The captain's sliding window became unlocked on aircraft rotation.

Attributes
ACN	253106
Time
Date	199310
Day	Sat
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : lga
State Reference	NY
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	Large Transport, Low Wing, 2 Turbojet Eng
Navigation In Use	Other Other
Flight Phase	climbout : takeoff ground : preflight
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : commercial pilot : instrument pilot : atp
Experience	flight time last 90 days : 85 flight time total : 9550 flight time type : 700
ASRS Report	253106
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : commercial pilot : instrument
Events
Anomaly	aircraft equipment problem : less severe other anomaly other
Independent Detector	other flight crewa
Resolutory Action	none taken : unable other
Consequence	Other
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

On takeoff the captain's window developed an air leak at about 100-120 KTS. On climb out the window tried to open. The window handle was locked forward and the window indicator said 'closed.' we notified the tower and departure of our problem and returned to lga with no other problem except the wind noise. Lga controllers were very helpful and professional. The problem could have been averted had I, the captain, noticed that the back support arm was not completely over center. It appeared okay to myself and the copilot, but there is no over center alignment mark on this support arm. The window appeared closed and locked as per the checklist. I recommend the primary indication for a closed window be an over center alignment mark scribed on the track and support arm.

Original NASA ASRS Text

Title: THE CAPT'S SLIDING WINDOW BECAME UNLOCKED ON ACFT ROTATION.

Narrative: ON TKOF THE CAPT'S WINDOW DEVELOPED AN AIR LEAK AT ABOUT 100-120 KTS. ON CLBOUT THE WINDOW TRIED TO OPEN. THE WINDOW HANDLE WAS LOCKED FORWARD AND THE WINDOW INDICATOR SAID 'CLOSED.' WE NOTIFIED THE TWR AND DEP OF OUR PROB AND RETURNED TO LGA WITH NO OTHER PROB EXCEPT THE WIND NOISE. LGA CTLRS WERE VERY HELPFUL AND PROFESSIONAL. THE PROB COULD HAVE BEEN AVERTED HAD I, THE CAPT, NOTICED THAT THE BACK SUPPORT ARM WAS NOT COMPLETELY OVER CTR. IT APPEARED OKAY TO MYSELF AND THE COPLT, BUT THERE IS NO OVER CTR ALIGNMENT MARK ON THIS SUPPORT ARM. THE WINDOW APPEARED CLOSED AND LOCKED AS PER THE CHKLIST. I RECOMMEND THE PRIMARY INDICATION FOR A CLOSED WINDOW BE AN OVER CTR ALIGNMENT MARK SCRIBED ON THE TRACK AND SUPPORT ARM.

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.