Narrative:

Flight air carrier X landed on runway 34L seattle. During landing rollout, tower instructed, 'air carrier X turn right and right again, hold short runway 34R.' I read back, 'air carrier X, 2 right turns, hold short runway 34R.' after clearing runway 34L at taxiway H, I started my after landing checklist flow. The captain asked, 'are we cleared across runway 34R?' I said, 'no' and he immediately stopped the aircraft. I called the tower and said 'stop air carrier Y's takeoff on runway 34R, our nose is 3 ft over the line.' air carrier Y stopped his takeoff and taxied clear at taxiway north or taxiway M. We were cleared across runway 34R and later told to phone the tower. Contributing factors: 1) fatigue: it was XA00 body time and we had flown 7 hours of flight time that day. 2) low time: I had 40 hours in model, the captain 120 hours. 3) darkness: the area between runway 34L&right is a dark area. 4) distraction: I being new to the aircraft, so I was doublechking myself to ensure completion of the after landing checklist. 5) unusual taxi instructions: the 2 right turns, a high speed to a reverse high speed gave a strange angle to the runway lights of runway 34R.

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Original NASA ASRS Text

Title: RWY INCURSION BY A B737-800 FLC WITH ANOTHER ACR ABOUT TO ROLL ON RWY 34R AT SEATAC, WA.

Narrative: FLT ACR X LANDED ON RWY 34L SEATTLE. DURING LNDG ROLLOUT, TWR INSTRUCTED, 'ACR X TURN R AND R AGAIN, HOLD SHORT RWY 34R.' I READ BACK, 'ACR X, 2 R TURNS, HOLD SHORT RWY 34R.' AFTER CLRING RWY 34L AT TXWY H, I STARTED MY AFTER LNDG CHKLIST FLOW. THE CAPT ASKED, 'ARE WE CLRED ACROSS RWY 34R?' I SAID, 'NO' AND HE IMMEDIATELY STOPPED THE ACFT. I CALLED THE TWR AND SAID 'STOP ACR Y'S TKOF ON RWY 34R, OUR NOSE IS 3 FT OVER THE LINE.' ACR Y STOPPED HIS TKOF AND TAXIED CLR AT TXWY N OR TXWY M. WE WERE CLRED ACROSS RWY 34R AND LATER TOLD TO PHONE THE TWR. CONTRIBUTING FACTORS: 1) FATIGUE: IT WAS XA00 BODY TIME AND WE HAD FLOWN 7 HRS OF FLT TIME THAT DAY. 2) LOW TIME: I HAD 40 HRS IN MODEL, THE CAPT 120 HRS. 3) DARKNESS: THE AREA BTWN RWY 34L&R IS A DARK AREA. 4) DISTR: I BEING NEW TO THE ACFT, SO I WAS DOUBLECHKING MYSELF TO ENSURE COMPLETION OF THE AFTER LNDG CHKLIST. 5) UNUSUAL TAXI INSTRUCTIONS: THE 2 R TURNS, A HIGH SPD TO A REVERSE HIGH SPD GAVE A STRANGE ANGLE TO THE RWY LIGHTS OF RWY 34R.

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.