(FWIW, the B-24 was the only airplane of WWII that was run LOP in cruise. It seemed to work quite well as it carried the highest bomb load the greatest distance.)
Um Walter maybe not? Well not the only one to run LOP.
ttp://www.475thfghf.org/Lindbergh.htm
The second and critical passage made by the group concerned fuel consumption. With additional fuel cells in the J model P-38, Satan's Angels had been making six and one-half and seven-hour flights. On I July Lindbergh flew a third mission with the group, an armed reconnaissance to enemy strips at Nabire, Sagan One and Two, Otawiri, and Ransiki, all on the western shore of Geelvink Bay. Already Lindbergh's technical eye noticed something. After six and one-half hours flying time, he landed with 210 gallons of fuel remaining in his Lightning's tanks.
Two missions later, on 3 July, the group covered sixteen heavies on a strike against Jefman Island. Lindbergh led Hades Squadron's White Flight as they wove back and forth above the lumbering B-25s. After the attack the Lightning's went barge hunting.
First one, then two pilots reported dwindling fuel and broke off for home. MacDonald ordered the squadron back but because Lindbergh had nursed his fuel, he asked for and received permission to continue the hunt with his wingman. After a few more strafing runs, Lindbergh noticed the other Lightning circling overhead. Nervously the pilot told Lindbergh that he had only 175 gallons of fuel left. The civilian told him to reduce engine R.P.M.'s, lean out his fuel mixture, and throttle back. When they landed, the 431st driver had seventy gallons left, Lindbergh had 260. They had started the mission with equal amounts of gas.
Lindbergh talked with MacDonald. The colonel then asked the group's pilots to assemble at the recreation hall that evening. The hall was that in name only, packed dirt floors staring up at a palm thatched roof, one ping pong table and some decks of cards completing the decor. Under the glare of unshaded bulbs, MacDonald got down to business.
"Mr. Lindbergh" wanted to explain how to gain more range from the P-38s. In a pleasant manner Lindbergh explained cruise control techniques he had worked out for the Lightning's: reduce the standard 2,200 rpm to 1,600, set fuel mixtures to "auto-lean," and slightly increase manifold pressures. This, Lindbergh predicted, would stretch the Lightning's radius by 400 hundred miles, a nine-hour flight. When he concluded his talk half an hour later, the room was silent.
The men mulled over several thoughts in the wake of their guest's presentation.
The notion of a nine-hour flight literally did not sit well with them, "bum-busters" thought some. Seven hours in a cramped Lightning cockpit, sitting on a parachute, an emergency raft, and an oar was bad, nine hours was inconceivable. They were right. Later, on 14 October 1944, a 432nd pilot celebrated his twenty-fourth birthday with an eight-hour escort to Balikpapan, Borneo. On touching down, he was so cramped his crew chief had to climb up and help him get out of the cockpit.
The group’s chief concern surfaced quickly, that such procedures would foul sparkplugs and scorch cylinders. Lindbergh methodically gave the answer. The Lightning's technical manual provided all the figures necessary to prove his point; they had been there all along. Nonetheless the 475th remained skeptical. A single factor scotched their reticence.
During their brief encounter, MacDonald had come to respect Lindbergh. Both men pushed hard and had achieved. Both were perfectionists never leaving things half done. And both had inquisitive minds. John Loisel, commanding officer the 432nd, remembered the two men talking for long periods over a multitude of topics beyond aviation. If, as MacDonald had informed his pilots, better aircraft performance meant a shorter war, then increasing the Lightning's range was worth investigating. Lindbergh provided the idea, but it was MacDonald's endorsement, backed by the enormous respect accorded him by the group, that saw the experiment to fruition. The next day, the Fourth of July, Lindbergh accompanied the 433rd on a six-hour, forty-minute flight led by Captain "Parky" Parkansky. Upon landing, the lowest fuel level recorded was 160 gallons. In his journal entry Lindbergh felt ". . . that the talk last night was worthwhile. " The 475th had lengthened its stride