I was just about to ask the same question as Aviatordan..

Hi Bob,

Here is some pages directly from the US Department of Transportation FAA Pilots Handbook of Aeronautical Knowledge (FAA-H-8083-25A).

I have underlined the key points I learnt from and included a copy of the US Flight Planning Guide. In summary they appear to suggest that Magnetic headings are not accurate enough on longer, faster, or more magnetically varying flights, and therefore should be calculated in true, as well as headings.

I have also included a copy of front and back of the E6B that I use, which now makes perfect sense. In terms of approach charts for airports it makes sense to use magnetic due to the proximity of the airport, but on the cross country flights it appears that is where True Course is more relevant. See if you can see where I am coming from, I would be really interested in your educated opinion, on the forum or PM.

It relates to where I take the flight component as well, as I may well do the CPL flight rating at Flight Safety in the US, or Oxford or Brisol if I go JAA, but I'm not sure yet. I just want the best foundation I can get my hands on, and I've seen a few Uni's try to have a go as well

Hi Bob,

Back when I first asked you I also (out of sheer desperation that was doing my head in) asked the question of a 74 year old Veteran Pilot ex Major Global Airlines (lastly Qantas) with 33,000 hours, 50+ Type Ratings and 5 ATP(L) of which I have personally sighted, and this is what he said to me (I only just got the email): (I'll call him to Clarify, but it tends to indicate the necessity of True Course on planning LONGER flights: (does this make any more sense to what I was suggesting or am I just being Anal Retentive (Go on - just be honest It's just I struggled with Nav to start with and having worked with Computers and Data Processing equipment for 20 odd years in Enterprise systems, I have an interest in getting the underpinning fundamentals spot on.

Here goes:

Brook.

I could carry on With some paragraphs to answer your question and still not
be exactly sure that I have answered it to your satisfaction.

However, a brief summary is that a track measured on a WAC chart will be in
T and needs variation applied to be M. Also, area winds are T but
Terminal winds are M as are tracts on terminal charts. I won't elaborate
further now but give a call if you have any difficulty. Once you get it
right you won't have any further problems.

All the best.

JG

That's a good point for long flights in high latitudes. I can see that it might be an advantage to have the true track available when there is going to be large and rapid changes in magnetic variation enroute. It's even possible on a long flight at high latitudes to have variation changes from East to West variation.

Thank goodness you're in Australia now - you can relax at bit!!

Bob

Hey Brook,

I may not be able to answer your question but I'll try to share some insight =). I'm not sure where you are, geographically, so forgive me if I spout some information you already know!

In my experience, albeit limited, I've found it's always best to do things in magnetic. And I guess the point I have to stress is that I've only done flying training in Australia, so I can't say anything for other countries and their magnetic variations.

When I plan a flight I do everything in magnetic, just because it makes it easier in flight. I use the E6B to find wind correction angles etc, all in magnetic. The E6B says to do it in true, however, I just pretend that in stead of the word "true" it says magnetic. That was something that really confused me to start off with.

As far as flying on the true bearing, that really depends where you are (in Aus). I mean, where I am, on the East Coast, the magnetic variation is 12° E so it would be silly to use the true because you'd be pretty far off your destination (depending on the length of flight). Around here, I use the 12° E for flights of any length, I mean it's 70nm West before you hit the next isogonal and even then it only changes by 1/2 degree.
However, just east of Perth, the variation gets to 0° so around that area true = magnetic, so it's perfectly fine to use true.

I guess it just depends on where you are!

I hope that can be of some help =).

Thanks Bob - at least i'm not loosing it

Guess since we're not doing a huge amount of antartic flying, it wont give us the same challenges as the yanks...

Thanks Aviatordan,

Yeah it sounds like you need a faster aircraft too No seriously appreciate the advice, the bit about "it's 70nm West before you hit the next isogonal and even then it only changes by 1/2 degree" is really relevent".

I fly on both sides, but for now am based on Perth, I get over east about every three months to do some flying.

Where abouts are you over east?

Brook

I do need a faster aircraft! The TAS on the 172 I fly (or even the Arrow) is not anywhere near fast enough! I wish someone would throw a Hornet my way...

I live on the Central Coast, about an hour and a half north of Sydney (by car). Who do you fly for that lets you go from coast to coast? Get me a job with them? =P

I'm glad I could help, mate =].

I've got my AGK exam tomorrow so Ive been studying like mad over the last few days, hence the lag in replying!

Have a good one!!!

Hi AviatorDan

Yes that TAS can get you down sometimes. I have my own little outfit on the east coast, but same boat as you, kicking the CPL exams over to make way for ATPL.

Good luck with AGK, make sure you check out my tips in the AGK forum I left some stuff I dumped right outside the exam booth, exam type questions..if you are still up reading this, good luck tomorrow!

Brook

Thanks, Brook =). I did end up reading your tips and they helped a great deal! But yeah, I ended up passing, which was a massive relief. Now onto MET!