An air carrier medium large transport may have crossed a runway without clearance.

Attributes
ACN	318964
Time
Date	199510
Day	Sun
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : sfo
State Reference	CA
Altitude	agl bound lower : 0 agl bound upper : 0
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Operator	common carrier : air carrier
Make Model Name	Commercial Fixed Wing
Operating Under FAR Part	Part 121
Navigation In Use	Other Other
Flight Phase	ground other : taxi
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : instrument pilot : flight engineer pilot : commercial pilot : atp
Experience	flight time last 90 days : 220 flight time total : 12000 flight time type : 4800
ASRS Report	318964
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : flight engineer pilot : atp
Experience	flight time last 90 days : 200 flight time total : 12000 flight time type : 6000
ASRS Report	319063
Events
Anomaly	incursion : runway
Independent Detector	other controllera
Resolutory Action	none taken : detected after the fact other
Consequence	faa : reviewed incident with flight crew
Supplementary
Primary Problem	ATC Human Performance
Air Traffic Incident	other
Situations
ATC Facility	procedure or policy : unspecified

Narrative:

When we received our initial taxi instruction at sfo, we were cleared to taxi to runway 28L via taxiway a, taxiway F, hold short runway 1L. While holding short of runway 1L, ground control cleared an aircraft to cross runway 1L, hold short runway 1R and then contact tower on 120.5. The call sign for the cleared aircraft was blocked by another radio transmission. I asked that ground control repeat his clearance because it was blocked. He repeated the clearance, and this time we heard our call sign. I read back the clearance, the captain then proceeded to cross runway 1L (with an aircraft holding in position on runway 1L). After we crossed runway 1L, short of runway 1R, I contacted the tower on 120.5. The tower informed us that we had crossed runway 1L without clearance. I told tower that ground control had cleared us to cross runway 1L. He replied that the tower supervisor would review the tape. I believe a contributing factor is that it is very inconsistent who controls the crossing of active runways. Supplemental information from acn 319063: upon arrival at msy, I called sfo tower, but the person in charge had gone home. I left my name and telephone number. The copilot and I are very sure of our actions based on our issued clrncs.

Original NASA ASRS Text

Title: AN ACR MLG MAY HAVE CROSSED A RWY WITHOUT CLRNC.

Narrative: WHEN WE RECEIVED OUR INITIAL TAXI INSTRUCTION AT SFO, WE WERE CLRED TO TAXI TO RWY 28L VIA TXWY A, TXWY F, HOLD SHORT RWY 1L. WHILE HOLDING SHORT OF RWY 1L, GND CTL CLRED AN ACFT TO CROSS RWY 1L, HOLD SHORT RWY 1R AND THEN CONTACT TWR ON 120.5. THE CALL SIGN FOR THE CLRED ACFT WAS BLOCKED BY ANOTHER RADIO XMISSION. I ASKED THAT GND CTL REPEAT HIS CLRNC BECAUSE IT WAS BLOCKED. HE REPEATED THE CLRNC, AND THIS TIME WE HEARD OUR CALL SIGN. I READ BACK THE CLRNC, THE CAPT THEN PROCEEDED TO CROSS RWY 1L (WITH AN ACFT HOLDING IN POS ON RWY 1L). AFTER WE CROSSED RWY 1L, SHORT OF RWY 1R, I CONTACTED THE TWR ON 120.5. THE TWR INFORMED US THAT WE HAD CROSSED RWY 1L WITHOUT CLRNC. I TOLD TWR THAT GND CTL HAD CLRED US TO CROSS RWY 1L. HE REPLIED THAT THE TWR SUPVR WOULD REVIEW THE TAPE. I BELIEVE A CONTRIBUTING FACTOR IS THAT IT IS VERY INCONSISTENT WHO CTLS THE XING OF ACTIVE RWYS. SUPPLEMENTAL INFO FROM ACN 319063: UPON ARR AT MSY, I CALLED SFO TWR, BUT THE PERSON IN CHARGE HAD GONE HOME. I LEFT MY NAME AND TELEPHONE NUMBER. THE COPLT AND I ARE VERY SURE OF OUR ACTIONS BASED ON OUR ISSUED CLRNCS.

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.