A319 CREW HAD ENG MALFUNCTION ON DEP AT LGA.

Narrative

UPON DEPARTING RWY 4 AT LGA; ENG #1 BEGAN TO SURGE AT ABOUT 500 FT AGL. COMPLIED WITH ECAM AND APPROPRIATE PROCS. DIVERTED TO JFK FOR LNDG. EMER DECLARED; EQUIP STANDING BY; UNEVENTFUL LNDG. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: BOTH CREW MEMBERS WERE LINE CHK AIRMEN AND INSTRUCTORS AT THEIR ACR TRAINING CTR. THE CAPT SAID HIS FIRST THOUGHT WAS THIS CAN'T BE HAPPENING; IT ONLY HAPPENS IN THE SIMULATOR. THE ACFT HAD CFM-56 ENGS. THE ENG WAS SURGING BTWN IDLE AND CLB THRUST. THE CREW PULLED THE ENG TO IDLE AND IT OPERATED SURGE FREE SO THEY LET IT REMAIN AT IDLE. SINCE THE ACFT WAS BELOW 1500 FT; ALL ECAM WARNINGS WERE INHIBITED. THE CREW HAD ANOTHER ACR PLT DEADHEADING IN THE COCKPIT. SINCE THIS CREW WAS UNFAMILIAR WITH JFK ARPT; AND THE DEADHEADING PLT WAS INTIMATELY FAMILIAR WITH JFK; HE BECAME AN ACTIVE CREW MEMBER BY PROVIDING THE DESIRED RWY AND GOT ALL THE APCH PAGES FROM HIS MANUAL FOR THE CREW. THE CAPT STATED HE WAS AN IMMENSE HELP. AFTER LNDG THE CREW HAD 'FUEL SENSOR UNIT #1 AND FUEL CTL #1' ECAM WARNINGS. MAINT SAID THERE WAS A 'HYDRO MECHANICAL UNIT #1' FAULT.