Narrative:

RVR on runway 5L at tys reported as 600' takeoff, 600' midpoint, 0' rollout. I assumed rollout to be inoperative since it had a 0 reading. Therefore, the 2 required readings were valid for use. Commercial chart was consulted on taxi out, and appeared to be valid information. Question now is, was rollout transmissometer inoperative because of 0 reading? Callback conversation with reporter revealed the following: reporter admits to further research on the RVR readout capabilities and has answered his own question. When an RVR reads 0 on one of the transmissometers, it is not broken.

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Original NASA ASRS Text

Title: NON ADHERENCE TO RVR REQUIREMENTS FOR TKOF.

Narrative: RVR ON RWY 5L AT TYS RPTED AS 600' TKOF, 600' MIDPOINT, 0' ROLLOUT. I ASSUMED ROLLOUT TO BE INOP SINCE IT HAD A 0 READING. THEREFORE, THE 2 REQUIRED READINGS WERE VALID FOR USE. COMMERCIAL CHART WAS CONSULTED ON TAXI OUT, AND APPEARED TO BE VALID INFO. QUESTION NOW IS, WAS ROLLOUT TRANSMISSOMETER INOP BECAUSE OF 0 READING? CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING: RPTR ADMITS TO FURTHER RESEARCH ON THE RVR READOUT CAPABILITIES AND HAS ANSWERED HIS OWN QUESTION. WHEN AN RVR READS 0 ON ONE OF THE TRANSMISSOMETERS, IT IS NOT BROKEN.

Data retrieved from NASA's ASRS site as of August 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.