CONWAY, SC, USA
N2789P
PIPER PA-18A
BANNER TOW OPNS WERE BEING CONDUCTED. THE PLT TOOK OFF TO MAKE THE 1ST BANNER TOW OF THE DAY. WHEN THE TOW HOOK (GRAPPLING HOOK ON A ROPE) WAS DEPLOYED, THE TOW LINE BCM ENTANGLED IN THE RUDDER CTL & INTERFERED WITH ITS MOVEMENT. ACCORDING TO OPERATOR PSNL, THE PLT SHOULD HAVE VISUALLY CHECKED THE GRAPPLING HOOK LINE AFTER IT WAS DEPLOYED TO ASSURE THAT IT WAS NOT FOULED ON THE RUDDER BELL CRANK; AND IF IT WAS, HE SHOULD HAVE LNDD TO FREE THE LINE, RATHER THAN PICK UP THE BANNER. THE ACFT WAS EQUIPPED WITH A HOOK RELEASE MECHANISM (IAW STC SA 1-349). HOWEVER, THERE WAS EVIDENCE THAT WHEN THE BANNER WAS CAPTURED, ITS WT PLACED TENSION ON THE TOW HOOK LINE & PRECLUDED ITS RLS AS WELL AS CAUSING A DEFLECTED RUDDER. SUBSEQUENTLY, THE ACFT STALLED & SPUN TO THE GND. OPERATOR PSNL RPRTD THAT THE ACFT WOULD HAVE BEEN CONTROLLABLE WITH THE LINE FOULED ON THE RUDDER BELL CRANK. FAA CIRCULAR (AC 43.13-2A) STATED THAT THE SYS SHOULD HAVE BEEN TESTED TO INSURE THERE WAS NO INTERFERENCE WITH THE TAILWHEEL OR ADJACENT STRUCTURE.
TOWLINE INTERFERENCE WITH THE RUDDER, AND FAILURE OF THE PILOT TO MAINTAIN ADEQUATE AIRSPEED, WHICH RESULTED IN A STALL/SPINN. A FACTOR THAT CONTRIBUTED TO THE ACCIDENT WAS: FAILURE OF THE COMPANY/OPERATOR MANAGEMENT TO ADEQUATELY GUARD AGAINST SUCH INTERFERENCE.
Source: NTSB Aviation Accident Database
Aviation Accidents App
In-Depth Access to Aviation Accident Reports