Final

Question 1

What is a Nm?

Answer 1

Length of arc of a GC 1min from centre of earth at 47*42’N

Technically larger at equator than at poles

Question 2

What is 1Nm in m?

Answer 2

Always use 6076m

Question 3

How to convert arc of longitude into time?

Answer 3

360=24hr
15=1hr
1*=4min
Change seconds into scale by min/60

Question 4

Compare LMT with LST

Answer 4

LMT is local mean time and is the time since the transit of the sun over the anti meridian of the observer. Is a specific time to the position on a longitude.
LST is a zone time used for practical purposes.

Question 5

How to calculate zone time?

Answer 5

A meridian +/-7.5* is a zone.
Divide longitude by 15, if remainder after decimal is greater than 1/2 round number up, if below round number down. This number is your zone number and add/subtract from UTC.

Question 6

What map properties are ideal?

Which are unachievable?

Answer 6

Scale constant and correct (1)
Rhumb lines great circles are straight (3)
Angles and bearings the same as earth (2)
Shapes and areas are correctly represented (can’t be over large area) (2)
Cordinates readily extracted
Adjacent sheets fit
World wide coverage.

Question 7

What is orthomorphism?

Answer 7

Bearing is correctly represented. So for angles to be correct, scale must be adjusted. So around a point scale is constant, may vary across a map.
Meridians and latitudes must intersect at 90*

Question 8

What is homolography?

Answer 8

Areas are correctly represented. Scale contraction in one is compensated by expansion in the other.

Question 9

What is the parallel of origin?

Answer 9

Latitude equal to the semi apex angle.

Question 10

What is a standard parallel?

Answer 10

Cone touches the scaled globe. Scale is correct at these points. Contracts between and expands outside.

Question 11

How to calculate departure?

Answer 11

Cos lat x 60 x chlong

Question 12

What are the basic properties of a Mercator chart?

Disadvantages?

Answer 12

Scale at equator is correct, expands at sec lat. Is not equal area and large shapes distorted and shapes away from equator distorted. Bearings correctly represented so is orthomorphic.
Not used behind 60* as SF exceeds 2.

Disadvantages include radio bearings are GC, scale varies and no polar.

Question 13

How are rhumb and great circles in a lamberts?

Answer 13

GC concave to PoO but approximate straight lines

RL concave to pole of projection

Question 14

How to calculate convergence?

Answer 14

Sin lat x chlong

Question 15

Remember the following GPS things…

Answer 15

24 satellites in 6 orbitals planes angled at 55* to equator in 12hr semi synchronous orbits.
Ephermis data gives current positions of satellites in orbit
Almanac provides orbital data to predict satellites in view.
3 segments include control, ground and space.

Question 16

How many satellites required for RAIM?

Answer 16

4 to achieve a unambiguous 3D fix in air.
5 required for fault detection (RAIM).
6 required for exclusion.

Question 17

High vs low PDOP?

Answer 17

Low: satellites spaced so good
High: opposite

Question 18

GPS errors?

Answer 18

Ephemeris, mulitpath, ionospheric, tropospheric, receiver, interference, radio noise.
Ionospheric worst.

Question 19

Max payload calculations?

Answer 19

Is the minimum of the following,
BRW- (NOW+FOB)=MCTOW - (NOW+FOB)
MLW - (NOW+RES)
MZFW-NOW
If limited by ZFW, fuel can be carried to the next highest payload value.

Question 20

MTOW calculations?

Answer 20

Least of following
MTOW
MLW+ FX B
MZFW + FOB

Question 21

How to calculate RoC?

Answer 21

RoC (ft/min)= % x 1.013 x gs

Question 22

How to calculate specific air/ground range? And SFC

Answer 22

SGR = GS/GFC
SAR= TAS/GFC is the nm/unit fuel
SFC = GFC/TAS

Question 23

Go away and practice S4 things

Answer 23

Go!

Question 24

Mach equation

Answer 24

M x 38.94 SQRT(K) = TAA