A dornier 328 flight crew landed below minimums at cyow.

Attributes
ACN	456572
Time
Date	199912
Day	Sat
Local Time Of Day	1801 To 2400
Place
Locale Reference	airport : cyow.airport
State Reference	ON
Altitude	agl single value : 0
Environment
Flight Conditions	IMC
Weather Elements	Fog Rain
Light	Night
Aircraft 1
Operator	common carrier : air carrier
Make Model Name	Do 328 TP (Turboprop)
Operating Under FAR Part	Part 121
Navigation In Use	ils localizer & glide slope : 7
Flight Phase	landing : roll
Route In Use	approach : instrument precision
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : cfi pilot : commercial pilot : instrument pilot : multi engine
Experience	flight time last 90 days : 200 flight time total : 4200 flight time type : 900
ASRS Report	456572
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Events
Anomaly	inflight encounter : weather non adherence : published procedure non adherence : far
Independent Detector	other flight crewa other flight crewb
Resolutory Action	none taken : detected after the fact
Supplementary
Problem Areas	Flight Crew Human Performance
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

We flew an ILS approach to runway 7 at cyow and landed with less than required visibility. We were cleared for ILS approach. WX was 300 ft overcast, visibility 1 3/4 mi, RVR 3000 ft. Approach control stated ceiling 200 ft overcast, visibility 1 1/4 mi, RVR 2000 ft, lights stage 5, cleared to land. The captain rogered the call and we continued approach. Tower once again stated the same WX, 200 ft overcast, visibility 1 1/4 mi, RVR 2000 ft, cleared to land. In our operations manual there is a chart for operations in canadian airspace on how to convert metric to RVR and united states visibility. We figured converted RVR from 2000 meters would be about 1 1/4 mi, which agreed with tower report of visibility in mi. Upon landing we mentioned visibility seemed a lot less than 1 1/4 mi. We discussed this and concluded that RVR was wrong, turns out to be our error.

Original NASA ASRS Text

Title: A DORNIER 328 FLC LANDED BELOW MINIMUMS AT CYOW.

Narrative: WE FLEW AN ILS APCH TO RWY 7 AT CYOW AND LANDED WITH LESS THAN REQUIRED VISIBILITY. WE WERE CLRED FOR ILS APCH. WX WAS 300 FT OVCST, VISIBILITY 1 3/4 MI, RVR 3000 FT. APCH CTL STATED CEILING 200 FT OVCST, VISIBILITY 1 1/4 MI, RVR 2000 FT, LIGHTS STAGE 5, CLRED TO LAND. THE CAPT ROGERED THE CALL AND WE CONTINUED APCH. TWR ONCE AGAIN STATED THE SAME WX, 200 FT OVCST, VISIBILITY 1 1/4 MI, RVR 2000 FT, CLRED TO LAND. IN OUR OPS MANUAL THERE IS A CHART FOR OPS IN CANADIAN AIRSPACE ON HOW TO CONVERT METRIC TO RVR AND UNITED STATES VISIBILITY. WE FIGURED CONVERTED RVR FROM 2000 METERS WOULD BE ABOUT 1 1/4 MI, WHICH AGREED WITH TWR RPT OF VISIBILITY IN MI. UPON LNDG WE MENTIONED VISIBILITY SEEMED A LOT LESS THAN 1 1/4 MI. WE DISCUSSED THIS AND CONCLUDED THAT RVR WAS WRONG, TURNS OUT TO BE OUR ERROR.

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.