Advice on how to be stable by 1000 feet. What NOT to do?
Ut Sementem Feeceris
WST.
Picture the scene, you're cleared to descend to 2000' and "further with the glide" but you're already above the glideslope. You set 2000' and select V/S -1500 FPM but just when you're at "half dot high" on glide the FMA annuciates ALT*. This is because you have a high rate of descent and the autoflight system anticipates the level off...... so the aircraft starts to level and increase thrust
The correct method to avoid this is to set the altitude above your current altitude BUT YOU MUST ARM THE APPR!!!!!!!! IF YOU DONT YOU HAVE NOTHING TO STOP YOU DRIVING INTO THE GROUND.
So GS from above is:
1. Configure - drag to combat the increased rate of descent - Gear + F2 works.
2. Set the altitude above your current.
3. V/S -1500' FPM (2000'FPM is ok further out on the approach)
4.ARM THE APPROACH so you don't fly through the glideslope.
If it isn't going to work...... go-around..... don't try and make it work.
A4
Picture the scene, you're cleared to descend to 2000' and "further with the glide" but you're already above the glideslope. You set 2000' and select V/S -1500 FPM but just when you're at "half dot high" on glide the FMA annuciates ALT*. This is because you have a high rate of descent and the autoflight system anticipates the level off...... so the aircraft starts to level and increase thrust
The correct method to avoid this is to set the altitude above your current altitude BUT YOU MUST ARM THE APPR!!!!!!!! IF YOU DONT YOU HAVE NOTHING TO STOP YOU DRIVING INTO THE GROUND.
So GS from above is:
1. Configure - drag to combat the increased rate of descent - Gear + F2 works.
2. Set the altitude above your current.
3. V/S -1500' FPM (2000'FPM is ok further out on the approach)
4.ARM THE APPROACH so you don't fly through the glideslope.
If it isn't going to work...... go-around..... don't try and make it work.
A4
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The most important thing in the cockpit is common sense. if the engines are starting to spool up or when the speed is still a bit high but configured, no need at all to go around. Common sense has priority over blind slave of the procedure. this is not to say that you should not aim for a completely stabilised aircraft according your SOP.
Hi WhySoTough.
Often you will get the scenario where you are LOC established, say at 3,000', all fine and good. However, then ATC realises that they've left you a bit high or a bit close, and so give you clearance to "descend 2,500' and further with the glide".
So you dial in 2,500' and pull to descend, and also arm the glideslope. You now have G/S and ALT modes both armed in blue. But, as you watch the glideslope lozenge coming down towards the altitude lubber line, the 2,500 blue alt box also comes up towards the same lubber line. Sod's law says that the aircraft will get down to the cleared altitude before the glideslope and go into ALT*. While it is doing this, it will ignore the glideslope completely and you will fly level, past the glideslope intercept point, leaving you above the glide!
The way around this, if you see it coming, is to select and pull a V/S range between say -500 and -200, so that you descend more slowly, and will therefore reach the glideslope before the selected altitude. Then the aircraft will capture the glide, go into GLIDE* and ignore the altitude. This is a good time for you to set the missed approach alt.
I hope that makes sense? - It's much easier to do than explain!
U
Often you will get the scenario where you are LOC established, say at 3,000', all fine and good. However, then ATC realises that they've left you a bit high or a bit close, and so give you clearance to "descend 2,500' and further with the glide".
So you dial in 2,500' and pull to descend, and also arm the glideslope. You now have G/S and ALT modes both armed in blue. But, as you watch the glideslope lozenge coming down towards the altitude lubber line, the 2,500 blue alt box also comes up towards the same lubber line. Sod's law says that the aircraft will get down to the cleared altitude before the glideslope and go into ALT*. While it is doing this, it will ignore the glideslope completely and you will fly level, past the glideslope intercept point, leaving you above the glide!
The way around this, if you see it coming, is to select and pull a V/S range between say -500 and -200, so that you descend more slowly, and will therefore reach the glideslope before the selected altitude. Then the aircraft will capture the glide, go into GLIDE* and ignore the altitude. This is a good time for you to set the missed approach alt.
I hope that makes sense? - It's much easier to do than explain!
U
Last edited by Uplinker; 24th Oct 2012 at 02:15.
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AA, good point about the open descent scenario I talked about. That is why I specified only to FAF altitude and yes, you would have to arm the APP button.
We have a lot of slam dunks in the US. The approach into SNA is typical of what I am speaking of. You are coming in over the Coast mountains about 15 miles from the runway. The MVA is 5700' for a sea levelish (50') airport. If you get the left base entry to the localizer you have to lose 3500 feet in about 8 or 9 miles. That's the scenario I was asking about.or our approach into PANC at night. Over the Chugash mountains at 8000 feet, descending over the water abeam the airport at 6000', cleared the approach. You have to dump it down with flaps 2 and speed brakes, the gear if you keep 250kts until base. It becomes a challenge to manage the energy properly, a challenge that makes the job a lot more than "just driving the bus".
