Air China 767 crashes in South Korea (April 2002)
Join Date: Aug 2001
Location: Australia
Posts: 72
Likes: 0
Received 0 Likes
on
0 Posts
In the slut
Your point 1. Since when have circling approaches been flown in IMC.
Is this a new procedure I have not been informed of. Please guide me to details of how one is to carry out this dubious manouvre.
GG
Your point 1. Since when have circling approaches been flown in IMC.
Is this a new procedure I have not been informed of. Please guide me to details of how one is to carry out this dubious manouvre.
GG
GG
A circling approach by definition is a manouvre to land in less than VMC.
You're mistaking VMC with VISUAL. At 100ft on a cat2 ILS you have to be Visual to land, but that doesn't mean you are not still in IMC.
A circling approach by definition is a manouvre to land in less than VMC.
You're mistaking VMC with VISUAL. At 100ft on a cat2 ILS you have to be Visual to land, but that doesn't mean you are not still in IMC.
Join Date: Mar 2002
Location: India
Posts: 346
Likes: 0
Received 0 Likes
on
0 Posts
HIALS:
Some interesting points there.
However, two questions remain:
1) Does anyone really know CAAC's true air safety record. For a considerable time (even beyond the "Great Leap Backwards" era) it was widely accepted that many tragedies went unreported - particularly those that did not involve any foreign casualties.
2) Which CAAC unit did the aircraft belong to that was said to have crashed with Lin Biao on board?
Some interesting points there.
However, two questions remain:
1) Does anyone really know CAAC's true air safety record. For a considerable time (even beyond the "Great Leap Backwards" era) it was widely accepted that many tragedies went unreported - particularly those that did not involve any foreign casualties.
2) Which CAAC unit did the aircraft belong to that was said to have crashed with Lin Biao on board?
Join Date: Mar 2002
Location: Wybacrik
Posts: 1,190
Likes: 0
Received 0 Likes
on
0 Posts
Apart from the bleeding hearts , the tree huggers, those who play the racist game and the amateur pilots ,this has been a reasonably well informed debate...lead of course,as usual, by experienced professional airline pilots!
Anybody who has flown the 36L approach into Kimhae followed by the circling approach for 18R knows that it is a definite "no no"...especially in conditions of reduced vis!
Any professional pilot going there for the first time and looking at the letdown plate with the associated high terrain would give the circling approach a miss! Especially with a ILS to 36L ,or 36R, available.
Having flown the approach many times, albeit from the back of a simulator, I am no longer amazed when we hit the ground...as Air China apparently did!
A previous poster with similar knowledge of the area has stated that unless one had local knowledge then a disaster would surely happen!
Now, doesn't that also say something?
High speed jet transport aircraft should not fly circling approaches! Flogging a 737,767 etc, in min vis, 800 ft or so AGL is a recipe for disaster...and there is usually no need for it!
How many times in your career has that been the only option available to you?
Anybody who has flown the 36L approach into Kimhae followed by the circling approach for 18R knows that it is a definite "no no"...especially in conditions of reduced vis!
Any professional pilot going there for the first time and looking at the letdown plate with the associated high terrain would give the circling approach a miss! Especially with a ILS to 36L ,or 36R, available.
Having flown the approach many times, albeit from the back of a simulator, I am no longer amazed when we hit the ground...as Air China apparently did!
A previous poster with similar knowledge of the area has stated that unless one had local knowledge then a disaster would surely happen!
Now, doesn't that also say something?
High speed jet transport aircraft should not fly circling approaches! Flogging a 737,767 etc, in min vis, 800 ft or so AGL is a recipe for disaster...and there is usually no need for it!
How many times in your career has that been the only option available to you?
Last edited by amos2; 20th Apr 2002 at 10:33.
Join Date: Aug 2001
Location: Australia
Posts: 72
Likes: 0
Received 0 Likes
on
0 Posts
Wiz
I think you are splitting hairs a bit. Technically correct none the less.
