MD-11
Confusion; Training / Qualification; Human-Machine Interface; Distraction
Aircraft Equipment Problem Less Severe
Flight Crew Rejected Takeoff; General Maintenance Action
Aircraft; Logbook Entry
Left the gate with Tail Cone Unlock Alert warning deferred. The doors were verified closed by Maintenance per the MEL. During takeoff at around 40 KTS we got the LVL 2 alert and master caution for the Tail Cone unlock and we rejected the takeoff; ran the Rejected Takeoff checklist; consulted with Maintenance and continued the flight. Subsequent takeoff was uneventful with no warnings for the tail cone unlock.The remarks section of the MEL for this deferral says 'TAIL CONE UNLOCK alert may REMAIN displayed' The alert was never displayed during start up and taxi and I expected the light would stay that way. When I saw it displayed on takeoff I reacted like I would do for any Level 2 alert and Master Caution prior to 80 KTS. I think if the MEL would say something like 'TAIL CONE UNLOCK LIGHT ALERT MAY INTERMITTENTLY DISPLAY DURING ALL PHASES OF FLIGHT' perhaps we would have been able to process the event a lot better.
[The warning] then appeared again upon lowering the gear on approach during another critical phase of flight triggering the master caution and then going away only to reappear every minute or so during the approach until touchdown. This was an ILS approach in visual conditions but still takes attention away for a moment to see and deal with turning the Master Caution off and determining that it was only this known problem. I feel that had it been in IMC conditions for takeoff/approach or even worse a CAT2/3 approach this would have turned into a more problematic distraction during an extremely critical phase of flight.
Recurring warning for the previously deferred 'Tail Cone Unlock Alert Message' caused the flight crew of an MD-11 to reject their takeoff at low airspeed.