USAAF forever.

[galveston bay]

I hadn't even thought of that. But maybe an electronically-steered antenna could be built into the hull, or even form part of the structure. All other things being equal, aperture size is one of the factors that determines radar performance, and the idea of an airborne radar with an aperture measured in the tens of meters is... intriguing.
I have to admit, though, that airships have a strictly limited utility in realistic TLs like this one. The idea has grown on me, but the reason I brought it up originally is that as a new member I'm required to make implausible posts about either a) Unmentionable marine mammals, b) the Confederacy, or c) airships. Preferably nuclear-powered airships, made by Russians. Just trying to do my job.

Russian Nuclear powered airships are always fun

as to Airships being used as airborne radar platforms..

http://en.wikipedia.org/wiki/N-Class_Blimp

but one of the first airborne early warning planes was the TBF Avenger

 

[Just Leo]

For a primitive AWACS (if--BIG IF--anyone thinks up the idea without modern hindsight) it'd be a Mars rather than a 314 (which, interestingly, was militarized into the B-18 Bolo...exact same wing).

The Boeing 314 used the wing of a B-15 with engines changed to Wright R-2600. The B-18 Bolo used the wing of the DC-3/C-47 Gooney Bird.
The PBY is a flying boat.

 

[Gunnarnz]

as to Airships being used as airborne radar platforms..

http://en.wikipedia.org/wiki/N-Class_Blimp

but one of the first airborne early warning planes was the TBF Avenger

I remembered the Avenger being used in that role, but I didn't realise anyone had actually gone ahead and actually used an airship as a radar platform... wow. An impressive piece of engineering.

 

[Geekhis Khan]

I think we're having a definition disagreement: I was considering the PBY a seaplane, not a flying boat. Since it does have a boat hull, it probably is technically a flying boat, but I reserve that term for thinks like the Boeing Clippers.

The PBY certainly played a key role in the war.[/QUOT or not.E]

Yes, the PBY is considered a Flying Boat or an Amphibian, depending on if it's a model with retractable wheels. A Seaplane would technically be a plane with pontoon-style floats rather than landing gear.

And recall our earlier conversations on patrol Flying Boats to close the Atlantic gap: British Sunderlands and US Martins.

I hadn't even thought of that. But maybe an electronically-steered antenna could be built into the hull, or even form part of the structure. All other things being equal, aperture size is one of the factors that determines radar performance, and the idea of an airborne radar with an aperture measured in the tens of meters is... intriguing.
I have to admit, though, that airships have a strictly limited utility in realistic TLs like this one. The idea has grown on me, but the reason I brought it up originally is that as a new member I'm required to make implausible posts about either a) Unmentionable marine mammals, b) the Confederacy, or c) airships. Preferably nuclear-powered airships, made by Russians. Just trying to do my job.

Well, this early before the cavity magnetron (German invention, IIRC) most allies radars would be lower frequency (like HF range) so using the whole structure as the antenna makes a lot of sence. Crazy idea: rather than a directional antenna with pulsed modulation, why not a bistatic transmitting from the fuselage and receiving via another antenna?

The Boeing 314 used the wing of a B-15 with engines changed to Wright R-2600. The B-18 Bolo used the wing of the DC-3/C-47 Gooney Bird.

Ah, yes, my bad.

 

[Gunnarnz]

Well, this early before the cavity magnetron (German invention, IIRC) most allies radars would be lower frequency (like HF range) so using the whole structure as the antenna makes a lot of sence. Crazy idea: rather than a directional antenna with pulsed modulation, why not a bistatic transmitting from the fuselage and receiving via another antenna?

I'm having this vision of a huge blimp-based bistatic radar transmitter and a fleet (flock? covey? squadron?) of seaplanes fitted with receivers for it; racing around and chasing down the blips for visual examination. Dog alone knows how that could become an accepted way to run a patrol pattern, but it has a crazy kind of quaint charm.

Edit: Just on the subject of that Bat guided bomb, the Wikipedia link said that it had a great degree of trouble with terminal homing since it had a tendency to home in on anything that reflected a radar beam - including ground clutter or other objects. Would it be possible for this to see service as an anti-shipping weapon? Depending on the sea-state there's less of a ground-clutter problem, and as has been mentioned elsewhere ships have a rather large thermal footprint. Was infra-red technology of the time advanced enough to have been used as an additional form of target discrimination? I know both the Germans and USA experimented with active-IR searchlights and sniper-scopes, but I don't know what the story was with passive sensors. It doesn't have to be a thermal imager, just something to go for a large blob of heat.

 

[Just Leo]

The Germans discovered the multi-cavity magnetron in 1943, in the rubble of a Lancaster's H2S unit. Randall and Boot were a little before.

 

[FleetMac]

Edit: Just on the subject of that Bat guided bomb, the Wikipedia link said that it had a great degree of trouble with terminal homing since it had a tendency to home in on anything that reflected a radar beam - including ground clutter or other objects. Would it be possible for this to see service as an anti-shipping weapon? Depending on the sea-state there's less of a ground-clutter problem, and as has been mentioned elsewhere ships have a rather large thermal footprint. Was infra-red technology of the time advanced enough to have been used as an additional form of target discrimination? I know both the Germans and USA experimented with active-IR searchlights and sniper-scopes, but I don't know what the story was with passive sensors. It doesn't have to be a thermal imager, just something to go for a large blob of heat.

