B737-300 crew had the sliding window open at the start of the takeoff roll in sjc.

Attributes
ACN	495290
Time
Date	200012
Day	Fri
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : sjc.airport
State Reference	CA
Altitude	agl single value : 0
Environment
Flight Conditions	VMC
Light	Dawn
Aircraft 1
Operator	common carrier : air carrier
Make Model Name	B737-300
Operating Under FAR Part	Part 121
Navigation In Use	other
Flight Phase	ground : takeoff roll other
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 275 flight time total : 21000 flight time type : 17000
ASRS Report	495290
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : multi engine pilot : commercial pilot : instrument
Events
Anomaly	aircraft equipment problem : less severe non adherence : company policies non adherence : published procedure other anomaly other
Independent Detector	other flight crewa other flight crewb
Resolutory Action	flight crew : rejected takeoff other
Consequence	other
Supplementary
Problem Areas	Flight Crew Human Performance Company
Primary Problem	Flight Crew Human Performance

Narrative:

Flight was an originator. Since this particular gate at sjc has 2 originators, our aircraft was not at the gate when we arrived. We had approximately 15-20 mins from the time the aircraft arrived until pushback, which was on time. I would imagine that the crew that towed the aircraft from the remote spot to the jetway had occasion to open the captain's sliding window and probably did not close it completely. I was not yet (I am now) accustomed to checking the security of the window and of course being rushed this morning I forgot to insure that it was locked. When we advanced the throttles forward for takeoff, the increased airflow/pressurization caused the window to open with almost no forward motion on the aircraft. We retarded the throttles, aborted the takeoff, and taxied clear of the runway. After locking the sliding window, completing the pretkof checklist, and receiving takeoff clearance, we took off with no further incidents. In the future, I will not only check that my sliding window is locked, but also be more cognizant the cabin is pressurizing after engine start.

Original NASA ASRS Text

Title: B737-300 CREW HAD THE SLIDING WINDOW OPEN AT THE START OF THE TKOF ROLL IN SJC.

Narrative: FLT WAS AN ORIGINATOR. SINCE THIS PARTICULAR GATE AT SJC HAS 2 ORIGINATORS, OUR ACFT WAS NOT AT THE GATE WHEN WE ARRIVED. WE HAD APPROX 15-20 MINS FROM THE TIME THE ACFT ARRIVED UNTIL PUSHBACK, WHICH WAS ON TIME. I WOULD IMAGINE THAT THE CREW THAT TOWED THE ACFT FROM THE REMOTE SPOT TO THE JETWAY HAD OCCASION TO OPEN THE CAPT'S SLIDING WINDOW AND PROBABLY DID NOT CLOSE IT COMPLETELY. I WAS NOT YET (I AM NOW) ACCUSTOMED TO CHKING THE SECURITY OF THE WINDOW AND OF COURSE BEING RUSHED THIS MORNING I FORGOT TO INSURE THAT IT WAS LOCKED. WHEN WE ADVANCED THE THROTTLES FORWARD FOR TKOF, THE INCREASED AIRFLOW/PRESSURIZATION CAUSED THE WINDOW TO OPEN WITH ALMOST NO FORWARD MOTION ON THE ACFT. WE RETARDED THE THROTTLES, ABORTED THE TKOF, AND TAXIED CLR OF THE RWY. AFTER LOCKING THE SLIDING WINDOW, COMPLETING THE PRETKOF CHKLIST, AND RECEIVING TKOF CLRNC, WE TOOK OFF WITH NO FURTHER INCIDENTS. IN THE FUTURE, I WILL NOT ONLY CHK THAT MY SLIDING WINDOW IS LOCKED, BUT ALSO BE MORE COGNIZANT THE CABIN IS PRESSURIZING AFTER ENG START.

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.