C172 instructor and student had an near midair collision with a twin cessna in ewb class D.

Attributes
ACN	590560
Time
Date	200308
Day	Fri
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : ewb.airport
State Reference	MA
Altitude	msl single value : 1200
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tower : ewb.tower
Operator	general aviation : instructional
Make Model Name	Skyhawk 172/Cutlass 172
Operating Under FAR Part	Part 91
Flight Phase	descent : approach
Route In Use	approach : traffic pattern arrival : vfr
Flight Plan	None
Aircraft 2
Controlling Facilities	tower : ewb.tower
Operator	common carrier : air taxi
Make Model Name	Cessna Twin Piston Undifferentiated or Other Model
Operating Under FAR Part	Part 135
Flight Phase	climbout : intermediate altitude
Person 1
Affiliation	other
Function	instruction : instructor
Qualification	pilot : instrument pilot : private pilot : multi engine pilot : commercial pilot : cfi
Experience	flight time last 90 days : 90 flight time total : 570 flight time type : 525
ASRS Report	590560
Person 2
Affiliation	other
Function	instruction : trainee
Qualification	pilot : instrument pilot : private
Experience	flight time last 90 days : 39 flight time total : 2425 flight time type : 242.5
ASRS Report	590561
Events
Anomaly	conflict : nmac non adherence : published procedure non adherence : far
Independent Detector	other flight crewa other flight crewb
Resolutory Action	flight crew : took evasive action
Miss Distance	horizontal : 500 vertical : 100
Supplementary
Problem Areas	ATC Human Performance Flight Crew Human Performance
Primary Problem	Flight Crew Human Performance

Narrative:

New bedford tower told my student and I to enter left downwind. At approximately 2 mi south of new bedford airport, entering left downwind for runway 23, I saw a twin engine cessna flying straight ahead at us for a head-on collision. The twin cessna was approximately 500 ft in front of us and approximately 50-100 ft above. I immediately pushed the nose forward to have our aircraft do a rapid descent and turned the aircraft to the right to maintain separation and avoid collision.

Original NASA ASRS Text

Title: C172 INSTRUCTOR AND STUDENT HAD AN NMAC WITH A TWIN CESSNA IN EWB CLASS D.

Narrative: NEW BEDFORD TWR TOLD MY STUDENT AND I TO ENTER L DOWNWIND. AT APPROX 2 MI S OF NEW BEDFORD ARPT, ENTERING L DOWNWIND FOR RWY 23, I SAW A TWIN ENG CESSNA FLYING STRAIGHT AHEAD AT US FOR A HEAD-ON COLLISION. THE TWIN CESSNA WAS APPROX 500 FT IN FRONT OF US AND APPROX 50-100 FT ABOVE. I IMMEDIATELY PUSHED THE NOSE FORWARD TO HAVE OUR ACFT DO A RAPID DSCNT AND TURNED THE ACFT TO THE R TO MAINTAIN SEPARATION AND AVOID COLLISION.

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.