How others will see it. Classic action movie fans will love it, of course, and will especially enjoy seeing Rathbone and Niven in heroic roles that play against their later career stereotypes. In tone, of course, The Dawn Patrol is simply an earlier version of Twelve O'Clock High, although the former is clearly better, since there is less hand-wringing and exaggerated drama. Not that The Dawn Patrol doesn't exhibit this, it does, but in lesser degrees, perhaps because Flynn is much less stiff in the role than Gregory Peck.
How I felt about it. In The Dawn Patrol, flying a Royal mission over enemy lines is like a round of Russian Roulette. There is a one in six (or so) chance you'll get your head blown off. Yet every day, fresh young pilots (aptly called replacements) appear to take your place. Where the planes are coming from, heaven knows.
So, why do people do it? For God and King? They drink and carouse all night, then fly a deadly mission in the morning. They are under incredible stress, of course, for fear (and avoidance of fear) of their own lives as well as their comrades.
Stress creates intense arguments among the Royal air base leaders. The roles of base commander and squad leader change between Rathbone, Flynn, and Niven, but no matter who is in which shoes, they soon learn to dislike each other, casting blame for the deaths of their buddies. Of course, real blame must be assigned to the politicians that control the military complex, who view war as a map or board game, rather than as a slaughterhouse.
The experiences pilots instead view the war as a contest between the rival British and German teams. Life and death is at stake, but honor takes precedence, and it is better to die a hero than to go out a coward. Those shot down but cheat death, such as the German prisoner and his would-be victim Niven, are the biggest heroes of all, more so than the bomber who obliteraates his target.
The rookie pilots have interchangable faces and names, and are mere placeholders. They are eager and willing, and are in awe of the situation, built up by propaganda and patriotism. They only wish to take part, but their minor role is brief, since they often die on their first mission. The survivors are those who learn to distinguish between duty and adventure.
The Dawn Patrol is better than most war films. Its excesses and pathos does not overwhelm its message; that duty must be fulfilled, however arduous and exasperating the task.