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Separation lost by an ind departure controller when an E145 flight crew depart and overtake a DC9, both on runway heading climbing to 5000 ft.
| Attributes | |
| ACN | 617633 |
| Time | |
| Date | 200405 |
| Day | Sat |
| Local Time Of Day | 1201 To 1800 |
| Place | |
| Locale Reference | airport : ind.airport |
| State Reference | IN |
| Altitude | msl single value : 4000 |
| Environment | |
| Flight Conditions | Marginal |
| Light | Daylight |
| Aircraft 1 | |
| Controlling Facilities | tracon : ind.tracon |
| Operator | common carrier : air carrier |
| Make Model Name | DC-9 Undifferentiated or Other Model |
| Operating Under FAR Part | Part 121 |
| Flight Phase | climbout : intermediate altitude |
| Route In Use | departure : on vectors |
| Flight Plan | IFR |
| Aircraft 2 | |
| Controlling Facilities | tracon : ind.tracon |
| Operator | common carrier : air carrier |
| Make Model Name | EMB ERJ 145 ER&LR |
| Operating Under FAR Part | Part 121 |
| Flight Phase | climbout : intermediate altitude |
| Route In Use | departure : on vectors |
| Flight Plan | IFR |
| Person 1 | |
| Affiliation | government : faa |
| Function | controller : departure |
| Qualification | controller : radar pilot : instrument |
| Experience | controller radar : 6 controller time certified in position1 : 1 flight time total : 300 |
| ASRS Report | 617633 |
| Person 2 | |
| Affiliation | company : air carrier |
| Function | flight crew : captain oversight : pic |
| Events | |
| Anomaly | conflict : airborne critical non adherence : required legal separation non adherence : published procedure |
| Independent Detector | atc equipment other atc equipment : radar/mode c other controllera |
| Resolutory Action | none taken : insufficient time |
| Miss Distance | horizontal : 6000 vertical : 500 |
| Supplementary | |
| Problem Areas | Aircraft Flight Crew Human Performance ATC Human Performance |
| Primary Problem | ATC Human Performance |
| Air Traffic Incident | Operational Error |
Narrative:
Air carrier X departed ind on runway heading and climbing to 5000 ft. Air carrier Y departed ind, same runway on runway heading to 5000 ft. Runway separation was ensured. Separation was lost due to air carrier Y's and air carrier X's differing performance. Even though both aircraft were turbojets with similar performance characteristics, air carrier X for some unknown reason was climbing at an unusually slow rate and ground speed. Air carrier Y for an unknown reason was climbing at an unusually high rate and airspeed. This led to an overtake situation between the 2 aircraft. The WX was relatively cool for the time of yr (50-60 degrees F) and it wasn't very humid. Air carrier Y may have been on a maintenance flight and been very lightly loaded and air carrier X may have been unusually heavy. This may have led to the performance discrepancies. As ATC controllers, we need to use our best judgement given each situation based on what we know. We have no way of knowing if an aircraft will make an unusually high performance takeoff or will have unusual performance characteristics.
Original NASA ASRS Text
Title: SEPARATION LOST BY AN IND DEP CTLR WHEN AN E145 FLT CREW DEPART AND OVERTAKE A DC9, BOTH ON RWY HDG CLBING TO 5000 FT.
Narrative: ACR X DEPARTED IND ON RWY HDG AND CLBING TO 5000 FT. ACR Y DEPARTED IND, SAME RWY ON RWY HDG TO 5000 FT. RWY SEPARATION WAS ENSURED. SEPARATION WAS LOST DUE TO ACR Y'S AND ACR X'S DIFFERING PERFORMANCE. EVEN THOUGH BOTH ACFT WERE TURBOJETS WITH SIMILAR PERFORMANCE CHARACTERISTICS, ACR X FOR SOME UNKNOWN REASON WAS CLBING AT AN UNUSUALLY SLOW RATE AND GND SPD. ACR Y FOR AN UNKNOWN REASON WAS CLBING AT AN UNUSUALLY HIGH RATE AND AIRSPD. THIS LED TO AN OVERTAKE SIT BTWN THE 2 ACFT. THE WX WAS RELATIVELY COOL FOR THE TIME OF YR (50-60 DEGS F) AND IT WASN'T VERY HUMID. ACR Y MAY HAVE BEEN ON A MAINT FLT AND BEEN VERY LIGHTLY LOADED AND ACR X MAY HAVE BEEN UNUSUALLY HVY. THIS MAY HAVE LED TO THE PERFORMANCE DISCREPANCIES. AS ATC CTLRS, WE NEED TO USE OUR BEST JUDGEMENT GIVEN EACH SIT BASED ON WHAT WE KNOW. WE HAVE NO WAY OF KNOWING IF AN ACFT WILL MAKE AN UNUSUALLY HIGH PERFORMANCE TKOF OR WILL HAVE UNUSUAL PERFORMANCE CHARACTERISTICS.
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.