Air carrier medium large transport flight crew conducts below minimums takeoff at isp.

Attributes
ACN	177216
Time
Date	199105
Day	Wed
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : isp
State Reference	NY
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 Large Transport, Low Wing, 2 Turbojet Eng
Flight Phase	climbout : takeoff ground : preflight
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : flight engineer pilot : cfi pilot : atp
Experience	flight time last 90 days : 220 flight time total : 11800 flight time type : 4000
ASRS Report	177219
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp pilot : cfi
Experience	flight time last 90 days : 180 flight time total : 11200 flight time type : 2000
ASRS Report	177214
Events
Anomaly	non adherence : published procedure non adherence : far other anomaly other
Independent Detector	other controllera other flight crewa
Resolutory Action	none taken : anomaly accepted
Consequence	Other
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

WX report at isp from xx:30 until xy:50: sky obscured, visibility 0, temperature/dew point 53 degrees F, winds calm. Tower advising visibility at 0 and RVV at 1/16. RVV is not defined under far part 91 or 121, but copied from commercial chart glossary, as attached. RVV is not noted anywhere on isp approach charts or airport diagram (attached) as to takeoff minimums application. At xy:55 ATIS was giving visibility at 1/4 mi. Tower then reported visibility had improved to 1/4 mi, RVV at 3/16. We advised we had our takeoff minimums, proceeded to the runway and took off ahead of waiting commuter and other airline flts, also advising they had their minimums as well. After takeoff we checked further as to applicability of RVV, defined in glossary and operating specifications, but does not specifically say it is required or to be used as only basis unless visibility is not available, but what visibility--tower or what? My decision to takeoff was valid as tower advised 1/4 visibility and that is minimums south noted on takeoff minimums, but maybe the man in the tower didn't think so. But all he had asked was our minimums. 1/4 mi and that was that.

Original NASA ASRS Text

Title: ACR MLG FLT CREW CONDUCTS BELOW MINIMUMS TKOF AT ISP.

Narrative: WX RPT AT ISP FROM XX:30 UNTIL XY:50: SKY OBSCURED, VISIBILITY 0, TEMP/DEW POINT 53 DEGS F, WINDS CALM. TWR ADVISING VISIBILITY AT 0 AND RVV AT 1/16. RVV IS NOT DEFINED UNDER FAR PART 91 OR 121, BUT COPIED FROM COMMERCIAL CHART GLOSSARY, AS ATTACHED. RVV IS NOT NOTED ANYWHERE ON ISP APCH CHARTS OR ARPT DIAGRAM (ATTACHED) AS TO TKOF MINIMUMS APPLICATION. AT XY:55 ATIS WAS GIVING VISIBILITY AT 1/4 MI. TWR THEN RPTED VISIBILITY HAD IMPROVED TO 1/4 MI, RVV AT 3/16. WE ADVISED WE HAD OUR TKOF MINIMUMS, PROCEEDED TO THE RWY AND TOOK OFF AHEAD OF WAITING COMMUTER AND OTHER AIRLINE FLTS, ALSO ADVISING THEY HAD THEIR MINIMUMS AS WELL. AFTER TKOF WE CHKED FURTHER AS TO APPLICABILITY OF RVV, DEFINED IN GLOSSARY AND OPERATING SPECS, BUT DOES NOT SPECIFICALLY SAY IT IS REQUIRED OR TO BE USED AS ONLY BASIS UNLESS VISIBILITY IS NOT AVAILABLE, BUT WHAT VISIBILITY--TWR OR WHAT? MY DECISION TO TKOF WAS VALID AS TWR ADVISED 1/4 VISIBILITY AND THAT IS MINIMUMS S NOTED ON TKOF MINIMUMS, BUT MAYBE THE MAN IN THE TWR DIDN'T THINK SO. BUT ALL HE HAD ASKED WAS OUR MINIMUMS. 1/4 MI AND THAT WAS THAT.

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.