by Dick H
I was not on the trip, so my information is second hand. Some relay failed and the 573 overheated. I believe they were able to get it running for the trip back down. At any rate, the snow and leaves may have been a problem for the 4266 alone and they may not have wanted to come down with just the 4266 running, if they couldn't get the 573 running. Better safe than sorry....So they sent the FP9......
Dick
Dick