ACR X CFTT BELOW MVA. SYS ERROR.

Narrative

ACR X WAS CONDUCTING A SCHEDULED ACR FLT FROM RICHMOND; VA (RIC) TO WASHINGTON DULLES (IAD). A FRONT WAS PASSING THROUGH THE AREA; CAUSING NUMEROUS RAIN STORMS AND SMALL TSTMS. WE WERE PROCEEDING N FROM RIC TO THE BROOKE VOR; WHICH IS THE S ARR FIX TO IAD. A TSTM DEVELOPED DIRECTLY OVER BROOKE; WHICH CAUSED ALL THE INBOUND ACFT TO DEVIATE FROM THE NORMAL ARR CORRIDOR. THE CTLR ISSUED NUMEROUS VECTORS; MANY OF WHICH WERE REFUSED BY THE ACFT RECEIVING THEM; DUE TO THE MANY SMALL TSTMS IN THE AREA. THE FREQ WAS EXTREMELY BUSY. IT WAS OFTEN LITERALLY IMPOSSIBLE TO GET A WORD IN. ACR X WAS TOLD TO DSND TO 3000 FT MSL AND BEGAN DEVIATING AROUND TSTMS JUST S OF THE BROOKE VOR. WE WERE THEN GIVEN A HDG OF 270 DEGS BY IAD APCH. WE PROCEEDED ON THIS HDG AT A SPD OF 250 KTS FOR ABOUT 10 MINS. IAD APCH WAS STILL EXTREMELY BUSY WITH OTHER ACFT. THE CAPT BEGAN TO EXPRESS CONCERN ABOUT THE HEIGHT OF THE TERRAIN WE WERE APCHING. (WE WERE IMC AT THE TIME.) WE ATTEMPTED TO CONTACT IAD APCH; BUT COULD NOT GET THROUGH THE OTHER TFC ON THE RADIO. BY THIS TIME; I FIXED OUR POS AS 40 MI FROM THE MONTEBELLO VOR ON THE 60 DEG RADIAL. THE MEA ON THE AIRWAY AT THIS POINT IS 6000 FT. WE WERE AT 3000. THE CAPT SLOWED THE ACFT TO 200 KTS; WHILE I AGAIN ATTEMPTED TO CONTACT IAD APCH. THE RADIO ALTIMETER BEGAN TO INDICATE THAT THE TERRAIN WAS RISING; AND WE COULD SEE THE HILLS THROUGH THE FOG AHEAD. I FINALLY GOT THROUGH TO IAD APCH. THEY ADVISED THAT THEY HAD LOST RADAR CONTACT WITH US AND ASKED OUR POS. I GAVE IT AS 40 MI E OF MONTEBELLO. THEY THEN ASKED US TO CONFIRM WE WERE AT 7000 FT. WHEN TOLD THAT NO; WE WERE AT 3000 FT; THEY ISSUED INSTRUCTIONS FOR AN IMMEDIATE R TURN TO 030 DEGS AND A CLB TO 5000 FT. AS WE STARTED THE TURN; WE COULD SEE TERRAIN OUT THE CAPT'S L WINDOW THAT WAS ABOVE THE LEVEL OF THE ACFT. THAT TERRAIN WAS DIRECTLY ON OUR PREVIOUS COURSE. ATC ASKED US TO SWITCH TO ANOTHER TRANSPONDER AND SOON REACQUIRED RADAR CONTACT. A NORMAL APCH AND LNDG WERE THEN MADE AT IAD. SIGNIFICANT FACTORS WERE: 1) THE TOTAL SATURATION OF THE ATC SYS CAUSED BY THE TSTMS. THE CTLR CLRLY 'LOST IT' WHEN THE STORM MOVED OVER HIS INITIAL FIX; THUS DESTROYING HIS PLANS. AS ACFT DEVIATED; THEY WANDERED INTO OTHER SECTORS AND OUR CTLR HAD TO COORDINATE WITH THESE CTLRS. IT WAS BEYOND HIS ABILITY; AND HE COMPLETELY FORGOT ABOUT OUR FLT AS A RESULT. 2) THE TOTAL LACK OF TERRAIN INFO IN OUR COCKPIT. ONCE WE GOT OFF THE AIRWAYS; WE HAD TO DEPEND ON THE ATC SYS FOR TERRAIN CLRNC. WE HAD NO OTHER INFO; EXCEPT TO NOTE THE MEA'S OF AIRWAYS IN OUR APPROX AREA.