Most effective nightfighter

[Koopernic]

Was there any real point to the emphasis put on high altitude capabilities of LW night fighters? Aside from the high altitude USAAF night bombing threat that never materialized, there wasn't really any incentive for it. The standard BMW 801 rated altitudes fit well for RAF bomber heights, as did the DB 603A. (and Jumo 213A)

I think the main reason would be flexibility and preparedness. At some point high altitude raids above 20,000ft might commence. A Ju 88G7 with Jumo 213E was not as suitable as a Ju 388J due to the lack of pressurisation but in an emergency it would work. The RAF only need fit two stage Merlins to their bombers and the Luftwaffe might have a problem.

I believe the standard Jumo 213F or E engines of Fw 190D13 designed to carry torpedoes were thought to be a poor fit to the low altitude requirement and were instead to be given a low altitude optimised Jumo 213A.

 

[wuzak]

Was there any real point to the emphasis put on high altitude capabilities of LW night fighters? Aside from the high altitude USAAF night bombing threat that never materialized, there wasn't really any incentive for it. The standard BMW 801 rated altitudes fit well for RAF bomber heights, as did the DB 603A. (and Jumo 213A)

Mosquito Pathfinders.

 

[Edgar Brooks]

The RAF only need fit two stage Merlins to their bombers and the Luftwaffe might have a problem.

It was never going to happen; much is continually made of the Lancaster's "inability" to climb above 18,000', but the Air Ministry didn't want that, anyway. Contrails start at around 20,000', and the authorities didn't want each bomber to trail four pointing white fingers as an invitation to any nightfighter, when they were supposed to be trying to hide in the cloak of darkness.

 

[Edgar Brooks]

The RAF only need fit two stage Merlins to their bombers and the Luftwaffe might have a problem.

It was never going to happen; much is continually made of the Lancaster's "inability" to climb above 18,000', but the Air Ministry didn't want that, anyway. Contrails start at around 20,000', and the authorities didn't want each bomber to trail four pointing white fingers as an invitation to any nightfighter, when they were supposed to be trying to hide in the cloak of darkness.

 

[Juha]

It was never going to happen; much is continually made of the Lancaster's "inability" to climb above 18,000', but the Air Ministry didn't want that, anyway. Contrails start at around 20,000', and the authorities didn't want each bomber to trail four pointing white fingers as an invitation to any nightfighter, when they were supposed to be trying to hide in the cloak of darkness.

They modified 9 B.IIIs to B.VIs with Merlin 85s/87s, but these had technical difficulties and while most of them were used operationally in Pathfinder units they were withdrawn from ops in Nov 44, maybe partly for the reason you gave.

 

[kool kitty89]

Mosquito Pathfinders.

Were any of the aircraft in question even fast enough (with high alt engines or GM-1 boost) to actually make the effective against Mosquitoes, especially the 2-stage merlin powered ones?

It doesn't seem like the Ju 88 or even Me 410 fit the mosquito chasing role very well. (the Ar 240 might have had potential to do so -especially with DB-605s or 603s, the Fw 187 probably would have worked as the basis for that too once compact enough radar was available -or much earlier in terms of countering daylight Mossie operations)

 

[SpicyJuan11]

Were any of the aircraft in question even fast enough (with high alt engines or GM-1 boost) to actually make the effective against Mosquitoes, especially the 2-stage merlin powered ones?

It doesn't seem like the Ju 88 or even Me 410 fit the mosquito chasing role very well. (the Ar 240 might have had potential to do so -especially with DB-605s or 603s, the Fw 187 probably would have worked as the basis for that too once compact enough radar was available -or much earlier in terms of countering daylight Mossie operations)

What about the Arado 240/440 with Jumo 222's, or would it just have been best to give them to the Ju 88's?

 

[GrauGeist]

Were any of the aircraft in question even fast enough (with high alt engines or GM-1 boost) to actually make the effective against Mosquitoes, especially the 2-stage merlin powered ones?

It doesn't seem like the Ju 88 or even Me 410 fit the mosquito chasing role very well. (the Ar 240 might have had potential to do so -especially with DB-605s or 603s, the Fw 187 probably would have worked as the basis for that too once compact enough radar was available -or much earlier in terms of countering daylight Mossie operations)

The He219...

 

[wuzak]

The He219...

....couldn't really catch Mosquitoes either.

 

[mhuxt]

The He219...

... had the same engines as the 410 on a heavier airframe.

 

[kool kitty89]

....couldn't really catch Mosquitoes either.

It also started development much later and was larger and heavier and had fewer advantages over the Me 410 and Ju 88. The Ar 240 and Fw 187 were both early/pre-war designs with a great deal more potential for developing into effective combat aircraft in a timely manner had there been the support/interest from the RLM.

