MD80 captain is unsure of operation specification requirements for low visibility takeoff.

Attributes
ACN	721221
Time
Date	200612
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : pia.airport
State Reference	IL
Altitude	agl single value : 0
Environment
Weather Elements	Fog
Light	Daylight
Aircraft 1
Operator	common carrier : air carrier
Make Model Name	MD-80 Series (DC-9-80) Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Flight Phase	ground : takeoff roll
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : cfi pilot : commercial pilot : atp
Experience	flight time last 90 days : 120 flight time total : 7000 flight time type : 2400
ASRS Report	721221
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Events
Anomaly	non adherence : company policies non adherence : far
Independent Detector	other flight crewa
Resolutory Action	none taken : detected after the fact
Supplementary
Problem Areas	Company Flight Crew Human Performance
Primary Problem	Flight Crew Human Performance

Narrative:

I took off runway 31 with 800 ft RVR touchdown; 700 ft RVR rollout believing I was both safe and legal to do so. Upon further review I am unsure of the legality; and am further confused with company operations specification. I understand the operations specification to state: 1) if taking off with standard or less than standard minimums; use this operations specification as supposed to airport diagram. 2) low RVR takeoff requires 2 operating RVR system which are controling for visibility. 3) you must be able to determine the centerline of the runway either with centerline lighting or with centerline markings (I had centerline markings). Upon further review of the operations specification (after takeoff) I am unsure if I needed centerline lighting; and if I needed airport diagram to say this was approved. Factors: visibility had dropped from 1/2 to 1/4 mi on ATIS. 10 mins prior to departure and ground control reported RVR 1200 ft. Dispatch was contacted with this information; and a takeoff alternate was determined. Cleared to taxi to runway 31 with RVR reported prior to takeoff as stated above. Believing adequate legality and safety; an uneventful takeoff was initiated with the first officer as PF. After airborne; I decided to confirm my decision to take off with reduced visibility and became unsure of the legality.

Original NASA ASRS Text

Title: MD80 CAPT IS UNSURE OF OP SPEC REQUIREMENTS FOR LOW VISIBILITY TKOF.

Narrative: I TOOK OFF RWY 31 WITH 800 FT RVR TOUCHDOWN; 700 FT RVR ROLLOUT BELIEVING I WAS BOTH SAFE AND LEGAL TO DO SO. UPON FURTHER REVIEW I AM UNSURE OF THE LEGALITY; AND AM FURTHER CONFUSED WITH COMPANY OPS SPEC. I UNDERSTAND THE OPS SPEC TO STATE: 1) IF TAKING OFF WITH STANDARD OR LESS THAN STANDARD MINIMUMS; USE THIS OPS SPEC AS SUPPOSED TO ARPT DIAGRAM. 2) LOW RVR TKOF REQUIRES 2 OPERATING RVR SYS WHICH ARE CTLING FOR VISIBILITY. 3) YOU MUST BE ABLE TO DETERMINE THE CTRLINE OF THE RWY EITHER WITH CTRLINE LIGHTING OR WITH CTRLINE MARKINGS (I HAD CTRLINE MARKINGS). UPON FURTHER REVIEW OF THE OPS SPEC (AFTER TKOF) I AM UNSURE IF I NEEDED CTRLINE LIGHTING; AND IF I NEEDED ARPT DIAGRAM TO SAY THIS WAS APPROVED. FACTORS: VISIBILITY HAD DROPPED FROM 1/2 TO 1/4 MI ON ATIS. 10 MINS PRIOR TO DEP AND GND CTL RPTED RVR 1200 FT. DISPATCH WAS CONTACTED WITH THIS INFO; AND A TKOF ALTERNATE WAS DETERMINED. CLRED TO TAXI TO RWY 31 WITH RVR RPTED PRIOR TO TKOF AS STATED ABOVE. BELIEVING ADEQUATE LEGALITY AND SAFETY; AN UNEVENTFUL TKOF WAS INITIATED WITH THE FO AS PF. AFTER AIRBORNE; I DECIDED TO CONFIRM MY DECISION TO TAKE OFF WITH REDUCED VISIBILITY AND BECAME UNSURE OF THE LEGALITY.

Data retrieved from NASA's ASRS site as of January 2009 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.