## Objectives

- The students will discover the importance of a clock as a flight instrument.
- The students will compute flight time requirements.
- The students will determine the airplanes position.
- The students will compute ground speed and fuel consumption.

## Background Information

The clock is one of the most useful of the flight instruments. It is used in figuring such important items as the time required for a flight, the average ground speed, and determining the airplanes position. All these are more crucial in aviation than in ground transportation.

Military Time is measured in twenty-four hour units. The unit begins at 0001 hours after midnight and continues to the following midnight which is 0000 hours. Twelve oclock noon is 1200 hours. Time after noon begins at 1300 hours and continues to midnight.

Standard Time | Military Time |
---|---|

9:00 a.m. | 0900 hours |

10:30 a.m. | 1030 hours |

12:00 noon | 1200 hours |

1:15 p.m. | 1315 hours |

6:49 p.m. | 1849 hours |

10:30 p.m. | 2230 hours |

12:00 p.m. | 0000 hours |

Standard Time | Military Time | Standard Time | Military Time |
---|---|---|---|

1:40 a.m. | 12:30 p.m. | ||

5:16 p.m. | 11:49 p.m. | ||

7:39 p.m. | 2:32 p.m. | ||

6:47 p.m. | 12:20 p.m. | ||

8:35 p.m. | 11:43 p.m. |

Standard Time | Military Time | Standard Time | Military Time |
---|---|---|---|

0430 hours | 2041 hours | ||

1619 hours | 1022 hours | ||

0003 hours | 2347 hours | ||

1317 hours | 0103 hours | ||

2148 hours | 1508 hours |

Time Required for a Flight:

Example: What will be the length of a flight of 329 miles at an average speed of 94 MPH?

Solution: Divide 329 by 94 equals 3 ½ hours (3 hours, 30 minutes).

Distance | Average Ground Speed | Time |
---|---|---|

275 miles | 100 MPH | |

180 miles | 45 MPH | |

585 miles | 130 MPH | |

2475 miles | 275 MPH | |

1875 miles | 600 MPH | |

195 miles | 65 MPH | |

230 miles | 100 MPH |

What is the length of a flight of 450 miles at an average speed of 90 MPH?

A plane flies 370 miles at an average ground speed of 95 MPH. What time is required for the flight?

Average Ground Speed: The problems in this section are applications of the familiar Time, Rate, and Distance formulas which can be used in problems of automobiles and trucks as well as aircraft. Average ground speed is the RATE in these problems:

RATE X TIME = DISTANCE

DISTANCE DIVIDED BY TIME = RATE

DISTANCE DIVIDED BY RATE = TIME

Example: What is the average ground speed for a flight of 400 miles in 3 hours, 20 minutes?

Solution: Divide 400 by 3 1/3 hours.

Distance | Time | Average Ground Speed |
---|---|---|

285 miles | 3 hours | |

780 miles | 6.5 hours | |

800 miles | 5.33 hours | |

1260 miles | 4 hours 40 minutes | |

2875 miles | 6 hours 15 minutes | |

675 miles | 4.5 hours | |

594 miles | 3 hours 18 minutes | |

245 miles | 2 hours 27 minutes |

What is the ground speed for a flight of 595 miles in three and one-half hours?

An airplane flies 1104 miles in 4 hours, 36 minutes. What is the average ground speed?

Fuel Consumption: Having plenty of gasoline is more important in aviation than in driving a car. The pilot must be able to plan his/her flight to have more fuel than he/she needs. The pilot figures the amount of gasoline the plane should use, and adds a reserve for emergencies. A fuel reserve of 25% is usually allows.

1.Figuring the amount of fuel without a reserve:

Example: How much gasoline will be used in a flight of two hours, twenty minutes if the engine uses six gallons per hour?

Solution: Change two hours, twenty minutes to 140 minutes.

To find the amount of fuel used. ( 140/60)*6=14 gallons .

Flying Time | Fuel Consumption Per Hours | Amount of Fuel Used |
---|---|---|

3 hours 30 minutes (3.5) | 6 gallons | |

5 hours 20 minutes (5.33) | 12 gallons | |

4.5 hours | 5 gallons | |

6 hours 10 minutes (6.17) | 40 gallons | |

2 hours 24 minutes (2.4) | 5 gallons | |

3 hours 12 minutes (3.2) | 15 gallons | |

5 hours 5 minutes (5.08) | 18 gallons |

How much gasoline will be consumed in a flight of three hours, forty minutes if the engine uses nine gallons per hour? (3.67 X 9 = ?)

An airplane makes a flight of six hours, forty-two minutes. The engine uses an average of 18 gallons of gasoline per hour. How much gasoline will be consumed during the flight?

Figuring the amount of fuel needed with a percentage reserve:

Example: How much gasoline will be needed for a flight of four hours, twenty minutes if the engines uses nine gallons per hour, and a fuel reserve of 25% is desired?

Solution: Change four hours, twenty minutes to 4.33 hours. Multiply 4.33 by 9 to find the amount of fuel to be used. 4.33 X 9 = 38.57 gallons.

Since a fuel reserve of 25% is to be carried, 38.57 gallons = 75% of total fuel to be carried. Divide 38.57 by .75 to find 51.96 the total amount of fuel.

Flying Hours | Fuel Consumption Per Hour | Amont of Fuel Used | Amount to Include 25% Reserve |
---|---|---|---|

3 hours 40 minutes | 9 gallons | ||

2 hours 30 minutes | 8 gallons | ||

2 hours 24 minutes | 5 gallons | ||

4 hours 20 minutes | 12 gallons | ||

6 hours 50 minutes | 24 gallons |

Flying Time | Fuel Consumption Per Hour | Amount of Fuel Used | Amount to Include 20% Reserve |
---|---|---|---|

4 hours | 6 gallons | ||

3 hours 30 minutes | 9 gallons | ||

8 hours 20 minutes | 15 gallons | ||

4 hours 10 minutes | 18 gallons |