Here's a good diagram of how a falling weight trap is triggered.
This is Wings Wendall of the Military Intelligence. Here, we see his plane get battered by the storm until it runs out of hit points (maybe?). On the mountainside, he meets either a planned encounter or a random encounter of 3-5 wolves. We also see him run out of ammo pretty quickly.
There are no details on what the pilots were drugged with and what exactly the drugs did to them. They seem docile...perhaps like they had the effects of a Charm Person spell on them.
(Scans courtesy of Digital Comic Museum)