Hay Road offers an arrival spot for RWY21L that gives a more side-on perspective. Hay Road runs through the centerline for RWY21L so there are angles available for both the morning and the afternoon.
There's a few pullouts along Hay Road you can stop at. If going from the south side of the field to the north side of the field, expect it to take around 20 minutes to drive. Note that the speed limit on Hay Road is quite high, so be careful when getting out of your vehicle to get pictures. I wouldn't stay at these pullouts for too long simply because it isn't exactly safe to be hanging out on the side of the road where the speed limit is 45+.
For mornings, there is a pullout just east of the entrance of the dump. The pullout is on the shoulder of the eastbound side of the road. If coming from the east (heading west), you can make a U-turn at Burke Lane or the entrance to the dump.
For the afternoons, there is a pullout along the westbound side of the road. While there are driveways you can pull into, this is private property and it is not recommended that you pull into there. As an alternative, you can also park along Dally Road which runs perpendicular to Hay Road. The pullout just gets you closer to runway centerline.
You are quite far from the planes from this spot. Another thing that compounds this is that the planes are generally pretty high here. Luckily, Travis usually gets large planes. A 100-400mm lens should work here, but again the further the reach, the more of a head on angle you can get
1:30PM spring, 900mm
1:30PM spring, 450mm