 |
37000 Feet | Browse and search NASA's Aviation Safety Reporting System |
|
Flight crew of an medium large transport air carrier aircraft descended below assigned altitude in response to a TCASII RA. Visual sighting was made on what appeared to be the traffic.
| Attributes | |
| ACN | 253580 |
| Time | |
| Date | 199310 |
| Day | Tue |
| Local Time Of Day | 1801 To 2400 |
| Place | |
| Locale Reference | airport : las |
| State Reference | NV |
| Altitude | msl bound lower : 8500 msl bound upper : 9000 |
| Environment | |
| Flight Conditions | VMC |
| Light | Night |
| Aircraft 1 | |
| Controlling Facilities | tracon : las |
| Operator | common carrier : air carrier |
| Make Model Name | Medium Large Transport, Low Wing, 2 Turbojet Eng |
| Navigation In Use | Other Other |
| Flight Phase | descent other |
| Flight Plan | IFR |
| Person 1 | |
| Affiliation | company : air carrier |
| Function | flight crew : captain oversight : pic |
| Qualification | pilot : atp pilot : cfi |
| Experience | flight time last 90 days : 150 flight time total : 18000 flight time type : 3500 |
| ASRS Report | 253580 |
| Person 2 | |
| Affiliation | company : air carrier |
| Function | flight crew : first officer |
| Qualification | pilot : atp pilot : commercial |
| Experience | flight time last 90 days : 170 flight time total : 13000 flight time type : 4000 |
| ASRS Report | 253415 |
| Events | |
| Anomaly | altitude deviation : excursion from assigned altitude conflict : airborne less severe non adherence : clearance other anomaly other |
| Independent Detector | aircraft equipment other aircraft equipment : unspecified other flight crewa |
| Resolutory Action | flight crew : took evasive action |
| Consequence | Other |
| Miss Distance | horizontal : 15000 vertical : 300 |
| Supplementary | |
| Primary Problem | Flight Crew Human Performance |
| Air Traffic Incident | Pilot Deviation |
Narrative:
We were being vectored for ILS 25L at las. It appeared to be heavier traffic than normal because runway 25R was closed for construction. We were given a turn to 350 degree heading. TCASII gave a TA followed by an RA. Descend, descend now with a 2500 FPM descent on the ivsi. I disconnected the autoplt and descended to 8500 ft. We believe we had a visual on the traffic, but did not want to take a chance and a descent appeared to be the safe way to avoid the traffic. We did have some concern with a descent in this area because of the mountains. However, the descent stopped at 8500 with plenty of space below. It appears the TCASII worked well.
Original NASA ASRS Text
Title: FLC OF AN MLG ACR ACFT DSNDED BELOW ASSIGNED ALT IN RESPONSE TO A TCASII RA. VISUAL SIGHTING WAS MADE ON WHAT APPEARED TO BE THE TFC.
Narrative: WE WERE BEING VECTORED FOR ILS 25L AT LAS. IT APPEARED TO BE HEAVIER TFC THAN NORMAL BECAUSE RWY 25R WAS CLOSED FOR CONSTRUCTION. WE WERE GIVEN A TURN TO 350 DEG HDG. TCASII GAVE A TA FOLLOWED BY AN RA. DSND, DSND NOW WITH A 2500 FPM DSCNT ON THE IVSI. I DISCONNECTED THE AUTOPLT AND DSNDED TO 8500 FT. WE BELIEVE WE HAD A VISUAL ON THE TFC, BUT DID NOT WANT TO TAKE A CHANCE AND A DSCNT APPEARED TO BE THE SAFE WAY TO AVOID THE TFC. WE DID HAVE SOME CONCERN WITH A DSCNT IN THIS AREA BECAUSE OF THE MOUNTAINS. HOWEVER, THE DSCNT STOPPED AT 8500 WITH PLENTY OF SPACE BELOW. IT APPEARS THE TCASII WORKED WELL.
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.