OK, while I agree with posters who say the whole idea is almost poppycock based on OTL developments, is there a way to imagine a fairly recent PoD which would allow Germany to mount a fairly substantial air raid on New York or someplace else on the eastern US seaboard by 1943, in a WW2 which was basically similar to the one in our TL. To do this you have to go back well before the war...and forget planes like the Me-264 and Fw-300.
I offer this:
Shortly after Hitler's assumption of power, the German air ministry was seriously pursuing 4-engine long-range strategic bombers ("Ural Bombers") as a high priority, resulting in two prototypes, the Do-19 and Ju-89. Shortly after the first prototypes flew, the main supporter of the strategic bomber, General Walther Wever, died, and all Luftwaffe focus went to medium bombers and ground support aircraft. The Ju-89 and Do-17 were cancelled. The followup "Bomber A" heavy bomber program was a fairly low priority and, because the RLM demanded high maneuverability and dive-bombing ability, the resulting He-177 was a failure and Germany never has an meaningful long- range bomber force. But what if Wever had not died, and the development of larger and ever more capable strategic bombers remained at the core of German aviation strategy?
February, 1937, the Ju-89 is selected over the Do-19 and an initial production run of 200 machines is ordered, the first entering service with KG15 in October 1937. At the same time, attempting to ensure Germany remains in the forefront of the field, the RLM issues a request for proposals from Junkers, Dornier, and Heinkel for a new follow on 4-engine heavy bomber which must be capable of expansion to a larger 6-engined bomber by the fairly simple expedient of adding fuselage bays and wing sections. Even this early, the RLM was envisioning a possible war with the USA and wanted to have a plane capable of at least one-way strikes on US territory from bases in Europe, resulting in the secret and unofficial term "Amerikabomber" for the program.
October 1939, the first of the "Amerikabomber" prototypes, the Ju-189, flies, followed by the Dornier Do-217, and the Heinkel He-222. After exhaustive tests, the Do-217 is selected for production, with the Ju-189 accepted as a backup.
May, 1940, the first production Do-217A enters service. The Do-217 is a high wing, deep bodied plane, powered by 4 BMW-139 radial engines. The bomber looks, in fact, like a flying boat, which is not surprising because it was closely based on a prewar transatlantic flying boat design, which also reaches production as the Do-217B. The Do-217 is thus unique, in that throughout its service life, it was produced in both landplane and flying boat variants, the two finally being merged in the Do-217E of 1942.
Both the aging Ju-89 and a few squadrons of the new Do-217 serve during the Battle of Britain. The Ju-189 never entered service. The brunt of the offensive is born by 1000's of Ju-89's, supplemented by He-111 medium bombers. Although the Ju-89 is capable of bombing targets anywhere on the British Isles, its extremely slow speed and limited defensive armament render it completely helpless outside the much more limited range of the Luftwaffe's Bf-109 and He-112 fighters. The few Do217's committed to the Battle do quite well, being faster then either other German bomber and having an effective defensive armament of 10 heavy machine guns and 20 mm cannon in power-operated turrets.
February, 1942. The US finally enters the war and the RLM realizes that the basic Do-217 lacks the endurance to reach North America and return, and - even on a one-way trip - the offensive load would be very limited. At RLM request, Dornier offers two alternative designs for a true transatlantic bomber: (1) the Do-317, a very advanced pressurized 6-engined bomber based only loosely on the the landplane Do-217D, and (2) the Do-217Z, a Zwilling, or twin, version of the basic Do-217E amphibious floatplane bomber just being introduced in prototype form. The RLM accepts the Do217Z, citing the success of Heinkel's similar He-111Z glider tug, and the fact design and construction of the Do-217Z would be simplified due to its commonality with the production Do-217E. The RLM also found merit in the Do-217Z's amphibious capability - it was essentially a floatplane and could land in emergency in sheltered waters - a capability which formed the basis of the audacious plans which followed.
