Narrative:

Flight departed bna over 3 hours behind schedule due to maintenance/equipment delay. I was evaluating a first officer due to a previous irregularity that the pilot had been involved. There was also an instructor/check airman on the jump seat fulfilling an annual observation flight requirement. A flight attendant and 28 not very happy passenger were also on board. At a cruise of 15000 ft MSL we were cleared to cross 30 NM west of tys VORTAC at 11000 ft. A strong tailwind resulted in a descent ground speed of greater than 385 KTS. Progressive altitudes were given -- 11, 7, 4, and finally 2500 ft until FAF. ATC issued vectors for spacing, descent, and intercepting the localizer, the required rate of descent was 1850-2000 FPM to attain the 2400 ft at buzby OM (FAF). As the aircraft passed 2500 ft MSL, the GPWS issued 'terrain' and 'pull up' alerts. I immediately disconnected the autoplt and initiated a level off and the climb from 2300 ft to 2400 ft MSL, continuing the ILS 23 right approach and landing within normal profile. I had distracted my attention from monitoring the autoplt input/output to make final navigation tuning and set-up. The first officer had responded to ATC clearance to 2500 ft just prior to reaching 4000 ft MSL. He set 5500 ft on the altitude alert (reason unknown) so the autoplt did not initiate level off as expected. Due to the high rate of descent, the GPWS gave warning in time to prevent impact with obstacle/terrain. On behalf of my crew and the 28 unknowing passenger, I would like to thank all of those responsible for GPWS engineering and legal requirements for preventing this accident.

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Original NASA ASRS Text

Title: ACR LTT HAS GPWS ACTIVATE ON DSCNT TO FAF.

Narrative: FLT DEPARTED BNA OVER 3 HRS BEHIND SCHEDULE DUE TO MAINT/EQUIP DELAY. I WAS EVALUATING A FO DUE TO A PREVIOUS IRREGULARITY THAT THE PLT HAD BEEN INVOLVED. THERE WAS ALSO AN INSTRUCTOR/CHK AIRMAN ON THE JUMP SEAT FULFILLING AN ANNUAL OBSERVATION FLT REQUIREMENT. A FLT ATTENDANT AND 28 NOT VERY HAPPY PAX WERE ALSO ON BOARD. AT A CRUISE OF 15000 FT MSL WE WERE CLRED TO CROSS 30 NM W OF TYS VORTAC AT 11000 FT. A STRONG TAILWIND RESULTED IN A DSCNT GND SPD OF GREATER THAN 385 KTS. PROGRESSIVE ALTS WERE GIVEN -- 11, 7, 4, AND FINALLY 2500 FT UNTIL FAF. ATC ISSUED VECTORS FOR SPACING, DSCNT, AND INTERCEPTING THE LOC, THE REQUIRED RATE OF DSCNT WAS 1850-2000 FPM TO ATTAIN THE 2400 FT AT BUZBY OM (FAF). AS THE ACFT PASSED 2500 FT MSL, THE GPWS ISSUED 'TERRAIN' AND 'PULL UP' ALERTS. I IMMEDIATELY DISCONNECTED THE AUTOPLT AND INITIATED A LEVEL OFF AND THE CLB FROM 2300 FT TO 2400 FT MSL, CONTINUING THE ILS 23 R APCH AND LNDG WITHIN NORMAL PROFILE. I HAD DISTRACTED MY ATTN FROM MONITORING THE AUTOPLT INPUT/OUTPUT TO MAKE FINAL NAV TUNING AND SET-UP. THE FO HAD RESPONDED TO ATC CLRNC TO 2500 FT JUST PRIOR TO REACHING 4000 FT MSL. HE SET 5500 FT ON THE ALT ALERT (REASON UNKNOWN) SO THE AUTOPLT DID NOT INITIATE LEVEL OFF AS EXPECTED. DUE TO THE HIGH RATE OF DSCNT, THE GPWS GAVE WARNING IN TIME TO PREVENT IMPACT WITH OBSTACLE/TERRAIN. ON BEHALF OF MY CREW AND THE 28 UNKNOWING PAX, I WOULD LIKE TO THANK ALL OF THOSE RESPONSIBLE FOR GPWS ENGINEERING AND LEGAL REQUIREMENTS FOR PREVENTING THIS ACCIDENT.

Data retrieved from NASA's ASRS site as of July 2007 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.