Let me see if I can summarize your argument to make sure we're on the same page.

I argued that a crucial element of the HK Groups were the airplanes, which reported where the U-boats were. HK Groups started in 1942. Your response to this is that airplanes didn't sink boats alone until 1941.

Is that your argument? If so, then how is it relevant? Whether airplanes killed subs alone before 1941 is completely irrelevant because HK Groups started in 1942. No one suggested that HK Groups relied on airplanes alone. No one suggested that airplanes were the primary sinking force.

Your objections are completely irrelevant to the discussion at hand.

Furthermore I direct you to http://www.uss-corry-dd463.com/d-day...ter-killer.htm wherein we read:

...after dawn, hunter-killer teams of "Wildcats" and "Avengers" scoured the area intensively. The search took all day, but persistence paid dividends. In the waning light of day, Lt.(jg.) Norman T. Dowty sighted a periscope feather wake. He and his wingman, Lt.(jg.) William H. Cole circled, and Dowty swept in for a mine run. They dropped a sonobouy and verified the U-boat's presence as Corry sped to the scene from 15 miles away.
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Planes dropping sonobouys.
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U-801, was totally unaware of Block Island's approach of as she completed surface gunnery practice late on the afternoon of 16 March. Then, one of the Block Island hunter-killer teams, Lt.(jg.) Charles Woodell's "Avenger" and Lt.(jg.) Paul Sorenson's "Wildcat," rudely cut short her drills. Sorenson strafed the surfaced sub, observing hits at the base of the conning tower and inside the bridge while the U-boat's surprised crew scrambled for shelter. After Woodell aborted a bombing run, Sorenson came in for a second strafing run, noticing that fire had broken out on the bridge, apparently from exploding ammunition and burning deck planking. Woodell then made his second pass, loosing two depth bombs which overshot the submarine as she submerged at 1728. At that point, the American planes dropped sonobouys which clearly showed the submarine's track.
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Again, planes dropping sonobouys.
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Finally, at 0900, the new "Avenger" picked up the scent again, dropping a string of float lights to mark the spot. Corry and Bronstein then picked up the contact; and the destroyer attacked at 0942, her depth charges opening a seam in U-801's hull and forcing her skipper to dive deeper. For an hour, the U-boat evaded the attacks, but she continued to leak oil. Around 1140, Corry dropped another pattern of depth charges, and this one proved decisive. With bilge pumps and some switchboards knocked out and her periscope's power having failed, the submarine could not mount a submerged defense, so she had to come up. U-801 lurched to the surface as Block Island, screened by Thomas and Breeman, arrived to witness the last act of the drama.
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Planes directing the escorts to the target.
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The task group scoured the sea during daylight on the 18th and then shaped a southwesterly course that night in the hope of locating another south-bound submarine. Six hunter-killer teams launched at dawn on 19 March fanned out from the warship and covered the area within a 150-mile radius. At 0726, Lt.(jg.) Cole, in his "Wildcat", spotted a submarine ahead, to port of his heading. Flying with the early morning sun at their backs, Cole and Lt.(jg.) Dowty, had surprised the Germans completely. The new 1,100-ton U-1059 lay dead in the water while her captain, Oberleutnant zur See Günter Leopold, joined many of his crew in a morning swim.
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Planes finding subs and attacking.
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As the ship heeled over in her tight turn, one of two General Motors FM-2 "Wildcat" fighter planes launched overhead by Guadalcanal, sighted the submerged U-boat and dived on it, firing into the water to mark the submarine's position. Chatelain steadied up on her sound bearing and moved in for the kill. A full pattern of depth charges set for a shallow target splashed into the water around the U-boat. As their detonations threw geysers of spray into the air, a large oil slick spread on the water; the fighter plane overhead radioed "You struck oil! Sub is surfacing!" Just six and one-half minutes after Chatelain's first attack, U-505 broke the surface with its rudder jammed, lights and electrical machinery out, and water coming in.
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Planes finding the sub and marking its location.
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If that's not enough go to http://www.uboat.net/allies/ships/uss_bogue.htm and read about the planes finding the u-boats and directing the escorts to the sites.

"In reality the US beat the U-boats with air power."

Have a happy New Year, Z.

Well, since we're nitpicking, let me throw in a couple more caveats to remember:

a) Let's not forget the British and other Commonwealth forces - the role played by American ASW forces has been important but very secondary in the Battle of the Atlantic
b) Let's not forget the importance of land-based aircraft and convoy escorts to the formula - these still accounted for the vast majority of U-boat kills over the course of the war and up to its end, compared to HK groups
c) Let's not forget that the U-boats had already lost the Battle of the Atlantic (by any measure, including Doenitz's own wartime assessments) before the first true carrier-based hunter-killer groups scored their first U-boat kill

It would be more accurate to say that the HK groups filled the final gap in the Allied strategy against U-boats, and from the U-boat's perspective were just another threat. In fact it's likely that very few U-boat commanders had much understanding of what they were up against when encountering an allied HK group, and it's even less likely that any of them knew anything at all about the most effective weapon they fielded - the Mk.24 "mine" (aka the FIDO), which is not even actually modeled in SH3.

It's also difficult to escape because of the hydrophone the escorts are using. If u got your enigines at slow speed they can still hear you, but setting it to 1 knot manually can help a lot.

I'm don't know the name of the mod.


@Zosimus Thank you for posting your insight about into your knowledge about anti submarine warfare. Personally I did find it interesting.