As for getting on the trainee for flaps 1 at 13 miles? Utter stupidity. Unless you are number one with no one else around I would expect that ATC wants you at 180 to 210 kts. That's calling for flaps 1.
Be conservative but also be willing to push your comfort level. The idea is to minimize drag and keep fuel flow to a minimum until you must be spooled and stable, be it at 1000' AGL or 500' AGL. Hopefully you as a new guy will have an experienced check airman that will be competent enough to let you work this out for yourself.
Remember,a experienced pilot is just someone who screwed up but lived to learn the lesson. (tongue in cheek there for the humor challenged).
We have a lot of slam dunks in the US. The approach into SNA is typical of what I am speaking of. You are coming in over the Coast mountains about 15 miles from the runway. The MVA is 5700' for a sea levelish (50') airport. If you get the left base entry to the localizer you have to lose 3500 feet in about 8 or 9 miles. That's the scenario I was asking about.or our approach into PANC at night. Over the Chugash mountains at 8000 feet, descending over the water abeam the airport at 6000', cleared the approach. You have to dump it down with flaps 2 and speed brakes, the gear if you keep 250kts until base. It becomes a challenge to manage the energy properly, a challenge that makes the job a lot more than "just driving the bus".
As for getting on the trainee for flaps 1 at 13 miles? Utter stupidity. Unless you are number one with no one else around I would expect that ATC wants you at 180 to 210 kts. That's calling for flaps 1.
Be conservative but also be willing to push your comfort level. The idea is to minimize drag and keep fuel flow to a minimum until you must be spooled and stable, be it at 1000' AGL or 500' AGL. Hopefully you as a new guy will have an experienced check airman that will be competent enough to let you work this out for yourself.
Remember,a experienced pilot is just someone who screwed up but lived to learn the lesson. (tongue in cheek there for the humor challenged).
Ut Sementem Feeceris
Uplinker said:
I think you've just confused the issue a bit there Uplinker! 
If you're below the glide ("lozenge coming down towards the altitude lubber line") and the aircraft enters ALT* whilst you have GS armed.....it will capture the Glide - ALT* doesn't disarm GS (blue). The only caveat there is that the glide must have been armed for approx 2-3 seconds at least prior to GS* otherwise it will fly through (something to do with an integrity check). Your method of V/S -200'/min is spot on to prevent the ALT* but if it does occur its not an issue. Perhaps on the older 'Bus's it is?
The scenario where problems occur is when you're above the glide with a lower ALT set set and the risk of early ALT* prior to GS* - see my previous post.
A4
So you dial in 2,500' and pull to descend, and also arm the glideslope. You now have G/S and ALT modes both armed in blue. But, as you watch the glideslope lozenge coming down towards the altitude lubber line, the 2,500 blue alt box also comes up towards the same lubber line. Sod's law says that the aircraft will get down to the cleared altitude before the glideslope and go into ALT*. While it is doing this, it will ignore the glideslope completely and you will fly level, past the glideslope intercept point, leaving you above the glide!
If you're below the glide ("lozenge coming down towards the altitude lubber line") and the aircraft enters ALT* whilst you have GS armed.....it will capture the Glide - ALT* doesn't disarm GS (blue). The only caveat there is that the glide must have been armed for approx 2-3 seconds at least prior to GS* otherwise it will fly through (something to do with an integrity check). Your method of V/S -200'/min is spot on to prevent the ALT* but if it does occur its not an issue. Perhaps on the older 'Bus's it is?The scenario where problems occur is when you're above the glide with a lower ALT set set and the risk of early ALT* prior to GS* - see my previous post.
A4
Last edited by A4; 24th Oct 2012 at 07:51.
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All this talk of gear.....presumably everyone has the speedbrake right out already ?
I'd also say I saw alot of folks realise they were high/fast, and tickle the speedbrake out, stick it back in......2 minutes later out again.....if it's going pear shaped get it out and keep it out until the situation is definitely sorted.
I'd also say I saw alot of folks realise they were high/fast, and tickle the speedbrake out, stick it back in......2 minutes later out again.....if it's going pear shaped get it out and keep it out until the situation is definitely sorted.
Hi A4,
I agree that I may have confused WhySoTough with a refinement that he is probably not ready for yet.
However, on the Airbusses I fly; ALT* does block G/S capture if the two points are co-incident in time and space. While ALT* is active and the aircraft is capturing the selected altitude, it will ignore the glide and not capture it - I've proved that several times, to my own embarrasment
! - then you have to intercept the glide from above, (or go manual).
