Property of Lear Siegler

1. Property of Lear Siegler

2. NAVIGATIONAL COMPUTER SLIDE RULE

3. Terminal Learning Objective At the end of this lesson the student will: Action: Identify the components of the navigation computer slide rule problems Condition: Given a computer and situational data Standard: In Accordance With (IAW) Field Manual (FM) 3-04.240

4. Enabling Learning Objective (ELO) #1 Action: Identify the scales, values, and spacing of the navigation computer slide rule Condition: Given a navigation computer Standard: IAW FM 1-240

5. SLIDE RULE SCALES Outer Scale: Stationary - Miles, Distance, or Quantity

6. SLIDE RULE SCALES Inner Scale: Rotating - Time or Rate

7. SLIDE RULE VALUES Values: Represent multiples of 10 on either scale, e.g. 70 can represent .07, .7, 7.0, 70, 700, 7000, etc., dependent upon decimal placement.

8. SLIDE RULE VALUES 70 minutes 1 hr, 10 min Time scale values: 70 minutes on the outer ring of the rotating scale can be converted to 1:10 (one hour, ten minutes) on the hours scale on the inner ring of the rotating scale

9. SLIDE RULE SPACING Spacing: spaces between numbers are not constant on either scale. From 60 to 15 (clockwise), unit values are 1. From 15 to 30 (clockwise), unit values are 2. From 30 to 60 (clockwise), unit values are 1/2.

10. DECIMAL PLACEMENT The units between 21 and 22 are represented by 5 spaces. The second unit past 21 can be read as 21.4 or 2140. 21.4 or 2140. Read this as? 74, 7.4, 740 Read this as? 37.5, 375, 3750

11. Questions?

12. Enabling Learning Objective (ELO) #2 Action: Identify components of the slide rule computer Condition: Given a navigation computer Standard: IAW FM 1-240

13. DISTANCE CONVERSION INDICES NAUT index - located at scale value 66, used for converting to nautical miles. STAT index - located at scale value 76, used for converting to statute miles. KM index - located at scale value 122, used for converting to kilometers.

14. INNER SCALE INDICES SPEED index - located at 60 on the inner scale and represented by a large black arrow. It is the hour index. 36 index - located at 36 on the inner scale and represented by a small arrow. It is the second index (divides one hour into 3,600 seconds).

15. INNER SCALE WINDOWS ALTITUDE COMPUTATIONS WINDOW Located immediately to the right of the hour index. True altitude computations. Temperature scale - • Located inside of window. • Temperature range from - 80° C to + 50°C.

16. INNER SCALE WINDOWS ALTITUDE COMPUTATIONS WINDOW True altitude computations. Altitude scale - • Located under temperature window. • Altitude range from -2000 ft to 34,000 ft in increments of 2000 ft, 35,000 ft to 80,000 ft use the same mark.

17. INNER SCALE WINDOWS AIRSPEED COMPUTATIONS WINDOW Located across from the hour index. Used for True airspeed and density altitude computations.

18. INNER SCALE WINDOWS AIRSPEED COMPUTATIONS WINDOW True airspeed computations. Temperature scale - • Located above window. • Temperature range from + 50°C to - 80°C. • Negative temps areright, positive temps are left.

19. INNER SCALE WINDOWS AIRSPEED COMPUTATIONS WINDOW True airspeed computations. Altitude scale - • Located in window. • Altitude range from -2000 ft to 80,000 ft in increments of 1000 ft.

20. INNER SCALE WINDOWS DENSITY ALTITUDE WINDOW Located above airspeed window and used to determine density altitude. • Uses airspeed window to set up temperature and altitude. • Altitude range from - 10,000 ft to 80,000 ft, increments of 1,000 ft.

21. Questions?

22. Enabling Learning Objective (ELO) #3 Action: Compute simple proportion problems Condition: Given a navigation computer and data Standard: IAW FM 1-240

23. PROPORTIONS A simple proportion is a fractional relationship between numbers and is expressed as a ratio. Example: • 20:40 represents a fraction of one-half (reduced to it’s lowest common denominator), or expressed as a ratio, 1:2 (one to two). • 12:16, 12 on the outer scale over 16 on the inner scale is a 3/4 or three to four relationship.

