When you intercept the LOC , you press APP

 

It's correct?

 

If you are maintaining 3000ft with ALT HLD or ACQ or whatever, and the position of the glideslope is thousands of feet below you, pressing the APP button won't teleport your plane down to where the glideslope is, or initiate a 4000ft/min decent rate to get down to the glidepath.

 

If you are at 4000ft at 2 miles from the runway, and you press the APP mode, you will fly over the runway at 4000ft. Because you are tracking the localizer you will be 'exactly' over the runway very accurately tracking the centreline, but you will still be at 4000ft high.

 

you need to press the APP button when you are BELOW the glideslope. 12 miles at 3000ft type of thing. If you press it when you are above the glideslope, you were either too late pressing the button, or too high, or both.

 

It's all about situational awareness. Know where you are, and if you are asking the autopilot to do something that's even possible.

One note that may be be obvious but I thought given the discussion its worth mentioning, you don't want to enable APP mode unless you have been cleared for the approach. :-)

Yep, there is that. You might be about to receive a dogleg vector for spacing or something, so popping straight into the localizer/glideslope might have just forced yourself, or someone else, into a "Discontinue approach, climb 4000ft turn left heading xxx, left late downwind runway xx.

If you are maintaining 3000ft with ALT HLD or ACQ or whatever, and the position of the glideslope is thousands of feet below you, pressing the APP button won't teleport your plane down to where the glideslope is, or initiate a 4000ft/min decent rate to get down to the glidepath.

 

If you are at 4000ft at 2 miles from the runway, and you press the APP mode, you will fly over the runway at 4000ft. Because you are tracking the localizer you will be 'exactly' over the runway very accurately tracking the centreline, but you will still be at 4000ft high.

 

you need to press the APP button when you are BELOW the glideslope. 12 miles at 3000ft type of thing. If you press it when you are above the glideslope, you were either too late pressing the button, or too high, or both.

 

It's all about situational awareness. Know where you are, and if you are asking the autopilot to do something that's even possible.

Yep, there is that. You might be about to receive a dogleg vector for spacing or something, so popping straight into the localizer/glideslope might have just forced yourself, or someone else, into a "Discontinue approach, climb 4000ft turn left heading xxx, left late downwind runway xx.

Thanks so much for the detail!

APP mode should not be selected until:

 

• the ILS is tuned and identified

• the airplane is on an inbound intercept heading

• both localizer and glide slope pointers appear on the attitude display in the proper position

• clearance for the approach has been received.

 

Glide slope may be captured before the localizer in some airplanes.

The glide slope may be captured from either above or below.
Glide slope capture does not occur if the intercept angle to the
localizer is greater than 80°. The maximum intercept angle for the
localizer is 120°. To avoid unwanted glide slope capture, LOC mode may
be selected initially, followed by the APP mode.

When using LNAV to intercept the final approach course, ensure raw
data indicates localizer interception to avoid descending on the glide
slope with LOC not captured. If needed, use HDG SEL/TRK SEL or HDG
HOLD/TRK HOLD to establish an intercept heading to the final approach
course.

 

If you followed your approach spot on profile, 99,9% of the times you will arm APP only.

Not LOC (on an ILS approach, obviously..)

Man this App is confusing me.. I tried to land on ILS 7 at MKJS.. man I clicked approach and went to omaxi 3 and then it flew me there and it went off track.. I wish I had somebody to show me... so tedious.

tried another attempt at ILS 7 at mkjs coming in from Bahamas coming in from North East before I take off from my nn I set the approach to be at ils 7 omaxi 3. so I guess I wont need to input it when I reach closer it flew at the last waypoint which sia and the plane wouldn't turn to omaxi. can someone tell me what I am doing wrong? thanks

 

 

can someone tell me what I am doing wrong?

 

I don't mean to be rude, but there is a lot of knowledge that is lacking here, particularly in regards to approaches.

 

I highly suggest these tutorials/lessons to help you fill in the gaps of knowledge:

http://pilotcerts.laartcc.org/page/ratings

 

Again, I'm not trying to be mean, but it's hard to offer support when there's background knowledge missing.  This is complex stuff, and without knowing the detail, us rambling on about when and how to engage the APP mode is just going to confuse you more.

I don't mean to be rude, but there is a lot of knowledge that is lacking here, particularly in regards to approaches.

 

I highly suggest these tutorials/lessons to help you fill in the gaps of knowledge:

http://pilotcerts.laartcc.org/page/ratings

 

Again, I'm not trying to be mean, but it's hard to offer support when there's background knowledge missing.  This is complex stuff, and without knowing the detail, us rambling on about when and how to engage the APP mode is just going to confuse you more.

 

No your not being rude. I went to the site but I didnt understand what it was saying.

