Service difficulty report · Starter Gen · Emb EMB505

Difficulty date
January 24, 2026
Submitted
February 23, 2026
Operation
Air carrier
Aircraft
N478QS
Make and model
Emb EMB505
Aircraft serial
50500802
Aircraft time
1,532 hours, 1,205 cycles
Part
Starter Gen
Part number
400SG180Q6
Part serial
S02119XL
Condition
Faulty
Stage of operation
CR
How discovered
V
Nature of condition
J, S
Precautionary procedure
A, G, I

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

What was found

WHILE IN CRUISE A GEN 1 OFF CAS APPEARED. WHILE STARTING TO WORK THROUGH QRH, STARTED GETTING A RAPIDLY CHANGING LIST OF CAS MESSAGES & ERRONEOUS INDICATIONS SUCH AS FLUCTUATING ROLL TRIM SETTINGS EVEN THOUGH ACTUAL TRIM FELT THE SAME. OTHER MESSAGES INCLUDED A TRIM & FLAP FAIL WITH YELLOW X OVER THEIR INDICATIONS. THE ACFT THEN STARTED TO DEPRESSURIZE & WENT INTO ELECTRICAL EMERGENCY WITH A RED CORRESPONDING CAS DISPLAYED. ALL PAX O2 MASKS DEPLOYED. EVENTUALLY RESET GEN 1 & IT CAME BACK ONLINE. AFTER COMING ONLINE THE ACFT STARTED REVERTING BACK TO NORMAL & MADE A NORMAL LANDING. COMPLIED WITH INSTRUCTIONS OF ETD-2026-P300-025381223 REV A BY PERFORMING THE REBUILDING OF ALL THE CONNECTORS DESCRIBED IN PART A WITH NEW PINS AND SOCKETS AS REQUIRED, COMPLIED WITH PART B - SPLICES REBUILD BY REPLACEMENT OF LISTED SPLICES WITH NEW SPLICES. COMPLIED WITH PART C BY REPLACEMENT OF ALL GROUND STUDS AND SHUNTS LISTED WITH NEW UNITS. PERFORMED ALL THE ELECTRICAL CHECKS DESCRIBED IN PART D AND FOUND CHECKS SATISFACTORY. COMPLIED WITH THE REPLACEMENT OF ALL THE WIRES DESCRIBED IN PART E WITH NEW WIRES. PERFORMED ALL REQUIRED TESTS AND OPS CHKS IAW PART F & FOUND SAME SATISFACTORY. COMPLIED WITH PART G BY THE REPLACEMENT OF ALL LISTED PARTS, LT SHUNT, ELECTRICAL TERMINAL WOO73, LPDU, EPDU, GCU 1 WITH NEW UNITS, GCU 2 WITH A REPAIRED UNIT & LT STARTER GEN WITH AN OVERHAULED UNIT. SWAPPED GIA 1 & GIA 2 AND GEA 1 AND GEA 2 PER PART H OF ETD. ALL MAINTENANCE PERFORMED IAW THE APPLICABLE SECTIONS OF AMM AS LISTED IN ETD 2026-P300-025381223. PERFORMED OPS CHK OF WINDSHIELD HEATING SYSTEM IAW AMM 30-42-00. NO DEFECTS NOTED. PERFORMED MANUAL PASSENGER OXYGEN SYSTEM MODE OPERATIONAL CHECK IAW P300 AMM 35-21-00, NO DEFECTS NOTED. PERFORMED AUTOMATIC PASSENGER OXYGEN SYSTEM MODE FUNCTIONAL CHECK IAW AMM 35-21-00, FOUND ALTITUDE PRESSURE SWITCH TO BE DEFECTIVE. REMOVED AND REPLACED DEFECTIVE ALTITUDE PRESSURE SWITCH IAW AMM 35-01-07-400-801-A PERFORMED SATISFACTORY AIRCRAFT PRESSURIZATION CHECK IAW AMM 21-31-00. NO DEFECTS NOTED. ORIGINAL SUBMISSION DATE: 1-28-2026.

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