Navigation Level 1: Dead Reckoning

�For long stretches where there were no landmarks, they flew a heading and hacked a stopwatch, which was called dead reckoning�.

 

1.      Know the basic performance specs of the aircraft you are flying:

a.       MODEL: Cessna C172SP Skyhawk

b.      MAX RANGE: 352 to 518 nm

c.       CRUISE SPEED: about 100 to 110 KIAS

d.      STALL SPEED: 50 KIAS w/o flaps, 43 KIAS w flaps

e.       BEST GLIDE SPEED: 68 KIAS

f.       SERVICE CEILING: 14,000 ft

g.      ENGINE POWER: 180 hp

h.      EMPTY WEIGHT: 1676 lbs

i.        USEFUL PAYLOAD: 881 lbs

j.        WING SPAN: 36 ft

k.      FUEL TANK: 56 gal

 

2.      Know the basic units involved:

a.       nm = Nautical Mile (the circumference of the Earth is divided into 360 degrees from the center, and each degree is further divided into 60 minute angles. A minute angle is equivalent to a nautical mile). A nautical mile is �just a bit longer� than a �regular� mile. Its about 1.15 times a regular mile. So 518 nm (the max range of the Cessna SP) is about 596 mi.

b.      KIAS = Knots Indicated Air Speed. A knot is �1 nm per hour�. So the Cessna�s cruise speed (being about 110 KIAS) is equivalent to about 127 mph.

 

3.      Know how to interpret the numbers on the Heading Indicator and Runway Designation Marking:

a.       The compass rose in aviation designates North as 0 degrees (or 360 degrees), with degrees increasing clockwise. So East is 90 degrees, South is 180 degrees, etc.

b.      The Heading Indicator (HI) drops off the last zero from these readings, so it looks like 36 degrees make a full circle (North = 0, East = 9, South = 18, West = 27, and North again = 36).

c.       The Runway Designation Marking shows the heading you would be facing if you were landing or taking off on that runway. So for a runway marked �30�, in order to land at that runway you�ll need to be flying a heading of 300 degrees as indicated on the HI.

 

4.      Using some kind of Flight Planner software (such as Plan G), pick out the airports you would like to fly to along your route, and set the airspeed to your likely cruising speed (for the Cessna, I choose about 90 KIAS). You will get a calculated table that looks like the following example:

 

5.      To simplify the flight plan (using the above example), you could reduce it to its critical information:

 

6.      To use this flight plan while flying, you�ll need a stopwatch, because timing is a critical factor in following this plan (each leg has the time indicated in the Time column of the flight plan, in minutes).