Air carrier medium large transport flight crew initiates takeoff in less than minimum RVR.

Attributes
ACN	163821
Time
Date	199011
Day	Sun
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : sea
State Reference	WA
Altitude	agl bound lower : 0 agl bound upper : 0
Environment
Flight Conditions	IMC
Light	Daylight
Aircraft 1
Controlling Facilities	tower : cle
Operator	common carrier : air carrier
Make Model Name	Medium Large Transport, Low Wing, 2 Turbojet Eng
Flight Phase	climbout : takeoff
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 160 flight time total : 10000 flight time type : 3200
ASRS Report	163821
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : commercial pilot : instrument
Events
Anomaly	non adherence : published procedure non adherence other 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:

When we switched over to tower we were #5 for takeoff on 34L. As tower cleared each aircraft for takeoff, RVR's of 3500' T/D, 1200' midpoint, and 500' rollout were given for 34L. The first takeoff was air carrier B. My first officer thought that air carrier B takeoff was illegal because of the 500' RVR at rollout. I thought it was a legal takeoff based on T/D RVR of 3500' and that T/D RVR was controling and 1600' was the first lower minimum. My thinking was reinforced when air carrier C took off with this same RVR report from tower. Thinking these 2 crews would be more familiar with this type of situation than I (as I fly in less fog and winter WX than they do) only reinforced my interpretation. I accepted takeoff clearance with RVR's of 3500', 1200' and 500'. The takeoff was normal. After some review of our operations specifications, and discussion with other pilots and my fleet manager. I feel this was not a legal takeoff. I don't feel that safety was compromised. I'm still doing some research on these takeoff visibility rules and am suggestion to our training department that ground school discussions be less sterile. For a better understanding, scenarios such as this and others should be included in training programs.

Original NASA ASRS Text

Title: ACR MLG FLT CREW INITIATES TKOF IN LESS THAN MINIMUM RVR.

Narrative: WHEN WE SWITCHED OVER TO TWR WE WERE #5 FOR TKOF ON 34L. AS TWR CLRED EACH ACFT FOR TKOF, RVR'S OF 3500' T/D, 1200' MIDPOINT, AND 500' ROLLOUT WERE GIVEN FOR 34L. THE FIRST TKOF WAS ACR B. MY F/O THOUGHT THAT ACR B TKOF WAS ILLEGAL BECAUSE OF THE 500' RVR AT ROLLOUT. I THOUGHT IT WAS A LEGAL TKOF BASED ON T/D RVR OF 3500' AND THAT T/D RVR WAS CTLING AND 1600' WAS THE FIRST LOWER MINIMUM. MY THINKING WAS REINFORCED WHEN ACR C TOOK OFF WITH THIS SAME RVR RPT FROM TWR. THINKING THESE 2 CREWS WOULD BE MORE FAMILIAR WITH THIS TYPE OF SITUATION THAN I (AS I FLY IN LESS FOG AND WINTER WX THAN THEY DO) ONLY REINFORCED MY INTERP. I ACCEPTED TKOF CLRNC WITH RVR'S OF 3500', 1200' AND 500'. THE TKOF WAS NORMAL. AFTER SOME REVIEW OF OUR OPS SPECS, AND DISCUSSION WITH OTHER PLTS AND MY FLEET MGR. I FEEL THIS WAS NOT A LEGAL TKOF. I DON'T FEEL THAT SAFETY WAS COMPROMISED. I'M STILL DOING SOME RESEARCH ON THESE TKOF VISIBILITY RULES AND AM SUGGESTION TO OUR TRNING DEPT THAT GND SCHOOL DISCUSSIONS BE LESS STERILE. FOR A BETTER UNDERSTANDING, SCENARIOS SUCH AS THIS AND OTHERS SHOULD BE INCLUDED IN TRNING PROGRAMS.

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.