Light transport X non adherence to ATC clearance unauthorized runway entry. Pilot deviation.

Attributes
ACN	201673
Time
Date	199202
Day	Fri
Local Time Of Day	0601 To 1200
Place
Locale Reference	atc facility : bos
State Reference	MA
Altitude	agl bound lower : 0 agl bound upper : 0
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Operator	other
Make Model Name	Light Transport, Low Wing, 2 Turbojet Eng
Flight Phase	ground other : taxi
Flight Plan	IFR
Person 1
Affiliation	Other
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 123 flight time total : 8312 flight time type : 2409
ASRS Report	201673
Person 2
Affiliation	Other
Function	flight crew : first officer
Qualification	pilot : instrument pilot : commercial
Events
Anomaly	incursion : runway non adherence : clearance
Independent Detector	other other : unspecified atc
Resolutory Action	none taken : detected after the fact
Consequence	Other
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

Light transport X clearance was to taxi to runway 27 and were to transition to the outer to taxiway charlie and hold short of runway 33L which was being used for takeoff and landing. The conditions were that all runways and taxiways were snow covered and slippery, with light snow and freezing drizzle continuing to fall. With the way the clearance was worded 'transition to the outer' my assumption was that we were on the inner. Taxiing from the general aviation ramp, with the WX conditions as they were it was difficult to see that we were on the outer taxiway already. We turned right at the first intersection and left on what we assumed was the outer taxiway. As it turned out we turned onto runway 4L. This runway was closed due to the WX conditions so there was no conflict with other traffic. I think that if the clearance had been to 'take the outer taxiway' instead of transition to the outer, this incident would not have happened.

Original NASA ASRS Text

Title: LTT X NON ADHERENCE TO ATC CLRNC UNAUTHORIZED RWY ENTRY. PLTDEV.

Narrative: LTT X CLRNC WAS TO TAXI TO RWY 27 AND WERE TO TRANSITION TO THE OUTER TO TAXIWAY CHARLIE AND HOLD SHORT OF RWY 33L WHICH WAS BEING USED FOR TKOF AND LNDG. THE CONDITIONS WERE THAT ALL RWYS AND TAXIWAYS WERE SNOW COVERED AND SLIPPERY, WITH LIGHT SNOW AND FREEZING DRIZZLE CONTINUING TO FALL. WITH THE WAY THE CLRNC WAS WORDED 'TRANSITION TO THE OUTER' MY ASSUMPTION WAS THAT WE WERE ON THE INNER. TAXIING FROM THE GENERAL AVIATION RAMP, WITH THE WX CONDITIONS AS THEY WERE IT WAS DIFFICULT TO SEE THAT WE WERE ON THE OUTER TAXIWAY ALREADY. WE TURNED R AT THE FIRST INTXN AND L ON WHAT WE ASSUMED WAS THE OUTER TAXIWAY. AS IT TURNED OUT WE TURNED ONTO RWY 4L. THIS RWY WAS CLOSED DUE TO THE WX CONDITIONS SO THERE WAS NO CONFLICT WITH OTHER TFC. I THINK THAT IF THE CLRNC HAD BEEN TO 'TAKE THE OUTER TAXIWAY' INSTEAD OF TRANSITION TO THE OUTER, THIS INCIDENT WOULD NOT HAVE HAPPENED.

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.