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Large transport air carrier flight crew acknowledged for altitude descent from FL350 to FL310. ARTCC controller challenged flight crew as aircraft descended through FL336, denying descent clearance was issued. Controller reassigned FL350. Reporter would feel better if controller would acknowledge error.
| Attributes | |
| ACN | 395089 |
| Time | |
| Date | 199802 |
| Day | Fri |
| Local Time Of Day | 1801 To 2400 |
| Place | |
| Locale Reference | atc facility : vhp |
| State Reference | IN |
| Altitude | msl bound lower : 33600 msl bound upper : 35000 |
| Environment | |
| Flight Conditions | VMC |
| Light | Daylight |
| Aircraft 1 | |
| Controlling Facilities | artcc : zid |
| Operator | common carrier : air carrier |
| Make Model Name | Commercial Fixed Wing |
| Operating Under FAR Part | Part 121 |
| Navigation In Use | Other |
| Flight Phase | descent other |
| Route In Use | enroute other |
| Flight Plan | IFR |
| Aircraft 2 | |
| Make Model Name | Any Unknown or Unlisted Aircraft Manufacturer |
| Operating Under FAR Part | other : unknown |
| Flight Phase | cruise other |
| Flight Plan | IFR |
| Person 1 | |
| Affiliation | company : air carrier |
| Function | flight crew : first officer |
| Qualification | pilot : atp |
| Experience | flight time last 90 days : 240 flight time total : 5000 flight time type : 1200 |
| ASRS Report | 395089 |
| Person 2 | |
| Affiliation | company : air carrier |
| Function | flight crew : captain oversight : pic |
| Qualification | pilot : atp |
| Events | |
| Anomaly | conflict : airborne less severe non adherence : published procedure non adherence : required legal separation other anomaly other |
| Independent Detector | aircraft equipment other aircraft equipment : unspecified other controllera |
| Resolutory Action | flight crew : returned to intended course or assigned course flight crew : took evasive action other |
| Consequence | Other |
| Miss Distance | horizontal : 0 vertical : 1000 |
| Supplementary | |
| Primary Problem | ATC Human Performance |
| Air Traffic Incident | Operational Error |
Narrative:
We were 50 mi southeast of ind VOR at FL350. ZID issued us a clearance of 'descend, maintain FL310, give me at least 2000 FPM down.' the captain set FL310 in the altitude alert window and I confirmed FL310 by pointing at it. I set the vertical speed to -2000 on the MCP and the autoplt began the descent. Out of FL336, center said 'air carrier XXX, you aren't descending are you?' the captain replied, 'yes, to FL310.' the controller then issued an immediate climb back to FL350. Soon after, we got a TCASII 'traffic' alert. During our climb we saw an airplane pass directly under us at FL330. When we asked the controller about the incident, he denied giving us the descent clearance and told us he didn't have time to discuss it. I believe the controller was very busy and forgot that he gave us descent clearance and realized it when he saw a conflict. We all make mistakes and thank goodness for TCASII, but we must also admit the mistake so we all feel better. This controller just wanted to brush over the incident and change us over to the next frequency.
Original NASA ASRS Text
Title: LGT ACR FLC ACKNOWLEDGED FOR ALT DSCNT FROM FL350 TO FL310. ARTCC CTLR CHALLENGED FLC AS ACFT DSNDED THROUGH FL336, DENYING DSCNT CLRNC WAS ISSUED. CTLR REASSIGNED FL350. RPTR WOULD FEEL BETTER IF CTLR WOULD ACKNOWLEDGE ERROR.
Narrative: WE WERE 50 MI SE OF IND VOR AT FL350. ZID ISSUED US A CLRNC OF 'DSND, MAINTAIN FL310, GIVE ME AT LEAST 2000 FPM DOWN.' THE CAPT SET FL310 IN THE ALT ALERT WINDOW AND I CONFIRMED FL310 BY POINTING AT IT. I SET THE VERT SPD TO -2000 ON THE MCP AND THE AUTOPLT BEGAN THE DSCNT. OUT OF FL336, CTR SAID 'ACR XXX, YOU AREN'T DSNDING ARE YOU?' THE CAPT REPLIED, 'YES, TO FL310.' THE CTLR THEN ISSUED AN IMMEDIATE CLB BACK TO FL350. SOON AFTER, WE GOT A TCASII 'TFC' ALERT. DURING OUR CLB WE SAW AN AIRPLANE PASS DIRECTLY UNDER US AT FL330. WHEN WE ASKED THE CTLR ABOUT THE INCIDENT, HE DENIED GIVING US THE DSCNT CLRNC AND TOLD US HE DIDN'T HAVE TIME TO DISCUSS IT. I BELIEVE THE CTLR WAS VERY BUSY AND FORGOT THAT HE GAVE US DSCNT CLRNC AND REALIZED IT WHEN HE SAW A CONFLICT. WE ALL MAKE MISTAKES AND THANK GOODNESS FOR TCASII, BUT WE MUST ALSO ADMIT THE MISTAKE SO WE ALL FEEL BETTER. THIS CTLR JUST WANTED TO BRUSH OVER THE INCIDENT AND CHANGE US OVER TO THE NEXT FREQ.
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.