B737-800 and LJ25 had near midair collision in N-90 class B.

Attributes
ACN	487711
Time
Date	200010
Day	Thu
Local Time Of Day	1201 To 1800
Place
Locale Reference	navaid : teb.vor
State Reference	NY
Altitude	msl bound lower : 3000 msl bound upper : 4000
Environment
Flight Conditions	IMC
Weather Elements	Rain Fog
Aircraft 1
Controlling Facilities	tower : dfw.tower
Operator	common carrier : air carrier
Make Model Name	B737-800
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
Controlling Facilities	tracon : n90.tracon
Operator	general aviation : corporate
Make Model Name	Learjet 25
Operating Under FAR Part	Part 91
Flight Phase	climbout : vacating altitude climbout : intermediate altitude
Route In Use	departure : on vectors
Flight Plan	IFR
Person 1
Affiliation	government : faa
Function	controller : departure
Qualification	controller : radar
Experience	controller non radar : 2 controller radar : 15
ASRS Report	487711
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Events
Anomaly	altitude deviation : overshoot conflict : airborne critical
Independent Detector	aircraft equipment : tcas other controllera other flight crewa
Resolutory Action	controller : separated traffic controller : issued new clearance controller : issued alert flight crew : returned to assigned altitude other
Miss Distance	vertical : 200
Supplementary
Problem Areas	Airspace Structure Flight Crew Human Performance
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

B737-800 departed ewr issued 4000 ft and 360 degree heading for traffic. Teb departure LJ25 issued 270 degree heading and climb to 6000 ft. When conflict was noticed I issued an amended altitude to LJ25 of 3000 ft. B737-800 was now level at 4000 ft. LJ25 went through 3000 ft and finally stopped at 3500 ft before descending to 3000 ft. B737-800 receives TCASII RA to descend. I cannot understand what went wrong with the TCASII. LJ25 at 3500 ft, B737-800 at 4000 ft approximately 2 mi apart. LJ25 at 3300 ft, B737-800 at 3900 ft, LJ25 at 3100 ft, B737-800 at 3600 ft. LJ25 at 2800 ft, B737-800 at 3000 ft. I immediately issued traffic and for the second time issued a climb to 8000 ft to the B737-800. I forgot to mention that immediately after I stopped the LJ25 at 3000 ft I issued a climb to 8000 ft and a 270 degree heading to the B737-800. The B737-800 never climbed but descended right into the LJ25.

Original NASA ASRS Text

Title: B737-800 AND LJ25 HAD NMAC IN N-90 CLASS B.

Narrative: B737-800 DEPARTED EWR ISSUED 4000 FT AND 360 DEG HDG FOR TFC. TEB DEP LJ25 ISSUED 270 DEG HDG AND CLB TO 6000 FT. WHEN CONFLICT WAS NOTICED I ISSUED AN AMENDED ALT TO LJ25 OF 3000 FT. B737-800 WAS NOW LEVEL AT 4000 FT. LJ25 WENT THROUGH 3000 FT AND FINALLY STOPPED AT 3500 FT BEFORE DSNDING TO 3000 FT. B737-800 RECEIVES TCASII RA TO DSND. I CANNOT UNDERSTAND WHAT WENT WRONG WITH THE TCASII. LJ25 AT 3500 FT, B737-800 AT 4000 FT APPROX 2 MI APART. LJ25 AT 3300 FT, B737-800 AT 3900 FT, LJ25 AT 3100 FT, B737-800 AT 3600 FT. LJ25 AT 2800 FT, B737-800 AT 3000 FT. I IMMEDIATELY ISSUED TFC AND FOR THE SECOND TIME ISSUED A CLB TO 8000 FT TO THE B737-800. I FORGOT TO MENTION THAT IMMEDIATELY AFTER I STOPPED THE LJ25 AT 3000 FT I ISSUED A CLB TO 8000 FT AND A 270 DEG HDG TO THE B737-800. THE B737-800 NEVER CLBED BUT DSNDED R INTO THE LJ25.

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.