [ Figure 1-3 ] Adding to the complexity of the situation,  the instructor attempted to unfeather the engines, which  increased the drag, in turn increasing the rate of descent as  the propellers started to turn. The aircraft stalled, leading to  an uncontrolled impact. Had the instructor continued straight  In 2006, a 14 CFR part 135 operator for the United States  military flying Casa 212s had an accident that would have  been avoided with a basic understanding of rate of climb. The  aircraft (flying in Afghanistan) was attempting to climb over  the top ridge of a box canyon. The aircraft was climbing at  1,000 feet per minute (fpm) and about 1 mile from the canyon  end. Unfortunately, the elevation change was also about  1,000 feet, making a safe ascent impossible. The aircraft  hit the canyon wall about ½ way up the wall. How is this  determined? The aircraft speed in knots multiplied by 1.68  equals the aircraft speed in feet per second (fps). For instance,  in this case if the aircraft were traveling at about 150 knots,  the speed per second is about 250 fps (150  x  1.68). If the  Understanding the Glide Distance Understanding the Dangers of Converging Aircraft Understanding Rate of Climb 1-4 Change 1 (January 2016)