Small aircraft lands on highway when caught by IMC WX in mountainous terrain.

Attributes
ACN	241448
Time
Date	199305
Day	Sun
Local Time Of Day	0601 To 1200
Place
Locale Reference	atc facility : w99
State Reference	WV
Altitude	msl bound lower : 4500 msl bound upper : 4500
Environment
Flight Conditions	Marginal
Light	Daylight
Aircraft 1
Controlling Facilities	tower : ckb
Operator	general aviation : personal
Make Model Name	Small Aircraft, High Wing, 1 Eng, Fixed Gear
Flight Phase	cruise other
Flight Plan	None
Person 1
Affiliation	Other
Function	flight crew : single pilot
Qualification	pilot : private
Experience	flight time total : 320
ASRS Report	241448
Person 2
Affiliation	government : faa
Function	controller : local
Qualification	controller : non radar
Events
Anomaly	inflight encounter : weather
Independent Detector	other flight crewa
Resolutory Action	other
Consequence	Other
Supplementary
Primary Problem	Weather
Air Traffic Incident	Pilot Deviation

Narrative:

After receiving a favorable WX brief for a VFR flight from anp to I77, I departed anp with 6 hours (auxiliary tanks) of fuel. After passing kessel VOR I noticed deteriorating WX conditions and raised clarksburg tower to obtain local WX observations (I was 32 KTS east of ckb). Was advised conditions VFR at airport, however, reports of light scattered rain showers. Conditions continued to deteriorate with severe turbulence in area. I initiated a 180 degree turn due east and noticed WX deteriorating to east as well. In light of WX situation and severe turbulence (mountain effect) I thought it prudent to land the aircraft as soon as practicable. Determined closest airport to be W99 (13 KTS 170 degrees), however, did not feel comfortable with present WX. Discovered approximately 4000 ft straight stretch of highway 93 (e-w) and safely landed. I contacted elkins flight service and reported difficulties. I discussed situation with baltimore FSDO and determined that I would depart highway route 93 and land W99 once conditions improved. Conditions improved and I flew safely from highway to W99 (security officers from wv electric secured both ends of highway to permit safe departures). Recommend advising pilots transitioning over mountainous terrain in area of local (elkins) of 'micro-meteorological' conditions unique to this area.

Original NASA ASRS Text

Title: SMA LANDS ON HWY WHEN CAUGHT BY IMC WX IN MOUNTAINOUS TERRAIN.

Narrative: AFTER RECEIVING A FAVORABLE WX BRIEF FOR A VFR FLT FROM ANP TO I77, I DEPARTED ANP WITH 6 HRS (AUX TANKS) OF FUEL. AFTER PASSING KESSEL VOR I NOTICED DETERIORATING WX CONDITIONS AND RAISED CLARKSBURG TWR TO OBTAIN LCL WX OBSERVATIONS (I WAS 32 KTS E OF CKB). WAS ADVISED CONDITIONS VFR AT ARPT, HOWEVER, RPTS OF LIGHT SCATTERED RAIN SHOWERS. CONDITIONS CONTINUED TO DETERIORATE WITH SEVERE TURB IN AREA. I INITIATED A 180 DEG TURN DUE E AND NOTICED WX DETERIORATING TO E AS WELL. IN LIGHT OF WX SIT AND SEVERE TURB (MOUNTAIN EFFECT) I THOUGHT IT PRUDENT TO LAND THE ACFT AS SOON AS PRACTICABLE. DETERMINED CLOSEST ARPT TO BE W99 (13 KTS 170 DEGS), HOWEVER, DID NOT FEEL COMFORTABLE WITH PRESENT WX. DISCOVERED APPROX 4000 FT STRAIGHT STRETCH OF HWY 93 (E-W) AND SAFELY LANDED. I CONTACTED ELKINS FLT SVC AND RPTED DIFFICULTIES. I DISCUSSED SIT WITH BALTIMORE FSDO AND DETERMINED THAT I WOULD DEPART HWY RTE 93 AND LAND W99 ONCE CONDITIONS IMPROVED. CONDITIONS IMPROVED AND I FLEW SAFELY FROM HWY TO W99 (SECURITY OFFICERS FROM WV ELECTRIC SECURED BOTH ENDS OF HWY TO PERMIT SAFE DEPS). RECOMMEND ADVISING PLTS TRANSITIONING OVER MOUNTAINOUS TERRAIN IN AREA OF LCL (ELKINS) OF 'MICRO-METEOROLOGICAL' CONDITIONS UNIQUE TO THIS AREA.

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.