Jep definition of a circling app is :- “an extension of an instrument app procedure which provides for visual circling of the aerodrome prior to landing”. Jep ATC 104.
Jepp ATC 4.1.1 (pg 218) goes further in stating :-“ Visual manoeuvring (circling) is the term used to describe the visual phase of flight after completing an instrument approach……………
The point is, it is a VISUAL manouvre. I am quite well aware of the difference between Visual VMC and VFR, thanks.
Amos 2
The following comments are not related in any way to the recent accident, of which I have no extra knowledge and have no wish to comment. They are offered in response to your pontificating re circling approaches.
We should be so lucky as to never to have to do a circling approach in poor conditions. The reality is that in many parts of the world there is no option on many occasions, other than to cancel. I am sure all would applaud an ILS being mandatory equipment for every runway used by commercial aircraft, unfortunately we will all be long buried when that utopian ideal is achieved. Don’t forget that the reason a lot of runways do not have an ILS is because they cannot meet the ILS Approach Procedures Design Criteria. I am lucky in that I now usually only go to places with 12,000 ft parallels with ILS’s to burn. Unfortunately to a lot of our colleagues circling approaches are a daily fact of life.
A circling approach only becomes a health hazard when inappropriate procedures are applied. If you stay within the designated circling radius(as you are required to do), maintain your speed at or less than the mandated speed (as you are required to do), keep the runway in sight ( as you are required to do), keep one head out and one in to monitor sink rates and speed ( as you sensibly should) then the manoeuvre is far less dangerous than many other procedures we are required to demonstrate (single engine rejected landings with a turning engine out procedure for instance). I shudder when I read things like Holden’s procedure for circling, it sounds like he has his head inside the majority of the time and is not keeping track of the ever-changing view out the window. Remember this is a VISUAL manoeuvre and “after initial visual contact, the basic assumption is that the runway environment, (i.e., the runway threshold or approach lighting aids or other markings identifiable with the runway) should be kept in sight while at MDA/H for circling.” (Jep ATC 4.4 pg 219)
Above all, if at anytime you do not meet the visibility requirements turn via the runway to the missed approach heading, bug out without delay, and you will be able to confidently fly circling approaches and live to grow old and grey like me.
GG
I think you are splitting hairs a bit. Technically correct none the less.
Jep definition of a circling app is :- “an extension of an instrument app procedure which provides for visual circling of the aerodrome prior to landing”. Jep ATC 104.
Jepp ATC 4.1.1 (pg 218) goes further in stating :-“ Visual manoeuvring (circling) is the term used to describe the visual phase of flight after completing an instrument approach……………
The point is, it is a VISUAL manouvre. I am quite well aware of the difference between Visual VMC and VFR, thanks.
Amos 2
The following comments are not related in any way to the recent accident, of which I have no extra knowledge and have no wish to comment. They are offered in response to your pontificating re circling approaches.
We should be so lucky as to never to have to do a circling approach in poor conditions. The reality is that in many parts of the world there is no option on many occasions, other than to cancel. I am sure all would applaud an ILS being mandatory equipment for every runway used by commercial aircraft, unfortunately we will all be long buried when that utopian ideal is achieved. Don’t forget that the reason a lot of runways do not have an ILS is because they cannot meet the ILS Approach Procedures Design Criteria. I am lucky in that I now usually only go to places with 12,000 ft parallels with ILS’s to burn. Unfortunately to a lot of our colleagues circling approaches are a daily fact of life.
