Narrative:

The APU air was MEL'ed inoperative; thus requiring an air start at each departure airport. All 3 airports required me to start the #2 engine first; pushing the aircraft off the gate prior to starting #1 engine. Our carrier does not have a procedure to start #2 engine first at the gate; much less; push with that engine being the only engine running during pushback. Using the procedures currently in effect as pertains to the nosewheel steering switch and push procedures; when the aircraft has only #2 engine running during push; there is no down hydraulic pressure on the gear! This is a potentially dangerous situation! As C/O; I am monitoring aircraft system prior to; during; and post-pushback. First officer; maintenance; and myself discussed situation -- made do with the procedures we had on hand; and continued the operation. Evidently; ground crews are used to starting #2 engine first (boeing versus ab??). In most instances; I've been told they do not have the ramp space to position the start-cart on the starboard side of the aircraft. Develop a procedure for starting #2 engine prior to starting #1 engine using air start procedures. Green hydraulic pressure must be available to down-side of gear prior to aircraft movement! Or -- and the easiest -- position start cart on starboard side of aircraft or increase start hose length to aircraft to enable starting #1 engine at the gate; thus providing the required green hydraulic pressure. Having green hydraulic down-pressure on gear prior to an unpinned gear being pushed is paramount.

Google
 

Original NASA ASRS Text

Title: A320 CAPT REPORTS PUSH BACK WITH NUMBER 2 ENGINE ONLY RUNNING AND ANTI SKID AND NOSE WHEEL STEERING SWITCH OFF.

Narrative: THE APU AIR WAS MEL'ED INOP; THUS REQUIRING AN AIR START AT EACH DEP ARPT. ALL 3 ARPTS REQUIRED ME TO START THE #2 ENG FIRST; PUSHING THE ACFT OFF THE GATE PRIOR TO STARTING #1 ENG. OUR CARRIER DOES NOT HAVE A PROC TO START #2 ENG FIRST AT THE GATE; MUCH LESS; PUSH WITH THAT ENG BEING THE ONLY ENG RUNNING DURING PUSHBACK. USING THE PROCS CURRENTLY IN EFFECT AS PERTAINS TO THE NOSEWHEEL STEERING SWITCH AND PUSH PROCS; WHEN THE ACFT HAS ONLY #2 ENG RUNNING DURING PUSH; THERE IS NO DOWN HYD PRESSURE ON THE GEAR! THIS IS A POTENTIALLY DANGEROUS SIT! AS C/O; I AM MONITORING ACFT SYS PRIOR TO; DURING; AND POST-PUSHBACK. FO; MAINT; AND MYSELF DISCUSSED SITUATION -- MADE DO WITH THE PROCS WE HAD ON HAND; AND CONTINUED THE OP. EVIDENTLY; GND CREWS ARE USED TO STARTING #2 ENG FIRST (BOEING VERSUS AB??). IN MOST INSTANCES; I'VE BEEN TOLD THEY DO NOT HAVE THE RAMP SPACE TO POS THE START-CART ON THE STARBOARD SIDE OF THE ACFT. DEVELOP A PROC FOR STARTING #2 ENG PRIOR TO STARTING #1 ENG USING AIR START PROCS. GREEN HYD PRESSURE MUST BE AVAILABLE TO DOWN-SIDE OF GEAR PRIOR TO ACFT MOVEMENT! OR -- AND THE EASIEST -- POS START CART ON STARBOARD SIDE OF ACFT OR INCREASE START HOSE LENGTH TO ACFT TO ENABLE STARTING #1 ENG AT THE GATE; THUS PROVIDING THE REQUIRED GREEN HYD PRESSURE. HAVING GREEN HYD DOWN-PRESSURE ON GEAR PRIOR TO AN UNPINNED GEAR BEING PUSHED IS PARAMOUNT.

Data retrieved from NASA's ASRS site as of May 2009 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.