SMT ACTIVATED THE MSAW WHEN CONDUCTING A STEEP VOR APCH.

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AFTER A RAPID DSCNT; WE WERE CLRED FOR THE VOR 4L APCH AT MWC SEVERAL MI BEFORE PHYLS FAF. CROSSED FAF 40-50' HIGH; WHICH WAS OK BECAUSE WE PLANNED ON A RAPID DSCNT AFTER PASSING FAF TO MINIMUM DSCNT ALT. MADE POSITIVE VISUAL GND CONTACT AFTER SEVERAL HUNDRED FEET OF DSCNT FROM PHYLS (FAF). CONTINUED DSCNT TO MINIMUMS AND TOWARDS RWY 4L MWC. SHORTLY THEREAFTER; RECEIVED A CALL FROM MWC TWR THAT MKE APCH CTL HAD A LOW ALT ALERT WARNING; AND THE TWR GAVE US A NEW ALTIMETER SETTING. WE HAD ESTABLISHED OUR LOCATION VISUALLY BEING FAMILIAR AFTER 35 YRS OF FLYING FROM THE ARPT. BUT; THE CALL WAS STILL VERY DISTRESSING AND DISTRACTING AT A TIME WHEN ALL EFFORTS SHOULD HAVE BEEN DIRECTED TO FLYING THE AIRPLANE AND THE APCH. I BELIEVE THE ALT ALERT SOUNDED BECAUSE THE COMPUTER CALCULATED OUR DSCNT PROFILE TO DIVE US INTO THE GND BEFORE REACHING THE RWY. I TALKED TO SEVERAL INSTRUMENT INSTRS AND THEY COULDN'T TELL ME IF THE APCH CTL COMPUTER WAS PROGRAMMED THAT WAY. FINALLY AN ATP INDICATED HE HEARD OF SEVERAL TIMES THAT IT HAPPENED; AND YES; IT WAS PROGRAMMED INTO THE COMPUTER. I BELIEVE THE LOW ALT ALERT WARNING IS A GREAT SAFETY FACTOR AND IT IS PROPER TO INFORM THE PLT. I THINK; HOWEVER; IF A LOW ALERT IS SOUNDED BY A STEEP PROFILE COMPUTER CALCULATION ON A NONPRECISION APCH; INSTRUMENT INSTRS; PLTS AND STUDENTS SHOULD BE MADE AWARE OF THE FACT SO AS NOT TO BE DISTRACTED TRYING TO FIGURE OUT WHY LOW ALT WAS CALLED WHEN ALL THE GAUGES AND THE APCH SEEM TO BE GOING FINE. THIS COULD BE ACCOMPLISHED SIMPLY THROUGH THE VARIOUS SAFETY NOTIFICATIONS AND AVIATION PUBLICATIONS; BOTH PUBLIC AND PVT. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING: THE RPTR REITERATED THAT HE THOUGHT THE PARAMETERS OF THE MSAW SHOULD BE MORE WIDELY PUBLISHED SO THAT A PLT COULD ANTICIPATE AN ALERT WHEN CONDUCTING A STEEP APCH AND THEN NOT SPEND TOO MUCH TIME WORRYING ABOUT IT. HE ALSO SAID THAT HE WAS DEPENDING ON HIS INTIMATE FAMILIARITY WITH THE TERRAIN ON THIS APCH TO HELP HIM FIND THE ARPT.