B747-200 flight crew responded to another aircraft's clearance after a long wait to cross active run...

Attributes
ACN	559669
Time
Date	200208
Day	Sun
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : ord.airport
State Reference	IL
Altitude	agl single value : 0
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Operator	common carrier : air carrier
Make Model Name	B747-200
Operating Under FAR Part	Part 121
Navigation In Use	other
Flight Phase	ground : holding ground : taxi
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : multi engine pilot : atp
Experience	flight time last 90 days : 84 flight time total : 5900 flight time type : 1100
ASRS Report	559669
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Events
Anomaly	incursion : runway non adherence : clearance
Independent Detector	other controllera
Resolutory Action	controller : issued advisory
Consequence	faa : reviewed incident with flight crew
Supplementary
Problem Areas	ATC Human Performance Flight Crew Human Performance
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

We landed on runway 27L at XA10L. After landing, we rolled to the end and were instructed by tower to exit right on taxiway M1, taxi back to taxiway K, hold short of runway 27L and remain on tower frequency. We complied and waited patiently for clearance to cross runway 27L and taxi to the ramp. Numerous aircraft landed and were clearing at taxiway T, which is prior to taxiway K. At approximately XA15, as an aircraft was clearing at taxiway T with another aircraft on approximately a 3 mi final, the tower radioed 'aircraft X cleared straight across.' I visually cleared the runway. Neither the aircraft clearing at taxiway T nor the aircraft on final was a factor and I stated 'cleared to cross.' tower then called, 'aircraft X, are you on?' as the captain responded we were and that we were crossing the runway, I started taxiing across the runway. Once we were across runway 27L, tower called back and said 'aircraft X, you were not cleared to cross.' the captain responded we had heard 'aircraft X cleared straight across.' tower responded that we took someone else's call sign, another similar call sign. We all had a big sinking feeling -- we were cleared, weren't we? The 3 pilots and an flight engineer on the flight deck all reconfirmed amongst ourselves that we all understood we were cleared to cross. There was never a conflict with any aircraft. The taxiing aircraft was clearing at taxiway T and the aircraft on short final was not sent around and landed normally. So how did we mistake 'aircraft X cleared straight across' for our clearance? We understood we were cleared to cross, and with an aircraft on short final we didn't want to delay. At busy airports, they want you to be prompt. In hindsight, maybe we should have waited for the tower to reconfirm the clearance, but then we all understood we were cleared across. Was the phraseology correct? Probably not. While I can't find the specific verbiage in aim, 7110.65 instructs controllers to state 'cross runway xx' when crossing an aircraft across. The clearance 'aircraft X cleared straight across' did not include the runway. So we should have reconfirmed the clearance before crossing. Lesson learned!

Original NASA ASRS Text

Title: B747-200 FLC RESPONDED TO ANOTHER ACFT'S CLRNC AFTER A LONG WAIT TO CROSS ACTIVE RWY FOR PARKING. THE 3 CREW MEMBERS BELIEVED THAT THEY HEARD THEIR ACFT CALL SIGN TO CROSS RWY.

Narrative: WE LANDED ON RWY 27L AT XA10L. AFTER LNDG, WE ROLLED TO THE END AND WERE INSTRUCTED BY TWR TO EXIT R ON TXWY M1, TAXI BACK TO TXWY K, HOLD SHORT OF RWY 27L AND REMAIN ON TWR FREQ. WE COMPLIED AND WAITED PATIENTLY FOR CLRNC TO CROSS RWY 27L AND TAXI TO THE RAMP. NUMEROUS ACFT LANDED AND WERE CLRING AT TXWY T, WHICH IS PRIOR TO TXWY K. AT APPROX XA15, AS AN ACFT WAS CLRING AT TXWY T WITH ANOTHER ACFT ON APPROX A 3 MI FINAL, THE TWR RADIOED 'ACFT X CLRED STRAIGHT ACROSS.' I VISUALLY CLRED THE RWY. NEITHER THE ACFT CLRING AT TXWY T NOR THE ACFT ON FINAL WAS A FACTOR AND I STATED 'CLRED TO CROSS.' TWR THEN CALLED, 'ACFT X, ARE YOU ON?' AS THE CAPT RESPONDED WE WERE AND THAT WE WERE XING THE RWY, I STARTED TAXIING ACROSS THE RWY. ONCE WE WERE ACROSS RWY 27L, TWR CALLED BACK AND SAID 'ACFT X, YOU WERE NOT CLRED TO CROSS.' THE CAPT RESPONDED WE HAD HEARD 'ACFT X CLRED STRAIGHT ACROSS.' TWR RESPONDED THAT WE TOOK SOMEONE ELSE'S CALL SIGN, ANOTHER SIMILAR CALL SIGN. WE ALL HAD A BIG SINKING FEELING -- WE WERE CLRED, WEREN'T WE? THE 3 PLTS AND AN FE ON THE FLT DECK ALL RECONFIRMED AMONGST OURSELVES THAT WE ALL UNDERSTOOD WE WERE CLRED TO CROSS. THERE WAS NEVER A CONFLICT WITH ANY ACFT. THE TAXIING ACFT WAS CLRING AT TXWY T AND THE ACFT ON SHORT FINAL WAS NOT SENT AROUND AND LANDED NORMALLY. SO HOW DID WE MISTAKE 'ACFT X CLRED STRAIGHT ACROSS' FOR OUR CLRNC? WE UNDERSTOOD WE WERE CLRED TO CROSS, AND WITH AN ACFT ON SHORT FINAL WE DIDN'T WANT TO DELAY. AT BUSY ARPTS, THEY WANT YOU TO BE PROMPT. IN HINDSIGHT, MAYBE WE SHOULD HAVE WAITED FOR THE TWR TO RECONFIRM THE CLRNC, BUT THEN WE ALL UNDERSTOOD WE WERE CLRED ACROSS. WAS THE PHRASEOLOGY CORRECT? PROBABLY NOT. WHILE I CAN'T FIND THE SPECIFIC VERBIAGE IN AIM, 7110.65 INSTRUCTS CTLRS TO STATE 'CROSS RWY XX' WHEN XING AN ACFT ACROSS. THE CLRNC 'ACFT X CLRED STRAIGHT ACROSS' DID NOT INCLUDE THE RWY. SO WE SHOULD HAVE RECONFIRMED THE CLRNC BEFORE XING. LESSON LEARNED!

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.

B747-200 flight crew responded to another aircraft's clearance after a long wait to cross active runway for parking. The 3 crew members believed that they heard their aircraft call sign to cross runway.