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Air carrier X takeoff on occupied runway had less than standard separation from air carrier Y. System error. Night operation.
| Attributes | |
| ACN | 297803 |
| Time | |
| Date | 199502 |
| Day | Thu |
| Local Time Of Day | 1801 To 2400 |
| Place | |
| Locale Reference | atc facility : dtw |
| State Reference | MI |
| Altitude | agl bound lower : 0 agl bound upper : 0 |
| Environment | |
| Flight Conditions | VMC |
| Light | Night |
| Aircraft 1 | |
| Operator | common carrier : air carrier |
| Make Model Name | B727 Undifferentiated or Other Model |
| Operating Under FAR Part | Part 121 |
| Flight Phase | climbout : takeoff |
| Flight Plan | IFR |
| Aircraft 2 | |
| Operator | common carrier : air carrier |
| Make Model Name | B727 Undifferentiated or Other Model |
| Operating Under FAR Part | Part 121 |
| Flight Phase | climbout : takeoff |
| Flight Plan | IFR |
| Person 1 | |
| Affiliation | company : air carrier |
| Function | flight crew : first officer |
| Qualification | pilot : atp |
| Experience | flight time last 90 days : 150 flight time total : 8000 flight time type : 5000 |
| ASRS Report | 297803 |
| Person 2 | |
| Affiliation | company : air carrier |
| Function | flight crew : captain oversight : pic |
| Qualification | pilot : atp |
| Events | |
| Anomaly | conflict : ground less severe non adherence : published procedure non adherence : required legal separation |
| Independent Detector | other flight crewa |
| Resolutory Action | none taken : anomaly accepted |
| Consequence | Other |
| Miss Distance | horizontal : 5000 vertical : 0 |
| Supplementary | |
| Primary Problem | ATC Human Performance |
| Air Traffic Incident | Operational Error |
Narrative:
Air carrier Y ahead, a B-727, was cleared for takeoff. Air carrier X cleared into position and hold. As we were turning onto the runway we were told traffic ahead is a right turnout -- you are cleared for takeoff, straight out. We added power -- checked the instruments, it was night. At 80 KTS, thrust normal. We realized aircraft ahead was still on runway, appeared to be rotating for takeoff. We were approximately 25800 pounds less than maximum gross weight so I believe we were starting our rotation about 4000 ft down the runway. Aircraft ahead rolled approximately 10000 ft. I believe he was doing a flaps 5 degree takeoff and was heavy. He departed runway at the end. We departed the runway approximately mid field. Our climb rate was much steeper so we needed to look over the nose to keep him in sight. The danger in the situation would be if the first aircraft aborted his takeoff and the second aircraft needed to also. 2 aircraft trying to stop on the end of 1 runway could be disastrous. It is difficult to tell at night if the aircraft ahead is really airborne until it is 50 ft or so in the air. From the tower perspective, I doubt they can tell if an aircraft is airborne until it may be higher than that. Also, they may assume that same type aircraft would have similar takeoff roll -- which is not true because of different loads and flap settings. While I like to see traffic moved efficiently, safety is of the utmost importance. To prevent a recurrence -- don't take off -- until you are sure aircraft ahead is airborne. For tower -- if they knew estimated takeoff roll of the departing aircraft -- may help them in their spacing problems.
Original NASA ASRS Text
Title: ACR X TKOF ON OCCUPIED RWY HAD LTSS FROM ACR Y. SYS ERROR. NIGHT OP.
Narrative: ACR Y AHEAD, A B-727, WAS CLRED FOR TKOF. ACR X CLRED INTO POS AND HOLD. AS WE WERE TURNING ONTO THE RWY WE WERE TOLD TFC AHEAD IS A R TURNOUT -- YOU ARE CLRED FOR TKOF, STRAIGHT OUT. WE ADDED PWR -- CHKED THE INSTS, IT WAS NIGHT. AT 80 KTS, THRUST NORMAL. WE REALIZED ACFT AHEAD WAS STILL ON RWY, APPEARED TO BE ROTATING FOR TKOF. WE WERE APPROX 25800 LBS LESS THAN MAX GROSS WT SO I BELIEVE WE WERE STARTING OUR ROTATION ABOUT 4000 FT DOWN THE RWY. ACFT AHEAD ROLLED APPROX 10000 FT. I BELIEVE HE WAS DOING A FLAPS 5 DEG TKOF AND WAS HVY. HE DEPARTED RWY AT THE END. WE DEPARTED THE RWY APPROX MID FIELD. OUR CLB RATE WAS MUCH STEEPER SO WE NEEDED TO LOOK OVER THE NOSE TO KEEP HIM IN SIGHT. THE DANGER IN THE SIT WOULD BE IF THE FIRST ACFT ABORTED HIS TKOF AND THE SECOND ACFT NEEDED TO ALSO. 2 ACFT TRYING TO STOP ON THE END OF 1 RWY COULD BE DISASTROUS. IT IS DIFFICULT TO TELL AT NIGHT IF THE ACFT AHEAD IS REALLY AIRBORNE UNTIL IT IS 50 FT OR SO IN THE AIR. FROM THE TWR PERSPECTIVE, I DOUBT THEY CAN TELL IF AN ACFT IS AIRBORNE UNTIL IT MAY BE HIGHER THAN THAT. ALSO, THEY MAY ASSUME THAT SAME TYPE ACFT WOULD HAVE SIMILAR TKOF ROLL -- WHICH IS NOT TRUE BECAUSE OF DIFFERENT LOADS AND FLAP SETTINGS. WHILE I LIKE TO SEE TFC MOVED EFFICIENTLY, SAFETY IS OF THE UTMOST IMPORTANCE. TO PREVENT A RECURRENCE -- DON'T TAKE OFF -- UNTIL YOU ARE SURE ACFT AHEAD IS AIRBORNE. FOR TWR -- IF THEY KNEW ESTIMATED TKOF ROLL OF THE DEPARTING ACFT -- MAY HELP THEM IN THEIR SPACING PROBS.
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.