LTT AT CRUISE HAS ACFT TURNING R WHEN ON AUTOPLT. FIND CTLS JAMMED. DSND DIVERT.

Date: 1994-09 · Aircraft: Brasilia EMB-120 All Series

Anomalies: aircraft-equipment-problem-critical|other-unspecified

Synopsis

LTT AT CRUISE HAS ACFT TURNING R WHEN ON AUTOPLT. FIND CTLS JAMMED. DSND DIVERT.

Narrative

AT CRUISE WE NOTICED THE AIRPLANE TURNING TO THE R ON ITS OWN. WE DISCONNECTED THE AUTOPLT; THE CTLS WERE STIFF. IT TOOK BOTH OF US TO CTL THE AIRPLANE. AT THIS POINT WE REALIZED WE HAD JAMMED CTLS. WE DECIDED TO DSND TO GET OUT OF FREEZING CONDITIONS. AT 14500 APPROX ALL OF A SUDDEN IT BROKE FREE. THEN THE CTLS WORKED. WE DECIDED AT THIS POINT WE WOULD DIVERT TO TOL. EVERYTHING FROM THERE ON OUT WAS OKAY. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: RPTR STATES THERE WAS A MAINT CHK ONCE ON THE GND AND MECHANIC BELIEVES THIS WAS CAUSED BY A BINDING STRAP WHICH DISPERSES STATIC ELECTRICITY TO THE STATIC WICKS FOR DISCHARGE. THE STRAP CONSISTS OF SEVERAL STRANDS OF WIRE BOUND TOGETHER AND THIS PARTICULAR ONE WAS EXTRA LONG AND BECAME BOUND UP IN THE CTLS. THE STRAP CONNECTS WING AND AILERON AND IS SEATED IN A SMALL GROOVE IN THE AILERON AND WING. THIS MAKES IT VERY DIFFICULT TO SEE. RPTR TALKED ABOUT THE PROB WITH COMPANY SAFETY REPRESENTATIVE; CHIEF PLT AND DIRECTOR OF MAINT. THEY ARE NOT 100 PERCENT SURE THIS IS THE PROB BUT IT SEEMS TO BE THE MOST PROBABLE AS THE STRAP WAS QUITE FRAYED AND ONLY A COUPLE OF THE WIRES WERE STILL TOGETHER. THE ACFT WAS AN EMB 120. THE FLC DID DECLARE AN EMER. THE REASON THE FIRST THOUGHT WAS OF ICING IS BECAUSE THE ACFT HAD CLBED THROUGH THE FREEZING LEVEL AND HAD A SMALL AMOUNT OF RIME ICE BUILD UP THE ACFT.

Source: NASA Aviation Safety Reporting System (public domain). Reports are voluntary submissions and are not verified by NASA.