In the movie Independence Day, there's this scene where a recon plane is approaching the mysterious flying phenomenon that's appeared off the west coast. When the plane breaks through the cloud (or smoke) we see what looks like fire and the plane is obliterated.
The question is: was this some kind of defensive weapon from the alien ship, or was it simply the heat of entry into Earth's atmosphere? The latter would mean that the plane was destroyed unintentionally.
The plane, a USAF AWACS (Airborne Warning and Control System) aircraft was destroyed by the heat of the alien ship's entry into the atmosphere.
The destruction of this plane may be unintentional, but flying at speed into someone's airspace is de facto an act of aggression, especially if you plan to wipe them out.
From the shooting script;
INT. AWAC - SAME The Pilot squints as he tries to see through the clouds.
PILOT : Wait a minute, it may be clearing.
Suddenly the clouds part before us and we're face to face with a WALL OF FLAMES.
INT. AWAC - SAME The speaker phone cracks and distorts.
PILOT : Jesus God! The sky's on fire!
EXT. AWAC AND PHENOMENON - SAME The AWAC attempts to climb sharply as we get our first real look at the atmospheric phenomenon. Majestic and monstrous. The AWAC is not going to be able to make it.
Quickly it is ENGULFED in the flames.
and from the official novelisation
Growing louder, a sonic disturbance, the cracking hiss of static interference, growled over the speakerphone. Then, just as the AWACS broke free of the clouds, the pilot’s voice screamed over the noise, “Jesus God! The sky’s on fire!”
In front of him was a solid wall of flame five miles high and twenty miles long, a majestic and fearsome sight. Roughly disk shaped, it was shedding altitude, dropping down right on top of him. The pilot jerked back on the controls, forcing the plane into a steep climb. But when they came too close to the fireball, the plane suddenly shattered like a lightbulb crashing against an anvil.
When items enter the atmosphere there is normally massive heat created. This bled off into the atmosphere and the poor awac flew into the firewall in front of it. A wake of fire you might say.
It was the alien destroyer's invisible forcefield. We see the alien destroyer's forcefield in use when the U S Marines fighter jets tried to fire missiles at it and they just bounced off the alien destroyer's hull, remember? If you all watch the awacs plane scene again, and listen real closely, you will certainly hear the sound of impact, like something hitting a wall hard! The aliens were cautious because they knew that they were entering an unknown planet with life on it (us!) they knew we had destructive weapons too, and they turned their forcefield on ahead of time. The pilot in the scene says "Pull up!" before they blow up, and the awacs is already in the flames before it blows up.
In the movie the aliens regard our species, perhaps all life on the planet, as naught but an infestation to be scoured from the face of the planet. In that regard, the fire wall could be simply a means of sanitation for their vessels or it could be another form of pesticide. Look at it from their perspective; to them, we're roaches, fit for nothing else but extermination
