Air carrier X had less than standard separation from air carrier Y. System error.

Attributes
ACN	177101
Time
Date	199104
Day	Fri
Local Time Of Day	1801 To 2400
Place
Locale Reference	atc facility : mdw
State Reference	IL
Altitude	agl bound lower : 0 agl bound upper : 100
Environment
Flight Conditions	VMC
Light	Night
Aircraft 1
Operator	common carrier : air carrier
Make Model Name	Light Transport
Navigation In Use	Other Other
Flight Phase	ground : holding landing other
Flight Plan	IFR
Aircraft 2
Operator	common carrier : air carrier
Make Model Name	Medium Large Transport, Low Wing, 2 Turbojet Eng
Navigation In Use	Other Other
Flight Phase	climbout : takeoff
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 240 flight time total : 8000 flight time type : 3000
ASRS Report	177101
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : commercial pilot : instrument
Events
Anomaly	conflict : ground critical non adherence : clearance non adherence : published procedure non adherence : required legal separation
Independent Detector	other flight crewa
Resolutory Action	none taken : unable
Consequence	Other
Miss Distance	horizontal : 50 vertical : 100
Supplementary
Primary Problem	ATC Human Performance
Air Traffic Incident	Intra Facility Coordination Failure

Narrative:

Air carrier X landed on runway 4R at mdw during an extremely busy time. The controllers were pushing traffic. We were told 200 KTS to the OM. The conflict arose when the aircraft that landed ahead of us cleared runway 4R and began taxiing back along the parallel taxiway to the east of runway 4R. We landed and made an earlier turnoff and the controller requested we expedite clear of the runway. As I pulled off the runway, the taxiing aircraft was not yielding to us, so I had to stop. My tail must have been out on the runway when I thought I was clear. We switched to 121.90 for ground and that was the wrong frequency--it was 121.70. By the time we looked it up and switched, ground was screaming for us to clear the runway. Just as we did so, air carrier X went screaming by, having just rotated behind us. Contributing factors: local controller clearing air carrier Y for takeoff prior to us clearing the runway and contacting ground.

Original NASA ASRS Text

Title: ACR X HAD LESS THAN STANDARD SEPARATION FROM ACR Y. SYSTEM ERROR.

Narrative: ACR X LANDED ON RWY 4R AT MDW DURING AN EXTREMELY BUSY TIME. THE CTLRS WERE PUSHING TFC. WE WERE TOLD 200 KTS TO THE OM. THE CONFLICT AROSE WHEN THE ACFT THAT LANDED AHEAD OF US CLRED RWY 4R AND BEGAN TAXIING BACK ALONG THE PARALLEL TXWY TO THE E OF RWY 4R. WE LANDED AND MADE AN EARLIER TURNOFF AND THE CTLR REQUESTED WE EXPEDITE CLR OF THE RWY. AS I PULLED OFF THE RWY, THE TAXIING ACFT WAS NOT YIELDING TO US, SO I HAD TO STOP. MY TAIL MUST HAVE BEEN OUT ON THE RWY WHEN I THOUGHT I WAS CLR. WE SWITCHED TO 121.90 FOR GND AND THAT WAS THE WRONG FREQ--IT WAS 121.70. BY THE TIME WE LOOKED IT UP AND SWITCHED, GND WAS SCREAMING FOR US TO CLR THE RWY. JUST AS WE DID SO, ACR X WENT SCREAMING BY, HAVING JUST ROTATED BEHIND US. CONTRIBUTING FACTORS: LCL CTLR CLRING ACR Y FOR TKOF PRIOR TO US CLRING THE RWY AND CONTACTING GND.

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.