Service difficulty report · Control Unit · Bombdr DHC8402

Difficulty date
May 24, 2019
Submitted
May 28, 2019
Operation
Air carrier
Aircraft
N443QX
Make and model
Bombdr DHC8402
Aircraft serial
4353
Aircraft time
17,846 hours, 19,140 cycles
Part
Control Unit
Part number
35138507002
Part serial
4212
Condition
Malfunctioned
Location
Zone 200
Stage of operation
CL
How discovered
O
Nature of condition
N
Precautionary procedure
A

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

What was found

ON GEAR RETRACTION LEFT MAIN GEAR DOWN INDICATOR REMAINED ILLUMINATED, GEAR DOORS SEQUENCED NORMALLY. CONFERED WITH FA'S THAT GEAR ACTUALLY DID RETRACT. UPON GEAR EXTENSION, LEFT MAIN GEAR DOWN INDICATOR BECAME VERY BRIGHT. GEAR EXTENDED NORMALLY AND CONFURED WITH FSA'S THAT LEFT MAIN WAS DOWN. RETURNED TO FIELD. LANDING UNEVENTFUL. REMOVED FROM SERVICE. INSPECTED LEFT GEAR DOWNLOCK LIGHT ON GEAR SELECTOR PANEL AND FOUND BULB HAD SHORTED TO CONTACTS BEHIND LIGHT LENS. REMOVED BULB AND RELAMPED IAW AMM 32-31-01-960-801. NO HELP. LIGHT REMAINED FULL BRIGHT WHEN BRIGHT/DIM SWITCH WAS SET TO DIM. REMOVED AND REPLACED LANDING GEAR CONTROL PANEL IAW AMM 32-31-01-000-801/400-801. FUNCTIONAL CHECK FAILED ON STEP 4. A. (20) OF AMM 32-31-01-720-801. DISCREPANCY REMAINED: LEFT GEAR DOWNLOCK LIGHT REMAINED FULLY ILLUMINATED WHEN BRIGHT/DIM WAS SET TO DIM. IN REF TO SDS 31-51-00-001 AND WM 32-61-00-1. REMOVED AND REPLACED ACU IAW AMM 31-51-06-000-801/400-801. OPS TEST GOOD. LEFT GEAR DOWNLOCK LIGHT FUNCTIONED CORRECTLY WITH CORRESPONDING BRIGHT/DIM SWITCH POSITION. PERFORMED FUNCTIONAL TEST OF LANDING GEAR CONTROL PANEL IAW AMM 32-31-01-720-801. FUNCTIONAL TEST GOOD. NO FURHTER DEFECTS NOTED. RETURNED TO SERVICE.