As many as 11 layers of honeycomb are positioned under the vehicle, but this M1151A1 UAH will compress only four layers during a normal landing. A hard impact at 28.5 feet per second (worst-case scenario) should crush five layers while using the entire nine-inch stroke of the HMMWV’s suspension to absorb the shock.
Lumber and sheets of three-inch-thick paper honeycomb, stacked between the axles, the frame, and the airdrop platform, cushion the impact.
http://blog.caranddriver.com/dropping-democracy-how-the-army-yanks-a-humvee-out-of-a-plane-and-drives-it-away-750-feet-later/
