Narrative:

This was my fourth trip to ZZZ to company X in the last month regarding my autoplt. About a month ago it was taken down there and the autoplt was removed because of a bad pitch servo. I returned to ZZZ to pick up the aircraft to continue flying it until the part was in that could be replaced. I returned the aircraft to company X on 05/sat/02. Being notified that it was ready to be picked up, I proceeded to ZZZ leaving ZZZ1 at about XA00 the morning of 05/sun/02. At about noon, as I prepared to depart ZZZ, the run up was normal. The autoplt was on in the ready position but not engaged. Electric trim connected to the autoplt was on. As I applied power, the take off appeared normal through rotation. Very shortly after rotation I noticed the airplane was pitching up more than normal and attempted to trim the nose down, I also raised the gear at that point. The aircraft then went into an uncontrollable vertical climb. I continued to exert as much pressure on the yoke to get the nose down as I could, but to no avail. At approximately 500 ft (as estimated by mr. X who was sitting on the ground waiting to take off) with the aircraft being fully vertical, it fell off sharply to the left (a hammerhead movement) and then began to spin to the left. I was able to recover after approximately on half turn by aggressive use of the rudders and pressure on the yoke. The aircraft came out of the spin very close to the earth and immediately began climbing again. At that point, I got my shin onto the yoke to push as hard as I could, heard a pop and then the flight controls were normal. While the aircraft was pitching up vertically, I attempted to disconnect the autoplt by shutting it off, hitting the autoplt disconnect on the yoke, and shutting off the master switch. None of these worked at all. I did not look at any of my flight instruments to determine altitude, rate of climb, airspeed, or any of that, as I was to busy attempting to gain control of the airplane. Callback conversation with reporter revealed the following information: the reporter stated at first it was believed the autoplt was engaged and was commanding the pitch up, but the autoplt was disconnected at takeoff. The reporter stated maintenance found the control cable from the control column to the elevator at the rear of the aircraft to have another cable attached to the control cable called a 'bridal cable.' the reporter said the function of the 'bridal cable' allows input to the elevator from the pitch trim servo electric trim and autoplt. The reporter stated on the pitch trim servo side the cable has a ball stop with a clamp that secures the ball and this clamp was not tightened when installing the pitch trim servo allowing the cable to jam the elevator nose up. The reporter said there have been no recurrent reports on this type of mechanical failure.

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Original NASA ASRS Text

Title: A PIPER AZTEC AFTER ROTATION EXPERIENCED AN UNCONTROLLABLE VERTICAL CLIMB AND AT 500 FT FELL OFF TO THE L AND BEGAN A SPIN TO THE LEFT.

Narrative: THIS WAS MY FOURTH TRIP TO ZZZ TO COMPANY X IN THE LAST MONTH REGARDING MY AUTOPLT. ABOUT A MONTH AGO IT WAS TAKEN DOWN THERE AND THE AUTOPLT WAS REMOVED BECAUSE OF A BAD PITCH SERVO. I RETURNED TO ZZZ TO PICK UP THE ACFT TO CONTINUE FLYING IT UNTIL THE PART WAS IN THAT COULD BE REPLACED. I RETURNED THE ACFT TO COMPANY X ON 05/SAT/02. BEING NOTIFIED THAT IT WAS READY TO BE PICKED UP, I PROCEEDED TO ZZZ LEAVING ZZZ1 AT ABOUT XA00 THE MORNING OF 05/SUN/02. AT ABOUT NOON, AS I PREPARED TO DEPART ZZZ, THE RUN UP WAS NORMAL. THE AUTOPLT WAS ON IN THE READY POS BUT NOT ENGAGED. ELECTRIC TRIM CONNECTED TO THE AUTOPLT WAS ON. AS I APPLIED PWR, THE TAKE OFF APPEARED NORMAL THROUGH ROTATION. VERY SHORTLY AFTER ROTATION I NOTICED THE AIRPLANE WAS PITCHING UP MORE THAN NORMAL AND ATTEMPTED TO TRIM THE NOSE DOWN, I ALSO RAISED THE GEAR AT THAT POINT. THE ACFT THEN WENT INTO AN UNCONTROLLABLE VERTICAL CLIMB. I CONTINUED TO EXERT AS MUCH PRESSURE ON THE YOKE TO GET THE NOSE DOWN AS I COULD, BUT TO NO AVAIL. AT APPROX 500 FT (AS ESTIMATED BY MR. X WHO WAS SITTING ON THE GND WAITING TO TAKE OFF) WITH THE ACFT BEING FULLY VERTICAL, IT FELL OFF SHARPLY TO THE L (A HAMMERHEAD MOVEMENT) AND THEN BEGAN TO SPIN TO THE L. I WAS ABLE TO RECOVER AFTER APPROX ON HALF TURN BY AGGRESSIVE USE OF THE RUDDERS AND PRESSURE ON THE YOKE. THE ACFT CAME OUT OF THE SPIN VERY CLOSE TO THE EARTH AND IMMEDIATELY BEGAN CLIMBING AGAIN. AT THAT POINT, I GOT MY SHIN ONTO THE YOKE TO PUSH AS HARD AS I COULD, HEARD A POP AND THEN THE FLT CTLS WERE NORMAL. WHILE THE ACFT WAS PITCHING UP VERTICALLY, I ATTEMPTED TO DISCONNECT THE AUTOPLT BY SHUTTING IT OFF, HITTING THE AUTOPLT DISCONNECT ON THE YOKE, AND SHUTTING OFF THE MASTER SWITCH. NONE OF THESE WORKED AT ALL. I DID NOT LOOK AT ANY OF MY FLT INSTRUMENTS TO DETERMINE ALTITUDE, RATE OF CLIMB, AIRSPEED, OR ANY OF THAT, AS I WAS TO BUSY ATTEMPTING TO GAIN CTL OF THE AIRPLANE. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE RPTR STATED AT FIRST IT WAS BELIEVED THE AUTOPLT WAS ENGAGED AND WAS COMMANDING THE PITCH UP, BUT THE AUTOPLT WAS DISCONNECTED AT TAKEOFF. THE RPTR STATED MAINT FOUND THE CTL CABLE FROM THE CTL COLUMN TO THE ELEVATOR AT THE REAR OF THE ACFT TO HAVE ANOTHER CABLE ATTACHED TO THE CTL CABLE CALLED A 'BRIDAL CABLE.' THE RPTR SAID THE FUNCTION OF THE 'BRIDAL CABLE' ALLOWS INPUT TO THE ELEVATOR FROM THE PITCH TRIM SERVO ELECTRIC TRIM AND AUTOPLT. THE RPTR STATED ON THE PITCH TRIM SERVO SIDE THE CABLE HAS A BALL STOP WITH A CLAMP THAT SECURES THE BALL AND THIS CLAMP WAS NOT TIGHTENED WHEN INSTALLING THE PITCH TRIM SERVO ALLOWING THE CABLE TO JAM THE ELEVATOR NOSE UP. THE RPTR SAID THERE HAVE BEEN NO RECURRENT RPTS ON THIS TYPE OF MECHANICAL FAILURE.

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.