Interior view of the slotted throat test section installed in the 8-Foot High Speed Tunnel (HST) in 1950. The slotted region is about 160 inches in length. In this photograph, the sting-type model support is seen straight on. In a NASA report, the test section is described as follows: The test section of the Langley 8-foot transonic tunnel is dodecagonal in cross section and has a cross-sectional area of about 43 square feet. Longitudinal slots are located between each of the 12 wall panels to allow continuous operation through the transonic speed range. The slots contain about 11 percent of the total periphery of the test section. Six of the twelve panels have windows in them to allow for schlieren observations. The entire test section is enclosed in a hemispherical shaped chamber. John Becker noted that the tunnel s final achievement was the development and use in routine operations of the first transonic slotted throat. The investigations of wing-body shapes in this tunnel led t