 |
37000 Feet | Browse and search NASA's Aviation Safety Reporting System |
|
ZID controller experienced loss of separation at FL270 when 2 aircraft were having difficulty with altitude assignments and readbacks.
| Attributes | |
| ACN | 702247 |
| Time | |
| Date | 200606 |
| Local Time Of Day | 0601 To 1200 |
| Place | |
| Locale Reference | atc facility : zid.artcc |
| State Reference | TN |
| Altitude | msl single value : 27000 |
| Environment | |
| Flight Conditions | VMC |
| Light | Daylight |
| Aircraft 1 | |
| Controlling Facilities | artcc : zid.artcc |
| Operator | common carrier : air carrier |
| Make Model Name | Any Unknown or Unlisted Aircraft Manufacturer |
| Operating Under FAR Part | Part 121 |
| Flight Phase | climbout : intermediate altitude descent : intermediate altitude |
| Flight Plan | IFR |
| Aircraft 2 | |
| Controlling Facilities | artcc : zid.artcc |
| Operator | common carrier : air carrier |
| Person 1 | |
| Affiliation | government : faa |
| Function | controller : radar |
| Qualification | controller : radar |
| Experience | controller limited radar : 2 controller time certified in position2 : 9 |
| ASRS Report | 702247 |
| Person 2 | |
| Affiliation | company : air carrier |
| Function | flight crew : captain oversight : pic |
| Events | |
| Anomaly | conflict : airborne less severe non adherence : required legal separation |
| Independent Detector | other controllera |
| Resolutory Action | controller : issued new clearance flight crew : took evasive action |
| Consequence | faa : investigated |
| Miss Distance | horizontal : 28800 vertical : 800 |
| Supplementary | |
| Problem Areas | ATC Human Performance |
| Primary Problem | ATC Human Performance |
Narrative:
Aircraft X was issued FL280. Aircraft X was issued FL280 again. Aircraft Y was issued FL270. Aircraft X stole aircraft Y's clearance with an unclr call sign on readback. Aircraft X was seen leaving FL280. (I thought he was leveling at FL280.) aircraft X was told to maintain FL280; aircraft X did not. Instead aircraft X said he would maintain FL270. Aircraft Y was issued FL260. Aircraft X stole the clearance. Aircraft X was told 'negative; maintain FL270.' again; aircraft X did not follow his clearance; saying he would maintain FL260. Aircraft X was told 'negative; maintain FL270.' separation was lost.
Original NASA ASRS Text
Title: ZID CTLR EXPERIENCED LOSS OF SEPARATION AT FL270 WHEN 2 ACFT WERE HAVING DIFFICULTY WITH ALT ASSIGNMENTS AND READBACKS.
Narrative: ACFT X WAS ISSUED FL280. ACFT X WAS ISSUED FL280 AGAIN. ACFT Y WAS ISSUED FL270. ACFT X STOLE ACFT Y'S CLRNC WITH AN UNCLR CALL SIGN ON READBACK. ACFT X WAS SEEN LEAVING FL280. (I THOUGHT HE WAS LEVELING AT FL280.) ACFT X WAS TOLD TO MAINTAIN FL280; ACFT X DID NOT. INSTEAD ACFT X SAID HE WOULD MAINTAIN FL270. ACFT Y WAS ISSUED FL260. ACFT X STOLE THE CLRNC. ACFT X WAS TOLD 'NEGATIVE; MAINTAIN FL270.' AGAIN; ACFT X DID NOT FOLLOW HIS CLRNC; SAYING HE WOULD MAINTAIN FL260. ACFT X WAS TOLD 'NEGATIVE; MAINTAIN FL270.' SEPARATION WAS LOST.
Data retrieved from NASA's ASRS site as of January 2009 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.