Birds have feathery porous wings, and engineers are pondering the reason, with a view to applying it to aircraft wings. One idea is to riddle aircraft wings with tiny holes. Any solid wing has a boundary layer of air. A porous wing can remove this layer by suction, or displace it by blowing. To optimize these effects, says Daedalus, we need a wing that is dense with little holes, but not at 90° to the wing surface. The wing should suck at the front, with each inlet hole pointing forwards to accept air from ahead. It should blow at the rear, with exit holes angled steeply to eject air backwards. The two effects would counterbalance each other, but need not cancel out. The ideal combination would optimize the wing as a lifting device of low drag.

Modern passenger aircraft need to provide cabin air for their passengers. The wings might draw on the plane's air budget, or alternatively might help to supply it; any supply from or drain to the wings must be taken into account. Even so, Daedalus reckons that porous wings must have good physics behind them, or rather beneath them. Nature knows her business.

Daedalus does not intend to power his aircraft from the air extracted ahead and ejected behind by its porous wings, though this should make a useful contribution. His idea is simply to make artificial porous wings as efficient as possible, and with the lowest feasible drag.

So DREADCO engineers are flying blown and sucked wings in a wind tunnel, and comparing the results with those obtained with naturally feathered wings. Both natural and artificially porous wings should have lower drag and higher lift than the standard solid variety. Further, sucking in air at the front while ejecting it at the back should improve the wings both as lifters and thrusters.

One problem will be ice, which at high altitudes grows on even the best wings. But conventional engines are only about 25% efficient, so 75% of their energy is wasted as heat. A distributed cooling system would warm the wings, helping to keep ice away. It could heat the rear-ejected air as well, increasing the thrust of blown wings by a sort of afterburner effect. A plane with cylinder engines could even release its exhaust gases through the rear-facing holes in a blown wing. This would neatly capture energy that would otherwise be lost, and raise the thrust of the wings. Sadly, it would disfigure the usual tasteless painted-on colour scheme.