Like a smile with missing teeth, the jet’s wings have a gappy quality. Their flaps are gone, exposing a tangle of multi-coloured pipes, tubes and wires. It’s not a dignified look for a plane used to ferrying the wealthy and famous around the globe, yet it will have been worth it if new shape-shifting wings can make aviation safer, quieter and more efficient.

The flaps on conventional aircraft wings provide lift, allow safe slow flight and shorten takeoff and landing distances. Unfortunately, they also open up gaps in the wing’s edge, creating turbulent, messy, airflow, which generates noise and makes flight less efficient.

This explains the major surgery underway on a Gulfstream III executive jet in one of the hangars at the newly renamed Nasa Armstrong Flight Research Center (formerly Dryden), about an hour north of Los Angeles, California. In place of the jet’s old flaps, Nasa engineers are fitting a new bendable wing control surface known as an Adaptive Compliant Trailing Edge (ACTE).

The technology’s key advantage is that it eliminates the gaps in wing edges seen in traditional hinged flaps, replacing them with a gently contoured transition. This improves efficiency compared to traditional flaps which are designed for one particular set of flying conditions, according to Craig Stephens, lead engineer for ACTE at Nasa Armstrong. “It’s a continuous flap so you don’t have that break in the wing,” he says. “The structure having that ability allows you to have the aerodynamic efficiency over a wider range of the flight.”

ACTE has been developed by a company named Flexsys. Stephens is reluctant to reveal too many details about how exactly the flexible structure is built and actuated, but the company’s website hints that composite materials, combined with aluminium or titanium, are involved. The system is designed to have jointless mechanisms, using the elasticity of the materials for shape morphing, and with built-in actuators and sensors.