BE1900 crew and EMB120 had less than legal separation in ZDC class east airspace.

Attributes
ACN	530099
Time
Date	200111
Day	Thu
Local Time Of Day	1201 To 1800
Place
Locale Reference	navaid : fmn.vortac
State Reference	NM
Altitude	msl single value : 17000
Environment
Flight Conditions	VMC
Weather Elements	Turbulence
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zdv.artcc
Operator	common carrier : air carrier
Make Model Name	Beech 1900
Operating Under FAR Part	Part 121
Flight Phase	cruise : enroute altitude change
Flight Plan	IFR
Aircraft 2
Controlling Facilities	artcc : zdv.artcc
Operator	common carrier : air carrier
Make Model Name	Brasilia EMB-120 All Series
Operating Under FAR Part	Part 121
Flight Phase	climbout : intermediate altitude
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : multi engine pilot : atp
Experience	flight time last 90 days : 240 flight time total : 3100 flight time type : 2300
ASRS Report	530099
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Events
Anomaly	altitude deviation : overshoot conflict : airborne critical inflight encounter : weather inflight encounter : vfr in imc non adherence : required legal separation non adherence : clearance non adherence : far non adherence : published procedure other anomaly other
Independent Detector	aircraft equipment : tcas other flight crewa other flight crewb
Resolutory Action	controller : issued alert flight crew : took evasive action none taken : detected after the fact
Miss Distance	horizontal : 9000 vertical : 400
Supplementary
Problem Areas	ATC Human Performance Flight Crew Human Performance Weather Company
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

I am the captain of flight XXXX, flying from den to fmn. For the descent into fmn, we were originally given 16000 ft MSL and when flight YYYY called for an IFR clearance from dro to den, the ATC controller changed our altitude to 17000 ft and gave flight YYYY an IFR clearance to 16000 ft. Both of us were given TA's for each other and neither of us saw each other visually. We leveled off at 17000 ft and saw flight YYYY on TCASII. Shortly thereafter, the controller asked flight YYYY if they were going to continue their climb in the hold or if they wanted a VFR climb on course. Flight YYYY said that they could accept the VFR climb through 16000 ft. When we reached the dro VOR, we noticed flight YYYY climbing on the TCASII. Their climb continued until they were 400 ft below us on TCASII and approximately 1 1/2 mi. We received a TCASII 'traffic, traffic' at which time my first officer turned left. Our TCASII then showed flight YYYY descending and about 5 seconds later ATC asked them to confirm their altitude at 16000 ft. They said that they were at 16000 ft, although they were getting 'bumps in the clouds.' my understanding is that they should not have been IMC based on their clearance. ATC said nothing further and we did not say anything.

Original NASA ASRS Text

Title: BE1900 CREW AND EMB120 HAD LESS THAN LEGAL SEPARATION IN ZDC CLASS E AIRSPACE.

Narrative: I AM THE CAPT OF FLT XXXX, FLYING FROM DEN TO FMN. FOR THE DSCNT INTO FMN, WE WERE ORIGINALLY GIVEN 16000 FT MSL AND WHEN FLT YYYY CALLED FOR AN IFR CLRNC FROM DRO TO DEN, THE ATC CTLR CHANGED OUR ALT TO 17000 FT AND GAVE FLT YYYY AN IFR CLRNC TO 16000 FT. BOTH OF US WERE GIVEN TA'S FOR EACH OTHER AND NEITHER OF US SAW EACH OTHER VISUALLY. WE LEVELED OFF AT 17000 FT AND SAW FLT YYYY ON TCASII. SHORTLY THEREAFTER, THE CTLR ASKED FLT YYYY IF THEY WERE GOING TO CONTINUE THEIR CLB IN THE HOLD OR IF THEY WANTED A VFR CLB ON COURSE. FLT YYYY SAID THAT THEY COULD ACCEPT THE VFR CLB THROUGH 16000 FT. WHEN WE REACHED THE DRO VOR, WE NOTICED FLT YYYY CLBING ON THE TCASII. THEIR CLB CONTINUED UNTIL THEY WERE 400 FT BELOW US ON TCASII AND APPROX 1 1/2 MI. WE RECEIVED A TCASII 'TFC, TFC' AT WHICH TIME MY FO TURNED L. OUR TCASII THEN SHOWED FLT YYYY DSNDING AND ABOUT 5 SECONDS LATER ATC ASKED THEM TO CONFIRM THEIR ALT AT 16000 FT. THEY SAID THAT THEY WERE AT 16000 FT, ALTHOUGH THEY WERE GETTING 'BUMPS IN THE CLOUDS.' MY UNDERSTANDING IS THAT THEY SHOULD NOT HAVE BEEN IMC BASED ON THEIR CLRNC. ATC SAID NOTHING FURTHER AND WE DID NOT SAY ANYTHING.

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.