Detroit Metropolitan Wayne County Airport (DTW)
Click the map to go to Google Maps satellite view of this airport
There are decent opportunities to view and photograph planes at the Detroit airport even without an “official” Observation Area.
If you go to the McNamara Terminal parking garage you will find excellent views of runway 3L/21R and the taxiways that go around the midfield terminal complex. Most of the widebody and international jets will use the runways on the other side (4L, 4R) because it is closer to the International Terminal. For aircraft leaving the McNamara Terminal (shown in black on the map) it can be a long way to taxi to the end of 21R, so Delta’s international flights will also use the runways on the west side. But you’ll see nearly every other type of aircraft from the parking garage.
If you go along the I-94 Service Rd. (also known as the Goddard Rd. Extension) as shown on the map you can stop near the end of runways 22L & 22R and get a great view of the widebody aircraft landing. I would not stay for an extended time though, to avoid being hassled by police. I did not have any problems with security in the McNamara garage.
Detroit is a major hub for Delta and also sees traffic from Europe as well as all the other airlines from America so there is definitely a wide variety and continuous flow of traffic here. If you want to photograph from the garage, the best time would be starting three hours before sunset because you face east. From the I-94 Service Rd, you could photograph in morning or evening because you can park on either side of the centerline and face either east or west. Most of the international flights arrive from Asia in the early afternoon and from Europe in the late afternoon.