Reporter believes he made a takeoff from iah in WX reported below RVR mins for takeoff.

Attributes
ACN	192396
Time
Date	199110
Day	Wed
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : iah
State Reference	TX
Altitude	agl bound lower : 0 agl bound upper : 0
Environment
Flight Conditions	Mixed
Light	Daylight
Aircraft 1
Operator	common carrier : air carrier
Make Model Name	Medium Large Transport, Low Wing, 2 Turbojet Eng
Flight Phase	climbout : takeoff ground other : taxi
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 100 flight time total : 2200 flight time type : 1000
ASRS Report	192396
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : commercial pilot : instrument
Events
Anomaly	non adherence : far non adherence : published procedure
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:

On oct/wed/91 I was PIC in an medium large transport aircraft operating under part 121 at iah airport. There was patchy fog around the airport, but the areas we had operated in the fog was very thin and visibility was at least a mi. During our taxi from ramp to runway 8 all of runway 14L was visible. The tower cleared us to hold in position on runway 8. I then asked the first officer for the 'before takeoff checklist'. The controller then cleared us for takeoff. At some point during this time the controller gave the RVR as 3500/1700/400 but because the visibility was so good, we could see the very end of runway 8, and because I was distracted by the before takeoff checklist, I thought the RVR report was for runway 9 (and for another aircraft). Because I could clearly see the end of the runway, the RVR report made no sense for runway 8, furthering my belief the RVR was for another runway. During takeoff roll visual contact was maintained with the end of the runway and beyond. Just before being handed off to departure control, I heard the tower give the RVR for runway 8 to another aircraft as 3500/1700/400. At that point I realized we had taken off with the roll out RVR being reported below 600. The takeoff was otherwise normal and no problems were encountered during the flight.

Original NASA ASRS Text

Title: RPTR BELIEVES HE MADE A TKOF FROM IAH IN WX RPTED BELOW RVR MINS FOR TKOF.

Narrative: ON OCT/WED/91 I WAS PIC IN AN MLG ACFT OPERATING UNDER PART 121 AT IAH ARPT. THERE WAS PATCHY FOG AROUND THE ARPT, BUT THE AREAS WE HAD OPERATED IN THE FOG WAS VERY THIN AND VISIBILITY WAS AT LEAST A MI. DURING OUR TAXI FROM RAMP TO RWY 8 ALL OF RWY 14L WAS VISIBLE. THE TWR CLRED US TO HOLD IN POS ON RWY 8. I THEN ASKED THE FO FOR THE 'BEFORE TKOF CHKLIST'. THE CTLR THEN CLRED US FOR TKOF. AT SOME POINT DURING THIS TIME THE CTLR GAVE THE RVR AS 3500/1700/400 BUT BECAUSE THE VISIBILITY WAS SO GOOD, WE COULD SEE THE VERY END OF RWY 8, AND BECAUSE I WAS DISTRACTED BY THE BEFORE TKOF CHKLIST, I THOUGHT THE RVR RPT WAS FOR RWY 9 (AND FOR ANOTHER ACFT). BECAUSE I COULD CLRLY SEE THE END OF THE RWY, THE RVR RPT MADE NO SENSE FOR RWY 8, FURTHERING MY BELIEF THE RVR WAS FOR ANOTHER RWY. DURING TKOF ROLL VISUAL CONTACT WAS MAINTAINED WITH THE END OF THE RWY AND BEYOND. JUST BEFORE BEING HANDED OFF TO DEP CTL, I HEARD THE TWR GIVE THE RVR FOR RWY 8 TO ANOTHER ACFT AS 3500/1700/400. AT THAT POINT I REALIZED WE HAD TAKEN OFF WITH THE ROLL OUT RVR BEING RPTED BELOW 600. THE TKOF WAS OTHERWISE NORMAL AND NO PROBLEMS WERE ENCOUNTERED DURING THE FLT.

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.