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Thread: Experts help please; FSX SE Approach Hold Usage

  1. Default Experts help please; FSX SE Approach Hold Usage

    Hi, been away from flying for 5 years. Just bought FSX SE and getting back into it. Regarding Approach Hold, I have watched several videos on YouTube and it's confusing. Some guys suggest that while making an ILS approach/landing that you turn on the approach hold button only after the "bug" starts to drop and move down on the display. One of them even says that you need to turn it on when the "bug" hits the horizon line to ensure your proper landing at the correct point of the runway. Then there are many others that suggest to turn on the approach hold as soon as you hear the Morse code beeps, in essence letting the approach hold handle turning the plane toward the runway and down to it using the glide scope. Everybody agrees to do all these or any of these steps while below the glide scope and within 90 degrees angle of the runway. So, what is the correct procedure to follow? I've tried it both ways since getting back into flying and hitting the approach hold on short finals (dirty and already lined up) seems to work fail safe. Trying to do it earlier, as suggested by many videos is hit and miss as a few times the glide scope is lost after turning towards the runway. THANKS for your help experts!

  2. #2
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    Not an expert, but I normally turn on the APP/APR button right after ATC has given me my final turn to within 30 degrees of the runway. Hopefully, I am within 18 miles or so from the runway at this point. I find that capturing the Localizer is hap-hazard if more than 20, or so miles away. I normally fly an IFR flight plan.
    Mr Zippy Sent from my keyboard using "Whackamole", NudgeAKey + 2 Fingers

    Emachines T3418 AMD 3400+ processor 2GHZ/256KB L2 Cashe 2Gig Ram 160Gig HDD NVidia GEForce 6100 GPU Running WinXP Home Can't believe it still works! Running FSX Standard with SP1 and SP2

  3. #3
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    In the sim, assuming you're well below cruise speed, preferably at initial approach speed, you should be able to use NAV with ALTitude hold to intercept the localizer and then, assuming you're under the glideslope, switch to APPR (hopefully NAV and ALT lights go out). Be sure you're not too far to the side of the localizer and that your heading is within, say, 30º (preferably much less) of the final course when you hit APPR. And you MUST be outside the FAF (Final Approach Fix), usually the LOM (Locator Outer Marker), along with some additional means of identifying that point. Note that "short final" is generally used to mean very close in, perhaps under a mile for a jet, under ¼ mile, perhaps less, for light aircraft, so you're not on short final when outside the FAF.

    Listening to the beeps is useless (other than to know something is there, which your needle tells you anyway)*, since identification of the specific transmitter is the sole purpose of that morse code. It needs to be in APPR mode for the AP to capture and use the glideslope, so it must be on before intercepting the GS.

    Keep in mind that once in APPR mode the AP guides with greater sensitivity than in NAV mode, thus greater precision. Also, when tuned to a localizer, the receiver/CDI becomes 4 times as sensitive as that same receiver getting a VOR signal.



    * If you listen to the code and decipher the letters, then you can check against the letter ID printed on the chart to be sure it's the right one, otherwise it's pointless.

    Larry N.

    As Skylab would say:
    Remember: Aviation is NOT an exact Science!

  4. #4
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    Hopefully, I am within 18 miles or so from the runway at this point. I find that capturing the Localizer is hap-hazard if more than 20, or so miles away.
    That's fine for jets, but those distances are awfully far for the typical light aircraft, where a couple of miles (maybe a little less) outside the FAF, once established on the localizer, will be fine.

    Larry N.

    As Skylab would say:
    Remember: Aviation is NOT an exact Science!

  5. Default

    You can switch App hld on when the vertical bug and horizontal bug are both showing.
    You also have to be within a 30 degree angle with the extended centerline. (and not too far from the centerline.).
    You also need to be flying slowly. If your speed is too high the autopilot can not make the turns sharp enough. So, full flaps, and speed just below max full flaps speed.

    I usually move a bit closer to the centerline first myself. I can do that better then approach hold can.

    I start lining up well in time. 25 nm out if possible. (737 , 3000ft above ground.).

    I'm usually pretty well lined up 18 to 15 nm out. That's when I engage app hold.

    I then slow down further. On the final descent you won't be able to slow much if at all. And if you arrive at the runway too fast you may not be able to stop on it in time.
    (I aim for 145/135 knots in (default) 737.)

    Because I'm at 3000 ft AGL the descent will start at 10 Nm out.
    (glideslope goes up from the runway, towards you, at 300 ft per Nm.).

    During the descent the speed increases at first, but drops a bit again once you lower the gear.

  6. Default

    Thanks for the info and help! Good on you that your set-up still runs FSX, WOW! I am running an i7 at 3.4Ghz with 12 GB Ram, a huge HDD and a decent video card and it still looks nothing like all the crazy YouTube FSX videos out there that look like real life...

  7. #7
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    Quote Originally Posted by roundsaturn View Post
    Thanks for the info and help! Good on you that your set-up still runs FSX, WOW! I am running an i7 at 3.4Ghz with 12 GB Ram, a huge HDD and a decent video card and it still looks nothing like all the crazy YouTube FSX videos out there that look like real life...
    Most, if not all, of those "as real as it gets" Youtube videos have been massaged around with editing techniques that make it look far better than it really was.
    Mr Zippy Sent from my keyboard using "Whackamole", NudgeAKey + 2 Fingers

    Emachines T3418 AMD 3400+ processor 2GHZ/256KB L2 Cashe 2Gig Ram 160Gig HDD NVidia GEForce 6100 GPU Running WinXP Home Can't believe it still works! Running FSX Standard with SP1 and SP2

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