Service difficulty report · Housing · Snias AS350B3

Difficulty date
May 8, 2020
Submitted
June 26, 2020
Operation
General aviation
Aircraft
N181FS
Make and model
Snias AS350B3
Aircraft serial
4120
Part
Housing
Part number
900A6044
Part serial
1192
Condition
Cracked
Location
Tailboom
Part time
98 hours
Stage of operation
UK
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

CONDENSER BLOWER FAN PLASTIC SHROUD HOUSING HEAT WARPED AND CRACKED CAUSING FAN BLADE CONTACT WITH THE SHROUD, AND SUBSEQUENT BLOWER FAILURE. THIS FAN ASSEMBLY IS INSTALLED INSIDE THE AIR CONDITIOR'· SYSTEM CONDENSER HOUSING PER STC SR09117RC-D (KIT PIN J5CTA000-2). IT APPEARS THAT THE OPERATING TEMPERATURE THE CONDENSER HOUSING ASSEMBLY EXCEEDS THE TEMPERATURE THRESHOLD C THE PLASTIC/ COMPOSITE MATERIAL THE BLOWER HOUSING IS MADE OF. TRADITIONALLY FANS IN THIS TYPE OF APPLICATION HAVE BEEN MOUNTED EXTERNALLY TO THE CONDENSER THAT WOULRL A,LOW OUTSIDE AIR TO CIRCULATE AROUND THE BLOWER HOUSING TO AID IN COOLING, AND MOST FREQUENTLY HAVE METAL HOUSINGS THAT CAN WITHSTAND MORE HEAT. RECOMMEND AN INSTALLATION REDESIGN MOUNTING THE BLOWER EXLERNALLY ON THE CONDENSERASSEMBLY, AND/ OR MANUFACTURE THE FAN SHROUD HOUSING OUT OF METAL. THIS IF THE SECOND R1 OCCURRENCE OF HEAT WARP AND AND BLOWER FAILURE ORI THIS AIRCRAFT.