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Embraer Phenom 300: Emergency Light Power Supplies

July 2023

Smoking on an aircraft is prohibited by the FAA. This applies to the components on an aircraft as well. However, some of the Emergency Light Power Supplies (ELPS) on the Phenom 300 aircraft are not in compliance with this rule. The charging circuit in the ELPS, P/N 5434-00 and 6434-00, could allow a higher current than would be expected due to short circuits in the battery cells.

Excessive current builds heat, eventually causing the circuit to smoke and becoming noticeable in the cabin.
While it is noted that this issue does not cause a problem or failure in any other system, it may result in delayed or missed flights or an emergency landing.

Scheduled preventative maintenance may help discover the short circuits. However. failures have occurred between the scheduled maintenance periods.

The solution is Service Bulletin 505-33-0007 that replaces the ELPS with one that has an improved charging circuit. The new ELPS P/N 6450LS-00 has an improved circuit that avoids higher current draw and subsequent circuit failure.
Depending on your aircraft serial number, the time of replacement and conditions of replacement, the new ELPS may be provided under warranty terms.

Consult SB 505-33-0007 for more information.