C-17. The funny thing is that the whole thing started about 300 miles east of Gander (we originally departed from there also), when a copilot asked me if I'd go through his training "coloring book." He needed to review 3 engine drift down procedures, and no kidding about 1 minute into our discussion we started getting compressor stalls on #4. About 5 minutes later, we were in the middle of a 3 engine drift down and emergency turn around on the NATs. We couldn't get back into Gander due to freezing rain, and everything seemed to be OK so we headed back to Bangor where there was enroute MX available and the WX was forecast to be good.

We had plenty of time to pre-brief everything ranging from dumping fuel (once we descended low enough) to flying the approach. Everything was fine until about 10 minutes from top of descent. We started getting a lot of strange issues on the #4 hydraulic system and #4 electrical generator. Then we got a few intermittent pitch trim issues but didn't think much of it because it's connected to #4 hydraulic. Passing our max fuel dump altitude, we started running the checklist and NOTHING happened. It was strange... every possible fuel dump "fail" light or "low press" light was illuminated. About that time, the #4 generator failed and we had some intermittent #4 hydraulic problems... still nothing too incredibly bad, because the #4 HYD was only being run off a backup electrical pump and we lost the #4 generator... so far everything corresponded to the bad engine. As we got closer to the airfield, we got the ATIS and learned that BGR was in the midst of an unexpected snow storm and vis was about 1/4 mile in blowing snow. So we elected to hold and try to figure out *** was going on. About 15 miles from the FAF, we got the Lower Rudder Fail, Right Aileron Fail, and XXXX Spoiler Fail messages. Now I'm starting to think that something much worse could be going on - like a wing fire or something crazy. That's when I figured that we were done troubleshooting and it was time to just fly the approach. It was an ugly approach... full stick and the jet just barely starts to turn, then I try to roll out and I overshoot... 2 dots left at about 2,000 feet.... 1.5 dots right side at about 1,500 feet... 1 dot left at about 1,000 feet, and slowly working back towards centerline and learning how to play out the jet that just doesn't want to turn. Eventually got it to about 1/2 dot or so. Thank God we started seeing the ground at about 500 feet and picked up the runway lights at just under a mile away.

Karma is a *****! That's what I get for talking about 3 engine drift down on the NATS while actually crossing the NATS. I'm just glad that we weren't discussing ditching!