Taxi onto active runway, snow.

Attributes
ACN	105224
Time
Date	198902
Day	Mon
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : slc
State Reference	UT
Altitude	agl bound lower : 0 agl bound upper : 0
Environment
Flight Conditions	VMC
Light	Dusk
Aircraft 1
Operator	general aviation : personal
Make Model Name	Small Transport, Low Wing, 2 Recip Eng
Flight Phase	ground other : taxi
Flight Plan	IFR
Person 1
Affiliation	Other
Function	flight crew : single pilot
Qualification	pilot : instrument pilot : private
Experience	flight time last 90 days : 50 flight time total : 3500 flight time type : 1000
ASRS Report	105224
Person 2
Affiliation	government : faa
Function	controller : ground
Qualification	controller : non radar
Events
Anomaly	incursion : runway non adherence : clearance
Independent Detector	other flight crewa
Resolutory Action	flight crew : became reoriented
Consequence	Other
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

Ground control cleared me to taxi from ramp to runway 34R. Ramp area, taxiway and runway had varying amounts of snow. Taxiway signs were half covered with snow. I taxied west and turned south on what I thought was the taxiway. After some 50 yards, I thought I saw what appeared to be partially obscured (by snow) threshold markings. I immediately called ground control to confirm whether I was on the taxiway or the runway. After some delay, they verified that I was on the runway. There was a light twin on a two mile final, and I was able to taxi another 50 yards to the final taxiway exit to clear the active. The aircraft on final did not have to take any evasive action. My inadvertently taxiing onto active runway was caused by snow which made it unclear which area was ramp, taxiway, or runway. There appeared to be no other taxiway available to me when I was departing the ramp area which was almost completely covered with snow.

Original NASA ASRS Text

Title: TAXI ONTO ACTIVE RWY, SNOW.

Narrative: GND CTL CLRED ME TO TAXI FROM RAMP TO RWY 34R. RAMP AREA, TXWY AND RWY HAD VARYING AMOUNTS OF SNOW. TXWY SIGNS WERE HALF COVERED WITH SNOW. I TAXIED W AND TURNED S ON WHAT I THOUGHT WAS THE TXWY. AFTER SOME 50 YARDS, I THOUGHT I SAW WHAT APPEARED TO BE PARTIALLY OBSCURED (BY SNOW) THRESHOLD MARKINGS. I IMMEDIATELY CALLED GND CONTROL TO CONFIRM WHETHER I WAS ON THE TXWY OR THE RWY. AFTER SOME DELAY, THEY VERIFIED THAT I WAS ON THE RWY. THERE WAS A LIGHT TWIN ON A TWO MILE FINAL, AND I WAS ABLE TO TAXI ANOTHER 50 YARDS TO THE FINAL TXWY EXIT TO CLR THE ACTIVE. THE ACFT ON FINAL DID NOT HAVE TO TAKE ANY EVASIVE ACTION. MY INADVERTENTLY TAXIING ONTO ACTIVE RWY WAS CAUSED BY SNOW WHICH MADE IT UNCLEAR WHICH AREA WAS RAMP, TXWY, OR RWY. THERE APPEARED TO BE NO OTHER TXWY AVAILABLE TO ME WHEN I WAS DEPARTING THE RAMP AREA WHICH WAS ALMOST COMPLETELY COVERED WITH SNOW.

Data retrieved from NASA's ASRS site as of August 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.