The idea of the Firebird originated with Harley Earl who also designed its fibreglass, reinforced plastic body. The car's Whirlfire Turbo-Power engine and the chassis were developed under the direction of GM Vice President Charles McCuen, general manager of GM Research Laboratories Division. The aircraft motif is evident in the car's "needle" nose, delta wings swept back over the rear of the body, a vertical tail fin and a plastic bubble over the driver's cockpit. Mechanically, the gas turbine of the Firebird is the reverse of conventional automobiles. In the nose, ahead of the driver is a 35-gallon glass fibre-plastic fuel tank. Behind the driver is an integrated power "package" with an engine consisting of two mechanically independent parts - the gasifier section and the power section.