A CIRRUS SR20 TVS (TRANSIENT VOLTAGE SUPPRESSOR) CAUGHT FIRE IN FLT. AN EMER WAS DECLARED AND A SAFE LNDG FOLLOWED.

Date: 2008-01 · Aircraft: SR20 · Phase: approach

Anomalies: aircraft-equipment-problem-critical|flight-deck-cabin-aircraft-event-smoke-fire-fumes-odor

Synopsis

A CIRRUS SR20 TVS (TRANSIENT VOLTAGE SUPPRESSOR) CAUGHT FIRE IN FLT. AN EMER WAS DECLARED AND A SAFE LNDG FOLLOWED.

Narrative

SMOKE STARTED COMING OUT OF THE THROTTLE QUADRANT FOLLOWED BY A SHOWER OF SPARKS COMING OUT OF THE CIRCUIT BREAKER PANEL. LOST COM #1; GPS #1; MFD. CALLED TWR ON COM #2 DECLARED EMER AND LANDED SAFE. WE EXPERIENCED A TVS (TRANSIENT VOLTAGE SUPPRESSOR) FAILURE WHICH HAS BEEN OCCURRING TO OTHER CIRRUS AS WELL. OTHER CIRRUS PLTS NEED THIS TO BE BROUGHT TO THEIR ATTN AND CIRRUS CORPORATE NEEDS TO DISTRIBUTE AN AIRWORTHINESS DIRECTIVE OR FIND A FIX FOR THE PROB. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: REPORTER STATED THAT ONCE THE TVS (TRANSIENT VOLTAGE SUPPRESSOR) STOPPED SMOKING THE CABIN STILL HAD A SLIGHT AMOUNT OF SMOKE IN IT. WITH THE TVS FAILURE ALL ELECTRICAL/ELECTRONIC EQUIPMENT EXCEPT COM 2 FAILED. THE FUNCTION OF THE TVS IS TO PROTECT THE EQUIPMENT ON THAT CIRCUIT FROM SURGE AND TRANSIENT VOLTAGE SUCH AS MAY BE CAUSED BY LIGHTNING OR ELECTRICAL GENERATION MALFUNCTIONS. THE REPORTER'S FIXED BASE OPERATOR HAS HAD 3 OF THE SAME FAILURES IN THE PAST YEAR. ADDITIONALLY; THE REPORTER HAS HEARD OF 10 TVS FAILURES SINCE THE SR20'S INTRODUCTION. DURING A SUBSEQUENT CALLBACK THE REPORTER STATED THAT THE FAA; NTSB; AND THE MANUFACTURER ARE ALL WORKING ON THIS ISSUE. WHAT HAS BEEN DETERMINED IS THAT THREE TVS UNITS LOCATED IN A CLUSTER BEHIND A PANEL NEXT TO THE PILOT'S RIGHT THIGH BECOME HEATED; LEADING TO A BLACK RESIN MATERIAL IN THE TVS MELTING. AS THE COMPONENT FAILS; SMOKE AND FOUL SMELLING AIR IS EMITTED. THE FOURTH SINGLE TVS IS LOCATED UNDER THE STBY ATTITUDE INDICATOR OR THE FWD GLARE SHIELD. ALL REPORTED FAILURES TO DATE HAVE BEEN IN THE CENTER CONSOLE IN THE 3 TVS CLUSTER. THE REPORTER'S COMPANY IS CHANGING THE CURRENTLY INSTALLED TVS'S WITH ONES FROM ANOTHER MANUFACTURER AND TO DATE HAVE HAD NO PROBLEMS WITH THE NEW COMPONENTS.

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