My opinions on this issue are that the US undertook both daylight and night time bombing, whilst the RAF undertook Night bombing and later daylight bombing. Both forces encountered no real problems in the changeover.
For the US, the best example I can think of is in the bombing of japan. The B-29 raids started as high level HE raids, carried out in daylight, and were not particulalry effective. Having witnessed the effectiveness of the RAF mass incendiary raids over germany, the US switched to low level (ie 20'K) incendiary bombing, that in the fuel rich cities of Japan was exceptionally effective.
Conversely, the RAF, having been forced to use night bombing techniques witnessed the devatating effects the precision attacks of the USAAF on German industry, and increasingly switched their heavy bombers to daylight attacks as the war progressed.
The secret to successful daylight attacks was the control of the skies, I would suggest, and not the bomber type flying them. US B-17s and B-24s had no more success in Daylight than any other type, whilst the LW was in control of the skies around them. Add a LR escort like a P-51 and the equation changes fundamentally, and more or less instantly. The RAF was abale to use its heavy bombers in daylight because the US had won air superiority by that stage.
With regard to Night bombing, it was not necessary for the US to escort their B-29 raids at night, because the japanese lacked an effective Night Fighter force. For the RAF this was not the case....they were faced with a highly efficient enemy NF force. With respect to the comments being bandied about about the RAF not escorting their Night bombers, this is, with respect, bunkum. The RAF in fact employed over 140 Mosquitoes alon, on average, as Direct escort, and a furthe 14 squadrons (numbers unknown, but approximately 300) as Night intruders, that turned the German Night Fighters lives into a nightmare, to be brutal about it. So rattled were the NJGs by the end, that more were being lost in landing accidents than any the 600 or so that were lost to direct escort. Be all that as it may, the British managed to reduce their loes from an average of 7% to less than 2%...some of this was due to a shortage of fuel, but some was also due to the effects of the escorts being provided to the bomber forces, particulalry after June 1944. All this argument about only a few RAF pilots having the skill to escort at night is utter rubbish, to be brutal about it, though, like all airforces, 90% of the killing was done by 10% of the pilots. RAF training emphasized that all pilots were trained for the job at hand, and given the throrouhness of the electronic training and familiarization, it should come as no surpise that most of the Night Fighter aircrews were fully upto the task of direct escort.
