I am very impressed with Northwest's DC9 and DC10 fleet, and would like to add that all of their aircraft are well-maintained. Their DC-10-40 fleet, the oldest types of DC-10s that they operate, flew ontime 88.5 percent of the time in June, an amazing statistic that is a real testament to the maintenance and design of the aircraft as well as the hard work of the people of Northwest Airlines. If your dad gets lucky, he might get a A319 from DTW-JFK and a 747-400 from JFK-AMS, as Northwest often flies these aircraft on those routes. Those are the newest types of airplanes flown by Northwest, and a real treat to fly in. Either way, tell him to have an excellent flight on Northwest and KLM.
Disclaimer...I don't work for NW
Create your own luck.