Unauthorized runway crossing by air carrier.

Attributes
ACN	191756
Time
Date	199110
Day	Wed
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : mdw
State Reference	IL
Altitude	agl bound lower : 0 agl bound upper : 0
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tower : prc
Operator	common carrier : air carrier
Make Model Name	Medium Large Transport, Low Wing, 2 Turbojet Eng
Navigation In Use	Other Other
Flight Phase	ground other : taxi
Flight Plan	IFR
Aircraft 2
Operator	common carrier : air carrier
Make Model Name	Medium Large Transport, Low Wing, 2 Turbojet Eng
Flight Phase	ground other : taxi
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp pilot : cfi
Experience	flight time last 90 days : 270 flight time total : 18000 flight time type : 11000
ASRS Report	191756
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp
Experience	flight time last 90 days : 140 flight time total : 10400 flight time type : 550
ASRS Report	191755
Events
Anomaly	incursion : runway non adherence : far non adherence : clearance
Independent Detector	other controllera
Resolutory Action	none taken : detected after the fact
Consequence	Other
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation other

Narrative:

Taxiing for takeoff, ground control said 'cleared to taxi to runway 31C via poppa, hold short 31R, follow air carrier Y coming from your left.' we acknowledged. As we held short of 31R, ground control said, 'air carrier Y, cleared to cross 31R, hold short 31C.' we assumed we were to follow air carrier Y and did so! Ground then said, 'air carrier X you weren't cleared to cross.' no other traffic was involved. Callback conversation with reporter revealed the following information: reporter said several times that both he and first officer were sure that they had clearance to follow air carrier Y across the runway even though the ground controller did not give them a specific clearance to do so. Think ground controller was using the technique to cut down on number of transmissions needed. Ground controller did jump on them for crossing runway without clearance. No follow-up action by FAA. No conflict with other aircraft or vehicles.

Original NASA ASRS Text

Title: UNAUTHORIZED RWY XING BY ACR.

Narrative: TAXIING FOR TKOF, GND CTL SAID 'CLRED TO TAXI TO RWY 31C VIA POPPA, HOLD SHORT 31R, FOLLOW ACR Y COMING FROM YOUR L.' WE ACKNOWLEDGED. AS WE HELD SHORT OF 31R, GND CTL SAID, 'ACR Y, CLRED TO CROSS 31R, HOLD SHORT 31C.' WE ASSUMED WE WERE TO FOLLOW ACR Y AND DID SO! GND THEN SAID, 'ACR X YOU WEREN'T CLRED TO CROSS.' NO OTHER TFC WAS INVOLVED. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: RPTR SAID SEVERAL TIMES THAT BOTH HE AND FO WERE SURE THAT THEY HAD CLRNC TO FOLLOW ACR Y ACROSS THE RWY EVEN THOUGH THE GND CTLR DID NOT GIVE THEM A SPECIFIC CLRNC TO DO SO. THINK GND CTLR WAS USING THE TECHNIQUE TO CUT DOWN ON NUMBER OF TRANSMISSIONS NEEDED. GND CTLR DID JUMP ON THEM FOR XING RWY WITHOUT CLRNC. NO FOLLOW-UP ACTION BY FAA. NO CONFLICT WITH OTHER ACFT OR VEHICLES.

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.