A mechanically steered hemispherical lens antenna was investigated using the commercially available MOM software FEKOTM to meet a requirement for a low weight and low cost mm-wave transmit antenna for installation onboard a large passenger aircraft. Hemispherical homogeneous lenses of relative permittivity 2.5 and 4 wavelength radius were found to meet the 26.5 dBic gain specification across 75deg elevation scan range. Distorting the circular reflecting plate under the hemispherical lens to an elliptical shape was found to increase the elevation scan range to 105deg, satisfying the scan requirement. Similar results were obtained with a relative permittivity 1.7 lens, when fed by a near field focused horn antenna. The advantage of the latter design is 40% reduction in mass of the lens.