Near midair collision between air carrier medium large transport and unknown small aircraft.

Attributes
ACN	129314
Time
Date	198910
Day	Fri
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : gve airport : cho
State Reference	VA
Altitude	msl bound lower : 5500 msl bound upper : 5700
Environment
Flight Conditions	VMC
Light	Dusk
Aircraft 1
Operator	common carrier : air carrier
Make Model Name	Medium Large Transport, Low Wing, 2 Turbojet Eng
Flight Phase	descent other
Route In Use	enroute airway : zdc
Flight Plan	IFR
Aircraft 2
Make Model Name	Small Aircraft, Low Wing, 1 Eng, Fixed Gear
Flight Phase	cruise other cruise other
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 210 flight time total : 12000 flight time type : 2000
ASRS Report	129314
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp
Events
Anomaly	conflict : nmac other anomaly other
Independent Detector	other flight crewa
Resolutory Action	flight crew : took evasive action
Consequence	Other
Miss Distance	horizontal : 0 vertical : 200
Supplementary
Primary Problem	Flight Crew Human Performance

Narrative:

Cleared by ZDC to descend to 5000' inbound to cho. Traffic called by first officer at 12:30. Observed traffic for a few seconds as it was not moving in windscreen. Leveled at 5700'. What appeared to be an small aircraft passed directly below at about 5500'. ZDC later painted intermittent raw return as aircraft continued. Other aircraft made no evasive action. I recommend all aircraft be required encoding transponder and required to have it on at all times airborne.

Original NASA ASRS Text

Title: NMAC BETWEEN ACR MLG AND UNKNOWN SMA.

Narrative: CLRED BY ZDC TO DSND TO 5000' INBND TO CHO. TFC CALLED BY F/O AT 12:30. OBSERVED TFC FOR A FEW SECS AS IT WAS NOT MOVING IN WINDSCREEN. LEVELED AT 5700'. WHAT APPEARED TO BE AN SMA PASSED DIRECTLY BELOW AT ABOUT 5500'. ZDC LATER PAINTED INTERMITTENT RAW RETURN AS ACFT CONTINUED. OTHER ACFT MADE NO EVASIVE ACTION. I RECOMMEND ALL ACFT BE REQUIRED ENCODING XPONDER AND REQUIRED TO HAVE IT ON AT ALL TIMES AIRBORNE.

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.