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C90 controller voiced concern regarding the 7000 ft crossing restriction at grabl during triple simultaneous approaches; claiming aircraft are crossing grabl low resulting in loss of separation events.
| Attributes | |
| ACN | 847664 |
| Time | |
| Date | 200908 |
| Local Time Of Day | 0601-1200 |
| Place | |
| Locale Reference | ORD.Airport |
| State Reference | IL |
| Aircraft 1 | |
| Make Model Name | No Aircraft |
| Person 1 | |
| Function | Approach |
| Qualification | Air Traffic Control Fully Certified |
| Experience | Air Traffic Control Military 3 Air Traffic Control Radar 21 |
| Events | |
| Anomaly | Deviation - Altitude Crossing Restriction Not Met Deviation - Procedural Published Material / Policy Deviation - Procedural Clearance |
Narrative:
Ord arrival configuration is west flow; runways 27R/27L/28 triple simultaneous approaches. Numerous aircraft issued the ILS 27L at ord; with an approach clearance to cross grabl at 7000 then cleared ILS; are crossing grabl 300 to 400 feet below the 7000 ft crossing restriction. When 27R and 28 are utilizing the simultaneous ILS; the early descent at grabl has resulted in numerous operational errors. C90 management has attempted to fix the situation with a bandaid. Runway 27R and 28 are now forced to turn base leg at least 5 miles further out than usual in order to protect for the early descent. A significant impact by this hopefully temporary fix is to the north sat sector. Southbound aircraft must now either: descend to 3000 and share airspace with northbound aircraft at 3000 or southbound aircraft be vectored at least 35 miles east of ord versus at least 25 miles east of ord.
Original NASA ASRS Text
Title: C90 Controller voiced concern regarding the 7000 FT crossing restriction at GRABL during triple simultaneous approaches; claiming aircraft are crossing GRABL low resulting in loss of separation events.
Narrative: ORD Arrival configuration is west flow; Runways 27R/27L/28 triple simultaneous approaches. Numerous aircraft issued the ILS 27L at ORD; with an approach clearance to cross GRABL at 7000 then cleared ILS; are crossing GRABL 300 to 400 feet below the 7000 FT crossing restriction. When 27R and 28 are utilizing the simultaneous ILS; the early descent at GRABL has resulted in numerous operational errors. C90 Management has attempted to fix the situation with a bandaid. Runway 27R and 28 are now forced to turn base leg at least 5 miles further out than usual in order to protect for the early descent. A significant impact by this hopefully temporary fix is to the North SAT Sector. Southbound aircraft must now either: descend to 3000 and share airspace with northbound aircraft at 3000 or southbound aircraft be vectored at least 35 miles east of ORD versus at least 25 miles east of ORD.
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.