Air heaters outside the Propulsion Systems Laboratory (PSL)

Air heaters outside the Propulsion Systems Laboratory (PSL) Equipment Building. The three gas-powered combustion air heaters, approximately 40'-0" tall, generated the high temperatures needed for supersonic testing. The heaters ingested ambient air from the compressors inside the Equipment Building. The air flowed through vertical tubes that had been warmed by a natural gas flame as it passed upward through the heater. (7/1/1955)