I came across a story recently about a light aircraft that crash landed, fairly successfully, because it happened to come down on a field of mobile toilet cubicles.
Similarly, stuntmen use nested cardboard boxes to absorb the energy when they fall onto them from a great height in the course of filming.
Today’s invention is a way to make crash landings safer for airliners. The area between runways is usually at least as big as the tarmac itself. This could be equipped with a large number of deformable boxes buried just under the sward.
In the event of an undercarriage or engine failure, a pilot could be directed to belly flop on an expanse of these containers -which would need to have its perimeter delineated by remotely-controlled flares (it might even be worth filling the boxes with water, loaded with fire retardent).
The boxes would be reasonably cheap to make, fill and deploy -whilst still maintaining a low profile.