An air carrier light transport taxied not the active runway using another aircraft's clearance.

Attributes
ACN	272124
Time
Date	199405
Day	Fri
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : mia
State Reference	FL
Altitude	agl bound lower : 0 agl bound upper : 0
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tower : las
Operator	common carrier : air carrier
Make Model Name	Commercial Fixed Wing
Operating Under FAR Part	Part 135
Flight Phase	ground : holding ground other : taxi
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : instrument pilot : commercial pilot : atp
Experience	flight time last 90 days : 180 flight time total : 4900 flight time type : 2500
ASRS Report	272124
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : commercial pilot : instrument
Events
Anomaly	incursion : runway non adherence : clearance
Independent Detector	other controllera other flight crewa
Resolutory Action	controller : issued new clearance flight crew : exited adverse environment
Consequence	Other
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

Aircraft #1 at hold short for runway 27L mia. Tower controller clears aircraft to position and hold. PIC taxied aircraft onto runway but asked first officer to confirm instructions, as the first part of tower transmission blocked by other ATC communications. After contacting tower, discovered that tower had cleared another air carrier be-1900 onto runway. PIC cleared runway and returned to hold short position. No traffic conflicts occurred. Should have confirmed instructions prior to taxiing onto runway, but as we were #1, assumed instructions were for us. Anytime ATC xmissions are partially or fully blocked, get a confirmation from ATC. Never assume -- even when radio volume is heavy.

Original NASA ASRS Text

Title: AN ACR LTT TAXIED NOT THE ACTIVE RWY USING ANOTHER ACFT'S CLRNC.

Narrative: ACFT #1 AT HOLD SHORT FOR RWY 27L MIA. TWR CTLR CLRS ACFT TO POS AND HOLD. PIC TAXIED ACFT ONTO RWY BUT ASKED FO TO CONFIRM INSTRUCTIONS, AS THE FIRST PART OF TWR XMISSION BLOCKED BY OTHER ATC COMS. AFTER CONTACTING TWR, DISCOVERED THAT TWR HAD CLRED ANOTHER ACR BE-1900 ONTO RWY. PIC CLRED RWY AND RETURNED TO HOLD SHORT POS. NO TFC CONFLICTS OCCURRED. SHOULD HAVE CONFIRMED INSTRUCTIONS PRIOR TO TAXIING ONTO RWY, BUT AS WE WERE #1, ASSUMED INSTRUCTIONS WERE FOR US. ANYTIME ATC XMISSIONS ARE PARTIALLY OR FULLY BLOCKED, GET A CONFIRMATION FROM ATC. NEVER ASSUME -- EVEN WHEN RADIO VOLUME IS HVY.

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.