Carj crew had a TCASII event with a grumman aircraft in oma class C airspace.

Attributes
ACN	595416
Time
Date	200309
Day	Sun
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : oma.airport
State Reference	NE
Altitude	msl single value : 3000
Environment
Flight Conditions	IMC
Weather Elements	other
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : r90.tracon tower : oma.tower
Operator	common carrier : air carrier
Make Model Name	Regional Jet 700 ER&LR
Operating Under FAR Part	Part 121
Navigation In Use	other
Flight Phase	climbout : intermediate altitude
Route In Use	departure : on vectors
Flight Plan	IFR
Aircraft 2
Operator	general aviation : personal
Make Model Name	Grumman Corp Undifferentiated or Other Model
Operating Under FAR Part	Part 91
Flight Phase	cruise : level cruise : enroute altitude change
Flight Plan	None
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : multi engine pilot : atp
Experience	flight time total : 18000 flight time type : 4000
ASRS Report	595416
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Events
Anomaly	altitude deviation : excursion from assigned altitude conflict : airborne critical inflight encounter : vfr in imc inflight encounter : weather non adherence : company policies non adherence : far non adherence : published procedure non adherence : required legal separation other anomaly other
Independent Detector	aircraft equipment : tcas other flight crewa other flight crewb
Resolutory Action	controller : issued advisory flight crew : overrode automation flight crew : took evasive action other
Miss Distance	horizontal : 2000 vertical : 500
Supplementary
Problem Areas	ATC Human Performance Company Flight Crew Human Performance
Primary Problem	Flight Crew Human Performance

Narrative:

Possible near midair collision. Oma departing runway 36. Clearance was to level at 3000 ft for traffic. Autoplt was on. Handed off to departure climbing through 2000 ft, we leveled at 3000 ft. Departure issued traffic off our right at 3500 ft and climbing. We reported visual on the grumman aircraft. Our TCASII showed traffic +500 ft, not climbing. Lateral separation was closing. Autoplt was disconnected. (It appeared that the grumman aircraft was skud running -- cloud deck was just above the other aircraft.) ATC issued a visual climb reference, that aircraft, and right turn on course. TCASII issued a command to climb. We did not. A climb would have put us on a collision course with the other aircraft. We started to bank left and descend. TCASII issued 'descend, descend now,' within seconds 'maintain vertical speed' and 'clear of conflict.' there was no further transmission with ATC until conflict was cleared and thought gathered. Our maneuvering of the aircraft was slight. Later, ATC was questioned if any other aircraft were in the area. There was none. Our passenger commented to our flight attendant on the close proximity of the other aircraft. Broken cloud deck may have played a part. TCASII issuing a climb was not expected. A descent is what was anticipated. IOE was in progress. Local controller was working clearance, ground and tower. TCASII was written up upon our arrival at destination.

Original NASA ASRS Text

Title: CARJ CREW HAD A TCASII EVENT WITH A GRUMMAN ACFT IN OMA CLASS C AIRSPACE.

Narrative: POSSIBLE NMAC. OMA DEPARTING RWY 36. CLRNC WAS TO LEVEL AT 3000 FT FOR TFC. AUTOPLT WAS ON. HANDED OFF TO DEP CLBING THROUGH 2000 FT, WE LEVELED AT 3000 FT. DEP ISSUED TFC OFF OUR R AT 3500 FT AND CLBING. WE RPTED VISUAL ON THE GRUMMAN ACFT. OUR TCASII SHOWED TFC +500 FT, NOT CLBING. LATERAL SEPARATION WAS CLOSING. AUTOPLT WAS DISCONNECTED. (IT APPEARED THAT THE GRUMMAN ACFT WAS SKUD RUNNING -- CLOUD DECK WAS JUST ABOVE THE OTHER ACFT.) ATC ISSUED A VISUAL CLB REF, THAT ACFT, AND R TURN ON COURSE. TCASII ISSUED A COMMAND TO CLB. WE DID NOT. A CLB WOULD HAVE PUT US ON A COLLISION COURSE WITH THE OTHER ACFT. WE STARTED TO BANK L AND DSND. TCASII ISSUED 'DSND, DSND NOW,' WITHIN SECONDS 'MAINTAIN VERT SPD' AND 'CLR OF CONFLICT.' THERE WAS NO FURTHER XMISSION WITH ATC UNTIL CONFLICT WAS CLRED AND THOUGHT GATHERED. OUR MANEUVERING OF THE ACFT WAS SLIGHT. LATER, ATC WAS QUESTIONED IF ANY OTHER ACFT WERE IN THE AREA. THERE WAS NONE. OUR PAX COMMENTED TO OUR FLT ATTENDANT ON THE CLOSE PROX OF THE OTHER ACFT. BROKEN CLOUD DECK MAY HAVE PLAYED A PART. TCASII ISSUING A CLB WAS NOT EXPECTED. A DSCNT IS WHAT WAS ANTICIPATED. IOE WAS IN PROGRESS. LCL CTLR WAS WORKING CLRNC, GND AND TWR. TCASII WAS WRITTEN UP UPON OUR ARR AT DEST.

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.