VFR C172 departure from ads experienced near midair collision at 1300 with unreported opposite direc...

Narrative:

Departing ads runway 15; we were cleared for takeoff with a northeast departure. On departure; we climbed runway heading to about 1;100 ft MSL then initiated a left hand climbing turn to the northeast approximately heading 030 degrees. After rolling out on approximately 030 degree heading; we sighted an aircraft at our altitude heading directly at us. We initiated an abrupt left hand diving turn to avoid traffic. Traffic passed behind us approximately 200 ft. We immediately asked tower why we were not advised of the traffic. Tower said they were not receiving altitude on our transponder and to identify; which we did. I did notice the transponder in 'altitude' mode as well as reporting an altitude; but student flying reached over to confirm was active. Soon after; ads tower seemed to try to sort out traffic. I believe there was a traffic watch aircraft cleared through the class D surface area I believe from east to west as well as another aircraft cleared to a downwind departure. Traffic arriving into addison are usually asked to maintain 2;000 ft MSL. We are unsure of which aircraft was associated with the near miss. Tower did have a trainee working tower frequency.

Original NASA ASRS Text

Title: VFR C172 departure from ADS experienced NMAC at 1300 with unreported opposite direction traffic; controller indicated no Mode-C received from Reporter's aircraft.

Narrative: Departing ADS Runway 15; we were cleared for takeoff with a northeast departure. On departure; we climbed runway heading to about 1;100 FT MSL then initiated a left hand climbing turn to the northeast approximately heading 030 degrees. After rolling out on approximately 030 degree heading; we sighted an aircraft at our altitude heading directly at us. We initiated an abrupt left hand diving turn to avoid traffic. Traffic passed behind us approximately 200 FT. We immediately asked Tower why we were not advised of the traffic. Tower said they were not receiving altitude on our transponder and to identify; which we did. I did notice the transponder in 'altitude' mode as well as reporting an altitude; but student flying reached over to confirm was active. Soon after; ADS Tower seemed to try to sort out traffic. I believe there was a traffic watch aircraft cleared through the Class D surface area I believe from east to west as well as another aircraft cleared to a downwind departure. Traffic arriving into Addison are usually asked to maintain 2;000 FT MSL. We are unsure of which aircraft was associated with the near miss. Tower did have a trainee working Tower frequency.

Data retrieved from NASA's ASRS site as of April 2012 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.

Attributes
ACN	819606
Time
Date	200901
Local Time Of Day	0601-1200
Place
Locale Reference	ADS.Airport
State Reference	TX
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Make Model Name	Skyhawk 172/Cutlass 172
Operating Under FAR Part	Part 91
Flight Phase	Climb
Flight Plan	None
Aircraft 2
Flight Phase	Cruise
Person 1
Function	Pilot Flying
Qualification	Flight Crew Instrument Flight Crew Flight Instructor Flight Crew Commercial
Experience	Flight Crew Last 90 Days 200 Flight Crew Total 1300 Flight Crew Type 10000
Events
Anomaly	Conflict NMAC
Miss Distance	Horizontal 200 Vertical 0

VFR C172 departure from ads experienced near midair collision at 1300 with unreported opposite direction traffic; controller indicated no mode-C received from reporter's aircraft.