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Fat TRACON controller reported two aircraft drifted into areas with mvas above their assigned altitude due to strong winds aloft.
| Attributes | |
| ACN | 1437388 |
| Time | |
| Date | 201704 |
| Local Time Of Day | 1201-1800 |
| Place | |
| Locale Reference | FAT.TRACON |
| State Reference | CA |
| Environment | |
| Light | Daylight |
| Aircraft 1 | |
| Make Model Name | Small Transport |
| Operating Under FAR Part | Part 135 |
| Flight Phase | Initial Approach |
| Route In Use | Vectors |
| Flight Plan | IFR |
| Person 1 | |
| Function | Approach |
| Qualification | Air Traffic Control Fully Certified |
| Experience | Air Traffic Control Time Certified In Pos 1 (yrs) 1 |
| Events | |
| Anomaly | ATC Issue All Types Deviation - Procedural Published Material / Policy Inflight Event / Encounter CFTT / CFIT |
Narrative:
On vector for a 29R ILS approach; aircraft X was issued heading 110 for the downwind at 3000 ft. Approaching a 3400 MVA; aircraft X was instructed to turn to 150; preparing for the base turn. Aircraft X did not make his turn quickly; but delayed which allowed him to turn wide. I instructed him to continue to a heading of 180; and climb to 3500 to clear the MVA but not in time to prevent his fusion bubble from coming into contact with the MVA line; which it touched while he was at 3100 ft. Winds aloft had made multiple aircraft drift easterly; which I had not considered until another aircraft on vector to the ILS had a similar situation. [The aircraft] was descended to 4000; over a 3400 MVA. He was instructed to fly a heading of 120; vector to the final approach and sequence; which paralleled a 4700 ft MVA. After doing a few other things; I noticed he had drifted easterly; and issued him a heading of 150 to gain distance from the higher MVA; but not in time to prevent his fusion bubble from touching the MVA line; which it did at 4400 ft. Further traffic was afforded much larger lateral 'buffers' from higher mvas to allow drift due to winds aloft. This was a learning experience for me. I will be much more aware of winds aloft in the future; and compensate accordingly. If winds aloft are a concern; I will stop aircraft descents above the adjacent MVA if that MVA is higher. Also; I will compensate wide turns for winds aloft by allowing more time for pilot compliance.
Original NASA ASRS Text
Title: FAT TRACON Controller reported two aircraft drifted into areas with MVAs above their assigned altitude due to strong winds aloft.
Narrative: On vector for a 29R ILS approach; Aircraft X was issued heading 110 for the downwind at 3000 ft. Approaching a 3400 MVA; Aircraft X was instructed to turn to 150; preparing for the base turn. Aircraft X did not make his turn quickly; but delayed which allowed him to turn wide. I instructed him to continue to a heading of 180; and climb to 3500 to clear the MVA but not in time to prevent his fusion bubble from coming into contact with the MVA line; which it touched while he was at 3100 ft. Winds aloft had made multiple aircraft drift easterly; which I had not considered until another aircraft on vector to the ILS had a similar situation. [The aircraft] was descended to 4000; over a 3400 MVA. He was instructed to fly a heading of 120; vector to the final approach and sequence; which paralleled a 4700 ft MVA. After doing a few other things; I noticed he had drifted easterly; and issued him a heading of 150 to gain distance from the higher MVA; but not in time to prevent his fusion bubble from touching the MVA line; which it did at 4400 ft. Further traffic was afforded much larger lateral 'buffers' from higher MVAs to allow drift due to winds aloft. This was a learning experience for me. I will be much more aware of winds aloft in the future; and compensate accordingly. If winds aloft are a concern; I will stop aircraft descents above the adjacent MVA if that MVA is higher. Also; I will compensate wide turns for winds aloft by allowing more time for pilot compliance.
Data retrieved from NASA's ASRS site 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.