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Guest esperienza

correct missed approach procedure...

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Hi to the big community, I was trying a few missed approaches today and found out I don't know the correct procedure to follow once I'm at 200 feet or more from treshold and decide to call for a missed approach.This is what I did:-Before decision height I inserted 4000 in the mcp which was my altitude restriction for a hold on the last missed approach waypoint-At 200 feet or more I engaged TOGA thrust and the response from the airplane was very nice._Then I thought the best thing to do was to engage vnav, then lnav and let the autopilot take care of the rest by giuding me to the hold.Now, when I engaged vnav a message in the fmc popped out telling me to check mcp altitude...I consequently tried, as a last minute attempt to reset the fmc, to insert a new altitude on the rte page but just couldn't get the plane back on clb thrust setting anymore to climb to 4000 feet altitude which was previously inserted in mcp as reference for the hold...remember?Is there a tutorial out there that goes through a missed approach procedure?Is this function implemented in the fmc?If yes, what am I doing wrong?Thank you guys for your time,David

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Hey,I would also love to know how to correctly do a missed approach. I fly with the 737 a whole lot, and I can't tell you how many times I've been on final and had an AI aircraft take its sweet time getting off the runway, forcing me to go around. If I weren't in Baghdad, I'd buy RadarContact and that might hopefully help with the ATC issues, but I'm too impatient to wait for it to get here through the mail...I've set up the missed approach on the FMC, (I think) but never gotten the FMC to fly the procedure.Thanks in advance that any smart person can give us...--------------------------------Sean McCaffertyP4 2.41024 MB DDRFX5600

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>Hey,>>I would also love to know how to correctly do a missed>approach. I fly with the 737 a whole lot, and I can't tell>you how many times I've been on final and had an AI aircraft>take its sweet time getting off the runway, forcing me to go>around. If I weren't in Baghdad, I'd buy RadarContact and>that might hopefully help with the ATC issues, but I'm too>impatient to wait for it to get here through the mail...>>I've set up the missed approach on the FMC, (I think) but>never gotten the FMC to fly the procedure.>>Thanks in advance that any smart person can give us...>-------------------------------->Sean McCafferty>P4 2.4>1024 MB DDR>FX5600In general, a missed approach (if programmed in the FMC) is flown in LNAV for lateral control, and LVL CHG or VS/SPD mode for vertical control.There are some weaknesses in the sim in terms of the FMC. The FMC works in phases - climb, cruise, descent, IN THAT ORDER, and I don't think the logic is in place yet to make it go back to a climb mode. That's why things like alternate airports don't work yet.Next time you go missed from an ILS, try this:Set the missed approach altitude in the MCP altitude window after you intercept the glideslope.at minimums, hit TOGA and begin to clean up the airplane. Then hit LNAV and LVL CHG and if you've cleared all the discos from the FMC missed procedure you should fly the procedure correctly, but you'll still have to manage any altitude changes using the MCP.My tutorial will have a missed approach or two in it. I'm writing that part today.

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Timothy,You will never want to use V/S mode for a go-around. Never ever. It's not speed protected.The FMC is not that important in the go-around procedure. Basically if it displays the missed approach fix correctly, and knows how to follow the course from the intended runway to that fix, and the dynamical data for the fix too, all is well.In situations where workload is high, one needs to avoid task saturation, and programming FMC is something that easily creates that daunting situation. However, flying the missed in LNAV and LVL CHG (this one after the a/c is clean, in the 737NG as opposed to 757) is good practise.Tero

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Hi Tero, woww... I must say you guys are the best!As a matter of fact it did help and I thank you again.David

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Hi Timothy, thanks you for the info and can't wait to fly your upcoming tutorial but man I would really love to see this aspect implemented in the fmc for the SU3 realease.It definetely would add better realism to the sim, not that it's lacking any but I really feel that PMDG sould focus on this instead of wanting to implement ACARS funcionality first. No offense this is just a thought and wouldn't be suprised to get both in SU3 knowing PMDG.Thank you very much for the practical advice and for your efforts with the tutorial.Happy flying,David

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"If initial maneuvering is required during the missed approach, accomplish the missed approach procedure through gear up before initiating the turn."Huh? Initial maneuvering? Through gear up? Initiating what turn?Anyone else having problems understanding this?Thanks.Cheers.Ian.

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Ian,It simply means that should there be some obstacles or something else requiring a low-altitude turn during the missed, the aircraft should not start the turn until gear is up, ie. after establishing a positive rate of climb, and the gear is up. A common occurrence ? Hardly. But possible, nonetheless.Tero

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Thanks Tero, this information is extremely useful, thanks for sharing :-) Next time I have to call a missed approach at Madeira, it should turn out better than the last lol

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>Timothy,>>You will never want to use V/S mode for a go-around. Never>ever. It's not speed protected.Sorry, I was not clear. I wasn't trying to imply that one would use V/S during the initial missed approach, for the reason you mention.However, once you're up and away from the airport, and clean, as you head for the missed approach holding point, you may choose to use the V/S mode for climbs if you're needing a specific climb rate.

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Hi Tero,firstly thank you for the useful info! I just think that in the NGs (contrary of the 767) the V/S mode is speed protected. That was, at least, what IZ told us some weeks ago, and there is something about that in the OPS Manual.http://forums.avsim.net/user_files/60292.jpgKind regards,Jorge Niny

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Jorge,WOW! I did not know this. I'm very new to the 737NG myself.No wonder it's called NG then, huh ? :)Terops. the manual doesn't recommend using V/S for go-arounds, though ;)

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>Hi Tero,>>firstly thank you for the useful info! I just think that in>the NGs (contrary of the 767) the V/S mode is speed protected.>That was, at least, what IZ told us some weeks ago, and there>is something about that in the OPS Manual.>>http://forums.avsim.net/user_files/60292.jpg>>Kind regards,>Jorge Niny>V/S is protected for underspeed, I'm not sure about overspeed. Anybody got a reference?

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Indeed, what Tero says, this is obstacle related. It may well be possible that you need to turn before reaching 400ft above the ground. This is usually not a problem when doing a non-eventful go-around, but can be very critical when you have an engine failure during the go-around.As a good pilot, you need to have that in the back of your head when starting the approach. If you do not, you might find yourself in an overwhelming situation when you do get an explosive engine seizure while applying go-around thrust (and causing a very low-speed, high asymmetric thrust situation anyway, which is a tough situation even without critical terrain).Of course, engine failures don't occur in FS unless you've manually enabled that option, in which case you're prepared for it anyway.So basically, real-life flying takes all those things into account and has procedures that provide for safety during critical failures, that may not make much sense when flying a simulated flight which guarantees absence of those failures.Furthermore, on the missed approach, V/S is never used. Just accelerate to speed-up (minimum clean speed for flaps up) when above 1000 ft AGL and select VNAV for the most accurate following of complex missed approach procedures. V/S has overspeed and underspeed protection, it will change to LVL CH. Coming from the 757, I still don't like the gratuitous use of V/S (just like in the 767/777/744), but the autopilot in the 737NG is very crude and the LVL CH mode is quite crude as well (ie. uncomfortable).

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>Furthermore, on the missed approach, V/S is never used. Just>accelerate to speed-up (minimum clean speed for flaps up) when>above 1000 ft AGL and select VNAV for the most accurate>following of complex missed approach procedures. >But since we can't do that in the sim yet (VNAV won't engage after the route is complete), we're stuck with LVL CHG or V/S.

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