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Guest Douglas Thompson

Peter - Beat you to it <g>! DP info

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To all,In an email, Peter asked (excellent question btw!) "..which dp are you suppose to fly if a runway has multiple standard instrument proc as is the case at Pearson?" (Toronto). Adding to Peter's initial question... "How do I know which DP to "plan" without knowing the departure rwy?". The answer(s) apply to all airports, not just Toronto/Pearson. Simplistic answer: Any one you want to; whichever is most appropriate dependant on your flight plan.Peter, there is no "should", and I'm not being "flip" when I say any one you wish. It all depends on what rwy you're assigned, what general direction your flight is etc. RCv4 gives you opportunity to be very creative. Here are some ideas...General Info - If your 1st 'planned' checkpoint is within 30m of the Dept field, RC will see that as a DP and not assign headings. If your DP has no checkpoints within 30m and you still want to be handled as a DP, use the "No Altitude Restr / Alt Restrictions" options on the Controller Info tab. Be sure you're headed towards your first checkpoint by 30m out. DP tolerance is 2m, enroute is 5m.You have options in using DPs. First, the Request Alternate Rwy option. Use this to "match-up" with a rwy-specific DP (if there's only one DP available for instance). The obvious downside is, you may be requesting a rwy that puts you in direct conflict with AI. How nice, you're taking off rwy 06, they're taking off rwy 24 :-( That'd make for an interesting afternoon, wouldn't it.Which DP to choose - I'd go with which ever DP has a checkpoint that is at least in the general direction of the flight (NE, SW, S etc), or a checkpoint that's on an airway you've filed etc. It all depends on the flight plan; iow, where you're going, in what direction. For my personal use Peter, it also depends on the distance of that first checkpoint regardless of direction. If it's too close, I'll not use it (rwy problems arise).CYYZ has six DPs (with very few checkpoint options). I see a few posting MALTN as a checkpoint. MALTN's tight, only 4m out. Unless I knew I was going to use rwy(s) 33, I'd not include MALTN. I'd look for an intersection (VOR, waypoint, whatever) further out that put me on a filed airway and take advantage of the DP options I wrote about above.Let's say the general direction of flight was SW. Knowing none of the CYYZ DPs offer a checkpoint to the SW, in the planning stage I'd include a checkpoint of some type, that was between 20m-40m out to the SW of the field, ensuring to use the RCv4 DP options if applicable. Planning a first checkpoint at this distance allows for use of any rwy, so that problem's now out of the picture.Do you see where I'm going with this Peter? Creativity is the answer, and there is no right/wrong answer. If anyone cares to add to this DP discussion, please do so. I welcome Peter to the RCv4 family (sure hope he shows up).

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but . . . :)Just a note that sometimes you have to use DPs with close in waypoints due to terrain obstacles. Sometimes you have to go in a direction not in line with your enroute FP to clear obstacles and merge with confined traffic patterns.I would guess this is more prevelant outside the US as we do not have too many large airports nestled within mountainous areas.I've seen the cockpit videos of departures and arrivals into/out of Cologne and Zurich in VFR conditions where if you do not follow the DP/STAR in fairly close range you could have instances of CFIT instances.In general, though, it is best to "go with the flow".I use frequently the PMDG 737 series which in its FMC allows entering DPs in its database. I generally enter the expected departure and fly under DP in RC if necessary but in the FP my first waypoint is 30 nm out. I have looked at the METAR for departure to get an idea of the expected runway (with AS6 or even after FS weather stabalizes from weather engine rights and AI is correct) listened to FS ATIS to get the active runway(s) AI is using. If on taxi clearance I find it necessary to change the FMC departure it does not take long to do that.It helps to have the IFR charts and/or a topo atlas of the area to get an idea of the terrain influences on departure.

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