A circling approach only becomes a health hazard when inappropriate procedures are applied. If you stay within the designated circling radius(as you are required to do), maintain your speed at or less than the mandated speed (as you are required to do), keep the runway in sight ( as you are required to do), keep one head out and one in to monitor sink rates and speed ( as you sensibly should) then the manoeuvre is far less dangerous than many other procedures we are required to demonstrate (single engine rejected landings with a turning engine out procedure for instance). I shudder when I read things like Holden’s procedure for circling, it sounds like he has his head inside the majority of the time and is not keeping track of the ever-changing view out the window. Remember this is a VISUAL manoeuvre and “after initial visual contact, the basic assumption is that the runway environment, (i.e., the runway threshold or approach lighting aids or other markings identifiable with the runway) should be kept in sight while at MDA/H for circling.” (Jep ATC 4.4 pg 219)
Above all, if at anytime you do not meet the visibility requirements turn via the runway to the missed approach heading, bug out without delay, and you will be able to confidently fly circling approaches and live to grow old and grey like me.
GG
Join Date: Mar 2000
Location: Obvious
Age: 78
Posts: 301
Likes: 0
Received 0 Likes
on
0 Posts
One further observation about circling approaches and "protected" areas. Upon reflection it's rather farcical to lay down a 1.7nm (3.2km) protected area for cat C aircraft and then not have any significant buffer zone before you can bump into such a highly obtrusive obstacle of the order of the one that they hit (about 1.5kms further on). That 1.5kms at a representative 150 to 160kts groundspeed is equivalent to about a 15 second delay. The actual solution to not becoming a grease-spot on a mountain is to look for the minimum manoeuvring area (i.e. chew up the least airspace necessary) for getting safely around onto an abbreviated finals). It's that message that I am sure is just not getting across. Military pilots do very extensive training in low-level (bad weather) circuits specifically because they are exactly what the Doctor ordered - when it comes down to circling approaches.
Different to the non-precision approach (and in fact unique to the circling approach) is the concept that it's a visual flight phase but because the prevailing visibility can be very variable, you don't have to see where you're going (i.e. what's ahead) - as long as:
a. you maintain not below circling MDA until wings-level on finals and
b. remain within the protected area -in this case 1.7nm radius of the airfield reference point (the centroid of a line joining all runway thresholds) and
c. keep the landing threshold within sight - or immediately execute a missed approach (shortest way round climbing turn onto the MAP course).
...but of course the trick is in not exceeding that otherwise difficult to abide by 1.7nm max (cat C) due to wind, disorientation, distraction or procrastination. Therein lies the real hazard - and automation and EGPWS is of little use during low speed tightly manoeuvring flight in the approach configuration - it's all necessarily done with the Mk1 eyeball.
I've run into two different philosophies on a missed during circling. First was turn the shortest way onto the missed approach course and the second (which seems smarter) turn through the runway (i.e. the ARP) towards/onto the MAP course. The shortest way method would seem to put you outside the protected area too promptly, even though you will be established in the climb. One thing is for sure...knowing just when to chuck it in and throw it away is a real test of airmanship. Just like GF072 and the Alliance Air 737 at Patna found out, turning visually cross-cockpit onto a centre-line can be a real challenge. Stir in a tightening tailwind on base and you have all the ingredients for a major stuff-up.
Different to the non-precision approach (and in fact unique to the circling approach) is the concept that it's a visual flight phase but because the prevailing visibility can be very variable, you don't have to see where you're going (i.e. what's ahead) - as long as:
a. you maintain not below circling MDA until wings-level on finals and
b. remain within the protected area -in this case 1.7nm radius of the airfield reference point (the centroid of a line joining all runway thresholds) and
c. keep the landing threshold within sight - or immediately execute a missed approach (shortest way round climbing turn onto the MAP course).
...but of course the trick is in not exceeding that otherwise difficult to abide by 1.7nm max (cat C) due to wind, disorientation, distraction or procrastination. Therein lies the real hazard - and automation and EGPWS is of little use during low speed tightly manoeuvring flight in the approach configuration - it's all necessarily done with the Mk1 eyeball.
I've run into two different philosophies on a missed during circling. First was turn the shortest way onto the missed approach course and the second (which seems smarter) turn through the runway (i.e. the ARP) towards/onto the MAP course. The shortest way method would seem to put you outside the protected area too promptly, even though you will be established in the climb. One thing is for sure...knowing just when to chuck it in and throw it away is a real test of airmanship. Just like GF072 and the Alliance Air 737 at Patna found out, turning visually cross-cockpit onto a centre-line can be a real challenge. Stir in a tightening tailwind on base and you have all the ingredients for a major stuff-up.
