A DEPARTING MD90 VIOLATES THE NOISE ABATEMENT SOUND LEVEL AT SNA WHEN THE AUTOTHROTTLE AND GEAR WARNING HORN CUTOFF BUTTON BOTH MALFUNCTION DURING THE INITIAL CLBOUT.

Narrative

DURING TKOF FROM SNA; OUR AUTOTHROTTLES BECAME INOP. THE PROC FOR AN MD90 IS TO REDUCE THRUST AT 800 FT. OUR TKOF EPR WAS 1.51 AND OUR CUTBACK EPR WAS TO BE 1.33. WITH THE AUTOTHROTTLES INOP; I WOULD DO THIS MANUALLY AT 800 FT. WE WERE DOING A PACK OFF 24 DEG FLAP TKOF. THE LNDG GEAR AURAL WARNING GOES OFF IF THE GEAR IS NOT DOWN WHEN THE FLAPS ARE GREATER THAN 23 DEGS. WE HAVE A BUTTON TO SILENCE THE HORN. THE PROC AT SNA IS TO DO THE CUTBACK EPR AT 800 FT; TURN TO 175 DEGS AT 1 DME ON THE SNA LOC. (WE WERE USING RWY 19R) CLB TO 7000 FT WITH AN ALT RESTR AT 5.6 DME. ALSO WITH A PACK OFF TKOF; THE PROC IS TO TURN THE PACKS ON ONE AT A TIME AT 400 FT. THE WORKLOAD IS HIGH AND MADE HIGHER WITH THE PACKS OFF AND AUTOTHROTTLES INOP. AS SOON AS WE TOOK OFF AND RAISED THE GAR; THE GEAR AURAL WARNING WOULD NOT SILENCE. FLAPS ARE NOT RETRACTED UNTIL 2500 FT ON THIS DEP PROC. TWR CALLED AND SAID TO LEVEL NOW AT 3000 FT AND TO CALL DEP. RESETTING THE ALT; CHANGING THE HDG; GETTING THE PACKS BACK ON; DEP TELLING US ABOUT TFC THEN SAYING CLB TO 16000 FT; I MISSED DOING THE MANUAL CUTBACK. DEP CTL THEN SAID TO CLB TO 13000 FT AND TURN IMMEDIATELY TO 120 DEGS. AT THIS POINT I WAS SO FAR BEHIND THE ACFT; I WASN'T SURE THAT WE HADN'T MADE A MISTAKE ON THE ALT CHANGES. DEP CTL SWITCHED US TO ZLA AND WE CONTINUED. I SUSPECT WE EXCEEDED THE NOISE ABATEMENT LEVEL; AND ALTHOUGH DEP NEVER SAID ANYTHING IN MY MIND BY THE THIRD ALT CHANGE I WAS WONDERING IF WE HAD READ BACK THE WRONG ALT WHEN WE CHANGED TO 16000 FT. IT WAS A CASE OF BEING QUICKLY OVERLOADED ON A DEP THAT IS HIGHLY LOADED WHEN ALL IS NORMAL; WHEN ITEMS WERE ADDED TO OUR WORKLOAD.