The Ar 240 already did well with DB 601Es and certainly should have improved with 605s. 603s might actually be less useful given the added weight, drag. and greater usefulness of those engines on the likes of the Do 217 and Fw 190. (while avoiding the Me 410 entirely) Jumo 211s might also be useful.

Actually getting counter-rotating engines in production might have been significant as well. (useful for all twins, but with the Ar 240 in particular, counter-rotating engines might have improved some of its handling problems)

What about the Arado 240/440 with Jumo 222's, or would it just have been best to give them to the Ju 88's?

Too heavy and bulky for the aircraft. DB 603s might have been OK but given how well it did with DB 601s, it seems like DB 605s or later Jumo 211 models would be more suitable. Sticking with refining the basic Ar 240 design also seems more sensible than switching over to the larger Ar 440. (admittedly, I'm not sure how much of the design carried over, but the implications seems to be it was a significant redesign and at least somewhat larger and heavier)

 

[SpicyJuan11]

It also started development much later and was larger and heavier and had fewer advantages over the Me 410 and Ju 88. The Ar 240 and Fw 187 were both early/pre-war designs with a great deal more potential for developing into effective combat aircraft in a timely manner had there been the support/interest from the RLM.

The Ar 240 already did well with DB 601Es and certainly should have improved with 605s. 603s might actually be less useful given the added weight, drag. and greater usefulness of those engines on the likes of the Do 217 and Fw 190. (while avoiding the Me 410 entirely) Jumo 211s might also be useful.

Actually getting counter-rotating engines in production might have been significant as well. (useful for all twins, but with the Ar 240 in particular, counter-rotating engines might have improved some of its handling problems)



Too heavy and bulky for the aircraft. DB 603s might have been OK but given how well it did with DB 601s, it seems like DB 605s or later Jumo 211 models would be more suitable. Sticking with refining the basic Ar 240 design also seems more sensible than switching over to the larger Ar 440. (admittedly, I'm not sure how much of the design carried over, but the implications seems to be it was a significant redesign and at least somewhat larger and heavier)

The 440 was quite different than the 240 (longer fuselage, heavier armament, DB 603's, four bladed props, larger wing area), and AFAIK corrected the 240's handling woes, but still had enough in common to show that the Arado 240's design was workable.

 

[kool kitty89]

The 440 was quite different than the 240 (longer fuselage, heavier armament, DB 603's, four bladed props, larger wing area), and AFAIK corrected the 240's handling woes, but still had enough in common to show that the Arado 240's design was workable.

Looking at this thread: http://www.ww2aircraft.net/forum/aircraft-requests/ar-440-a-734.html

It appears the sole Ar 440 prototype was converted from the 4th preproduction Ar 240 (Ar 240A-04), it was some 3000 kg heavier (9200 vs 6200 kg empty) though max takeoff only managed less than 2000 kg greater than the Ar 240A-0.
while having the wing span and area increased from 13.34 m to 16.3 m, the area only increased from 31.3 m^2 to 34 m^2, so aspect ratio would be higher but wing loading would be significantly higher as well.

The whole transition seems to be a waste of time and resources compared to refining the existing Ar 240 design. The 440 was significantly faster but it seems to have achieved this partially at the expense of even greater extremes of the same sorts of compromises made for speed on the previous Ar 240 while also having the advantage of engines with substantially better altitude performance than the 601E. (not to mention being larger and more costly/resource hungry -including using those DB-603s)

It seems like deleting the defensive armament and focusing on addressing the remaining handling issues would be most important, along with adapting more powerful DB-605 and/or Jumo 211 engines. And it should still make a better fast, tactical level/(shallow)dive bomber than the Me 410 ... or Me 262, likely Ar 234 as well (though the latter should still make a better recon aircraft) while potentially ready for service considerably earlier than any of those. (or at least modestly sooner than the Me 410, perhaps more in line with the initial introduction of the Me 210 ... or sooner had as much resources been allocated to Arado's program as the 210 got)

The Ar 440's larger wing might have been more useful applied to a high-altitude variant of the smaller 240, particularly once DB 605AS engines became available.

 

[SpicyJuan11]

Looking at this thread: http://www.ww2aircraft.net/forum/aircraft-requests/ar-440-a-734.html

It appears the sole Ar 440 prototype was converted from the 4th preproduction Ar 240 (Ar 240A-04), it was some 3000 kg heavier (9200 vs 6200 kg empty) though max takeoff only managed less than 2000 kg greater than the Ar 240A-0.
while having the wing span and area increased from 13.34 m to 16.3 m, the area only increased from 31.3 m^2 to 34 m^2, so aspect ratio would be higher but wing loading would be significantly higher as well.

