Narrative:

The aircraft was picked up for our first flight of the day at pit. Maintenance had MEL'd the #2 thrust reverser (and performed the required procedures; i.e., securing the #2 thrust reverser), due to the previous crew write-up that it would not stow correctly. There were no other discrepancies and the #2 thrust reverser alert showed on the multi-function display (mfd). On taxi-out during the checklist we were unable to arm the automatic throttle system, but received no alerts for this system and could not determine the cause of its failure. We then opened the throttles manually and continued the flight to cle. On arrival at cle I wrote up the automatic throttles in the maintenance log. Further investigation by maintenance could reveal no automatic throttle discrepancies. We did discover however that at least 1 automatic throttle channel was required for dispatch. While it could not be directly ascertained, we deduced that the #2 thrust reverse problem caused the logic of the computer to deactivate the automatic throttles. Thus, with the #2 thrust reverser inoperative, no automatic throttles were available, and as one was required, we should not have been dispatched. This aircraft is relatively new, 1 yr, with the company and all the bugs and nuances have not been completely worked out. There were no direct mentions of the relationship of these systems in the books. From now on, I intend to look at MEL items in detail, and should any further problems develop they must be considered suspect as interrelated and the MEL checked. Better documentation of maintenance procedures and MEL's should be available to the crew.

Related reports:

Google
 

Original NASA ASRS Text

Title: A STOWED REVERSER RESTRICTS THE AUTO THROTTLE CHANNELS ON AN ACR MLG. ACFT MINIMUM EQUIPMENT LIST DISPATCHED WITH REVERSER STOWED, NOT KNOWING THAT THE DISENABLED AUTO THROTTLE PROBLEM EXISTED IN THIS NEWER FLEET ADDITION. BOTH MAINT AND DISPATCHER UNAWARE, AS WAS THE FLT CREW. REPORTER COMPLAINS OF PUBLICATION DEFICIENCY IN HANDBOOK NOT REFERENCING THIS RELATIONSHIP.

Narrative: THE ACFT WAS PICKED UP FOR OUR FIRST FLT OF THE DAY AT PIT. MAINT HAD MEL'D THE #2 THRUST REVERSER (AND PERFORMED THE REQUIRED PROCS; I.E., SECURING THE #2 THRUST REVERSER), DUE TO THE PREVIOUS CREW WRITE-UP THAT IT WOULD NOT STOW CORRECTLY. THERE WERE NO OTHER DISCREPANCIES AND THE #2 THRUST REVERSER ALERT SHOWED ON THE MULTI-FUNCTION DISPLAY (MFD). ON TAXI-OUT DURING THE CHKLIST WE WERE UNABLE TO ARM THE AUTO THROTTLE SYS, BUT RECEIVED NO ALERTS FOR THIS SYS AND COULD NOT DETERMINE THE CAUSE OF ITS FAILURE. WE THEN OPENED THE THROTTLES MANUALLY AND CONTINUED THE FLT TO CLE. ON ARR AT CLE I WROTE UP THE AUTO THROTTLES IN THE MAINT LOG. FURTHER INVESTIGATION BY MAINT COULD REVEAL NO AUTO THROTTLE DISCREPANCIES. WE DID DISCOVER HOWEVER THAT AT LEAST 1 AUTO THROTTLE CHANNEL WAS REQUIRED FOR DISPATCH. WHILE IT COULD NOT BE DIRECTLY ASCERTAINED, WE DEDUCED THAT THE #2 THRUST REVERSE PROB CAUSED THE LOGIC OF THE COMPUTER TO DEACTIVATE THE AUTO THROTTLES. THUS, WITH THE #2 THRUST REVERSER INOP, NO AUTO THROTTLES WERE AVAILABLE, AND AS ONE WAS REQUIRED, WE SHOULD NOT HAVE BEEN DISPATCHED. THIS ACFT IS RELATIVELY NEW, 1 YR, WITH THE COMPANY AND ALL THE BUGS AND NUANCES HAVE NOT BEEN COMPLETELY WORKED OUT. THERE WERE NO DIRECT MENTIONS OF THE RELATIONSHIP OF THESE SYSTEMS IN THE BOOKS. FROM NOW ON, I INTEND TO LOOK AT MEL ITEMS IN DETAIL, AND SHOULD ANY FURTHER PROBS DEVELOP THEY MUST BE CONSIDERED SUSPECT AS INTERRELATED AND THE MEL CHKED. BETTER DOCUMENTATION OF MAINT PROCS AND MEL'S SHOULD BE AVAILABLE TO THE CREW.

Data retrieved from NASA's ASRS site as of July 2007 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.