EQUATIONS

Question 1

To find Distance:
D=GS X T

Answer 1

Example:
GS= 90 Knots
T= 30 minutes (.5 hrs)
D= 90 x .5 = 45 NM

Question 2

To find Time: T=D/GS

Answer 2

Example:
D= 30NM
GS=100 Knots
T= 30/100
T=.3 hrs
(.1 hr= 6minutes)
.3 x .6 = 18 minutes

Question 3

To find Ground Speed GS= D/T

Answer 3

Example D=50 NM
T= 25 Minutes
GS= 50/25 = 2 NM per min
2 NM per min x 60 mins=
120 NM

Question 4

NM per min (NM/Minute):

Answer 4

NM/Min = TAS/60
Example: TAS= 120 KTS
120/60 = 2 NM per minute

Question 5

To quickly determine nautical mile per minute:

Answer 5

round your airspeed to the nearest 10, drop the zero and divide by 6
Example:
TAS= 178 KTS (180 KTS)
Drop the zero & decide by 6
18/6=3 NM per min

Question 6

To find distance, using NM per minute:

Answer 6

Example: time since last checkpoint =12 min
TAS (no wind) = 180 knots
NM Per minute = 3
12 minutes x3 = 36 NM

Question 7

Minutes per nautical mile:

Answer 7

Minutes per NM =60/TAS
Example: TAS= 100 kt
Mins/NM = 60/100 = .6

Question 8

To find ETE using minutes per nautical mile:

Answer 8

Example: distance on chart= 20 NM
TAS = 100 Knots
Min/NM = .6
20 x .6 = 12 mins

Question 9

One finger equals approximately five nautical miles on the sectional aeronautical chart. Quickly estimate time to a point on the chart count the number of fingers then use minutes/NM.

Answer 9

TAS= 100kt
Minutes/NM = .6
.6 X 20NM = 12 minutes ETE

Question 10

To determine fuel burn ( gallons per hour):

Answer 10

Gallons per hour = gallons used/hours flown
Example: duration of flight = 2 hours
Gallons used = 18 gallons
18/2 = 9 gallons per hour
(it is a good idea to check the actual fuel burn of the aircraft you were flying and compare it with the AFM!)

Question 11

To determine aircraft endurance:

Answer 11

Endurance = usable, fuel/fuel burn
Example: useable fuel = 40 gallons
Fuel burn = 8 gallons per hour
40/8 = 5 hours endurance (no reserve)

Question 12

To determine remaining time:

Answer 12

Time remaining = fuel, remaining/fuel burn
Example: fuel remaining = 24 gallons
Fuel burn = 8GPH
24/8 = 3 hours remaining

Question 13

To calculate NM per gallon:

Answer 13

NM/gallon = NM flown/gallons used
Example: distance flown = 200NM
Gallons used = 25
MPG = 200/25 = 8NM per gallon

Question 14

To determine fuel required:

Answer 14

Fuel required = time on route x fuel burned
Example: time on route = 2 hours
Fuel burn = 8 gallons per hour
8×2 = 16 gallons required (plus reserves)

Question 15

VHF reception distance NM

Answer 15

1.25x square root of altitude AGL