Narrative:

This is the second time in 3 days that this type of situation developed. Staggered ILS approaches with crda (converging runway display aid) to runway 27. Strong winds out of the southwest. We were not doing simo's because of an equipment failure just prior to this session. The wind was making the aircraft from the east slow really early and the tail wind was pushing the aircraft from the west. I was having to use altitude to get into the gap set by the other side and try to use some speed until the wind was no longer on the tail. Then I was descending and or clearing the aircraft once separation was established. Compression and various different aircraft types made it an even more difficult process. The aircraft would slide into the base turn and I had to estimate how much based on type aircraft and pilot ability while getting into a gap of 2 aircraft that was slowed and into the wind. There were a couple of close situations: 1. One keeping a commuter in trail of a heavy while waiting to loose some speed and also hitting a set gap of slowed aircraft on the other final. I had to withhold a clearance until a couple miles outside of the marker until I could get enough speed off the commuter.2. Keeping a boeing 727 up at a higher altitude and trying to loose speed to stagger on a rapidly slowing rj on the other ILS. I turned the boeing out to get him lower and then turned him back in once I had spacing. The tower had reported seeing them at 5 miles so I expected the visual as he approached the 5 miles and did not see the field; I broke him out to the west to re-sequence.3. Compression of the stagger of a boeing 727 on a heavy jet on the other final. The boeing had been broke out earlier; so I informed the other controller to break the heavy out so the boeing could land this time. I heard him issue the turn to the heavy; so I cleared my boeing and then switched him to the tower. The other controller used the wrong call sign and broke the wrong heavy out. Once he noticed his mistake; he then broke the other one out. 4. A regional jet was being put into a gap ahead of one of my aircraft at the step down fix. The regional jet had slowed on is own to 170 KTS or less. I had to withhold my clearance until the other controller could speed the rj up to 180 KTS which was not going to be enough. We were not doing simo's because the glideslope went out on runway 18R. This is the 3rd time in 3 days that we have lost a part of an ILS approach during a push. Two times we have lost the DME on 18L and now the GS on 18R. Along with the consistent loss of or near loss of frequencies these are just a couple contributing factors of these very intense situations. I would say again; we should be doing simo's. But I guess 1st we would have to keep our ILS systems in full working order to do this. Doing crda and staggered ilss is not a good idea either. With the difficult wind and the equipment issues; we must find a way to reduce the work load on final. I have talked to many controllers over the last few days and we all agree since we run staggers so rarely now; we just do not do it well. So I think since we can't rely on the equipment to stay up; we need to find a way to keep our skills up on staggered ilss. The toughest thing seems to be working with the person on the other side. Not any one particular person; but if the two persons have a really different style; and we do not get much practice at it; the complications seem to arise rapidly. One controller technique is to slow the picture down early and keep everything at a consistent speed and consistent gap. That is a good technique and can be applied to the side of final going into the wind. But if they are 1 mile late and into the wind; making up ground is very difficult. Other controllers like to keep a little speed on the aircraft to get into the gap and to make sure they are in the middle of the gap or slightly in the back and moving to the middle. This technique is also effectiveunless you have a 40 KT tailwind on your base legs. You then have to slow to 170 KTS or less; but that is still showing 210 across the ground; the other side has slowed the picture down and now when they turn into the wind the 190 KT base leg or 170 KT dogleg to final is showing 160 or less across the ground. These are situations we adapt to many times in our career; but when we seem to only do it 4 or 5 times in 6 months it sometimes feels like a lost art.

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Original NASA ASRS Text

Title: M03 Controller provided a detailed account of a very complex CRDA operations event; indicating both CRDA and simultaneous procedures are hampered when all the required equipment is not available; adding that the wind and lack of operations familiarity contributed to the complexity.

Narrative: This is the second time in 3 days that this type of situation developed. Staggered ILS approaches with CRDA (converging runway display aid) to Runway 27. Strong winds out of the southwest. We were not doing SIMO's because of an equipment failure just prior to this session. The wind was making the aircraft from the east slow really early and the tail wind was pushing the aircraft from the west. I was having to use altitude to get into the gap set by the other side and try to use some speed until the wind was no longer on the tail. Then I was descending and or clearing the aircraft once separation was established. Compression and various different aircraft types made it an even more difficult process. The aircraft would slide into the base turn and I had to estimate how much based on type aircraft and pilot ability while getting into a gap of 2 aircraft that was slowed and into the wind. There were a couple of close situations: 1. One keeping a commuter in trail of a heavy while waiting to loose some speed and also hitting a set gap of slowed aircraft on the other final. I had to withhold a clearance until a couple miles outside of the marker until I could get enough speed off the commuter.2. Keeping a Boeing 727 up at a higher altitude and trying to loose speed to stagger on a rapidly slowing RJ on the other ILS. I turned the Boeing out to get him lower and then turned him back in once I had spacing. The Tower had reported seeing them at 5 miles so I expected the visual as he approached the 5 miles and did not see the field; I broke him out to the west to re-sequence.3. Compression of the stagger of a Boeing 727 on a heavy jet on the other final. The Boeing had been broke out earlier; so I informed the other controller to break the heavy out so the Boeing could land this time. I heard him issue the turn to the heavy; so I cleared my Boeing and then switched him to the Tower. The other controller used the wrong call sign and broke the wrong heavy out. Once he noticed his mistake; he then broke the other one out. 4. A regional jet was being put into a gap ahead of one of my aircraft at the step down fix. The regional jet had slowed on is own to 170 KTS or less. I had to withhold my clearance until the other controller could speed the RJ up to 180 KTS which was not going to be enough. We were not doing SIMO's because the glideslope went out on Runway 18R. This is the 3rd time in 3 days that we have lost a part of an ILS approach during a push. Two times we have lost the DME on 18L and now the GS on 18R. Along with the consistent loss of or near loss of frequencies these are just a couple contributing factors of these very intense situations. I would say again; we should be doing SIMO's. But I guess 1st we would have to keep our ILS systems in full working order to do this. Doing CRDA and staggered ILSs is not a good idea either. With the difficult wind and the equipment issues; we must find a way to reduce the work load on final. I have talked to many controllers over the last few days and we all agree since we run staggers so rarely now; we just do not do it well. So I think since we can't rely on the equipment to stay up; we need to find a way to keep our skills up on staggered ILSs. The toughest thing seems to be working with the person on the other side. Not any one particular person; but if the two persons have a really different style; and we do not get much practice at it; the complications seem to arise rapidly. One controller technique is to slow the picture down early and keep everything at a consistent speed and consistent gap. That is a good technique and can be applied to the side of final going into the wind. But if they are 1 mile late and into the wind; making up ground is very difficult. Other controllers like to keep a little speed on the aircraft to get into the gap and to make sure they are in the middle of the gap or slightly in the back and moving to the middle. This technique is also effectiveunless you have a 40 KT tailwind on your base legs. You then have to slow to 170 KTS or less; but that is still showing 210 across the ground; the other side has slowed the picture down and now when they turn into the wind the 190 KT base leg or 170 KT dogleg to final is showing 160 or less across the ground. These are situations we adapt to many times in our career; but when we seem to only do it 4 or 5 times in 6 months it sometimes feels like a lost art.

Data retrieved from NASA's ASRS site as of April 2012 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.