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1
Q
  1. What happens to the ETP if you have a headwind component on the outbound leg?
A

a. The ETP will move towards the aerodrome of destination.
The position of the ETP will always move into wind, away from the mid point.

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2
Q
  1. Definition of ETP
A

a. The ETP is that point along track which it will take the same time to continue to the destination, or return to the departure aerodrome.
ETP is a time consideration

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3
Q
  1. ETP Formula
A

x=DH/(O+H)
X= Distance from departure aerodrome to ETP
D= Distance from A-B
H= The groundspeed home from ETP (TAS corrected for wind)
O= The groundspeed onwards from ETP to B (TAS corrected for wind)

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4
Q
  1. Definition of PNR
A

a. Beyond the PNR there is insufficient fuel to return to the departure aerodrome with all the regulatory fuel reserves intact.
The PNR will always lie at or beyond the ETP between two aerodromes
PNR is a fuel consideration

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5
Q
  1. PNR Formula
A

D=EOH/(O+H)
D= Distance to PNR
O= The groundspeed out to the PNR
H= The groundspeed home from the PNR
T= Time out to the PNR
E= Aircrafts safe endurance (i.e. allowing for reserves) in hours. Note, when calculating safe endurance time must be in decimals (6 minutes = 0.1).

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6
Q
  1. What happens to the PNR with changes in wind?
A

a. In nil-wind the PNR will be at a distance from the departure aerodrome equal to half the safe endurance.
Any wind component, head or tailwind, will bring the PNR closer to the departure point in distance.

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7
Q
  1. What fuel is included in the PNR safe endurance?
A

a. Total fuel less unusable, reserves, holding, instrument approaches, possible diversions or any other contingences that may apply.

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8
Q
  1. You are early at ETP, which way does it move.
A

a. The wind is less than forecast, the ETP moves away from aerodrome of destination.

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9
Q
  1. You are 10 minutes ahead on your flight plan going between Wellington and the Chatham’s. What does this do to the position of your ETP?
A

a. The actual headwind is less that the forecast. The ETP moves away from the aerodrome of destination.

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10
Q
  1. Taking off Wellington to Chatham’s. You are behind on your ETA. What is this going to do to your ETP
A

a. Wind is stronger than what was forecast, ETP moves towards the destination.

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11
Q
  1. A question with take-off time in local and flight time, what is landing time in a different time zone
A

a. Calculate the degrees difference of longitude.
360/24=15, therefore ever 15 degrees of travel = 1 hour time difference.
(140 degrees /15 = 9.3 hours difference = 3 hours 18 minutes)
Traveling east is behind time, so subtract time.
Traveling west is ahead of time, so add time.

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12
Q
  1. Simple time conversions ie leave xx at 0615 Local on Saturday. Land XX at xx Local. Given UTC at each location. What is flight time?
A
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13
Q
  1. Formula for 1 on 60 rule
A

60/Distance gone=Track Error/Distance off

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14
Q
  1. 1:100,000 chart scale to NM
A

(chart length)/(earth ditance)=Scale

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15
Q
  1. What do straight lines represent on a Lambert’s chart?
A

a. Great circle
(Mrs Convex Pole= Mercator chart rhumb lines are straight, and great circles are convex to the nearest pole. Lambert charts are opposite).

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16
Q
  1. Flying the most direct route on a Mercator chart what is it and what does it look like?
A

a. Curve Convex to the pole (GC track)
(Mrs Convex Pole= Mercator chart rhumb lines are straight, and great circles are convex to the nearest pole. Lambert charts are opposite).

17
Q
  1. Great Circle
A

a. A circle drawn on the face of the earth whose radius is the earth. Its plane passes through the centre of the earth. It is the shortest distance between two places.

18
Q
  1. Small Circle
A

a. Any circle drawn on the earth whose radius is not the earth. Its plane does not pass through the centre of the earth.

19
Q
  1. Rhumb Line
A

a. A line drawn on the centre of the earth which cuts each meridian at the same angle.

20
Q
  1. Parallels of latitude
A

a. Small circles joining points of equal latitude – except equator, which is a great circle
All are rhumb lines
Lie east to west

21
Q
  1. Meridians of longitude
A

a. Semi-great circles passing thru the poles

22
Q
  1. Prime Meridian
A

a. A semi-great circle passing through the poles and also Greenwich. Known as the Greenwich meridian. It defines a longitude of zero degrees.
0000UTC is said to exist when the sun is directly over head the anti meridian (180)

23
Q
  1. Isogonal
A

a. Line joining points of equal variation

24
Q
  1. Nautical mile
A

a. Distance on the surface of the earth which subtends an angle of one minute of arc at the centre of the earth
6080 ft
One degree ofchange of latitude along a meridian represents a distance of 60nm (60min of arc)

25
Q

What is the departure formula, and when is it used?

A

a. Necessary due to the fact that 1 degree of longitude is only equal to 60nm at the equator. Any deviation from the equator needs reference to the departure formula.
Distance (nm) = change of long x cos lat

26
Q

What is earth convergency and its formula?

A

a. The angle of inclination between two meridians at any given latitude
b. Earth convergency = change in long x sin mean lat

27
Q
  1. Rotation of Earth
A

a. 900kts at equator
900 x cos lat = speed at a given latitude

28
Q
  1. Mercator projection
A

a. Cylindrical projection
All meridians appear as straight lines with parallel spacing
All parallels are straight lines with the distance between them increasing with increase in latitude
Poles are unable to be projected
Lat and long intersect at right angles
A Rhumb line will appear as a straight line
A great circle will appear as a curved line convex to the nearest pole

29
Q
  1. Lambert Projection
A

This utilizes a conical projection with the apex of the cone directly above the pole
Meridians appear as straight lines converging towards the pole
Parallels appear as straight lines with the distance between them being constant
Lats and Longs intersect at right angles
Rhumb lines appear as curved lines convex to the nearest pole
Great circles appear as straight lines

30
Q
  1. Conversion Angle
A

a. This is the angle between the great circle track between two points and the rhumb line track between two points. It is equal to half earth convergency.
Conversion angle = 0.5 change in long x sin mean lat

31
Q
  1. Orthomorphism
A

a. All chart used for nav must have these two qualities.
i. The scale on the chart must be correct to the scale nearby (equal scale expansion)
ii. Parallels and meridians must cross at right angles.

32
Q
  1. Time to Arc
A

a. 1 of arc = 4 min.
15’ of arc = 1 min.
1’ of arc = 4 sec.

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