Perhaps they fixed this glitch in later models?
U
I agree that I may have confused WhySoTough with a refinement that he is probably not ready for yet.
However, on the Airbusses I fly; ALT* does block G/S capture if the two points are co-incident in time and space. While ALT* is active and the aircraft is capturing the selected altitude, it will ignore the glide and not capture it - I've proved that several times, to my own embarrasment
! - then you have to intercept the glide from above, (or go manual).Perhaps they fixed this glitch in later models?
U
Last edited by Uplinker; 24th Oct 2012 at 17:01.
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In order to avoid an unstabilized approach, you need every day to evaluate the variables of each approach. For instance:
weight
wind
traffic behind
G/S capture altitude
In a day with high weigh, tail wind, capture at 1,700 ft and a traffic behind pushing you... You better be proactive or it is likely you will be unstabilized if you "sleep" and just do what you do every day.
In a day with low weight, head wind, capture at 3,000, you are number one and number two is 10 minutes away... Relax, man.
Get used to take into account those variables, and others that I may have forgotten to mention, and act accordingly. In the 320, when some of those variables are against me, I configure without delay, flaps 1 so as to be with S no later than at the G/S, flaps 2 if at or below 2,000 ft capture. And I keep configuring non stop until fully configured. If there is maintain 160 til 4, managing by 4 with full should do. If there is strong tailwind and high weight and you feel the engines almost idle, it will take long to decelerate: manage speed at 6 or 5 miles instead.
In the relaxed day I try to make low drag low noise, I delay flaps, gear, etc... But don't relax too much. Aim to be stabilized at 1,500 ft, so you have a buffer.
weight
wind
traffic behind
G/S capture altitude
In a day with high weigh, tail wind, capture at 1,700 ft and a traffic behind pushing you... You better be proactive or it is likely you will be unstabilized if you "sleep" and just do what you do every day.
In a day with low weight, head wind, capture at 3,000, you are number one and number two is 10 minutes away... Relax, man.
Get used to take into account those variables, and others that I may have forgotten to mention, and act accordingly. In the 320, when some of those variables are against me, I configure without delay, flaps 1 so as to be with S no later than at the G/S, flaps 2 if at or below 2,000 ft capture. And I keep configuring non stop until fully configured. If there is maintain 160 til 4, managing by 4 with full should do. If there is strong tailwind and high weight and you feel the engines almost idle, it will take long to decelerate: manage speed at 6 or 5 miles instead.
In the relaxed day I try to make low drag low noise, I delay flaps, gear, etc... But don't relax too much. Aim to be stabilized at 1,500 ft, so you have a buffer.
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The Airbus doesn't need ATC to fly an approach. It can do that by it's self. ATC need to be a "king in his own castle".
Some things to follow.
1. never let ATC fly your airplane. If you don't agree with an instruction, don't accept it.
2. The 320 (if you are on the green approach line) will automatically activate the approach at 15 nm from touch down.
3. Situation awareness is paramount. You must know where you are at all times. Use you RMI.
4. A 3 degree slope is 318 feet down for every NM forward. That's the gradient.
5. If you have to capture the GS from above, the FCOM says; altitude alert above aircraft altitude, ILS (GS) armed, select 1500 fpm down. This way you won't run into the ALT* problem. Further to that, rate of descent and ground speed work together. The faster the GS, the greater the ROD has to be. On the 320 it's simple. Look at the GS on the ND (lets say it's 170 kts), add one to 17 = 1800 FPM, your correct ROD for a 6 degree slope. This allows 3 deg slope to capture a 3 deg slope.
So GS140 = 1500 fpm, 150 = 1600 fpm etc. Max is 2000 fpm. No guess work, and no hassle. Everything to do with flying and computers is mathematical.
Have fun.
T
Some things to follow.
1. never let ATC fly your airplane. If you don't agree with an instruction, don't accept it.
2. The 320 (if you are on the green approach line) will automatically activate the approach at 15 nm from touch down.
3. Situation awareness is paramount. You must know where you are at all times. Use you RMI.
4. A 3 degree slope is 318 feet down for every NM forward. That's the gradient.
5. If you have to capture the GS from above, the FCOM says; altitude alert above aircraft altitude, ILS (GS) armed, select 1500 fpm down. This way you won't run into the ALT* problem. Further to that, rate of descent and ground speed work together. The faster the GS, the greater the ROD has to be. On the 320 it's simple. Look at the GS on the ND (lets say it's 170 kts), add one to 17 = 1800 FPM, your correct ROD for a 6 degree slope. This allows 3 deg slope to capture a 3 deg slope.
So GS140 = 1500 fpm, 150 = 1600 fpm etc. Max is 2000 fpm. No guess work, and no hassle. Everything to do with flying and computers is mathematical.
Have fun.
T
