Narrative:

My student made the initial call-up to enter the class D airspace and enter the traffic pattern to runway 25L from the southwest. We were cleared to continue and instructed to report downwind. As we entered the downwind to runway 25L from the 45 degree, my student reported as instructed. Shortly thereafter, tower reported, 'traffic, helicopter, 1 O'clock position, 1000 ft, was traveling wbound, but apparently has decided to travel northbound....' (there was some noise on the frequency and unknown if it was related to this incident.) I looked at the heading indicator and confirmed that the helicopter's direction of travel was nearly at 90 degree intercept angle. I looked over to my right, took the controls and lifted (banked) the right wing up. I saw a helicopter immediately to my right and forward, heading directly toward us. I saw the left side and belly of the 'jet ranger' type helicopter, indicating that it was ahead and slightly above our altitude. I immediately pulled power and forcibly pitched the plane down and to the right. I saw the helicopter continue northbound above us with no evasive action taken by the pilot. After the helicopter passed, which was immediate, I then brought the plane back up to tpa (which is 1000 ft). My student continued the approach and landing without further event. I am positive that had no evasive action been taken by me, the 2 aircraft would have hit. I understand that the helicopter was given clearance to transition the airplane on a certain heading or transition. However, it deviated from it's original course without clearance. The pilot's unanticipated action and deviation from his clearance, as well as lack of situational awareness and procedural knowledge (helicopter tpa is 500 ft and normal transition to the right runway is 2000 ft), as well as his violation of far 91.113 and lack of evasive action contributed greatly to this incident. The controller's authority/authorized to allow the helicopter to transition the airspace at tpa (if, fact) and lack to effectively control the aircraft after the deviation from assigned heading also contributed to this incident. Supplemental information from acn 637167: I was cleared for a long beach airport south to north transition midfield 1000 ft (heading 360 degrees). Few seconds after reporting 'the tank farm, for crossing midfield 1000 ft (approximately 1 NM south of the runway 25L), I saw a cessna at 9 O'clock position on the left downwind, runway 25L, headed 090 degrees at the same altitude and converging fast. I accelerated forward (360 degree heading) maintaining altitude and the cessna dove and turned right (120 heading approximately). We came within 100 ft separation. I didn't receive any traffic warning from the tower. I had a TCASII indication. The TCASII screen was heavily cluttered due to the proximity with the airport and the large number of aircraft in the air and on the ground. It is not uncommon to receive several warnings when crossing over an airport. The TCASII is set off by the aircraft on the ground squawking mode C. I would suggest the tower controller keep traffic outside of their airspace if they feel overloaded or if situational awareness is low or lost. Both pilots and ATC should make sure that the clearance issued is completely understood. The simple technique of the 'readback correct' should improve the situation. Implement alternative transition rtes through congested airspaces that will not interfere with the fixed wing traffic patterns.

Related reports:

Google
 

Original NASA ASRS Text

Title: C152 ENTERING PATTERN FOR LNDG AT LGB EXPERIENCED NMAC WITH HELI TRANSITIONING CLASS D AT 1000 FT.