Tailwind Effect on Circling
There has been talk of a 50 kt. tailwind. A 30 second downwind past the threshold of Rwy 18 plus a rate 1 turn to base produces 60 seconds under the influence of said 50kt. which pushes you an extra 0.83 nm past the threshold -- close to half of the 1.7nm maneuvering area.
Without some 18 degrees of drift correction on your base leg, you will still be getting blown out of the maneuvering area at up to 50 kt.
A 20 second downwind and a rate 2 turn yields 35 seconds which still eats up .49nm of the maneuvering area.
Sitting here in my living room, I'd have to spend some time with the aerodynamics textbook to calculate an appropriate timing for downwind past threshold and required turn rate given a certain approach speed and tailwind.
Perhaps there should be a set maximum tailwind in each category acceptable for performing a circling approach.
Once on final, the 40 kt loss of headwind would make for an interesting approach.
Without some 18 degrees of drift correction on your base leg, you will still be getting blown out of the maneuvering area at up to 50 kt.
A 20 second downwind and a rate 2 turn yields 35 seconds which still eats up .49nm of the maneuvering area.
Sitting here in my living room, I'd have to spend some time with the aerodynamics textbook to calculate an appropriate timing for downwind past threshold and required turn rate given a certain approach speed and tailwind.
Perhaps there should be a set maximum tailwind in each category acceptable for performing a circling approach.
Once on final, the 40 kt loss of headwind would make for an interesting approach.
Join Date: Mar 2001
Location: Wet Coast
Posts: 2,335
Likes: 0
Received 0 Likes
on
0 Posts
Does anyone really know CAAC's true air safety record ?
Information prior to 1968 is pretty much non-existent. Since then a quick look at http://aviation-safety.net/database/index.html yields the following hull losses for CAAC (all directorates). Not all involved fatalities.
Trident 6
An24 5
IL-14 2
IL-18, IL-62 and S360 1 each.
Lengthy research via 'spotter' sites containing aircraft type histories might bring some more to light, but I doubt the 20 years preceding 1968 were any safer.
Information prior to 1968 is pretty much non-existent. Since then a quick look at http://aviation-safety.net/database/index.html yields the following hull losses for CAAC (all directorates). Not all involved fatalities.
Trident 6
An24 5
IL-14 2
IL-18, IL-62 and S360 1 each.
Lengthy research via 'spotter' sites containing aircraft type histories might bring some more to light, but I doubt the 20 years preceding 1968 were any safer.
Last edited by PaperTiger; 20th Apr 2002 at 17:50.
Join Date: Aug 2001
Location: Australia
Posts: 72
Likes: 0
Received 0 Likes
on
0 Posts
Belgique
Three ponts. Your point a). is incorrect. You are required to maintain not lower than MDA until you intercept the normal approach PATH (3 degrees). Extend your 3degree slope back through your intended flight path and where they intercept is your descent point. Following your procedure an MDA of 1000' would give give you a required final of approximately 3miles. Way outside the circling visibility and area.
Your point b). according to ICAO doc 8168 Vol 1 fourth edition. ".........The Visual Manoeuvring area is "determined by drawing arcs centred on each runway threshold and joining those arcs with tangent lines....." No reference to ARP.
Your point c) is seemingly corrected later in your text. I would point out Jep ATC 4.1 pg 219 Flight Procedures (Doc 8168) ..........it is expected that the pilot will make an initial climbing turn towards the landing runway............
I could cite for you several areas where a "short turn" to the missed app heading will plant you on top of a hill. There should be no significant obstacles between you and the runway because up to the time that you decided to make the missed app you could see the runway (couldn't you). Ergo the safest way is to get you sh..t together as you head to the least threatening area.
