I see a lot of the smaller commercial airplanes around every day. I love them but let’s face it, seeing the same planes all the time can get a little boring. So it’s always fun when something new and different stops by. On a recent Tuesday morning I heard that a Boeing 767 had diverted with mechanical trouble the night before. The 767 might be a common sight at some airports but it is a rarity for us, so I made a point of searching it out.
I finally tracked it down at a gate on the east side of the airport. There were no obvious signs of trouble, but I’d heard that there were oil pressure issues and that it might require an engine change. I shrugged that off. The airline doesn’t have maintenance facilities here and the available hangars would be much too small. No, I figured they’d send a mechanic to patch it up enough so it could be flown to a base. No one would try swapping out engines on the ramp, Right?
Wrong! When I checked on the plane the next day I found that it had been moved from the gate to a parking spot on the ramp. Sitting nearby, covered in protective wrap, was the unmistakable shape of an engine. What the… Oh my goodness! They really ARE going to swap engines on the ramp!
I have witnessed my fair share of gate-side airplane repairs. It isn’t unusual to find mechanics tinkering with engines or landing gear. I’ve even witnessed a nose cone swap. But changing engines on a B767 is a different story. You can’t just dispatch one guy with a wrench to take care of it. I’ve been fortunate enough to visit two of American Airline’s maintenance hangars, so I’ve seen the equipment that is usually needed to do this kind of job. How on earth were they going to pull this off outside?
I decided right then and there that I was going to stalk the heck out of this airplane. For the next several days I spent every spare moment watching as the work progressed. I got to the office early so I could check in before heading to my desk. I spent my lunch break outside. I stayed late after work. I was kind-of obsessed. OK, actually I was TOTALLY obsessed. How often does an engine change happen out in the open for the whole world to see?
The swap began when a small army of mechanics showed up with ladders and a big blue truck with a crane on it. I could see they had opened up all the panels that surround the engine and it looked like they were busy disconnecting things. They used the crane to lift the cowling off the front of the engine and place it on the ground. When I headed home Wednesday night, they were still hard at work.
When I returned Thursday morning I discovered that they had managed to remove the old engine before calling it quits the previous day. The plane looked pretty strange sitting there with one engine missing! It did not stay that way for long. By mid afternoon the new engine had been hung on the wing and when I left work Thursday night they were still busily reconnecting the hydraulic, fuel and electrical lines.
I wondered how long this engine swap would have taken and whether it would have been handled differently if they could have done it in a hangar. My friend Mike from the Flying and Life podcast put me in touch with AJ, a mechanic for a major legacy carrier in the US. AJ has done plenty of engine changes both at the maintenance facility and on the road. He walked me through the basics of the process and explained that a typical engine swap on a 767 takes around 10-11 hours.
AJ told me that weather presents the biggest challenge when working on the ramp. He has completed engine changes in the rain (which doesn’t sound like fun AT ALL). He also said that they will sometime construct a temporary shelter for protection while they’re working. If the weather is really bad they’ll stop work altogether. Equipment can present another challenge. If something breaks then a replacement will have to be brought in which can take time and cause delays.
In this particular case the mechanics were blessed with lovely weather and (apparently) no equipment issues. Friday morning I watched as they closed up all the access panels and began moving the ladders and cranes away from the plane. I had spent so much time watching the work that I felt really invested in the outcome. I wanted to see the engines start up! I NEEDED to see the plane take to the sky!
I spent the rest of the afternoon sweating it out as my desk. A departure time was scheduled and then pushed back and then pushed back again. That was the longest afternoon EVER. I dashed upstairs as soon as I finished work, just in time to witness the engine start. Hooray!
They let the new engine run for a bit and then they fired up the other one. Then the plane eased forward and began to taxi out to the runway. Now came the moment of truth: how would the new engine perform on departure? The plane rolled down the runway, lifted up into the sky, executed a graceful turn to the left and disappeared into the distance. Wow! From broken to restored again in less than three days – what an epic journey! Major kudos to the mechanics involved – and to ALL the mechanics everywhere for all they do to keep planes flying safely.
Author’s note: A very big thank you to AJ and to all my mechanic friends on twitter for answering my many questions! Also, check out season 3, episode 14 of The Traffic Pattern Podcast where Derek Vento and I talk all things aviation!