C152 and mooney have near midair collision at 300 ft on final at dab.

Attributes
ACN	456208
Time
Date	199912
Day	Thu
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : dab.airport
State Reference	FL
Altitude	agl single value : 300
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tower : dab.tower
Operator	general aviation : instructional
Make Model Name	Cessna 152
Operating Under FAR Part	Part 91
Navigation In Use	other
Flight Phase	landing other
Route In Use	approach : traffic pattern
Flight Plan	None
Aircraft 2
Controlling Facilities	tower : dab.tower
Operator	general aviation : instructional
Make Model Name	M-20 J (201)
Operating Under FAR Part	Part 91
Navigation In Use	other
Flight Phase	landing other
Route In Use	approach : traffic pattern
Person 1
Affiliation	other
Function	instruction : instructor oversight : pic
Qualification	pilot : cfi pilot : commercial pilot : instrument pilot : multi engine
Experience	flight time last 90 days : 75 flight time total : 900 flight time type : 300
ASRS Report	456208
Person 2
Affiliation	other
Function	instruction : trainee
Qualification	pilot : student
Events
Anomaly	conflict : nmac non adherence : clearance non adherence : required legal separation
Independent Detector	other flight crewa
Resolutory Action	controller : separated traffic flight crew : took evasive action
Miss Distance	horizontal : 0 vertical : 50
Supplementary
Problem Areas	ATC Human Performance Flight Crew Human Performance
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Operational Error

Narrative:

I was 'cleared to land' #2 behind a seneca. I was instructed to follow my traffic. The seneca was clearing the runway while I was on final. All of a sudden, a mooney descended from above and came within 50 ft vertically of hitting my aircraft. I assumed control from my student and pushed the nose down. I excitedly told ATC that a mooney was descending on top of us. The controller seemed confused since he called for a 'twin on final to go around.' there was no twin. I informed him the aircraft was a mooney and finally the call was made. We landed without further incident. The best guess my student and I can come up with as to the cause is the mooney turned an early base without having me in sight. Our cessna is high winged and the mooney is low winged. The blind spots made it hard for both of us to see each other. ATC lost situational awareness as to the location of aircraft in the traffic pattern and became confused when the situation occurred.

Original NASA ASRS Text

Title: C152 AND MOONEY HAVE NMAC AT 300 FT ON FINAL AT DAB.

Narrative: I WAS 'CLRED TO LAND' #2 BEHIND A SENECA. I WAS INSTRUCTED TO FOLLOW MY TFC. THE SENECA WAS CLRING THE RWY WHILE I WAS ON FINAL. ALL OF A SUDDEN, A MOONEY DSNDED FROM ABOVE AND CAME WITHIN 50 FT VERTLY OF HITTING MY ACFT. I ASSUMED CTL FROM MY STUDENT AND PUSHED THE NOSE DOWN. I EXCITEDLY TOLD ATC THAT A MOONEY WAS DSNDING ON TOP OF US. THE CTLR SEEMED CONFUSED SINCE HE CALLED FOR A 'TWIN ON FINAL TO GO AROUND.' THERE WAS NO TWIN. I INFORMED HIM THE ACFT WAS A MOONEY AND FINALLY THE CALL WAS MADE. WE LANDED WITHOUT FURTHER INCIDENT. THE BEST GUESS MY STUDENT AND I CAN COME UP WITH AS TO THE CAUSE IS THE MOONEY TURNED AN EARLY BASE WITHOUT HAVING ME IN SIGHT. OUR CESSNA IS HIGH WINGED AND THE MOONEY IS LOW WINGED. THE BLIND SPOTS MADE IT HARD FOR BOTH OF US TO SEE EACH OTHER. ATC LOST SITUATIONAL AWARENESS AS TO THE LOCATION OF ACFT IN THE TFC PATTERN AND BECAME CONFUSED WHEN THE SIT OCCURRED.

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.