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Less than standard separation when atl tower clears medium large transport to climb through an altitude occupied by an small aircraft.
| Attributes | |
| ACN | 141331 |
| Time | |
| Date | 199003 |
| Day | Wed |
| Local Time Of Day | 1201 To 1800 |
| Place | |
| Locale Reference | airport : atl |
| State Reference | GA |
| Altitude | msl bound lower : 4000 msl bound upper : 4700 |
| Environment | |
| Flight Conditions | VMC |
| Light | Daylight |
| Aircraft 1 | |
| Controlling Facilities | tracon : atl tower : atl tracon : crp |
| Operator | common carrier : air carrier |
| Make Model Name | Medium Large Transport, Low Wing, 2 Turbojet Eng |
| Navigation In Use | Other |
| Flight Phase | climbout : intermediate altitude |
| Route In Use | departure sid : sid |
| Flight Plan | IFR |
| Aircraft 2 | |
| Make Model Name | Small Aircraft, High Wing, 1 Eng, Fixed Gear |
| Flight Phase | cruise other |
| Person 1 | |
| Affiliation | company : air carrier |
| Function | flight crew : first officer |
| Qualification | pilot : atp |
| Experience | flight time last 90 days : 220 flight time total : 5000 flight time type : 1500 |
| ASRS Report | 141331 |
| Person 2 | |
| Affiliation | company : air carrier |
| Function | flight crew : captain oversight : pic |
| Qualification | pilot : atp |
| Experience | flight time last 90 days : 90 flight time total : 13000 flight time type : 70 |
| ASRS Report | 141982 |
| Events | |
| Anomaly | conflict : airborne less severe non adherence : required legal separation |
| Independent Detector | other controllera other flight crewa |
| Resolutory Action | controller : issued new clearance flight crew : took evasive action other |
| Consequence | Other |
| Miss Distance | horizontal : 1500 |
| Supplementary | |
| Primary Problem | ATC Human Performance |
| Air Traffic Incident | Operational Error |
Narrative:
Clearance was atlanta 1 departure to 10000 ft. Tower cleared us for takeoff from 9L with a heading of 095 degree. First officer was flying. Takeoff and climbout was routine. Tower handed us off to departure. Captain attempted contact at approximately 3000 ft MSL with no reply. Tried again at approximately 4000 ft MSL. At the same time ATC replied and told us to level at 4000 ft, we were already at 4500 ft. I had already sighted traffic off to the right in a right-hand turn away from us. Small aircraft Y was probably no closer than 1500 ft-2000 ft. Upon receiving clearance to level at 4000 ft we were at 4500 ft and probably topped out at approximately 4700 ft before beginning descent. Before we could descend significantly, ATC again cleared us to the original altitude of 10000 ft. No avoidance maneuver was necessary. Telephone call by captain to ATC atl (confirmed by tapes) showed that ATC had neglected to give us a hold-down altitude when they were aware of the light aircraft (also under ATC control).
Original NASA ASRS Text
Title: LESS THAN STANDARD SEPARATION WHEN ATL TWR CLEARS MLG TO CLIMB THROUGH AN ALT OCCUPIED BY AN SMA.
Narrative: CLRNC WAS ATLANTA 1 DEP TO 10000 FT. TWR CLRED US FOR TKOF FROM 9L WITH A HDG OF 095 DEG. F/O WAS FLYING. TKOF AND CLIMBOUT WAS ROUTINE. TWR HANDED US OFF TO DEP. CAPT ATTEMPTED CONTACT AT APPROX 3000 FT MSL WITH NO REPLY. TRIED AGAIN AT APPROX 4000 FT MSL. AT THE SAME TIME ATC REPLIED AND TOLD US TO LEVEL AT 4000 FT, WE WERE ALREADY AT 4500 FT. I HAD ALREADY SIGHTED TFC OFF TO THE RIGHT IN A RIGHT-HAND TURN AWAY FROM US. SMA Y WAS PROBABLY NO CLOSER THAN 1500 FT-2000 FT. UPON RECEIVING CLRNC TO LEVEL AT 4000 FT WE WERE AT 4500 FT AND PROBABLY TOPPED OUT AT APPROX 4700 FT BEFORE BEGINNING DSCNT. BEFORE WE COULD DSND SIGNIFICANTLY, ATC AGAIN CLRED US TO THE ORIGINAL ALT OF 10000 FT. NO AVOIDANCE MANEUVER WAS NECESSARY. TELEPHONE CALL BY CAPT TO ATC ATL (CONFIRMED BY TAPES) SHOWED THAT ATC HAD NEGLECTED TO GIVE US A HOLD-DOWN ALT WHEN THEY WERE AWARE OF THE LIGHT ACFT (ALSO UNDER ATC CTL).
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.