March 12, 201214 yr First, unrelated to my question: Ryan, awesome tutorial. I'll admit to not being a guy who does LOWI very often, but a great tutorial with a few tricks that I didn't know.So, here's a question I had (spurred by the fix work done in the tutorial): is thre a way to program a specific vector/heading into the FMC and have the A/P follow it in LNAV mode? For example, say you're on a STAR and you need to be vectored to the IAP. ATC says: "After [FIX], fly heading XXX." Now, of course you can just put the heading in the window and hit heading select when you get to FIX, but it dawns on me there has to be a way to draw a line on a heading that the LNAV will follow.Thoughts? Thanks. Doug Orvis PP-ASEL-IA (USA), Based at KHEF Picture courtesy of Kyle Rodgers
March 12, 201214 yr Commercial Member If you're flying offline, you could always downselect the last fix, and use a PBD waypoint. If my last fix is DARIC, I can downselect DARIC using the LSKs. From there, just add a /190/20 (where it's /BBB/DD; B for bearing, D for distance).The reason I say offline is that using that method will make you track that heading, meaning it will correct for wind. If ATC assigns a heading, they're talking about bearings, not tracks. Bearings do not account for wind, and ATC assigns headings to compensate for the wind.If the wind is strong and we need you to track 190, we may say "fly heading 200." If you use the method of PBD, you will actually fly further west than I need, which could cause probs. Kyle Rodgers
March 12, 201214 yr Flying into Seoul, they'd give us a clearance like that all the time. "Depart Anyang heading 250." We'd do just like Kyle suggested - just make a fix off in that direction. At the same time, we'd "pre-select" 250 on the MCP, but leave it in LNAV. Once the plane hits the fix and starts its turn, then you just hit HDG SEL.If a STAR or SID is already coded with a vector, then you can leave it in LNAV and it will handle the heading for you. Matt Cee
March 12, 201214 yr Commercial Member If a STAR or SID is already coded with a vector, then you can leave it in LNAV and it will handle the heading for you.Yeah, I forgot to mention that part.Additionally (to make it more complicated, right?), certain STARS will specify TRACK HEADING 000, meaning you would use what you mentioned earlier.As an example, the SHNON2 into IAD uses that phraseology: http://155.178.201.160/d-tpp/1203/05100SHNON.PDFDown at the bottom in the narrative, it says "From ELISN via 011 track to MATTC."The FMC will have this already set in there, but if it didn't, you could use the above procedure. Kyle Rodgers
March 12, 201214 yr Author Thanks guys. I actually get this kind of instruction in my bugsmasher in real life all the time. (For Kyle's amusement, my most common one is: "After MULRR, Fly Heading 190") But both of you are describing what I have in mind. This is from memory, but here how this got me thinking about using the FMC like this: This morning, I was flying the MOXEE6 arrival to KPDX, which ends just south of the airport and has arrows going 280 and 100. Today, it would require me to then fly a 280 heading to go downwind for the 10 runways. In theory I could have done it for a specific distance and made a fix, that I got... But I was imagining a vector for sequencing and then the turn, (I don't fly online for a host of reasons.) so, I essentially wanted an endless line. I've seen the endless vectors in the STARs before, ( I think PHOG had one.) So, using my IRL example above, if I had MULRR in the FMC, I would type in MULRR/190, and then insert it below MULRR, it would create an endless line heading southish out of MULRR. (Kyle: essentially a downwind for 1L/C/R at KIAD, although that's how they get me to KHEF.) I'll have to try that. Doug Orvis PP-ASEL-IA (USA), Based at KHEF Picture courtesy of Kyle Rodgers
March 12, 201214 yr Commercial Member Thanks guys. I actually get this kind of instruction in my bugsmasher in real life all the time. (For Kyle's amusement, my most common one is: "After MULRR, Fly Heading 190")[...]So, using my IRL example above, if I had MULRR in the FMC, I would type in MULRR/190, and then insert it below MULRR, it would create an endless line heading southish out of MULRR. (Kyle: essentially a downwind for 1L/C/R at KIAD, although that's how they get me to KHEF.) I'll have to try that.I think in order to have the endless vector, it needs to be coded in, and not set in by the pilot. You could, however, just go in and set it to something absurdly long (50-100nm will suffice - too long and you'll get fuel warnings). I could be wrong on that. If I'm not wrong, you could just throw in MULRR/190/50 and be okay. In your case, however, it'd be better to file/fly the HYPER in the NGX, but I'm guessing you were just using it as an example.In on the DELRO in the bugsmasher? I suspect you can't file/fly the HYPER, but in your situation, in the end, they're really just trying to get you to mirror the HYPER arrivals, so you could get away with setting a track of 190 in that case (the HYPER arrivals track 196 to SIGBE -> 189 to HUSEL ->191 to YACKK -> 190 until further advised).I'm not saying always assume you know what the controller wants, but if you look at another arrival that's a more precise/specific version of the one you're flying, you could help them out by emulating it to the best of your ability. They'll still put you on a vector, if you're on the DELRO, but they essentially just want you to track down a narrow corridor between IAD and DCA and not bust airspace. If you manage to do that on your own, that's just less they have to tell you to do. Kyle Rodgers
March 12, 201214 yr Author Yes, that was just an example. From this morning it would be FIX/110/XX in your example. As for KIAD, I think there's a question about whether HYPER crosses into the no fly zone (plus I'm too low to use it). Ditto the transition at MULRR if P-40 is enlarged. That's kind of an issue for us Part 61 guys who don't want to get blown into pieces. But, yeah, its ostensibly, it's the same route. I get pushed down from cruise levels starting about LNP and there's a Victor airway that heads toward MULRR. That's what I'm on. If I file for a procedure, I don't get it. Also, some guys who run that sector aren't cool about east side transitions, which is no bueno for those of use going the KHEF. I find I only get a good route if a I file through AML (which I have, never, ever gotten), which is an transition to the GPS approach to the short runway. Doug Orvis PP-ASEL-IA (USA), Based at KHEF Picture courtesy of Kyle Rodgers
Create an account or sign in to comment