Service difficulty report · Bridge · Let L23SUPERBLAN

Difficulty date
July 27, 2007
Submitted
July 27, 2007
Operation
General aviation
Aircraft
N431BA
Make and model
Let L23SUPERBLAN
Aircraft serial
029013
Aircraft time
1,693 hours
Part
Bridge
Part number
A741210N
Condition
Cracked
Location
Zone 100
Part time
1,693 hours
Stage of operation
NR
How discovered
9
Nature of condition
O
Precautionary procedure
O

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

What was found

ON JULY 23, 2007 DURING A ROUTINE DYE-PENETRANT INSPECTION ON TG-10B (L-23 SUPER BLANIK, S/N 029013) CRACKS WERE DISCOVERED AT SEVERAL WELDS ON THE A741 210N BRIDGE ASSEMBLY. IT IS A MAINTENANCE MANUAL REQUIREMENT THAT THIS PART BE DYE-PENETRANT INSPECTED EVERY 1000 HOURS. A REPLACEMENT BRIDGE ASSEMBLY WAS CANNIBALIZED FROM ANOTHER TG-10B (L23, S/N 029015) IN AN EFFORT TO PLACE THE FIRST NOTED AIRCRAFT BACK IN SERVICE. AS A PRECAUTIONARY STEP, WE DECIDED TO DYE-PENETRANT THE CANNIBALIZED ASSEMBLY AND DISCOVERED IT TOO WAS CRACKED. AT THIS POINT IT WAS DECIDED TO INSPECT THE REST OF THE AIRCRAFT HERE AT USAFA. 12 OUT OF 12 AIRCRAFT REVEALED CRACKS.