Not long after riding in his first automobile, Marcel sees his first airplane. Granted that I am always a bit confused about Marcel’s age, not to mention the calendar year of events, the sight of an airplane at this time in the novel seems out of place. Orville Wright was born just a month after Proust and he didn’t make the first flight (despite French claims to the contrary) until 1903, which would make him about 33. The first flights over the French countryside would not likely have occurred before around 1910 (especially one with metal wings), a few years before the war. But let us read the passage.
Suddenly, my horse reared; he had heard a strange sound; it was all I could do to hold him and remain in the saddle; then I raised my tear-filled eyes in the direction from which the sound seemed to come and saw, not two hundred feet above my head, against the sun, between two great wings of flashing metal which were bearing him aloft, a creature whose indistinct face appeared to me to resemble that of a man. I was as deeply moved as an ancient Greek on seeing for the first time a demi-god. I wept–for I had been ready to weep the moment I realised that the sound came from above my head (aeroplanes were still rare in those days), at the thought that what I was going to see for the first time was an aeroplane. Then, just as when in a newspaper one senses that one is coming to a moving passage, the mere sight of the machine was enough to make me burst into tears. Meanwhile, the airman seemed to be uncertain of his course; I felt that there lay open before him–before me, had not habit made me a prisoner–all the routes in space, in life itself; he flew on, let himself glide for a few moments over the sea, then quickly making up his mind, seeming to yield to some attraction that was the reverse of gravity, as though returning to his native element, with a slight adjustment of his golden wings he headed straight up into the sky. (IV,582)
As is well known, Proust modeled the Albertine story after his jealous obsession with his driver, Agostinelli. He escaped Proust’s suffocating attention by fleeing to Monaco, where he took flying lessons under the name Marcel Swann. He died in a crash at sea. I think the recall of Agostinelli’s death, in 1914, is the most likely source of this passage. Especially the abundance of tears at the sight of the plane and the image of it “headed straight up into the sky.”