Experimental aircraft pilot and a piper twin had an near midair collision in crq class D airspace.

Attributes
ACN	566469
Time
Date	200211
Day	Fri
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : crq.airport
State Reference	CA
Altitude	msl single value : 1200
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tower : crq.tower
Operator	general aviation : personal
Make Model Name	Experimental
Operating Under FAR Part	Part 91
Flight Phase	descent : approach
Route In Use	approach : traffic pattern
Flight Plan	None
Aircraft 2
Controlling Facilities	tower : crq.tower
Operator	general aviation : personal
Make Model Name	Piper Twin Piston Undifferentiated or Other Model
Operating Under FAR Part	Part 91
Flight Phase	descent : approach
Route In Use	approach : traffic pattern
Person 1
Affiliation	other
Function	flight crew : single pilot
Qualification	pilot : cfi pilot : atp pilot : instrument pilot : multi engine
Experience	flight time last 90 days : 109 flight time total : 9873 flight time type : 1218
ASRS Report	566469
Person 2
Affiliation	other
Function	flight crew : single pilot
Events
Anomaly	conflict : nmac non adherence : required legal separation non adherence : published procedure non adherence : far
Independent Detector	other flight crewa
Resolutory Action	flight crew : took evasive action none taken : detected after the fact
Miss Distance	horizontal : 50 vertical : 100
Supplementary
Problem Areas	ATC Human Performance Flight Crew Human Performance Airport
Primary Problem	Flight Crew Human Performance

Narrative:

On a 45 degree entry to runway 24 (right pattern), a piper twin on a semi right crosswind for runway 24 was approximately 100 ft above my pattern altitude. I had to make a rapid descent to not collide with the twin. Note: the tower was very busy handling a variety of aircraft -- jets, twins, experimental. Pattern work was in progress. Believe the twin was doing pattern work and turned too short on right crosswind and turned downwind too soon with so much traffic in pattern. The twin did not make a 90 degree right turn in the pattern but more than and had turned approximately 135 degrees turning directly toward traffic turning in on a 45 degree entry for right downwind. Also: it appears that pattern work should be done on the south side of the airport. Most traffic enters from the north and a possibility of a collision with traffic on the north side.

Original NASA ASRS Text

Title: EXPERIMENTAL ACFT PLT AND A PIPER TWIN HAD AN NMAC IN CRQ CLASS D AIRSPACE.

Narrative: ON A 45 DEG ENTRY TO RWY 24 (R PATTERN), A PIPER TWIN ON A SEMI R XWIND FOR RWY 24 WAS APPROX 100 FT ABOVE MY PATTERN ALT. I HAD TO MAKE A RAPID DSCNT TO NOT COLLIDE WITH THE TWIN. NOTE: THE TWR WAS VERY BUSY HANDLING A VARIETY OF ACFT -- JETS, TWINS, EXPERIMENTAL. PATTERN WORK WAS IN PROGRESS. BELIEVE THE TWIN WAS DOING PATTERN WORK AND TURNED TOO SHORT ON R XWIND AND TURNED DOWNWIND TOO SOON WITH SO MUCH TFC IN PATTERN. THE TWIN DID NOT MAKE A 90 DEG R TURN IN THE PATTERN BUT MORE THAN AND HAD TURNED APPROX 135 DEGS TURNING DIRECTLY TOWARD TFC TURNING IN ON A 45 DEG ENTRY FOR R DOWNWIND. ALSO: IT APPEARS THAT PATTERN WORK SHOULD BE DONE ON THE S SIDE OF THE ARPT. MOST TFC ENTERS FROM THE N AND A POSSIBILITY OF A COLLISION WITH TFC ON THE N SIDE.

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.