Hi everyone,

just doing my final bits of study for my upcoming IREX exam. I've just stumbled upon a few questions that I need clarified please.

1. You departed Parkes for Katoomba and are tracking via designated route W595 allowing for 7 degrees of left drift. if your ADF is tuned to Bathurst, the ADF indication which would show that you were abeam Bathurst is -

*to make things easier the FPT of 098 magnetic from Parkes to KADOM (no longer is Katoomba I think, but they use the same W595). The answer is set as 263 degrees R and would only make sense if we had RIGHT drift. My answer was 277 degrees R, which makes sense to me as Bathurst is on our left and if we have left drift it means my heading will be towards the right of the FPT meaning 270(abeam) + 7(duetodrift) degrees = 277 degrees R.

2. Assuming that no OPRs are imposed by either weather or runway lighting, the minimum radio navigation aid requirement for an aerodrome to be suitable as an alternate for a NGT VFR air transport flight is -

*the answer was "one VOR or one NDB or 1 GPS TSO 129 or higher is required" which makes sense but not completely. As in part 91 MOS it explicitly explains "without limiting the requirements under subsection (5) and (6)" which were that the navigation equipment required would be such that if a failure were to happen it has a back up. Therefore I chose "two different aids are required" as an airtransport flight you need two attempts at an approach. However going with the answer Bobtait specifies it only gives the flight one attempt! That is if it fails of course.

I would greatly appreciate anyone's help!

Kind regards,

James

If you are flying with left drift and the station is on your left, the situation will be like this.



The ADF will read 263°R when you are abeam. The question has been changed to reflect that.

The requirement for two aids applies only to an IFR flight. Night VFR is not an IFR flight.

1. Ahh I had the diagram correct but completely misjudged the way the ADF would display. I was very upset that I got this seemingly 'easy' question wrong as it's the ones I'm best at and enjoy. Thanks for that Mr Tait.

2. I see, however does the sentence "without limiting the requirements under subsection (5) and (6)" - Part135MOS11.09(2). Doesn't this mean that the aircraft must be able to survive the failure of a navigation aid and still do an approach too?