Small aircraft commenced a circling approach below minimums.

Attributes
ACN	107522
Time
Date	198903
Day	Mon
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : rdg
State Reference	PA
Altitude	agl bound lower : 300 agl bound upper : 500
Environment
Flight Conditions	IMC
Light	Daylight
Aircraft 1
Controlling Facilities	tower : rdg
Operator	general aviation : personal
Make Model Name	Small Aircraft, Low Wing, 1 Eng, Retractable Gear
Flight Phase	cruise other landing : missed approach landing other
Route In Use	arrival other
Flight Plan	IFR
Aircraft 2
Operator	common carrier : air carrier
Make Model Name	Light Transport, High Wing, 2 Turboprop Eng
Flight Phase	ground : holding
Route In Use	departure other
Flight Plan	IFR
Person 1
Affiliation	government : faa
Function	controller : local
Qualification	controller : non radar
ASRS Report	107522
Person 2
Affiliation	Other
Function	flight crew : single pilot
Qualification	pilot : instrument
Events
Anomaly	inflight encounter : weather non adherence : clearance non adherence : far
Independent Detector	other controllera
Resolutory Action	controller : issued new clearance other
Consequence	Other
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

WX: west 3X 3/4 s-f, RVV runway 36 3/8 mi. Small aircraft on ILS runway 36 with approximately 6 KT tailwind. Air carrier light transport taxied into position runway 13 to hold for the small aircraft. With steady snow the light transport was just deiced. I visually picked up small aircraft over numbers of runway 36 approximately 300-500' above runway. At this point the small aircraft started to descend and requested a clearance to circle to runway 13 (he had already initiated a turn). As the small aircraft made his request and started his turn, he had a hot microphone. As I said, we had poor visibility with snow and fog, with obstructions, mountains and other high terrain just north of the field. The decision to circle to runway 13, below circling minimums with the light transport in position on the runway, plus a hot microphone, made this a very dangerous situation. When I finally got through to the small aircraft to execute a missed approach, I advised unable runway 13 due to aircraft in position. He was dangerously low and still dirtied up. Scared the hell out of me, and the hot microphone didn't help.

Original NASA ASRS Text

Title: SMA COMMENCED A CIRCLING APCH BELOW MINIMUMS.

Narrative: WX: W 3X 3/4 S-F, RVV RWY 36 3/8 MI. SMA ON ILS RWY 36 WITH APPROX 6 KT TAILWIND. ACR LTT TAXIED INTO POS RWY 13 TO HOLD FOR THE SMA. WITH STEADY SNOW THE LTT WAS JUST DEICED. I VISUALLY PICKED UP SMA OVER NUMBERS OF RWY 36 APPROX 300-500' ABOVE RWY. AT THIS POINT THE SMA STARTED TO DSND AND REQUESTED A CLRNC TO CIRCLE TO RWY 13 (HE HAD ALREADY INITIATED A TURN). AS THE SMA MADE HIS REQUEST AND STARTED HIS TURN, HE HAD A HOT MIC. AS I SAID, WE HAD POOR VISIBILITY WITH SNOW AND FOG, WITH OBSTRUCTIONS, MOUNTAINS AND OTHER HIGH TERRAIN JUST N OF THE FIELD. THE DECISION TO CIRCLE TO RWY 13, BELOW CIRCLING MINIMUMS WITH THE LTT IN POS ON THE RWY, PLUS A HOT MIC, MADE THIS A VERY DANGEROUS SITUATION. WHEN I FINALLY GOT THROUGH TO THE SMA TO EXECUTE A MISSED APCH, I ADVISED UNABLE RWY 13 DUE TO ACFT IN POS. HE WAS DANGEROUSLY LOW AND STILL DIRTIED UP. SCARED THE HELL OUT OF ME, AND THE HOT MIC DIDN'T HELP.

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.