November, 1942. The first Do-217Z takes to the air in floatplane form, and Hitler declares the project his "Vengeance Weapon 1" or V1. The program receives highest priority for production and deployment. The Do-217Z is a 6-engined plane combining two complete Do-217E fuselages, mated together by a completely new nacelle where the outside 4th engine of each plane would be, this nacelle carrying two engines and a small internal weapons bay to supplement the external hard points under the wings and other engine nacelles. With a wingspan approaching 200 feet, the Do-217Z is the largest airplane built in Germany. The plane is a poor performer, with a service ceiling of little more than 15,000 feet, a maximum speed barely over 200 mph, and a negligible defensive armament. Virtually everything has been sacrificed to obtain the greatest possible range, and with its deep fuselages filled with temporary fuel tanks to supplement the standard wing tanks, it is calculated the plane can easily reach targets throughout northern and eastern north America. At such ranges its bomb load is quite limited, but bombs are bombs, and Hitler is demanding some be dropped on the US by the end of 1943 or heads will roll!
August, 1943.
Only 31 Do-217Zs, out of the total production order of 250 have been completed, and have been delivered to the Luftwaffe "Horst Wessel Vengeance Weapon 1 base" in an isolated Norwegian fiord. They have been effectively hidden from RAF aerial recon by camouflage netting...and the existence of the Do-217Z is completely unknown to Allied intelligence. Otto Skorzeny, the famous SS officer, has been placed in charge of the overall operation.
August 25, 1943.
The raid commences. Skorzeny's plan is to fly his entire force of 31 Do-217Z's in groups of twos and threes on a high polar route over northern Greenland and the largely unpopulated Canadian Northwest Territories and attempt a water-borne rendezvous near the northern Coast of Ontario on Hudson Bay. At Hitler's express orders, the ultimate target is New York City, hated symbol of American capitalism, racial impurity, and world Jewry. Being a realist, Skorzeny modifies those orders to allow planes to attack any target of opportunity along the way, should they be discovered or have mechanical problems. The final run to New York from Hudson Bay is scheduled so that as much of the flight as possible will occur at night, and each plane's radioman is a fluent english speaker to hopefully help confuse any Canadian or US traffic controllers should the planes be discovered by radar before they reach strategic targets. Skorzeny's plan is based on the hope that US and Canadian radars and air defenses will deployed to watch for attacks from the Atlantic, not a squadron of lumbering heavy bombers coming in from the northwest over some of the most densely occupied areas of the US Midwest. Although he tells no one, Skorzeny is not hopeful that any men on this mission will make it home...death or, at best, prison will await them. His only hope is he will make the Americans pay.
The raid begins inauspiciously, as one Do-217Z suffers a catastrophic structural failure on takeoff, the twin planes separating at the central nacelle and both crashing into the water and exploding. The rear engine in the central nacelle of another plane catches fire and its crew is ordered to return to base.
Flying in the allotted small formations, the remaining Do-217Z's fly over the frigid arctic wastes and begin arriving undetected at the rendezvous point on Hudson Bay during the early morning hours of August, 26. Skorzeny is pleased to see that the sea is smooth as glass and there is no sea ice to worry about in the planned landing zone. Nonetheless, one Do-217Z suffers an engine failure on the outside starboard engine while touching down, the pilot overcompensates driving the port wingtip into the water, and his huge bomber flips over and disintegrates into the icy sea, its entire crew dying of hypothermia as their mates watch. So, even before seeing any enemy action, the strike force is down to 27 planes.
August 26. Skorzeny's force begins its final leg at dusk. All 27 planes make it off the sea and claw toward their operating ceiling of 13,000 feet, crossing the Ontario coast near the mouth of the Severn River. They are flying in a very loose formation, with each plane separated by several miles. As Skorzeny hoped, the raiders are able to reach the north coast of Lake Superior without being spotted or challenged. The planes then fly southeast over the Great Lakes on a course intended to minimize overland flight, crossing only the tip of the Michigan northern peninsula. From here on out, Skorzeny knows things will get extremely tricky once he has to proceed overland. Not only will he now be in a densely populated area, daybreak will occur shortly after he crosses Lake Eire and enters the US near the Pennslyvania-New York border.
Yet his luck holds. Amazingly, all 27 planes make it over southern Ontario unchallenged, and as he crosses into the US, it is beginning to look like the Americans really have not considered the potential of any air raids from Canada!
As the sun rises, showing a low overcast covering the western Pennsylvania hills, Skorzeney's spirits rise even further. As long as the ground-level visibility remains poor, he only has to worry about radar contacts or encountering another plane. He begins to think his mission may actually succeed and at least a few of his men may get home, one way or, another.