Actually it was deployed in an anti-shipping role: they just didn't have the most reliable accuracy as you've already said. (Source). And anti-shipping strikes are indeed a good field of application for IR guidance. Think about it; warships have very warm power-plants (especially CODAG at high speed), and your backdrop is either the ocean or open air, both of which are at ambient temperatures (I guarantee it won't be as hot as a ship's engines). It's one of many reasons why I feel trying to go "stealthy" with destroyers and whatnot is pure folly. Reducing a radar return is one thing, but trying to build a seaborne F-22? Not gonna happen. You want invisibility at sea, get a submarine.

 

[Just Leo]

Actually it was deployed in an anti-shipping role: they just didn't have the most reliable accuracy as you've already said. (Source). And anti-shipping strikes are indeed a good field of application for IR guidance. Think about it; warships have very warm power-plants (especially CODAG at high speed), and your backdrop is either the ocean or open air, both of which are at ambient temperatures (I guarantee it won't be as hot as a ship's engines). It's one of many reasons why I feel trying to go "stealthy" with destroyers and whatnot is pure folly. Reducing a radar return is one thing, but trying to build a seaborne F-22? Not gonna happen. You want invisibility at sea, get a submarine.

While a destroyer's engines may produce a signature, the F-22's engines also produce heat, slightly reduced with supercruise, and it was over thirty years ago that all-aspect IR missiles began to home on airframe heating, a condition not suffered by destroyers.

 

[Gridley]

as to Airships being used as airborne radar platforms..

http://en.wikipedia.org/wiki/N-Class_Blimp

I'd never heard of those - nifty! Hmmm...

most allies radars would be lower frequency (like HF range) so using the whole structure as the antenna makes a lot of sence.

And another hmmm....

And anti-shipping strikes are indeed a good field of application for IR guidance. Think about it; warships have very warm power-plants (especially CODAG at high speed), and your backdrop is either the ocean or open air, both of which are at ambient temperatures (I guarantee it won't be as hot as a ship's engines). It's one of many reasons why I feel trying to go "stealthy" with destroyers and whatnot is pure folly. Reducing a radar return is one thing, but trying to build a seaborne F-22? Not gonna happen. You want invisibility at sea, get a submarine.

Airplane engines burn plenty hot, trust me. They're also much closer to the skin of the plane than a ship's engines are to the deck. While it is a technical challenge to vector your waste heat in a desired direction, I'm quite sure a ship can do it if the designer accepts the tradeoffs. Whether the restrictions on the design space are worth it is, of course, a separate question.

On the RAWC (Radar-equipped Airship, Warning and Control) idea, don't forget the PoD is keeping Moffett alive, and he was an airship fan. Even after recognizing their limits, he's going to have an eye out for opportunities to take advantage of their strengths, AND he's got the political skills to get a project funded. As the potential power of aircraft is realized in the late 1930s, the idea of putting a really big radar up high and with a long on-station time will be appealing for air defense. The range of the radar would mitigate the vulnerability of the platform.

What if even a single prototype happened to be conducting trials over Pearl Harbor on TTL's equivalent of December 7th, 1941?

 

[Bureaucromancer]

I've mentioned it already, but if we are looking at airships again any one not familiar with Zoomar's TL should take a look. Maybe a bit wankish, but much less so than most airship TLs, and does use them in a plausible role (the same one the blimps were OTL in fact, but with more teeth). I can definitely see radar work being done if there are any large ships available as the equipment become practical...

 

[FleetMac]

AEW and ASW are pretty much the best (and only) roles for zeppelins/airships in the modern age; luckily, as already mentioned, they seem to have quite a few advantages in those areas. Another plus is that they have comparatively large crews, which just adds to their endurance since they can keep up a decent watch bill and not suffer crew fatigue.

 

[Just Leo]

AEW and ASW are pretty much the best (and only) roles for zeppelins/airships in the modern age; luckily, as already mentioned, they seem to have quite a few advantages in those areas. Another plus is that they have comparatively large crews, which just adds to their endurance since they can keep up a decent watch bill and not suffer crew fatigue.

DARPA seems to agree that the AEW role is viable, the latest trend is unmanned solar-panel equipped units that stay up for ten years.

In the ASW role, the history of success in attack is pretty poor, but the record of success in prevention is unsurpassed.

 

[Gridley]

I'm considering sliding back the PoD a few years - the net results will be extremely similar, but it occurred to me that I might be able to achieve my goals with a PoD that kills Douglas MacArthur; killing him is bound to happen in any TL I write about the war, so it seems reasonable to make it the PoD.

I've resurrected another thread to discuss replacing Mac as Army Chief of Staff, and I'd like to invite posts there on non-aviation effects of killing him circa 1930 and here on aviation effects of killing him (one butterfly will be that Moffett is not killed in 1933).

 

[soutgun2]

WOW

I have just read all 16 pages of this thread. I knew a small bit of what was written and learned so much more. Thank you all! An Army hold on Tac Air and the Navy filling out the other roles. That was my thoughts on aircraft and their roles.