GG
Three ponts. Your point a). is incorrect. You are required to maintain not lower than MDA until you intercept the normal approach PATH (3 degrees). Extend your 3degree slope back through your intended flight path and where they intercept is your descent point. Following your procedure an MDA of 1000' would give give you a required final of approximately 3miles. Way outside the circling visibility and area.
Your point b). according to ICAO doc 8168 Vol 1 fourth edition. ".........The Visual Manoeuvring area is "determined by drawing arcs centred on each runway threshold and joining those arcs with tangent lines....." No reference to ARP.
Your point c) is seemingly corrected later in your text. I would point out Jep ATC 4.1 pg 219 Flight Procedures (Doc 8168) ..........it is expected that the pilot will make an initial climbing turn towards the landing runway............
I could cite for you several areas where a "short turn" to the missed app heading will plant you on top of a hill. There should be no significant obstacles between you and the runway because up to the time that you decided to make the missed app you could see the runway (couldn't you). Ergo the safest way is to get you sh..t together as you head to the least threatening area.
GG
Last edited by grange.guzzler; 20th Apr 2002 at 23:54.
Join Date: Mar 2002
Location: India
Posts: 346
Likes: 0
Received 0 Likes
on
0 Posts
Paper Tiger:
Thanks for the link.
The point remains, though, that any statistics based on official information from China - particularly prior to the late 80's - is suspect.
In the wider context of the reliability or otherwise of China's statistics, it is interesting to note that the current GDP growth figures coming out of China are raising more questions than answers. Some things never change!
Thanks for the link.
The point remains, though, that any statistics based on official information from China - particularly prior to the late 80's - is suspect.
In the wider context of the reliability or otherwise of China's statistics, it is interesting to note that the current GDP growth figures coming out of China are raising more questions than answers. Some things never change!
grange.guzzler I have to stand in agreement with Belgique that the circling maneuver area takes no account of a 3 degree glide slope. If you fly out far enough to intercept it from a circling approach, you might hit something.
THIS time I'm with Capt. Guzzler. Hr doen't mean a three degree slope on the centreline he means a three degree descent on horizontal flight path be it curved or otherwise.
It basically means that you begin descent where ever a normal, three degree descent will have you rolling out on centreline and glideslope.
Now that I've given you one GG, I'm still at issue with your terminology. Visual VMC? If conditions are less than VMC, they are IMC, regardless of what you can or cannot see. Therefore any time you circle with less the 500ft vertical seperation from cloud, you are carrying out Visual circling inIMC conditions . If conditions weren't IMC, you wouldn't be bothering!
It basically means that you begin descent where ever a normal, three degree descent will have you rolling out on centreline and glideslope.
Now that I've given you one GG, I'm still at issue with your terminology. Visual VMC? If conditions are less than VMC, they are IMC, regardless of what you can or cannot see. Therefore any time you circle with less the 500ft vertical seperation from cloud, you are carrying out Visual circling inIMC conditions . If conditions weren't IMC, you wouldn't be bothering!
Join Date: Aug 2001
Location: alittle red dot...
Posts: 7
Likes: 0
Received 0 Likes
on
0 Posts
I find it appalling when I read the on-going threads about Air China's safety record. So what if what they claim is not true? An accident has happened and lives have been lost. Why don't we try to learn something from it?
Another observation is about the racial issue. If so many of you guys feel that asian airlines are 'second class', why are you still working for them? Could it be that you couldn't make the cut in the west and find yourself elevated in status (expat pilot) after going over to asia? Pls don't be hypocritcal...
Another observation is about the racial issue. If so many of you guys feel that asian airlines are 'second class', why are you still working for them? Could it be that you couldn't make the cut in the west and find yourself elevated in status (expat pilot) after going over to asia? Pls don't be hypocritcal...
Wizofoz Yes, you can descend on a 3 degree slope. Just stay inside the circling maneuver area above the circling MDA until on final.