Near Scranton, however, things suddenly go terribly wrong. Rear engines on the central nacelles of two lumbering Do-217Z's overheat and catch fire. One plane tumbles out of the sky as the burning nacelle holding the two twin components together disintegrates; the other is able to extinguish the fire, but on only five engines, the heavily loaded Do-217Z gradually loses altitude and disappears into the cloud layer 5000 feet below. Skorzeny winces. "Damn," he mutters, "Americans may be mongrel fools, but even an ape will see those planes when they hit the ground." Knowing the element of surprise will soon be lost, Skorzeny orders 20 of his planes to disperse and seek out one or more of the pre-planned secondary targets identified in eastern Pennsylvania, New Jersey, and New York. He splits the remaining 5 planes into two groups, one containing two planes which will head toward Washington and three under his command will head toward New York. Hopefully, this tactic will confuse the Americans as they pursue the scattering attackers and at least somebody will get through. Unfortunately for Skorzeny, the low overcast which helped him earlier is now a hindrance. Flying at 13,000 feet, his pilots cannot see any landmarks and are essentially trying to find their way blind. Skorzeny only hopes the low fog and clouds dissipate as the summer sun rises so they can find their targets.
Fifteen minutes later, the Germans in Skorzeny's flight see their first American planes - a loose gaggle of three P-40's and what looks to be several P-38's breaking through the cloud cover below them and several miles behind. His only chance is to dive the huge bombers to the clouds himself and hope that he can reach them before the fighters do.
Thus began the only successful German air attack on the US during the Second World War. Of Skorzeny's remaining force of 25 Do-217Z, six were shot down by fighters before they could find good targets of opportunity, and one was destroyed by 90mm AA fire as it attempted to bomb a US Steel complex near Allentown, Pennsylvania. Two planes successfully bombed a railyard in Reading, Pennsylvania, causing several hundred thousand dollars worth of damage and killing 25 people, all civilians. The planes then crash-landed nearby and all survivors were taken prisoner. Three made it to Philadelphia where they dropped their bombs over the central downtown district, causing substantial damage to several downtown buildings, killing 76 people, and narrowly missing Independence Hall, which may have been their intended secondary target. All three planes were shot down by AA and, with the exception of a few lucky crewmen who bailed out and avoided being lynched, all perished. Another thee bombers crossed into New Jersey and were shot down by AA as they attempted to bomb dock facilities along the Hudson River in Newark. Five more planes were intercepted and shot down by fighters at various locations in eastern Pennsylvania as they were looking for targets of opportunity. The group Skorzeny sent toward Washington never made it, falling to concentrated AA fire as the crossed the Maryland border into the District of Columbia. It remained for Skorzeny to strike the final blow. Bouncing in and out of the low cloud cover, his three planes finally emerged over the Hudson River near midtown Manhattan. Rather than fly low and fast over the city and randomly drop their minuscule bomb loads with little real effect, and knowing that the possibility of making it back across the Atlantic to France alive was virtually impossible, Skorzeny ordered his three planes to pick the most visible landmarks they could see and try to ram them, regardless of whether or not the crews could bail out. One plane set its course toward the lower end docks, which were jammed with troopships, converted liners, and a few destroyers. Although hit by AA, the flaming plane struck a docked troopship amidships, its flaming fuel and bombs igniting a massive fire and killing as many as 1,500 military personnel and 150 civilian dockworkers. The remaining two planes headed toward the Empire State Building. Flak had become very intense, setting both planes ablaze. However, both were able to strike the target, and after their crews had successfully bailed out, including Skorzeny. The first plane was disintegrating as it clipped the building at approximately the 75th floor, causing negligible damage to the structure but sending flaming debris into the cleared streets below. Skorzeny's crippled plane plowed directly into the building near the base of the mooring tower. In the resulting explosion and fire, the tower and at least ten uppermost storys of the building were totally destroyed, but thanks to effective civil defense measures, the building had been vacated and there were no casualties. A number of Luftwaffe crewmen were killed as they parachuted down into the sides of buildings and other obstructions, six others were mobbed and killed by an angry crowd before the NYPD or National Guard could arrive. All told, Skorzeny and 12 other crewmen assigned to this mission survived. The enlisted Luftwaffe personnel spend the rest of the war in a POW camp. Skorzeny and 3 other SS officers were tried by a military tribunal, convicted of violating the rules of war, and executed on December 7, 1943.