SA227 flight crew receives WX below takeoff minimums near V1 during takeoff roll at lax.

Attributes
ACN	449300
Time
Date	199909
Day	Mon
Local Time Of Day	0001 To 0600
Place
Locale Reference	airport : lax.airport
State Reference	CA
Altitude	agl single value : 0
Environment
Flight Conditions	IMC
Light	Dawn
Aircraft 1
Operator	common carrier : air taxi
Make Model Name	SA-227 AC Metro III
Operating Under FAR Part	Part 135
Flight Phase	ground : takeoff roll
Flight Plan	IFR
Person 1
Affiliation	company : air taxi
Function	flight crew : captain oversight : pic
Qualification	pilot : cfi pilot : atp
Experience	flight time last 90 days : 78 flight time total : 18423 flight time type : 298
ASRS Report	449300
Person 2
Affiliation	company : air taxi
Function	flight crew : first officer
Qualification	pilot : multi engine pilot : instrument pilot : commercial
Events
Anomaly	non adherence : far non adherence : clearance
Independent Detector	other flight crewa other flight crewb
Resolutory Action	none taken : insufficient time
Supplementary
Problem Areas	ATC Human Performance Flight Crew Human Performance
Primary Problem	Ambiguous

Narrative:

Runways 25L&right were reporting 1/2 mi visibility (RVR 2500 ft) which was below part 135 takeoff minimums, but runways 24L&right were reporting RVR 5000 ft, which was ok for part 135 takeoff. After start-up, I asked the first officer if runway 24L&right was still reporting an RVR of 5000 ft. First officer stated that he checked ATIS and that both runways 24L&right were reporting an RVR of 5000 ft. First officer then requested taxi clearance and were assigned runway 25L. Believing that runway 25L had an RVR of 5000 ft, I accepted that runway. After taxiing onto runway 25L and cleared for takeoff, I applied takeoff power and as I reached V1 and was rotating, the tower gave us an RVR of 2500 ft. Already committed to fly, I elected to continue the takeoff instead of aborting.

Original NASA ASRS Text

Title: SA227 FLC RECEIVES WX BELOW TKOF MINIMUMS NEAR V1 DURING TKOF ROLL AT LAX.

Narrative: RWYS 25L&R WERE RPTING 1/2 MI VISIBILITY (RVR 2500 FT) WHICH WAS BELOW PART 135 TKOF MINIMUMS, BUT RWYS 24L&R WERE RPTING RVR 5000 FT, WHICH WAS OK FOR PART 135 TKOF. AFTER START-UP, I ASKED THE FO IF RWY 24L&R WAS STILL RPTING AN RVR OF 5000 FT. FO STATED THAT HE CHKED ATIS AND THAT BOTH RWYS 24L&R WERE RPTING AN RVR OF 5000 FT. FO THEN REQUESTED TAXI CLRNC AND WERE ASSIGNED RWY 25L. BELIEVING THAT RWY 25L HAD AN RVR OF 5000 FT, I ACCEPTED THAT RWY. AFTER TAXIING ONTO RWY 25L AND CLRED FOR TKOF, I APPLIED TKOF PWR AND AS I REACHED V1 AND WAS ROTATING, THE TWR GAVE US AN RVR OF 2500 FT. ALREADY COMMITTED TO FLY, I ELECTED TO CONTINUE THE TKOF INSTEAD OF ABORTING.

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.