the cloud cover, but his wingman, then–Major General Earle E. Partridge, was looking elsewhere and failed to notice Doolittle's quick maneuver, leaving Doolittle to continue on alone on his survey of the crucial battle. Of the P-38, Doolittle said that it was "the sweetest-flying plane in the sky". A little-known role of the P-38 in the European theater was that of fighter-bomber during the invasion of Normandy and the Allied advance across France into Germany. Assigned to the IX Tactical Air Command, the 370th Fighter Group and 474th Fighter Group and their P-38s initially flew missions from England, dive-bombing radar installations, enemy armor, troop concentrations, and flak towers, and providing air cover. The 370th's group commander Howard F. Nichols and a squadron of his P-38 Lightnings attacked Field Marshal Günther von Kluge's headquarters in July 1944; Nichols himself skipped a bomb through the front door. The 370th later operated from Cardonville, France, and the 474th from various bases in France, flying ground-attack missions against gun emplacements, troops, supply dumps, and tanks near Saint-Lô in July and in the Falaise–Argentan area in August 1944. The 370th participated in ground-attack missions across Europe until February 1945, when the unit changed over to the P-51 Mustang. The 474th operated out of bases in France, Belgium, and Germany in primarily the ground-attack missions until November–December 1945. After some disastrous raids in 1944 with B-17s escorted by P-38s and Republic P-47 Thunderbolts, Doolittle, then head of the U.S. Eighth Air Force, went to the Royal Aircraft Establishment, Farnborough, asking for an evaluation of the various American fighters. Test pilot Captain Eric Brown, Fleet Air Arm, recalled: We had found out that the Bf 109 and the FW 190 could fight up to a Mach of 0.75, three-quarters the speed of sound. We checked the Lightning and it couldn't fly in combat faster than 0.68. So, it was useless. We told Doolittle that all it was good for was photoreconnaissance and had to be withdrawn from escort duties. And the funny thing is that the Americans had great difficulty understanding this because the Lightning had the two top aces in the Far East. After evaluation tests at Farnborough, the P-38 was kept in fighting service in Europe for a while longer. Although many failings were remedied with the introduction of the P-38J, by September 1944, all but one of the Lightning groups in the Eighth Air