NMAC CAUSED BY UNAUTH FORMATION FLT.

Narrative

WE WERE CRUISING IN LEVEL FLT THROUGH THE WIDELY USED 'NE PRACTICE AREA;' IN PREPARATION FOR PVT PLT TRAINING MANEUVERS; WHEN WE SPOTTED A RED PITTS DOING A 'FALLING LEAF' AEROBATIC MANEUVER 1 MI OR SO AWAY. WE WATCHED THE ACFT CLB RAPIDLY STRAIGHT UP THROUGH OUR ALT; THEN FALL AWAY. I POINTED OUT TO MY STUDENT OUR RELATIVELY LIMITED EVASIVE ABILITIES; WHEN A HIGH SPD ACFT LIKE THE PITTS IS MANEUVERING. WE CONTINUED OUR STRAIGHT AND LEVEL FLT TO THE NE; TO CLR THE AREA BEING USED BY THE PITTS. ABOUT 5 MINS LATER THE PITTS SHOT UP FROM BELOW US; AND JOINED US IN LOOSE FORMATION SLIGHTLY BEHIND US AND TO THE R. IT WAS APPROX 200-300 FT AWAY. THERE WAS NO COM AND NO HAZARD TO EITHER ACFT; AS THE PITTS CRUISED ALONGSIDE FOR 20 OR 30 SECONDS; THEN 'PEELED AWAY' UP AND TO THE R. MY REASONS FOR RPTING ARE SEVERAL. FIRST; WE ARE SEEING INCREASED AEROBATIC ACTIVITY LIKE THIS IN CONGESTED AREAS. THE AEROBATIC MANEUVERING PROBABLY SHOULD NOT OCCUR IN A HVY STUDENT TRAINING AREA LIKE THIS; AS AN E152 COULD NOT EASILY EVADE A FAST AEROBATIC AIRPLANE MANEUVERING OVER SEVERAL MI. SECONDLY; IT IS INCREDIBLY DANGEROUS TO JOIN A NON PARTICIPATING ACFT IN FORMATION. IF WE HAD NOT SEEN THE ACFT BEHIND AND TO OUR R (AT ABOUT 4 O'CLOCK POS) AND HAD ROLLED INTO A R TURN; A COLLISION WOULD CERTAINLY HAVE RESULTED. FINALLY; THERE IS AN AEROBATIC BOX 'SEVERAL' (THERE ARE NO DIMENSIONS - AFSS) MI NW OF WHERE THIS INTERACTION OCCURRED. PERHAPS THE PITTS PLT THOUGHT THAT HE OR SHE WAS IN THE BOX; OR HAD DRIFTED OUT OF IT; WHILE MANEUVERING. IN ANY CASE; THE RISK OF SUCH ENCOUNTERS WOULD BE GREATLY REDUCED IF AEROBATIC BOXES WERE MARKED ON THE SECTIONAL AND CLASS B TERMINAL CHARTS. CURRENT DISSEMINATION OF AEROBATIC BOX INFO IS JUST TOO INACCESSIBLE; AND LOCATIONS ARE TOO HARD TO VISUALIZE. THE PITTS PLT WOULD HAVE KNOWN THAT THERE IS AN AEROBATIC BOX AND USED IT (HOPEFULLY). OTHER PLTS LESS FAMILIAR WITH THE LCL AREA THAN MYSELF; INCLUDING STUDENT PLTS; COULD SEE THE BOX ON THE MAP; AND AVOID IT (WHEN APPROPRIATE). AS OF TODAY; A CALL TO AFSS YIELDS 5 AEROBATIC BOXES WITHIN 30 MI TO THE N OF PHOENIX; ALL IDENTED BY RADIAL AND DME. EVERY ONE IS A DIFFERENT SIZE. (BESIDES; MOST PRIMARY TRAINING ACFT HAVE NO DME.)