A B400A IN TKOF CLB WAS UNABLE TO TRIM NOSE DOWN TO 3000 FT ASSIGNED ALT. TRIM FAILED FROM BOTH CTL COLUMN TRIM SWITCHES.

Narrative

THIS IS A CLR CASE OF A MECHANICAL MALFUNCTION. CONDITIONS AT TIME OF DEP: VERY COOL TEMP; NEAR SEA LEVEL AND A VERY LIGHT ACFT. ON DEP; OUR INITIAL RATE OF CLB WAS 4000 FPM. AS I LOWERED THE PITCH AND REDUCED PWR TO LEVEL AT OUR ASSIGNED ALT OF 3000 FT; I NOTICED THAT MY ATTEMPT TO TRIM THE PITCH NOSE DOWN HAD NO EFFECT. I SOON HAD THE CTL YOKE AT THE FULL FORWARD MECHANICAL LIMIT WITH THE PWR REDUCED AS MUCH AS PRACTICAL AND WAS STILL CLBING. I INSTRUCTED THE COPLT TO TRIM NOSE DOWN FROM HIS SIDE AND THAT; TOO; WAS UNSUCCESSFUL. I THEN HAD THE COPLT GO TO EMER TRIM. BY THE TIME WE WERE ABLE TO REGAIN TRIM CTL AND THUS LEVEL THE ACFT; WE HAD CLBED 800 FT ABOVE OUR ASSIGNED ALT. AS A PROFESSIONAL PLT; IT IS TRULY DISAPPOINTING NOT TO COMPLY WITH A CLRNC -- NO MATTER THE REASON. I CAN ASSURE YOU THAT I MADE EVERY REASONABLE EFFORT TO LEVEL THE ACFT AT 3000 FT. AS STATED; THIS WAS A MECHANICAL ISSUE. I'M NOT SURE THERE IS ANYTHING THAT CAN BE DONE TO PREVENT A RECURRENCE. THE ACFT TRIM SYS CONTINUES TO TEST NORMAL. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE RPTR STATED THE CTL HORN TRIM SWITCH SERVES 2 PURPOSES: 1) FUNCTIONS AS A PITCH TRIM SWITCH; AND 2) FUNCTIONS AS AN AILERON TRIM CTL. THE RPTR STATED THE SWITCH CAN BE MOVED UP; DOWN; L; AND R TO PERFORM THE TRIM FUNCTIONS. TO DATE; MAINT HAS NOT BEEN ABLE TO DUPLICATE THE RPT; BUT SUSPECT THE SWITCHES. THE RPTR INDICATED THIS TRIM SYS HAS NO MANUAL BACKUP -- ONLY ELECTRIC FUNCTIONS.