And how do you set that up on the FMC, given that you will either have to level off on the ILS36, or fly high on the glideslope?
And how do you set that up on the FMC, given that you will either have to level off on the ILS36, or fly high on the glideslope?
Rather,
No, you don't have to be on final at MDA. It would be impossible. If you had to maintain, say,a 900 ft MDA inside a 2NM circling area, and take into account a turn radius, you would be at 900ft at 1.5nm, around 500ft high and in no position to make a stable approach. Descent can start anywhere on the projected 3 degree flight path.
As to the FMC, easy, you don't!! A centre line and trend vector can help (provided you have a good FMC update), but this is a VISUAL proceedure. Break out the old Eyeball mk1.
No, you don't have to be on final at MDA. It would be impossible. If you had to maintain, say,a 900 ft MDA inside a 2NM circling area, and take into account a turn radius, you would be at 900ft at 1.5nm, around 500ft high and in no position to make a stable approach. Descent can start anywhere on the projected 3 degree flight path.
As to the FMC, easy, you don't!! A centre line and trend vector can help (provided you have a good FMC update), but this is a VISUAL proceedure. Break out the old Eyeball mk1.
Wizofoz Show me the chapter and verse. I've been thoroughly brainwashed never to go below circling MDA until on final. [Chicken logo here]
Well, I might start descent on the turn to final if viz is good and/or I know the airport like the back of my hand.
Well, I might start descent on the turn to final if viz is good and/or I know the airport like the back of my hand.
Join Date: Mar 2000
Location: canada
Posts: 147
Likes: 0
Received 0 Likes
on
0 Posts
Hello Douglasflyer, re the circling appr rwy 18, please explain what those numbers mean. I'm not familiar. i.e. qfe ft/km 1680/3.7 qnh ft 1700. It's all quite confusing. What are they trying to tell us?
Thanks.
Also to any Lufthansa pilots-- what is your sop re the use of the FPA knob on non prec approaches (A-320) ? Do you use it prior to the FAF and if so, how far back??
Thanks.
Thanks.
Also to any Lufthansa pilots-- what is your sop re the use of the FPA knob on non prec approaches (A-320) ? Do you use it prior to the FAF and if so, how far back??
Thanks.
Join Date: Aug 2001
Location: alittle red dot...
Posts: 7
Likes: 0
Received 0 Likes
on
0 Posts
PaperTiger
I understand the implications of withholding the truth but don't you think there's a better time to do this? We were not in the cockpit so lets not second guess what happened. Remember the accident that happened not so long ago and the never ending thread about how inexperienced the Capt and the FO were..lets be sensitive please.
I understand the implications of withholding the truth but don't you think there's a better time to do this? We were not in the cockpit so lets not second guess what happened. Remember the accident that happened not so long ago and the never ending thread about how inexperienced the Capt and the FO were..lets be sensitive please.
Join Date: Mar 2001
Location: Wet Coast
Posts: 2,335
Likes: 0
Received 0 Likes
on
0 Posts
Any thread relating to an accident always seems to bring out at least one sanctimonious finger-wagger telling us what not to discuss and how insensitive etc. etc. we are all being.
Such sentiments have been eloquently refuted by more worthy individuals than I. Safety records, crew experience, airline SOPs, airport facilities and so on are all legitimate issues when speculating (yes !) as to what went wrong. Ethnic or cultural issues may be closer to the bone but absent patent racism, there may be some relevance there too.
The record of this board in dissecting accidents accurately and quickly speaks for itself I think. If you object to the tone of such discussions, maybe you should avoid them.
Such sentiments have been eloquently refuted by more worthy individuals than I. Safety records, crew experience, airline SOPs, airport facilities and so on are all legitimate issues when speculating (yes !) as to what went wrong. Ethnic or cultural issues may be closer to the bone but absent patent racism, there may be some relevance there too.
The record of this board in dissecting accidents accurately and quickly speaks for itself I think. If you object to the tone of such discussions, maybe you should avoid them.