 |
37000 Feet | Browse and search NASA's Aviation Safety Reporting System |
|
Medium large transport receives TA and sights traffic on TCASII but no visual sighting. ATC clears to descend. Exceeds 250 KTS.
| Attributes | |
| ACN | 245883 |
| Time | |
| Date | 199307 |
| Day | Fri |
| Local Time Of Day | 1201 To 1800 |
| Place | |
| Locale Reference | atc facility : ord |
| State Reference | IL |
| Altitude | msl bound lower : 9000 msl bound upper : 10000 |
| Environment | |
| Flight Conditions | VMC |
| Light | Daylight |
| Aircraft 1 | |
| Controlling Facilities | tower : mxp |
| Operator | common carrier : air carrier |
| Make Model Name | Medium Large Transport, Low Wing, 2 Turbojet Eng |
| Flight Phase | cruise other descent other |
| Route In Use | enroute : direct enroute airway : zau |
| Flight Plan | IFR |
| Aircraft 2 | |
| Make Model Name | Any Unknown or Unlisted Aircraft Manufacturer |
| Flight Phase | cruise other |
| Flight Plan | VFR |
| Person 1 | |
| Affiliation | company : air carrier |
| Function | flight crew : captain oversight : pic |
| Qualification | pilot : atp pilot : flight engineer |
| Experience | flight time last 90 days : 150 flight time total : 10000 |
| ASRS Report | 245883 |
| Person 2 | |
| Affiliation | company : air carrier |
| Function | flight crew : first officer |
| Qualification | pilot : commercial pilot : instrument pilot : atp |
| Events | |
| Anomaly | non adherence : far other anomaly other anomaly other |
| Independent Detector | aircraft equipment other aircraft equipment : unspecified other controllera |
| Resolutory Action | controller : issued new clearance |
| Consequence | Other |
| Miss Distance | horizontal : 18000 vertical : 400 |
| Supplementary | |
| Air Traffic Incident | Pilot Deviation other |
Narrative:
We were proceeding direct to ord VOR at 10000 ft. ATC issued a TA 'VFR traffic, 1 O'clock, 10500 ft, unverified.' we had no visual contact with the traffic but TCASII showed a target 3-5 NM and 400 ft (10400 ft) and converging. I was about to ask ATC for a vector to avoid the traffic when ATC cleared us to descend to 9000 ft because of the close proximity of the traffic shown on the TCASII and still no visual contact. I immediately commenced the descent to avoid a possible TCASII 'RA.' during the descent 250 KTS was exceeded. The airspeed was corrected to 250 KTS when we were level at 9000 ft and the traffic no longer a factor.
Original NASA ASRS Text
Title: MLG RECEIVES TA AND SIGHTS TFC ON TCASII BUT NO VISUAL SIGHTING. ATC CLRS TO DSND. EXCEEDS 250 KTS.
Narrative: WE WERE PROCEEDING DIRECT TO ORD VOR AT 10000 FT. ATC ISSUED A TA 'VFR TFC, 1 O'CLOCK, 10500 FT, UNVERIFIED.' WE HAD NO VISUAL CONTACT WITH THE TFC BUT TCASII SHOWED A TARGET 3-5 NM AND 400 FT (10400 FT) AND CONVERGING. I WAS ABOUT TO ASK ATC FOR A VECTOR TO AVOID THE TFC WHEN ATC CLRED US TO DSND TO 9000 FT BECAUSE OF THE CLOSE PROX OF THE TFC SHOWN ON THE TCASII AND STILL NO VISUAL CONTACT. I IMMEDIATELY COMMENCED THE DSCNT TO AVOID A POSSIBLE TCASII 'RA.' DURING THE DSCNT 250 KTS WAS EXCEEDED. THE AIRSPD WAS CORRECTED TO 250 KTS WHEN WE WERE LEVEL AT 9000 FT AND THE TFC NO LONGER A FACTOR.
Data retrieved from NASA's ASRS site as of July 2007 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.