A300 CREW HAD AN EGPWS 'TERRAIN; TERRAIN' WARNING ON THE VOR DME RWY 11 APCH INTO MDST.

Narrative

FLT WAS IN A MEDICAL EMER DUE TO PAX SUFFERING POSSIBLE HEART ATTACK. MEDICAL SIT WAS NOT CONTRIBUTORY; ACFT WAS ALREADY SLOWED AND ON THE ESTABLISHED APCH. FLT WAS CLRED TO EXECUTE THE VOR/DME RWY 11 AT STI. DUE TO SEVERAL CELLS OF MODERATE INTENSITY; THE CHOICE TO FLY THE VOR 11 APCH MINIMIZED WX PENETRATION AND THUS REQUESTED TO SANTO DOMINGO CTL AND GRANTED. ACFT WAS DSNDING FROM 5200 FT FROM OVER THE SGO VOR ON THE 270 DEG RADIAL IN NAV MODE; FO HAD EGPWS DISPLAYED; CAPT WAS IN WX RADAR. ACFT WAS ESTABLISHED SOLIDLY ON THE 270 DEG RADIAL OUTBOUND; HOWEVER; ACFT DID NOT INITIATE TURN PRIOR TO REACHING TOE 10 DME OFF SGO TO BEGIN TURN INBOUND ACFT WAS OUT OF 3600 FT TO 2600 FT AND IN A NORTHEASTERLY TURN TO INTERCEPT THE 110 DEG RADIAL INBOUND; RADIAL WAS ALIVE AT 11.1 DME AND ACFT WAS IN HDG SELECT TO KEEP IN TIGHTER AS A RESULT OF NAV MODES POOR COMPLIANCE. AIRSPD WAS 180 KIAS; FLAPS 20 DEGS WHEN 'TERRAIN; TERRAIN' ANNUNCIATED; AND ACFT WAS IMC. CAPT IMMEDIATELY INITIATED AN 'ESCAPE' MANEUVER AND CLBED TO 5200 FT TO THE SGO VOR. SECOND APCH FLOWN ON THE 12 DME ARC TO THE N WITH MINOR ALTERATIONS FOR WX SUCCESSFULLY TO LNDG. FOR OVER 1 YR I HAVE REQUESTED THAT A 10-1 MAP PAGE BE MADE FOR THE STI ARPT. FLT OPS TECHNICIAN STATED AN ENLARGED SANTO DOMINGO 10-1 WAS IN THE WORKS AND THIS WOULD COVER THE STI AREA. NOTHING. THE PRECIPITOUS TERRAIN AROUND THIS FACILITY IS NUMEROUS; YET WE CONTINUE TO FLY WITHOUT THIS SITUATIONAL AID ENHANCER. MY RECOLLECTION LEADS ME TO BELIEVE EITHER THIS APCH WAS NOT ADEQUATELY CHARTED BEFORE CERTIFICATE OR THE NAV DATABASE FOR THE A300 IS IN ERROR FOR THE VOR 11 TO STI SINCE IT DOES NOT LEAD THE TURN AS IT DOES ON SIMILAR APCHS TO OTHER AERODROMES. PERHAPS A RIDGE EXTENDING OUT OF THE SURROUNDING TERRAIN IS HIGHER THAN DEPICTED (THUS THE NEED FOR AN ACCURATE 10-1) OR PERHAPS THE EGPWS DATA HAS AN INADEQUACY PROMPTING A FALSE WARNING. WHICHEVER OR IF ALL THE ABOVE; THIS APCH SHOULD ONLY BE PERMITTED VMC TILL FURTHER CLARIFICATION CAN BE DETERMINED AND TO ENSURE SAFETY AND THE PRESERVATION OF LIFE AND LIMB.