INFLT ENG SHUTDOWN ON AN EMB145 OCCURS WHEN PIC ELECTS TO SHUT DOWN THE APU WHILE FOLLOWING THE AFTER TKOF CHKLIST. RETURN AND LAND.

Narrative

I WAS FO ON THE EMB145 AND WAS THE PF; WHEN WE DEPARTED MSP FOR CLE ON JUL/FRI/97. THE TKOF WAS NORMAL AS WAS THE INITIAL CLB THROUGH ACCELERATION HT (500 FT AGL). I CALLED FOR THE AFTER TKOF CHKLIST WHICH WAS COMPLETED BY MY CAPT. THE LAST ITEM ON THIS CHKLIST CALLS FOR A DECISION TO BE MADE ON LEAVING THE APU UP OR DOWN. WE DECIDED TO TURN IT OFF SO CAPT PROCEEDED TO SHUT IT DOWN. VERY SHORTLY AFTERWARDS; THE #1 ENG FAILED ABRUPTLY. WE COMPLETED THE CHKLISTS; SECURED THE FAILED ENG AND RETURNED FOR LNDG AT MSP WITHOUT FURTHER INCIDENT. I BELIEVE WE DID ALL WE COULD TO SAFELY BRING THE PAX BACK TO THE ARPT. AFTER OUR MAINT PERSONNEL EXAMINED THE ENG IN QUESTION; NOTHING WAS FOUND WRONG WITH IT. BOTH CAPT AND I BEGAN TO QUESTION WHAT COULD HAVE BEEN THE CAUSE. WE BOTH SPECULATED THAT DURING THE AFTER TKOF CHKLIST IT MAY HAVE BEEN REMOTELY POSSIBLE THAT THE WRONG SWITCH WAS SELECTED FOR APU SHUTDOWN. I PERSONALLY DID NOT SEE THE SWITCH IN THE WRONG POS AND DON'T BELIEVE THAT IT WAS SELECTED WRONGLY. THE ALLISON ENGS ARE CTLED BY A COMPUTER/FADEC; WHICH COULD HAVE SENSED A FAULT AND AUTOMATICALLY SHUT THE ENG DOWN; BUT NO EVIDENCE OF THIS WAS FOUND. UNFORTUNATELY; SINCE THE EMB145 IS A NEW ACFT; THERE IS NO HISTORY OF THIS TYPE OF EVENT. WE HOPE THE FDR WILL PROVE THAT THE ENG'S COMPUTER DID INDEED HAVE SOME FAULT WHICH OCCURRED AT THAT POINT IN TIME; HOWEVER WE DON'T RULE OUT THE POSSIBILITY OF HUMAN ERROR.