A couple of wee problems with general nav

[Jinkster]

Thanks in advance for the help.

ref.

7) You are flying 090C heading. deviation is 2W and variation is 12E. Your TAS is 160kts. You are flying the 070 radial outbound from a VOR and you have gone 14nm in 6mins. What is the W/V?

Answer = 158T/51

54) An aircraft starts at position 0410S 17822W and heads true north for 2950nm, then turns 90deg left and maintains a rhumb line track for 314km. what is the final position?

Answer = 4500N17738E

55) You are heading 080T when you get a range and bearing fix from your AWR on a headland at 185nm 30deg left of the nose. What true bearing do you plot on the chart?

Answer = 230 from the headland using the aircrafts meridian


Thanks for the help.

[M.85]

Jinkster..

I reckon you go through a long distance course to have so many questions..
First question..use the weezzzzzwheel.
Sec:learn how to draw..
Third:see the second.
I doubt people can help you out here..its too technical..you may want to go to the instructor/student forum ...you may get guys who do study Gen Nav at the moment..
Have fun!
M.85

if you really really need to understand these questions..ill find out how to do them tonight..i remember question 54 from last year!

[Field In Sight]

I'll have a go at the first one.

1. First convert everything to the same unit. i.e. degrees TRUE and KNOTS.

Heading - 090C - Deviation = 088M - Variation = 100T
TAS = 160 KTS.

Track - 070M - Variation = 82T
Ground Spd - 14NM / 6 X 60 = 140 KTS

Now you know 4 variables out of the 6 in the triangle of velocities you can work out the other 2 using yourtrusty CRP-5 or use this link

http://www.csgnetwork.com/e6bcalc.html

And Oila,

The answer pops out.

FIS.

PS. I found it a lot easier if I drew out roughly the triangle of velocities on a piece of paper before I even started calculating the wind. If the picture looks the same on the CRP-5 then you are probably right.

PPS. You can always work backwards and plug in the available answers one at a time. To get the given variables.

PPS M85 is quite correct in saying, wait for the brushup course, you will get plenty of practice.

[Northern Highflyer]

Q7

Calculate true heading from 090C = 100T
TAS is given as 160Kt
Heading (070 radial) will be 082T
Groundspeed = 140Kt (14 in 6 minutes)

Use the whizz wheel to get W/V

Q54

2950 NM = 49.1 degrees (divide by 60)
49.1 degrees added onto 0410S gives you 45 North
From here use departure to find out how far East you have travelled to get the change of longitude. Remember you are crossing the antemeridian, hence the change from West to East.
You have to convert from KM to NM first.
314 KM = 170 NM
170 NM at 45N = 4 degrees longitude travelled.


Q55

080T less 30 (30 left of nose) = 050T QUJ
Therefore the bearing to your position is the reciprocal = 230T

Hope that helps

NH

[Jinkster]

Thanks for all the help - sorted now

Jinkster

[M.85]

just a little add on to Northern Flyer:to get 4 degrees in change of longitude ,you have to use the "departure" formula.
Dep(NM):ChlongXcosLat.
Therefore:Chlong=170/cos45=240NM.
Since 1 degree=60NM ->Change of Longitude is 4 Degrees.

TATA,

M.85

[Jinkster]

M85,

Thanks very much

Jinkster