align-view ("avw")
See this command in the command table.
To access this command:
- 
                                                
View ribbon | View | Align
 - 
                                                
Enter "align-view" into the Command Line.
 - 
                                                
Use the quick key combination "avw".
 
Command Overview
Temporarily align the view direction so it is perpendicular to the active section plane.
Command steps:
- Activate a 3D window.
 - If multiple windows are shown (due to horizontal or vertical splitting) highlight one by left-clicking it.
 - Run align-view.
The view direction of the target 3D window is adjusted to be orthogonal to the current section plane.