The whole transition seems to be a waste of time and resources compared to refining the existing Ar 240 design. The 440 was significantly faster but it seems to have achieved this partially at the expense of even greater extremes of the same sorts of compromises made for speed on the previous Ar 240 while also having the advantage of engines with substantially better altitude performance than the 601E. (not to mention being larger and more costly/resource hungry -including using those DB-603s)

It seems like deleting the defensive armament and focusing on addressing the remaining handling issues would be most important, along with adapting more powerful DB-605 and/or Jumo 211 engines. And it should still make a better fast, tactical level/(shallow)dive bomber than the Me 410 ... or Me 262, likely Ar 234 as well (though the latter should still make a better recon aircraft) while potentially ready for service considerably earlier than any of those. (or at least modestly sooner than the Me 410, perhaps more in line with the initial introduction of the Me 210 ... or sooner had as much resources been allocated to Arado's program as the 210 got)

The Ar 440's larger wing might have been more useful applied to a high-altitude variant of the smaller 240, particularly once DB 605AS engines became available.

Could the 240 have been a better escort/heavy fighter than the Fw 187 if it deleted the second crew-man, tried to save more weight, and have larger wings? Or did the Fw 187 still outclass it?

 

[Shortround6]

Could the 240 have been a better escort/heavy fighter than the Fw 187 if it deleted the second crew-man, tried to save more weight, and have larger wings? Or did the Fw 187 still outclass it?

A escort/heavy fighter has to be able to duke it out, at least somewhat, with the single engine, single seat interceptors. Starting with a large, heavy airplane and trying to cut it down just means a lot of work for little result. A 240 weighed about 1/2 ton more empty than a late model P-38. And empty means no guns (although mounts are there) Gross weight clean was well over a ton more than the P-38. And the P-38 was no great shakes against 109s and 190s for a good part of the war.
By the time you cut down the cockpit, ditch the turrets, install forward firing guns and change the wing what have you kept except the engines, landing gear and the name?

 

[SpicyJuan11]

A escort/heavy fighter has to be able to duke it out, at least somewhat, with the single engine, single seat interceptors. Starting with a large, heavy airplane and trying to cut it down just means a lot of work for little result. A 240 weighed about 1/2 ton more empty than a late model P-38. And empty means no guns (although mounts are there) Gross weight clean was well over a ton more than the P-38. And the P-38 was no great shakes against 109s and 190s for a good part of the war.
By the time you cut down the cockpit, ditch the turrets, install forward firing guns and change the wing what have you kept except the engines, landing gear and the name?

Oh my, yes I didn't realize how heavy the Arado was

 

[kool kitty89]

Oh my, yes I didn't realize how heavy the Arado was

Indeed, more in the class of the single stage engined fighter-bomber Mosquitos, but with smaller wing area. The weight also makes its climb performance rather mediocre (again somewhat like the Merlin XX powered Mosquitos with combat load) so probably wouldn't make a great interceptor either. (even with fighter escort the poor climb would slow down interception as well as making it more vulnerable to enemy fighters)

Or at least assuming wiki's climb figure is accurate. (seems reasonable given the power/weight and wing loading, though it would obviously vary by altitude I assume it's initial climb as is usually cited -not always best climb, but with the DB's power curve, probably not far off)

The Fw 187 was never tested with DB 601Es (or Ns for that matter) and the DB-600s it was tested with were fairly low altitude engines as well as using surface cooling in the wings (so another odity of reduced drag but also less power or altitude performance than DB 601s were offering). I believe there was one prototype later refitted with DB 601 engines though the cooling arrangement seems in contention (it was either an early example of pressurized cooling with conventional, retractable radiators or again using surface cooling). I forget the exact speed, but the 601 powered prototype managed over 400 MPH at altitude. (I want to say it was around 415 MPH, but I'd have to find the quote again to be sure)

I think it's fairly safe to assume that with a combat load similar to the A-0 models (either still a 2-seater or a more heavily armed single seater, possibly with more fuel and armament -and added weight from self sealing tanks in either case; plus reasonably low-drag embedded or retractable radiators) it seems safe to say that with DB-601E engines (or Jumo 211Fs) it could have still managed above 400 MPH top speed at best altitude. Faster than the Ar 240 with those engines and a great deal lighter (and should climb significantly better). It should also be somewhat lighter than the P-38 of around the same time.

The A-0 models themselves might have been a bit faster if not for the switch to bulkier fixed radiators. Their speed was only slightly better than the lighter single-seat prototypes with less powerful engines. Even with the second crewman, it should have been a bit faster with more streamlined radiators. (and it STILL was slightly faster than the Bf 109E up to the Jumo 210G's critical altitude, but that was several thousand feet lower than the 109E's)


But again, the Fw 187 wouldn't work as a (radar equipped) night fighter until late war with more compact radar. (similar to the case for the P-38M)