Flight crew of mdt commuter made takeoff at crw below published mins -- RVR.

Attributes
ACN	196445
Time
Date	199112
Day	Mon
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : crw
State Reference	WV
Altitude	agl bound lower : 0 agl bound upper : 0
Environment
Flight Conditions	IMC
Light	Daylight
Aircraft 1
Operator	common carrier : air carrier
Make Model Name	Medium Transport, High Wing, 2 Turboprop Eng
Flight Phase	climbout : takeoff
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : instrument pilot : commercial
Experience	flight time last 90 days : 200 flight time total : 4600 flight time type : 2700
ASRS Report	196445
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp pilot : instrument pilot : commercial
Events
Anomaly	non adherence : published procedure non adherence : far other anomaly other
Independent Detector	other flight crewa
Resolutory Action	none taken : anomaly accepted
Consequence	Other
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

Taxiing for takeoff, latest WX sequence report indicated visibility at 4 mi with light rain and fog. About 3000 ft from the approach end of runway 23, we noticed a fog bank envelope that end of the airport and observed an small transport executing a missed approach off the 'ILS 23.' I queried the local controller as to what the 'RVR' was for 'runway 23.' he reported 600 RVR for 'runway 23' and tower visibility at 1 1/2 SM in light rain and fog. I reported to the captain that by the regulations we needed a takeoff alternate. He commented that we would be okay, tower cleared us for takeoff, and without another word being spoken, the captain advanced power for takeoff. Fortunately, we did not have to return after departure. As an interesting side note, the captain I was flying with happens to be my domicile chief pilot. Ps, as I am writing this, it comes to my attention that even with a takeoff alternate we were still illegal to commence a departure. Our operation specifications say with 1 RVR transmissometer, we need 1600 RVR for a part 121 revenue flight.

Original NASA ASRS Text

Title: FLC OF MDT COMMUTER MADE TKOF AT CRW BELOW PUBLISHED MINS -- RVR.

Narrative: TAXIING FOR TKOF, LATEST WX SEQUENCE RPT INDICATED VISIBILITY AT 4 MI WITH LIGHT RAIN AND FOG. ABOUT 3000 FT FROM THE APCH END OF RWY 23, WE NOTICED A FOG BANK ENVELOPE THAT END OF THE ARPT AND OBSERVED AN SMT EXECUTING A MISSED APCH OFF THE 'ILS 23.' I QUERIED THE LCL CTLR AS TO WHAT THE 'RVR' WAS FOR 'RWY 23.' HE RPTED 600 RVR FOR 'RWY 23' AND TWR VISIBILITY AT 1 1/2 SM IN LIGHT RAIN AND FOG. I RPTED TO THE CAPT THAT BY THE REGS WE NEEDED A TKOF ALTERNATE. HE COMMENTED THAT WE WOULD BE OKAY, TWR CLRED US FOR TKOF, AND WITHOUT ANOTHER WORD BEING SPOKEN, THE CAPT ADVANCED PWR FOR TKOF. FORTUNATELY, WE DID NOT HAVE TO RETURN AFTER DEP. AS AN INTERESTING SIDE NOTE, THE CAPT I WAS FLYING WITH HAPPENS TO BE MY DOMICILE CHIEF PLT. PS, AS I AM WRITING THIS, IT COMES TO MY ATTN THAT EVEN WITH A TKOF ALTERNATE WE WERE STILL ILLEGAL TO COMMENCE A DEP. OUR OP SPECS SAY WITH 1 RVR TRANSMISSOMETER, WE NEED 1600 RVR FOR A PART 121 REVENUE 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.