SDR CA100604004

Service difficulty report · Relay · Airtrc AT802A

Difficulty date: May 28, 2010
Submitted: January 4, 2011
Operation: Air carrier
Make and model: Airtrc AT802A
Engine: Pwa PT6A67A
System (JASC): 2797 · Flight Control System Wiring
Part: Relay
Condition: Miswired
Location: Flap Control
Stage of operation: IN
How discovered: V
Nature of condition: W
Precautionary procedure: K

As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.

What was found

FLAPS BECAME INTERMITTENT AT ANY POSITION AND SELECTING UP OR DOWN. FLAP MOTOR FOUND TO HAVE DEAD SPOTS ON ARMATURE. WHILE INVESTIGATING FLAP SNAG, IT WAS FOUND THAT THE FLAP UP AND DOWN RELAYS NORMALLY CLOSED AND OPEN CONTACTS WERE OPPOSITE AS SHOWN IN WIRING DIAGRAM. THE FLAP MOTOR SNAG PROBABLY HAS NOTHING TO DO WITH THE RELAY/WIRING ANOMALLY.