Airbus A319 C-FZUG 263 needed a high power ground run after being down with a snag for a couple of chilly days. Although it was Craig's snag, he asked me to run the airplane, and he would take the right seat person's duties. Normally, the person in the left seat is fully responsible for all aspects of the run, and he delegates some tasks to the right seat person, usually operating the radios, observing outside the aircraft while at high power, and reading the checklists for whatever maintenance tasks must be performed.
In our case, we had to do a power assurance run, and an acceleration check on each engine. Because the acceleration check involves bringing the engine to take off power, we had to take the airplane to the runway. In some places that would mean towing, but in Ottawa, the engineers taxi the airplane.
At 1 am, we arrived at the airplane. The rampies were busy removing the heater cart, attaching the towbar, and moving the traffic cones at the wingtips. I finished the walk around, went to the cockpit, and turned on the power. Within a few minutes, we were ready to push back. The rampies pushed the airplane so that we faced towards Taxiway Charlie, disconnected the towbar, and drove away. I started the engines, and once the rampies were clear, advanced the throttles to taxi to our run up spot.
The taxi route can be seen, barely, on the old airport diagram above. We started on position 43, were pushed back by the rampies, and then taxied under our own power to the intersection of Runway 32 and Taxiway Charlie. When we came to Taxiway Echo, I nearly blew it, as I was expecting to go to the end of 32, so I went to turn left. Fortunately, Craig was on the ball, and stopped me before I had turned too far. We continued straight to 32, and I made a sweeping turn so that we could check the pavement condition, as well as getting ourselves positioned near the centreline, pointing down the runway.
We stopped, and after double checking the task, I brought both engines to 60% N1. Once stable, I brought the left engine to 67.6%, + or - .5% N1, and we let it run for four minutes. After the time had elapsed, Craig recorded certain parameters - N1, N2, EGT, and fuel flow. I brought the left engine to 60%, then repeated the test on the right engine. Everything was normal on both engines.
Now the fun part. Each engine had to have an acceleration check, to make sure the engines spooled up quickly enough. To be serviceable, the engine had to spool from 30% N1 to Flex - 5% N1 in less than eight seconds. Flex is the throttle setting normally used for take off. It's a calculation based on temperature, and is usually somewhere around 85 or 90% N1. Flex for our run was 86% N1, so the engine had to reach 81% within the time limit.
We had another look at the runway pavement to make sure there wasn't anything to get sucked in, checked to see no airplanes were on approach, as we were blasting across the active runway, 25, and got on the toe brakes hard. The parking brake can't be relied upon to hold the airplane at high power.
I set the non-test engine at 60% N1, brought the test engine to 30% N1, and Craig said, "Go." I immediately moved the throttle to Flex, and I watched N1 spool up, reach the target, and I called "Stop". It was well within limits, only five seconds - the maximum is eight. We did the same for the opposite engine, which also tested fine, brought the engines to idle, and Craig called for taxi clearance back to the stand.
I taxied the airplane to stand 43, where we had to wait only a moment for the rampies to show up and guide us in. We shut down, noted the fuel consumed - 1,200 kgs, about 2,600 pounds, or about 450 gallons, in only a half hour - and secured the cockpit. The rampies hooked up the power cart and heater cart, chocked the airplane, and installed engine covers. We returned to the office, and Craig signed off the snag.
Craig descends from 263 after the ground run.
It was almost two years to the day that I last did a high power run on an A320 (I used to do them once or twice a week while on Phase Check, but that seems like a long time ago now). It came back to me very easily. I have done a couple of idle runs in Ottawa, but those are really only useful for remembering the start and shutdown procedures.
Although I have taxied A320s about a dozen times, this was the first time I'd done so on my own authority, all the previous occasions having been "under supervision".
Really, I don't know how much more fun someone can have at work.
