Chapter six of William Golding's Lord of the Flies is titled "Beast from the Air," and this the chapter in which a parachutist arrives on the island. The boys have all been experiencing nightmares about beasts, and even the older boys are partially convinced there might be some kind of beast on the island. In this symbolic novel, a microcosm of the war that is raging in the "adult" world outside the island, the parachutist is certainly representative of something, and Golding affirms that in the narrative.
But a sign came down from the world of grown-ups, though at the time there was no child awake to read it. There was a sudden bright explosion and corkscrew trail across the sky; then darkness again and stars. There was a speck above the island, a ﬁgure dropping swiftly beneath a parachute, a ﬁgure that hung with dangling limbs.
The parachutist is obviously someone who ejected from a failing plane during a skirmish near the island. It is a breezy night, and the parachutist eventually lands on top of the mountain. It is evident that the man is dead, but he seems to have life because of the wind.
When the breeze blew, the lines would strain taut and some accident of this pull lifted the head and chest upright so that the ﬁgure seemed to peer across the brow of the mountain. Then, each time the wind dropped, the lines would slacken and the ﬁgure bow forward again, sinking its head between its knees. So as the stars moved across the sky, the ﬁgure sat on the mountain-top and bowed and sank and bowed again.
In the morning, Samneric see the odd sight and immediately run for camp as their imaginations get the best of them, assuring the others that they saw a horrible beast with teeth and claws chasing after them. They have identified this figure as the beast, but they do not recognize that it is them--a human.
Simon eventually comes to the accurate realization that the beast is them, and he cuts the lines, releasing the parachutist to finally settle at peace in the ocean.
Clearly the death of this soldier is a foreshadowing of one or more deaths to come. The parachutist is also evidence both that the boys (and the unchecked propensity for evil) are the only beasts on the island and that war on a larger scale is happening away from the island.
When the pilot dies, i think it represents the fact that adults are disappearing in the boys' savage world.