"Randy at Home" wrote in message . cable.rogers.com...
"John Harlow" wrote in message
...
|
| Here is a fantastic question. No prizes for getting the right answer
| (with explaination) but anyone fancy a go?
|
| Given the following:
| Ground speed 90kts
| aircraft altitute 6000ft
| VOR transmitter at mean sea level
| Tan 40° = 0.839
| assume 6000ft = 1nm
|
| Theoretically, for approximately how many seconds would you expect the
| morse identifier to be inaudible within the cone of silence if the
| aircraft is tracking directly TO the VOR followed by its reciprical
| directly away FROM the VOR?
|
| A - 7 seconds
| B - 20 seconds
| C - 67 seconds
| D - 100 seconds
|
| None of the above. The "cone of slience" causes morse and any other
| identifiers to become inaudible anytime the user is wearing one, as
| demonstrated on several "Get Smart" episodes.

Would you believe, A...?
Uh,.. how about, B...?
Missed it by ---||--- that much.

The cigar goes to Bill for answer A and the explaination too. The
answer book says the following:

VOR signal propagation is omni directional in the horizontal plane but
confined to an angle of 40 degrees to the vertical which creates an
area in which there is no signal propagation. This area is known as
the Cone of Confusion or Cone of Silence.
However, the AM morse ident signal is propagated omni directionally in
both the horizontal and vertical plane and therefore audible within
the cone of silence.
There are 4 morse idents every 30 seconds. Three consecutive VOR
idents are transmitted at 7,5 second intervals followed 7,5 seconds
later by a DME morse ident if a DME is co-located with the VOR.

The nearest correct answer is A.

I have not come across a question like this in the IR knowledge test,
is it something an examiner would ask as part of the oral?

In the UK you get this in the test but examiners are not likely to ask
sucha question in the oral.