I'm flying a 737, cleared on runway 9L for an ILS approach at PHL. I'm on final with AP on. Usually, I'll take over before intercepting the localizer and fly it in. But when I try to use approach AP, nothing happens. What am I doing wrong? Should I turn off heading, altitude, and speed prior to engaging approach on the AP?
This should help, it's my handy dandy ILS guideline, it contains full ILS instructions, as well as how to use the APP mode on the autopilot.
1. When ATC says something liek "WifeBeater 767, you are 32 Miles away. Turn right heading 105, descend and mantain 2,500 feet, cleared ILS runway 36R Approach". You have to click on your MAP icon in your cockipt. Then, move your mouse over the destination airport. Mind you, the airport MUST have the ILS feathers (thes are the green things that point to the runway). Double click on the airport. A list will show up. Scroll down the list untill you see a chart that shows Runway numbers. FInd 36R, or whatever your runway is. You look to the right and see a radio frequency. We'll use 100.100 because its easy to remember. Don't forget the frequency.
2. Open up your Radio Stack, and enter in 100.100 in the NAV1 Radio, usually the righmost radio number is the one that can be messed with. After you enter it 100.100, using the mouse wheel or clickin it. Press the button that looks like thsi somewhat, its in the middle of the 2 radio displays <-----> That changes the NAV1 Radio frequency from whatever it was, to what it is now (100.100)
3.Turn on the NAV1 Radio by clicking the switch at the bottom of the radio stack, unless its already on, like with the LearJet.
4. If you have Autopilot, and you are using GPS to follow waypoints, switch the NAV/GPS button back to NAV!!!! YOU CANT FORGET TO DO THAT!!! YOU'LL BURN AND DIE IF YOU DONT!!
5. Follow ATC directions to approach. Now, when you approach the Runway, you will see the pink arrows near your attitude indicator move...usually Heading first, then Altitude. Simply fly in the directon and atitude of the pink arrows intull they center themselves, that means you're on the glideslope!
6. If you wanna use the autopilot to fly the approach, simply follow steps 1-4, then click the APPR button on the autopilot panel.
Hi Fire, actually, that's the ILS approach I use. Everything you've listed 1 through 5 I've executed. But when it comes time to engage the APP, it doesn't do anything. Could it be that I have to turn off heading, altitude, and speed before engaging APP? Thanks for the help fire...
No, it should work just fine. Make sure that the NAV1 Radio is on, (the button is lit) If you can, take a screenshot of the cockpit, showing the autopilot, Radio stack, and GPS for me, but make sure that I can also see the ILS needles in the atitude indicator
If you are close to where you should be on the slope, the approach feature of the A/P should engage and work. Make sure you have the ILS frequency dialed in on the No# 1 nav. I always hand fly the approach. I find that I can do much better keeping on the slope by hand than the A/P, especially when I'm hanging out the flaps on app. On every commercial flight I've been on, the pilots start hanging out the flaps quite a ways from the rnwy. They do it one notch at a time. As you hang out the flaps you must change pitch angle to stay on the slope. The A/P does not anticipate flap extension, it only reacts after the flap change has caused the craft to deviate from glideslope. The pilot however can anticipate it.
Hey Lead and Radar... Yeah, usually I'll take over and fly the final once I've intercepted the localizer (inside the feathers). I was curious about the APP feature and tried it, but all that happens is a sudden change in bank angle and pitch, going almost haywire. It seems as if it's trying to stay within the localizer and guideslope... The thing is I was already on course in the localizer. How do I take shots while flying? I'll see if I can take that pic... Thanks guys...
Unless you are real close to glide path, the A/P will almost go to extremes to get centered, I don't think that that modeling is at all accurate. Were an A/P to do that in real life, it would certainly scare the piss out of the passengers and would likely precipitate a crash. NO ONE would be happy in either case.
It is advisable to use LOC first, once on the Localiser engage APP providing you are still under the GS beam. Additionally approach the localiser at 45* or less otherwise FS finds it difficult to centre you on the LOC.
Hey guys, I've tried the APP mode of AP, but still to no avail. It has a mind of its own. I think I'm doing everything I'm supposed to. At least I think I am. Okay, I have the correct ILS frequency (I see the points coming together when I intercept, and hear marker warnings); I'm approaching the localizer at about 180 KTS, 10% flaps extended, gear down; when I'm in the localizer I bleed the speed to about 160 KTS, extending the flaps to 50%, or whatever I need. I intercept the localizer at the assigned altitude as per ATC, and once I'm in the localizer, I start descending at about 800 FPM. Is there a step I'm missing? I'm flying the 737-400, is their anyone that flies this Boeing? Am I missing a procedure? Or does anyone have the correct final procedures for the 737? Thanks guys...
You say start descending at 800fpm when on the LOC, do you mean you instigate the descent? What should happen is when you are on the LOC, when the glideslope indication "dot" is at least a couple of dots high engage the APP mode. Personally I only have flap 10, gear up at this stage speed depends on what I am flying (providing I am intercepting at 5-6 mile) Just before GS centres I take the gear, flap 20. (30 or 40* if and when required)
Thanks for all the help guys, I still have problems with APP, but i'll have to deal with it, besides, I can always fly it manually... lol
I used to have a similar problem, but with some help from the guys here I found out that my problem was that I simply had too high speed. When I slowed down to 145 kts just before intercepting the glideslope, it all went fine. At higher speeds, like 160, it started to pitch down, but lost track of the glideslope.