ATC ignores my IFR FP and GPS approach procedure/transition

[aggrav8]

I create an IFR FP in Plan-G, ATC clears me, and off I go. I fire up my GPS and A/P, and ATC gives me a course and altitude. My FP wants to take me to three waypoints, then my destination - different than what ATC wants. I climb to the requested altitude but ATC says to expedite my turn - away from my first WP. I acknowledge but continue following my FP. But they're insistent. But I filed a FP and they cleared it! In real life, I assume that ATC would route me as filed. Is that right? I'm just a simmer, no real experience. How do I resolve this? Keep responding so ATC doesn't cancel my FP?

En route I decide to get fancy and select a GPS arrival proc to rwy 6 with a specific transition. ATC is still giving me directions, which I acknowledge but don't follow. The FP is taking me the way I want to go. Is this the best I can do, or is there a way to simulate this more closely?) At what point would I really load/activate an approach and transition on my GPS? After the third WP?

At present, between my final WP and the destination, I load/activate a GPS approach to rwy 6 and the same for a transition. I'm almost on final, but now the GPS wants to take me far to the north to several other WPs, and  look there... I've captured the localizer. Oh dear. Traffic is scattering. I've aggravated the northern hemisphere. How in God's name should I be doing this? I can't find the reading material I need.

Thanks and Best Regards, Gary

[tim arnot]

Main thing that comes to mind there is, does ATC think you're on the same leg of the flight that you do? Check the onboard GPS, you can usually set/reset the active leg through its menus. But sometimes the built-in ATC is just plain dumb. In the sim, you can always turn it off or change frequencies, and reactivate your plan later in the flight.

When would you activate an approach? When it's reasonable to do so. Don't necessarily expect to slavishly follow a flight plan - in real life, ATC will often cut a corner off for you, or clear you direct onto final. Quite often if you want to specifically fly a full approach (for training or practice or whatever), you have to explicitly ask for it.

[aggrav8]

Thank you Tim. I hoped there was a more straightforward way. FSX is very nice but it does have its shortcomings. I'm anxious to see what Microsoft's new FS2020 can do.

I've found several innovators but nothing as near to real life as I had hoped. Everyone knows to avoid responding to ATC. Plan-G is a super product. I donated quite a while ago. Think I'll do it again. I can't imagine the effort you've made. I like seeing where I am on the map. Best for me: I can use it build an FP and use the GPS to select/load a STAR and transition at a time that seems appropriate (still a guess).

Best Regards, Gary

[aggrav8]

I didn't get a notification when you replied to my post. I have the Notify box ticked. have I missed something?

[aggrav8]

I don't think ATC is aware of my FP, much less which leg. Onboard GPS is directing me precisely along the path of my plan. ATC blindly keeps giving me courses and altitudes of it's own, unaware of intersections, as if all it knows is my destination airport. The onboard GPS matches the Plan-G map and my view out the window so I think I'm right where I should be.

I agree that in this case ATC is dumb. But I haven't attempted this before so I'm not a bright light either. For example, I have no idea when it's reasonable to activate an approach. Just before the first WP (same as intersection?) in the transition? (I think the en route portion ends when I reach the first WP of the transition.) I thought the objective is - file a plan, load it in my GPS, and AP will follow the route, all the while with ATC prompting me to turn where my plan already says I want to turn. I think I lack the knowledge of how all IFR traffic follows the rules. Haven't seen a tutorial about that yet. I have a young friend who recently did his first cross country, and his father flies an EMB190. I'll exploit that resource next.

[tim arnot]

I don't have an instrument rating, so any advice I have is worth about half the price you paid for it.

An ILS extends about 20 miles from a runway (Plan-G draws 20 mile long ILS feathers). Most approach procedures try to put you on final generally somewhere between 10 and 20 miles out (the bigger & busier the airport, the further out it tends to be). As a rule of thumb, I'd suggest that once you've passed the final enroute waypoint, you can activate the approach. But the cardinal rule of planning is: the shortest distance between two points is a straight line. Don't dogleg unless you have to, so sometimes you might like to skip that final waypoint. Which is fine. Unless ATC tells you otherwise (if you're under ATC control, you must always go where ATC tells you)

Descent planning is easier. The approach gives you the altitudes to be at every step along the way (shown on the approach plates, and in the Plan-G plan grid). You know your cruise altitude, speed, and the plane's rate of descent, so the top of descent  can be calculated. (easy approximation: 3 X vertical distance to drop in feet / 1000 = distance in nautical miles. So from 20,000 feet: 20 x 3 = 60 miles. That assumes a 3-degree descent rate, and doesn't take into account any head/tailwind) You can also set the desired altitude & descent rate in Plan-G and use the altitude banana ;)

As for the forum notification email, this is free forum software, so I guess it's worth about what I paid for it!