Dead Reckoning Know how to use dead reckoning techniques.

Turn-and-Slip Indicators Two instruments in one. The turn indicator, which is the needle, indicates the direction of the turn and the rate of turn. The ball in the glass tube (called the inclinometer) indicates the quality of the turn. The turn indicator, which is the needle, indicates the direction of the turn and the rate of turn. The ball in the glass tube (called the inclinometer) indicates the quality of the turn.

Vertical Speed Indicator Tells the pilot at what rate (in feet per minute) the airplane is climbing or descending. It works like an altimeter in that the indication is merely a reflection of atmospheric pressure changes. The more rapid the pressure change, the greater the rate of climb or descent. The needle rotates clockwise to indicate climb, and counter-clockwise to indicate descent.

Attitude Indicator A gyroscopic instrument that provides a horizon that moves about so that it always shows the relationship of the horizon to the pitch (nose up and down), and the bank of the airplane’s wings.

Dead Reckoning Know how to use dead reckoning techniques. 1. List basic facts and general principles of dead reckoning. 2. Describe the wind triangle and its applications. Lesson Objective: Know how to use dead reckoning techniques. Samples of Behavior/Main Points 1. List basic facts and general principle of dead reckoning. 2. Describe the wind triangle and its applications.

Dead Reckoning The basic method of navigation. Navigators of old deduced their position by using the distances and directions that their vessels had gone since passing or leaving a known position. Dead Reckoning (DR) The basic method of navigation. The term comes from ship’s log book’s of early mariners. Navigators of old deduced their position by using the distances and directions that their vessels had gone since passing or leaving a known position. Positions were determined at frequent intervals and were entered in the ship’s log book under a column headed by the abbreviation “ded. pos” for “deducted posposition.” The reckoning necessary to obtain the information for these entries was know as “ded reckoning.” Over the years through popular usage, “ded reckoning” became “dead reckoning.”

Dead Reckoning The major idea behind dead reckoning navigation is to know, by preflight planning and in-flight checking, the position of the aircraft at any given time. Navigation is only as accurate as the information available. The major idea behind dead reckoning navigation is to know, by preflight planning and in-flight checking, the position of the aircraft at any given time. DR navigation enables the pilot or navigator to determine the position of the aircraft and to direct it from place to place. Accomplished by measuring or calculating and keeping account of navigational factors, such as direction, distance, time, wind, and speed. By using a flight plan, a pilot may glance at the information and determine how the flight is progressing.

A Wind A B B

Dead Reckoning The factors used in DR True course (TC) True airspeed (TAS) Wind direction (W) Wind velocity (V) True heading (TH) Groundspeed (GS) The factors used in DR True course (TC) True airspeed (TAS) Wind direction (W) Wind velocity (V) True heading (TH) Groundspeed (GS)

Dead Reckoning To understand how the factors are derived and put to use, you must understand the wind triangle. An aircraft’s movement over the ground is comparable to a boat crossing a river. To understand how the factors are derived and put to use, you must understand the wind triangle. Any vehicle traveling on the ground moves in the direction in which it is steered or headed. Ground vehicles are affected very little by wind. An aircraft seldom travels in exactly the direction in which it is headed. This is caused by the wind effect.

Dead Reckoning The horizontal motion of air over the Earth’s surface is called wind. Wind direction (W) is the direction the wind moves. Wind velocity (V) is stated in knots. Any free object in the air moves downwind with the speed of the wind. The path of an aircraft over the Earth is determined by two factors. The motion of the aircraft through the air mass. The motion of the air mass across the Earth’s surface. The horizontal motion of air over the Earth’s surface is called wind. Wind direction (W) is the direction the wind moves. A wind that blows from the south toward the north has a direction of 180°. Wind velocity (V) is stated in knots. Whenever a wind is reported, the direction and velocity are combined and reported as W/V. For example, a wind from the west blowing east at 20kn is reported W/V, 270°/20kn.

Dead Reckoning The path over the ground is track (TR). True course (TC) is the intended path of the aircraft over the Earth’s surface. TC is future and TR is past. The difference between TR and TH is the displacement of the aircraft caused by the wind (drift). The path over the ground is track (TR). True course (TC) is the intended path of the aircraft over the Earth’s surface. Track is the actual path that the aircraft has flown over the Earth’s surface. TC is future and TR is past. The difference between TR and TH is the displacement of the aircraft caused by the wind. This displacement is called drift. It is expressed as the angle between TH and TR. When an aircraft drifts right, the drift is referred to as right drift. Any given wind will cause a different drift for every heading. If an aircraft were flying a heading of 360° and maintaining a TAS of 120kn, it would have a right drift of 9° with the 270°/20kn wind. If the aircraft turned to a heading of 120° the drift would decrease to approximately 4° and would drift left.

Wind Triangle The wind triangle includes six factors. Three speeds Three directions True Airspeed (TAS) Wind Velocity (W/V) Ground Speed (GS) The wind triangle includes six factors: three speeds and three directions. Problems involving these six quantities make up the major part of dead reckoning navigation.

Working the Triangle

Working the Triangle Aircraft #1 Aircraft #2 TH: 110 TH: 230 TAS 300 TAS: 300 W/V: 200/35 W/V: 180/60 Aircraft #3 Aircraft #4 TH: 015 TH: 180 TAS 400 TAS: 400 W/V: 015/50 W/V: 360/45 TH W/V TC Var MH TAS GS Dist Time ETA Drift 110 - 10 300 38 NM 230 -10 49NM 015 400 110NM 180 230NM

Dead Reckoning Know how to use dead reckoning techniques. 1. List basic facts and general principles of dead reckoning. 2. Describe the wind triangle and its applications. Lesson Objective: Know how to use dead reckoning techniques. Samples of Behavior/Main Points 1. List basic facts and general principle of dead reckoning. 2. Describe the wind triangle and its applications.