G+H Noise Control received an order for the acoustic lining of three test stand rooms as well as for the delivery and installation of the associated highly sound-absorbing test stand doors. The realization of the air intake flap was a technical challenge. The flap enables the vehicle to be supplied with cooling air during normal operation of the test bench. In acoustic measurement mode, the flap is lowered into the ground within 10 seconds. In order to avoid possible crushing at the edges of the flap, it was driven by a force-monitored electric cylinder. This and the associated control stops the flap as soon as an obstacle prevents it from closing.