Overweight takeoff. Wind report confusing.

Attributes
ACN	304570
Time
Date	199505
Day	Sun
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : mdw
State Reference	IL
Altitude	agl bound lower : 0 agl bound upper : 0
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tower : hya
Operator	common carrier : air carrier
Make Model Name	Commercial Fixed Wing
Operating Under FAR Part	Part 121
Flight Phase	climbout : takeoff
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : instrument pilot : atp
Experience	flight time last 90 days : 220 flight time total : 4500 flight time type : 600
ASRS Report	304570
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Events
Anomaly	non adherence : far other anomaly other
Independent Detector	other flight crewa
Resolutory Action	none taken : detected after the fact
Consequence	Other
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

We were overweight for takeoff so we selected a longer alternate runway. But ATIS winds were now tailwinds and correcting for tailwind, we inadvertently used the correction based on a wind reading tower provided to a landing aircraft and not to our aircraft. This latest wind was within our capability for takeoff, and takeoff was initiated within 2 mins but the reading should have been provided to our aircraft for legality.

Original NASA ASRS Text

Title: OVERWT TKOF. WIND RPT CONFUSING.

Narrative: WE WERE OVERWT FOR TKOF SO WE SELECTED A LONGER ALTERNATE RWY. BUT ATIS WINDS WERE NOW TAILWINDS AND CORRECTING FOR TAILWIND, WE INADVERTENTLY USED THE CORRECTION BASED ON A WIND READING TWR PROVIDED TO A LNDG ACFT AND NOT TO OUR ACFT. THIS LATEST WIND WAS WITHIN OUR CAPABILITY FOR TKOF, AND TKOF WAS INITIATED WITHIN 2 MINS BUT THE READING SHOULD HAVE BEEN PROVIDED TO OUR ACFT FOR LEGALITY.

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.