24. Proportions In Problem Solving Problem: • How many pounds are in 120 gallons of JP- 8? Solution: • At least three factors must be known to solve for the unknown (X). • There are 6.7 pounds in each gallon of JP-8. • The three known are: 1. 6.7 lbs. 2. 1 gallon 3. 120 gallons • The ratio is: 6.7 : X 1 120

25. Proportions In Problem Solving Problem: • How many lbs are in 120 gallons of JP- 8? 1. Set 6.7 on the outer scale over 1.0 on the inner scale. 2. Find 120 on the inner scale and read 805 lbs above 120 gallons.

26. Questions?

27. Enabling Learning Objective (ELO) #4 Action: Convert distance measurements Condition: Given a navigation computer and data Standard: IAW FM 1-240

28. Distance Measuring Units Problem: • How many statute miles equals 90 nautical miles? How many kilometers equals 90 nautical miles?

29. Distance Measuring Units Problem: • X SM = 90 NM? X KM = 90 NM? 1. Set 90 NM under the NAUT index. 2. Read 104 SM under the STAT index. 2. Read 166 KM under the KM index.

30. Questions?

31. Enabling Learning Objective (ELO) #5 Action: Determine ground speed Condition: Given a navigation computer and situational data Standard: IAW FM 1-240

32. Ground speed equals distance divided by time. Problem: • What is the ground speed if it takes 35 minutes to fly 80 nautical miles?

33. Ground Speed Problems 1. Set 35 (inner scale) under 80 (outer scale). Problem: • 35 Min to fly 80 NM. GS = X. 2. Read 137 kts (knots) over the speed index, (60 minutes).

34. Ground speed equals distance divided by time. Problem: • What is the ground speed if it takes if it takes 9 minutes to fly 28 kilometers? NOTE! Ground speed is measured in knots (nautical miles per hour). You must convert distance to nautical miles in order to solve for knots!

35. Ground Speed Problems 1. Set 28 under the KM index. Problem: • 9 min to fly 28 KM. GS = X. 2. Read 15.2 NM under the NAUT index. First, convert KM to NM.

36. Ground Speed Problems Problem: • 9 min to fly 28 KM. (15.2 NM). GS = X. 3. Set 15.2 (outer scale) over 9 (inner scale. 4. Read GS, 101 kts, over the 60 index.

37. Questions?

38. Enabling Learning Objective (ELO) #6 Action: Determine time required Condition: Given a navigation computer and situational data Standard: IAW FM 1-240

39. Time equals distance divided by ground speed. Problem: • How much time is required to fly 333 nautical miles at a ground speed of 174 knots?

40. Time Required Problems Problem: • Dis. = 333 NM, GS = 174. Time = X. 1. Set 60 index under 174. 2. Read 115 minutes, under 333. NOTE! 115 min can be read as 1hr, 55 min, on inner scale of rotating scale.

41. Questions?

42. Enabling Learning Objective (ELO) #7 Action: Convert time-distance problems Condition: Given a navigation computer and situational data Standard: IAW FM 1-240

43. Convert Time-Distance Problems Problem: • If 50 minutes are required to travel 120 nautical miles, how many minutes are required to travel 86 nautical miles at the same rate?

44. Time-Distance Problems 1. Set 50 min under 120 NM. Problem: • 50 min. = 120NM X min = 86NM. 2. Read 36 min under 86 NM.

45. Convert Time-Distance Problems Problem: • Your ground speed is 130 knots, you have flown for 1 hour and 20 minutes. How many nautical miles have you traveled?

46. Time-Distance Problems Problem: • GS = 130 knots, 1 hr, 20 min, distance = X 1. Set speed index under 130. 2. Read the distance, 174 NM, over the 1hr, 20 min mark.

47. Questions?

48. Enabling Learning Objective (ELO) #8 Action: Solve rate-time-distance problems using the 36 index Condition: Given a navigation computer and situational data Standard: IAW FM 1-240

49. Solving problems using the 36 index. Used whenever time must be calculated in seconds and minutes instead of minutes and hours. NOTE! Use the 36 index whenever the distance is less than 1/10th of the ground speed.

50. Solving problems using the 36 index. Problem involving less than 60 seconds: • What is the time required if the ground speed is 100 knots and the distance is 0.5 NM?