RPTR COMPLAINS ABOUT ACFT ON LINE WITH 2 DIFFERENT TYPES OF ENGS; 1 10 PERCENT MORE PWRFUL THAN THE OTHER; THAT COULD CREATE 'VMCG' PROBLEMS IF 1 ENG QUIT AT LOW AIRSPDS.

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DISPATCHED WITH AN INTERMIX OF 22000 AND 20000 POUNDS OF THRUST ENGS. THE BULLETIN STATES 'THERE MAY ALSO BE A PLACARD ON THE FORWARD PANEL BELOW THE ENG INSTS INDICATING WHICH TYPE ENG IS IN EACH LOCATION.' THE INTERMIX WAS INDICATED BY A PLACARD ABOVE EACH SET OF ENG INSTS. APPARENTLY; THE PLACARDS ARE NOT REQUIRED AND THE LOCATION OF THE PLACARD IS OPTIONAL. ALTHOUGH THE BULLETIN STATES 'AVAILABLE THRUST OF BOTH ENGS WILL BE IDENTICAL'; IT WAS NOT SO! ON TKOF AND DURING CLB THROTTLE STAGGER EXCEEDED 2 KNOB WIDTHS. AFTER TKOF I DISCONNECTED THE AUTOTHROTTLES. I WAS ABLE TO OBTAIN SIGNIFICANTLY MORE RPM FROM THE 22000 POUNDS OF THRUST ENG. IF MY MEMORY IS CORRECT; THE RULE OF THUMB IS 'THRUST VARIES WITH THE CUBE OF THE RPM.' THEREFORE; WE COULD HAVE PUSHED THE THROTTLES FULL FORWARD AND OPERATE WITH ASYMMETRICAL THRUST. IN THE EVENT OF AN ENG FAILURE AND APPLICATION OF FULL FORWARD THROTTLE; WE WOULD HAVE BEEN OPERATING A B2 (22000) WITH B1 (20000) FLT DATA. THERE IS A SIGNIFICANT DIFFERENCE BTWN THE VMCG SPD BTWN B1 AND B2 PWRED ACFT. THE TKOF/LNDG DATA CARD WAS FOR A B1 PWRED ACFT. AT LOW TKOF GROSS WTS WITH AN ENG FAILURE OF THE B1 ENG; WE COULD HAVE BEEN OUTSIDE THE OPERATING ENVELOPE FOR THE ACTUAL ENG CONFIGN OF THE ACFT. IS THE BULLETIN INACCURATE? DID MAINT NOT PERFORM THE REQUIRED PROCS TO ENSURE THAT THE ASYMMETRICAL THRUST SITUATION COULD NOT OCCUR. ARE THE MAINT PROCS INADEQUATE? OTHERWISE HOW COULD WE HAVE ENDED UP WITH MORE THAN 2 KNOB WIDTHS OF THROTTLE STAGGER? DOES THE MAINT PROC REQUIRE A FULL PWR RUNUP? IF SO; WHY WASN'T IT ACCOMPLISHED. IF THE MAINT PROCS DO NOT REQUIRE A FULL PWR RUNUP; WHY NOT? CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: RPTR WAS UNABLE TO ADD ANYTHING TO HIS RPT. HE HAS MANY QUESTIONS AND NONE OF THEM HAVE BEEN ANSWERED. THEREFORE; HE WAS UNABLE TO ANSWER ANALYST'S QUESTIONS. HE WONDERED ALOUD IF: IF FULL PWR WAS AVAILABLE TO THE PLT; WHAT WOULD THE VMCG BE AND HOW WOULD THE FLC DETERMINE THE VMCG WHICH WOULD DEPEND ON WHICH ENG FAILED. HE IS VERY CRITICAL OF THE MEL SYS. HE SAID ACFT WAS GNDED ON ARR AT BDL.