737NG ENG FAIL Alert During Normal Shutdown

[JT8D-17]

Hi folks,

I had a bit of a strange one recently.

During taxi to stand we should down engine No.2 as per SOP. When we moved the start lever to CUTOFF the ENG FAIL alert annunciatedand the lower DU “pop up” feature displayed the secondary instruments.

The engineers performed a BITE test but the only fault they found was some minor issues with the engine start switch.

As the conditions for the ENG FAIL alert were not met I am confused as to why this happened. Could the fault with the start switch be the culprit?

Has anyone else ever experienced this?

[tdracer]

Originally Posted by JT8D-17

Hi folks,

I had a bit of a strange one recently.

During taxi to stand we should down engine No.2 as per SOP. When we moved the start lever to CUTOFF the ENG FAIL alert annunciatedand the lower DU “pop up” feature displayed the secondary instruments.

The engineers performed a BITE test but the only fault they found was some minor issues with the engine start switch.

As the conditions for the ENG FAIL alert were not met I am confused as to why this happened. Could the fault with the start switch be the culprit?

Has anyone else ever experienced this?

I'm not familiar with the specifics of the 737NG ENG FAIL message, but the ENG FAIL logic has an input for the fuel switch position - the message obviously being inhibited when the switch is in CUTOFF. Educated guess is that the fault with the switch was the input to the ENG FAIL logic such that the logic thought the fuel switch was still in RUN.

[JT8D-17]

The minor fault was with the engine start switch which is not included in the logic for the ENG FAIL message according to the FCOM. The start lever which is included in the logic was operating normally.

It's very possible that the start switch issue has something to do with it however I had been flying the same aircraft for a few days before and had no issues. The BITE test indicated that the fault had been there a while.