http://www.joelhayward.org/stalingradairlift.htm
No verbatim records of Hitler's conversation with Jeschonnek have surfaced, but the basic facts are known: Hitler explained that Sixth Army would probably be totally cut off within days, that he had organized a new army group under von Manstein, and that it would launch a relief effort as soon as possible. He hoped not only to free Sixth Army within a short time, but also to regain lost territory and rebuild a strong defensive line. Apparently understanding Sixth Army's encirclement to be temporary, Jeschonnek assured Hitler that if both transport planes and bombers were used, and if adequate airfields inside and outside the pocket could be maintained, the Luftwaffe could airlift sufficient supplies to the army.
Jeschonnek's spontaneous and ill--considered assurance that the air force could sustain Sixth Army at Stalingrad pleased Hitler. He could hardly allow the army to abandon that city after he had proclaimed to the entire German nation in September that “you can be certain no one will get us away from there!”
Von Richthofen considered it sheer madness for Paulus and his staff to plan an all--around defense at Stalingrad and pin their hopes on the Luftwaffe to sustain their army. The air force simply lacked the ability to keep it supplied, he frantically warned everyone who would listen. “Sixth Army believes that it will be supplied by the air fleet in its hedgehog positions,” he complained in his diary on the 21st. “I make every effort to convince it that this cannot be accomplished, because the necessary transport resources are not available.” During “dreadfully many telephone calls . . . until late in the night,” he emphatically insisted to almost every relevant air force and army leader—including Göring in Berlin, Zeitzler in East Prussia, Jeschonnek at Berchtesgaden, and von Weichs at Army Group B headquarters—that he lacked the means to supply Paulus's army. It should immediately attempt to break out.
The firmness of Hitler's conviction that the “fortress” should stand fast and that the Luftwaffe could keep it adequately supplied had grown considerably in the two days since Jeschonnek had first mentioned it. One of the main reasons for his increased conviction was the almost unanimous support for the decision expressed by those around him. At Berchtesgaden, and during his long train journey to East Prussia on the 23d, Hitler had no contact—personal or telegraphic—with the army and air force commanders at the front. During that critical decision--making period, he did not speak to von Richthofen, Fiebig, or Pickert, whose air forces would have to carry out the massive supply operation and who were now frantically warning almost everyone else that they lacked the means to sustain Sixth Army. Nor did he communicate with von Weichs, who shared their view and advocated an immediate breakout. Hitler learned of their views from Zeitzler, who had finally “come around” and now defended their assessment. Yet, because their warnings were not delivered personally, but only passed on by the army's “overanxious” chief of staff, they carried little weight. Hitler merely accused Zeitzler of being too pessimistic and advised him to stop paying heed to “defeatist” commanders who couldn't see the forest for the trees.
Aside from Zeitzler's, the only dissenting voice Hitler heard during his last two days in Berchtesgaden and his long journey north to East Prussia belonged to Jeschonnek, who had abandoned his earlier position and now meekly suggested that Sixth Army should break out. He regretted his earlier assurances to Hitler. Almost as soon as the words were out of his mouth, he wished he could swallow them again. After having his staff check his figures and after talking with von Richthofen several times by telephone, he quickly realized that nothing close to adequate logistical support of Sixth Army by air would be possible, even with consistently favorable weather and taking no account of VVS action. He and von Richthofen were close friends, but the latter clearly dominated their relationship and, when they disagreed on matters, usually managed to win Jeschonnek over. This was clearly one such case. However, although Jeschonnek notified Hitler that he might have been too hasty when he made his earlier assessment, his retraction carried no weight. Not only did Keitel and Jodl believe Sixth Army should stay, Hitler retorted, but Jeschonnek's own superior, Reichsmarschall Göring, had now given his personal assurance that the air force could fully meet the army's supply needs.
And:
..on 11 February 1943, almost two weeks after Paulus surrendered and his surviving troops staggered into Soviet captivity. Hitler admitted to von Richthofen that Göring was not entirely to blame for the failed airlift; he had himself promised Sixth Army that it would be supplied by air, “without the Reichsmarschall's knowledge.”