Time

Question 1

The basic unit of time is known as the ….. ….. …..

Answer 1

mean solar day

Question 2

A solar day doesnt quite correspond to …..

Answer 2

a solar day becasuse the earth moves forward as it rotates

Question 3

Since the speed of the earths rotation varies so does the ……

Answer 3

length of a mean solar day throughout the year

Question 4

Time measured at a meridian is reffered to as

Answer 4

LMT

Question 5

Because all meridians are different we work time into ….. …..

Answer 5

time zones

Question 6

Eastern Australia uses the ….. meridian

Answer 6

150⁰E

Question 7

Central Australia including Broken Hill uses the ….. meridian

Answer 7

142⁰30’E

Question 8

Western Australia uses the ….. meridian

Answer 8

120⁰E

Question 9

The earth rotates 360⁰ per day so it travels ….. per hour

Answer 9

15⁰

Question 10

Define how to work out how many hours from UTC a meridian is

Answer 10

Take the meridians location eg 150⁰

Divide the meridian by 4⁰

this will give you the hours ahead or behind UTC

EG

150⁰E / 15⁰ph = 10 hours ahead of UTC

Question 11

Converting a meridians location to hours is known as ….

Answer 11

Arc to Time Conversion

Question 12

In aviation how big is the date time group?

Answer 12

usually just 6 figures since the year and month are said to be understood

Question 13

BOD / EOD

Define ‘Civil Twilight’

Answer 13

it is the time before sunrise and after sunset when the sun is within 6⁰ of the observers horizon

Question 14

Define ‘Astronomical Twilight’

Answer 14

this extends to 18⁰ below the observers horizon

Question 15

BOD commences when …..

Answer 15

at the commencement of civil twilight

Question 16

EOD occurs at the end of …..

Answer 16

civil twilight

Question 17

at latitudes other than the equator the suns apparent path is …..

Answer 17

inclined from the vertical angle equal to the observers latitude and is never exactly overhead

Question 18

Twilight

The inclination of the suns apparent path at ….. ….. means that it has to travel a …… ….. and takes ……

Answer 18

higher latitudes means that it has to travel a greater distance and takes longer

Question 19

Twilight

At the equator the duration of twilight is …. …. and darkness follows about ….. ….

Answer 19

very short and darkness follows about 10 minutes after sunset

Question 20

In the southern hemispher:

In summer the sun rises …. …..

In winter the sun rises …. ….

At the equinox …..

Answer 20

Summer = further south of east

Winter = Further north of east

At the equinox it is exactly in the east but never exactly overhead because of the latitude

Question 21

Because the earth tilts toward and away from the sun during the various seasons the BOD and EOD will occur at ….. LMTs for the same locations on different dates

Answer 21

different

Question 22

also because of the earths tilt BOD and EOD may be ….. for different locations on the ….. …..

Answer 22

different for different locations on the same date

Question 23

The winter solstice is the …. ….. of the year and occurs around ……

Answer 23

shortest day of the year and occurs around the 20th or 21st of June

Question 24

The summer solstace is the …… day of the year and occurs around the ……

Answer 24

longest day of the year and occurs around the 21st or 22nd of December

Question 25

Which days caus the greatest variation of BOD and EOD for different locations/

Answer 25

the solstice

Question 26

The spring and Autum equinox occur .....

Answer 26

spring = September 22nd or 23rd Autumn March 20th 21st

Question 27

During the spring and autumn equinox what happens to the days and nights?

Answer 27

They are of equal length and every location on earth experiences the BOD and EOD at the same LMT

Question 28

Why dont the solstice's occur at the same date each year?

Answer 28

It is because there is not an exact whole number of days in a year because of the earths orbit around the sun.

Question 29

On the BOD and EOD graph the point where all the lines converge is known as the .....

Answer 29

Equinox and represents the time when BOD and EOD is the same everywhere

Question 30

On the BOD and EOD graphs the greatest seperation in lines means ......

Answer 30

The time when the solistace is occuring

Question 31

Describe the matrix to find BOD ......

Answer 31

1. Find the date 2. Find the latitude 3. Note the LMT 4. Convert the longitude - Arc to time 5. Subtract the Arc to Time conversion from LMT 6. You have UTC 7. Convert the UTC to LMT by adding EST, CST or WST

Question 32

During winter in the southern hemispher the LMT of EOD would occur earlier at the destination than at the departure point for a flight which travels .....

Answer 32

South

Question 33

The duration of daylight experienced by the occupants of an aircraft is less than experienced at the departure point for a flight which travels .....

Answer 33

East

Question 34

For a flight which travels south in the southern hemisphere on the autumn equinox the LMT of EOD would occur at .... ..... ..... at the ..... as the ..... .....

Answer 34

the same time at the destination as the departure point at the equinox the EOD and BOD is the same at all latitudes

Question 35

Places on the same meridian will always have te same LMT for BOD on any given day T/F

Answer 35

False this only occus at the equinox

Question 36

Places on the same parallel of latitude will always have the same LMT for BOD on any given day T/F

Answer 36

True The only factors that determin the BOD are latitude and date

Question 37

The longest night of the year occurs at .....

Answer 37

the winter solistace

Question 38

The LMT of BOD would be earlier at the destination than at the departure point in the southern hemisphere for a flight which travels .....

Answer 38

south in summer If the LMT of BOD gets earlier the days are getting longer. This occurs as you travel south in the summer

Question 39

Morning civil twilight commences when .....

Answer 39

the sun is 6⁰ below the horizon

Question 40

The duration of the periof of twilight .....

Answer 40

increases as latitudes increase

Question 41

The longest day of the year is the ....

Answer 41

summer solistace

Question 42

The passengers and crew of a flight which travels east on a given date will experience ..... hours of daylight than the people at the .....

Answer 42

fewer hours of daylight than the people at the departure point and the destination

Question 43

The time taken to cross 2 consecutive meridians is .....

Answer 43

4 minutes The earths rotates 360⁰ in 24-hours. That's 15⁰ every hour. 15⁰ into 60 minutes = 4 minutes per degree.

Question 44

As you fly south in winter the days get .....

Answer 44

shorter

Question 45

As days get shorter the EOD would be sooner in Sydney/Cairns and therefore later in Sydney/Cairns

Answer 45

Sydney then cairns

Question 46

A day VFR flight should not depart if the planned ETA at the destination is later than .....

Answer 46

10 minutes before the EOD AIPENR 1.2.1

Question 47

The occupants of an aircraft will experience more hours of daylight than the people at the departure point or destination if the aircraft travels .....

Answer 47

west

Question 48

On the date of the spring equinox BOD and EOD will occur at .....

Answer 48

the same time for observers on the same meridian every location on earthe will experience the EOD and BOD at the same time!