If you coukd fly that route you would see the route ending at sia then it says route discontinued on the fmc. Still trying and learning to understand this approach. I know u must be annoyed at me by asking. I like to aplogize. Respect to you and your knowledge.

 

 

I know u must be annoyed at me by asking. I like to aplogize. Respect to you and your knowledge.

 

Not annoyed at all.

 

 

 

I went to the site but I didnt understand what it was saying.

 

The site has 11 lessons to help you go from nearly zero knowledge (starting with VFR basics), and working up through some IFR fundamentals (which is what you'd need to fly the large aircraft like the 777).

 

 

 

If you coukd fly that route you would see the route ending at sia then it says route discontinued on the fmc.

 

DISCONTINUITY is normal.  It is often there for cases where ATC provides you vectors between the end of your route (with or without a STAR) and the beginning of your approach.

 

Each lesson on that site has a video associated with it, along with a description of what the lesson is supposed to accomplish.  The main important thing I was trying to get you to do is just try those offline.  This video should be particularly helpful in giving you a better understanding of what an approach is all about, and the terminology associated with the various aspects:

http://pilotcerts.laartcc.org/object/zla_i1_video.html

disconutiy is a pain in the butt. you always have to correct it by typing in the route again.. if u have disconutiy the route will not be active or the aircraft wont go accordingly especially if your landing

I tried this now I watched the videos thanks to my buddy up there who helped me with this. your glidecope egins at the second star on the chart your firstoen is your LOC and when you reach the second star you hit app and maintain that altidude. But my question again do u leave LNAV on when you hit APP? let me know.

Formally the coverage area is 25nm for the localizer and 10nm for the glideslope.

In the U.S. it is 18 nm within 10 degrees, and 10 miles over 10 degrees to 35 degrees.

If a greater distance is needed, then frequency protection has to be assessed, and a flight inspection performed for the required greater distance (known as extended service volumne of "ESV") The glideslope is flight inspected to the P-FAF.

The localizer parameters are covered by the FAA in the U.S. Aeronautical Information Manual, Section 1-1-9 b. 5

 

For Boeing and Airbus do as the FCOM says, which is APP for the ILS. The airplane will not capture the GS first,as it says on the FCOM,also.

 

 

disconutiy is a pain in the butt. you always have to correct it by typing in the route again..

 

Nope.  You just select the waypoint after the discontinuity and line select it "on top" of the discontinuity (or at the top of the LEGS page if told to proceed direct to that fix).

 

 

 

if u have disconutiy the route will not be active or the aircraft wont go accordingly especially if your landing

 

They really aren't.  They're there for a reason, and the reason is as I stated before:

It's a part of the flight where ATC provides vectors in a lot of cases.

 

 

 

But my question again do u leave LNAV on when you hit APP?

 

Of course, the answer is not that simple:

The best course of action is to use HDG SEL to put yourself on an intercept course (a controller is likely vectoring you at this stage, so you should be on HDG SEL anyway).  You then "arm" APP by selecting it, and the AP will leave the HDG SEL mode active until it is ready to capture the LOC.  Same goes for LNAV (it will remain in LNAV until APP mode can capture the LOC), but the problem is that if the angles aren't right, it may remain in LNAV.

If I am left to select my own intercept heading, I myself use a rule of thumb of approx 30deg off approach heading.

 

Regards.

Nope.  You just select the waypoint after the discontinuity and line select it "on top" of the discontinuity (or at the top of the LEGS page if told to proceed direct to that fix).

 

 

 

They really aren't.  They're there for a reason, and the reason is as I stated before:

It's a part of the flight where ATC provides vectors in a lot of cases.

 

 

 

Of course, the answer is not that simple:

The best course of action is to use HDG SEL to put yourself on an intercept course (a controller is likely vectoring you at this stage, so you should be on HDG SEL anyway).  You then "arm" APP by selecting it, and the AP will leave the HDG SEL mode active until it is ready to capture the LOC.  Same goes for LNAV (it will remain in LNAV until APP mode can capture the LOC), but the problem is that if the angles aren't right, it may remain in LNAV.

Okay kind of understand about discontinuity cause everytine it comes up it shows vectors so the next waypoint will havw to be inputted on top disconuity on the fmc to actovte it to your waypoint to bring you in.

 

Off topic question does anybody know why sqwak box freezes fsx? Is there a fix for this. Let me know thanks.

 

Thank sir for your help. I can spread my knowledge and do more flying of 777. Thank you.

 

 

Off topic question does anybody know why sqwak box freezes fsx? Is there a fix for this. Let me know thanks.

 

Make sure to load it from the Start menu and not from the FSX Menus.  The .dll that they wrote to load it out of FSX has a problem with it.  Starting it from the Start menu will avoid this issue completely.