An MD80 captain reported that he departed yul without the WX being reported in mi, as is required by...

Attributes
ACN	513090
Time
Date	200105
Day	Mon
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : cyul.airport
State Reference	PQ
Altitude	agl single value : 0
Environment
Flight Conditions	IMC
Light	Daylight
Aircraft 1
Operator	common carrier : air carrier
Make Model Name	MD-80 Series (DC-9-80) Undifferentiated or Other Model
Flight Phase	climbout : takeoff
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
ASRS Report	513090
Events
Anomaly	non adherence : published procedure non adherence : company policies non adherence : far
Resolutory Action	none taken : detected after the fact
Supplementary
Problem Areas	ATC Human Performance Flight Crew Human Performance
Primary Problem	Flight Crew Human Performance

Narrative:

Foggy conditions at yul airport. We expected runway 24L for takeoff and reviewed takeoff legality for runway 24L/RVR 600 ft. Prevailing visibility was reported at 1/8 mi. En route to runway 24L, the departure runway was changed to runway 6R. Visibility required for runway 6R was 1/4 mi. We were third in line for takeoff and the visibility started improving rapidly. Tower reported RVR at 3300 ft. The 2 aircraft ahead departed. RVR-a was reported again at 3300 ft. I mentally calculated that to be well above 1/4 mi and we took off. During later discussion, we determined that we should have requested a visibility reported in mi as that was the controling factor for runway 6R and the RVR values being called by the tower, technically pertained to runway 24L only. This ATIS published 5 mins after our takeoff reported visibility at 1/2 mi. I am confident in the safety of my decision to depart, but should have asked for the visibility in mi, as required by FARS, to be legal. I don't think the tower should volunteer RVR values if they are not pertinent to the runway in use. This action just sets a takeoff legality trap for the pilots.

Original NASA ASRS Text

Title: AN MD80 CAPT RPTED THAT HE DEPARTED YUL WITHOUT THE WX BEING RPTED IN MI, AS IS REQUIRED BY THE FARS TO BE LEGAL. HOWEVER, THE MEASUREMENT, GIVEN IN FT, INDICATED THERE WAS SUFFICIENT VISIBILITY FOR DEP.

Narrative: FOGGY CONDITIONS AT YUL ARPT. WE EXPECTED RWY 24L FOR TKOF AND REVIEWED TKOF LEGALITY FOR RWY 24L/RVR 600 FT. PREVAILING VISIBILITY WAS RPTED AT 1/8 MI. ENRTE TO RWY 24L, THE DEP RWY WAS CHANGED TO RWY 6R. VISIBILITY REQUIRED FOR RWY 6R WAS 1/4 MI. WE WERE THIRD IN LINE FOR TKOF AND THE VISIBILITY STARTED IMPROVING RAPIDLY. TWR RPTED RVR AT 3300 FT. THE 2 ACFT AHEAD DEPARTED. RVR-A WAS RPTED AGAIN AT 3300 FT. I MENTALLY CALCULATED THAT TO BE WELL ABOVE 1/4 MI AND WE TOOK OFF. DURING LATER DISCUSSION, WE DETERMINED THAT WE SHOULD HAVE REQUESTED A VISIBILITY RPTED IN MI AS THAT WAS THE CTLING FACTOR FOR RWY 6R AND THE RVR VALUES BEING CALLED BY THE TWR, TECHNICALLY PERTAINED TO RWY 24L ONLY. THIS ATIS PUBLISHED 5 MINS AFTER OUR TKOF RPTED VISIBILITY AT 1/2 MI. I AM CONFIDENT IN THE SAFETY OF MY DECISION TO DEPART, BUT SHOULD HAVE ASKED FOR THE VISIBILITY IN MI, AS REQUIRED BY FARS, TO BE LEGAL. I DON'T THINK THE TWR SHOULD VOLUNTEER RVR VALUES IF THEY ARE NOT PERTINENT TO THE RWY IN USE. THIS ACTION JUST SETS A TKOF LEGALITY TRAP FOR THE PLTS.

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.

An MD80 captain reported that he departed yul without the WX being reported in mi, as is required by the FARS to be legal. However, the measurement, given in ft, indicated there was sufficient visibility for departure.