MD80 CAPT PROVIDES DOCUMENTARY EVIDENCE THAT THE ALPHA REFERENCE SPD COMPUTED BY THE ACFT OFTEN INDICATES THE ACFT IS SIGNIFICANTLY HEAVIER THAN THE PAPERWORK SHOWS. RPTR FEELS THIS RESULTS IN UNSATISFACTORY PERFORMANCE AND POTENTIAL SAFETY HAZARDS IN PERFORMANCE LIMITED OPERATIONS.

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REFERENCE THE BOEING MD80 ACFT MAINT MANUAL; FROM WHICH I QUOTE; 'AUTO THROTTLE/SPD CTL -- DESCRIPTION AND OPERATION SUBCHAPTER. SECTION 2 K SLOW-FAST DISPLAY (1) THE SLOW-FAST DISPLAY INDICATES SPD DEV RELATIVE TO ALPHA REFERENCE SPD. SECTION 3 AT/SC FUNCTIONAL OPERATION D: COMPUTED WT IS DETERMINED FROM COEFFICIENT OF LIFT; AIRSPD AND WING CONFIGURATION AND IS USED TO ESTABLISH A MINIMUM SAFE REFERENCE SPD. MEASURED ANGLE-OF-ATTACK FROM THE ANGLE-OF-ATTACK SENSOR IS USED DURING TKOF AND GO-AROUND MANEUVERS IN DEVELOPMENT OF FLT DIRECTOR PITCH COMMAND SIGNAL TO ESTABLISH THE PROPER PITCH ATTITUDE TO MAINTAIN A TKOF OR GO-AROUND REFERENCE SPD. H. IT (ALPHA SPD) ACTS AS A REFERENCE FOR STALL SPD AND OPERATIONAL MODES THAT THE ACFT ARE IN. NOTE: IF ALPHA SPD REGISTERS HIGH IN STABILIZED; UNACCELERATED FLT; IT IS OFTEN A VALID INDICATION THAT THE ACFT IS HEAVIER THAN COMPUTED. SECTION 4 C SPD SEL MODE (3) WITH AUTOTHROTTLE ENGAGED IN THE SPD SEL MODE; IF THE ALPHA REFERENCE SPD IS A HIGHER VALUE THAN THE SELECTED SPD; ALFA SPD WILL BE DISPLAYED ON THE ATIS MODE ANNUNCIATOR AND THE SPD WILL BE CTLED TO THE ALPHA REFERENCE SPD.' AS WE KNOW THE MD80 HAS NO PLT INPUT TO TELL IT WHAT IT WEIGHS; THEREFORE IT COMPUTES IT AND IN STEADY STATE FLT AS THE NOTE ABOVE STATES. THE PHOTOS OF FLTS THAT I HAVE ALONG WITH OTHER EMPIRICAL DATA USING PERFORMANCE CHARTS; AS WELL AS VISUAL REFERENCE TO RWY LENGTH USED AND THE HANDLING CHARACTERISTICS OF THE AIRPLANE ALL SHOW THAT THE FLTS WERE OPERATED EXCEEDING THE PLANNED WT OF THE FLT SEGMENT AND IN SOME CASES WERE ABOVE THE STRUCTURAL LIMITS; RWY LIMITS; AND CLB LIMITS OF THE MD80 SERIES ACFT ABILITY TO SUSTAIN FLT ON A SINGLE ENG. THE CONUNDRUM IS HOW TO FIX THE PROBLEM. WE KNOW HOW MUCH AN EMPTY PLANE WEIGHS AND THE FUEL IN IT. WE KNOW THE WT OF THE CARGO. WE GUESS AT THE WT OF THE PAX AND LUGGAGE. THE 'NOTE' IS WHAT TIES MY WHOLE THESIS TOGETHER.