Narrative: MY STUDENT MADE THE INITIAL CALL-UP TO ENTER THE CLASS D AIRSPACE AND ENTER THE TFC PATTERN TO RWY 25L FROM THE SW. WE WERE CLRED TO CONTINUE AND INSTRUCTED TO RPT DOWNWIND. AS WE ENTERED THE DOWNWIND TO RWY 25L FROM THE 45 DEG, MY STUDENT RPTED AS INSTRUCTED. SHORTLY THEREAFTER, TWR RPTED, 'TFC, HELI, 1 O'CLOCK POS, 1000 FT, WAS TRAVELING WBOUND, BUT APPARENTLY HAS DECIDED TO TRAVEL NBOUND....' (THERE WAS SOME NOISE ON THE FREQ AND UNKNOWN IF IT WAS RELATED TO THIS INCIDENT.) I LOOKED AT THE HDG INDICATOR AND CONFIRMED THAT THE HELI'S DIRECTION OF TRAVEL WAS NEARLY AT 90 DEG INTERCEPT ANGLE. I LOOKED OVER TO MY R, TOOK THE CTLS AND LIFTED (BANKED) THE R WING UP. I SAW A HELI IMMEDIATELY TO MY R AND FORWARD, HEADING DIRECTLY TOWARD US. I SAW THE L SIDE AND BELLY OF THE 'JET RANGER' TYPE HELI, INDICATING THAT IT WAS AHEAD AND SLIGHTLY ABOVE OUR ALT. I IMMEDIATELY PULLED PWR AND FORCIBLY PITCHED THE PLANE DOWN AND TO THE R. I SAW THE HELI CONTINUE NBOUND ABOVE US WITH NO EVASIVE ACTION TAKEN BY THE PLT. AFTER THE HELI PASSED, WHICH WAS IMMEDIATE, I THEN BROUGHT THE PLANE BACK UP TO TPA (WHICH IS 1000 FT). MY STUDENT CONTINUED THE APCH AND LNDG WITHOUT FURTHER EVENT. I AM POSITIVE THAT HAD NO EVASIVE ACTION BEEN TAKEN BY ME, THE 2 ACFT WOULD HAVE HIT. I UNDERSTAND THAT THE HELI WAS GIVEN CLRNC TO TRANSITION THE AIRPLANE ON A CERTAIN HDG OR TRANSITION. HOWEVER, IT DEVIATED FROM IT'S ORIGINAL COURSE WITHOUT CLRNC. THE PLT'S UNANTICIPATED ACTION AND DEV FROM HIS CLRNC, AS WELL AS LACK OF SITUATIONAL AWARENESS AND PROCEDURAL KNOWLEDGE (HELI TPA IS 500 FT AND NORMAL TRANSITION TO THE R RWY IS 2000 FT), AS WELL AS HIS VIOLATION OF FAR 91.113 AND LACK OF EVASIVE ACTION CONTRIBUTED GREATLY TO THIS INCIDENT. THE CTLR'S AUTH TO ALLOW THE HELI TO TRANSITION THE AIRSPACE AT TPA (IF, FACT) AND LACK TO EFFECTIVELY CTL THE ACFT AFTER THE DEV FROM ASSIGNED HDG ALSO CONTRIBUTED TO THIS INCIDENT. SUPPLEMENTAL INFO FROM ACN 637167: I WAS CLRED FOR A LONG BEACH ARPT S TO N TRANSITION MIDFIELD 1000 FT (HDG 360 DEGS). FEW SECONDS AFTER RPTING 'THE TANK FARM, FOR XING MIDFIELD 1000 FT (APPROX 1 NM S OF THE RWY 25L), I SAW A CESSNA AT 9 O'CLOCK POS ON THE L DOWNWIND, RWY 25L, HEADED 090 DEGS AT THE SAME ALT AND CONVERGING FAST. I ACCELERATED FORWARD (360 DEG HDG) MAINTAINING ALT AND THE CESSNA DOVE AND TURNED R (120 HDG APPROX). WE CAME WITHIN 100 FT SEPARATION. I DIDN'T RECEIVE ANY TFC WARNING FROM THE TWR. I HAD A TCASII INDICATION. THE TCASII SCREEN WAS HEAVILY CLUTTERED DUE TO THE PROX WITH THE ARPT AND THE LARGE NUMBER OF ACFT IN THE AIR AND ON THE GND. IT IS NOT UNCOMMON TO RECEIVE SEVERAL WARNINGS WHEN XING OVER AN ARPT. THE TCASII IS SET OFF BY THE ACFT ON THE GND SQUAWKING MODE C. I WOULD SUGGEST THE TWR CTLR KEEP TFC OUTSIDE OF THEIR AIRSPACE IF THEY FEEL OVERLOADED OR IF SITUATIONAL AWARENESS IS LOW OR LOST. BOTH PLTS AND ATC SHOULD MAKE SURE THAT THE CLRNC ISSUED IS COMPLETELY UNDERSTOOD. THE SIMPLE TECHNIQUE OF THE 'READBACK CORRECT' SHOULD IMPROVE THE SIT. IMPLEMENT ALTERNATIVE TRANSITION RTES THROUGH CONGESTED AIRSPACES THAT WILL NOT INTERFERE WITH THE FIXED WING TFC PATTERNS.

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.