A B737-800 FO RPTS THAT AFTER CHANGING FROM A ILS 1 TO A VOR/DME RWY 19; A WX RETURN ON FINAL FORCED A GAR WITH A STALL WARNING; SLOW THROTTLE RESPONSE; AND A CREW TASK OVERLOAD. A FOREIGN LANGUAGE CTLR ADDED TO THE CONFUSION.

Narrative

APCH PERSUADED US TO TRY THE VOR/DME RWY 19 APCH ALTHOUGH WE HAD LOADED AND BRIEFED ILS/DME02 RWY 01. WE QUICKLY REBRIEFED AND SET UP THE VOR RWY 19. AFTER STARTING APCH WE SAW WX RADAR RETURN ON APCH COURSE. QUERIED ATC AND THEY SAID PREVIOUS FLT HAD WINDSHEAR ALERT +/- 15 KTS. CAPT ELECTED TO DISCONTINUE APCH. CONFUSION STARTED WHEN I WAS UNABLE TO COMMUNICATE WITH ATC WHICH WAS SPEAKING FOREIGN LANGUAGE TO ANOTHER AIRPLANE WHILE WE INITIATED GAR. WE GOT A MOMENTARY STICK SHAKER IN THE CONFUSION WHICH AFTER DISCUSSION WE THINK MAY HAVE ALSO BEEN RELATED TO TURBULENCE/UNSTEADY AIR (AIRSPEED INDICATOR BOUNCING). I THINK WE HAD 135 KTS; BELOW VREF OF 141 OR SO AND IN THE YELLOW BAND. CAPT QUICKLY RECOVERED AND WE LOST NO ALT. I FELT I SHOULD HAVE BEEN MORE ALERT AND WARNED HIM OF LOW AIRSPEED BUT I DID NOT SEE IT UNTIL THE SHAKER STARTED. WE ALSO THINK SLOW AUTOTHROTTLE RESPONSE WITH AIRPLANE AT GEAR DOWN AND FLAPS 25 THEN 15 MAY HAVE BEEN A FACTOR. AFTER ESTABLISHING COMS WE GOT VECTORED TO THE ILS/DME02 RWY 01 AND LANDED UNEVENTFULLY.