I see the Stalingrad airlift as just one more engineering failure by the Germans. A better equipped engineering force and more attuned command would have flown in materials and equipment to construct and maintain the airfields right from the start.
By way of comparison, one reason the US Bastogne airlift was more successful (and the British Arnheim lift failed) was the use of a ground-air radio beacon system coded Rebecca-Eureka. It consisted of portable air droppable transmitters and a homing system in the aircraft. It had sufficent accuracy when operating correctly to ensure drops within a few hundred feet of the target. At Arnheim most of the transmitters for this system were either put out of operation or overrun and captured.