Narrative:

We were cruising in level flight through the widely used 'northeast practice area,' in preparation for private pilot training maneuvers, when we spotted a red pitts doing a 'falling leaf' aerobatic maneuver 1 mi or so away. We watched the aircraft climb rapidly straight up through our altitude, then fall away. I pointed out to my student our relatively limited evasive abilities, when a high speed aircraft like the pitts is maneuvering. We continued our straight and level flight to the northeast, to clear 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 right. It was approximately 200-300 ft away. There was no communication and no hazard to either aircraft, as the pitts cruised alongside for 20 or 30 seconds, then 'peeled away' up and to the right. My reasons for reporting are several. First, we are seeing increased aerobatic activity like this in congested areas. The aerobatic maneuvering probably should not occur in a heavy 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 aircraft in formation. If we had not seen the aircraft behind and to our right (at about 4 O'clock position) and had rolled into a right turn, a collision would certainly have resulted. Finally, there is an aerobatic box 'several' (there are no dimensions - AFSS) mi northwest of where this interaction occurred. Perhaps the pitts pilot 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 information is just too inaccessible, and locations are too hard to visualize. The pitts pilot would have known that there is an aerobatic box and used it (hopefully). Other pilots less familiar with the local area than myself, including student pilots, 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 north of phoenix, all idented by radial and DME. Every one is a different size. (Besides, most primary training aircraft have no DME.)

Related reports:

Google
 

Original NASA ASRS Text

Title: 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.)

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.