SDR 2022F00412

Service difficulty report · Spacer · Boeing 737

Difficulty date
October 24, 2022
Submitted
October 24, 2022
Operation
General aviation
Make and model
Boeing 737
Part
Spacer
Part number
NAS43DD317N
Part serial
NSN
Condition
Missing
Location
Between Rod Hous
Component
Airstair · Weber
Component part number
87070060X
Stage of operation
IN
How discovered
O
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

DURING OVERHAUL OF AIRSTAIR SN 391, DOW AERO INC WAS PERFORMING OPERATION CHECKS ON THE TEST STAND AND HEARD ABNORMAL NOISES DURING RETRACTION. UPON INSPECTION IT WAS IDENTIFIED THAT A SPACER (NAS43DD3-17N) WAS MISSING WHERE THE ROD/HOUSING ASSEMBLY (811420-3) ATTACHES TO THE LEVER ASSEMBLY (808138-401) ON THE BALLSCREW TRUNNION. INVESTIGATION REVEALED THAT THE CURRENT REVISION OF THE CMM 52-60-10 IPL DOES NOT INCLUDE THE SPACER, THIS SPACER WAS PART OF PREVIOUS REVISIONS BUT WAS EXCLUDED FROM THE CURRENT IPC FOR AN UNKNOWN REASON. THE LACK OF SPACER INSTALLATION CAN CAUSE CONSIDERABLE DAMAGE TO THE CARRIAGE ASSEMBLY. THE SPACER WAS EXCLUDED FROM BOTH THE FORWARD AND AFT BALLSCREW TRUNNION.