AN ACR 727 TAXIED WITH MECHS WORKING ON THE ENG.

Narrative

WHILE TAXIING FOR TKOF AT LGA; WE WERE UNABLE TO GET A START VALVE LIGHT ON ENG #3. AFTER TALKING TO MAINT VIA RADIO; WE RETURNED TO THE HANGAR LINE. A MECH PLUGGED INTO INTERPHONE TO DETERMINE OUR PROB. HE THEN UNPLUGGED. THE NEXT COM I HEARD WAS ON THE FO'S OVERHEAD SPEAKER. IT WAS A MECH ADVISING US TO START ENG #3 AND THAT IF IT DIDN'T START; WE WOULD TAXI TO A GATE TO CHANGE THE STARTER. THE START VALVE LIGHT DIDN'T ILLUMINATE. A MECH THEN DROVE FROM BEHIND THE AIRPLANE TO A POINT OFF THE NOSE. WE COULD SEE HE WAS SPEAKING INTO HIS RADIO. ON OUR RADIO; WE WERE BEING TOLD TO START ENG #1 AND #2 AND FIND OURSELVES A GATE. THE TRUCK THEN DROVE OUT OF OUR WAY. AFTER RAMP CTL CLRED US TO GATE X; WE BEGAN TO TAXI. AFTER ABOUT 50 FT; THE TRUCK DROVE IN FRONT OF US; THE MECH JUMPED OUT AND GAVE US AN IMMEDIATE STOP SIGNAL. AFTER WE STOPPED; THE MECH PLUGGED IN AND TOLD US THAT WE HAD TAXIED WITH THE ENG #3 COWL OPEN; A STAND UNDER THE ENG AND 2 MECHS ON THE STAND. NO ONE WAS INJURED. NO PROPERTY WAS DAMAGED. I BELIEVE THIS INCIDENT OCCURRED BECAUSE: 1) COMPLACENCY BTWN COCKPIT AND MECH; 2) CAPT ALLOWING NONSTANDARD COMS (VHF RADIO RATHER THAN INTERPHONE); 3) INTERPRETING CLRNC TO START ENGS #1 AND #2; FIND A GATE; THEN THE TRUCK DRIVING OUT OF OUR WAY AS THE MAINT ALL CLR. A VISUAL HAND SALUTE IS STANDARD. SUPPLEMENTAL INFO FROM ACN 274401: ACR HAS GIVEN THE RESPONSIBILITY OF MARSHALLING ACFT TO THE GATE TO THE BAGGAGE HANDLERS. WHEN AN ACFT RETURNS TO THE GATE AREA; THERE MAY BE AS MANY AS 5 SEPARATE AGENCIES INVOLVED WITH HANDLING THAT ACFT; IE.; GND CTL; RAMP CTL; MAINT; BAGGAGE; CREW. ALL OF WHICH ARE NOT IN COM WITH EACH OTHER NOR ARE THEY FULLY AWARE OF THE FUNCTION OF THE OTHERS INVOLVED.