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Guest tmetzinger

how about a back course approach?

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One thing that just popped into my head is the difference between the default MSFS 737 autopilot panel, which has a button for back course mode, and the NG autopilot, which doesn't (neither does the dreamfleet or the REAL NG).So my question is - how does one lock the autopilot to the back course of a localizer?Tim Metzinger

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Hmm not really sure, how about putting the ILS in your nav radio and setting the Course dial to RWY HDG - 180 then hitting just the LOC button?Don't normally fly the big boys on vectors so the little birdie logic is a bit off.Ray

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>Hmm not really sure, how about putting the ILS in your nav>radio and setting the Course dial to RWY HDG - 180 then>hitting just the LOC button?>>Don't normally fly the big boys on vectors so the little>birdie logic is a bit off.>>RayI did a test today trying to couple to the KPTK LOC BC 27L. No luck.Tim Metzinger

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Hummm, try setting the front course, the flight director should compare this with current heading, if this is more than 90* you should get back course. EDIT: I might add that I am not sure they even do this here (US)??[h5]Best Wishes,Randy J. Smith [h4]P M D G 7 3 7 NG[/h4]http://img.villagephotos.com/p/2003-8/196432/mineimage.jpg [h3] Realism on the horizon [h5]AMD XP 2200 |MUNCHKIN 512 DDR RAM |ECS[/b ][i] K7S5A MB[/i] |GF2 MX 32 MEG and still runs GOOD!|WIN XP PRO |MITSUBISHI DIAMOND PLUS 91 19"[/h5]

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Hi Tim,As far as I know, the LOC mode on the real 737NG allows front course tracking only. Although I wouldn't be surprised if a backcourse mode was an optional extra.As for the suggestion of turning the course selector through 180 degrees, this won't work. Having an instrument rating yourself you'll know that the course selector has no effect on the displayed course deviation when tuned to a localiser.So how do you fly a back course approach on autopilot? Use the same method as for NDB approaches: either LNAV or HDG SEL.In case you didn't already know, airliners fly non-precision approaches using a constant descent, unlike the light aircraft method of descending to MDA and then flying level to the MAP.Have fun!

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>Hi Tim,>>As far as I know, the LOC mode on the real 737NG allows front>course tracking only. Although I wouldn't be surprised if a>backcourse mode was an optional extra.I'd assume it must be, although I can see where airlines in first world countries wouldn't use it much, as nearly every airport they'd use has full ILS on all runways. I do know that the large jets (G-Vs and the like) that Daimler-Chrysler operates from PTK do have the ability to couple to the back course, as I have heard them tell ATC that the approach would be coupled.>As for the suggestion of turning the course selector through>180 degrees, this won't work. Having an instrument rating>yourself you'll know that the course selector has no effect on>the displayed course deviation when tuned to a localiser.It's only a help when flying by hand on an HSI - at least the presentation in APP mode on the NG sim does work so you can hand fly it.>So how do you fly a back course approach on autopilot? Use>the same method as for NDB approaches: either LNAV or HDG>SEL.That's how I salvaged my last attempt.>In case you didn't already know, airliners fly non-precision>approaches using a constant descent, unlike the light aircraft>method of descending to MDA and then flying level to the MAP.I've started to do much the same in some of the light aircraft I fly - since even a 172 nowadays has an autopilot that can maintain a set vertical speed. And with GPS WAAS in business, in the next couple years we'll see real VNAV capabilities in small planes too.-Tim Metzinger

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Very true about the HSI presentation working nicely; I was just thinking in terms of whether this would allow the A/P to couple.You must be flying some nice light aircraft out there Tim... most of them here in the UK have an INOP sticker over the A/P! :-roll

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Neil, just curious. What does the frozen mean in your sig?Best,

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The following text is from a 737 AOM I have which gives the procedure for flying BC Approaches.---BC LOCALIZER

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Is that a NG AOM Murf? That sounds a lot like Continental's AOM. I think that because the way it says "all B737" implying they have one than one in their fleet where Boeing does not use such a term in their AOMs...[h4]Best Wishes,Randy J. Smith [/4]P M D G 7 3 7 NG[/h4]http://img.villagephotos.com/p/2003-8/196432/mineimage.jpg [h3] Realism on the horizon AMD XP 2200 |MUNCHKIN 512 DDR RAM |ECS[/b ][i] K7S5A MB[/i] |GF2 MX 32 MEG and still runs GOOD!|WIN XP PRO |MITSUBISHI DIAMOND PLUS 91 19"[/h3]

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Hi Randy,Yes it covers the NG's (3's 5's & the 7's, 8's, 9's). Right about the airline too.

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Ok, I found that in that AOM but the others I have cannot locate that LOC BC. Maybe not looking good enough ;)[h4]Best Wishes,Randy J. Smith [/4]P M D G 7 3 7 NG[/h4]http://img.villagephotos.com/p/2003-8/196432/mineimage.jpg [h3] Realism on the horizon AMD XP 2200 |MUNCHKIN 512 DDR RAM |ECS[/b ][i] K7S5A MB[/i] |GF2 MX 32 MEG and still runs GOOD!|WIN XP PRO |MITSUBISHI DIAMOND PLUS 91 19"[/h3]

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Hi Robert,A frozen ATPL is a short-hand term to describe a multi CPL/IR with the theoretical exams passed to ATPL standard. It's the minimum required in JAA states to become a First Officer on multi-crew aircraft over 5700kg (with a relevant type rating of course). A full ATPL is needed to captain such an aircraft.When 1500 hours are obtained (with requirements on the type of hours), one can take a skill test and apply for the full ATPL; hence the term "unfreeze my ATPL". I believe the skill test is usually combined with the six monthly operator proficiency check (base check).

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In the real airplane we fly a BC Loc with Lnav. You could also use heading select if you want to work more. There is no BC Loc buttons on the real autopilot. Also, be sure to set the front couse and monitor raw data.

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>Very true about the HSI presentation working nicely; I was>just thinking in terms of whether this would allow the A/P to>couple.>>You must be flying some nice light aircraft out there Tim...>most of them here in the UK have an INOP sticker over the A/P!>:-roll I'm fortunate that when I rent aircraft I have a choice of 1998 or newer 172s and 182s, a pair of 2001 Archers, a pair of older Seminoles with brand new panels, and a 2001 Trinidad GT (SN 2000, it's was the demo airplane so it's been in all the magazines).Everything works and squawks get fixed quickly. Prices aren't too bad either. Although I must say it's weird to have a 172 with altitude preselect, and VS hold - the radio stack in the new cessna's are worth as much as the rest of the airplane.When I get paid to fly I'm usually flying a well equipped C208B - I love it, it's like flying a 182 on steroids (and the anti-ice is fabulous, it doesn't make me feel invincible but it's so nice to have some options when the icing starts.)-Tim MetzingerCommercial Pilot, Airplane Single and Multiengine Land, Instrument Airplane

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