More IFR help
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More IFR help
Hi people
I need some help with regards to this question - i have looked in my text book and i am getting even more confused
.
How to determine you position in relation to the required track TO and FROM an NDB.
cheers
I need some help with regards to this question - i have looked in my text book and i am getting even more confused
.How to determine you position in relation to the required track TO and FROM an NDB.
- Using the RMI, RBI & the rotatable card ADF.
cheers
Using an RMI:
Think of the RMI's face as a space eye view of the earth's surface. When you do so, the centre of the RMI represents the NDB (or VOR, if the RMI can be selected to display VOR information). The aircraft would be located on the tail of the needle, and oriented as you look at the instrument so that it is always facing up the instrument panel
BFS >--____^_____ ---------O--------------------> BTS
................_|_
ignore the dots -they're to adjust spacing
Bearing FROM Station is the number aligned with the TAIL of the needle.
Bearing TO Station is the number aligned with the HEAD of the needle.
Aircraft heading is under the index at the top of the instrument, as usual
Rotatable ADF card (poor man's RMI)
Rotate the card so that aircraft headng is under the top index. It now looks just like an RMI.
Fixed card:
Method 1 (even poorer man's RMI):
Align your pen, pencil or finger to the ADF needle, with the nib or point to head of needle. Holding that alignment, move your pen over to the DI/HSI. The alignment of your pen with the ADF needle, and over the DI, gives the same information as if the two were an RMI.
Method 2 (mental RMI):
Observe where the the tail &/or head of the ADF needle is w.r.t. the top, bottom or abeam point(s) by noting the degree marks around the circumference of the ADF. On the DI count the same number of degree marks from the equivalent position. That point represents where the tail or head (respectively) of the needle would be if the DI was an RMI.
Method 3 (mentally insane):
Use the formula BTS=HDG+ADF. Remember to subtract 360 deg if the number goes over 360. Subtract 180 deg to find BFS. Don't forget you're still supposed to fly the aeroplane while doing all this maths.
Think of the RMI's face as a space eye view of the earth's surface. When you do so, the centre of the RMI represents the NDB (or VOR, if the RMI can be selected to display VOR information). The aircraft would be located on the tail of the needle, and oriented as you look at the instrument so that it is always facing up the instrument panel
BFS >--____^_____ ---------O--------------------> BTS
................_|_
ignore the dots -they're to adjust spacing
Bearing FROM Station is the number aligned with the TAIL of the needle.
Bearing TO Station is the number aligned with the HEAD of the needle.
Aircraft heading is under the index at the top of the instrument, as usual
Rotatable ADF card (poor man's RMI)
Rotate the card so that aircraft headng is under the top index. It now looks just like an RMI.
Fixed card:
Method 1 (even poorer man's RMI):
Align your pen, pencil or finger to the ADF needle, with the nib or point to head of needle. Holding that alignment, move your pen over to the DI/HSI. The alignment of your pen with the ADF needle, and over the DI, gives the same information as if the two were an RMI.
Method 2 (mental RMI):
Observe where the the tail &/or head of the ADF needle is w.r.t. the top, bottom or abeam point(s) by noting the degree marks around the circumference of the ADF. On the DI count the same number of degree marks from the equivalent position. That point represents where the tail or head (respectively) of the needle would be if the DI was an RMI.
Method 3 (mentally insane):
Use the formula BTS=HDG+ADF. Remember to subtract 360 deg if the number goes over 360. Subtract 180 deg to find BFS. Don't forget you're still supposed to fly the aeroplane while doing all this maths.
Last edited by Tinstaafl; 9th Mar 2012 at 04:14.
I havnt started IFR flying yet so how would this be of use to me?
It's as simple as it gets!
